null  null
Open On-Chip Debugger:
OpenOCD User’s Guide
for release 0.6.0
7 September 2012
This User’s Guide documents release 0.6.0, dated 7 September 2012, of the Open On-Chip
Debugger (OpenOCD).
c 2008 The OpenOCD Project
• Copyright c 2007-2008 Spencer Oliver [email protected]
• Copyright c 2008-2010 Oyvind Harboe [email protected]
• Copyright c 2008 Duane Ellis [email protected]
• Copyright c 2009-2010 David Brownell
• Copyright Permission is granted to copy, distribute and/or modify this document under
the terms of the GNU Free Documentation License, Version 1.2 or any later
version published by the Free Software Foundation; with no Invariant Sections,
with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license
is included in the section entitled “GNU Free Documentation License”.
i
Short Contents
About . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1 OpenOCD Developer Resources . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Debug Adapter Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 About Jim-Tcl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4 Running . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5 OpenOCD Project Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6 Config File Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
7 Daemon Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
8 Debug Adapter Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . 38
9 Reset Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
10 TAP Declaration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
11 CPU Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
12 Flash Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
13 NAND Flash Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
14 PLD/FPGA Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
15 General Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
16 Architecture and Core Commands . . . . . . . . . . . . . . . . . . . . . . . 96
17 JTAG Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
18 Boundary Scan Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
19 TFTP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
20 GDB and OpenOCD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
21 Tcl Scripting API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
22 FAQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
23 Tcl Crash Course . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
A The GNU Free Documentation License. . . . . . . . . . . . . . . . . . 131
OpenOCD Concept Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Command and Driver Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
ii
Table of Contents
About . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
What is OpenOCD? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OpenOCD Web Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Latest User’s Guide: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OpenOCD User’s Forum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OpenOCD User’s Mailing List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OpenOCD IRC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1
OpenOCD Developer Resources . . . . . . . . . . . . . . . 3
1.1
1.2
1.3
1.4
2
1
2
2
2
2
2
OpenOCD GIT Repository . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Doxygen Developer Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OpenOCD Developer Mailing List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OpenOCD Bug Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3
3
3
4
Debug Adapter Hardware. . . . . . . . . . . . . . . . . . . . . . 5
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
Choosing a Dongle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stand alone Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
USB FT2232 Based . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
USB-JTAG / Altera USB-Blaster compatibles . . . . . . . . . . . . . . . . . .
USB JLINK based . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
USB RLINK based . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
USB ST-LINK based . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
USB Other . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IBM PC Parallel Printer Port Based . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
5
5
5
6
7
7
7
8
8
9
3
About Jim-Tcl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4
Running . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1
4.2
5
Simple setup, no customization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
What OpenOCD does as it starts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
OpenOCD Project Setup . . . . . . . . . . . . . . . . . . . . . 13
5.1
5.2
5.3
5.4
5.5
5.6
5.7
Hooking up the JTAG Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Project Directory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuration Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
User Config Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Project-Specific Utilities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Target Software Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Target Hardware Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13
14
14
14
16
17
18
iii
6
Config File Guidelines . . . . . . . . . . . . . . . . . . . . . . . . 20
6.1
6.2
Interface Config Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Board Config Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2.1 Communication Between Config files. . . . . . . . . . . . . . . . . . . . . .
6.2.2 Variable Naming Convention . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2.3 The reset-init Event Handler . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2.4 JTAG Clock Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.2.5 The init board procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3 Target Config Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.1 Default Value Boiler Plate Code . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.2 Adding TAPs to the Scan Chain . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.3 Add CPU targets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.4 Define CPU targets working in SMP . . . . . . . . . . . . . . . . . . . . . .
6.3.5 Chip Reset Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.6 The init targets procedure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.7 ARM Core Specific Hacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.3.8 Internal Flash Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6.4 Translating Configuration Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
Daemon Configuration . . . . . . . . . . . . . . . . . . . . . . . . 34
7.1
7.2
7.3
7.4
7.5
8
Configuration Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Entering the Run Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TCP/IP Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GDB Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Event Polling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
34
35
35
36
Debug Adapter Configuration . . . . . . . . . . . . . . . . 38
8.1
8.2
8.3
Interface Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interface Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transport Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.3.1 JTAG Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.3.2 SWD Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.3.3 SPI Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8.4 JTAG Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
24
24
24
25
26
26
27
27
28
29
29
29
30
31
32
32
32
38
39
46
46
46
46
46
Reset Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
9.1
9.2
9.3
9.4
Types of Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SRST and TRST Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Commands for Handling Resets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Custom Reset Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
48
48
49
51
iv
10
TAP Declaration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
10.1
10.2
10.3
10.4
10.5
10.6
10.7
11
Target List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Target CPU Types and Variants . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Target Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other $target name Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Target Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
NAND Configuration Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Erasing, Reading, Writing to NAND Flash . . . . . . . . . . . . . . . . . . .
Other NAND commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
NAND Driver List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
82
83
85
86
PLD/FPGA Commands . . . . . . . . . . . . . . . . . . . . . 89
14.1
14.2
15
68
69
71
71
71
72
79
80
80
81
NAND Flash Commands . . . . . . . . . . . . . . . . . . . . 82
13.1
13.2
13.3
13.4
14
59
60
61
63
65
Flash Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
12.1 Flash Configuration Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.2 Erasing, Reading, Writing to Flash . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.3 Other Flash commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.4 Flash Driver List. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.4.1 External Flash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.4.2 Internal Flash (Microcontrollers) . . . . . . . . . . . . . . . . . . . . . . . .
12.4.3 str9xpec driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.5 mFlash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.5.1 mFlash Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
12.5.2 mFlash commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13
53
54
54
56
56
57
58
CPU Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . 59
11.1
11.2
11.3
11.4
11.5
12
Scan Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TAP Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TAP Declaration Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Other TAP commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TAP Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Enabling and Disabling TAPs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Autoprobing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PLD/FPGA Configuration and Commands . . . . . . . . . . . . . . . . . . . 89
PLD/FPGA Drivers, Options, and Commands . . . . . . . . . . . . . . . 89
General Commands . . . . . . . . . . . . . . . . . . . . . . . . . . 90
15.1
15.2
15.3
15.4
15.5
15.6
15.7
Daemon Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Target State handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I/O Utilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Memory access commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Image loading commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Breakpoint and Watchpoint commands . . . . . . . . . . . . . . . . . . . . . . .
Misc Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
90
91
92
93
94
95
95
v
16
Architecture and Core Commands . . . . . . . . . 96
16.1 ARM Hardware Tracing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
16.1.1 ETM Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
16.1.2 ETM Trace Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
16.1.3 Trace Port Drivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
16.2 Generic ARM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
16.3 ARMv4 and ARMv5 Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
16.3.1 ARM7 and ARM9 specific commands . . . . . . . . . . . . . . . . . . 101
16.3.2 ARM720T specific commands . . . . . . . . . . . . . . . . . . . . . . . . . . 101
16.3.3 ARM9 specific commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
16.3.4 ARM920T specific commands . . . . . . . . . . . . . . . . . . . . . . . . . . 102
16.3.5 ARM926ej-s specific commands . . . . . . . . . . . . . . . . . . . . . . . . 102
16.3.6 ARM966E specific commands . . . . . . . . . . . . . . . . . . . . . . . . . . 102
16.3.7 XScale specific commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
16.4 ARMv6 Architecture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
16.4.1 ARM11 specific commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
16.5 ARMv7 Architecture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
16.5.1 ARMv7 Debug Access Port (DAP) specific commands . . 106
16.5.2 Cortex-M3 specific commands . . . . . . . . . . . . . . . . . . . . . . . . . . 106
16.6 Software Debug Messages and Tracing . . . . . . . . . . . . . . . . . . . . . . 107
17
JTAG Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
17.1
17.2
18
Low Level JTAG Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
TAP state names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Boundary Scan Commands . . . . . . . . . . . . . . . . 112
18.1
18.2
SVF: Serial Vector Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
XSVF: Xilinx Serial Vector Format. . . . . . . . . . . . . . . . . . . . . . . . . . 112
19
TFTP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
20
GDB and OpenOCD. . . . . . . . . . . . . . . . . . . . . . . . 114
20.1
20.2
20.3
20.4
20.5
21
114
114
115
115
116
Tcl Scripting API . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
21.1
21.2
21.3
22
Connecting to GDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sample GDB session startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring GDB for OpenOCD . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming using GDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using openocd SMP with GDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
API rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Internal low-level Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
OpenOCD specific Global Variables . . . . . . . . . . . . . . . . . . . . . . . . . 119
FAQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
vi
23
Tcl Crash Course . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
23.1 Tcl Rule #1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.2 Tcl Rule #1b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.3 Per Rule #1 - All Results are strings . . . . . . . . . . . . . . . . . . . . . . . .
23.4 Tcl Quoting Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.5 Consequences of Rule 1/2/3/4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.5.1 Tokenisation & Execution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.5.2 Command Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.5.3 The FOR command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.5.4 FOR command implementation . . . . . . . . . . . . . . . . . . . . . . . .
23.6 OpenOCD Tcl Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.6.1 source and find commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.6.2 format command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.6.3 Body or Inlined Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.6.4 Global Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23.7 Other Tcl Hacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
125
125
125
125
126
126
126
127
127
128
128
129
129
130
130
Appendix A The GNU Free Documentation
License. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
ADDENDUM: How to use this License for your documents . . . . . . . . 137
OpenOCD Concept Index . . . . . . . . . . . . . . . . . . . . . . . 138
Command and Driver Index . . . . . . . . . . . . . . . . . . . . 140
About
1
About
OpenOCD was created by Dominic Rath as part of a diploma thesis written at the University
of Applied Sciences Augsburg (http://www.fh-augsburg.de). Since that time, the project
has grown into an active open-source project, supported by a diverse community of software
and hardware developers from around the world.
What is OpenOCD?
The Open On-Chip Debugger (OpenOCD) aims to provide debugging, in-system programming and boundary-scan testing for embedded target devices.
It does so with the assistance of a debug adapter, which is a small hardware module which
helps provide the right kind of electrical signaling to the target being debugged. These are
required since the debug host (on which OpenOCD runs) won’t usually have native support
for such signaling, or the connector needed to hook up to the target.
Such debug adapters support one or more transport protocols, each of which involves different electrical signaling (and uses different messaging protocols on top of that signaling).
There are many types of debug adapter, and little uniformity in what they are called.
(There are also product naming differences.)
These adapters are sometimes packaged as discrete dongles, which may generically be called
hardware interface dongles. Some development boards also integrate them directly, which
may let the development board can be directly connected to the debug host over USB (and
sometimes also to power it over USB).
For example, a JTAG Adapter supports JTAG signaling, and is used to communicate with
JTAG (IEEE 1149.1) compliant TAPs on your target board. A TAP is a “Test Access Port”,
a module which processes special instructions and data. TAPs are daisy-chained within and
between chips and boards. JTAG supports debugging and boundary scan operations.
There are also SWD Adapters that support Serial Wire Debug (SWD) signaling to communicate with some newer ARM cores, as well as debug adapters which support both JTAG
and SWD transports. SWD only supports debugging, whereas JTAG also supports boundary scan operations.
For some chips, there are also Programming Adapters supporting special transports used
only to write code to flash memory, without support for on-chip debugging or boundary
scan. (At this writing, OpenOCD does not support such non-debug adapters.)
Dongles: OpenOCD currently supports many types of hardware dongles: USB based, parallel port based, and other standalone boxes that run OpenOCD internally. See Chapter 2
[Debug Adapter Hardware], page 5.
GDB Debug: It allows ARM7 (ARM7TDMI and ARM720t), ARM9 (ARM920T,
ARM922T, ARM926EJ–S, ARM966E–S), XScale (PXA25x, IXP42x) and Cortex-M3
(Stellaris LM3 and ST STM32) based cores to be debugged via the GDB protocol.
Flash Programing: Flash writing is supported for external CFI compatible NOR flashes
(Intel and AMD/Spansion command set) and several internal flashes (LPC1700, LPC2000,
AT91SAM7, AT91SAM3U, STR7x, STR9x, LM3, and STM32x). Preliminary support for
various NAND flash controllers (LPC3180, Orion, S3C24xx, more) controller is included.
About
2
OpenOCD Web Site
The OpenOCD web site provides the latest public news from the community:
http://openocd.sourceforge.net/
Latest User’s Guide:
The user’s guide you are now reading may not be the latest one available. A version for
more recent code may be available. Its HTML form is published regularly at:
http://openocd.sourceforge.net/doc/html/index.html
PDF form is likewise published at:
http://openocd.sourceforge.net/doc/pdf/openocd.pdf
OpenOCD User’s Forum
There is an OpenOCD forum (phpBB) hosted by SparkFun, which might be helpful to you.
Note that if you want anything to come to the attention of developers, you should post it
to the OpenOCD Developer Mailing List instead of this forum.
http://forum.sparkfun.com/viewforum.php?f=18
OpenOCD User’s Mailing List
The OpenOCD User Mailing List provides the primary means of communication between
users:
https://lists.sourceforge.net/mailman/listinfo/openocd-user
OpenOCD IRC
Support can also be found on irc: irc://irc.freenode.net/openocd
Chapter 1: OpenOCD Developer Resources
3
1 OpenOCD Developer Resources
If you are interested in improving the state of OpenOCD’s debugging and testing support,
new contributions will be welcome. Motivated developers can produce new target, flash or
interface drivers, improve the documentation, as well as more conventional bug fixes and
enhancements.
The resources in this chapter are available for developers wishing to explore or expand the
OpenOCD source code.
1.1 OpenOCD GIT Repository
During the 0.3.x release cycle, OpenOCD switched from Subversion to a GIT repository
hosted at SourceForge. The repository URL is:
git://openocd.git.sourceforge.net/gitroot/openocd/openocd
You may prefer to use a mirror and the HTTP protocol:
http://repo.or.cz/r/openocd.git
With standard GIT tools, use git clone to initialize a local repository, and git pull to
update it. There are also gitweb pages letting you browse the repository with a web browser,
or download arbitrary snapshots without needing a GIT client:
http://openocd.git.sourceforge.net/git/gitweb.cgi?p=openocd/openocd
http://repo.or.cz/w/openocd.git
The ‘README’ file contains the instructions for building the project from the repository or a
snapshot.
Developers that want to contribute patches to the OpenOCD system are strongly encouraged to work against mainline. Patches created against older versions may require additional
work from their submitter in order to be updated for newer releases.
1.2 Doxygen Developer Manual
During the 0.2.x release cycle, the OpenOCD project began providing a Doxygen reference
manual. This document contains more technical information about the software internals,
development processes, and similar documentation:
http://openocd.sourceforge.net/doc/doxygen/html/index.html
This document is a work-in-progress, but contributions would be welcome to fill in the gaps.
All of the source files are provided in-tree, listed in the Doxyfile configuration in the top of
the source tree.
1.3 OpenOCD Developer Mailing List
The OpenOCD Developer Mailing List provides the primary means of communication between developers:
https://lists.sourceforge.net/mailman/listinfo/openocd-devel
Discuss and submit patches to this list. The ‘HACKING’ file contains basic information about
how to prepare patches.
Chapter 1: OpenOCD Developer Resources
4
1.4 OpenOCD Bug Database
During the 0.4.x release cycle the OpenOCD project team began using Trac for its bug
database:
https://sourceforge.net/apps/trac/openocd
Chapter 2: Debug Adapter Hardware
5
2 Debug Adapter Hardware
Defined: dongle: A small device that plugins into a computer and serves as an adapter ....
[snip]
In the OpenOCD case, this generally refers to a small adapter that attaches to your computer via USB or the Parallel Printer Port. One exception is the Zylin ZY1000, packaged
as a small box you attach via an ethernet cable. The Zylin ZY1000 has the advantage that
it does not require any drivers to be installed on the developer PC. It also has a built in
web interface. It supports RTCK/RCLK or adaptive clocking and has a built in relay to
power cycle targets remotely.
2.1 Choosing a Dongle
There are several things you should keep in mind when choosing a dongle.
1. Transport Does it support the kind of communication that you need? OpenOCD
focusses mostly on JTAG. Your version may also support other ways to communicate
with target devices.
2. Voltage What voltage is your target - 1.8, 2.8, 3.3, or 5V? Does your dongle support
it? You might need a level converter.
3. Pinout What pinout does your target board use? Does your dongle support it? You
may be able to use jumper wires, or an "octopus" connector, to convert pinouts.
4. Connection Does your computer have the USB, printer, or Ethernet port needed?
5. RTCK Do you expect to use it with ARM chips and boards with RTCK support? Also
known as “adaptive clocking”
2.2 Stand alone Systems
ZY1000 See: http: / / www . ultsol . com / index . php / component / content / article /
8/33-zylin-zy1000-jtag-probe Technically, not a dongle, but a standalone box. The
ZY1000 has the advantage that it does not require any drivers installed on the developer
PC. It also has a built in web interface. It supports RTCK/RCLK or adaptive clocking and
has a built in relay to power cycle targets remotely.
2.3 USB FT2232 Based
There are many USB JTAG dongles on the market, many of them are based on a chip from
“Future Technology Devices International” (FTDI) known as the FTDI FT2232; this is a
USB full speed (12 Mbps) chip. See: http://www.ftdichip.com for more information.
In summer 2009, USB high speed (480 Mbps) versions of these FTDI chips are starting to
become available in JTAG adapters. (Adapters using those high speed FT2232H chips may
support adaptive clocking.)
The FT2232 chips are flexible enough to support some other transport options, such as
SWD or the SPI variants used to program some chips. They have two communications
channels, and one can be used for a UART adapter at the same time the other one is used
to provide a debug adapter.
Also, some development boards integrate an FT2232 chip to serve as a built-in low cost
debug adapter and usb-to-serial solution.
Chapter 2: Debug Adapter Hardware
6
• usbjtag
Link http: / /elk .informatik .fh-augsburg .de /hhweb /doc /openocd /usbjtag /
usbjtag.html
• jtagkey
See: http://www.amontec.com/jtagkey.shtml
• jtagkey2
See: http://www.amontec.com/jtagkey2.shtml
• oocdlink
See: http://www.oocdlink.com By Joern Kaipf
• signalyzer
See: http://www.signalyzer.com
• Stellaris Eval Boards
See: http://www.luminarymicro.com - The Stellaris eval boards bundle FT2232based JTAG and SWD support, which can be used to debug the Stellaris chips. Using
separate JTAG adapters is optional. These boards can also be used in a "pass through"
mode as JTAG adapters to other target boards, disabling the Stellaris chip.
• Luminary ICDI
See: http://www.luminarymicro.com - Luminary In-Circuit Debug Interface (ICDI)
Boards are included in Stellaris LM3S9B9x Evaluation Kits. Like the non-detachable
FT2232 support on the other Stellaris eval boards, they can be used to debug other
target boards.
• olimex-jtag
See: http://www.olimex.com
• Flyswatter/Flyswatter2
See: http://www.tincantools.com
• turtelizer2
See: Turtelizer 2, or http://www.ethernut.de
• comstick
Link: http://www.hitex.com/index.php?id=383
• stm32stick
Link http://www.hitex.com/stm32-stick
• axm0432 jtag
Axiom AXM-0432 Link http://www.axman.com - NOTE: This JTAG does not appear
to be available anymore as of April 2012.
• cortino
Link http://www.hitex.com/index.php?id=cortino
• dlp-usb1232h
Link http://www.dlpdesign.com/usb/usb1232h.shtml
• digilent-hs1
Link http://www.digilentinc.com/Products/Detail.cfm?Prod=JTAG-HS1
2.4 USB-JTAG / Altera USB-Blaster compatibles
These devices also show up as FTDI devices, but are not protocol-compatible with the
FT2232 devices. They are, however, protocol-compatible among themselves. USB-JTAG
Chapter 2: Debug Adapter Hardware
7
devices typically consist of a FT245 followed by a CPLD that understands a particular
protocol, or emulate this protocol using some other hardware.
They may appear under different USB VID/PID depending on the particular product.
The driver can be configured to search for any VID/PID pair (see the section on driver
commands).
• USB-JTAG Kolja Waschk’s USB Blaster-compatible adapter
Link: http://ixo-jtag.sourceforge.net/
• Altera USB-Blaster
Link: http://www.altera.com/literature/ug/ug_usb_blstr.pdf
2.5 USB JLINK based
There are several OEM versions of the Segger JLINK adapter. It is an example of a micro
controller based JTAG adapter, it uses an AT91SAM764 internally.
• ATMEL SAMICE Only works with ATMEL chips!
Link: http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3892
• SEGGER JLINK
Link: http://www.segger.com/jlink.html
• IAR J-Link
Link: http://www.iar.com/en/products/hardware-debug-probes/iar-j-link/
2.6 USB RLINK based
Raisonance has an adapter called RLink. It exists in a stripped-down form on the STM32
Primer, permanently attached to the JTAG lines. It also exists on the STM32 Primer2, but
that is wired for SWD and not JTAG, thus not supported.
• Raisonance RLink
Link: http://www.mcu-raisonance.com/~rlink-debugger-programmer__microcontrollers__tool~to
html
• STM32 Primer
Link: http://www.stm32circle.com/resources/stm32primer.php
• STM32 Primer2
Link: http://www.stm32circle.com/resources/stm32primer2.php
2.7 USB ST-LINK based
ST Micro has an adapter called ST-LINK. They only work with ST Micro chips, notably
STM32 and STM8.
• ST-LINK
This is available standalone and as part of some kits, eg. STM32VLDISCOVERY.
Link: http://www.st.com/internet/evalboard/product/219866.jsp
• ST-LINK/V2
This is available standalone and as part of some kits, eg. STM32F4DISCOVERY.
Link: http://www.st.com/internet/evalboard/product/251168.jsp
Chapter 2: Debug Adapter Hardware
8
For info the original ST-LINK enumerates using the mass storage usb class, however it’s
implementation is completely broken. The result is this causes issues under linux. The
simplest solution is to get linux to ignore the ST-LINK using one of the following methods:
• modprobe -r usb-storage && modprobe usb-storage quirks=483:3744:i
• add "options usb-storage quirks=483:3744:i" to /etc/modprobe.conf
2.8 USB Other
• USBprog
Link: http://shop.embedded-projects.net/ - which uses an Atmel MEGA32 and a
UBN9604
• USB - Presto
Link: http://tools.asix.net/prg_presto.htm
• Versaloon-Link
Link: http://www.versaloon.com
• ARM-JTAG-EW
Link: http://www.olimex.com/dev/arm-jtag-ew.html
• Buspirate
Link: http://dangerousprototypes.com/bus-pirate-manual/
• opendous
Link: http://code.google.com/p/opendous-jtag/
• estick
Link: http://code.google.com/p/estick-jtag/
• Keil ULINK v1
Link: http://www.keil.com/ulink1/
2.9 IBM PC Parallel Printer Port Based
The two well known “JTAG Parallel Ports” cables are the Xilnx DLC5 and the Macraigor
Wiggler. There are many clones and variations of these on the market.
Note that parallel ports are becoming much less common, so if you have the choice you
should probably avoid these adapters in favor of USB-based ones.
• Wiggler - There are many clones of this.
Link: http://www.macraigor.com/wiggler.htm
• DLC5 - From XILINX - There are many clones of this
Link: Search the web for: “XILINX DLC5” - it is no longer produced, PDF schematics
are easily found and it is easy to make.
• Amontec - JTAG Accelerator
Link: http://www.amontec.com/jtag_accelerator.shtml
• GW16402
Link: http://www.gateworks.com/products/avila_accessories/gw16042.php
• Wiggler2
Link: http: / / www . ccac . rwth-aachen . de / ~michaels / index . php / hardware /
armjtag
Chapter 2: Debug Adapter Hardware
9
• Wiggler ntrst inverted
Yet another variation - See the source code, src/jtag/parport.c
• old amt wiggler
Unknown - probably not on the market today
• arm-jtag
Link: Most likely http://www.olimex.com/dev/arm-jtag.html [another wiggler
clone]
• chameleon
Link: http://www.amontec.com/chameleon.shtml
• Triton
Unknown.
• Lattice
ispDownload from Lattice Semiconductor http://www.latticesemi.com/lit/docs/
devtools/dlcable.pdf
• flashlink
From ST Microsystems;
Link:
http: / / www . st . com / internet / com / TECHNICAL_RESOURCES /
TECHNICAL_LITERATURE/DATA_BRIEF/DM00039500.pdf
2.10 Other...
• ep93xx
An EP93xx based Linux machine using the GPIO pins directly.
• at91rm9200
Like the EP93xx - but an ATMEL AT91RM9200 based solution using the GPIO pins
on the chip.
Chapter 3: About Jim-Tcl
10
3 About Jim-Tcl
OpenOCD uses a small “Tcl Interpreter” known as Jim-Tcl. This programming language
provides a simple and extensible command interpreter.
All commands presented in this Guide are extensions to Jim-Tcl. You can use them as
simple commands, without needing to learn much of anything about Tcl. Alternatively,
can write Tcl programs with them.
You can learn more about Jim at its website, http: / /jim .berlios .de. There is an
active and responsive community, get on the mailing list if you have any questions. Jim-Tcl
maintainers also lurk on the OpenOCD mailing list.
• Jim vs. Tcl
Jim-Tcl is a stripped down version of the well known Tcl language, which can be found
here: http://www.tcl.tk. Jim-Tcl has far fewer features. Jim-Tcl is several dozens
of .C files and .H files and implements the basic Tcl command set. In contrast: Tcl 8.6
is a 4.2 MB .zip file containing 1540 files.
• Missing Features
Our practice has been: Add/clone the real Tcl feature if/when needed. We welcome
Jim-Tcl improvements, not bloat. Also there are a large number of optional Jim-Tcl
features that are not enabled in OpenOCD.
• Scripts
OpenOCD configuration scripts are Jim-Tcl Scripts. OpenOCD’s command interpreter
today is a mixture of (newer) Jim-Tcl commands, and (older) the orginal command
interpreter.
• Commands
At the OpenOCD telnet command line (or via the GDB monitor command) one can
type a Tcl for() loop, set variables, etc. Some of the commands documented in this
guide are implemented as Tcl scripts, from a ‘startup.tcl’ file internal to the server.
• Historical Note
Jim-Tcl was introduced to OpenOCD in spring 2008. Fall 2010, before OpenOCD
0.5 release OpenOCD switched to using Jim Tcl as a git submodule, which greatly
simplified upgrading Jim Tcl to benefit from new features and bugfixes in Jim Tcl.
• Need a crash course in Tcl?
See Chapter 23 [Tcl Crash Course], page 125.
Chapter 4: Running
11
4 Running
Properly installing OpenOCD sets up your operating system to grant it access to the debug
adapters. On Linux, this usually involves installing a file in ‘/etc/udev/rules.d,’ so
OpenOCD has permissions. MS-Windows needs complex and confusing driver configuration
for every peripheral. Such issues are unique to each operating system, and are not detailed
in this User’s Guide.
Then later you will invoke the OpenOCD server, with various options to tell it how each
debug session should work. The ‘--help’ option shows:
bash$ openocd --help
--help
| -h
display this help
--version
| -v
display OpenOCD version
--file
| -f
use configuration file <name>
--search
| -s
dir to search for config files and scripts
--debug
| -d
set debug level <0-3>
--log_output | -l
redirect log output to file <name>
--command
| -c
run <command>
If you don’t give any ‘-f’ or ‘-c’ options, OpenOCD tries to read the configuration file
‘openocd.cfg’. To specify one or more different configuration files, use ‘-f’ options. For
example:
openocd -f config1.cfg -f config2.cfg -f config3.cfg
Configuration files and scripts are searched for in
1. the current directory,
2. any search dir specified on the command line using the ‘-s’ option,
3. any search dir specified using the add_script_search_dir command,
4. ‘$HOME/.openocd’ (not on Windows),
5. the site wide script library ‘$pkgdatadir/site’ and
6. the OpenOCD-supplied script library ‘$pkgdatadir/scripts’.
The first found file with a matching file name will be used.
Note: Don’t try to use configuration script names or paths which include the
"#" character. That character begins Tcl comments.
4.1 Simple setup, no customization
In the best case, you can use two scripts from one of the script libraries, hook up your JTAG
adapter, and start the server ... and your JTAG setup will just work "out of the box".
Always try to start by reusing those scripts, but assume you’ll need more customization
even if this works. See Chapter 5 [OpenOCD Project Setup], page 13.
If you find a script for your JTAG adapter, and for your board or target, you may be able
to hook up your JTAG adapter then start the server like:
openocd -f interface/ADAPTER.cfg -f board/MYBOARD.cfg
You might also need to configure which reset signals are present, using ‘-c ’reset_config
trst_and_srst’’ or something similar. If all goes well you’ll see output something like
Chapter 4: Running
12
Open On-Chip Debugger 0.4.0 (2010-01-14-15:06)
For bug reports, read
http://openocd.sourceforge.net/doc/doxygen/bugs.html
Info : JTAG tap: lm3s.cpu tap/device found: 0x3ba00477
(mfg: 0x23b, part: 0xba00, ver: 0x3)
Seeing that "tap/device found" message, and no warnings, means the JTAG communication
is working. That’s a key milestone, but you’ll probably need more project-specific setup.
4.2 What OpenOCD does as it starts
OpenOCD starts by processing the configuration commands provided on the command line
or, if there were no ‘-c command’ or ‘-f file.cfg’ options given, in ‘openocd.cfg’. See
[Configuration Stage], page 34. At the end of the configuration stage it verifies the JTAG
scan chain defined using those commands; your configuration should ensure that this always
succeeds. Normally, OpenOCD then starts running as a daemon. Alternatively, commands
may be used to terminate the configuration stage early, perform work (such as updating
some flash memory), and then shut down without acting as a daemon.
Once OpenOCD starts running as a daemon, it waits for connections from clients (Telnet,
GDB, Other) and processes the commands issued through those channels.
If you are having problems, you can enable internal debug messages via the ‘-d’ option.
Also it is possible to interleave Jim-Tcl commands w/config scripts using the ‘-c’ command
line switch.
To enable debug output (when reporting problems or working on OpenOCD itself), use
the ‘-d’ command line switch. This sets the ‘debug_level’ to "3", outputting the most
information, including debug messages. The default setting is "2", outputting only informational messages, warnings and errors. You can also change this setting from within a
telnet or gdb session using debug_level <n> (see [debug level], page 90).
You can redirect all output from the daemon to a file using the ‘-l <logfile>’ switch.
Note! OpenOCD will launch the GDB & telnet server even if it can not establish a connection with the target. In general, it is possible for the JTAG controller to be unresponsive
until the target is set up correctly via e.g. GDB monitor commands in a GDB init script.
Chapter 5: OpenOCD Project Setup
13
5 OpenOCD Project Setup
To use OpenOCD with your development projects, you need to do more than just connecting
the JTAG adapter hardware (dongle) to your development board and then starting the
OpenOCD server. You also need to configure that server so that it knows about that
adapter and board, and helps your work. You may also want to connect OpenOCD to
GDB, possibly using Eclipse or some other GUI.
5.1 Hooking up the JTAG Adapter
Today’s most common case is a dongle with a JTAG cable on one side (such as a ribbon
cable with a 10-pin or 20-pin IDC connector) and a USB cable on the other. Instead of
USB, some cables use Ethernet; older ones may use a PC parallel port, or even a serial port.
1. Start with power to your target board turned off, and nothing connected to your JTAG
adapter. If you’re particularly paranoid, unplug power to the board. It’s important to
have the ground signal properly set up, unless you are using a JTAG adapter which
provides galvanic isolation between the target board and the debugging host.
2. Be sure it’s the right kind of JTAG connector. If your dongle has a 20-pin ARM
connector, you need some kind of adapter (or octopus, see below) to hook it up to
boards using 14-pin or 10-pin connectors ... or to 20-pin connectors which don’t use
ARM’s pinout.
In the same vein, make sure the voltage levels are compatible. Not all JTAG adapters
have the level shifters needed to work with 1.2 Volt boards.
3. Be certain the cable is properly oriented or you might damage your board. In most
cases there are only two possible ways to connect the cable. Connect the JTAG cable
from your adapter to the board. Be sure it’s firmly connected.
In the best case, the connector is keyed to physically prevent you from inserting it
wrong. This is most often done using a slot on the board’s male connector housing,
which must match a key on the JTAG cable’s female connector. If there’s no housing,
then you must look carefully and make sure pin 1 on the cable hooks up to pin 1 on
the board. Ribbon cables are frequently all grey except for a wire on one edge, which
is red. The red wire is pin 1.
Sometimes dongles provide cables where one end is an “octopus” of color coded singlewire connectors, instead of a connector block. These are great when converting from
one JTAG pinout to another, but are tedious to set up. Use these with connector
pinout diagrams to help you match up the adapter signals to the right board pins.
4. Connect the adapter’s other end once the JTAG cable is connected. A USB, parallel,
or serial port connector will go to the host which you are using to run OpenOCD. For
Ethernet, consult the documentation and your network administrator.
For USB based JTAG adapters you have an easy sanity check at this point: does the
host operating system see the JTAG adapter? If that host is an MS-Windows host,
you’ll need to install a driver before OpenOCD works.
5. Connect the adapter’s power supply, if needed. This step is primarily for non-USB
adapters, but sometimes USB adapters need extra power.
6. Power up the target board. Unless you just let the magic smoke escape, you’re now
ready to set up the OpenOCD server so you can use JTAG to work with that board.
Chapter 5: OpenOCD Project Setup
14
Talk with the OpenOCD server using telnet (telnet localhost 4444 on many systems) or
GDB. See Chapter 20 [GDB and OpenOCD], page 114.
5.2 Project Directory
There are many ways you can configure OpenOCD and start it up.
A simple way to organize them all involves keeping a single directory for your work with
a given board. When you start OpenOCD from that directory, it searches there first for
configuration files, scripts, files accessed through semihosting, and for code you upload to
the target board. It is also the natural place to write files, such as log files and data you
download from the board.
5.3 Configuration Basics
There are two basic ways of configuring OpenOCD, and a variety of ways you can mix them.
Think of the difference as just being how you start the server:
• Many ‘-f file’ or ‘-c command’ options on the command line
• No options, but a user config file in the current directory named ‘openocd.cfg’
Here is an example ‘openocd.cfg’ file for a setup using a Signalyzer FT2232-based JTAG
adapter to talk to a board with an Atmel AT91SAM7X256 microcontroller:
source [find interface/signalyzer.cfg]
# GDB can also flash my flash!
gdb_memory_map enable
gdb_flash_program enable
source [find target/sam7x256.cfg]
Here is the command line equivalent of that configuration:
openocd -f interface/signalyzer.cfg \
-c "gdb_memory_map enable" \
-c "gdb_flash_program enable" \
-f target/sam7x256.cfg
You could wrap such long command lines in shell scripts, each supporting a different development task. One might re-flash the board with a specific firmware version. Another might
set up a particular debugging or run-time environment.
Important: At this writing (October 2009) the command line method has problems with how it treats variables. For example, after ‘-c "set VAR value"’, or
doing the same in a script, the variable VAR will have no value that can be
tested in a later script.
Here we will focus on the simpler solution: one user config file, including basic configuration
plus any TCL procedures to simplify your work.
5.4 User Config Files
A user configuration file ties together all the parts of a project in one place. One of the
following will match your situation best:
Chapter 5: OpenOCD Project Setup
15
• Ideally almost everything comes from configuration files provided by someone
else.
For example, OpenOCD distributes a ‘scripts’ directory (probably in
‘/usr/share/openocd/scripts’ on Linux). Board and tool vendors can provide these
too, as can individual user sites; the ‘-s’ command line option lets you say where to
find these files. (See Chapter 4 [Running], page 11.) The AT91SAM7X256 example
above works this way.
Three main types of non-user configuration file each have their own subdirectory in the
‘scripts’ directory:
1. interface – one for each different debug adapter;
2. board – one for each different board
3. target – the chips which integrate CPUs and other JTAG TAPs
Best case: include just two files, and they handle everything else. The first is an
interface config file. The second is board-specific, and it sets up the JTAG TAPs and
their GDB targets (by deferring to some ‘target.cfg’ file), declares all flash memory,
and leaves you nothing to do except meet your deadline:
source [find interface/olimex-jtag-tiny.cfg]
source [find board/csb337.cfg]
Boards with a single microcontroller often won’t need more than the target config file,
as in the AT91SAM7X256 example. That’s because there is no external memory (flash,
DDR RAM), and the board differences are encapsulated by application code.
• Maybe you don’t know yet what your board looks like to JTAG. Once you know the
‘interface.cfg’ file to use, you may need help from OpenOCD to discover what’s
on the board. Once you find the JTAG TAPs, you can just search for appropriate
target and board configuration files ... or write your own, from the bottom up. See
[Autoprobing], page 57.
• You can often reuse some standard config files but need to write a few new ones,
probably a ‘board.cfg’ file. You will be using commands described later in this User’s
Guide, and working with the guidelines in the next chapter.
For example, there may be configuration files for your JTAG adapter and target chip,
but you need a new board-specific config file giving access to your particular flash chips.
Or you might need to write another target chip configuration file for a new chip built
around the Cortex M3 core.
Note: When you write new configuration files, please submit them for inclusion in the next OpenOCD release. For example, a ‘board/newboard.cfg’
file will help the next users of that board, and a ‘target/newcpu.cfg’ will
help support users of any board using that chip.
• You may may need to write some C code. It may be as simple as a supporting a
new ft2232 or parport based adapter; a bit more involved, like a NAND or NOR flash
controller driver; or a big piece of work like supporting a new chip architecture.
Reuse the existing config files when you can. Look first in the ‘scripts/boards’ area, then
‘scripts/targets’. You may find a board configuration that’s a good example to follow.
When you write config files, separate the reusable parts (things every user of that interface,
chip, or board needs) from ones specific to your environment and debugging approach.
Chapter 5: OpenOCD Project Setup
16
• For example, a gdb-attach event handler that invokes the reset init command will
interfere with debugging early boot code, which performs some of the same actions
that the reset-init event handler does.
• Likewise, the arm9 vector_catch command (or its siblings xscale vector_catch and
cortex_m3 vector_catch) can be a timesaver during some debug sessions, but don’t
make everyone use that either. Keep those kinds of debugging aids in your user config
file, along with messaging and tracing setup. (See [Software Debug Messages and
Tracing], page 107.)
• You might need to override some defaults. For example, you might need to move,
shrink, or back up the target’s work area if your application needs much SRAM.
• TCP/IP port configuration is another example of something which is environmentspecific, and should only appear in a user config file. See [TCP/IP Ports], page 35.
5.5 Project-Specific Utilities
A few project-specific utility routines may well speed up your work. Write them, and keep
them in your project’s user config file.
For example, if you are making a boot loader work on a board, it’s nice to be able to debug
the “after it’s loaded to RAM” parts separately from the finicky early code which sets up
the DDR RAM controller and clocks. A script like this one, or a more GDB-aware sibling,
may help:
proc ramboot { } {
# Reset, running the target’s "reset-init" scripts
# to initialize clocks and the DDR RAM controller.
# Leave the CPU halted.
reset init
# Load CONFIG_SKIP_LOWLEVEL_INIT version into DDR RAM.
load_image u-boot.bin 0x20000000
# Start running.
resume 0x20000000
}
Then once that code is working you will need to make it boot from NOR flash; a different
utility would help. Alternatively, some developers write to flash using GDB. (You might
use a similar script if you’re working with a flash based microcontroller application instead
of a boot loader.)
proc newboot { } {
# Reset, leaving the CPU halted. The "reset-init" event
# proc gives faster access to the CPU and to NOR flash;
# "reset halt" would be slower.
reset init
# Write standard version of U-Boot into the first two
# sectors of NOR flash ... the standard version should
# do the same lowlevel init as "reset-init".
Chapter 5: OpenOCD Project Setup
flash
flash
flash
flash
17
protect 0 0 1 off
erase_sector 0 0 1
write_bank 0 u-boot.bin 0x0
protect 0 0 1 on
# Reboot from scratch using that new boot loader.
reset run
}
You may need more complicated utility procedures when booting from NAND. That often
involves an extra bootloader stage, running from on-chip SRAM to perform DDR RAM
setup so it can load the main bootloader code (which won’t fit into that SRAM).
Other helper scripts might be used to write production system images, involving considerably more than just a three stage bootloader.
5.6 Target Software Changes
Sometimes you may want to make some small changes to the software you’re developing,
to help make JTAG debugging work better. For example, in C or assembly language code
you might use #ifdef JTAG_DEBUG (or its converse) around code handling issues like:
• Watchdog Timers... Watchog timers are typically used to automatically reset systems
if some application task doesn’t periodically reset the timer. (The assumption is that
the system has locked up if the task can’t run.) When a JTAG debugger halts the
system, that task won’t be able to run and reset the timer ... potentially causing resets
in the middle of your debug sessions.
It’s rarely a good idea to disable such watchdogs, since their usage needs to be debugged
just like all other parts of your firmware. That might however be your only option.
Look instead for chip-specific ways to stop the watchdog from counting while the system is in a debug halt state. It may be simplest to set that non-counting mode in your
debugger startup scripts. You may however need a different approach when, for example, a motor could be physically damaged by firmware remaining inactive in a debug
halt state. That might involve a type of firmware mode where that "non-counting"
mode is disabled at the beginning then re-enabled at the end; a watchdog reset might
fire and complicate the debug session, but hardware (or people) would be protected.1
• ARM Semihosting... When linked with a special runtime library provided with many
toolchains2 , your target code can use I/O facilities on the debug host. That library
provides a small set of system calls which are handled by OpenOCD. It can let the
debugger provide your system console and a file system, helping with early debugging
or providing a more capable environment for sometimes-complex tasks like installing
system firmware onto NAND or SPI flash.
1
2
Note that many systems support a "monitor mode" debug that is a somewhat cleaner way to address such
issues. You can think of it as only halting part of the system, maybe just one task, instead of the whole
thing. At this writing, January 2010, OpenOCD based debugging does not support monitor mode debug,
only "halt mode" debug.
See chapter 8 "Semihosting" in ARM DUI 0203I, the "RealView Compilation Tools Developer Guide". The
CodeSourcery EABI toolchain also includes a semihosting library.
Chapter 5: OpenOCD Project Setup
18
• ARM Wait-For-Interrupt... Many ARM chips synchronize the JTAG clock using the
core clock. Low power states which stop that core clock thus prevent JTAG access. Idle
loops in tasking environments often enter those low power states via the WFI instruction
(or its coprocessor equivalent, before ARMv7).
You may want to disable that instruction in source code, or otherwise prevent using that
state, to ensure you can get JTAG access at any time.3 For example, the OpenOCD
halt command may not work for an idle processor otherwise.
• Delay after reset... Not all chips have good support for debugger access right after
reset; many LPC2xxx chips have issues here. Similarly, applications that reconfigure
pins used for JTAG access as they start will also block debugger access.
To work with boards like this, enable a short delay loop the first thing after reset, before
"real" startup activities. For example, one second’s delay is usually more than enough
time for a JTAG debugger to attach, so that early code execution can be debugged or
firmware can be replaced.
• Debug Communications Channel (DCC)... Some processors include mechanisms to
send messages over JTAG. Many ARM cores support these, as do some cores from
other vendors. (OpenOCD may be able to use this DCC internally, speeding up some
operations like writing to memory.)
Your application may want to deliver various debugging messages over JTAG, by linking
with a small library of code provided with OpenOCD and using the utilities there to
send various kinds of message. See [Software Debug Messages and Tracing], page 107.
5.7 Target Hardware Setup
Chip vendors often provide software development boards which are highly configurable, so
that they can support all options that product boards may require. Make sure that any
jumpers or switches match the system configuration you are working with.
Common issues include:
• JTAG setup ... Boards may support more than one JTAG configuration. Examples
include jumpers controlling pullups versus pulldowns on the nTRST and/or nSRST
signals, and choice of connectors (e.g. which of two headers on the base board, or one
from a daughtercard). For some Texas Instruments boards, you may need to jumper
the EMU0 and EMU1 signals (which OpenOCD won’t currently control).
• Boot Modes ... Complex chips often support multiple boot modes, controlled by external jumpers. Make sure this is set up correctly. For example many i.MX boards from
NXP need to be jumpered to "ATX mode" to start booting using the on-chip ROM,
when using second stage bootloader code stored in a NAND flash chip.
Such explicit configuration is common, and not limited to booting from NAND. You
might also need to set jumpers to start booting using code loaded from an MMC/SD
card; external SPI flash; Ethernet, UART, or USB links; NOR flash; OneNAND flash;
some external host; or various other sources.
3
As a more polite alternative, some processors have special debug-oriented registers which can be used to
change various features including how the low power states are clocked while debugging. The STM32
DBGMCU CR register is an example; at the cost of extra power consumption, JTAG can be used during
low power states.
Chapter 5: OpenOCD Project Setup
19
• Memory Addressing ... Boards which support multiple boot modes may also have
jumpers to configure memory addressing. One board, for example, jumpers external
chipselect 0 (used for booting) to address either a large SRAM (which must be preloaded via JTAG), NOR flash, or NAND flash. When it’s jumpered to address NAND
flash, that board must also be told to start booting from on-chip ROM.
Your ‘board.cfg’ file may also need to be told this jumper configuration, so that it can
know whether to declare NOR flash using flash bank or instead declare NAND flash
with nand device; and likewise which probe to perform in its reset-init handler.
A closely related issue is bus width. Jumpers might need to distinguish between 8 bit
or 16 bit bus access for the flash used to start booting.
• Peripheral Access ... Development boards generally provide access to every peripheral on the chip, sometimes in multiple modes (such as by providing multiple audio
codec chips). This interacts with software configuration of pin multiplexing, where for
example a given pin may be routed either to the MMC/SD controller or the GPIO
controller. It also often interacts with configuration jumpers. One jumper may be used
to route signals to an MMC/SD card slot or an expansion bus (which might in turn
affect booting); others might control which audio or video codecs are used.
Plus you should of course have reset-init event handlers which set up the hardware to
match that jumper configuration. That includes in particular any oscillator or PLL used
to clock the CPU, and any memory controllers needed to access external memory and
peripherals. Without such handlers, you won’t be able to access those resources without
working target firmware which can do that setup ... this can be awkward when you’re
trying to debug that target firmware. Even if there’s a ROM bootloader which handles a
few issues, it rarely provides full access to all board-specific capabilities.
Chapter 6: Config File Guidelines
20
6 Config File Guidelines
This chapter is aimed at any user who needs to write a config file, including developers and
integrators of OpenOCD and any user who needs to get a new board working smoothly. It
provides guidelines for creating those files.
You should find the following directories under $(INSTALLDIR)/scripts, with files including the ones listed here. Use them as-is where you can; or as models for new files.
• ‘interface’ ... These are for debug adapters. Files that configure JTAG adapters go
here.
$ ls interface
altera-usb-blaster.cfg
hilscher_nxhx50_etm.cfg
openrd.cfg
arm-jtag-ew.cfg
hilscher_nxhx50_re.cfg
osbdm.cfg
arm-usb-ocd.cfg
hitex_str9-comstick.cfg
parport.cfg
at91rm9200.cfg
icebear.cfg
parport_dlc5.cfg
axm0432.cfg
jlink.cfg
redbee-econotag.cfg
busblaster.cfg
jtagkey2.cfg
redbee-usb.cfg
buspirate.cfg
jtagkey2p.cfg
rlink.cfg
calao-usb-a9260-c01.cfg
jtagkey.cfg
sheevaplug.cfg
calao-usb-a9260-c02.cfg
jtagkey-tiny.cfg
signalyzer.cfg
calao-usb-a9260.cfg
kt-link.cfg
signalyzer-h2.cfg
chameleon.cfg
lisa-l.cfg
signalyzer-h4.cfg
cortino.cfg
luminary.cfg
signalyzer-lite.cfg
digilent-hs1.cfg
luminary-icdi.cfg
stlink-v1.cfg
dlp-usb1232h.cfg
luminary-lm3s811.cfg
stlink-v2.cfg
dummy.cfg
minimodule.cfg
stm32-stick.cfg
estick.cfg
neodb.cfg
turtelizer2.cfg
flashlink.cfg
ngxtech.cfg
ulink.cfg
flossjtag.cfg
olimex-arm-usb-ocd.cfg
usb-jtag.cfg
flossjtag-noeeprom.cfg
olimex-arm-usb-ocd-h.cfg
usbprog.cfg
flyswatter2.cfg
olimex-arm-usb-tiny-h.cfg vpaclink.cfg
flyswatter.cfg
olimex-jtag-tiny.cfg
vsllink.cfg
hilscher_nxhx10_etm.cfg
oocdlink.cfg
xds100v2.cfg
hilscher_nxhx500_etm.cfg opendous.cfg
hilscher_nxhx500_re.cfg
openocd-usb.cfg
$
• ‘board’ ... think Circuit Board, PWA, PCB, they go by many names. Board files
contain initialization items that are specific to a board. They reuse target configuration
files, since the same microprocessor chips are used on many boards, but support for
external parts varies widely. For example, the SDRAM initialization sequence for the
board, or the type of external flash and what address it uses. Any initialization sequence
to enable that external flash or SDRAM should be found in the board file. Boards may
also contain multiple targets: two CPUs; or a CPU and an FPGA.
$ ls board
actux3.cfg
logicpd_imx27.cfg
am3517evm.cfg
lubbock.cfg
arm_evaluator7t.cfg
mcb1700.cfg
Chapter 6: Config File Guidelines
at91cap7a-stk-sdram.cfg
at91eb40a.cfg
at91rm9200-dk.cfg
at91rm9200-ek.cfg
at91sam9261-ek.cfg
at91sam9263-ek.cfg
at91sam9g20-ek.cfg
atmel_at91sam7s-ek.cfg
atmel_at91sam9260-ek.cfg
atmel_at91sam9rl-ek.cfg
atmel_sam3n_ek.cfg
atmel_sam3s_ek.cfg
atmel_sam3u_ek.cfg
atmel_sam3x_ek.cfg
atmel_sam4s_ek.cfg
balloon3-cpu.cfg
colibri.cfg
crossbow_tech_imote2.cfg
csb337.cfg
csb732.cfg
da850evm.cfg
digi_connectcore_wi-9c.cfg
diolan_lpc4350-db1.cfg
dm355evm.cfg
dm365evm.cfg
dm6446evm.cfg
efikamx.cfg
eir.cfg
ek-lm3s1968.cfg
ek-lm3s3748.cfg
ek-lm3s6965.cfg
ek-lm3s811.cfg
ek-lm3s811-revb.cfg
ek-lm3s9b9x.cfg
ek-lm4f232.cfg
embedded-artists_lpc2478-32.cfg
ethernut3.cfg
glyn_tonga2.cfg
hammer.cfg
hilscher_nxdb500sys.cfg
hilscher_nxeb500hmi.cfg
hilscher_nxhx10.cfg
hilscher_nxhx500.cfg
hilscher_nxhx50.cfg
hilscher_nxsb100.cfg
hitex_lpc2929.cfg
hitex_stm32-performancestick.cfg
21
microchip_explorer16.cfg
mini2440.cfg
mini6410.cfg
olimex_LPC2378STK.cfg
olimex_lpc_h2148.cfg
olimex_sam7_ex256.cfg
olimex_sam9_l9260.cfg
olimex_stm32_h103.cfg
olimex_stm32_h107.cfg
olimex_stm32_p107.cfg
omap2420_h4.cfg
open-bldc.cfg
openrd.cfg
osk5912.cfg
phytec_lpc3250.cfg
pic-p32mx.cfg
propox_mmnet1001.cfg
pxa255_sst.cfg
redbee.cfg
rsc-w910.cfg
sheevaplug.cfg
smdk6410.cfg
spear300evb.cfg
spear300evb_mod.cfg
spear310evb20.cfg
spear310evb20_mod.cfg
spear320cpu.cfg
spear320cpu_mod.cfg
steval_pcc010.cfg
stm320518_eval_stlink.cfg
stm32100b_eval.cfg
stm3210b_eval.cfg
stm3210c_eval.cfg
stm3210e_eval.cfg
stm3220g_eval.cfg
stm3220g_eval_stlink.cfg
stm3241g_eval.cfg
stm3241g_eval_stlink.cfg
stm32f0discovery.cfg
stm32f4discovery.cfg
stm32ldiscovery.cfg
stm32vldiscovery.cfg
str910-eval.cfg
telo.cfg
ti_beagleboard.cfg
ti_beagleboard_xm.cfg
ti_beaglebone.cfg
Chapter 6: Config File Guidelines
hitex_str9-comstick.cfg
iar_lpc1768.cfg
iar_str912_sk.cfg
icnova_imx53_sodimm.cfg
icnova_sam9g45_sodimm.cfg
imx27ads.cfg
imx27lnst.cfg
imx28evk.cfg
imx31pdk.cfg
imx35pdk.cfg
imx53loco.cfg
keil_mcb1700.cfg
keil_mcb2140.cfg
kwikstik.cfg
linksys_nslu2.cfg
lisa-l.cfg
$
22
ti_blaze.cfg
ti_pandaboard.cfg
ti_pandaboard_es.cfg
topas910.cfg
topasa900.cfg
twr-k60n512.cfg
tx25_stk5.cfg
tx27_stk5.cfg
unknown_at91sam9260.cfg
uptech_2410.cfg
verdex.cfg
voipac.cfg
voltcraft_dso-3062c.cfg
x300t.cfg
zy1000.cfg
• ‘target’ ... think chip. The “target” directory represents the JTAG TAPs on a chip
which OpenOCD should control, not a board. Two common types of targets are ARM
chips and FPGA or CPLD chips. When a chip has multiple TAPs (maybe it has both
ARM and DSP cores), the target config file defines all of them.
$ ls target
$duc702x.cfg
am335x.cfg
amdm37x.cfg
ar71xx.cfg
at32ap7000.cfg
at91r40008.cfg
at91rm9200.cfg
at91sam3ax_4x.cfg
at91sam3ax_8x.cfg
at91sam3ax_xx.cfg
at91sam3nXX.cfg
at91sam3sXX.cfg
at91sam3u1c.cfg
at91sam3u1e.cfg
at91sam3u2c.cfg
at91sam3u2e.cfg
at91sam3u4c.cfg
at91sam3u4e.cfg
at91sam3uxx.cfg
at91sam3XXX.cfg
at91sam4sXX.cfg
at91sam4XXX.cfg
at91sam7se512.cfg
at91sam7sx.cfg
ixp42x.cfg
k40.cfg
k60.cfg
lpc1768.cfg
lpc2103.cfg
lpc2124.cfg
lpc2129.cfg
lpc2148.cfg
lpc2294.cfg
lpc2378.cfg
lpc2460.cfg
lpc2478.cfg
lpc2900.cfg
lpc2xxx.cfg
lpc3131.cfg
lpc3250.cfg
lpc4350.cfg
mc13224v.cfg
nuc910.cfg
omap2420.cfg
omap3530.cfg
omap4430.cfg
omap4460.cfg
omap5912.cfg
Chapter 6: Config File Guidelines
at91sam7x256.cfg
at91sam7x512.cfg
at91sam9260.cfg
at91sam9260_ext_RAM_ext_flash.cfg
at91sam9261.cfg
at91sam9263.cfg
at91sam9.cfg
at91sam9g10.cfg
at91sam9g20.cfg
at91sam9g45.cfg
at91sam9rl.cfg
atmega128.cfg
avr32.cfg
c100.cfg
c100config.tcl
c100helper.tcl
c100regs.tcl
cs351x.cfg
davinci.cfg
dragonite.cfg
dsp56321.cfg
dsp568013.cfg
dsp568037.cfg
epc9301.cfg
faux.cfg
feroceon.cfg
fm3.cfg
hilscher_netx10.cfg
hilscher_netx500.cfg
hilscher_netx50.cfg
icepick.cfg
imx21.cfg
imx25.cfg
imx27.cfg
imx28.cfg
imx31.cfg
imx35.cfg
imx51.cfg
imx53.cfg
imx.cfg
is5114.cfg
23
omapl138.cfg
pic32mx.cfg
pxa255.cfg
pxa270.cfg
pxa3xx.cfg
readme.txt
samsung_s3c2410.cfg
samsung_s3c2440.cfg
samsung_s3c2450.cfg
samsung_s3c4510.cfg
samsung_s3c6410.cfg
sharp_lh79532.cfg
smp8634.cfg
spear3xx.cfg
stellaris.cfg
stm32.cfg
stm32f0x_stlink.cfg
stm32f1x.cfg
stm32f1x_stlink.cfg
stm32f2x.cfg
stm32f2x_stlink.cfg
stm32f2xxx.cfg
stm32f4x.cfg
stm32f4x_stlink.cfg
stm32l.cfg
stm32lx_stlink.cfg
stm32_stlink.cfg
stm32xl.cfg
str710.cfg
str730.cfg
str750.cfg
str912.cfg
swj-dp.tcl
test_reset_syntax_error.cfg
test_syntax_error.cfg
ti_dm355.cfg
ti_dm365.cfg
ti_dm6446.cfg
tmpa900.cfg
tmpa910.cfg
u8500.cfg
• more ... browse for other library files which may be useful. For example, there are
various generic and CPU-specific utilities.
The ‘openocd.cfg’ user config file may override features in any of the above files by setting
variables before sourcing the target file, or by adding commands specific to their situation.
Chapter 6: Config File Guidelines
24
6.1 Interface Config Files
The user config file should be able to source one of these files with a command like this:
source [find interface/FOOBAR.cfg]
A preconfigured interface file should exist for every debug adapter in use today with
OpenOCD. That said, perhaps some of these config files have only been used by the developer who created it.
A separate chapter gives information about how to set these up. See Chapter 8 [Debug
Adapter Configuration], page 38. Read the OpenOCD source code (and Developer’s Guide)
if you have a new kind of hardware interface and need to provide a driver for it.
6.2 Board Config Files
The user config file should be able to source one of these files with a command like this:
source [find board/FOOBAR.cfg]
The point of a board config file is to package everything about a given board that user
config files need to know. In summary the board files should contain (if present)
1. One or more source [target/...cfg] statements
2. NOR flash configuration (see [NOR Configuration], page 68)
3. NAND flash configuration (see [NAND Configuration], page 82)
4. Target reset handlers for SDRAM and I/O configuration
5. JTAG adapter reset configuration (see Chapter 9 [Reset Configuration], page 48)
6. All things that are not “inside a chip”
Generic things inside target chips belong in target config files, not board config files. So
for example a reset-init event handler should know board-specific oscillator and PLL
parameters, which it passes to target-specific utility code.
The most complex task of a board config file is creating such a reset-init event handler.
Define those handlers last, after you verify the rest of the board configuration works.
6.2.1 Communication Between Config files
In addition to target-specific utility code, another way that board and target config files
communicate is by following a convention on how to use certain variables.
The full Tcl/Tk language supports “namespaces”, but Jim-Tcl does not. Thus the rule we
follow in OpenOCD is this: Variables that begin with a leading underscore are temporary
in nature, and can be modified and used at will within a target configuration file.
Complex board config files can do the things like this, for a board with three chips:
# Chip #1: PXA270 for network side, big endian
set CHIPNAME network
set ENDIAN big
source [find target/pxa270.cfg]
# on return: _TARGETNAME = network.cpu
# other commands can refer to the "network.cpu" target.
$_TARGETNAME configure .... events for this CPU..
Chapter 6: Config File Guidelines
25
# Chip #2: PXA270 for video side, little endian
set CHIPNAME video
set ENDIAN little
source [find target/pxa270.cfg]
# on return: _TARGETNAME = video.cpu
# other commands can refer to the "video.cpu" target.
$_TARGETNAME configure .... events for this CPU..
# Chip #3: Xilinx FPGA for glue logic
set CHIPNAME xilinx
unset ENDIAN
source [find target/spartan3.cfg]
That example is oversimplified because it doesn’t show any flash memory, or the reset-init
event handlers to initialize external DRAM or (assuming it needs it) load a configuration
into the FPGA. Such features are usually needed for low-level work with many boards, where
“low level” implies that the board initialization software may not be working. (That’s a
common reason to need JTAG tools. Another is to enable working with microcontrollerbased systems, which often have no debugging support except a JTAG connector.)
Target config files may also export utility functions to board and user config files. Such
functions should use name prefixes, to help avoid naming collisions.
Board files could also accept input variables from user config files. For example, there might
be a J4_JUMPER setting used to identify what kind of flash memory a development board is
using, or how to set up other clocks and peripherals.
6.2.2 Variable Naming Convention
Most boards have only one instance of a chip. However, it should be easy to create a
board with more than one such chip (as shown above). Accordingly, we encourage these
conventions for naming variables associated with different ‘target.cfg’ files, to promote
consistency and so that board files can override target defaults.
Inputs to target config files include:
• CHIPNAME ... This gives a name to the overall chip, and is used as part of tap identifier
dotted names. While the default is normally provided by the chip manufacturer, board
files may need to distinguish between instances of a chip.
• ENDIAN ... By default ‘little’ - although chips may hard-wire ‘big’. Chips that can’t
change endianness don’t need to use this variable.
• CPUTAPID ... When OpenOCD examines the JTAG chain, it can be told verify the chips
against the JTAG IDCODE register. The target file will hold one or more defaults,
but sometimes the chip in a board will use a different ID (perhaps a newer revision).
Outputs from target config files include:
• _TARGETNAME ... By convention, this variable is created by the target configuration
script. The board configuration file may make use of this variable to configure things
like a “reset init” script, or other things specific to that board and that target. If the
chip has 2 targets, the names are _TARGETNAME0, _TARGETNAME1, ... etc.
Chapter 6: Config File Guidelines
26
6.2.3 The reset-init Event Handler
Board config files run in the OpenOCD configuration stage; they can’t use TAPs or targets,
since they haven’t been fully set up yet. This means you can’t write memory or access
chip registers; you can’t even verify that a flash chip is present. That’s done later in event
handlers, of which the target reset-init handler is one of the most important.
Except on microcontrollers, the basic job of reset-init event handlers is setting up flash
and DRAM, as normally handled by boot loaders. Microcontrollers rarely use boot loaders;
they run right out of their on-chip flash and SRAM memory. But they may want to use
one of these handlers too, if just for developer convenience.
Note: Because this is so very board-specific, and chip-specific, no examples
are included here. Instead, look at the board config files distributed with
OpenOCD. If you have a boot loader, its source code will help; so will configuration files for other JTAG tools (see [Translating Configuration Files], page 32).
Some of this code could probably be shared between different boards. For example, setting
up a DRAM controller often doesn’t differ by much except the bus width (16 bits or 32?)
and memory timings, so a reusable TCL procedure loaded by the ‘target.cfg’ file might
take those as parameters. Similarly with oscillator, PLL, and clock setup; and disabling the
watchdog. Structure the code cleanly, and provide comments to help the next developer
doing such work. (You might be that next person trying to reuse init code!)
The last thing normally done in a reset-init handler is probing whatever flash memory
was configured. For most chips that needs to be done while the associated target is halted,
either because JTAG memory access uses the CPU or to prevent conflicting CPU access.
6.2.4 JTAG Clock Rate
Before your reset-init handler has set up the PLLs and clocking, you may need to run
with a low JTAG clock rate. See [JTAG Speed], page 46. Then you’d increase that rate
after your handler has made it possible to use the faster JTAG clock. When the initial low
speed is board-specific, for example because it depends on a board-specific oscillator speed,
then you should probably set it up in the board config file; if it’s target-specific, it belongs
in the target config file.
For most ARM-based processors the fastest JTAG clock1 is one sixth of the CPU clock;
or one eighth for ARM11 cores. Consult chip documentation to determine the peak JTAG
clock rate, which might be less than that.
Warning: On most ARMs, JTAG clock detection is coupled to the core clock, so
software using a ‘wait for interrupt’ operation blocks JTAG access. Adaptive clocking provides a partial workaround, but a more complete solution just
avoids using that instruction with JTAG debuggers.
If both the chip and the board support adaptive clocking, use the jtag_rclk command, in
case your board is used with JTAG adapter which also supports it. Otherwise use adapter_
khz. Set the slow rate at the beginning of the reset sequence, and the faster rate as soon
as the clocks are at full speed.
1
A FAQ http://www.arm.com/support/faqdev/4170.html gives details.
Chapter 6: Config File Guidelines
27
6.2.5 The init board procedure
The concept of init_board procedure is very similar to init_targets (See [The init targets
procedure], page 31.) - it’s a replacement of “linear” configuration scripts. This procedure
is meant to be executed when OpenOCD enters run stage (See [Entering the Run Stage],
page 34,) after init_targets. The idea to have spearate init_targets and init_board
procedures is to allow the first one to configure everything target specific (internal flash,
internal RAM, etc.) and the second one to configure everything board specific (reset signals, chip frequency, reset-init event handler, external memory, etc.). Additionally “linear”
board config file will most likely fail when target config file uses init_targets scheme
(“linear” script is executed before init and init_targets - after), so separating these two
configuration stages is very convenient, as the easiest way to overcome this problem is to
convert board config file to use init_board procedure. Board config scripts don’t need to
override init_targets defined in target config files when they only need to to add some
specifics.
Just as init_targets, the init_board procedure can be overriden by “next level” script
(which sources the original), allowing greater code reuse.
### board_file.cfg ###
# source target file that does most of the config in init_targets
source [find target/target.cfg]
proc enable_fast_clock {} {
# enables fast on-board clock source
# configures the chip to use it
}
# initialize only board specifics - reset, clock, adapter frequency
proc init_board {} {
reset_config trst_and_srst trst_pulls_srst
$_TARGETNAME configure -event reset-init {
adapter_khz 1
enable_fast_clock
adapter_khz 10000
}
}
6.3 Target Config Files
Board config files communicate with target config files using naming conventions as described above, and may source one or more target config files like this:
source [find target/FOOBAR.cfg]
The point of a target config file is to package everything about a given chip that board
config files need to know. In summary the target files should contain
1. Set defaults
2. Add TAPs to the scan chain
Chapter 6: Config File Guidelines
28
3. Add CPU targets (includes GDB support)
4. CPU/Chip/CPU-Core specific features
5. On-Chip flash
As a rule of thumb, a target file sets up only one chip. For a microcontroller, that will often
include a single TAP, which is a CPU needing a GDB target, and its on-chip flash.
More complex chips may include multiple TAPs, and the target config file may need to
define them all before OpenOCD can talk to the chip. For example, some phone chips have
JTAG scan chains that include an ARM core for operating system use, a DSP, another
ARM core embedded in an image processing engine, and other processing engines.
6.3.1 Default Value Boiler Plate Code
All target configuration files should start with code like this, letting board config files express
environment-specific differences in how things should be set up.
# Boards may override chip names, perhaps based on role,
# but the default should match what the vendor uses
if { [info exists CHIPNAME] } {
set _CHIPNAME $CHIPNAME
} else {
set _CHIPNAME sam7x256
}
# ONLY use ENDIAN with targets that can change it.
if { [info exists ENDIAN] } {
set _ENDIAN $ENDIAN
} else {
set _ENDIAN little
}
# TAP identifiers may change as chips mature, for example with
# new revision fields (the "3" here). Pick a good default; you
# can pass several such identifiers to the "jtag newtap" command.
if { [info exists CPUTAPID ] } {
set _CPUTAPID $CPUTAPID
} else {
set _CPUTAPID 0x3f0f0f0f
}
Remember: Board config files may include multiple target config files, or the same target
file multiple times (changing at least CHIPNAME).
Likewise, the target configuration file should define _TARGETNAME (or _TARGETNAME0 etc)
and use it later on when defining debug targets:
set _TARGETNAME $_CHIPNAME.cpu
target create $_TARGETNAME arm7tdmi -chain-position $_TARGETNAME
Chapter 6: Config File Guidelines
29
6.3.2 Adding TAPs to the Scan Chain
After the “defaults” are set up, add the TAPs on each chip to the JTAG scan chain. See
Chapter 10 [TAP Declaration], page 53, and the naming convention for taps.
In the simplest case the chip has only one TAP, probably for a CPU or FPGA. The config
file for the Atmel AT91SAM7X256 looks (in part) like this:
jtag newtap $_CHIPNAME cpu -irlen 4 -expected-id $_CPUTAPID
A board with two such at91sam7 chips would be able to source such a config file twice, with
different values for CHIPNAME, so it adds a different TAP each time.
If there are nonzero ‘-expected-id’ values, OpenOCD attempts to verify the actual tap id
against those values. It will issue error messages if there is mismatch, which can help to
pinpoint problems in OpenOCD configurations.
JTAG tap: sam7x256.cpu tap/device found: 0x3f0f0f0f
(Manufacturer: 0x787, Part: 0xf0f0, Version: 0x3)
ERROR: Tap: sam7x256.cpu - Expected id: 0x12345678, Got: 0x3f0f0f0f
ERROR: expected: mfg: 0x33c, part: 0x2345, ver: 0x1
ERROR:
got: mfg: 0x787, part: 0xf0f0, ver: 0x3
There are more complex examples too, with chips that have multiple TAPs. Ones worth
looking at include:
• ‘target/omap3530.cfg’ – with disabled ARM and DSP, plus a JRC to enable them
• ‘target/str912.cfg’ – with flash, CPU, and boundary scan
• ‘target/ti_dm355.cfg’ – with ETM, ARM, and JRC (this JRC is not currently used)
6.3.3 Add CPU targets
After adding a TAP for a CPU, you should set it up so that GDB and other commands can
use it. See Chapter 11 [CPU Configuration], page 59. For the at91sam7 example above, the
command can look like this; note that $_ENDIAN is not needed, since OpenOCD defaults to
little endian, and this chip doesn’t support changing that.
set _TARGETNAME $_CHIPNAME.cpu
target create $_TARGETNAME arm7tdmi -chain-position $_TARGETNAME
Work areas are small RAM areas associated with CPU targets. They are used by OpenOCD
to speed up downloads, and to download small snippets of code to program flash chips. If
the chip includes a form of “on-chip-ram” - and many do - define a work area if you can.
Again using the at91sam7 as an example, this can look like:
$_TARGETNAME configure -work-area-phys 0x00200000 \
-work-area-size 0x4000 -work-area-backup 0
6.3.4 Define CPU targets working in SMP
After setting targets, you can define a list of targets working in SMP.
set _TARGETNAME_1 $_CHIPNAME.cpu1
set _TARGETNAME_2 $_CHIPNAME.cpu2
target create $_TARGETNAME_1 cortex_a8 -chain-position $_CHIPNAME.dap \
-coreid 0 -dbgbase $_DAP_DBG1
target create $_TARGETNAME_2 cortex_a8 -chain-position $_CHIPNAME.dap \
Chapter 6: Config File Guidelines
30
-coreid 1 -dbgbase $_DAP_DBG2
#define 2 targets working in smp.
target smp $_CHIPNAME.cpu2 $_CHIPNAME.cpu1
In the above example on cortex a8, 2 cpus are working in SMP. In SMP only one GDB
instance is created and :
• a set of hardware breakpoint sets the same breakpoint on all targets in the list.
• halt command triggers the halt of all targets in the list.
• resume command triggers the write context and the restart of all targets in the list.
• following a breakpoint: the target stopped by the breakpoint is displayed to the GDB
session.
• dedicated GDB serial protocol packets are implemented for switching/retrieving the
target displayed by the GDB session see [Using openocd SMP with GDB], page 116.
The SMP behaviour can be disabled/enabled dynamically. On cortex a8 following command
have been implemented.
• cortex a8 smp on : enable SMP mode, behaviour is as described above.
• cortex a8 smp off : disable SMP mode, the current target is the one displayed in the
GDB session, only this target is now controlled by GDB session. This behaviour is
useful during system boot up.
• cortex a8 smp gdb : display/fix the core id displayed in GDB session see following
example.
>cortex_a8 smp_gdb
gdb coreid 0 -> -1
#0 : coreid 0 is displayed to GDB ,
#-> -1 : next resume triggers a real resume
> cortex_a8 smp_gdb 1
gdb coreid 0 -> 1
#0 :coreid 0 is displayed to GDB ,
#->1 : next resume displays coreid 1 to GDB
> resume
> cortex_a8 smp_gdb
gdb coreid 1 -> 1
#1 :coreid 1 is displayed to GDB ,
#->1 : next resume displays coreid 1 to GDB
> cortex_a8 smp_gdb -1
gdb coreid 1 -> -1
#1 :coreid 1 is displayed to GDB,
#->-1 : next resume triggers a real resume
6.3.5 Chip Reset Setup
As a rule, you should put the reset_config command into the board file. Most things you
think you know about a chip can be tweaked by the board.
Some chips have specific ways the TRST and SRST signals are managed. In the unusual
case that these are chip specific and can never be changed by board wiring, they could go
here. For example, some chips can’t support JTAG debugging without both signals.
Chapter 6: Config File Guidelines
31
Provide a reset-assert event handler if you can. Such a handler uses JTAG operations
to reset the target, letting this target config be used in systems which don’t provide the
optional SRST signal, or on systems where you don’t want to reset all targets at once. Such
a handler might write to chip registers to force a reset, use a JRC to do that (preferable –
the target may be wedged!), or force a watchdog timer to trigger. (For Cortex-M3 targets,
this is not necessary. The target driver knows how to use trigger an NVIC reset when SRST
is not available.)
Some chips need special attention during reset handling if they’re going to be used with
JTAG. An example might be needing to send some commands right after the target’s TAP
has been reset, providing a reset-deassert-post event handler that writes a chip register
to report that JTAG debugging is being done. Another would be reconfiguring the watchdog
so that it stops counting while the core is halted in the debugger.
JTAG clocking constraints often change during reset, and in some cases target config files
(rather than board config files) are the right places to handle some of those issues. For
example, immediately after reset most chips run using a slower clock than they will use
later. That means that after reset (and potentially, as OpenOCD first starts up) they must
use a slower JTAG clock rate than they will use later. See [JTAG Speed], page 46.
Important: When you are debugging code that runs right after chip reset,
getting these issues right is critical. In particular, if you see intermittent failures
when OpenOCD verifies the scan chain after reset, look at how you are setting
up JTAG clocking.
6.3.6 The init targets procedure
Target config files can either be “linear” (script executed line-by-line when parsed in configuration stage, See [Configuration Stage], page 34,) or they can contain a special procedure
called init_targets, which will be executed when entering run stage (after parsing all
config files or after init command, See [Entering the Run Stage], page 34.) Such procedure
can be overriden by “next level” script (which sources the original). This concept faciliates code reuse when basic target config files provide generic configuration procedures and
init_targets procedure, which can then be sourced and enchanced or changed in a “more
specific” target config file. This is not possible with “linear” config scripts, because sourcing
them executes every initialization commands they provide.
### generic_file.cfg ###
proc setup_my_chip {chip_name flash_size ram_size} {
# basic initialization procedure ...
}
proc init_targets {} {
# initializes generic chip with 4kB of flash and 1kB of RAM
setup_my_chip MY_GENERIC_CHIP 4096 1024
}
### specific_file.cfg ###
source [find target/generic_file.cfg]
Chapter 6: Config File Guidelines
32
proc init_targets {} {
# initializes specific chip with 128kB of flash and 64kB of RAM
setup_my_chip MY_CHIP_WITH_128K_FLASH_64KB_RAM 131072 65536
}
The easiest way to convert “linear” config files to init_targets version is to enclose every
line of “code” (i.e. not source commands, procedures, etc.) in this procedure.
For an example of this scheme see LPC2000 target config files.
The init_boards procedure is a similar concept concerning board config files (See [The
init board procedure], page 26.)
6.3.7 ARM Core Specific Hacks
If the chip has a DCC, enable it. If the chip is an ARM9 with some special high speed
download features - enable it.
If present, the MMU, the MPU and the CACHE should be disabled.
Some ARM cores are equipped with trace support, which permits examination of the instruction and data bus activity. Trace activity is controlled through an “Embedded Trace
Module” (ETM) on one of the core’s scan chains. The ETM emits voluminous data through
a “trace port”. (See [ARM Hardware Tracing], page 96.) If you are using an external trace
port, configure it in your board config file. If you are using an on-chip “Embedded Trace
Buffer” (ETB), configure it in your target config file.
etm config $_TARGETNAME 16 normal full etb
etb config $_TARGETNAME $_CHIPNAME.etb
6.3.8 Internal Flash Configuration
This applies ONLY TO MICROCONTROLLERS that have flash built in.
Never ever in the “target configuration file” define any type of flash that is external to the
chip. (For example a BOOT flash on Chip Select 0.) Such flash information goes in a board
file - not the TARGET (chip) file.
Examples:
• at91sam7x256 - has 256K flash YES enable it.
• str912 - has flash internal YES enable it.
• imx27 - uses boot flash on CS0 - it goes in the board file.
• pxa270 - again - CS0 flash - it goes in the board file.
6.4 Translating Configuration Files
If you have a configuration file for another hardware debugger or toolset (Abatron, BDI2000,
BDI3000, CCS, Lauterbach, Segger, Macraigor, etc.), translating it into OpenOCD syntax
is often quite straightforward. The most tricky part of creating a configuration script is
oftentimes the reset init sequence where e.g. PLLs, DRAM and the like is set up.
One trick that you can use when translating is to write small Tcl procedures to translate
the syntax into OpenOCD syntax. This can avoid manual translation errors and make it
easier to convert other scripts later on.
Example of transforming quirky arguments to a simple search and replace job:
Chapter 6: Config File Guidelines
#
#
#
#
#
#
#
Lauterbach syntax(?)
Data.Set c15:0x042f %long 0x40000015
OpenOCD syntax when using procedure below.
setc15 0x01 0x00050078
proc setc15 {regs value} {
global TARGETNAME
echo [format "set p15 0x%04x, 0x%08x" $regs $value]
arm mcr 15 [expr ($regs>>12)&0x7] \
[expr ($regs>>0)&0xf] [expr ($regs>>4)&0xf] \
[expr ($regs>>8)&0x7] $value
}
33
Chapter 7: Daemon Configuration
34
7 Daemon Configuration
The commands here are commonly found in the openocd.cfg file and are used to specify
what TCP/IP ports are used, and how GDB should be supported.
7.1 Configuration Stage
When the OpenOCD server process starts up, it enters a configuration stage which is the
only time that certain commands, configuration commands, may be issued. Normally, configuration commands are only available inside startup scripts.
In this manual, the definition of a configuration command is presented as a Config Command, not as a Command which may be issued interactively. The runtime help command
also highlights configuration commands, and those which may be issued at any time.
Those configuration commands include declaration of TAPs, flash banks, the interface used
for JTAG communication, and other basic setup. The server must leave the configuration stage before it may access or activate TAPs. After it leaves this stage, configuration
commands may no longer be issued.
7.2 Entering the Run Stage
The first thing OpenOCD does after leaving the configuration stage is to verify that it can
talk to the scan chain (list of TAPs) which has been configured. It will warn if it doesn’t
find TAPs it expects to find, or finds TAPs that aren’t supposed to be there. You should
see no errors at this point. If you see errors, resolve them by correcting the commands you
used to configure the server. Common errors include using an initial JTAG speed that’s
too fast, and not providing the right IDCODE values for the TAPs on the scan chain.
Once OpenOCD has entered the run stage, a number of commands become available. A
number of these relate to the debug targets you may have declared. For example, the mww
command will not be available until a target has been successfuly instantiated. If you want
to use those commands, you may need to force entry to the run stage.
init
[Config Command]
This command terminates the configuration stage and enters the run stage. This helps
when you need to have the startup scripts manage tasks such as resetting the target,
programming flash, etc. To reset the CPU upon startup, add "init" and "reset" at
the end of the config script or at the end of the OpenOCD command line using the
‘-c’ command line switch.
If this command does not appear in any startup/configuration file OpenOCD executes
the command for you after processing all configuration files and/or command line
options.
NOTE: This command normally occurs at or near the end of your openocd.cfg file
to force OpenOCD to “initialize” and make the targets ready. For example: If your
openocd.cfg file needs to read/write memory on your target, init must occur before
the memory read/write commands. This includes nand probe.
[Overridable Procedure]
This is invoked at server startup to verify that it can talk to the scan chain (list of
TAPs) which has been configured.
jtag_init
Chapter 7: Daemon Configuration
35
The default implementation first tries jtag arp_init, which uses only a lightweight
JTAG reset before examining the scan chain. If that fails, it tries again, using a
harder reset from the overridable procedure init_reset.
Implementations must have verified the JTAG scan chain before they return. This is
done by calling jtag arp_init (or jtag arp_init-reset).
7.3 TCP/IP Ports
The OpenOCD server accepts remote commands in several syntaxes. Each syntax uses a
different TCP/IP port, which you may specify only during configuration (before those ports
are opened).
For reasons including security, you may wish to prevent remote access using one or more of
these ports. In such cases, just specify the relevant port number as zero. If you disable all
access through TCP/IP, you will need to use the command line ‘-pipe’ option.
gdb_port [number]
[Command]
Normally gdb listens to a TCP/IP port, but GDB can also communicate via
pipes(stdin/out or named pipes). The name "gdb port" stuck because it covers
probably more than 90% of the normal use cases.
No arguments reports GDB port. "pipe" means listen to stdin output to stdout, an
integer is base port number, "disable" disables the gdb server.
When using "pipe", also use log output to redirect the log output to a file so as not
to flood the stdin/out pipes.
The -p/–pipe option is deprecated and a warning is printed as it is equivalent to
passing in -c "gdb port pipe; log output openocd.log".
Any other string is interpreted as named pipe to listen to. Output pipe is the same
name as input pipe, but with ’o’ appended, e.g. /var/gdb, /var/gdbo.
The GDB port for the first target will be the base port, the second target will listen
on gdb port + 1, and so on. When not specified during the configuration stage, the
port number defaults to 3333.
tcl_port [number]
[Command]
Specify or query the port used for a simplified RPC connection that can be used by
clients to issue TCL commands and get the output from the Tcl engine. Intended
as a machine interface. When not specified during the configuration stage, the port
number defaults to 6666.
telnet_port [number]
[Command]
Specify or query the port on which to listen for incoming telnet connections. This
port is intended for interaction with one human through TCL commands. When not
specified during the configuration stage, the port number defaults to 4444. When
specified as zero, this port is not activated.
7.4 GDB Configuration
You can reconfigure some GDB behaviors if needed. The ones listed here are static and
global. See [Target Configuration], page 61, about configuring individual targets. See
[Target Events], page 64, about configuring target-specific event handling.
Chapter 7: Daemon Configuration
36
gdb_breakpoint_override [‘hard’|‘soft’|‘disable’]
[Command]
Force breakpoint type for gdb break commands. This option supports GDB GUIs
which don’t distinguish hard versus soft breakpoints, if the default OpenOCD and
GDB behaviour is not sufficient. GDB normally uses hardware breakpoints if the
memory map has been set up for flash regions.
gdb_flash_program (‘enable’|‘disable’)
[Config Command]
Set to ‘enable’ to cause OpenOCD to program the flash memory when a vFlash
packet is received. The default behaviour is ‘enable’.
gdb_memory_map (‘enable’|‘disable’)
[Config Command]
Set to ‘enable’ to cause OpenOCD to send the memory configuration to GDB when
requested. GDB will then know when to set hardware breakpoints, and program flash
using the GDB load command. gdb_flash_program enable must also be enabled for
flash programming to work. Default behaviour is ‘enable’. See [gdb flash program],
page 36.
gdb_report_data_abort (‘enable’|‘disable’)
[Config Command]
Specifies whether data aborts cause an error to be reported by GDB memory read
packets. The default behaviour is ‘disable’; use ‘enable’ see these errors reported.
7.5 Event Polling
Hardware debuggers are parts of asynchronous systems, where significant events can happen
at any time. The OpenOCD server needs to detect some of these events, so it can report
them to through TCL command line or to GDB.
Examples of such events include:
• One of the targets can stop running ... maybe it triggers a code breakpoint or data
watchpoint, or halts itself.
• Messages may be sent over “debug message” channels ... many targets support such
messages sent over JTAG, for receipt by the person debugging or tools.
• Loss of power ... some adapters can detect these events.
• Resets not issued through JTAG ... such reset sources can include button presses
or other system hardware, sometimes including the target itself (perhaps through a
watchdog).
• Debug instrumentation sometimes supports event triggering such as “trace buffer full”
(so it can quickly be emptied) or other signals (to correlate with code behavior).
None of those events are signaled through standard JTAG signals. However, most conventions for JTAG connectors include voltage level and system reset (SRST) signal detection.
Some connectors also include instrumentation signals, which can imply events when those
signals are inputs.
In general, OpenOCD needs to periodically check for those events, either by looking at the
status of signals on the JTAG connector or by sending synchronous “tell me your status”
JTAG requests to the various active targets. There is a command to manage and monitor
that polling, which is normally done in the background.
Chapter 7: Daemon Configuration
poll [‘on’|‘off’]
37
[Command]
Poll the current target for its current state. (Also, see [target curstate], page 64.)
If that target is in debug mode, architecture specific information about the current
state is printed. An optional parameter allows background polling to be enabled and
disabled.
You could use this from the TCL command shell, or from GDB using monitor poll
command. Leave background polling enabled while you’re using GDB.
> poll
background polling: on
target state: halted
target halted in ARM state due to debug-request, \
current mode: Supervisor
cpsr: 0x800000d3 pc: 0x11081bfc
MMU: disabled, D-Cache: disabled, I-Cache: enabled
>
Chapter 8: Debug Adapter Configuration
38
8 Debug Adapter Configuration
Correctly installing OpenOCD includes making your operating system give OpenOCD access to debug adapters. Once that has been done, Tcl commands are used to select which
one is used, and to configure how it is used.
Note: Because OpenOCD started out with a focus purely on JTAG, you may
find places where it wrongly presumes JTAG is the only transport protocol in
use. Be aware that recent versions of OpenOCD are removing that limitation.
JTAG remains more functional than most other transports. Other transports
do not support boundary scan operations, or may be specific to a given chip
vendor. Some might be usable only for programming flash memory, instead of
also for debugging.
Debug Adapters/Interfaces/Dongles are normally configured through commands in an interface configuration file which is sourced by your ‘openocd.cfg’ file, or through a command
line ‘-f interface/....cfg’ option.
source [find interface/olimex-jtag-tiny.cfg]
These commands tell OpenOCD what type of JTAG adapter you have, and how to talk to
it. A few cases are so simple that you only need to say what driver to use:
# jlink interface
interface jlink
Most adapters need a bit more configuration than that.
8.1 Interface Configuration
The interface command tells OpenOCD what type of debug adapter you are using. Depending on the type of adapter, you may need to use one or more additional commands to
further identify or configure the adapter.
interface name
[Config Command]
Use the interface driver name to connect to the target.
[Command]
List the debug adapter drivers that have been built into the running copy of
OpenOCD.
interface_list
interface transports transport name+
[Command]
Specifies the transports supported by this debug adapter. The adapter driver buildsin similar knowledge; use this only when external configuration (such as jumpering)
changes what the hardware can support.
adapter_name
Returns the name of the debug adapter driver being used.
[Command]
Chapter 8: Debug Adapter Configuration
39
8.2 Interface Drivers
Each of the interface drivers listed here must be explicitly enabled when OpenOCD is
configured, in order to be made available at run time.
[Interface Driver]
Amontec Chameleon in its JTAG Accelerator configuration, connected to a PC’s EPP
mode parallel port. This defines some driver-specific commands:
amt_jtagaccel
parport_port number
[Config Command]
Specifies either the address of the I/O port (default: 0x378 for LPT1) or the
number of the ‘/dev/parport’ device.
rtck [‘enable’|‘disable’]
[Config Command]
Displays status of RTCK option. Optionally sets that option first.
[Interface Driver]
Olimex ARM-JTAG-EW USB adapter This has one driver-specific command:
arm-jtag-ew
armjtagew_info
[Command]
Logs some status
[Interface Driver]
Supports bitbanged JTAG from the local system, presuming that system is an Atmel
AT91rm9200 and a specific set of GPIOs is used.
at91rm9200
[Interface Driver]
dummy
A dummy software-only driver for debugging.
[Interface Driver]
Cirrus Logic EP93xx based single-board computer bit-banging (in development)
ep93xx
[Interface Driver]
FTDI FT2232 (USB) based devices over one of the userspace libraries. These interfaces have several commands, used to configure the driver before initializing the
JTAG scan chain:
ft2232
ft2232_device_desc description
[Config Command]
Provides the USB device description (the iProduct string) of the FTDI FT2232
device. If not specified, the FTDI default value is used. This setting is only
valid if compiled with FTD2XX support.
ft2232_serial serial-number
[Config Command]
Specifies the serial-number of the FTDI FT2232 device to use, in case the
vendor provides unique IDs and more than one FT2232 device is connected
to the host. If not specified, serial numbers are not considered. (Note that
USB serial numbers can be arbitrary Unicode strings, and are not restricted to
containing only decimal digits.)
ft2232_layout name
[Config Command]
Each vendor’s FT2232 device can use different GPIO signals to control outputenables, reset signals, and LEDs. Currently valid layout name values include:
Chapter 8: Debug Adapter Configuration
40
− axm0432 jtag Axiom AXM-0432
− comstick Hitex STR9 comstick
− cortino Hitex Cortino JTAG interface
− evb lm3s811 Luminary Micro EVB LM3S811 as a JTAG interface, either
for the local Cortex-M3 (SRST only) or in a passthrough mode (neither
SRST nor TRST) This layout can not support the SWO trace mechanism,
and should be used only for older boards (before rev C).
− luminary icdi This layout should be used with most Luminary eval boards,
including Rev C LM3S811 eval boards and the eponymous ICDI boards, to
debug either the local Cortex-M3 or in passthrough mode to debug some
other target. It can support the SWO trace mechanism.
− flyswatter Tin Can Tools Flyswatter
− icebear ICEbear JTAG adapter from Section 5
− jtagkey Amontec JTAGkey and JTAGkey-Tiny (and compatibles)
− jtagkey2 Amontec JTAGkey2 (and compatibles)
− m5960 American Microsystems M5960
− olimex-jtag Olimex ARM-USB-OCD and ARM-USB-Tiny
− oocdlink OOCDLink
− redbee-econotag Integrated with a Redbee development board.
− redbee-usb Integrated with a Redbee USB-stick development board.
− sheevaplug Marvell Sheevaplug development kit
− signalyzer Xverve Signalyzer
− stm32stick Hitex STM32 Performance Stick
− turtelizer2 egnite Software turtelizer2
− usbjtag "USBJTAG-1" layout described in the OpenOCD diploma thesis
ft2232_vid_pid [vid pid]+
[Config Command]
The vendor ID and product ID of the FTDI FT2232 device. If not specified,
the FTDI default values are used. Currently, up to eight [vid, pid] pairs may
be given, e.g.
ft2232_vid_pid 0x0403 0xcff8 0x15ba 0x0003
ft2232_latency ms
[Config Command]
On some systems using FT2232 based JTAG interfaces the FT Read function
call in ft2232 read() fails to return the expected number of bytes. This can
be caused by USB communication delays and has proved hard to reproduce
and debug. Setting the FT2232 latency timer to a larger value increases delays
for short USB packets but it also reduces the risk of timeouts before receiving
the expected number of bytes. The OpenOCD default value is 2 and for some
systems a value of 10 has proved useful.
For example, the interface config file for a Turtelizer JTAG Adapter looks something
like this:
Chapter 8: Debug Adapter Configuration
41
interface ft2232
ft2232_device_desc "Turtelizer JTAG/RS232 Adapter"
ft2232_layout turtelizer2
ft2232_vid_pid 0x0403 0xbdc8
[Interface Driver]
Drive JTAG from a remote process. This sets up a UNIX or TCP socket connection
with a remote process and sends ASCII encoded bitbang requests to that process
instead of directly driving JTAG.
The remote bitbang driver is useful for debugging software running on processors
which are being simulated.
remote_bitbang
remote_bitbang_port number
[Config Command]
Specifies the TCP port of the remote process to connect to or 0 to use UNIX
sockets instead of TCP.
remote_bitbang_host hostname
[Config Command]
Specifies the hostname of the remote process to connect to using TCP, or the
name of the UNIX socket to use if remote bitbang port is 0.
For example, to connect remotely via TCP to the host foobar you might have something like:
interface remote_bitbang
remote_bitbang_port 3335
remote_bitbang_host foobar
To connect to another process running locally via UNIX sockets with socket named
mysocket:
interface remote_bitbang
remote_bitbang_port 0
remote_bitbang_host mysocket
[Interface Driver]
USB JTAG/USB-Blaster compatibles over one of the userspace libraries for FTDI
chips. These interfaces have several commands, used to configure the driver before
initializing the JTAG scan chain:
usb_blaster
usb_blaster_device_desc description
[Config Command]
Provides the USB device description (the iProduct string) of the FTDI FT245
device. If not specified, the FTDI default value is used. This setting is only
valid if compiled with FTD2XX support.
usb_blaster_vid_pid vid pid
[Config Command]
The vendor ID and product ID of the FTDI FT245 device. If not specified,
default values are used. Currently, only one vid, pid pair may be given, e.g. for
Altera USB-Blaster (default):
usb_blaster_vid_pid 0x09FB 0x6001
The following VID/PID is for Kolja Waschk’s USB JTAG:
usb_blaster_vid_pid 0x16C0 0x06AD
Chapter 8: Debug Adapter Configuration
42
usb_blaster (‘pin6’|‘pin8’) (‘0’|‘1’)
[Command]
Sets the state of the unused GPIO pins on USB-Blasters (pins 6 and 8 on the
female JTAG header). These pins can be used as SRST and/or TRST provided
the appropriate connections are made on the target board.
For example, to use pin 6 as SRST (as with an AVR board):
$_TARGETNAME configure -event reset-assert \
"usb_blaster pin6 1; wait 1; usb_blaster pin6 0"
[Interface Driver]
Gateworks GW16012 JTAG programmer. This has one driver-specific command:
gw16012
parport_port [port number]
[Config Command]
Display either the address of the I/O port (default: 0x378 for LPT1) or the
number of the ‘/dev/parport’ device. If a parameter is provided, first switch
to use that port. This is a write-once setting.
[Interface Driver]
Segger J-Link family of USB adapters. It currently supports only the JTAG transport.
Compatibility Note: Segger released many firmware versions for the many
harware versions they produced. OpenOCD was extensively tested and
intended to run on all of them, but some combinations were reported as
incompatible. As a general recommendation, it is advisable to use the
latest firmware version available for each hardware version. However the
current V8 is a moving target, and Segger firmware versions released after
the OpenOCD was released may not be compatible. In such cases it is
recommended to revert to the last known functional version. For 0.5.0,
this is from "Feb 8 2012 14:30:39", packed with 4.42c. For 0.6.0, the last
known version is from "May 3 2012 18:36:22", packed with 4.46f.
jlink
jlink caps
[Command]
Display the device firmware capabilities.
[Command]
Display various device information, like hardware version, firmware version,
current bus status.
jlink info
jlink hw_jtag [‘2’|‘3’]
[Command]
Set the JTAG protocol version to be used. Without argument, show the actual
JTAG protocol version.
jlink config
[Command]
Display the J-Link configuration.
jlink config kickstart [val]
[Command]
Set the Kickstart power on JTAG-pin 19. Without argument, show the Kickstart configuration.
jlink config mac_address [‘ff:ff:ff:ff:ff:ff’]
[Command]
Set the MAC address of the J-Link Pro. Without argument, show the MAC
address.
Chapter 8: Debug Adapter Configuration
43
jlink config ip [‘A.B.C.D’(‘/E’|‘F.G.H.I’)]
[Command]
Set the IP configuration of the J-Link Pro, where A.B.C.D is the IP address, E
the bit of the subnet mask and F.G.H.I the subnet mask. Without arguments,
show the IP configuration.
jlink config usb_address [‘0x00’ to ‘0x03’ or ‘0xff’]
[Command]
Set the USB address; this will also change the product id. Without argument,
show the USB address.
jlink config reset
[Command]
Reset the current configuration.
jlink config save
[Command]
Save the current configuration to the internal persistent storage.
jlink pid val
[Config]
Set the USB PID of the interface. As a configuration command, it can be used
only before ’init’.
[Interface Driver]
Supports PC parallel port bit-banging cables: Wigglers, PLD download cable, and
more. These interfaces have several commands, used to configure the driver before
initializing the JTAG scan chain:
parport
parport_cable name
[Config Command]
Set the layout of the parallel port cable used to connect to the target. This is
a write-once setting. Currently valid cable name values include:
− altium Altium Universal JTAG cable.
− arm-jtag Same as original wiggler except SRST and TRST connections
reversed and TRST is also inverted.
− chameleon The Amontec Chameleon’s CPLD when operated in configuration mode. This is only used to program the Chameleon itself, not a
connected target.
− dlc5 The Xilinx Parallel cable III.
− flashlink The ST Parallel cable.
− lattice Lattice ispDOWNLOAD Cable
− old amt wiggler The Wiggler configuration that comes with some versions
of Amontec’s Chameleon Programmer. The new version available from the
website uses the original Wiggler layout (’wiggler’)
− triton The parallel port adapter found on the “Karo Triton 1 Development
Board”. This is also the layout used by the HollyGates design (see http://
www.lartmaker.nl/projects/jtag/).
− wiggler The original Wiggler layout, also supported by several clones, such
as the Olimex ARM-JTAG
− wiggler2 Same as original wiggler except an led is fitted on D5.
− wiggler ntrst inverted Same as original wiggler except TRST is inverted.
Chapter 8: Debug Adapter Configuration
44
parport_port [port number]
[Config Command]
Display either the address of the I/O port (default: 0x378 for LPT1) or the
number of the ‘/dev/parport’ device. If a parameter is provided, first switch
to use that port. This is a write-once setting.
When using PPDEV to access the parallel port, use the number of the parallel
port: ‘parport_port 0’ (the default). If ‘parport_port 0x378’ is specified you
may encounter a problem.
parport_toggling_time [nanoseconds]
[Command]
Displays how many nanoseconds the hardware needs to toggle TCK; the parport
driver uses this value to obey the adapter_khz configuration. When the optional nanoseconds parameter is given, that setting is changed before displaying
the current value.
The default setting should work reasonably well on commodity PC hardware.
However, you may want to calibrate for your specific hardware.
Tip: To measure the toggling time with a logic analyzer or a digital
storage oscilloscope, follow the procedure below:
> parport_toggling_time 1000
> adapter_khz 500
This sets the maximum JTAG clock speed of the hardware, but the
actual speed probably deviates from the requested 500 kHz. Now,
measure the time between the two closest spaced TCK transitions.
You can use runtest 1000 or something similar to generate a large
set of samples. Update the setting to match your measurement:
> parport_toggling_time <measured nanoseconds>
Now the clock speed will be a better match for adapter_khz rate
commands given in OpenOCD scripts and event handlers.
You can do something similar with many digital multimeters, but
note that you’ll probably need to run the clock continuously for
several seconds before it decides what clock rate to show. Adjust
the toggling time up or down until the measured clock rate is a good
match for the adapter khz rate you specified; be conservative.
parport_write_on_exit (‘on’|‘off’)
[Config Command]
This will configure the parallel driver to write a known cable-specific value to
the parallel interface on exiting OpenOCD.
For example, the interface configuration file for a classic “Wiggler” cable on LPT2
might look something like this:
interface parport
parport_port 0x278
parport_cable wiggler
presto
ASIX PRESTO USB JTAG programmer.
[Interface Driver]
Chapter 8: Debug Adapter Configuration
45
presto_serial serial string
[Config Command]
Configures the USB serial number of the Presto device to use.
[Interface Driver]
rlink
Raisonance RLink USB adapter
[Interface Driver]
usbprog
usbprog is a freely programmable USB adapter.
[Interface Driver]
vsllink
vsllink is part of Versaloon which is a versatile USB programmer.
Note: This defines quite a few driver-specific commands, which are not
currently documented here.
[Interface Driver]
stlink
ST Micro ST-LINK adapter.
stlink_device_desc description
[Config Command]
Currently Not Supported.
stlink_serial serial
[Config Command]
Currently Not Supported.
stlink_layout (‘sg’|‘usb’)
[Config Command]
Specifies the stlink layout to use.
stlink_vid_pid vid pid
[Config Command]
The vendor ID and product ID of the STLINK device.
stlink_api api level
[Config Command]
Manually sets the stlink api used, valid options are 1 or 2.
opendous
[Interface Driver]
opendous-jtag is a freely programmable USB adapter.
ulink
[Interface Driver]
This is the Keil ULINK v1 JTAG debugger.
ZY1000
[Interface Driver]
This is the Zylin ZY1000 JTAG debugger.
Note: This defines some driver-specific commands, which are not currently
documented here.
power [‘on’|‘off’]
Turn power switch to target on/off. No arguments: print status.
[Command]
Chapter 8: Debug Adapter Configuration
46
8.3 Transport Configuration
As noted earlier, depending on the version of OpenOCD you use, and the debug adapter
you are using, several transports may be available to communicate with debug targets (or
perhaps to program flash memory).
[Command]
displays the names of the transports supported by this version of OpenOCD.
transport list
transport select transport name
[Command]
Select which of the supported transports to use in this OpenOCD session. The
transport must be supported by the debug adapter hardware and by the version
of OPenOCD you are using (including the adapter’s driver). No arguments: returns
name of session’s selected transport.
8.3.1 JTAG Transport
JTAG is the original transport supported by OpenOCD, and most of the OpenOCD commands support it. JTAG transports expose a chain of one or more Test Access Points
(TAPs), each of which must be explicitly declared. JTAG supports both debugging and
boundary scan testing. Flash programming support is built on top of debug support.
8.3.2 SWD Transport
SWD (Serial Wire Debug) is an ARM-specific transport which exposes one Debug Access
Point (DAP, which must be explicitly declared. (SWD uses fewer signal wires than JTAG.)
SWD is debug-oriented, and does not support boundary scan testing. Flash programming
support is built on top of debug support. (Some processors support both JTAG and SWD.)
swd newdap ...
[Command]
Declares a single DAP which uses SWD transport. Parameters are currently the same
as "jtag newtap" but this is expected to change.
[Command]
Updates TRN (turnaraound delay) and prescaling.fields of the Wire Control Register
(WCR). No parameters: displays current settings.
swd wcr trn prescale
8.3.3 SPI Transport
The Serial Peripheral Interface (SPI) is a general purpose transport which uses four wire
signaling. Some processors use it as part of a solution for flash programming.
8.4 JTAG Speed
JTAG clock setup is part of system setup. It does not belong with interface setup since any
interface only knows a few of the constraints for the JTAG clock speed. Sometimes the JTAG
speed is changed during the target initialization process: (1) slow at reset, (2) program the
CPU clocks, (3) run fast. Both the "slow" and "fast" clock rates are functions of the
oscillators used, the chip, the board design, and sometimes power management software
that may be active.
The speed used during reset, and the scan chain verification which follows reset, can be
adjusted using a reset-start target event handler. It can then be reconfigured to a
Chapter 8: Debug Adapter Configuration
47
faster speed by a reset-init target event handler after it reprograms those CPU clocks,
or manually (if something else, such as a boot loader, sets up those clocks). See [Target
Events], page 64. When the initial low JTAG speed is a chip characteristic, perhaps because
of a required oscillator speed, provide such a handler in the target config file. When that
speed is a function of a board-specific characteristic such as which speed oscillator is used,
it belongs in the board config file instead. In both cases it’s safest to also set the initial
JTAG clock rate to that same slow speed, so that OpenOCD never starts up using a clock
speed that’s faster than the scan chain can support.
jtag_rclk 3000
$_TARGET.cpu configure -event reset-start { jtag_rclk 3000 }
If your system supports adaptive clocking (RTCK), configuring JTAG to use that is probably
the most robust approach. However, it introduces delays to synchronize clocks; so it may
not be the fastest solution.
NOTE: Script writers should consider using jtag_rclk instead of adapter_khz, but only
for (ARM) cores and boards which support adaptive clocking.
adapter_khz max speed kHz
[Command]
A non-zero speed is in KHZ. Hence: 3000 is 3mhz. JTAG interfaces usually support
a limited number of speeds. The speed actually used won’t be faster than the speed
specified.
Chip data sheets generally include a top JTAG clock rate. The actual rate is often a
function of a CPU core clock, and is normally less than that peak rate. For example,
most ARM cores accept at most one sixth of the CPU clock.
Speed 0 (khz) selects RTCK method. See [FAQ RTCK], page 120. If your system uses
RTCK, you won’t need to change the JTAG clocking after setup. Not all interfaces,
boards, or targets support “rtck”. If the interface device can not support it, an error
is returned when you try to use RTCK.
jtag_rclk fallback speed kHz
[Function]
This Tcl proc (defined in ‘startup.tcl’) attempts to enable RTCK/RCLK. If that
fails (maybe the interface, board, or target doesn’t support it), falls back to the
specified frequency.
# Fall back to 3mhz if RTCK is not supported
jtag_rclk 3000
Chapter 9: Reset Configuration
48
9 Reset Configuration
Every system configuration may require a different reset configuration. This can also be
quite confusing. Resets also interact with reset-init event handlers, which do things like
setting up clocks and DRAM, and JTAG clock rates. (See [JTAG Speed], page 46.) They
can also interact with JTAG routers. Please see the various board files for examples.
Note: To maintainers and integrators: Reset configuration touches several
things at once. Normally the board configuration file should define it and assume that the JTAG adapter supports everything that’s wired up to the board’s
JTAG connector.
However, the target configuration file could also make note of something the silicon vendor has done inside the chip, which will be true for most (or all) boards
using that chip. And when the JTAG adapter doesn’t support everything,
the user configuration file will need to override parts of the reset configuration
provided by other files.
9.1 Types of Reset
There are many kinds of reset possible through JTAG, but they may not all work with a
given board and adapter. That’s part of why reset configuration can be error prone.
• System Reset ... the SRST hardware signal resets all chips connected to the JTAG
adapter, such as processors, power management chips, and I/O controllers. Normally
resets triggered with this signal behave exactly like pressing a RESET button.
• JTAG TAP Reset ... the TRST hardware signal resets just the TAP controllers connected to the JTAG adapter. Such resets should not be visible to the rest of the system;
resetting a device’s TAP controller just puts that controller into a known state.
• Emulation Reset ... many devices can be reset through JTAG commands. These resets
are often distinguishable from system resets, either explicitly (a "reset reason" register
says so) or implicitly (not all parts of the chip get reset).
• Other Resets ... system-on-chip devices often support several other types of reset.
You may need to arrange that a watchdog timer stops while debugging, preventing a
watchdog reset. There may be individual module resets.
In the best case, OpenOCD can hold SRST, then reset the TAPs via TRST and send
commands through JTAG to halt the CPU at the reset vector before the 1st instruction
is executed. Then when it finally releases the SRST signal, the system is halted under
debugger control before any code has executed. This is the behavior required to support
the reset halt and reset init commands; after reset init a board-specific script might
do things like setting up DRAM. (See [Reset Command], page 92.)
9.2 SRST and TRST Issues
Because SRST and TRST are hardware signals, they can have a variety of system-specific
constraints. Some of the most common issues are:
• Signal not available ... Some boards don’t wire SRST or TRST to the JTAG connector.
Some JTAG adapters don’t support such signals even if they are wired up. Use the
reset_config signals options to say when either of those signals is not connected.
Chapter 9: Reset Configuration
49
When SRST is not available, your code might not be able to rely on controllers having
been fully reset during code startup. Missing TRST is not a problem, since JTAG-level
resets can be triggered using with TMS signaling.
• Signals shorted ... Sometimes a chip, board, or adapter will connect SRST to TRST,
instead of keeping them separate. Use the reset_config combination options to say
when those signals aren’t properly independent.
• Timing ... Reset circuitry like a resistor/capacitor delay circuit, reset supervisor, or
on-chip features can extend the effect of a JTAG adapter’s reset for some time after
the adapter stops issuing the reset. For example, there may be chip or board requirements that all reset pulses last for at least a certain amount of time; and reset
buttons commonly have hardware debouncing. Use the adapter_nsrst_delay and
jtag_ntrst_delay commands to say when extra delays are needed.
• Drive type ... Reset lines often have a pullup resistor, letting the JTAG interface
treat them as open-drain signals. But that’s not a requirement, so the adapter may
need to use push/pull output drivers. Also, with weak pullups it may be advisable to
drive signals to both levels (push/pull) to minimize rise times. Use the reset_config
trst type and srst type parameters to say how to drive reset signals.
• Special initialization ... Targets sometimes need special JTAG initialization sequences
to handle chip-specific issues (not limited to errata). For example, certain JTAG commands might need to be issued while the system as a whole is in a reset state (SRST
active) but the JTAG scan chain is usable (TRST inactive). Many systems treat combined assertion of SRST and TRST as a trigger for a harder reset than SRST alone.
Such custom reset handling is discussed later in this chapter.
There can also be other issues. Some devices don’t fully conform to the JTAG specifications.
Trivial system-specific differences are common, such as SRST and TRST using slightly
different names. There are also vendors who distribute key JTAG documentation for their
chips only to developers who have signed a Non-Disclosure Agreement (NDA).
Sometimes there are chip-specific extensions like a requirement to use the normally-optional
TRST signal (precluding use of JTAG adapters which don’t pass TRST through), or needing
extra steps to complete a TAP reset.
In short, SRST and especially TRST handling may be very finicky, needing to cope with
both architecture and board specific constraints.
9.3 Commands for Handling Resets
adapter_nsrst_assert_width milliseconds
[Command]
Minimum amount of time (in milliseconds) OpenOCD should wait after asserting
nSRST (active-low system reset) before allowing it to be deasserted.
adapter_nsrst_delay milliseconds
[Command]
How long (in milliseconds) OpenOCD should wait after deasserting nSRST (activelow system reset) before starting new JTAG operations. When a board has a reset
button connected to SRST line it will probably have hardware debouncing, implying
you should use this.
Chapter 9: Reset Configuration
50
jtag_ntrst_assert_width milliseconds
[Command]
Minimum amount of time (in milliseconds) OpenOCD should wait after asserting
nTRST (active-low JTAG TAP reset) before allowing it to be deasserted.
jtag_ntrst_delay milliseconds
[Command]
How long (in milliseconds) OpenOCD should wait after deasserting nTRST (activelow JTAG TAP reset) before starting new JTAG operations.
reset_config mode flag ...
[Command]
This command displays or modifies the reset configuration of your combination of
JTAG board and target in target configuration scripts.
Information earlier in this section describes the kind of problems the command is
intended to address (see [SRST and TRST Issues], page 48). As a rule this command
belongs only in board config files, describing issues like board doesn’t connect TRST ;
or in user config files, addressing limitations derived from a particular combination
of interface and board. (An unlikely example would be using a TRST-only adapter
with a board that only wires up SRST.)
The mode flag options can be specified in any order, but only one of each type –
signals, combination, gates, trst type, and srst type – may be specified at a time.
If you don’t provide a new value for a given type, its previous value (perhaps the
default) is unchanged. For example, this means that you don’t need to say anything
at all about TRST just to declare that if the JTAG adapter should want to drive
SRST, it must explicitly be driven high (‘srst_push_pull’).
• signals can specify which of the reset signals are connected. For example, If
the JTAG interface provides SRST, but the board doesn’t connect that signal
properly, then OpenOCD can’t use it. Possible values are ‘none’ (the default),
‘trst_only’, ‘srst_only’ and ‘trst_and_srst’.
Tip: If your board provides SRST and/or TRST through the JTAG
connector, you must declare that so those signals can be used.
• The combination is an optional value specifying broken reset signal implementations. The default behaviour if no option given is ‘separate’, indicating everything behaves normally. ‘srst_pulls_trst’ states that the test logic is reset
together with the reset of the system (e.g. NXP LPC2000, "broken" board layout), ‘trst_pulls_srst’ says that the system is reset together with the test logic
(only hypothetical, I haven’t seen hardware with such a bug, and can be worked
around). ‘combined’ implies both ‘srst_pulls_trst’ and ‘trst_pulls_srst’.
• The gates tokens control flags that describe some cases where JTAG may be
unvailable during reset. ‘srst_gates_jtag’ (default) indicates that asserting
SRST gates the JTAG clock. This means that no communication can happen
on JTAG while SRST is asserted. Its converse is ‘srst_nogate’, indicating that
JTAG commands can safely be issued while SRST is active.
The optional trst type and srst type parameters allow the driver mode of each reset
line to be specified. These values only affect JTAG interfaces with support for different
driver modes, like the Amontec JTAGkey and JTAG Accelerator. Also, they are
necessarily ignored if the relevant signal (TRST or SRST) is not connected.
Chapter 9: Reset Configuration
51
• Possible trst type driver modes for the test reset signal (TRST) are the default
‘trst_push_pull’, and ‘trst_open_drain’. Most boards connect this signal to
a pulldown, so the JTAG TAPs never leave reset unless they are hooked up to a
JTAG adapter.
• Possible srst type driver modes for the system reset signal (SRST) are the default
‘srst_open_drain’, and ‘srst_push_pull’. Most boards connect this signal to
a pullup, and allow the signal to be pulled low by various events including system
powerup and pressing a reset button.
9.4 Custom Reset Handling
OpenOCD has several ways to help support the various reset mechanisms provided by chip
and board vendors. The commands shown in the previous section give standard parameters.
There are also event handlers associated with TAPs or Targets. Those handlers are Tcl
procedures you can provide, which are invoked at particular points in the reset sequence.
When SRST is not an option you must set up a reset-assert event handler for your
target. For example, some JTAG adapters don’t include the SRST signal; and some boards
have multiple targets, and you won’t always want to reset everything at once.
After configuring those mechanisms, you might still find your board doesn’t start up or
reset correctly. For example, maybe it needs a slightly different sequence of SRST and/or
TRST manipulations, because of quirks that the reset_config mechanism doesn’t address;
or asserting both might trigger a stronger reset, which needs special attention.
Experiment with lower level operations, such as jtag_reset and the jtag arp_* operations
shown here, to find a sequence of operations that works. See Chapter 17 [JTAG Commands],
page 109. When you find a working sequence, it can be used to override jtag_init, which
fires during OpenOCD startup (see [Configuration Stage], page 34); or init_reset, which
fires during reset processing.
You might also want to provide some project-specific reset schemes. For example, on a
multi-target board the standard reset command would reset all targets, but you may need
the ability to reset only one target at time and thus want to avoid using the board-wide
SRST signal.
init_reset mode
[Overridable Procedure]
This is invoked near the beginning of the reset command, usually to provide as much
of a cold (power-up) reset as practical. By default it is also invoked from jtag_init
if the scan chain does not respond to pure JTAG operations. The mode parameter is
the parameter given to the low level reset command (‘halt’, ‘init’, or ‘run’), ‘setup’,
or potentially some other value.
The default implementation just invokes jtag arp_init-reset. Replacements will
normally build on low level JTAG operations such as jtag_reset. Operations here
must not address individual TAPs (or their associated targets) until the JTAG scan
chain has first been verified to work.
Implementations must have verified the JTAG scan chain before they return. This is
done by calling jtag arp_init (or jtag arp_init-reset).
Chapter 9: Reset Configuration
52
[Command]
This validates the scan chain using just the four standard JTAG signals (TMS, TCK,
TDI, TDO). It starts by issuing a JTAG-only reset. Then it performs checks to verify
that the scan chain configuration matches the TAPs it can observe. Those checks
include checking IDCODE values for each active TAP, and verifying the length of
their instruction registers using TAP -ircapture and -irmask values. If these tests
all pass, TAP setup events are issued to all TAPs with handlers for that event.
jtag arp_init
[Command]
This uses TRST and SRST to try resetting everything on the JTAG scan chain (and
anything else connected to SRST). It then invokes the logic of jtag arp_init.
jtag arp_init-reset
Chapter 10: TAP Declaration
53
10 TAP Declaration
Test Access Ports (TAPs) are the core of JTAG. TAPs serve many roles, including:
• Debug Target A CPU TAP can be used as a GDB debug target
• Flash Programing Some chips program the flash directly via JTAG. Others do it indirectly, making a CPU do it.
• Program Download Using the same CPU support GDB uses, you can initialize a DRAM
controller, download code to DRAM, and then start running that code.
• Boundary Scan Most chips support boundary scan, which helps test for board assembly
problems like solder bridges and missing connections
OpenOCD must know about the active TAPs on your board(s). Setting up the TAPs is
the core task of your configuration files. Once those TAPs are set up, you can pass their
names to code which sets up CPUs and exports them as GDB targets, probes flash memory,
performs low-level JTAG operations, and more.
10.1 Scan Chains
TAPs are part of a hardware scan chain, which is daisy chain of TAPs. They also need to
be added to OpenOCD’s software mirror of that hardware list, giving each member a name
and associating other data with it. Simple scan chains, with a single TAP, are common
in systems with a single microcontroller or microprocessor. More complex chips may have
several TAPs internally. Very complex scan chains might have a dozen or more TAPs:
several in one chip, more in the next, and connecting to other boards with their own chips
and TAPs.
You can display the list with the scan_chain command. (Don’t confuse this with the list
displayed by the targets command, presented in the next chapter. That only displays
TAPs for CPUs which are configured as debugging targets.) Here’s what the scan chain
might look like for a chip more than one TAP:
TapName
Enabled IdCode
Expected
IrLen IrCap IrMask
-- ------------------ ------- ---------- ---------- ----- ----- -----0 omap5912.dsp
Y
0x03df1d81 0x03df1d81
38 0x01 0x03
1 omap5912.arm
Y
0x0692602f 0x0692602f
4 0x01 0x0f
2 omap5912.unknown
Y
0x00000000 0x00000000
8 0x01 0x03
OpenOCD can detect some of that information, but not all of it. See [Autoprobing], page 57.
Unfortunately those TAPs can’t always be autoconfigured, because not all devices provide
good support for that. JTAG doesn’t require supporting IDCODE instructions, and chips
with JTAG routers may not link TAPs into the chain until they are told to do so.
The configuration mechanism currently supported by OpenOCD requires explicit configuration of all TAP devices using jtag newtap commands, as detailed later in this chapter.
A command like this would declare one tap and name it chip1.cpu:
jtag newtap chip1 cpu -irlen 4 -expected-id 0x3ba00477
Each target configuration file lists the TAPs provided by a given chip. Board configuration
files combine all the targets on a board, and so forth. Note that the order in which TAPs
are declared is very important. It must match the order in the JTAG scan chain, both inside
a single chip and between them. See [FAQ TAP Order], page 123.
Chapter 10: TAP Declaration
54
For example, the ST Microsystems STR912 chip has three separate TAPs1 . To configure
those taps, ‘target/str912.cfg’ includes commands something like this:
jtag newtap str912 flash ... params ...
jtag newtap str912 cpu ... params ...
jtag newtap str912 bs ... params ...
Actual config files use a variable instead of literals like ‘str912’, to support more than one
chip of each type. See Chapter 6 [Config File Guidelines], page 20.
[Command]
Returns the names of all current TAPs in the scan chain. Use jtag cget or jtag
tapisenabled to examine attributes and state of each TAP.
foreach t [jtag names] {
puts [format "TAP: %s\n" $t]
}
jtag names
[Command]
Displays the TAPs in the scan chain configuration, and their status. The set of TAPs
listed by this command is fixed by exiting the OpenOCD configuration stage, but
systems with a JTAG router can enable or disable TAPs dynamically.
scan_chain
10.2 TAP Names
When TAP objects are declared with jtag newtap, a dotted.name is created for the TAP,
combining the name of a module (usually a chip) and a label for the TAP. For example: xilinx.tap, str912.flash, omap3530.jrc, dm6446.dsp, or stm32.cpu. Many other
commands use that dotted.name to manipulate or refer to the TAP. For example, CPU
configuration uses the name, as does declaration of NAND or NOR flash banks.
The components of a dotted name should follow “C” symbol name rules: start with an
alphabetic character, then numbers and underscores are OK; while others (including dots!)
are not.
Tip: In older code, JTAG TAPs were numbered from 0..N. This feature is
still present. However its use is highly discouraged, and should not be relied
on; it will be removed by mid-2010. Update all of your scripts to use TAP
names rather than numbers, by paying attention to the runtime warnings they
trigger. Using TAP numbers in target configuration scripts prevents reusing
those scripts on boards with multiple targets.
10.3 TAP Declaration Commands
jtag newtap chipname tapname configparams...
[Command]
Declares a new TAP with the dotted name chipname.tapname, and configured according to the various configparams.
The chipname is a symbolic name for the chip. Conventionally target config files use
$_CHIPNAME, defaulting to the model name given by the chip vendor but overridable.
The tapname reflects the role of that TAP, and should follow this convention:
1
See the ST document titled: STR91xFAxxx, Section 3.15 Jtag Interface, Page: 28/102, Figure 3: JTAG
chaining inside the STR91xFA. http://eu.st.com/stonline/products/literature/ds/13495.pdf
Chapter 10: TAP Declaration
55
• bs – For boundary scan if this is a seperate TAP;
• cpu – The main CPU of the chip, alternatively arm and dsp on chips with both
ARM and DSP CPUs, arm1 and arm2 on chips two ARMs, and so forth;
• etb – For an embedded trace buffer (example: an ARM ETB11);
• flash – If the chip has a flash TAP, like the str912;
• jrc – For JTAG route controller (example: the ICEpick modules on many Texas
Instruments chips, like the OMAP3530 on Beagleboards);
• tap – Should be used only FPGA or CPLD like devices with a single TAP;
• unknownN – If you have no idea what the TAP is for (N is a number);
• when in doubt – Use the chip maker’s name in their data sheet. For example,
the Freescale IMX31 has a SDMA (Smart DMA) with a JTAG TAP; that TAP
should be named sdma.
Every TAP requires at least the following configparams:
• -irlen NUMBER
The length in bits of the instruction register, such as 4 or 5 bits.
A TAP may also provide optional configparams:
• -disable (or -enable)
Use the -disable parameter to flag a TAP which is not linked in to the scan
chain after a reset using either TRST or the JTAG state machine’s reset state.
You may use -enable to highlight the default state (the TAP is linked in). See
[Enabling and Disabling TAPs], page 56.
• -expected-id number
A non-zero number represents a 32-bit IDCODE which you expect to find when
the scan chain is examined. These codes are not required by all JTAG devices.
Repeat the option as many times as required if more than one ID code could
appear (for example, multiple versions). Specify number as zero to suppress
warnings about IDCODE values that were found but not included in the list.
Provide this value if at all possible, since it lets OpenOCD tell when the scan chain
it sees isn’t right. These values are provided in vendors’ chip documentation,
usually a technical reference manual. Sometimes you may need to probe the
JTAG hardware to find these values. See [Autoprobing], page 57.
• -ignore-version
Specify this to ignore the JTAG version field in the -expected-id option. When
vendors put out multiple versions of a chip, or use the same JTAG-level ID for
several largely-compatible chips, it may be more practical to ignore the version
field than to update config files to handle all of the various chip IDs. The version
field is defined as bit 28-31 of the IDCODE.
• -ircapture NUMBER
The bit pattern loaded by the TAP into the JTAG shift register on entry to the
ircapture state, such as 0x01. JTAG requires the two LSBs of this value to
be 01. By default, -ircapture and -irmask are set up to verify that two-bit
value. You may provide additional bits, if you know them, or indicate that a
TAP doesn’t conform to the JTAG specification.
Chapter 10: TAP Declaration
56
• -irmask NUMBER
A mask used with -ircapture to verify that instruction scans work correctly.
Such scans are not used by OpenOCD except to verify that there seems to be no
problems with JTAG scan chain operations.
10.4 Other TAP commands
jtag cget dotted.name ‘-event’ name
jtag configure dotted.name ‘-event’ name string
[Command]
[Command]
At this writing this TAP attribute mechanism is used only for event handling. (It is
not a direct analogue of the cget/configure mechanism for debugger targets.) See
the next section for information about the available events.
The configure subcommand assigns an event handler, a TCL string which is evaluated when the event is triggered. The cget subcommand returns that handler.
10.5 TAP Events
OpenOCD includes two event mechanisms. The one presented here applies to all JTAG
TAPs. The other applies to debugger targets, which are associated with certain TAPs.
The TAP events currently defined are:
• post-reset
The TAP has just completed a JTAG reset. The tap may still be in the JTAG reset
state. Handlers for these events might perform initialization sequences such as issuing
TCK cycles, TMS sequences to ensure exit from the ARM SWD mode, and more.
Because the scan chain has not yet been verified, handlers for these events should not
issue commands which scan the JTAG IR or DR registers of any particular target.
NOTE: As this is written (September 2009), nothing prevents such access.
• setup
The scan chain has been reset and verified. This handler may enable TAPs as needed.
• tap-disable
The TAP needs to be disabled. This handler should implement jtag tapdisable by
issuing the relevant JTAG commands.
• tap-enable
The TAP needs to be enabled. This handler should implement jtag tapenable by
issuing the relevant JTAG commands.
If you need some action after each JTAG reset, which isn’t actually specific to any TAP
(since you can’t yet trust the scan chain’s contents to be accurate), you might:
jtag configure CHIP.jrc -event post-reset {
echo "JTAG Reset done"
... non-scan jtag operations to be done after reset
}
Chapter 10: TAP Declaration
57
10.6 Enabling and Disabling TAPs
In some systems, a JTAG Route Controller (JRC) is used to enable and/or disable specific JTAG TAPs. Many ARM based chips from Texas Instruments include an “ICEpick”
module, which is a JRC. Such chips include DaVinci and OMAP3 processors.
A given TAP may not be visible until the JRC has been told to link it into the scan chain;
and if the JRC has been told to unlink that TAP, it will no longer be visible. Such routers
address problems that JTAG “bypass mode” ignores, such as:
• The scan chain can only go as fast as its slowest TAP.
• Having many TAPs slows instruction scans, since all TAPs receive new instructions.
• TAPs in the scan chain must be powered up, which wastes power and prevents debugging some power management mechanisms.
The IEEE 1149.1 JTAG standard has no concept of a “disabled” tap, as implied by the
existence of JTAG routers. However, the upcoming IEEE 1149.7 framework (layered on top
of JTAG) does include a kind of JTAG router functionality.
In OpenOCD, tap enabling/disabling is invoked by the Tcl commands shown below, and is
implemented using TAP event handlers. So for example, when defining a TAP for a CPU
connected to a JTAG router, your ‘target.cfg’ file should define TAP event handlers using
code that looks something like this:
jtag configure CHIP.cpu -event tap-enable {
... jtag operations using CHIP.jrc
}
jtag configure CHIP.cpu -event tap-disable {
... jtag operations using CHIP.jrc
}
Then you might want that CPU’s TAP enabled almost all the time:
jtag configure $CHIP.jrc -event setup "jtag tapenable $CHIP.cpu"
Note how that particular setup event handler declaration uses quotes to evaluate $CHIP
when the event is configured. Using brackets { } would cause it to be evaluated later, at
runtime, when it might have a different value.
jtag tapdisable dotted.name
[Command]
If necessary, disables the tap by sending it a ‘tap-disable’ event. Returns the string
"1" if the tap specified by dotted.name is enabled, and "0" if it is disabled.
jtag tapenable dotted.name
[Command]
If necessary, enables the tap by sending it a ‘tap-enable’ event. Returns the string
"1" if the tap specified by dotted.name is enabled, and "0" if it is disabled.
jtag tapisenabled dotted.name
[Command]
Returns the string "1" if the tap specified by dotted.name is enabled, and "0" if it is
disabled.
Note: Humans will find the scan_chain command more helpful for querying the state of the JTAG taps.
Chapter 10: TAP Declaration
58
10.7 Autoprobing
TAP configuration is the first thing that needs to be done after interface and reset configuration. Sometimes it’s hard finding out what TAPs exist, or how they are identified.
Vendor documentation is not always easy to find and use.
To help you get past such problems, OpenOCD has a limited autoprobing ability to look at
the scan chain, doing a blind interrogation and then reporting the TAPs it finds. To use this
mechanism, start the OpenOCD server with only data that configures your JTAG interface,
and arranges to come up with a slow clock (many devices don’t support fast JTAG clocks
right when they come out of reset).
For example, your ‘openocd.cfg’ file might have:
source [find interface/olimex-arm-usb-tiny-h.cfg]
reset_config trst_and_srst
jtag_rclk 8
When you start the server without any TAPs configured, it will attempt to autoconfigure
the TAPs. There are two parts to this:
1. TAP discovery ... After a JTAG reset (sometimes a system reset may be needed too),
each TAP’s data registers will hold the contents of either the IDCODE or BYPASS
register. If JTAG communication is working, OpenOCD will see each TAP, and report
what ‘-expected-id’ to use with it.
2. IR Length discovery ... Unfortunately JTAG does not provide a reliable way to find out
the value of the ‘-irlen’ parameter to use with a TAP that is discovered. If OpenOCD
can discover the length of a TAP’s instruction register, it will report it. Otherwise you
may need to consult vendor documentation, such as chip data sheets or BSDL files.
In many cases your board will have a simple scan chain with just a single device. Here’s
what OpenOCD reported with one board that’s a bit more complex:
clock speed 8 kHz
There are no enabled taps. AUTO PROBING MIGHT NOT WORK!!
AUTO auto0.tap - use "jtag newtap auto0 tap -expected-id 0x2b900f0f ..."
AUTO auto1.tap - use "jtag newtap auto1 tap -expected-id 0x07926001 ..."
AUTO auto2.tap - use "jtag newtap auto2 tap -expected-id 0x0b73b02f ..."
AUTO auto0.tap - use "... -irlen 4"
AUTO auto1.tap - use "... -irlen 4"
AUTO auto2.tap - use "... -irlen 6"
no gdb ports allocated as no target has been specified
Given that information, you should be able to either find some existing config files to use,
or create your own. If you create your own, you would configure from the bottom up: first
a ‘target.cfg’ file with these TAPs, any targets associated with them, and any on-chip
resources; then a ‘board.cfg’ with off-chip resources, clocking, and so forth.
Chapter 11: CPU Configuration
59
11 CPU Configuration
This chapter discusses how to set up GDB debug targets for CPUs. You can also access
these targets without GDB (see Chapter 16 [Architecture and Core Commands], page 96,
and [Target State handling], page 91) and through various kinds of NAND and NOR flash
commands. If you have multiple CPUs you can have multiple such targets.
We’ll start by looking at how to examine the targets you have, then look at how to add one
more target and how to configure it.
11.1 Target List
All targets that have been set up are part of a list, where each member has a name. That
name should normally be the same as the TAP name. You can display the list with the
targets (plural!) command. This display often has only one CPU; here’s what it might
look like with more than one:
TargetName
-- -----------------0* at91rm9200.cpu
1 MyTarget
Type
---------arm920t
cortex_m3
Endian
-----little
little
TapName
-----------------at91rm9200.cpu
mychip.foo
State
-----------running
tap-disabled
One member of that list is the current target, which is implicitly referenced by many
commands. It’s the one marked with a * near the target name. In particular, memory
addresses often refer to the address space seen by that current target. Commands like mdw
(memory display words) and flash erase_address (erase NOR flash blocks) are examples;
and there are many more.
Several commands let you examine the list of targets:
[Command]
Note: target numbers are deprecated; don’t use them. They will be removed shortly
after August 2010, including this command. Iterate target using target names, not
by counting.
target count
Returns the number of targets, N . The highest numbered target is N − 1.
set c [target count]
for { set x 0 } { $x < $c } { incr x } {
# Assuming you have created this function
print_target_details $x
}
target current
[Command]
Returns the name of the current target.
target names
Lists the names of all current targets in the list.
foreach t [target names] {
puts [format "Target: %s\n" $t]
}
[Command]
Chapter 11: CPU Configuration
60
target number number
[Command]
Note: target numbers are deprecated; don’t use them. They will be removed shortly
after August 2010, including this command.
The list of targets is numbered starting at zero. This command returns the name of
the target at index number.
set thename [target number $x]
puts [format "Target %d is: %s\n" $x $thename]
targets [name]
[Command]
Note: the name of this command is plural. Other target command names are singular.
With no parameter, this command displays a table of all known targets in a user
friendly form.
With a parameter, this command sets the current target to the given target with the
given name; this is only relevant on boards which have more than one target.
11.2 Target CPU Types and Variants
Each target has a CPU type, as shown in the output of the targets command. You need
to specify that type when calling target create. The CPU type indicates more than just
the instruction set. It also indicates how that instruction set is implemented, what kind
of debug support it integrates, whether it has an MMU (and if so, what kind), what corespecific commands may be available (see Chapter 16 [Architecture and Core Commands],
page 96), and more.
For some CPU types, OpenOCD also defines variants which indicate differences that affect
their handling. For example, a particular implementation bug might need to be worked
around in some chip versions.
It’s easy to see what target types are supported, since there’s a command to list them.
However, there is currently no way to list what target variants are supported (other than
by reading the OpenOCD source code).
[Command]
Lists all supported target types. At this writing, the supported CPU types and
variants are:
• arm11 – this is a generation of ARMv6 cores
• arm720t – this is an ARMv4 core with an MMU
• arm7tdmi – this is an ARMv4 core
• arm920t – this is an ARMv4 core with an MMU
• arm926ejs – this is an ARMv5 core with an MMU
• arm966e – this is an ARMv5 core
• arm9tdmi – this is an ARMv4 core
• avr – implements Atmel’s 8-bit AVR instruction set. (Support for this is preliminary and incomplete.)
• cortex_a8 – this is an ARMv7 core with an MMU
• cortex_m3 – this is an ARMv7 core, supporting only the compact Thumb2 instruction set.
target types
Chapter 11: CPU Configuration
61
• dragonite – resembles arm966e
• dsp563xx – implements Freescale’s 24-bit DSP. (Support for this is still incomplete.)
• fa526 – resembles arm920 (w/o Thumb)
• feroceon – resembles arm926
• mips_m4k – a MIPS core. This supports one variant:
• xscale – this is actually an architecture, not a CPU type. It is based on the
ARMv5 architecture. There are several variants defined:
− ixp42x, ixp45x, ixp46x, pxa27x ... instruction register length is 7 bits
− pxa250, pxa255, pxa26x ... instruction register length is 5 bits
− pxa3xx ... instruction register length is 11 bits
To avoid being confused by the variety of ARM based cores, remember this key point:
ARM is a technology licencing company. (See: http://www.arm.com.) The CPU name
used by OpenOCD will reflect the CPU design that was licenced, not a vendor brand which
incorporates that design. Name prefixes like arm7, arm9, arm11, and cortex reflect design
generations; while names like ARMv4, ARMv5, ARMv6, and ARMv7 reflect an architecture
version implemented by a CPU design.
11.3 Target Configuration
Before creating a “target”, you must have added its TAP to the scan chain. When you’ve
added that TAP, you will have a dotted.name which is used to set up the CPU support.
The chip-specific configuration file will normally configure its CPU(s) right after it adds all
of the chip’s TAPs to the scan chain.
Although you can set up a target in one step, it’s often clearer if you use shorter commands
and do it in two steps: create it, then configure optional parts. All operations on the target
after it’s created will use a new command, created as part of target creation.
The two main things to configure after target creation are a work area, which usually has
target-specific defaults even if the board setup code overrides them later; and event handlers
(see [Target Events], page 64), which tend to be much more board-specific. The key steps
you use might look something like this
target create MyTarget cortex_m3 -chain-position mychip.cpu
$MyTarget configure -work-area-phys 0x08000 -work-area-size 8096
$MyTarget configure -event reset-deassert-pre { jtag_rclk 5 }
$MyTarget configure -event reset-init { myboard_reinit }
You should specify a working area if you can; typically it uses some on-chip SRAM. Such
a working area can speed up many things, including bulk writes to target memory; flash
operations like checking to see if memory needs to be erased; GDB memory checksumming;
and more.
Warning: On more complex chips, the work area can become inaccessible when
application code (such as an operating system) enables or disables the MMU.
For example, the particular MMU context used to acess the virtual address
will probably matter ... and that context might not have easy access to other
Chapter 11: CPU Configuration
62
addresses needed. At this writing, OpenOCD doesn’t have much MMU intelligence.
It’s often very useful to define a reset-init event handler. For systems that are normally
used with a boot loader, common tasks include updating clocks and initializing memory
controllers. That may be needed to let you write the boot loader into flash, in order to
“de-brick” your board; or to load programs into external DDR memory without having run
the boot loader.
target create target name type configparams...
[Command]
This command creates a GDB debug target that refers to a specific JTAG tap. It
enters that target into a list, and creates a new command (target_name) which is
used for various purposes including additional configuration.
• target name ... is the name of the debug target. By convention this should be
the same as the dotted.name of the TAP associated with this target, which must
be specified here using the -chain-position dotted.name configparam.
This name is also used to create the target object command, referred to here as
$target_name, and in other places the target needs to be identified.
• type ... specifies the target type. See [target types], page 60.
• configparams ... all parameters accepted by $target_name configure are permitted. If the target is big-endian, set it here with -endian big. If the variant
matters, set it here with -variant.
You must set the -chain-position dotted.name here.
$target_name configure configparams...
[Command]
The options accepted by this command may also be specified as parameters to target
create. Their values can later be queried one at a time by using the $target_name
cget command.
Warning: changing some of these after setup is dangerous. For example, moving a
target from one TAP to another; and changing its endianness or variant.
• -chain-position dotted.name – names the TAP used to access this target.
• -endian (‘big’|‘little’) – specifies whether the CPU uses big or little endian
conventions
• -event event name event body – See [Target Events], page 64. Note that this
updates a list of named event handlers. Calling this twice with two different
event names assigns two different handlers, but calling it twice with the same
event name assigns only one handler.
• -variant name – specifies a variant of the target, which OpenOCD needs to
know about.
• -work-area-backup (‘0’|‘1’) – says whether the work area gets backed up; by
default, it is not backed up. When possible, use a working area that doesn’t need
to be backed up, since performing a backup slows down operations. For example,
the beginning of an SRAM block is likely to be used by most build systems, but
the end is often unused.
• -work-area-size size – specify work are size, in bytes. The same size applies
regardless of whether its physical or virtual address is being used.
Chapter 11: CPU Configuration
63
• -work-area-phys address – set the work area base address to be used when no
MMU is active.
• -work-area-virt address – set the work area base address to be used when an
MMU is active. Do not specify a value for this except on targets with an MMU.
The value should normally correspond to a static mapping for the -work-areaphys address, set up by the current operating system.
• -rtos rtos type – enable rtos support for target, rtos type can be one of
‘auto’|‘eCos’|‘ThreadX’| ‘FreeRTOS’|‘linux’.
11.4 Other $target name Commands
The Tcl/Tk language has the concept of object commands, and OpenOCD adopts that
same model for targets.
A good Tk example is a on screen button. Once a button is created a button has a name
(a path in Tk terms) and that name is useable as a first class command. For example in
Tk, one can create a button and later configure it like this:
# Create
button .foobar -background red -command { foo }
# Modify
.foobar configure -foreground blue
# Query
set x [.foobar cget -background]
# Report
puts [format "The button is %s" $x]
In OpenOCD’s terms, the “target” is an object just like a Tcl/Tk button, and its object
commands are invoked the same way.
str912.cpu
mww 0x1234 0x42
omap3530.cpu mww 0x5555 123
The commands supported by OpenOCD target objects are:
[Command]
[Command]
[Command]
[Command]
[Command]
Internal OpenOCD scripts (most notably ‘startup.tcl’) use these to deal with specific reset cases. They are not otherwise documented here.
$target_name
$target_name
$target_name
$target_name
$target_name
arp_examine
arp_halt
arp_poll
arp_reset
arp_waitstate
$target_name array2mem arrayname width address count
$target_name mem2array arrayname width address count
[Command]
[Command]
These provide an efficient script-oriented interface to memory. The array2mem primitive writes bytes, halfwords, or words; while mem2array reads them. In both cases,
the TCL side uses an array, and the target side uses raw memory.
The efficiency comes from enabling the use of bulk JTAG data transfer operations.
The script orientation comes from working with data values that are packaged for use
by TCL scripts; mdw type primitives only print data they retrieve, and neither store
nor return those values.
Chapter 11: CPU Configuration
64
• arrayname ... is the name of an array variable
• width ... is 8/16/32 - indicating the memory access size
• address ... is the target memory address
• count ... is the number of elements to process
$target_name cget queryparm
[Command]
Each configuration parameter accepted by $target_name configure can be individually queried, to return its current value. The queryparm is a parameter name accepted
by that command, such as -work-area-phys. There are a few special cases:
• -event event name – returns the handler for the event named event name. This
is a special case because setting a handler requires two parameters.
• -type – returns the target type. This is a special case because this is set using
target create and can’t be changed using $target_name configure.
For example, if you wanted to summarize information about all the targets you might
use something like this:
foreach name [target names] {
set y [$name cget -endian]
set z [$name cget -type]
puts [format "Chip %d is %s, Endian: %s, type: %s" \
$x $name $y $z]
}
[Command]
Displays the current target state: debug-running, halted, reset, running, or
unknown. (Also, see [Event Polling], page 36.)
$target_name curstate
[Command]
Displays a table listing all event handlers currently associated with this target. See
[Target Events], page 64.
$target_name eventlist
$target_name invoke-event event name
[Command]
Invokes the handler for the event named event name. (This is primarily intended for
use by OpenOCD framework code, for example by the reset code in ‘startup.tcl’.)
$target_name mdw addr [count]
$target_name mdh addr [count]
$target_name mdb addr [count]
[Command]
[Command]
[Command]
Display contents of address addr, as 32-bit words (mdw), 16-bit halfwords (mdh), or
8-bit bytes (mdb). If count is specified, displays that many units. (If you want to
manipulate the data instead of displaying it, see the mem2array primitives.)
$target_name mww addr word
$target_name mwh addr halfword
$target_name mwb addr byte
[Command]
[Command]
[Command]
Writes the specified word (32 bits), halfword (16 bits), or byte (8-bit) pattern, at the
specified address addr.
Chapter 11: CPU Configuration
65
11.5 Target Events
At various times, certain things can happen, or you want them to happen. For example:
• What should happen when GDB connects? Should your target reset?
• When GDB tries to flash the target, do you need to enable the flash via a special
command?
• Is using SRST appropriate (and possible) on your system? Or instead of that, do you
need to issue JTAG commands to trigger reset? SRST usually resets everything on the
scan chain, which can be inappropriate.
• During reset, do you need to write to certain memory locations to set up system clocks
or to reconfigure the SDRAM? How about configuring the watchdog timer, or other
peripherals, to stop running while you hold the core stopped for debugging?
All of the above items can be addressed by target event handlers. These are set up by
$target_name configure -event or target create ... -event.
The programmer’s model matches the -command option used in Tcl/Tk buttons and events.
The two examples below act the same, but one creates and invokes a small procedure while
the other inlines it.
proc my_attach_proc { } {
echo "Reset..."
reset halt
}
mychip.cpu configure -event gdb-attach my_attach_proc
mychip.cpu configure -event gdb-attach {
echo "Reset..."
# To make flash probe and gdb load to flash work we need a reset init.
reset init
}
The following target events are defined:
• debug-halted
The target has halted for debug reasons (i.e.: breakpoint)
• debug-resumed
The target has resumed (i.e.: gdb said run)
• early-halted
Occurs early in the halt process
• examine-start
Before target examine is called.
• examine-end
After target examine is called with no errors.
• gdb-attach
When GDB connects. This is before any communication with the target, so this can
be used to set up the target so it is possible to probe flash. Probing flash is necessary
during gdb connect if gdb load is to write the image to flash. Another use of the flash
memory map is for GDB to automatically hardware/software breakpoints depending
on whether the breakpoint is in RAM or read only memory.
Chapter 11: CPU Configuration
66
• gdb-detach
When GDB disconnects
• gdb-end
When the target has halted and GDB is not doing anything (see early halt)
• gdb-flash-erase-start
Before the GDB flash process tries to erase the flash
• gdb-flash-erase-end
After the GDB flash process has finished erasing the flash
• gdb-flash-write-start
Before GDB writes to the flash
• gdb-flash-write-end
After GDB writes to the flash
• gdb-start
Before the target steps, gdb is trying to start/resume the target
• halted
The target has halted
• reset-assert-pre
Issued as part of reset processing after reset_init was triggered but before either
SRST alone is re-asserted on the scan chain, or reset-assert is triggered.
• reset-assert
Issued as part of reset processing after reset-assert-pre was triggered. When such a
handler is present, cores which support this event will use it instead of asserting SRST.
This support is essential for debugging with JTAG interfaces which don’t include an
SRST line (JTAG doesn’t require SRST), and for selective reset on scan chains that
have multiple targets.
• reset-assert-post
Issued as part of reset processing after reset-assert has been triggered. or the target
asserted SRST on the entire scan chain.
• reset-deassert-pre
Issued as part of reset processing after reset-assert-post has been triggered.
• reset-deassert-post
Issued as part of reset processing after reset-deassert-pre has been triggered and
(if the target is using it) after SRST has been released on the scan chain.
• reset-end
Issued as the final step in reset processing.
• reset-init
Used by reset init command for board-specific initialization. This event fires after
reset-deassert-post.
This is where you would configure PLLs and clocking, set up DRAM so you can download programs that don’t fit in on-chip SRAM, set up pin multiplexing, and so on.
(You may be able to switch to a fast JTAG clock rate here, after the target clocks are
fully set up.)
• reset-start
Issued as part of reset processing before reset_init is called.
Chapter 11: CPU Configuration
67
This is the most robust place to use jtag_rclk or adapter_khz to switch to a low
JTAG clock rate, when reset disables PLLs needed to use a fast clock.
• resume-start
Before any target is resumed
• resume-end
After all targets have resumed
• resumed
Target has resumed
Chapter 12: Flash Commands
68
12 Flash Commands
OpenOCD has different commands for NOR and NAND flash; the “flash” command works
with NOR flash, while the “nand” command works with NAND flash. This partially reflects
different hardware technologies: NOR flash usually supports direct CPU instruction and
data bus access, while data from a NAND flash must be copied to memory before it can be
used. (SPI flash must also be copied to memory before use.) However, the documentation
also uses “flash” as a generic term; for example, “Put flash configuration in board-specific
files”.
Flash Steps:
1. Configure via the command flash bank
Do this in a board-specific configuration file, passing parameters as needed by the
driver.
2. Operate on the flash via flash subcommand
Often commands to manipulate the flash are typed by a human, or run via a script in
some automated way. Common tasks include writing a boot loader, operating system,
or other data.
3. GDB Flashing
Flashing via GDB requires the flash be configured via “flash bank”, and the GDB flash
features be enabled. See [GDB Configuration], page 35.
Many CPUs have the ablity to “boot” from the first flash bank. This means that misprogramming that bank can “brick” a system, so that it can’t boot. JTAG tools, like
OpenOCD, are often then used to “de-brick” the board by (re)installing working boot
firmware.
12.1 Flash Configuration Commands
flash bank name driver base size chip width bus width target
[driver options]
[Config Command]
Configures a flash bank which provides persistent storage for addresses from base to
base+size−1. These banks will often be visible to GDB through the target’s memory
map. In some cases, configuring a flash bank will activate extra commands; see the
driver-specific documentation.
• name ... may be used to reference the flash bank in other flash commands. A
number is also available.
• driver ... identifies the controller driver associated with the flash bank being declared. This is usually cfi for external flash, or else the name of a microcontroller
with embedded flash memory. See [Flash Driver List], page 71.
• base ... Base address of the flash chip.
• size ... Size of the chip, in bytes. For some drivers, this value is detected from
the hardware.
• chip width ... Width of the flash chip, in bytes; ignored for most microcontroller
drivers.
• bus width ... Width of the data bus used to access the chip, in bytes; ignored
for most microcontroller drivers.
Chapter 12: Flash Commands
69
• target ... Names the target used to issue commands to the flash controller.
• driver options ... drivers may support, or require, additional parameters. See
the driver-specific documentation for more information.
Note: This command is not available after OpenOCD initialization has
completed. Use it in board specific configuration files, not interactively.
[Command]
Prints a one-line summary of each device that was declared using flash bank, numbered from zero. Note that this is the plural form; the singular form is a very different
command.
flash banks
[Command]
Retrieves a list of associative arrays for each device that was declared using flash
bank, numbered from zero. This returned list can be manipulated easily from within
scripts.
flash list
flash probe num
[Command]
Identify the flash, or validate the parameters of the configured flash. Operation
depends on the flash type. The num parameter is a value shown by flash banks.
Most flash commands will implicitly autoprobe the bank; flash drivers can distinguish
between probing and autoprobing, but most don’t bother.
12.2 Erasing, Reading, Writing to Flash
One feature distinguishing NOR flash from NAND or serial flash technologies is that for
read access, it acts exactly like any other addressible memory. This means you can use
normal memory read commands like mdw or dump_image with it, with no special flash
subcommands. See [Memory access], page 93, and [Image access], page 94.
Write access works differently. Flash memory normally needs to be erased before it’s written.
Erasing a sector turns all of its bits to ones, and writing can turn ones into zeroes. This is
why there are special commands for interactive erasing and writing, and why GDB needs
to know which parts of the address space hold NOR flash memory.
Note: Most of these erase and write commands leverage the fact that NOR
flash chips consume target address space. They implicitly refer to the current
JTAG target, and map from an address in that target’s address space back to a
flash bank. A few commands use abstract addressing based on bank and sector
numbers, and don’t depend on searching the current target and its address
space. Avoid confusing the two command models.
Some flash chips implement software protection against accidental writes, since such buggy
writes could in some cases “brick” a system. For such systems, erasing and writing may
require sector protection to be disabled first. Examples include CFI flash such as “Intel
Advanced Bootblock flash”, and AT91SAM7 on-chip flash. See [flash protect], page 71.
flash erase_sector num first last
[Command]
Erase sectors in bank num, starting at sector first up to and including last. Sector
numbering starts at 0. Providing a last sector of ‘last’ specifies "to the end of the
flash bank". The num parameter is a value shown by flash banks.
Chapter 12: Flash Commands
70
flash erase_address [‘pad’] [‘unlock’] address length
[Command]
Erase sectors starting at address for length bytes. Unless ‘pad’ is specified, address
must begin a flash sector, and address + length − 1 must end a sector. Specifying
‘pad’ erases extra data at the beginning and/or end of the specified region, as needed
to erase only full sectors. The flash bank to use is inferred from the address, and the
specified length must stay within that bank. As a special case, when length is zero
and address is the start of the bank, the whole flash is erased. If ‘unlock’ is specified,
then the flash is unprotected before erase starts.
flash fillw address word length
flash fillh address halfword length
flash fillb address byte length
[Command]
[Command]
[Command]
Fills flash memory with the specified word (32 bits), halfword (16 bits), or byte (8-bit)
pattern, starting at address and continuing for length units (word/halfword/byte).
No erasure is done before writing; when needed, that must be done before issuing this
command. Writes are done in blocks of up to 1024 bytes, and each write is verified by
reading back the data and comparing it to what was written. The flash bank to use
is inferred from the address of each block, and the specified length must stay within
that bank.
flash write_bank num filename offset
[Command]
Write the binary ‘filename’ to flash bank num, starting at offset bytes from the
beginning of the bank. The num parameter is a value shown by flash banks.
flash write_image [erase] [unlock] filename [offset] [type]
[Command]
Write the image ‘filename’ to the current target’s flash bank(s). A relocation offset
may be specified, in which case it is added to the base address for each section in the
image. The file [type] can be specified explicitly as ‘bin’ (binary), ‘ihex’ (Intel hex),
‘elf’ (ELF file), ‘s19’ (Motorola s19). ‘mem’, or ‘builder’. The relevant flash sectors
will be erased prior to programming if the ‘erase’ parameter is given. If ‘unlock’
is provided, then the flash banks are unlocked before erase and program. The flash
bank to use is inferred from the address of each image section.
Warning: Be careful using the ‘erase’ flag when the flash is holding data
you want to preserve. Portions of the flash outside those described in the
image’s sections might be erased with no notice.
• When a section of the image being written does not fill out all the
sectors it uses, the unwritten parts of those sectors are necessarily
also erased, because sectors can’t be partially erased.
• Data stored in sector "holes" between image sections are also affected. For example, "flash write_image erase ..." of an image
with one byte at the beginning of a flash bank and one byte at the
end erases the entire bank – not just the two sectors being written.
Also, when flash protection is important, you must re-apply it after it has
been removed by the ‘unlock’ flag.
Chapter 12: Flash Commands
71
12.3 Other Flash commands
flash erase_check num
[Command]
Check erase state of sectors in flash bank num, and display that status. The num
parameter is a value shown by flash banks.
flash info num
[Command]
Print info about flash bank num The num parameter is a value shown by flash
banks. This command will first query the hardware, it does not print cached and
possibly stale information.
flash protect num first last (‘on’|‘off’)
[Command]
Enable (‘on’) or disable (‘off’) protection of flash sectors in flash bank num, starting
at sector first and continuing up to and including last. Providing a last sector of
‘last’ specifies "to the end of the flash bank". The num parameter is a value shown
by flash banks.
12.4 Flash Driver List
As noted above, the flash bank command requires a driver name, and allows driver-specific
options and behaviors. Some drivers also activate driver-specific commands.
12.4.1 External Flash
cfi
[Flash Driver]
The “Common Flash Interface” (CFI) is the main standard for external NOR flash
chips, each of which connects to a specific external chip select on the CPU. Frequently
the first such chip is used to boot the system. Your board’s reset-init handler
might need to configure additional chip selects using other commands (like: mww to
configure a bus and its timings), or perhaps configure a GPIO pin that controls the
“write protect” pin on the flash chip. The CFI driver can use a target-specific working
area to significantly speed up operation.
The CFI driver can accept the following optional parameters, in any order:
• jedec probe ... is used to detect certain non-CFI flash ROMs, like AM29LV010
and similar types.
• x16 as x8 ... when a 16-bit flash is hooked up to an 8-bit bus.
To configure two adjacent banks of 16 MBytes each, both sixteen bits (two bytes)
wide on a sixteen bit bus:
flash bank $_FLASHNAME cfi 0x00000000 0x01000000 2 2 $_TARGETNAME
flash bank $_FLASHNAME cfi 0x01000000 0x01000000 2 2 $_TARGETNAME
To configure one bank of 32 MBytes built from two sixteen bit (two byte) wide parts
wired in parallel to create a thirty-two bit (four byte) bus with doubled throughput:
flash bank $_FLASHNAME cfi 0x00000000 0x02000000 2 4 $_TARGETNAME
[Flash Driver]
Some devices form STMicroelectronics (e.g. STR75x MCU family, SPEAr MPU
family) include a proprietary “Serial Memory Interface” (SMI) controller able to drive
stmsmi
Chapter 12: Flash Commands
72
external SPI flash devices. Depending on specific device and board configuration, up
to 4 external flash devices can be connected.
SMI makes the flash content directly accessible in the CPU address space; each external device is mapped in a memory bank. CPU can directly read data, execute code
and boot from SMI banks. Normal OpenOCD commands like mdw can be used to
display the flash content.
The setup command only requires the base parameter in order to identify the memory
bank. All other parameters are ignored. Additional information, like flash size, are
detected automatically.
flash bank $_FLASHNAME stmsmi 0xf8000000 0 0 0 $_TARGETNAME
12.4.2 Internal Flash (Microcontrollers)
[Flash Driver]
The ADUC702x analog microcontrollers from Analog Devices include internal flash
and use ARM7TDMI cores. The aduc702x flash driver works with models ADUC7019
through ADUC7028. The setup command only requires the target argument since all
devices in this family have the same memory layout.
flash bank $_FLASHNAME aduc702x 0 0 0 0 $_TARGETNAME
aduc702x
[Flash Driver]
All members of the AT91SAM3 microcontroller family from Atmel include internal
flash and use ARM’s Cortex-M3 core. The driver currently (6/22/09) recognizes the
AT91SAM3U[1/2/4][C/E] chips. Note that the driver was orginaly developed and
tested using the AT91SAM3U4E, using a SAM3U-EK eval board. Support for other
chips in the family was cribbed from the data sheet. Note to future readers/updaters:
Please remove this worrysome comment after other chips are confirmed.
The AT91SAM3U4[E/C] (256K) chips have two flash banks; most other chips have
one flash bank. In all cases the flash banks are at the following fixed locations:
# Flash bank 0 - all chips
flash bank $_FLASHNAME at91sam3 0x00080000 0 1 1 $_TARGETNAME
# Flash bank 1 - only 256K chips
flash bank $_FLASHNAME at91sam3 0x00100000 0 1 1 $_TARGETNAME
Internally, the AT91SAM3 flash memory is organized as follows. Unlike the
AT91SAM7 chips, these are not used as parameters to the flash bank command:
• N-Banks: 256K chips have 2 banks, others have 1 bank.
• Bank Size: 128K/64K Per flash bank
• Sectors: 16 or 8 per bank
• SectorSize: 8K Per Sector
• PageSize: 256 bytes per page. Note that OpenOCD operates on ’sector’ sizes,
not page sizes.
at91sam3
The AT91SAM3 driver adds some additional commands:
at91sam3 gpnvm
at91sam3 gpnvm clear number
[Command]
[Command]
Chapter 12: Flash Commands
73
at91sam3 gpnvm set number
at91sam3 gpnvm show [‘all’|number]
[Command]
[Command]
With no parameters, show or show all, shows the status of all GPNVM bits.
With show number, displays that bit.
With set number or clear number, modifies that GPNVM bit.
[Command]
This command attempts to display information about the AT91SAM3 chip.
First it read the CHIPID_CIDR [address 0x400e0740, see Section 28.2.1, page
505 of the AT91SAM3U 29/may/2009 datasheet, document id: doc6430A] and
decodes the values. Second it reads the various clock configuration registers
and attempts to display how it believes the chip is configured. By default, the
SLOWCLK is assumed to be 32768 Hz, see the command at91sam3 slowclk.
at91sam3 info
at91sam3 slowclk [value]
[Command]
This command shows/sets the slow clock frequency used in the at91sam3 info
command calculations above.
[Flash Driver]
All members of the AT91SAM4 microcontroller family from Atmel include internal
flash and use ARM’s Cortex-M4 core. This driver uses the same cmd names/syntax
as See [at91sam3], page 72.
at91sam4
[Flash Driver]
All members of the AT91SAM7 microcontroller family from Atmel include internal
flash and use ARM7TDMI cores. The driver automatically recognizes a number of
these chips using the chip identification register, and autoconfigures itself.
flash bank $_FLASHNAME at91sam7 0 0 0 0 $_TARGETNAME
For chips which are not recognized by the controller driver, you must provide additional parameters in the following order:
• chip model ... label used with flash info
• banks
• sectors per bank
• pages per sector
• pages size
• num nvm bits
• freq khz ... required if an external clock is provided, optional (but recommended)
when the oscillator frequency is known
at91sam7
It is recommended that you provide zeroes for all of those values except the clock
frequency, so that everything except that frequency will be autoconfigured. Knowing
the frequency helps ensure correct timings for flash access.
The flash controller handles erases automatically on a page (128/256 byte) basis, so
explicit erase commands are not necessary for flash programming. However, there is
an “EraseAll“ command that can erase an entire flash plane (of up to 256KB), and
it will be used automatically when you issue flash erase_sector or flash erase_
address commands.
Chapter 12: Flash Commands
74
at91sam7 gpnvm bitnum (‘set’|‘clear’)
[Command]
Set or clear a “General Purpose Non-Volatile Memory” (GPNVM) bit for the
processor. Each processor has a number of such bits, used for controlling features such as brownout detection (so they are not truly general purpose).
Note: This assumes that the first flash bank (number 0) is associated with the appropriate at91sam7 target.
avr
[Flash Driver]
The AVR 8-bit microcontrollers from Atmel integrate flash memory. The current
implementation is incomplete.
[Flash Driver]
Most members of the LPC1700 and LPC2000 microcontroller families from NXP include internal flash and use Cortex-M3 (LPC1700) or ARM7TDMI (LPC2000) cores.
lpc2000
Note: There are LPC2000 devices which are not supported by the lpc2000
driver: The LPC2888 is supported by the lpc288x driver. The LPC29xx
family is supported by the lpc2900 driver.
The lpc2000 driver defines two mandatory and one optional parameters, which must
appear in the following order:
• variant ... required, may be ‘lpc2000_v1’ (older LPC21xx and LPC22xx)
‘lpc2000_v2’ (LPC213x, LPC214x, LPC210[123], LPC23xx and LPC24xx) or
‘lpc1700’ (LPC175x and LPC176x)
• clock kHz ... the frequency, in kiloHertz, at which the core is running
• ‘calc_checksum’ ... optional (but you probably want to provide this!), telling
the driver to calculate a valid checksum for the exception vector table.
Note: If you don’t provide ‘calc_checksum’ when you’re writing the
vector table, the boot ROM will almost certainly ignore your flash
image. However, if you do provide it, with most tool chains verify_
image will fail.
LPC flashes don’t require the chip and bus width to be specified.
flash bank $_FLASHNAME lpc2000 0x0 0x7d000 0 0 $_TARGETNAME \
lpc2000_v2 14765 calc_checksum
lpc2000 part_id bank
[Command]
Displays the four byte part identifier associated with the specified flash bank.
[Flash Driver]
The LPC2888 microcontroller from NXP needs slightly different flash support from
its lpc2000 siblings. The lpc288x driver defines one mandatory parameter, the programming clock rate in Hz. LPC flashes don’t require the chip and bus width to be
specified.
lpc288x
flash bank $_FLASHNAME lpc288x 0 0 0 0 $_TARGETNAME 12000000
[Flash Driver]
This driver supports the LPC29xx ARM968E based microcontroller family from NXP.
lpc2900
Chapter 12: Flash Commands
75
The predefined parameters base, size, chip width and bus width of the flash bank
command are ignored. Flash size and sector layout are auto-configured by the driver.
The driver has one additional mandatory parameter: The CPU clock rate (in kHz)
at the time the flash operations will take place. Most of the time this will not be the
crystal frequency, but a higher PLL frequency. The reset-init event handler in the
board script is usually the place where you start the PLL.
The driver rejects flashless devices (currently the LPC2930).
The EEPROM in LPC2900 devices is not mapped directly into the address space. It
must be handled much more like NAND flash memory, and will therefore be handled
by a separate lpc2900_eeprom driver (not yet available).
Sector protection in terms of the LPC2900 is handled transparently. Every time a
sector needs to be erased or programmed, it is automatically unprotected. What is
shown as protection status in the flash info command, is actually the LPC2900
sector security. This is a mechanism to prevent a sector from ever being erased or
programmed again. As this is an irreversible mechanism, it is handled by a special command (lpc2900 secure_sector), and not by the standard flash protect
command.
Example for a 125 MHz clock frequency:
flash bank $_FLASHNAME lpc2900 0 0 0 0 $_TARGETNAME 125000
Some lpc2900-specific commands are defined. In the following command list, the
bank parameter is the bank number as obtained by the flash banks command.
lpc2900 signature bank
[Command]
Calculates a 128-bit hash value, the signature, from the whole flash content.
This is a hardware feature of the flash block, hence the calculation is very fast.
You may use this to verify the content of a programmed device against a known
signature. Example:
lpc2900 signature 0
signature: 0x5f40cdc8:0xc64e592e:0x10490f89:0x32a0f317
lpc2900 read_custom bank filename
[Command]
Reads the 912 bytes of customer information from the flash index sector, and
saves it to a file in binary format. Example:
lpc2900 read_custom 0 /path_to/customer_info.bin
The index sector of the flash is a write-only sector. It cannot be erased! In order to
guard against unintentional write access, all following commands need to be preceeded
by a successful call to the password command:
lpc2900 password bank password
[Command]
You need to use this command right before each of the following commands:
lpc2900 write_custom, lpc2900 secure_sector, lpc2900 secure_jtag.
The password string is fixed to "I know what I am doing". Example:
lpc2900 password 0 I_know_what_I_am_doing
Potentially dangerous operation allowed in next command!
Chapter 12: Flash Commands
76
lpc2900 write_custom bank filename type
[Command]
Writes the content of the file into the customer info space of the flash index
sector. The filetype can be specified with the type field. Possible values for type
are: bin (binary), ihex (Intel hex format), elf (ELF binary) or s19 (Motorola
S-records). The file must contain a single section, and the contained data length
must be exactly 912 bytes.
Attention: This cannot be reverted! Be careful!
Example:
lpc2900 write_custom 0 /path_to/customer_info.bin bin
lpc2900 secure_sector bank first last
[Command]
Secures the sector range from first to last (including) against further program
and erase operations. The sector security will be effective after the next power
cycle.
Attention: This cannot be reverted! Be careful!
Secured sectors appear as protected in the flash info command. Example:
lpc2900 secure_sector 0 1 1
flash info 0
#0 : lpc2900 at 0x20000000, size 0x000c0000, (...)
# 0: 0x00000000 (0x2000 8kB) not protected
# 1: 0x00002000 (0x2000 8kB) protected
# 2: 0x00004000 (0x2000 8kB) not protected
lpc2900 secure_jtag bank
[Command]
Irreversibly disable the JTAG port. The new JTAG security setting will be
effective after the next power cycle.
Attention: This cannot be reverted! Be careful!
Examples:
lpc2900 secure_jtag 0
[Flash Driver]
ocl
No idea what this is, other than using some arm7/arm9 core.
flash bank $_FLASHNAME ocl 0 0 0 0 $_TARGETNAME
[Flash Driver]
The PIC32MX microcontrollers are based on the MIPS 4K cores, and integrate flash
memory.
flash bank $_FLASHNAME pix32mx 0x1fc00000 0 0 0 $_TARGETNAME
flash bank $_FLASHNAME pix32mx 0x1d000000 0 0 0 $_TARGETNAME
Some pic32mx-specific commands are defined:
pic32mx
pic32mx pgm_word address value bank
[Command]
Programs the specified 32-bit value at the given address in the specified chip
bank.
pic32mx unlock bank
[Command]
Unlock and erase specified chip bank. This will remove any Code Protection.
Chapter 12: Flash Commands
77
[Flash Driver]
All members of the Stellaris LM3Sxxx microcontroller family from Texas Instruments
include internal flash and use ARM Cortex M3 cores. The driver automatically recognizes a number of these chips using the chip identification register, and autoconfigures
itself.1
flash bank $_FLASHNAME stellaris 0 0 0 0 $_TARGETNAME
stellaris
[Command]
Performs the Recovering a "Locked" Device procedure to restore the flash specified
by bank id and its associated nonvolatile registers to their factory default values
(erased). This is the only way to remove flash protection or re-enable debugging if
that capability has been disabled.
Note that the final "power cycle the chip" step in this procedure must be performed
by hand, since OpenOCD can’t do it.
Warning: if more than one Stellaris chip is connected, the procedure is
applied to all of them.
stellaris recover bank_id
[Flash Driver]
All members of the STM32f1x microcontroller family from ST Microelectronics include internal flash and use ARM Cortex M3 cores. The driver automatically recognizes a number of these chips using the chip identification register, and autoconfigures
itself.
flash bank $_FLASHNAME stm32f1x 0 0 0 0 $_TARGETNAME
If you have a target with dual flash banks then define the second bank as per the
following example.
flash bank $_FLASHNAME stm32f1x 0x08080000 0 0 0 $_TARGETNAME
Some stm32f1x-specific commands2 are defined:
stm32f1x
stm32f1x lock num
[Command]
Locks the entire stm32 device. The num parameter is a value shown by flash
banks.
stm32f1x unlock num
[Command]
Unlocks the entire stm32 device. The num parameter is a value shown by flash
banks.
stm32f1x options_read num
[Command]
Read and display the stm32 option bytes written by the stm32f1x options_
write command. The num parameter is a value shown by flash banks.
stm32f1x options_write num (‘SWWDG’|‘HWWDG’)
(‘RSTSTNDBY’|‘NORSTSTNDBY’) (‘RSTSTOP’|‘NORSTSTOP’)
[Command]
Writes the stm32 option byte with the specified values. The num parameter is
a value shown by flash banks.
1
2
Currently there is a stellaris mass_erase command. That seems pointless since the same effect can be
had using the standard flash erase_address command.
Currently there is a stm32f1x mass_erase command. That seems pointless since the same effect can be had
using the standard flash erase_address command.
Chapter 12: Flash Commands
78
[Flash Driver]
All members of the STM32f2x microcontroller family from ST Microelectronics include internal flash and use ARM Cortex M3 cores. The driver automatically recognizes a number of these chips using the chip identification register, and autoconfigures
itself.
stm32f2x
[Flash Driver]
All members of the STR7 microcontroller family from ST Microelectronics include
internal flash and use ARM7TDMI cores. The str7x driver defines one mandatory
parameter, variant, which is either STR71x, STR73x or STR75x.
flash bank $_FLASHNAME str7x 0x40000000 0x00040000 0 0 $_TARGETNAME STR71x
str7x
str7x disable_jtag bank
[Command]
Activate the Debug/Readout protection mechanism for the specified flash bank.
[Flash Driver]
Most members of the STR9 microcontroller family from ST Microelectronics include
internal flash and use ARM966E cores. The str9 needs the flash controller to be
configured using the str9x flash_config command prior to Flash programming.
flash bank $_FLASHNAME str9x 0x40000000 0x00040000 0 0 $_TARGETNAME
str9x flash_config 0 4 2 0 0x80000
str9x
str9x flash_config num bbsr nbbsr bbadr nbbadr
[Command]
Configures the str9 flash controller. The num parameter is a value shown by
flash banks.
• bbsr - Boot Bank Size register
• nbbsr - Non Boot Bank Size register
• bbadr - Boot Bank Start Address register
• nbbadr - Boot Bank Start Address register
[Flash Driver]
Most members of the TMS470 microcontroller family from Texas Instruments include
internal flash and use ARM7TDMI cores. This driver doesn’t require the chip and
bus width to be specified.
Some tms470-specific commands are defined:
tms470
tms470 flash_keyset key0 key1 key2 key3
[Command]
Saves programming keys in a register, to enable flash erase and write commands.
tms470 osc_mhz clock mhz
[Command]
Reports the clock speed, which is used to calculate timings.
tms470 plldis (0|1)
[Command]
Disables (1) or enables (0) use of the PLL to speed up the flash clock.
[Flash Driver]
This is a special driver that maps a previously defined bank to another address. All
bank settings will be copied from the master physical bank.
The virtual driver defines one mandatory parameters,
virtual
Chapter 12: Flash Commands
79
• master bank The bank that this virtual address refers to.
So in the following example addresses 0xbfc00000 and 0x9fc00000 refer to the flash
bank defined at address 0x1fc00000. Any cmds executed on the virtual banks are
actually performed on the physical banks.
flash bank $_FLASHNAME pic32mx 0x1fc00000 0 0 0 $_TARGETNAME
flash bank vbank0 virtual 0xbfc00000 0 0 0 $_TARGETNAME $_FLASHNAME
flash bank vbank1 virtual 0x9fc00000 0 0 0 $_TARGETNAME $_FLASHNAME
fm3
[Flash Driver]
All members of the FM3 microcontroller family from Fujitsu include internal flash
and use ARM Cortex M3 cores. The fm3 driver uses the target parameter to select
the correct bank config, it can currently be one of the following: mb9bfxx1.cpu,
mb9bfxx2.cpu, mb9bfxx3.cpu, mb9bfxx4.cpu, mb9bfxx5.cpu or mb9bfxx6.cpu.
flash bank $_FLASHNAME fm3 0 0 0 0 $_TARGETNAME
12.4.3 str9xpec driver
Here is some background info to help you better understand how this driver works.
OpenOCD has two flash drivers for the str9:
1. Standard driver ‘str9x’ programmed via the str9 core. Normally used for flash programming as it is faster than the ‘str9xpec’ driver.
2. Direct programming ‘str9xpec’ using the flash controller. This is an ISC compilant
(IEEE 1532) tap connected in series with the str9 core. The str9 core does not need
to be running to program using this flash driver. Typical use for this driver is locking/unlocking the target and programming the option bytes.
Before we run any commands using the ‘str9xpec’ driver we must first disable the str9
core. This example assumes the ‘str9xpec’ driver has been configured for flash bank 0.
# assert srst, we do not want core running
# while accessing str9xpec flash driver
jtag_reset 0 1
# turn off target polling
poll off
# disable str9 core
str9xpec enable_turbo 0
# read option bytes
str9xpec options_read 0
# re-enable str9 core
str9xpec disable_turbo 0
poll on
reset halt
The above example will read the str9 option bytes. When performing a unlock remember
that you will not be able to halt the str9 - it has been locked. Halting the core is not required
for the ‘str9xpec’ driver as mentioned above, just issue the commands above manually or
from a telnet prompt.
Chapter 12: Flash Commands
80
[Flash Driver]
Only use this driver for locking/unlocking the device or configuring the option bytes.
Use the standard str9 driver for programming. Before using the flash commands the
turbo mode must be enabled using the str9xpec enable_turbo command.
Several str9xpec-specific commands are defined:
str9xpec
str9xpec disable_turbo num
[Command]
Restore the str9 into JTAG chain.
str9xpec enable_turbo num
[Command]
Enable turbo mode, will simply remove the str9 from the chain and talk directly
to the embedded flash controller.
str9xpec lock num
[Command]
Lock str9 device. The str9 will only respond to an unlock command that will
erase the device.
str9xpec part_id num
[Command]
Prints the part identifier for bank num.
str9xpec options_cmap num (‘bank0’|‘bank1’)
[Command]
Configure str9 boot bank.
str9xpec options_lvdsel num (‘vdd’|‘vdd_vddq’)
[Command]
Configure str9 lvd source.
str9xpec options_lvdthd num (‘2.4v’|‘2.7v’)
[Command]
Configure str9 lvd threshold.
str9xpec options_lvdwarn bank (‘vdd’|‘vdd_vddq’)
[Command]
Configure str9 lvd reset warning source.
str9xpec options_read num
[Command]
Read str9 option bytes.
str9xpec options_write num
[Command]
Write str9 option bytes.
str9xpec unlock num
[Command]
unlock str9 device.
12.5 mFlash
12.5.1 mFlash Configuration
mflash bank soc base RST pin target
[Config Command]
Configures a mflash for soc host bank at address base. The pin number format
depends on the host GPIO naming convention. Currently, the mflash driver supports
s3c2440 and pxa270.
Example for s3c2440 mflash where RST pin is GPIO B1:
Chapter 12: Flash Commands
81
mflash bank $_FLASHNAME s3c2440 0x10000000 1b 0
Example for pxa270 mflash where RST pin is GPIO 43:
mflash bank $_FLASHNAME pxa270 0x08000000 43 0
12.5.2 mFlash commands
mflash config pll frequency
[Command]
Configure mflash PLL. The frequency is the mflash input frequency, in Hz. Issuing this command will erase mflash’s whole internal nand and write new pll. After
this command, mflash needs power-on-reset for normal operation. If pll was newly
configured, storage and boot(optional) info also need to be update.
[Command]
Configure bootable option. If bootable option is set, mflash offer the first 8 sectors
(4kB) for boot.
mflash config boot
[Command]
Configure storage information. For the normal storage operation, this information
must be written.
mflash config storage
mflash dump num filename offset size
[Command]
Dump size bytes, starting at offset bytes from the beginning of the bank num, to the
file named filename.
mflash probe
[Command]
Probe mflash.
mflash write num filename offset
[Command]
Write the binary file filename to mflash bank num, starting at offset bytes from the
beginning of the bank.
Chapter 13: NAND Flash Commands
82
13 NAND Flash Commands
Compared to NOR or SPI flash, NAND devices are inexpensive and high density. Today’s
NAND chips, and multi-chip modules, commonly hold multiple GigaBytes of data.
NAND chips consist of a number of “erase blocks” of a given size (such as 128 KBytes),
each of which is divided into a number of pages (of perhaps 512 or 2048 bytes each). Each
page of a NAND flash has an “out of band” (OOB) area to hold Error Correcting Code
(ECC) and other metadata, usually 16 bytes of OOB for every 512 bytes of page data.
One key characteristic of NAND flash is that its error rate is higher than that of NOR
flash. In normal operation, that ECC is used to correct and detect errors. However, NAND
blocks can also wear out and become unusable; those blocks are then marked "bad". NAND
chips are even shipped from the manufacturer with a few bad blocks. The highest density
chips use a technology (MLC) that wears out more quickly, so ECC support is increasingly
important as a way to detect blocks that have begun to fail, and help to preserve data
integrity with techniques such as wear leveling.
Software is used to manage the ECC. Some controllers don’t support ECC directly; in
those cases, software ECC is used. Other controllers speed up the ECC calculations with
hardware. Single-bit error correction hardware is routine. Controllers geared for newer
MLC chips may correct 4 or more errors for every 512 bytes of data.
You will need to make sure that any data you write using OpenOCD includes the apppropriate kind of ECC. For example, that may mean passing the oob_softecc flag when
writing NAND data, or ensuring that the correct hardware ECC mode is used.
The basic steps for using NAND devices include:
1. Declare via the command nand device
Do this in a board-specific configuration file, passing parameters as needed by the
controller.
2. Configure each device using nand probe.
Do this only after the associated target is set up, such as in its reset-init script or in
procures defined to access that device.
3. Operate on the flash via nand subcommand
Often commands to manipulate the flash are typed by a human, or run via a script in
some automated way. Common task include writing a boot loader, operating system,
or other data needed to initialize or de-brick a board.
NOTE: At the time this text was written, the largest NAND flash fully supported by
OpenOCD is 2 GiBytes (16 GiBits). This is because the variables used to hold offsets and
lengths are only 32 bits wide. (Larger chips may work in some cases, unless an offset or
length is larger than 0xffffffff, the largest 32-bit unsigned integer.) Some larger devices
will work, since they are actually multi-chip modules with two smaller chips and individual
chipselect lines.
13.1 NAND Configuration Commands
NAND chips must be declared in configuration scripts, plus some additional configuration
that’s done after OpenOCD has initialized.
Chapter 13: NAND Flash Commands
83
nand device name driver target [configparams...]
[Config Command]
Declares a NAND device, which can be read and written to after it has been configured
through nand probe. In OpenOCD, devices are single chips; this is unlike some
operating systems, which may manage multiple chips as if they were a single (larger)
device. In some cases, configuring a device will activate extra commands; see the
controller-specific documentation.
NOTE: This command is not available after OpenOCD initialization has completed.
Use it in board specific configuration files, not interactively.
• name ... may be used to reference the NAND bank in most other NAND commands. A number is also available.
• driver ... identifies the NAND controller driver associated with the NAND device
being declared. See [NAND Driver List], page 86.
• target ... names the target used when issuing commands to the NAND controller.
• configparams ... controllers may support, or require, additional parameters. See
the controller-specific documentation for more information.
[Command]
Prints a summary of each device declared using nand device, numbered from zero.
Note that un-probed devices show no details.
> nand list
#0: NAND 1GiB 3,3V 8-bit (Micron) pagesize: 2048, buswidth: 8,
blocksize: 131072, blocks: 8192
#1: NAND 1GiB 3,3V 8-bit (Micron) pagesize: 2048, buswidth: 8,
blocksize: 131072, blocks: 8192
>
nand list
nand probe num
[Command]
Probes the specified device to determine key characteristics like its page and block
sizes, and how many blocks it has. The num parameter is the value shown by nand
list. You must (successfully) probe a device before you can use it with most other
NAND commands.
13.2 Erasing, Reading, Writing to NAND Flash
nand dump num filename offset length [oob option]
[Command]
Reads binary data from the NAND device and writes it to the file, starting at the
specified offset. The num parameter is the value shown by nand list.
Use a complete path name for filename, so you don’t depend on the directory used to
start the OpenOCD server.
The offset and length must be exact multiples of the device’s page size. They describe
a data region; the OOB data associated with each such page may also be accessed.
NOTE: At the time this text was written, no error correction was done on the data
that’s read, unless raw access was disabled and the underlying NAND controller driver
had a read_page method which handled that error correction.
By default, only page data is saved to the specified file. Use an oob option parameter
to save OOB data:
Chapter 13: NAND Flash Commands
84
• no oob * parameter
Output file holds only page data; OOB is discarded.
• oob_raw
Output file interleaves page data and OOB data; the file will be longer than
"length" by the size of the spare areas associated with each data page. Note that
this kind of "raw" access is different from what’s implied by nand raw_access,
which just controls whether a hardware-aware access method is used.
• oob_only
Output file has only raw OOB data, and will be smaller than "length" since it
will contain only the spare areas associated with each data page.
nand erase num [offset length]
[Command]
Erases blocks on the specified NAND device, starting at the specified offset and continuing for length bytes. Both of those values must be exact multiples of the device’s
block size, and the region they specify must fit entirely in the chip. If those parameters are not specified, the whole NAND chip will be erased. The num parameter is
the value shown by nand list.
NOTE: This command will try to erase bad blocks, when told to do so, which will
probably invalidate the manufacturer’s bad block marker. For the remainder of the
current server session, nand info will still report that the block “is” bad.
nand write num filename offset [option...]
[Command]
Writes binary data from the file into the specified NAND device, starting at the
specified offset. Those pages should already have been erased; you can’t change zero
bits to one bits. The num parameter is the value shown by nand list.
Use a complete path name for filename, so you don’t depend on the directory used to
start the OpenOCD server.
The offset must be an exact multiple of the device’s page size. All data in the file
will be written, assuming it doesn’t run past the end of the device. Only full pages
are written, and any extra space in the last page will be filled with 0xff bytes. (That
includes OOB data, if that’s being written.)
NOTE: At the time this text was written, bad blocks are ignored. That is, this routine
will not skip bad blocks, but will instead try to write them. This can cause problems.
Provide at most one option parameter. With some NAND drivers, the meanings of
these parameters may change if nand raw_access was used to disable hardware ECC.
• no oob * parameter
File has only page data, which is written. If raw acccess is in use, the OOB area
will not be written. Otherwise, if the underlying NAND controller driver has a
write_page routine, that routine may write the OOB with hardware-computed
ECC data.
• oob_only
File has only raw OOB data, which is written to the OOB area. Each page’s data
area stays untouched. This can be a dangerous option, since it can invalidate the
ECC data. You may need to force raw access to use this mode.
• oob_raw
File interleaves data and OOB data, both of which are written If raw access is
Chapter 13: NAND Flash Commands
85
enabled, the data is written first, then the un-altered OOB. Otherwise, if the
underlying NAND controller driver has a write_page routine, that routine may
modify the OOB before it’s written, to include hardware-computed ECC data.
• oob_softecc
File has only page data, which is written. The OOB area is filled with 0xff,
except for a standard 1-bit software ECC code stored in conventional locations.
You might need to force raw access to use this mode, to prevent the underlying
driver from applying hardware ECC.
• oob_softecc_kw
File has only page data, which is written. The OOB area is filled with 0xff, except
for a 4-bit software ECC specific to the boot ROM in Marvell Kirkwood SoCs.
You might need to force raw access to use this mode, to prevent the underlying
driver from applying hardware ECC.
nand verify num filename offset [option...]
[Command]
Verify the binary data in the file has been programmed to the specified NAND device,
starting at the specified offset. The num parameter is the value shown by nand list.
Use a complete path name for filename, so you don’t depend on the directory used to
start the OpenOCD server.
The offset must be an exact multiple of the device’s page size. All data in the file
will be read and compared to the contents of the flash, assuming it doesn’t run past
the end of the device. As with nand write, only full pages are verified, so any extra
space in the last page will be filled with 0xff bytes.
The same options accepted by nand write, and the file will be processed similarly to
produce the buffers that can be compared against the contents produced from nand
dump.
NOTE: This will not work when the underlying NAND controller driver’s write_
page routine must update the OOB with a hardward-computed ECC before the data
is written. This limitation may be removed in a future release.
13.3 Other NAND commands
nand check_bad_blocks num [offset length]
[Command]
Checks for manufacturer bad block markers on the specified NAND device. If no
parameters are provided, checks the whole device; otherwise, starts at the specified
offset and continues for length bytes. Both of those values must be exact multiples of
the device’s block size, and the region they specify must fit entirely in the chip. The
num parameter is the value shown by nand list.
NOTE: Before using this command you should force raw access with nand raw_access
enable to ensure that the underlying driver will not try to apply hardware ECC.
nand info num
[Command]
The num parameter is the value shown by nand list. This prints the one-line summary from "nand list", plus for devices which have been probed this also prints any
known status for each block.
Chapter 13: NAND Flash Commands
86
nand raw_access num (‘enable’|‘disable’)
[Command]
Sets or clears an flag affecting how page I/O is done. The num parameter is the value
shown by nand list.
This flag is cleared (disabled) by default, but changing that value won’t affect all
NAND devices. The key factor is whether the underlying driver provides read_page
or write_page methods. If it doesn’t provide those methods, the setting of this flag
is irrelevant; all access is effectively “raw”.
When those methods exist, they are normally used when reading data (nand dump or
reading bad block markers) or writing it (nand write). However, enabling raw access
(setting the flag) prevents use of those methods, bypassing hardware ECC logic. This
can be a dangerous option, since writing blocks with the wrong ECC data can cause
them to be marked as bad.
13.4 NAND Driver List
As noted above, the nand device command allows driver-specific options and behaviors.
Some controllers also activate controller-specific commands.
[NAND Driver]
This driver handles the NAND controllers found on AT91SAM9 family chips from
Atmel. It takes two extra parameters: address of the NAND chip; address of the
ECC controller.
nand device $NANDFLASH at91sam9 $CHIPNAME 0x40000000 0xfffffe800
AT91SAM9 chips support single-bit ECC hardware. The write_page and read_page
methods are used to utilize the ECC hardware unless they are disabled by using the
nand raw_access command. There are four additional commands that are needed to
fully configure the AT91SAM9 NAND controller. Two are optional; most boards use
the same wiring for ALE/CLE:
at91sam9
at91sam9 cle num addr line
[Command]
Configure the address line used for latching commands. The num parameter is
the value shown by nand list.
at91sam9 ale num addr line
[Command]
Configure the address line used for latching addresses. The num parameter is
the value shown by nand list.
For the next two commands, it is assumed that the pins have already been properly
configured for input or output.
at91sam9 rdy_busy num pio base addr pin
[Command]
Configure the RDY/nBUSY input from the NAND device. The num parameter
is the value shown by nand list. pio base addr is the base address of the PIO
controller and pin is the pin number.
at91sam9 ce num pio base addr pin
[Command]
Configure the chip enable input to the NAND device. The num parameter is
the value shown by nand list. pio base addr is the base address of the PIO
controller and pin is the pin number.
Chapter 13: NAND Flash Commands
87
[NAND Driver]
This driver handles the NAND controllers found on DaVinci family chips from Texas
Instruments. It takes three extra parameters: address of the NAND chip; hardware
ECC mode to use (‘hwecc1’, ‘hwecc4’, ‘hwecc4_infix’); address of the AEMIF controller on this processor.
davinci
nand device davinci dm355.arm 0x02000000 hwecc4 0x01e10000
All DaVinci processors support the single-bit ECC hardware, and newer ones also
support the four-bit ECC hardware. The write_page and read_page methods are
used to implement those ECC modes, unless they are disabled using the nand raw_
access command.
[NAND Driver]
These controllers require an extra nand device parameter: the clock rate used by the
controller.
lpc3180
lpc3180 select num [mlc|slc]
[Command]
Configures use of the MLC or SLC controller mode. MLC implies use of hardware ECC. The num parameter is the value shown by nand list.
At this writing, this driver includes write_page and read_page methods. Using nand
raw_access to disable those methods will prevent use of hardware ECC in the MLC
controller mode, but won’t change SLC behavior.
mx3
[NAND Driver]
This driver handles the NAND controller in i.MX31. The mxc driver should work for
this chip aswell.
mxc
[NAND Driver]
This driver handles the NAND controller found in Freescale i.MX chips. It has support
for v1 (i.MX27 and i.MX31) and v2 (i.MX35). The driver takes 3 extra arguments,
chip (‘mx27’, ‘mx31’, ‘mx35’), ecc (‘noecc’, ‘hwecc’) and optionally if bad block information should be swapped between main area and spare area (‘biswap’), defaults to
off.
nand device mx35.nand mxc imx35.cpu mx35 hwecc biswap
mxc biswap bank num [enable|disable]
[Command]
Turns on/off bad block information swaping from main area, without parameter
query status.
[NAND Driver]
These controllers require an extra nand device parameter: the address of the controller.
orion
nand device orion 0xd8000000
These controllers don’t define any specialized commands. At this writing, their drivers
don’t include write_page or read_page methods, so nand raw_access won’t change
any behavior.
Chapter 13: NAND Flash Commands
88
[NAND Driver]
[NAND Driver]
[NAND Driver]
[NAND Driver]
[NAND Driver]
These S3C family controllers don’t have any special nand device options, and don’t
define any specialized commands. At this writing, their drivers don’t include write_
page or read_page methods, so nand raw_access won’t change any behavior.
s3c2410
s3c2412
s3c2440
s3c2443
s3c6400
Chapter 14: PLD/FPGA Commands
89
14 PLD/FPGA Commands
Programmable Logic Devices (PLDs) and the more flexible Field Programmable Gate Arrays (FPGAs) are both types of programmable hardware. OpenOCD can support programming them. Although PLDs are generally restrictive (cells are less functional, and there are
no special purpose cells for memory or computational tasks), they share the same OpenOCD
infrastructure. Accordingly, both are called PLDs here.
14.1 PLD/FPGA Configuration and Commands
As it does for JTAG TAPs, debug targets, and flash chips (both NOR and NAND),
OpenOCD maintains a list of PLDs available for use in various commands. Also, each
such PLD requires a driver.
They are referenced by the number shown by the pld devices command, and new PLDs
are defined by pld device driver_name.
pld device driver name tap name [driver options]
[Config Command]
Defines a new PLD device, supported by driver driver name, using the TAP named
tap name. The driver may make use of any driver options to configure its behavior.
pld devices
[Command]
Lists the PLDs and their numbers.
pld load num filename
[Command]
Loads the file ‘filename’ into the PLD identified by num. The file format must be
inferred by the driver.
14.2 PLD/FPGA Drivers, Options, and Commands
Drivers may support PLD-specific options to the pld device definition command, and may
also define commands usable only with that particular type of PLD.
[FPGA Driver]
Virtex-II is a family of FPGAs sold by Xilinx. It supports the IEEE 1532 standard for
In-System Configuration (ISC). No driver-specific PLD definition options are used,
and one driver-specific command is defined.
virtex2
virtex2 read_stat num
[Command]
Reads and displays the Virtex-II status register (STAT) for FPGA num.
Chapter 15: General Commands
90
15 General Commands
The commands documented in this chapter here are common commands that you, as a
human, may want to type and see the output of. Configuration type commands are documented elsewhere.
Intent:
• Source Of Commands
OpenOCD commands can occur in a configuration script (discussed elsewhere) or typed
manually by a human or supplied programatically, or via one of several TCP/IP Ports.
• From the human
A human should interact with the telnet interface (default port: 4444) or via GDB
(default port 3333).
To issue commands from within a GDB session, use the ‘monitor’ command, e.g. use
‘monitor poll’ to issue the ‘poll’ command. All output is relayed through the GDB
session.
• Machine Interface The Tcl interface’s intent is to be a machine interface. The default
Tcl port is 5555.
15.1 Daemon Commands
[Command]
exit
Exits the current telnet session.
help [string]
[Command]
With no parameters, prints help text for all commands. Otherwise, prints each helptext containing string. Not every command provides helptext.
Configuration commands, and commands valid at any time, are explicitly noted in
parenthesis. In most cases, no such restriction is listed; this indicates commands
which are only available after the configuration stage has completed.
sleep msec [‘busy’]
[Command]
Wait for at least msec milliseconds before resuming. If ‘busy’ is passed, busy-wait
instead of sleeping. (This option is strongly discouraged.) Useful in connection with
script files (script command and target_name configuration).
[Command]
Close the OpenOCD daemon, disconnecting all clients (GDB, telnet, other).
shutdown
debug_level [n]
[Command]
Display debug level. If n (from 0..3) is provided, then set it to that level. This affects
the kind of messages sent to the server log. Level 0 is error messages only; level 1 adds
warnings; level 2 adds informational messages; and level 3 adds debugging messages.
The default is level 2, but that can be overridden on the command line along with
the location of that log file (which is normally the server’s standard output). See
Chapter 4 [Running], page 11.
Chapter 15: General Commands
91
echo [-n] message
[Command]
Logs a message at "user" priority. Output message to stdout. Option "-n" suppresses
trailing newline.
echo "Downloading kernel -- please wait"
log_output [filename]
[Command]
Redirect logging to filename; the initial log output channel is stderr.
add_script_search_dir [directory]
[Command]
Add directory to the file/script search path.
15.2 Target State handling
In this section “target” refers to a CPU configured as shown earlier (see Chapter 11 [CPU
Configuration], page 59). These commands, like many, implicitly refer to a current target
which is used to perform the various operations. The current target may be changed by
using targets command with the name of the target which should become current.
reg [(number|name) [value]]
[Command]
Access a single register by number or by its name. The target must generally be
halted before access to CPU core registers is allowed. Depending on the hardware,
some other registers may be accessible while the target is running.
With no arguments: list all available registers for the current target, showing number,
name, size, value, and cache status. For valid entries, a value is shown; valid entries
which are also dirty (and will be written back later) are flagged as such.
With number/name: display that register’s value.
With both number/name and value: set register’s value. Writes may be held in a
writeback cache internal to OpenOCD, so that setting the value marks the register as
dirty instead of immediately flushing that value. Resuming CPU execution (including
by single stepping) or otherwise activating the relevant module will flush such values.
Cores may have surprisingly many registers in their Debug and trace infrastructure:
> reg
===== ARM registers
(0) r0 (/32): 0x0000D3C2 (dirty)
(1) r1 (/32): 0xFD61F31C
(2) r2 (/32)
...
(164) ETM_contextid_comparator_mask (/32)
>
halt [ms]
wait_halt [ms]
[Command]
[Command]
The halt command first sends a halt request to the target, which wait_halt doesn’t.
Otherwise these behave the same: wait up to ms milliseconds, or 5 seconds if there
is no parameter, for the target to halt (and enter debug mode). Using 0 as the ms
parameter prevents OpenOCD from waiting.
Warning: On ARM cores, software using the wait for interrupt operation
often blocks the JTAG access needed by a halt command. This is because
Chapter 15: General Commands
92
that operation also puts the core into a low power mode by gating the
core clock; but the core clock is needed to detect JTAG clock transitions.
One partial workaround uses adaptive clocking: when the core is interrupted the operation completes, then JTAG clocks are accepted at least
until the interrupt handler completes. However, this workaround is often
unusable since the processor, board, and JTAG adapter must all support
adaptive JTAG clocking. Also, it can’t work until an interrupt is issued.
A more complete workaround is to not use that operation while you work
with a JTAG debugger. Tasking environments generaly have idle loops
where the body is the wait for interrupt operation. (On older cores, it is
a coprocessor action; newer cores have a ‘wfi’ instruction.) Such loops
can just remove that operation, at the cost of higher power consumption
(because the CPU is needlessly clocked).
resume [address]
[Command]
Resume the target at its current code position, or the optional address if it is provided.
OpenOCD will wait 5 seconds for the target to resume.
step [address]
[Command]
Single-step the target at its current code position, or the optional address if it is
provided.
[Command]
[Command]
[Command]
[Command]
Perform as hard a reset as possible, using SRST if possible. All defined targets will
be reset, and target events will fire during the reset sequence.
The optional parameter specifies what should happen after the reset. If there is no
parameter, a reset run is executed. The other options will not work on all systems.
See Chapter 9 [Reset Configuration], page 48.
− run Let the target run
− halt Immediately halt the target
− init Immediately halt the target, and execute the reset-init script
reset
reset run
reset halt
reset init
[Command]
Requesting target halt and executing a soft reset. This is often used when a target
cannot be reset and halted. The target, after reset is released begins to execute code.
OpenOCD attempts to stop the CPU and then sets the program counter back to the
reset vector. Unfortunately the code that was executed may have left the hardware
in an unknown state.
soft_reset_halt
15.3 I/O Utilities
These commands are available when OpenOCD is built with ‘--enable-ioutil’. They are
mainly useful on embedded targets, notably the ZY1000. Hosts with operating systems
have complementary tools.
Note: there are several more such commands.
Chapter 15: General Commands
93
append_file filename [string]*
[Command]
Appends the string parameters to the text file ‘filename’. Each string except the
last one is followed by one space. The last string is followed by a newline.
cat filename
[Command]
Reads and displays the text file ‘filename’.
cp src filename dest filename
[Command]
Copies contents from the file ‘src_filename’ into ‘dest_filename’.
[Command]
ip
No description provided.
[Command]
ls
No description provided.
[Command]
mac
No description provided.
[Command]
Display available RAM memory on OpenOCD host. Used in OpenOCD regression
testing scripts.
meminfo
[Command]
peek
No description provided.
[Command]
poke
No description provided.
rm filename
[Command]
Unlinks the file ‘filename’.
trunc filename
[Command]
Removes all data in the file ‘filename’.
15.4 Memory access commands
These commands allow accesses of a specific size to the memory system. Often these are
used to configure the current target in some special way. For example - one may need to
write certain values to the SDRAM controller to enable SDRAM.
1. Use the targets (plural) command to change the current target.
2. In system level scripts these commands are deprecated. Please use their TARGET
object siblings to avoid making assumptions about what TAP is the current target, or
about MMU configuration.
mdw [phys] addr [count]
mdh [phys] addr [count]
mdb [phys] addr [count]
[Command]
[Command]
[Command]
Display contents of address addr, as 32-bit words (mdw), 16-bit halfwords (mdh), or
8-bit bytes (mdb). When the current target has an MMU which is present and active,
Chapter 15: General Commands
94
addr is interpreted as a virtual address. Otherwise, or if the optional phys flag is
specified, addr is interpreted as a physical address. If count is specified, displays that
many units. (If you want to manipulate the data instead of displaying it, see the
mem2array primitives.)
mww [phys] addr word
mwh [phys] addr halfword
mwb [phys] addr byte
[Command]
[Command]
[Command]
Writes the specified word (32 bits), halfword (16 bits), or byte (8-bit) value, at the
specified address addr. When the current target has an MMU which is present and
active, addr is interpreted as a virtual address. Otherwise, or if the optional phys
flag is specified, addr is interpreted as a physical address.
15.5 Image loading commands
dump_image filename address size
[Command]
Dump size bytes of target memory starting at address to the binary file named
filename.
[Command]
Loads an image stored in memory by fast_load_image to the current target. Must
be preceeded by fast load image.
fast_load
fast_load_image filename address [‘bin’|‘ihex’|‘elf’|‘s19’]
[Command]
Normally you should be using load_image or GDB load. However, for testing purposes or when I/O overhead is significant(OpenOCD running on an embedded host),
storing the image in memory and uploading the image to the target can be a way to
upload e.g. multiple debug sessions when the binary does not change. Arguments
are the same as load_image, but the image is stored in OpenOCD host memory, i.e.
does not affect target. This approach is also useful when profiling target programming
performance as I/O and target programming can easily be profiled separately.
load_image filename address [[‘bin’|‘ihex’|‘elf’|‘s19’] ‘min_addr’
‘max_length’]
[Command]
Load image from file filename to target memory offset by address from its load address.
The file format may optionally be specified (‘bin’, ‘ihex’, ‘elf’, or ‘s19’). In addition
the following arguments may be specifed: min addr - ignore data below min addr
(this is w.r.t. to the target’s load address + address) max length - maximum number
of bytes to load.
proc load_image_bin {fname foffset address length } {
# Load data from fname filename at foffset offset to
# target at address. Load at most length bytes.
load_image $fname [expr $address - $foffset] bin $address $length
}
test_image filename [address [‘bin’|‘ihex’|‘elf’]]
[Command]
Displays image section sizes and addresses as if filename were loaded into target
memory starting at address (defaults to zero). The file format may optionally be
specified (‘bin’, ‘ihex’, or ‘elf’)
Chapter 15: General Commands
95
verify_image filename address [‘bin’|‘ihex’|‘elf’]
[Command]
Verify filename against target memory starting at address. The file format may
optionally be specified (‘bin’, ‘ihex’, or ‘elf’) This will first attempt a comparison
using a CRC checksum, if this fails it will try a binary compare.
15.6 Breakpoint and Watchpoint commands
CPUs often make debug modules accessible through JTAG, with hardware support for
a handful of code breakpoints and data watchpoints. In addition, CPUs almost always
support software breakpoints.
bp [address len [‘hw’]]
[Command]
With no parameters, lists all active breakpoints. Else sets a breakpoint on code
execution starting at address for length bytes. This is a software breakpoint, unless
‘hw’ is specified in which case it will be a hardware breakpoint.
(See [arm9 vector catch], page 101, or see [xscale vector catch], page 105, for similar
mechanisms that do not consume hardware breakpoints.)
rbp address
[Command]
Remove the breakpoint at address.
rwp address
[Command]
Remove data watchpoint on address
wp [address len [(‘r’|‘w’|‘a’) [value [mask]]]]
[Command]
With no parameters, lists all active watchpoints. Else sets a data watchpoint on data
from address for length bytes. The watch point is an "access" watchpoint unless the
‘r’ or ‘w’ parameter is provided, defining it as respectively a read or write watchpoint.
If a value is provided, that value is used when determining if the watchpoint should
trigger. The value may be first be masked using mask to mark “don’t care” fields.
15.7 Misc Commands
profile seconds filename
[Command]
Profiling samples the CPU’s program counter as quickly as possible, which is useful
for non-intrusive stochastic profiling. Saves up to 10000 sampines in ‘filename’ using
“gmon.out” format.
version
[Command]
Displays a string identifying the version of this OpenOCD server.
virt2phys virtual address
[Command]
Requests the current target to map the specified virtual address to its corresponding
physical address, and displays the result.
Chapter 16: Architecture and Core Commands
96
16 Architecture and Core Commands
Most CPUs have specialized JTAG operations to support debugging. OpenOCD packages
most such operations in its standard command framework. Some of those operations don’t
fit well in that framework, so they are exposed here as architecture or implementation (core)
specific commands.
16.1 ARM Hardware Tracing
CPUs based on ARM cores may include standard tracing interfaces, based on an “Embedded
Trace Module” (ETM) which sends voluminous address and data bus trace records to a
“Trace Port”.
• Development-oriented boards will sometimes provide a high speed trace connector for
collecting that data, when the particular CPU supports such an interface. (The standard connector is a 38-pin Mictor, with both JTAG and trace port support.) Those
trace connectors are supported by higher end JTAG adapters and some logic analyzer
modules; frequently those modules can buffer several megabytes of trace data. Configuring an ETM coupled to such an external trace port belongs in the board-specific
configuration file.
• If the CPU doesn’t provide an external interface, it probably has an “Embedded Trace
Buffer” (ETB) on the chip, which is a dedicated SRAM. 4KBytes is one common ETB
size. Configuring an ETM coupled only to an ETB belongs in the CPU-specific (target)
configuration file, since it works the same on all boards.
ETM support in OpenOCD doesn’t seem to be widely used yet.
Issues: ETM support may be buggy, and at least some etm config parameters
should be detected by asking the ETM for them.
ETM trigger events could also implement a kind of complex hardware breakpoint, much more powerful than the simple watchpoint hardware exported by
EmbeddedICE modules. Such breakpoints can be triggered even when using the
dummy trace port driver.
It seems like a GDB hookup should be possible, as well as tracing only during
specific states (perhaps handling IRQ 23 or calls foo()).
There should be GUI tools to manipulate saved trace data and help analyse
it in conjunction with the source code. It’s unclear how much of a common
interface is shared with the current XScale trace support, or should be shared
with eventual Nexus-style trace module support.
At this writing (November 2009) only ARM7, ARM9, and ARM11 support for
ETM modules is available. The code should be able to work with some newer
cores; but not all of them support this original style of JTAG access.
16.1.1 ETM Configuration
ETM setup is coupled with the trace port driver configuration.
etm config target width mode clocking driver
[Config Command]
Declares the ETM associated with target, and associates it with a given trace port
driver. See [Trace Port Drivers], page 98.
Chapter 16: Architecture and Core Commands
97
Several of the parameters must reflect the trace port capabilities, which are a function of silicon capabilties (exposed later using etm info) and of what hardware is
connected to that port (such as an external pod, or ETB). The width must be either
4, 8, or 16, except with ETMv3.0 and newer modules which may also support 1, 2,
24, 32, 48, and 64 bit widths. (With those versions, etm info also shows whether the
selected port width and mode are supported.)
The mode must be ‘normal’, ‘multiplexed’, or ‘demultiplexed’. The clocking must
be ‘half’ or ‘full’.
Warning: With ETMv3.0 and newer, the bits set with the mode and
clocking parameters both control the mode. This modified mode does not
map to the values supported by previous ETM modules, so this syntax
is subject to change.
Note: You can see the ETM registers using the reg command. Not all
possible registers are present in every ETM. Most of the registers are
write-only, and are used to configure what CPU activities are traced.
[Command]
Displays information about the current target’s ETM. This includes resource counts
from the ETM_CONFIG register, as well as silicon capabilities (except on rather old
modules). from the ETM_SYS_CONFIG register.
etm info
[Command]
Displays status of the current target’s ETM and trace port driver: is the ETM idle,
or is it collecting data? Did trace data overflow? Was it triggered?
etm status
etm tracemode [type context id bits cycle accurate branch output]
[Command]
Displays what data that ETM will collect. If arguments are provided, first configures
that data. When the configuration changes, tracing is stopped and any buffered trace
data is invalidated.
• type ... describing how data accesses are traced, when they pass any ViewData
filtering that that was set up. The value is one of ‘none’ (save nothing), ‘data’
(save data), ‘address’ (save addresses), ‘all’ (save data and addresses)
• context id bits ... 0, 8, 16, or 32
• cycle accurate ... ‘enable’ or ‘disable’ cycle-accurate instruction tracing. Before ETMv3, enabling this causes much extra data to be recorded.
• branch output ... ‘enable’ or ‘disable’. Disable this unless you need to try
reconstructing the instruction trace stream without an image of the code.
etm trigger_debug (‘enable’|‘disable’)
[Command]
Displays whether ETM triggering debug entry (like a breakpoint) is enabled or
disabled, after optionally modifying that configuration. The default behaviour is
‘disable’. Any change takes effect after the next etm start.
By using script commands to configure ETM registers, you can make the processor enter debug state automatically when certain conditions, more complex than supported
by the breakpoint hardware, happen.
Chapter 16: Architecture and Core Commands
98
16.1.2 ETM Trace Operation
After setting up the ETM, you can use it to collect data. That data can be exported to
files for later analysis. It can also be parsed with OpenOCD, for basic sanity checking.
To configure what is being traced, you will need to write various trace registers using reg
ETM_* commands. For the definitions of these registers, read ARM publication IHI 0014,
“Embedded Trace Macrocell, Architecture Specification”. Be aware that most of the relevant
registers are write-only, and that ETM resources are limited. There are only a handful of
address comparators, data comparators, counters, and so on.
Examples of scenarios you might arrange to trace include:
• Code flow within a function, excluding subroutines it calls. Use address range comparators to enable tracing for instruction access within that function’s body.
• Code flow within a function, including subroutines it calls. Use the sequencer and
address comparators to activate tracing on an “entered function” state, then deactivate
it by exiting that state when the function’s exit code is invoked.
• Code flow starting at the fifth invocation of a function, combining one of the above
models with a counter.
• CPU data accesses to the registers for a particular device, using address range comparators and the ViewData logic.
• Such data accesses only during IRQ handling, combining the above model with sequencer triggers which on entry and exit to the IRQ handler.
• ... more
At this writing, September 2009, there are no Tcl utility procedures to help set up any
common tracing scenarios.
[Command]
Reads trace data into memory, if it wasn’t already present. Decodes and prints the
data that was collected.
etm analyze
etm dump filename
[Command]
Stores the captured trace data in ‘filename’.
etm image filename [base address] [type]
[Command]
Opens an image file.
etm load filename
[Command]
Loads captured trace data from ‘filename’.
etm start
[Command]
Starts trace data collection.
etm stop
Stops trace data collection.
[Command]
Chapter 16: Architecture and Core Commands
99
16.1.3 Trace Port Drivers
To use an ETM trace port it must be associated with a driver.
[Trace Port Driver]
Use the ‘dummy’ driver if you are configuring an ETM that’s not connected to anything
(on-chip ETB or off-chip trace connector). This driver lets OpenOCD talk to the ETM,
but it does not expose any trace data collection.
dummy
etm_dummy config target
[Config Command]
Associates the ETM for target with a dummy driver.
etb
[Trace Port Driver]
Use the ‘etb’ driver if you are configuring an ETM to use on-chip ETB memory.
etb config target etb tap
[Config Command]
Associates the ETM for target with the ETB at etb tap. You can see the ETB
registers using the reg command.
etb trigger_percent [percent]
[Command]
This displays, or optionally changes, ETB behavior after the ETM’s configured
trigger event fires. It controls how much more trace data is saved after the
(single) trace trigger becomes active.
• The default corresponds to trace around usage, recording 50 percent data
before the event and the rest afterwards.
• The minimum value of percent is 2 percent, recording almost exclusively
data before the trigger. Such extreme trace before usage can help figure
out what caused that event to happen.
• The maximum value of percent is 100 percent, recording data almost exclusively after the event. This extreme trace after usage might help sort
out how the event caused trouble.
[Trace Port Driver]
This driver isn’t available unless OpenOCD was explicitly configured with the
‘--enable-oocd_trace’ option. You probably don’t want to configure it unless
you’ve built the appropriate prototype hardware; it’s proof-of-concept software.
oocd_trace
Use the ‘oocd_trace’ driver if you are configuring an ETM that’s connected to an
off-chip trace connector.
oocd_trace config target tty
[Config Command]
Associates the ETM for target with a trace driver which collects data through
the serial port tty.
oocd_trace resync
[Command]
Re-synchronizes with the capture clock.
oocd_trace status
Reports whether the capture clock is locked or not.
[Command]
Chapter 16: Architecture and Core Commands
100
16.2 Generic ARM
These commands should be available on all ARM processors. They are available in addition
to other core-specific commands that may be available.
arm core_state [‘arm’|‘thumb’]
[Command]
Displays the core state, optionally changing it to process either ‘arm’ or ‘thumb’ instructions. The target may later be resumed in the currently set core state. (Processors may also support the Jazelle state, but that is not currently supported in
OpenOCD.)
arm disassemble address [count [‘thumb’]]
[Command]
Disassembles count instructions starting at address. If count is not specified, a single
instruction is disassembled. If ‘thumb’ is specified, or the low bit of the address is set,
Thumb2 (mixed 16/32-bit) instructions are used; else ARM (32-bit) instructions are
used. (Processors may also support the Jazelle state, but those instructions are not
currently understood by OpenOCD.)
Note that all Thumb instructions are Thumb2 instructions, so older processors (without Thumb2 support) will still see correct disassembly of Thumb code. Also, ThumbEE opcodes are the same as Thumb2, with a handful of exceptions. ThumbEE
disassembly currently has no explicit support.
arm mcr pX op1 CRn CRm op2 value
[Command]
Write value to a coprocessor pX register passing parameters CRn, CRm, opcodes
opc1 and opc2, and using the MCR instruction. (Parameter sequence matches the
ARM instruction, but omits an ARM register.)
arm mrc pX coproc op1 CRn CRm op2
[Command]
Read a coprocessor pX register passing parameters CRn, CRm, opcodes opc1 and
opc2, and the MRC instruction. Returns the result so it can be manipulated by
Jim scripts. (Parameter sequence matches the ARM instruction, but omits an ARM
register.)
[Command]
Display a table of all banked core registers, fetching the current value from every core
mode if necessary.
arm reg
arm semihosting [‘enable’|‘disable’]
[Command]
Display status of semihosting, after optionally changing that status.
Semihosting allows for code executing on an ARM target to use the I/O facilities on
the host computer i.e. the system where OpenOCD is running. The target application
must be linked against a library implementing the ARM semihosting convention that
forwards operation requests by using a special SVC instruction that is trapped at the
Supervisor Call vector by OpenOCD.
16.3 ARMv4 and ARMv5 Architecture
The ARMv4 and ARMv5 architectures are widely used in embedded systems, and introduced core parts of the instruction set in use today. That includes the Thumb instruction
set, introduced in the ARMv4T variant.
Chapter 16: Architecture and Core Commands
101
16.3.1 ARM7 and ARM9 specific commands
These commands are specific to ARM7 and ARM9 cores, like ARM7TDMI, ARM720T,
ARM9TDMI, ARM920T or ARM926EJ-S. They are available in addition to the ARM
commands, and any other core-specific commands that may be available.
arm7_9 dbgrq [‘enable’|‘disable’]
[Command]
Displays the value of the flag controlling use of the the EmbeddedIce DBGRQ signal
to force entry into debug mode, instead of breakpoints. If a boolean parameter is
provided, first assigns that flag.
This should be safe for all but ARM7TDMI-S cores (like NXP LPC). This feature
is enabled by default on most ARM9 cores, including ARM9TDMI, ARM920T, and
ARM926EJ-S.
arm7_9 dcc_downloads [‘enable’|‘disable’]
[Command]
Displays the value of the flag controlling use of the debug communications channel
(DCC) to write larger (>128 byte) amounts of memory. If a boolean parameter is
provided, first assigns that flag.
DCC downloads offer a huge speed increase, but might be unsafe, especially with
targets running at very low speeds. This command was introduced with OpenOCD
rev. 60, and requires a few bytes of working area.
arm7_9 fast_memory_access [‘enable’|‘disable’]
[Command]
Displays the value of the flag controlling use of memory writes and reads that don’t
check completion of the operation. If a boolean parameter is provided, first assigns
that flag.
This provides a huge speed increase, especially with USB JTAG cables (FT2232),
but might be unsafe if used with targets running at very low speeds, like the 32kHz
startup clock of an AT91RM9200.
16.3.2 ARM720T specific commands
These commands are available to ARM720T based CPUs, which are implementations of
the ARMv4T architecture based on the ARM7TDMI-S integer core. They are available in
addition to the ARM and ARM7/ARM9 commands.
arm720t cp15 opcode [value]
[Command]
DEPRECATED – avoid using this. Use the arm mrc or arm mcr commands instead.
Display cp15 register returned by the ARM instruction opcode; else if a value is
provided, that value is written to that register. The opcode should be the value of
either an MRC or MCR instruction.
16.3.3 ARM9 specific commands
ARM9-family cores are built around ARM9TDMI or ARM9E (including ARM9EJS) integer
processors. Such cores include the ARM920T, ARM926EJ-S, and ARM966.
arm9 vector_catch [‘all’|‘none’|list]
[Command]
Vector Catch hardware provides a sort of dedicated breakpoint for hardware events
such as reset, interrupt, and abort. You can use this to conserve normal breakpoint
Chapter 16: Architecture and Core Commands
102
resources, so long as you’re not concerned with code that branches directly to those
hardware vectors.
This always finishes by listing the current configuration. If parameters are provided, it
first reconfigures the vector catch hardware to intercept ‘all’ of the hardware vectors,
‘none’ of them, or a list with one or more of the following: ‘reset’ ‘undef’ ‘swi’ ‘pabt’
‘dabt’ ‘irq’ ‘fiq’.
16.3.4 ARM920T specific commands
These commands are available to ARM920T based CPUs, which are implementations of
the ARMv4T architecture built using the ARM9TDMI integer core. They are available in
addition to the ARM, ARM7/ARM9, and ARM9 commands.
[Command]
Print information about the caches found. This allows to see whether your target is
an ARM920T (2x16kByte cache) or ARM922T (2x8kByte cache).
arm920t cache_info
arm920t cp15 regnum [value]
[Command]
Display cp15 register regnum; else if a value is provided, that value is written to that
register. This uses "physical access" and the register number is as shown in bits 38..33
of table 9-9 in the ARM920T TRM. (Not all registers can be written.)
arm920t cp15i opcode [value [address]]
[Command]
DEPRECATED – avoid using this. Use the arm mrc or arm mcr commands instead.
Interpreted access using ARM instruction opcode, which should be the value of either
an MRC or MCR instruction (as shown tables 9-11, 9-12, and 9-13 in the ARM920T
TRM). If no value is provided, the result is displayed. Else if that value is written
using the specified address, or using zero if no other address is provided.
arm920t read_cache filename
[Command]
Dump the content of ICache and DCache to a file named ‘filename’.
arm920t read_mmu filename
[Command]
Dump the content of the ITLB and DTLB to a file named ‘filename’.
16.3.5 ARM926ej-s specific commands
These commands are available to ARM926ej-s based CPUs, which are implementations of
the ARMv5TEJ architecture based on the ARM9EJ-S integer core. They are available in
addition to the ARM, ARM7/ARM9, and ARM9 commands.
The Feroceon cores also support these commands, although they are not built from
ARM926ej-s designs.
arm926ejs cache_info
[Command]
Print information about the caches found.
16.3.6 ARM966E specific commands
These commands are available to ARM966 based CPUs, which are implementations of the
ARMv5TE architecture. They are available in addition to the ARM, ARM7/ARM9, and
ARM9 commands.
Chapter 16: Architecture and Core Commands
103
arm966e cp15 regnum [value]
[Command]
Display cp15 register regnum; else if a value is provided, that value is written to that
register. The six bit regnum values are bits 37..32 from table 7-2 of the ARM966E-S
TRM. There is no current control over bits 31..30 from that table, as required for
BIST support.
16.3.7 XScale specific commands
Some notes about the debug implementation on the XScale CPUs:
The XScale CPU provides a special debug-only mini-instruction cache (mini-IC) in which
exception vectors and target-resident debug handler code are placed by OpenOCD. In order
to get access to the CPU, OpenOCD must point vector 0 (the reset vector) to the entry of
the debug handler. However, this means that the complete first cacheline in the mini-IC is
marked valid, which makes the CPU fetch all exception handlers from the mini-IC, ignoring
the code in RAM.
To address this situation, OpenOCD provides the xscale vector_table command, which
allows the user to explicity write individual entries to either the high or low vector table
stored in the mini-IC.
It is recommended to place a pc-relative indirect branch in the vector table, and put the
branch destination somewhere in memory. Doing so makes sure the code in the vector table
stays constant regardless of code layout in memory:
_vectors:
ldr
pc,[pc,#0x100-8]
ldr
pc,[pc,#0x100-8]
ldr
pc,[pc,#0x100-8]
ldr
pc,[pc,#0x100-8]
ldr
pc,[pc,#0x100-8]
ldr
pc,[pc,#0x100-8]
ldr
pc,[pc,#0x100-8]
ldr
pc,[pc,#0x100-8]
.org 0x100
.long real_reset_vector
.long real_ui_handler
.long real_swi_handler
.long real_pf_abort
.long real_data_abort
.long 0 /* unused */
.long real_irq_handler
.long real_fiq_handler
Alternatively, you may choose to keep some or all of the mini-IC vector table entries synced
with those written to memory by your system software. The mini-IC can not be modified
while the processor is executing, but for each vector table entry not previously defined using
the xscale vector_table command, OpenOCD will copy the value from memory to the
mini-IC every time execution resumes from a halt. This is done for both high and low
vector tables (although the table not in use may not be mapped to valid memory, and in
this case that copy operation will silently fail). This means that you will need to briefly
halt execution at some strategic point during system start-up; e.g., after the software has
Chapter 16: Architecture and Core Commands
104
initialized the vector table, but before exceptions are enabled. A breakpoint can be used to
accomplish this once the appropriate location in the start-up code has been identified. A
watchpoint over the vector table region is helpful in finding the location if you’re not sure.
Note that the same situation exists any time the vector table is modified by the system
software.
The debug handler must be placed somewhere in the address space using the xscale
debug_handler command. The allowed locations for the debug handler are either (0x800 0x1fef800) or (0xfe000800 - 0xfffff800). The default value is 0xfe000800.
XScale has resources to support two hardware breakpoints and two watchpoints. However,
the following restrictions on watchpoint functionality apply: (1) the value and mask arguments to the wp command are not supported, (2) the watchpoint length must be a power
of two and not less than four, and can not be greater than the watchpoint address, and
(3) a watchpoint with a length greater than four consumes all the watchpoint hardware
resources. This means that at any one time, you can have enabled either two watchpoints
with a length of four, or one watchpoint with a length greater than four.
These commands are available to XScale based CPUs, which are implementations of the
ARMv5TE architecture.
xscale analyze_trace
[Command]
Displays the contents of the trace buffer.
xscale cache_clean_address address
[Command]
Changes the address used when cleaning the data cache.
xscale cache_info
[Command]
Displays information about the CPU caches.
xscale cp15 regnum [value]
[Command]
Display cp15 register regnum; else if a value is provided, that value is written to that
register.
xscale debug_handler target address
[Command]
Changes the address used for the specified target’s debug handler.
xscale dcache [‘enable’|‘disable’]
[Command]
Enables or disable the CPU’s data cache.
xscale dump_trace filename
[Command]
Dumps the raw contents of the trace buffer to ‘filename’.
xscale icache [‘enable’|‘disable’]
[Command]
Enables or disable the CPU’s instruction cache.
xscale mmu [‘enable’|‘disable’]
[Command]
Enables or disable the CPU’s memory management unit.
xscale trace_buffer [‘enable’|‘disable’ [‘fill’ [n] | ‘wrap’]]
[Command]
Displays the trace buffer status, after optionally enabling or disabling the trace buffer
and modifying how it is emptied.
Chapter 16: Architecture and Core Commands
105
xscale trace_image filename [offset [type]]
[Command]
Opens a trace image from ‘filename’, optionally rebasing its segment addresses by
offset. The image type may be one of ‘bin’ (binary), ‘ihex’ (Intel hex), ‘elf’ (ELF
file), ‘s19’ (Motorola s19), ‘mem’, or ‘builder’.
xscale vector_catch [mask]
[Command]
Display a bitmask showing the hardware vectors to catch. If the optional parameter
is provided, first set the bitmask to that value.
The mask bits correspond with bit 16..23 in the DCSR:
0x01
0x02
0x04
0x08
0x10
0x20
0x40
0x80
Trap Reset
Trap Undefined Instructions
Trap Software Interrupt
Trap Prefetch Abort
Trap Data Abort
reserved
Trap IRQ
Trap FIQ
xscale vector_table [(‘low’|‘high’) index value]
[Command]
Set an entry in the mini-IC vector table. There are two tables: one for low vectors (at
0x00000000), and one for high vectors (0xFFFF0000), each holding the 8 exception
vectors. index can be 1-7, because vector 0 points to the debug handler entry and
can not be overwritten. value holds the 32-bit opcode that is placed in the mini-IC.
Without arguments, the current settings are displayed.
16.4 ARMv6 Architecture
16.4.1 ARM11 specific commands
arm11 memwrite burst [‘enable’|‘disable’]
[Command]
Displays the value of the memwrite burst-enable flag, which is enabled by default. If
a boolean parameter is provided, first assigns that flag. Burst writes are only used
for memory writes larger than 1 word. They improve performance by assuming that
the CPU has read each data word over JTAG and completed its write before the next
word arrives, instead of polling for a status flag to verify that completion. This is
usually safe, because JTAG runs much slower than the CPU.
arm11 memwrite error_fatal [‘enable’|‘disable’]
[Command]
Displays the value of the memwrite error fatal flag, which is enabled by default. If
a boolean parameter is provided, first assigns that flag. When set, certain memory
write errors cause earlier transfer termination.
arm11 step_irq_enable [‘enable’|‘disable’]
[Command]
Displays the value of the flag controlling whether IRQs are enabled during single
stepping; they are disabled by default. If a boolean parameter is provided, first
assigns that.
Chapter 16: Architecture and Core Commands
106
arm11 vcr [value]
[Command]
Displays the value of the Vector Catch Register (VCR), coprocessor 14 register 7. If
value is defined, first assigns that.
Vector Catch hardware provides dedicated breakpoints for certain hardware events.
The specific bit values are core-specific (as in fact is using coprocessor 14 register 7
itself) but all current ARM11 cores except the ARM1176 use the same six bits.
16.5 ARMv7 Architecture
16.5.1 ARMv7 Debug Access Port (DAP) specific commands
These commands are specific to ARM architecture v7 Debug Access Port (DAP), included
on Cortex-M3 and Cortex-A8 systems. They are available in addition to other core-specific
commands that may be available.
dap apid [num]
[Command]
Displays ID register from AP num, defaulting to the currently selected AP.
dap apsel [num]
[Command]
Select AP num, defaulting to 0.
dap baseaddr [num]
[Command]
Displays debug base address from MEM-AP num, defaulting to the currently selected
AP.
dap info [num]
[Command]
Displays the ROM table for MEM-AP num, defaulting to the currently selected AP.
dap memaccess [value]
[Command]
Displays the number of extra tck cycles in the JTAG idle to use for MEM-AP memory
bus access [0-255], giving additional time to respond to reads. If value is defined, first
assigns that.
16.5.2 Cortex-M3 specific commands
cortex_m3 maskisr (‘auto’|‘on’|‘off’)
[Command]
Control masking (disabling) interrupts during target step/resume.
The ‘auto’ option handles interrupts during stepping a way they get served but don’t
disturb the program flow. The step command first allows pending interrupt handlers
to execute, then disables interrupts and steps over the next instruction where the core
was halted. After the step interrupts are enabled again. If the interrupt handlers don’t
complete within 500ms, the step command leaves with the core running.
Note that a free breakpoint is required for the ‘auto’ option. If no breakpoint is
available at the time of the step, then the step is taken with interrupts enabled, i.e.
the same way the ‘off’ option does.
Default is ‘auto’.
Chapter 16: Architecture and Core Commands
107
cortex_m3 vector_catch [‘all’|‘none’|list]
[Command]
Vector Catch hardware provides dedicated breakpoints for certain hardware events.
Parameters request interception of ‘all’ of these hardware event vectors, ‘none’
of them, or one or more of the following: ‘hard_err’ for a HardFault exception;
‘mm_err’ for a MemManage exception; ‘bus_err’ for a BusFault exception; ‘irq_err’,
‘state_err’, ‘chk_err’, or ‘nocp_err’ for various UsageFault exceptions; or ‘reset’.
If NVIC setup code does not enable them, MemManage, BusFault, and UsageFault
exceptions are mapped to HardFault. UsageFault checks for divide-by-zero and unaligned access must also be explicitly enabled.
This finishes by listing the current vector catch configuration.
cortex_m3 reset_config (‘srst’|‘sysresetreq’|‘vectreset’)
[Command]
Control reset handling. The default ‘srst’ is to use srst if fitted, otherwise fallback
to ‘vectreset’.
− ‘srst’ use hardware srst if fitted otherwise fallback to ‘vectreset’.
− ‘sysresetreq’ use NVIC SYSRESETREQ to reset system.
− ‘vectreset’ use NVIC VECTRESET to reset system.
Using ‘vectreset’ is a safe option for all current Cortex-M3 cores. This however has
the disadvantage of only resetting the core, all peripherals are uneffected. A solution
would be to use a reset-init event handler to manually reset the peripherals. See
[Target Events], page 64.
16.6 Software Debug Messages and Tracing
OpenOCD can process certain requests from target software, when the target uses appropriate libraries. The most powerful mechanism is semihosting, but there is also a lighter
weight mechanism using only the DCC channel.
Currently target_request debugmsgs is supported only for ‘arm7_9’ and ‘cortex_m3’
cores. These messages are received as part of target polling, so you need to have poll
on active to receive them. They are intrusive in that they will affect program execution
times. If that is a problem, see [ARM Hardware Tracing], page 96.
See ‘libdcc’ in the contrib dir for more details. In addition to sending strings, characters,
and arrays of various size integers from the target, ‘libdcc’ also exports a software trace
point mechanism. The target being debugged may issue trace messages which include a
24-bit trace point number. Trace point support includes two distinct mechanisms, each
supported by a command:
• History ... A circular buffer of trace points can be set up, and then displayed at any
time. This tracks where code has been, which can be invaluable in finding out how
some fault was triggered.
The buffer may overflow, since it collects records continuously. It may be useful to use
some of the 24 bits to represent a particular event, and other bits to hold data.
• Counting ... An array of counters can be set up, and then displayed at any time. This
can help establish code coverage and identify hot spots.
The array of counters is directly indexed by the trace point number, so trace points
with higher numbers are not counted.
Chapter 16: Architecture and Core Commands
108
Linux-ARM kernels have a “Kernel low-level debugging via EmbeddedICE DCC channel”
option (CONFIG DEBUG ICEDCC, depends on CONFIG DEBUG LL) which uses this
mechanism to deliver messages before a serial console can be activated. This is not the
same format used by ‘libdcc’. Other software, such as the U-Boot boot loader, sometimes
does the same thing.
target_request debugmsgs [‘enable’|‘disable’|‘charmsg’]
[Command]
Displays current handling of target DCC message requests. These messages may be
sent to the debugger while the target is running. The optional ‘enable’ and ‘charmsg’
parameters both enable the messages, while ‘disable’ disables them.
With ‘charmsg’ the DCC words each contain one character, as used by Linux with
CONFIG DEBUG ICEDCC; otherwise the libdcc format is used.
trace history [‘clear’|count]
[Command]
With no parameter, displays all the trace points that have triggered in the order they
triggered. With the parameter ‘clear’, erases all current trace history records. With
a count parameter, allocates space for that many history records.
trace point [‘clear’|identifier]
[Command]
With no parameter, displays all trace point identifiers and how many times they
have been triggered. With the parameter ‘clear’, erases all current trace point counters. With a numeric identifier parameter, creates a new a trace point counter and
associates it with that identifier.
Important: The identifier and the trace point number are not related except by this
command. These trace point numbers always start at zero (from server startup, or
after trace point clear) and count up from there.
Chapter 17: JTAG Commands
109
17 JTAG Commands
Most general purpose JTAG commands have been presented earlier. (See [JTAG Speed],
page 46, Chapter 9 [Reset Configuration], page 48, and Chapter 10 [TAP Declaration],
page 53.) Lower level JTAG commands, as presented here, may be needed to work with
targets which require special attention during operations such as reset or initialization.
To use these commands you will need to understand some of the basics of JTAG, including:
• A JTAG scan chain consists of a sequence of individual TAP devices such as a CPUs.
• Control operations involve moving each TAP through the same standard state machine
(in parallel) using their shared TMS and clock signals.
• Data transfer involves shifting data through the chain of instruction or data registers
of each TAP, writing new register values while the reading previous ones.
• Data register sizes are a function of the instruction active in a given TAP, while instruction register sizes are fixed for each TAP. All TAPs support a BYPASS instruction
with a single bit data register.
• The way OpenOCD differentiates between TAP devices is by shifting different instructions into (and out of) their instruction registers.
17.1 Low Level JTAG Commands
These commands are used by developers who need to access JTAG instruction or data
registers, possibly controlling the order of TAP state transitions. If you’re not debugging
OpenOCD internals, or bringing up a new JTAG adapter or a new type of TAP device
(like a CPU or JTAG router), you probably won’t need to use these commands. In a debug
session that doesn’t use JTAG for its transport protocol, these commands are not available.
drscan tap [numbits value]+ [‘-endstate’ tap state]
[Command]
Loads the data register of tap with a series of bit fields that specify the entire register.
Each field is numbits bits long with a numeric value (hexadecimal encouraged). The
return value holds the original value of each of those fields.
For example, a 38 bit number might be specified as one field of 32 bits then one of
6 bits. For portability, never pass fields which are more than 32 bits long. Many
OpenOCD implementations do not support 64-bit (or larger) integer values.
All TAPs other than tap must be in BYPASS mode. The single bit in their data
registers does not matter.
When tap state is specified, the JTAG state machine is left in that state. For example
drpause might be specified, so that more instructions can be issued before re-entering
the run/idle state. If the end state is not specified, the run/idle state is entered.
Warning: OpenOCD does not record information about data register
lengths, so it is important that you get the bit field lengths right. Remember that different JTAG instructions refer to different data registers,
which may have different lengths. Moreover, those lengths may not be
fixed; the SCAN N instruction can change the length of the register accessed by the INTEST instruction (by connecting a different scan chain).
Chapter 17: JTAG Commands
110
[Command]
Returns the number of times the JTAG queue has been flushed. This may be used
for performance tuning.
For example, flushing a queue over USB involves a minimum latency, often several
milliseconds, which does not change with the amount of data which is written. You
may be able to identify performance problems by finding tasks which waste bandwidth
by flushing small transfers too often, instead of batching them into larger operations.
flush_count
irscan [tap instruction]+ [‘-endstate’ tap state]
[Command]
For each tap listed, loads the instruction register with its associated numeric
instruction. (The number of bits in that instruction may be displayed using the
scan_chain command.) For other TAPs, a BYPASS instruction is loaded.
When tap state is specified, the JTAG state machine is left in that state. For example
irpause might be specified, so the data register can be loaded before re-entering the
run/idle state. If the end state is not specified, the run/idle state is entered.
Note: OpenOCD currently supports only a single field for instruction register values, unlike data register values. For TAPs where the instruction
register length is more than 32 bits, portable scripts currently must issue
only BYPASS instructions.
jtag_reset trst srst
[Command]
Set values of reset signals. The trst and srst parameter values may be ‘0’, indicating
that reset is inactive (pulled or driven high), or ‘1’, indicating it is active (pulled or
driven low). The reset_config command should already have been used to configure
how the board and JTAG adapter treat these two signals, and to say if either signal
is even present. See Chapter 9 [Reset Configuration], page 48.
Note that TRST is specially handled. It actually signifies JTAG’s reset state. So if
the board doesn’t support the optional TRST signal, or it doesn’t support it along
with the specified SRST value, JTAG reset is triggered with TMS and TCK signals
instead of the TRST signal. And no matter how that JTAG reset is triggered, once the
scan chain enters reset with TRST inactive, TAP post-reset events are delivered
to all TAPs with handlers for that event.
pathmove start state [next state ...]
[Command]
Start by moving to start state, which must be one of the stable states. Unless it is the
only state given, this will often be the current state, so that no TCK transitions are
needed. Then, in a series of single state transitions (conforming to the JTAG state
machine) shift to each next state in sequence, one per TCK cycle. The final state
must also be stable.
[Command]
Move to the run/idle state, and execute at least num cycles of the JTAG clock
(TCK). Instructions often need some time to execute before they take effect.
runtest num_cycles
verify_ircapture (‘enable’|‘disable’)
[Command]
Verify values captured during ircapture and returned during IR scans. Default
is enabled, but this can be overridden by verify_jtag. This flag is ignored when
validating JTAG chain configuration.
Chapter 17: JTAG Commands
111
verify_jtag (‘enable’|‘disable’)
[Command]
Enables verification of DR and IR scans, to help detect programming errors. For IR
scans, verify_ircapture must also be enabled. Default is enabled.
17.2 TAP state names
The tap state names used by OpenOCD in the drscan, irscan, and pathmove commands
are the same as those used in SVF boundary scan documents, except that SVF uses idle
instead of run/idle.
• RESET ... stable (with TMS high); acts as if TRST were pulsed
• RUN/IDLE ... stable; don’t assume this always means IDLE
• DRSELECT
• DRCAPTURE
• DRSHIFT ... stable; TDI/TDO shifting through the data register
• DREXIT1
• DRPAUSE ... stable; data register ready for update or more shifting
• DREXIT2
• DRUPDATE
• IRSELECT
• IRCAPTURE
• IRSHIFT ... stable; TDI/TDO shifting through the instruction register
• IREXIT1
• IRPAUSE ... stable; instruction register ready for update or more shifting
• IREXIT2
• IRUPDATE
Note that only six of those states are fully “stable” in the face of TMS fixed (low except
for reset) and a free-running JTAG clock. For all the others, the next TCK transition
changes to a new state.
• From drshift and irshift, clock transitions will produce side effects by changing
register contents. The values to be latched in upcoming drupdate or irupdate states
may not be as expected.
• run/idle, drpause, and irpause are reasonable choices after drscan or irscan commands, since they are free of JTAG side effects.
• run/idle may have side effects that appear at non-JTAG levels, such as advancing
the ARM9E-S instruction pipeline. Consult the documentation for the TAP(s) you are
working with.
Chapter 18: Boundary Scan Commands
112
18 Boundary Scan Commands
One of the original purposes of JTAG was to support boundary scan based hardware testing.
Although its primary focus is to support On-Chip Debugging, OpenOCD also includes some
boundary scan commands.
18.1 SVF: Serial Vector Format
The Serial Vector Format, better known as SVF, is a way to represent JTAG test patterns
in text files. In a debug session using JTAG for its transport protocol, OpenOCD supports
running such test files.
svf filename [‘quiet’]
[Command]
This issues a JTAG reset (Test-Logic-Reset) and then runs the SVF script from
‘filename’. Unless the ‘quiet’ option is specified, each command is logged before it
is executed.
18.2 XSVF: Xilinx Serial Vector Format
The Xilinx Serial Vector Format, better known as XSVF, is a binary representation of SVF
which is optimized for use with Xilinx devices. In a debug session using JTAG for its
transport protocol, OpenOCD supports running such test files.
Important: Not all XSVF commands are supported.
xsvf (tapname|‘plain’) filename [‘virt2’] [‘quiet’]
[Command]
This issues a JTAG reset (Test-Logic-Reset) and then runs the XSVF script from
‘filename’. When a tapname is specified, the commands are directed at that TAP.
When ‘virt2’ is specified, the xruntest command counts are interpreted as TCK
cycles instead of microseconds. Unless the ‘quiet’ option is specified, messages are
logged for comments and some retries.
The OpenOCD sources also include two utility scripts for working with XSVF; they are not
currently installed after building the software. You may find them useful:
• svf2xsvf ... converts SVF files into the extended XSVF syntax understood by the xsvf
command; see notes below.
• xsvfdump ... converts XSVF files into a text output format; understands the OpenOCD
extensions.
The input format accepts a handful of non-standard extensions. These include three opcodes corresponding to SVF extensions from Lattice Semiconductor (LCOUNT, LDELAY,
LDSR), and two opcodes supporting a more accurate translation of SVF (XTRST, XWAITSTATE). If xsvfdump shows a file is using those opcodes, it probably will not be usable with
other XSVF tools.
Chapter 19: TFTP
113
19 TFTP
If OpenOCD runs on an embedded host(as ZY1000 does), then TFTP can be used to access
files on PCs (either the developer’s PC or some other PC).
The way this works on the ZY1000 is to prefix a filename by "/tftp/ip/" and append the
TFTP path on the TFTP server (tftpd). For example,
load_image /tftp/10.0.0.96/c:\temp\abc.elf
will load c:\temp\abc.elf from the developer pc (10.0.0.96) into memory as if the file was
hosted on the embedded host.
In order to achieve decent performance, you must choose a TFTP server that supports a
packet size bigger than the default packet size (512 bytes). There are numerous TFTP
servers out there (free and commercial) and you will have to do a bit of googling to find
something that fits your requirements.
Chapter 20: GDB and OpenOCD
114
20 GDB and OpenOCD
OpenOCD complies with the remote gdbserver protocol, and as such can be used to debug
remote targets. Setting up GDB to work with OpenOCD can involve several components:
• The OpenOCD server support for GDB may need to be configured. See [GDB Configuration], page 35.
• GDB’s support for OpenOCD may need configuration, as shown in this chapter.
• If you have a GUI environment like Eclipse, that also will probably need to be configured.
Of course, the version of GDB you use will need to be one which has been built to know
about the target CPU you’re using. It’s probably part of the tool chain you’re using. For
example, if you are doing cross-development for ARM on an x86 PC, instead of using the
native x86 gdb command you might use arm-none-eabi-gdb if that’s the tool chain used
to compile your code.
20.1 Connecting to GDB
Use GDB 6.7 or newer with OpenOCD if you run into trouble. For instance GDB 6.3 has
a known bug that produces bogus memory access errors, which has since been fixed; see
http://osdir.com/ml/gdb.bugs.discuss/2004-12/msg00018.html
OpenOCD can communicate with GDB in two ways:
1. A socket (TCP/IP) connection is typically started as follows:
target remote localhost:3333
This would cause GDB to connect to the gdbserver on the local pc using port 3333.
2. A pipe connection is typically started as follows:
target remote | openocd -c "gdb_port pipe; log_output openocd.log"
This would cause GDB to run OpenOCD and communicate using pipes (stdin/stdout).
Using this method has the advantage of GDB starting/stopping OpenOCD for the
debug session. log output sends the log output to a file to ensure that the pipe is not
saturated when using higher debug level outputs.
To list the available OpenOCD commands type monitor help on the GDB command line.
20.2 Sample GDB session startup
With the remote protocol, GDB sessions start a little differently than they do when you’re
debugging locally. Here’s an examples showing how to start a debug session with a small
ARM program. In this case the program was linked to be loaded into SRAM on a CortexM3. Most programs would be written into flash (address 0) and run from there.
$ arm-none-eabi-gdb example.elf
(gdb) target remote localhost:3333
Remote debugging using localhost:3333
...
(gdb) monitor reset halt
...
Chapter 20: GDB and OpenOCD
115
(gdb) load
Loading section .vectors, size 0x100 lma 0x20000000
Loading section .text, size 0x5a0 lma 0x20000100
Loading section .data, size 0x18 lma 0x200006a0
Start address 0x2000061c, load size 1720
Transfer rate: 22 KB/sec, 573 bytes/write.
(gdb) continue
Continuing.
...
You could then interrupt the GDB session to make the program break, type where to show
the stack, list to show the code around the program counter, step through code, set
breakpoints or watchpoints, and so on.
20.3 Configuring GDB for OpenOCD
OpenOCD supports the gdb ‘qSupported’ packet, this enables information to be sent by
the GDB remote server (i.e. OpenOCD) to GDB. Typical information includes packet size
and the device’s memory map. You do not need to configure the packet size by hand, and
the relevant parts of the memory map should be automatically set up when you declare
(NOR) flash banks.
However, there are other things which GDB can’t currently query. You may need to set
those up by hand. As OpenOCD starts up, you will often see a line reporting something
like:
Info : lm3s.cpu: hardware has 6 breakpoints, 4 watchpoints
You can pass that information to GDB with these commands:
set remote hardware-breakpoint-limit 6
set remote hardware-watchpoint-limit 4
With that particular hardware (Cortex-M3) the hardware breakpoints only work for code
running from flash memory. Most other ARM systems do not have such restrictions.
Another example of useful GDB configuration came from a user who found that single
stepping his Cortex-M3 didn’t work well with IRQs and an RTOS until he told GDB to
disable the IRQs while stepping:
define hook-step
mon cortex_m3 maskisr on
end
define hookpost-step
mon cortex_m3 maskisr off
end
Rather than typing such commands interactively, you may prefer to save them in a file and
have GDB execute them as it starts, perhaps using a ‘.gdbinit’ in your project directory
or starting GDB using gdb -x filename.
20.4 Programming using GDB
By default the target memory map is sent to GDB. This can be disabled by the following
OpenOCD configuration option:
Chapter 20: GDB and OpenOCD
116
gdb_memory_map disable
For this to function correctly a valid flash configuration must also be set in OpenOCD. For
faster performance you should also configure a valid working area.
Informing GDB of the memory map of the target will enable GDB to protect any flash
areas of the target and use hardware breakpoints by default. This means that the
OpenOCD option gdb_breakpoint_override is not required when using a memory map.
See [gdb breakpoint override], page 35.
To view the configured memory map in GDB, use the GDB command ‘info mem’ All other
unassigned addresses within GDB are treated as RAM.
GDB 6.8 and higher set any memory area not in the memory map as inaccessible. This can
be changed to the old behaviour by using the following GDB command
set mem inaccessible-by-default off
If gdb_flash_program enable is also used, GDB will be able to program any flash memory
using the vFlash interface.
GDB will look at the target memory map when a load command is given, if any areas to
be programmed lie within the target flash area the vFlash packets will be used.
If the target needs configuring before GDB programming, an event script can be executed:
$_TARGETNAME configure -event EVENTNAME BODY
To verify any flash programming the GDB command ‘compare-sections’ can be used.
20.5 Using openocd SMP with GDB
For SMP support following GDB serial protocol packet have been defined :
• j - smp status request
• J - smp set request
OpenOCD implements :
• ‘jc’ packet for reading core id displayed by GDB connection. Reply is ‘XXXXXXXX’ (8
hex digits giving core id) or ‘E01’ for target not smp.
• ‘JcXXXXXXXX’ (8 hex digits) packet for setting core id displayed at next GDB continue
(core id -1 is reserved for returning to normal resume mode). Reply ‘E01’ for target
not smp or ‘OK’ on success.
Handling of this packet within GDB can be done :
• by the creation of an internal variable (i.e ‘_core’) by mean of function
allocate computed value allowing following GDB command.
set $_core 1
#Jc01 packet is sent
print $_core
#jc packet is sent and result is affected in $
• by the usage of GDB maintenance command as described in following example (2 cpus
in SMP with core id 0 and 1 see [Define CPU targets working in SMP], page 29).
# toggle0 : force display of coreid 0
define toggle0
Chapter 20: GDB and OpenOCD
maint packet Jc0
continue
main packet Jc-1
end
# toggle1 : force display of coreid 1
define toggle1
maint packet Jc1
continue
main packet Jc-1
end
117
Chapter 21: Tcl Scripting API
118
21 Tcl Scripting API
21.1 API rules
The commands are stateless. E.g. the telnet command line has a concept of currently active
target, the Tcl API proc’s take this sort of state information as an argument to each proc.
There are three main types of return values: single value, name value pair list and lists.
Name value pair. The proc ’foo’ below returns a name/value pair list.
>
>
>
>
set
set
set
set
foo(me) Duane
foo(you) Oyvind
foo(mouse) Micky
foo(duck) Donald
If one does this:
>
set foo
The result is:
me Duane you Oyvind mouse Micky duck Donald
Thus, to get the names of the associative array is easy:
foreach
{ name value }
[set foo]
{
puts "Name: $name, Value: $value"
}
Lists returned must be relatively small. Otherwise a range should be passed in to the proc
in question.
21.2 Internal low-level Commands
By low-level, the intent is a human would not directly use these commands.
Low-level commands are (should be) prefixed with "ocd ", e.g. ocd_flash_banks is the
low level API upon which flash banks is implemented.
• mem2array <varname> <width> <addr> <nelems>
Read memory and return as a Tcl array for script processing
• array2mem <varname> <width> <addr> <nelems>
Convert a Tcl array to memory locations and write the values
• ocd flash banks <driver> <base> <size> <chip width> <bus width> <target> [‘driver
options’ ...]
Return information about the flash banks
OpenOCD commands can consist of two words, e.g. "flash banks". The ‘startup.tcl’
"unknown" proc will translate this into a Tcl proc called "flash banks".
Chapter 21: Tcl Scripting API
119
21.3 OpenOCD specific Global Variables
Real Tcl has ::tcl platform(), and platform::identify, and many other variables. JimTCL, as
implemented in OpenOCD creates $ocd HOSTOS which holds one of the following values:
• cygwin Running under Cygwin
• darwin Darwin (Mac-OS) is the underlying operating sytem.
• freebsd Running under FreeBSD
• linux Linux is the underlying operating sytem
• mingw32 Running under MingW32
• winxx Built using Microsoft Visual Studio
• other Unknown, none of the above.
Note: ’winxx’ was choosen because today (March-2009) no distinction is made between
Win32 and Win64.
Note: We should add support for a variable like Tcl variable tcl_
platform(platform), it should be called jim_platform (because it is jim,
not real tcl).
Chapter 22: FAQ
120
22 FAQ
1. RTCK, also known as: Adaptive Clocking - What is it?
In digital circuit design it is often refered to as “clock synchronisation” the JTAG
interface uses one clock (TCK or TCLK) operating at some speed, your CPU target is
operating at another. The two clocks are not synchronised, they are “asynchronous”
In order for the two to work together they must be synchronised well enough to work;
JTAG can’t go ten times faster than the CPU, for example. There are 2 basic options:
1. Use a special "adaptive clocking" circuit to change the JTAG clock rate to match
what the CPU currently supports.
2. The JTAG clock must be fixed at some speed that’s enough slower than the CPU
clock that all TMS and TDI transitions can be detected.
Does this really matter? For some chips and some situations, this is a non-issue, like
a 500MHz ARM926 with a 5 MHz JTAG link; the CPU has no difficulty keeping up
with JTAG. Startup sequences are often problematic though, as are other situations
where the CPU clock rate changes (perhaps to save power).
For example, Atmel AT91SAM chips start operation from reset with a 32kHz system
clock. Boot firmware may activate the main oscillator and PLL before switching to a
faster clock (perhaps that 500 MHz ARM926 scenario). If you’re using JTAG to debug
that startup sequence, you must slow the JTAG clock to sometimes 1 to 4kHz. After
startup completes, JTAG can use a faster clock.
Consider also debugging a 500MHz ARM926 hand held battery powered device that
enters a low power “deep sleep” mode, at 32kHz CPU clock, between keystrokes unless
it has work to do. When would that 5 MHz JTAG clock be usable?
Solution #1 - A special circuit
In order to make use of this, your CPU, board, and JTAG adapter must all support
the RTCK feature. Not all of them support this; keep reading!
The RTCK ("Return TCK") signal in some ARM chips is used to help with this
problem. ARM has a good description of the problem described at this link: http://
www.arm.com/support/faqdev/4170.html [checked 28/nov/2008]. Link title: “How
does the JTAG synchronisation logic work? / how does adaptive clocking work?”.
The nice thing about adaptive clocking is that “battery powered hand held device
example” - the adaptiveness works perfectly all the time. One can set a break point
or halt the system in the deep power down code, slow step out until the system speeds
up.
Note that adaptive clocking may also need to work at the board level, when a boardlevel scan chain has multiple chips. Parallel clock voting schemes are good way to
implement this, both within and between chips, and can easily be implemented with a
CPLD. It’s not difficult to have logic fan a module’s input TCK signal out to each TAP
in the scan chain, and then wait until each TAP’s RTCK comes back with the right
polarity before changing the output RTCK signal. Texas Instruments makes some
clock voting logic available for free (with no support) in VHDL form; see http://
tiexpressdsp.com/index.php/Adaptive_Clocking
Chapter 22: FAQ
121
Solution #2 - Always works - but may be slower
Often this is a perfectly acceptable solution.
In most simple terms: Often the JTAG clock must be 1/10 to 1/12 of the target clock
speed. But what that “magic division” is varies depending on the chips on your board.
ARM rule of thumb Most ARM based systems require an 6:1 division; ARM11 cores
use an 8:1 division. Xilinx rule of thumb is 1/12 the clock speed.
Note: most full speed FT2232 based JTAG adapters are limited to a maximum of
6MHz. The ones using USB high speed chips (FT2232H) often support faster clock
rates (and adaptive clocking).
You can still debug the ’low power’ situations - you just need to either use a fixed and
very slow JTAG clock rate ... or else manually adjust the clock speed at every step.
(Adjusting is painful and tedious, and is not always practical.)
It is however easy to “code your way around it” - i.e.: Cheat a little, have a special
debug mode in your application that does a “high power sleep”. If you are careful 98% of your problems can be debugged this way.
Note that on ARM you may need to avoid using the wait for interrupt operation in
your idle loops even if you don’t otherwise change the CPU clock rate. That operation
gates the CPU clock, and thus the JTAG clock; which prevents JTAG access. One
consequence is not being able to halt cores which are executing that wait for interrupt
operation.
To set the JTAG frequency use the command:
# Example: 1.234MHz
adapter_khz 1234
2. Win32 Pathnames Why don’t backslashes work in Windows paths?
OpenOCD uses Tcl and a backslash is an escape char. Use { and } around Windows
filenames.
> echo \a
> echo {\a}
\a
> echo "\a"
>
3. Missing: cygwin1.dll OpenOCD complains about a missing cygwin1.dll.
Make sure you have Cygwin installed, or at least a version of OpenOCD that claims
to come with all the necessary DLLs. When using Cygwin, try launching OpenOCD
from the Cygwin shell.
4. Breakpoint Issue I’m trying to set a breakpoint using GDB (or a frontend like
Insight or Eclipse), but OpenOCD complains that "Info: arm7 9 common.c:213
arm7 9 add breakpoint(): sw breakpoint requested, but software breakpoints not
enabled".
GDB issues software breakpoints when a normal breakpoint is requested, or to implement source-line single-stepping. On ARMv4T systems, like ARM7TDMI, ARM720T
Chapter 22: FAQ
5.
6.
7.
8.
9.
122
or ARM920T, software breakpoints consume one of the two available hardware breakpoints.
LPC2000 Flash When erasing or writing LPC2000 on-chip flash, the operation fails at
random.
Make sure the core frequency specified in the ‘flash lpc2000’ line matches the clock
at the time you’re programming the flash. If you’ve specified the crystal’s frequency,
make sure the PLL is disabled. If you’ve specified the full core speed (e.g. 60MHz),
make sure the PLL is enabled.
Amontec Chameleon When debugging using an Amontec Chameleon in its JTAG Accelerator configuration, I keep getting "Error: amt jtagaccel.c:184 amt wait scan busy():
amt jtagaccel timed out while waiting for end of scan, rtck was disabled".
Make sure your PC’s parallel port operates in EPP mode. You might have to try
several settings in your PC BIOS (ECP, EPP, and different versions of those).
Data Aborts When debugging with OpenOCD and GDB (plain GDB, Insight, or
Eclipse), I get lots of "Error: arm7 9 common.c:1771 arm7 9 read memory(): memory
read caused data abort".
The errors are non-fatal, and are the result of GDB trying to trace stack frames beyond
the last valid frame. It might be possible to prevent this by setting up a proper "initial"
stack frame, if you happen to know what exactly has to be done, feel free to add this
here.
Simple: In your startup code - push 8 registers of zeros onto the stack before calling
main(). What GDB is doing is “climbing” the run time stack by reading various values
on the stack using the standard call frame for the target. GDB keeps going - until one of
2 things happen #1 an invalid frame is found, or #2 some huge number of stackframes
have been processed. By pushing zeros on the stack, GDB gracefully stops.
Debugging Interrupt Service Routines - In your ISR before you call your C code, do
the same - artifically push some zeros onto the stack, remember to pop them off when
the ISR is done.
Also note: If you have a multi-threaded operating system, they often do not in the
intrest of saving memory waste these few bytes. Painful...
JTAG Reset Config I get the following message in the OpenOCD console (or log file):
"Warning: arm7 9 common.c:679 arm7 9 assert reset(): srst resets test logic, too".
This warning doesn’t indicate any serious problem, as long as you don’t want to debug your core right out of reset. Your .cfg file specified ‘jtag_reset trst_and_srst
srst_pulls_trst’ to tell OpenOCD that either your board, your debugger or your
target uC (e.g. LPC2000) can’t assert the two reset signals independently. With this
setup, it’s not possible to halt the core right out of reset, everything else should work
fine.
USB Power When using OpenOCD in conjunction with Amontec JTAGkey and the
Yagarto toolchain (Eclipse, arm-elf-gcc, arm-elf-gdb), the debugging seems to be unstable. When single-stepping over large blocks of code, GDB and OpenOCD quit with
an error message. Is there a stability issue with OpenOCD?
No, this is not a stability issue concerning OpenOCD. Most users have solved this issue
by simply using a self-powered USB hub, which they connect their Amontec JTAGkey
Chapter 22: FAQ
123
to. Apparently, some computers do not provide a USB power supply stable enough for
the Amontec JTAGkey to be operated.
Laptops running on battery have this problem too...
10. USB Power When using the Amontec JTAGkey, sometimes OpenOCD crashes with the
following error messages: "Error: ft2232.c:201 ft2232 read(): FT Read returned: 4"
and "Error: ft2232.c:365 ft2232 send and recv(): couldn’t read from FT2232". What
does that mean and what might be the reason for this?
First of all, the reason might be the USB power supply. Try using a self-powered hub
instead of a direct connection to your computer. Secondly, the error code 4 corresponds
to an FT IO ERROR, which means that the driver for the FTDI USB chip ran into
some sort of error - this points us to a USB problem.
11. GDB Disconnects When using the Amontec JTAGkey, sometimes OpenOCD crashes
with the following error message: "Error: gdb server.c:101 gdb get char(): read:
10054". What does that mean and what might be the reason for this?
Error code 10054 corresponds to WSAECONNRESET, which means that the debugger
(GDB) has closed the connection to OpenOCD. This might be a GDB issue.
12. LPC2000 Flash In the configuration file in the section where flash device configurations are described, there is a parameter for specifying the clock frequency for
LPC2000 internal flash devices (e.g. ‘flash bank $_FLASHNAME lpc2000 0x0 0x40000
0 0 $_TARGETNAME lpc2000_v1 14746 calc_checksum’), which must be specified in
kilohertz. However, I do have a quartz crystal of a frequency that contains fractions
of kilohertz (e.g. 14,745,600 Hz, i.e. 14,745.600 kHz). Is it possible to specify real
numbers for the clock frequency?
No. The clock frequency specified here must be given as an integral number. However,
this clock frequency is used by the In-Application-Programming (IAP) routines of the
LPC2000 family only, which seems to be very tolerant concerning the given clock
frequency, so a slight difference between the specified clock frequency and the actual
clock frequency will not cause any trouble.
13. Command Order Do I have to keep a specific order for the commands in the configuration file?
Well, yes and no. Commands can be given in arbitrary order, yet the devices listed
for the JTAG scan chain must be given in the right order (jtag newdevice), with the
device closest to the TDO-Pin being listed first. In general, whenever objects of the
same type exist which require an index number, then these objects must be given in
the right order (jtag newtap, targets and flash banks - a target references a jtag newtap
and a flash bank references a target).
You can use the “scan chain” command to verify and display the tap order.
Also, some commands can’t execute until after init has been processed. Such commands include nand probe and everything else that needs to write to controller registers, perhaps for setting up DRAM and loading it with code.
14. JTAG TAP Order Do I have to declare the TAPS in some particular order?
Yes; whenever you have more than one, you must declare them in the same order used
by the hardware.
Chapter 22: FAQ
124
Many newer devices have multiple JTAG TAPs. For example: ST Microsystems
STM32 chips have two TAPs, a “boundary scan TAP” and “Cortex-M3” TAP. Example: The STM32 reference manual, Document ID: RM0008, Section 26.5, Figure
259, page 651/681, the “TDI” pin is connected to the boundary scan TAP, which then
connects to the Cortex-M3 TAP, which then connects to the TDO pin.
Thus, the proper order for the STM32 chip is: (1) The Cortex-M3, then (2) The
boundary scan TAP. If your board includes an additional JTAG chip in the scan chain
(for example a Xilinx CPLD or FPGA) you could place it before or after the STM32
chip in the chain. For example:
• OpenOCD TDI(output) -> STM32 TDI Pin (BS Input)
• STM32 BS TDO (output) -> STM32 Cortex-M3 TDI (input)
• STM32 Cortex-M3 TDO (output) -> SM32 TDO Pin
• STM32 TDO Pin (output) -> Xilinx TDI Pin (input)
• Xilinx TDO Pin -> OpenOCD TDO (input)
The “jtag device” commands would thus be in the order shown below. Note:
• jtag newtap Xilinx tap -irlen ...
• jtag newtap stm32 cpu -irlen ...
• jtag newtap stm32 bs -irlen ...
• # Create the debug target and say where it is
• target create stm32.cpu -chain-position stm32.cpu ...
15. SYSCOMP Sometimes my debugging session terminates with an error. When I
look into the log file, I can see these error messages: Error: arm7 9 common.c:561
arm7 9 execute sys speed(): timeout waiting for SYSCOMP
TODO.
Chapter 23: Tcl Crash Course
125
23 Tcl Crash Course
Not everyone knows Tcl - this is not intended to be a replacement for learning Tcl, the
intent of this chapter is to give you some idea of how the Tcl scripts work.
This chapter is written with two audiences in mind. (1) OpenOCD users who need to
understand a bit more of how Jim-Tcl works so they can do something useful, and (2) those
that want to add a new command to OpenOCD.
23.1 Tcl Rule #1
There is a famous joke, it goes like this:
1. Rule #1: The wife is always correct
2. Rule #2: If you think otherwise, See Rule #1
The Tcl equal is this:
1. Rule #1: Everything is a string
2. Rule #2: If you think otherwise, See Rule #1
As in the famous joke, the consequences of Rule #1 are profound. Once you understand
Rule #1, you will understand Tcl.
23.2 Tcl Rule #1b
There is a second pair of rules.
1. Rule #1: Control flow does not exist. Only commands
For example: the classic FOR loop or IF statement is not a control flow item, they are
commands, there is no such thing as control flow in Tcl.
2. Rule #2: If you think otherwise, See Rule #1
Actually what happens is this: There are commands that by convention, act like control
flow key words in other languages. One of those commands is the word “for”, another
command is “if”.
23.3 Per Rule #1 - All Results are strings
Every Tcl command results in a string. The word “result” is used deliberatly. No result is
just an empty string. Remember: Rule #1 - Everything is a string
23.4 Tcl Quoting Operators
In life of a Tcl script, there are two important periods of time, the difference is subtle.
1. Parse Time
2. Evaluation Time
The two key items here are how “quoted things” work in Tcl. Tcl has three primary quoting
constructs, the [square-brackets] the {curly-braces} and “double-quotes”
By now you should know $VARIABLES always start with a $DOLLAR sign. BTW: To set
a variable, you actually use the command “set”, as in “set VARNAME VALUE” much like
the ancient BASIC langauge “let x = 1” statement, but without the equal sign.
Chapter 23: Tcl Crash Course
126
• [square-brackets]
[square-brackets] are command substitutions. It operates much like Unix Shell ‘backticks‘. The result of a [square-bracket] operation is exactly 1 string. Remember Rule
#1 - Everything is a string. These two statements are roughly identical:
# bash example
X=‘date‘
echo "The Date is: $X"
# Tcl example
set X [date]
puts "The Date is: $X"
• “double-quoted-things”
“double-quoted-things” are just simply quoted text. $VARIABLES and [squarebrackets] are expanded in place - the result however is exactly 1 string. Remember
Rule #1 - Everything is a string
set x "Dinner"
puts "It is now \"[date]\", $x is in 1 hour"
• {Curly-Braces}
{Curly-Braces} are magic: $VARIABLES and [square-brackets] are parsed, but are
NOT expanded or executed. {Curly-Braces} are like ’single-quote’ operators in BASH
shell scripts, with the added feature: {curly-braces} can be nested, single quotes can
not. {{{this is nested 3 times}}} NOTE: [date] is a bad example; at this writing,
Jim/OpenOCD does not have a date command.
23.5 Consequences of Rule 1/2/3/4
The consequences of Rule 1 are profound.
23.5.1 Tokenisation & Execution.
Of course, whitespace, blank lines and #comment lines are handled in the normal way.
As a script is parsed, each (multi) line in the script file is tokenised and according to the
quoting rules. After tokenisation, that line is immedatly executed.
Multi line statements end with one or more “still-open” {curly-braces} which - eventually
- closes a few lines later.
23.5.2 Command Execution
Remember earlier: There are no “control flow” statements in Tcl. Instead there are COMMANDS that simply act like control flow operators.
Commands are executed like this:
1. Parse the next line into (argc) and (argv[]).
2. Look up (argv[0]) in a table and call its function.
3. Repeat until End Of File.
It sort of works like this:
for(;;){
ReadAndParse( &argc, &argv );
Chapter 23: Tcl Crash Course
127
cmdPtr = LookupCommand( argv[0] );
(*cmdPtr->Execute)( argc, argv );
}
When the command “proc” is parsed (which creates a procedure function) it gets 3 parameters on the command line. 1 the name of the proc (function), 2 the list of parameters, and 3
the body of the function. Not the choice of words: LIST and BODY. The PROC command
stores these items in a table somewhere so it can be found by “LookupCommand()”
23.5.3 The FOR command
The most interesting command to look at is the FOR command. In Tcl, the FOR command
is normally implemented in C. Remember, FOR is a command just like any other command.
When the ascii text containing the FOR command is parsed, the parser produces 5 parameter strings, (If in doubt: Refer to Rule #1) they are:
0. The ascii text ’for’
1. The start text
2. The test expression
3. The next text
4. The body text
Sort of reminds you of “main( int argc, char **argv )” does it not? Remember Rule #1
- Everything is a string. The key point is this: Often many of those parameters are in
{curly-braces} - thus the variables inside are not expanded or replaced until later.
Remember that every Tcl command looks like the classic “main( argc, argv )” function in
C. In JimTCL - they actually look like this:
int
MyCommand( Jim_Interp *interp,
int *argc,
Jim_Obj * const *argvs );
Real Tcl is nearly identical. Although the newer versions have introduced a byte-code parser
and intepreter, but at the core, it still operates in the same basic way.
23.5.4 FOR command implementation
To understand Tcl it is perhaps most helpful to see the FOR command. Remember, it is a
COMMAND not a control flow structure.
In Tcl there are two underlying C helper functions.
Remember Rule #1 - You are a string.
The first helper parses and executes commands found in an ascii string. Commands can
be seperated by semicolons, or newlines. While parsing, variables are expanded via the
quoting rules.
The second helper evaluates an ascii string as a numerical expression and returns a value.
Here is an example of how the FOR command could be implemented. The pseudo code
below does not show error handling.
Chapter 23: Tcl Crash Course
128
void Execute_AsciiString( void *interp, const char *string );
int Evaluate_AsciiExpression( void *interp, const char *string );
int
MyForCommand( void *interp,
int argc,
char **argv )
{
if( argc != 5 ){
SetResult( interp, "WRONG number of parameters");
return ERROR;
}
// argv[0] = the ascii string just like C
// Execute the start statement.
Execute_AsciiString( interp, argv[1] );
// Top of loop test
for(;;){
i = Evaluate_AsciiExpression(interp, argv[2]);
if( i == 0 )
break;
// Execute the body
Execute_AsciiString( interp, argv[3] );
// Execute the LOOP part
Execute_AsciiString( interp, argv[4] );
}
// Return no error
SetResult( interp, "" );
return SUCCESS;
}
Every other command IF, WHILE, FORMAT, PUTS, EXPR, everything works in the same
basic way.
23.6 OpenOCD Tcl Usage
23.6.1 source and find commands
Where: In many configuration files
Example: source [find FILENAME]
Remember the parsing rules
1. The find command is in square brackets, and is executed with the parameter FILE-
Chapter 23: Tcl Crash Course
129
NAME. It should find and return the full path to a file with that name; it uses an
internal search path. The RESULT is a string, which is substituted into the command
line in place of the bracketed find command. (Don’t try to use a FILENAME which
includes the "#" character. That character begins Tcl comments.)
2. The source command is executed with the resulting filename; it reads a file and executes as a script.
23.6.2 format command
Where: Generally occurs in numerous places.
Tcl has no command like printf(), instead it has format, which is really more like sprintf().
Example
set x 6
set y 7
puts [format "The answer: %d" [expr $x * $y]]
1. The SET command creates 2 variables, X and Y.
2. The double [nested] EXPR command performs math
The EXPR command produces numerical result as a string.
Refer to Rule #1
3. The format command is executed, producing a single string
Refer to Rule #1.
4. The PUTS command outputs the text.
23.6.3 Body or Inlined Text
Where: Various TARGET scripts.
#1 Good
proc someproc {} {
... multiple lines of stuff ...
}
$_TARGETNAME configure -event FOO someproc
#2 Good - no variables
$_TARGETNAME confgure -event foo "this ; that;"
#3 Good Curly Braces
$_TARGETNAME configure -event FOO {
puts "Time: [date]"
}
#4 DANGER DANGER DANGER
$_TARGETNAME configure -event foo "puts \"Time: [date]\""
1. The $ TARGETNAME is an OpenOCD variable convention.
$ TARGETNAME represents the last target created, the value changes each time a
new target is created. Remember the parsing rules. When the ascii text is parsed, the
$ TARGETNAME becomes a simple string, the name of the target which happens to
be a TARGET (object) command.
2. The 2nd parameter to the ‘-event’ parameter is a TCBODY
There are 4 examples:
Chapter 23: Tcl Crash Course
1.
2.
3.
4.
The
The
The
The
TCLBODY
TCLBODY
TCLBODY
TCLBODY
is
is
is
is
130
a simple string that happens to be a proc name
several simple commands seperated by semicolons
a multi-line {curly-brace} quoted string
a string with variables that get expanded.
In the end, when the target event FOO occurs the TCLBODY is evaluated. Method
#1 and #2 are functionally identical. For Method #3 and #4 it is more interesting.
What is the TCLBODY?
Remember the parsing rules. In case #3, {curly-braces} mean the $VARS and [squarebrackets] are expanded later, when the EVENT occurs, and the text is evaluated. In
case #4, they are replaced before the “Target Object Command” is executed. This
occurs at the same time $ TARGETNAME is replaced. In case #4 the date will never
change. {BTW: [date] is a bad example; at this writing, Jim/OpenOCD does not have
a date command}
23.6.4 Global Variables
Where: You might discover this when writing your own procs
In simple terms: Inside a PROC, if you need to access a global variable you must say so.
See also “upvar”. Example:
proc myproc { } {
set y 0 #Local variable Y
global x #Global variable X
puts [format "X=%d, Y=%d" $x $y]
}
23.7 Other Tcl Hacks
Dynamic variable creation
# Dynamically create a bunch of variables.
for { set x 0 } { $x < 32 } { set x [expr $x + 1]} {
# Create var name
set vn [format "BIT%d" $x]
# Make it a global
global $vn
# Set it.
set $vn
[expr (1 << $x)]
}
Dynamic proc/command creation
# One "X" function - 5 uart functions.
foreach who {A B C D E}
proc [format "show_uart%c" $who] { } "show_UARTx $who"
}
Appendix A: The GNU Free Documentation License.
131
Appendix A The GNU Free Documentation
License.
Version 1.2, November 2002
c
Copyright 2000,2001,2002 Free Software Foundation, Inc.
51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
0. PREAMBLE
The purpose of this License is to make a manual, textbook, or other functional and
useful document free in the sense of freedom: to assure everyone the effective freedom
to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way
to get credit for their work, while not being considered responsible for modifications
made by others.
This License is a kind of “copyleft”, which means that derivative works of the document
must themselves be free in the same sense. It complements the GNU General Public
License, which is a copyleft license designed for free software.
We have designed this License in order to use it for manuals for free software, because
free software needs free documentation: a free program should come with manuals
providing the same freedoms that the software does. But this License is not limited to
software manuals; it can be used for any textual work, regardless of subject matter or
whether it is published as a printed book. We recommend this License principally for
works whose purpose is instruction or reference.
1. APPLICABILITY AND DEFINITIONS
This License applies to any manual or other work, in any medium, that contains a
notice placed by the copyright holder saying it can be distributed under the terms
of this License. Such a notice grants a world-wide, royalty-free license, unlimited in
duration, to use that work under the conditions stated herein. The “Document”,
below, refers to any such manual or work. Any member of the public is a licensee, and
is addressed as “you”. You accept the license if you copy, modify or distribute the work
in a way requiring permission under copyright law.
A “Modified Version” of the Document means any work containing the Document or
a portion of it, either copied verbatim, or with modifications and/or translated into
another language.
A “Secondary Section” is a named appendix or a front-matter section of the Document
that deals exclusively with the relationship of the publishers or authors of the Document
to the Document’s overall subject (or to related matters) and contains nothing that
could fall directly within that overall subject. (Thus, if the Document is in part a
textbook of mathematics, a Secondary Section may not explain any mathematics.) The
relationship could be a matter of historical connection with the subject or with related
matters, or of legal, commercial, philosophical, ethical or political position regarding
them.
The “Invariant Sections” are certain Secondary Sections whose titles are designated, as
being those of Invariant Sections, in the notice that says that the Document is released
Appendix A: The GNU Free Documentation License.
132
under this License. If a section does not fit the above definition of Secondary then it is
not allowed to be designated as Invariant. The Document may contain zero Invariant
Sections. If the Document does not identify any Invariant Sections then there are none.
The “Cover Texts” are certain short passages of text that are listed, as Front-Cover
Texts or Back-Cover Texts, in the notice that says that the Document is released under
this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may
be at most 25 words.
A “Transparent” copy of the Document means a machine-readable copy, represented
in a format whose specification is available to the general public, that is suitable for
revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing
editor, and that is suitable for input to text formatters or for automatic translation to
a variety of formats suitable for input to text formatters. A copy made in an otherwise
Transparent file format whose markup, or absence of markup, has been arranged to
thwart or discourage subsequent modification by readers is not Transparent. An image
format is not Transparent if used for any substantial amount of text. A copy that is
not “Transparent” is called “Opaque”.
Examples of suitable formats for Transparent copies include plain ascii without
markup, Texinfo input format, LaTEX input format, SGML or XML using a publicly
available DTD, and standard-conforming simple HTML, PostScript or PDF designed
for human modification. Examples of transparent image formats include PNG, XCF
and JPG. Opaque formats include proprietary formats that can be read and edited
only by proprietary word processors, SGML or XML for which the DTD and/or
processing tools are not generally available, and the machine-generated HTML,
PostScript or PDF produced by some word processors for output purposes only.
The “Title Page” means, for a printed book, the title page itself, plus such following
pages as are needed to hold, legibly, the material this License requires to appear in the
title page. For works in formats which do not have any title page as such, “Title Page”
means the text near the most prominent appearance of the work’s title, preceding the
beginning of the body of the text.
A section “Entitled XYZ” means a named subunit of the Document whose title either
is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in
another language. (Here XYZ stands for a specific section name mentioned below, such
as “Acknowledgements”, “Dedications”, “Endorsements”, or “History”.) To “Preserve
the Title” of such a section when you modify the Document means that it remains a
section “Entitled XYZ” according to this definition.
The Document may include Warranty Disclaimers next to the notice which states that
this License applies to the Document. These Warranty Disclaimers are considered to
be included by reference in this License, but only as regards disclaiming warranties:
any other implication that these Warranty Disclaimers may have is void and has no
effect on the meaning of this License.
2. VERBATIM COPYING
You may copy and distribute the Document in any medium, either commercially or
noncommercially, provided that this License, the copyright notices, and the license
notice saying this License applies to the Document are reproduced in all copies, and
Appendix A: The GNU Free Documentation License.
133
that you add no other conditions whatsoever to those of this License. You may not use
technical measures to obstruct or control the reading or further copying of the copies
you make or distribute. However, you may accept compensation in exchange for copies.
If you distribute a large enough number of copies you must also follow the conditions
in section 3.
You may also lend copies, under the same conditions stated above, and you may publicly
display copies.
3. COPYING IN QUANTITY
If you publish printed copies (or copies in media that commonly have printed covers) of
the Document, numbering more than 100, and the Document’s license notice requires
Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all
these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on
the back cover. Both covers must also clearly and legibly identify you as the publisher
of these copies. The front cover must present the full title with all words of the title
equally prominent and visible. You may add other material on the covers in addition.
Copying with changes limited to the covers, as long as they preserve the title of the
Document and satisfy these conditions, can be treated as verbatim copying in other
respects.
If the required texts for either cover are too voluminous to fit legibly, you should put
the first ones listed (as many as fit reasonably) on the actual cover, and continue the
rest onto adjacent pages.
If you publish or distribute Opaque copies of the Document numbering more than 100,
you must either include a machine-readable Transparent copy along with each Opaque
copy, or state in or with each Opaque copy a computer-network location from which
the general network-using public has access to download using public-standard network
protocols a complete Transparent copy of the Document, free of added material. If
you use the latter option, you must take reasonably prudent steps, when you begin
distribution of Opaque copies in quantity, to ensure that this Transparent copy will
remain thus accessible at the stated location until at least one year after the last time
you distribute an Opaque copy (directly or through your agents or retailers) of that
edition to the public.
It is requested, but not required, that you contact the authors of the Document well
before redistributing any large number of copies, to give them a chance to provide you
with an updated version of the Document.
4. MODIFICATIONS
You may copy and distribute a Modified Version of the Document under the conditions
of sections 2 and 3 above, provided that you release the Modified Version under precisely
this License, with the Modified Version filling the role of the Document, thus licensing
distribution and modification of the Modified Version to whoever possesses a copy of
it. In addition, you must do these things in the Modified Version:
A. Use in the Title Page (and on the covers, if any) a title distinct from that of the
Document, and from those of previous versions (which should, if there were any,
be listed in the History section of the Document). You may use the same title as
a previous version if the original publisher of that version gives permission.
Appendix A: The GNU Free Documentation License.
134
B. List on the Title Page, as authors, one or more persons or entities responsible for
authorship of the modifications in the Modified Version, together with at least five
of the principal authors of the Document (all of its principal authors, if it has fewer
than five), unless they release you from this requirement.
C. State on the Title page the name of the publisher of the Modified Version, as the
publisher.
D. Preserve all the copyright notices of the Document.
E. Add an appropriate copyright notice for your modifications adjacent to the other
copyright notices.
F. Include, immediately after the copyright notices, a license notice giving the public
permission to use the Modified Version under the terms of this License, in the form
shown in the Addendum below.
G. Preserve in that license notice the full lists of Invariant Sections and required Cover
Texts given in the Document’s license notice.
H. Include an unaltered copy of this License.
I. Preserve the section Entitled “History”, Preserve its Title, and add to it an item
stating at least the title, year, new authors, and publisher of the Modified Version
as given on the Title Page. If there is no section Entitled “History” in the Document, create one stating the title, year, authors, and publisher of the Document
as given on its Title Page, then add an item describing the Modified Version as
stated in the previous sentence.
J. Preserve the network location, if any, given in the Document for public access to
a Transparent copy of the Document, and likewise the network locations given in
the Document for previous versions it was based on. These may be placed in the
“History” section. You may omit a network location for a work that was published
at least four years before the Document itself, or if the original publisher of the
version it refers to gives permission.
K. For any section Entitled “Acknowledgements” or “Dedications”, Preserve the Title
of the section, and preserve in the section all the substance and tone of each of the
contributor acknowledgements and/or dedications given therein.
L. Preserve all the Invariant Sections of the Document, unaltered in their text and
in their titles. Section numbers or the equivalent are not considered part of the
section titles.
M. Delete any section Entitled “Endorsements”. Such a section may not be included
in the Modified Version.
N. Do not retitle any existing section to be Entitled “Endorsements” or to conflict in
title with any Invariant Section.
O. Preserve any Warranty Disclaimers.
If the Modified Version includes new front-matter sections or appendices that qualify
as Secondary Sections and contain no material copied from the Document, you may at
your option designate some or all of these sections as invariant. To do this, add their
titles to the list of Invariant Sections in the Modified Version’s license notice. These
titles must be distinct from any other section titles.
Appendix A: The GNU Free Documentation License.
135
You may add a section Entitled “Endorsements”, provided it contains nothing but
endorsements of your Modified Version by various parties—for example, statements of
peer review or that the text has been approved by an organization as the authoritative
definition of a standard.
You may add a passage of up to five words as a Front-Cover Text, and a passage of up
to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified
Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be
added by (or through arrangements made by) any one entity. If the Document already
includes a cover text for the same cover, previously added by you or by arrangement
made by the same entity you are acting on behalf of, you may not add another; but
you may replace the old one, on explicit permission from the previous publisher that
added the old one.
The author(s) and publisher(s) of the Document do not by this License give permission
to use their names for publicity for or to assert or imply endorsement of any Modified
Version.
5. COMBINING DOCUMENTS
You may combine the Document with other documents released under this License,
under the terms defined in section 4 above for modified versions, provided that you
include in the combination all of the Invariant Sections of all of the original documents,
unmodified, and list them all as Invariant Sections of your combined work in its license
notice, and that you preserve all their Warranty Disclaimers.
The combined work need only contain one copy of this License, and multiple identical
Invariant Sections may be replaced with a single copy. If there are multiple Invariant
Sections with the same name but different contents, make the title of each such section
unique by adding at the end of it, in parentheses, the name of the original author or
publisher of that section if known, or else a unique number. Make the same adjustment
to the section titles in the list of Invariant Sections in the license notice of the combined
work.
In the combination, you must combine any sections Entitled “History” in the various original documents, forming one section Entitled “History”; likewise combine any
sections Entitled “Acknowledgements”, and any sections Entitled “Dedications”. You
must delete all sections Entitled “Endorsements.”
6. COLLECTIONS OF DOCUMENTS
You may make a collection consisting of the Document and other documents released
under this License, and replace the individual copies of this License in the various
documents with a single copy that is included in the collection, provided that you
follow the rules of this License for verbatim copying of each of the documents in all
other respects.
You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted
document, and follow this License in all other respects regarding verbatim copying of
that document.
7. AGGREGATION WITH INDEPENDENT WORKS
A compilation of the Document or its derivatives with other separate and independent
documents or works, in or on a volume of a storage or distribution medium, is called
Appendix A: The GNU Free Documentation License.
136
an “aggregate” if the copyright resulting from the compilation is not used to limit the
legal rights of the compilation’s users beyond what the individual works permit. When
the Document is included in an aggregate, this License does not apply to the other
works in the aggregate which are not themselves derivative works of the Document.
If the Cover Text requirement of section 3 is applicable to these copies of the Document,
then if the Document is less than one half of the entire aggregate, the Document’s Cover
Texts may be placed on covers that bracket the Document within the aggregate, or the
electronic equivalent of covers if the Document is in electronic form. Otherwise they
must appear on printed covers that bracket the whole aggregate.
8. TRANSLATION
Translation is considered a kind of modification, so you may distribute translations
of the Document under the terms of section 4. Replacing Invariant Sections with
translations requires special permission from their copyright holders, but you may
include translations of some or all Invariant Sections in addition to the original versions
of these Invariant Sections. You may include a translation of this License, and all the
license notices in the Document, and any Warranty Disclaimers, provided that you
also include the original English version of this License and the original versions of
those notices and disclaimers. In case of a disagreement between the translation and
the original version of this License or a notice or disclaimer, the original version will
prevail.
If a section in the Document is Entitled “Acknowledgements”, “Dedications”, or “History”, the requirement (section 4) to Preserve its Title (section 1) will typically require
changing the actual title.
9. TERMINATION
You may not copy, modify, sublicense, or distribute the Document except as expressly
provided for under this License. Any other attempt to copy, modify, sublicense or
distribute the Document is void, and will automatically terminate your rights under
this License. However, parties who have received copies, or rights, from you under this
License will not have their licenses terminated so long as such parties remain in full
compliance.
10. FUTURE REVISIONS OF THIS LICENSE
The Free Software Foundation may publish new, revised versions of the GNU Free
Documentation License from time to time. Such new versions will be similar in spirit
to the present version, but may differ in detail to address new problems or concerns.
See http://www.gnu.org/copyleft/.
Each version of the License is given a distinguishing version number. If the Document
specifies that a particular numbered version of this License “or any later version”
applies to it, you have the option of following the terms and conditions either of that
specified version or of any later version that has been published (not as a draft) by
the Free Software Foundation. If the Document does not specify a version number of
this License, you may choose any version ever published (not as a draft) by the Free
Software Foundation.
Appendix A: The GNU Free Documentation License.
137
ADDENDUM: How to use this License for your documents
To use this License in a document you have written, include a copy of the License in the
document and put the following copyright and license notices just after the title page:
Copyright (C) year your name.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.2
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
Texts. A copy of the license is included in the section entitled ‘‘GNU
Free Documentation License’’.
If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the
“with. . . Texts.” line with this:
with the Invariant Sections being list their titles, with
the Front-Cover Texts being list, and with the Back-Cover Texts
being list.
If you have Invariant Sections without Cover Texts, or some other combination of the three,
merge those two alternatives to suit the situation.
If your document contains nontrivial examples of program code, we recommend releasing
these examples in parallel under your choice of free software license, such as the GNU
General Public License, to permit their use in free software.
OpenOCD Concept Index
138
OpenOCD Concept Index
A
about . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
adaptive clocking . . . . . . . . . . . . . . . . . . . . . . . . . 47, 120
Architecture Specific Commands . . . . . . . . . . . . . . . 96
ARM. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
ARM semihosting . . . . . . . . . . . . . . . . . . . . . . . . . 17, 100
ARM11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
ARM7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
ARM720T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
ARM9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
ARM920T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
ARM926ej-s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
ARM966E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
ARMv4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
ARMv5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
ARMv6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
ARMv7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
at91sam3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
at91sam4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
autoprobe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
dotted name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
E
ETB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ETM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
event, reset-init . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51, 56,
96
96
26
65
F
faq . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
flash configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
flash erasing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
flash programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
flash protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
flash reading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
flash writing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
FPGA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
FTDI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
B
G
board config file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
breakpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
GDB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35, 114
GDB configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
GDB server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
GDB target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
C
CFI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
command line options . . . . . . . . . . . . . . . . . . . . . . . . . 11
commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Common Flash Interface . . . . . . . . . . . . . . . . . . . . . . . 71
config command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
config file, board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
config file, interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
config file, overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
config file, target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
config file, user . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
configuration stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Connecting to GDB . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Core Specific Commands . . . . . . . . . . . . . . . . . . . . . . 96
Cortex-M3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
CPU type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
CPU variant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
D
DAP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
DCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101, 107
Debug Access Port . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
developers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
directory search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
disassemble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
dongles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
H
halt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
I
image dumping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
image loading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
init board procedure. . . . . . . . . . . . . . . . . . . . . . . . . . .
init targets procedure . . . . . . . . . . . . . . . . . . . . . . . . .
initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
interface config file. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
94
94
27
31
34
38
J
Jim-Tcl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
jrc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
JTAG. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1, 46
JTAG autoprobe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
JTAG Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
JTAG Route Controller . . . . . . . . . . . . . . . . . . . . . . . . 57
L
libdcc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Linux-ARM DCC support . . . . . . . . . . . . . . . . . . . . 107
OpenOCD Concept Index
139
logfile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
M
memory access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
message level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mFlash commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mFlash Configuration . . . . . . . . . . . . . . . . . . . . . . . . . .
93
90
81
80
N
NAND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
NAND configuration . . . . . . . . . . . . . . . . . . . . . . . . . . .
NAND erasing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
NAND other commands . . . . . . . . . . . . . . . . . . . . . . .
NAND programming . . . . . . . . . . . . . . . . . . . . . . . 84,
NAND reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
NAND verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
NAND writing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
82
82
84
85
85
83
85
84
O
object command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
P
str9xpec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
SVF. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
SWD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
T
TAP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
TAP configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
TAP declaration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
TAP events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
TAP naming convention . . . . . . . . . . . . . . . . . . . . . . . 54
TAP state names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
target config file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
target events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
target initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
target type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
target, current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
target, list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
tcl. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Tcl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Tcl Scripting API . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Tcl scripts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
TCP port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
TFTP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
tracing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96, 107
translation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Transport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
PLD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
printer port. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
profiling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Programming using GDB . . . . . . . . . . . . . . . . . . . . . 115
U
R
V
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Reset Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
reset-init handler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
RTCK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5, 47, 120
variable names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
vector catch . . . . . . . . . . . . . . . . 16, 101, 105, 106, 107
vector table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
S
scan chain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Serial Peripheral Interface . . . . . . . . . . . . . . . . . . . . . 46
Serial Vector Format . . . . . . . . . . . . . . . . . . . . . . . . . 112
Serial Wire Debug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
SMI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
SMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29, 116
SPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
STMicroelectronics Serial Memory Interface . . . . 71
stmsmi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
USB Adapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
user config file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
W
watchpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
wiggler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
X
Xilinx Serial Vector Format . . . . . . . . . . . . . . . . . . . 112
XScale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
XSVF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Z
zy1000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Command and Driver Index
140
Command and Driver Index
$
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
$target_name
arp_examine . . . . . . . . . . . . . . . . . . . .
arp_halt . . . . . . . . . . . . . . . . . . . . . . .
arp_poll . . . . . . . . . . . . . . . . . . . . . . .
arp_reset . . . . . . . . . . . . . . . . . . . . . .
arp_waitstate . . . . . . . . . . . . . . . . . .
array2mem . . . . . . . . . . . . . . . . . . . . . .
cget . . . . . . . . . . . . . . . . . . . . . . . . . . . .
configure . . . . . . . . . . . . . . . . . . . . . .
curstate . . . . . . . . . . . . . . . . . . . . . . .
eventlist . . . . . . . . . . . . . . . . . . . . . .
invoke-event . . . . . . . . . . . . . . . . . . .
mdb . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mdh . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mdw . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mem2array . . . . . . . . . . . . . . . . . . . . . .
mwb . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mwh . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mww . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
63
63
63
63
63
63
64
62
64
64
64
64
64
64
63
64
64
64
at91rm9200. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam3 gpnvm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam3 gpnvm clear . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam3 gpnvm set . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam3 gpnvm show . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam3 info. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam3 slowclk . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam7 gpnvm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam9 ale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam9 ce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam9 cle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
at91sam9 rdy_busy . . . . . . . . . . . . . . . . . . . . . . . . . . . .
avr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
39
72
72
72
72
73
73
73
73
73
74
86
86
86
86
86
74
B
bp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
A
adapter_khz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
adapter_name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
adapter_nsrst_assert_width . . . . . . . . . . . . . . . . . 49
adapter_nsrst_delay . . . . . . . . . . . . . . . . . . . . . . . . . 49
add_script_search_dir . . . . . . . . . . . . . . . . . . . . . . . 91
aduc702x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
amt_jtagaccel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
append_file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
arm core_state . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
arm disassemble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
arm mcr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
arm mrc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
arm reg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
arm semihosting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
arm-jtag-ew . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
arm11 memwrite burst . . . . . . . . . . . . . . . . . . . . . . . . 105
arm11 memwrite error_fatal . . . . . . . . . . . . . . . . . 105
arm11 step_irq_enable . . . . . . . . . . . . . . . . . . . . . . 105
arm11 vcr . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
arm7_9 dbgrq. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
arm7_9 dcc_downloads . . . . . . . . . . . . . . . . . . . . . . . 101
arm7_9 fast_memory_access . . . . . . . . . . . . . . . . . . 101
arm720t cp15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
arm9 vector_catch . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
arm920t cache_info . . . . . . . . . . . . . . . . . . . . . . . . . . 102
arm920t cp15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
arm920t cp15i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
arm920t read_cache . . . . . . . . . . . . . . . . . . . . . . . . . . 102
arm920t read_mmu . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
arm926ejs cache_info . . . . . . . . . . . . . . . . . . . . . . . 102
arm966e cp15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
armjtagew_info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
C
cat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
cfi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
cortex_m3 maskisr . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
cortex_m3 reset_config . . . . . . . . . . . . . . . . . . . . . 107
cortex_m3 vector_catch . . . . . . . . . . . . . . . . . . . . . 107
cp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
D
dap apid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
dap apsel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
dap baseaddr. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
dap info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
dap memaccess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
davinci . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
debug_level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
drscan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
dummy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39, 99
dump_image. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
E
echo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ep93xx . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etb config . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etb trigger_percent . . . . . . . . . . . . . . . . . . . . . . . . . .
etm analyze . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etm config . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etm dump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
91
39
99
99
99
98
96
98
Command and Driver Index
etm image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etm info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etm load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etm start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etm status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etm stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etm tracemode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etm trigger_debug . . . . . . . . . . . . . . . . . . . . . . . . . . . .
etm_dummy config . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
141
98
97
98
98
97
98
97
97
99
90
F
fast_load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
fast_load_image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
flash bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
flash banks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
flash erase_address . . . . . . . . . . . . . . . . . . . . . . . . . . 70
flash erase_check . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
flash erase_sector . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
flash fillb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
flash fillh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
flash fillw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
flash info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
flash list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
flash probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
flash protect. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
flash write_bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
flash write_image . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
flush_count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
fm3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
ft2232 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
ft2232_device_desc . . . . . . . . . . . . . . . . . . . . . . . . . . 39
ft2232_latency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
ft2232_layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
ft2232_serial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
ft2232_vid_pid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
G
gdb_breakpoint_override . . . . . . . . . . . . . . . . . . . . .
gdb_flash_program. . . . . . . . . . . . . . . . . . . . . . . . . . . .
gdb_memory_map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
gdb_port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
gdb_report_data_abort . . . . . . . . . . . . . . . . . . . . . . .
gw16012 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
36
36
36
35
36
42
H
halt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
J
jlink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
jlink caps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
jlink config . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
jlink config ip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
jlink config kickstart. . . . . . . . . . . . . . . . . . . . . . . 42
jlink config mac_address . . . . . . . . . . . . . . . . . . . . 42
jlink config reset . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
jlink config save . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
jlink config usb_address . . . . . . . . . . . . . . . . . . . . 43
jlink hw_jtag. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
jlink info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
jlink pid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
jtag arp_init. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
jtag arp_init-reset . . . . . . . . . . . . . . . . . . . . . . . . . . 52
jtag cget . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
jtag configure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
jtag names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
jtag newtap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
jtag tapdisable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
jtag tapenable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
jtag tapisenabled . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
jtag_init . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
jtag_ntrst_assert_width . . . . . . . . . . . . . . . . . . . . . 50
jtag_ntrst_delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
jtag_rclk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
jtag_reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
L
load_image. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
log_output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
lpc2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
lpc2000 part_id . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
lpc288x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
lpc2900 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
lpc2900 password . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
lpc2900 read_custom . . . . . . . . . . . . . . . . . . . . . . . . . .
lpc2900 secure_jtag . . . . . . . . . . . . . . . . . . . . . . . . . .
lpc2900 secure_sector . . . . . . . . . . . . . . . . . . . . . . .
lpc2900 signature . . . . . . . . . . . . . . . . . . . . . . . . . . . .
lpc2900 write_custom . . . . . . . . . . . . . . . . . . . . . . . .
lpc3180 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
lpc3180 select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
94
91
74
74
74
74
75
75
76
76
75
76
87
87
93
M
I
init . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
init_reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
interface transports . . . . . . . . . . . . . . . . . . . . . . . .
interface_list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
ip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
irscan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
34
51
38
38
mac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mdb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mdh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mdw . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
meminfo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
93
93
93
93
93
Command and Driver Index
mflash bank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mflash config boot . . . . . . . . . . . . . . . . . . . . . . . . . . .
mflash config pll . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mflash config storage . . . . . . . . . . . . . . . . . . . . . . . .
mflash dump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mflash probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mflash write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mwb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mwh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mww . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mx3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mxc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
mxc biswap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
142
80
81
81
81
81
81
81
94
94
94
87
87
87
N
check_bad_blocks . . . . . . . . . . . . . . . . . . . . . . .
device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
dump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
erase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
info . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
raw_access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
verify . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
85
83
83
84
85
83
83
86
85
84
ocl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
oocd_trace. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
oocd_trace config . . . . . . . . . . . . . . . . . . . . . . . . . . . .
oocd_trace resync . . . . . . . . . . . . . . . . . . . . . . . . . . . .
oocd_trace status . . . . . . . . . . . . . . . . . . . . . . . . . . . .
opendous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
orion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
76
99
99
99
99
45
87
nand
nand
nand
nand
nand
nand
nand
nand
nand
nand
O
P
parport . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
parport_cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
parport_port . . . . . . . . . . . . . . . . . . . . . . . . . . 39, 42, 44
parport_toggling_time . . . . . . . . . . . . . . . . . . . . . . . 44
parport_write_on_exit . . . . . . . . . . . . . . . . . . . . . . . 44
pathmove . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
peek . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
pic32mx . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
pic32mx pgm_word . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
pic32mx unlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
pld device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
pld devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
pld load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
poke . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
poll . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
presto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
presto_serial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
R
rbp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
reg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
remote_bitbang . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
remote_bitbang_host . . . . . . . . . . . . . . . . . . . . . . . . . 41
remote_bitbang_port . . . . . . . . . . . . . . . . . . . . . . . . . 41
reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
reset halt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
reset init . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
reset run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
reset_config . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
resume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
rlink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
rm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
rtck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
runtest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
rwp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
S
s3c2410 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
s3c2412 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
s3c2440 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
s3c2443 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
s3c6400 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
scan_chain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
sleep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
soft_reset_halt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stellaris . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stellaris recover bank_id . . . . . . . . . . . . . . . . . . .
step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stlink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stlink_api. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stlink_device_desc . . . . . . . . . . . . . . . . . . . . . . . . . .
stlink_layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stlink_serial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stlink_vid_pid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stm32f1x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stm32f1x lock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stm32f1x options_read . . . . . . . . . . . . . . . . . . . . . . .
stm32f1x options_write . . . . . . . . . . . . . . . . . . . . . .
stm32f1x unlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stm32f2x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
stmsmi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
str7x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
str7x disable_jtag . . . . . . . . . . . . . . . . . . . . . . . . . . .
str9x . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
str9x flash_config . . . . . . . . . . . . . . . . . . . . . . . . . . .
str9xpec . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
str9xpec disable_turbo . . . . . . . . . . . . . . . . . . . . . .
str9xpec enable_turbo . . . . . . . . . . . . . . . . . . . . . . .
str9xpec lock. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
str9xpec options_cmap . . . . . . . . . . . . . . . . . . . . . . .
str9xpec options_lvdsel . . . . . . . . . . . . . . . . . . . . .
str9xpec options_lvdthd . . . . . . . . . . . . . . . . . . . . .
str9xpec options_lvdwarn . . . . . . . . . . . . . . . . . . . .
str9xpec options_read . . . . . . . . . . . . . . . . . . . . . . .
88
88
88
88
88
54
90
90
92
77
77
92
45
45
45
45
45
45
77
77
77
77
77
78
71
78
78
78
78
80
80
80
80
80
80
80
80
80
Command and Driver Index
143
str9xpec options_write . . . . . . . . . . . . . . . . . . . . . . 80
str9xpec part_id . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
str9xpec unlock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
svf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
swd newdap . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
swd wcr trn prescale . . . . . . . . . . . . . . . . . . . . . . . . . 46
T
target count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
target create. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
target current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
target names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
target number. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
target types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
target_request debugmsgs . . . . . . . . . . . . . . . . . . . 108
targets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
tcl_port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
telnet_port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
test_image. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
tms470 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
tms470 flash_keyset . . . . . . . . . . . . . . . . . . . . . . . . . . 78
tms470 osc_mhz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
tms470 plldis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
trace history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
trace point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
transport list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
transport select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
trunc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
U
ulink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
usb_blaster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41,
usb_blaster_device_desc . . . . . . . . . . . . . . . . . . . . .
usb_blaster_vid_pid . . . . . . . . . . . . . . . . . . . . . . . . .
usbprog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
45
42
41
41
45
V
verify_image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
verify_ircapture. . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
verify_jtag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
virt2phys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
virtex2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
virtex2 read_stat . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
virtual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78
vsllink . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
W
wait_halt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
wp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
X
xscale analyze_trace . . . . . . . . . . . . . . . . . . . . . . .
xscale cache_clean_address . . . . . . . . . . . . . . . .
xscale cache_info . . . . . . . . . . . . . . . . . . . . . . . . . . .
xscale cp15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xscale dcache . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xscale debug_handler . . . . . . . . . . . . . . . . . . . . . . .
xscale dump_trace . . . . . . . . . . . . . . . . . . . . . . . . . . .
xscale icache . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xscale mmu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
xscale trace_buffer . . . . . . . . . . . . . . . . . . . . . . . .
xscale trace_image . . . . . . . . . . . . . . . . . . . . . . . . . .
xscale vector_catch . . . . . . . . . . . . . . . . . . . . . . . .
xscale vector_table . . . . . . . . . . . . . . . . . . . . . . . .
xsvf . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
104
104
104
104
104
104
104
104
104
104
105
105
105
112
Z
ZY1000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement