1 \input texinfo @c -*-texinfo-*-
3 @setfilename openocd.info
4 @settitle OpenOCD User's Guide
5 @dircategory Development
7 * OpenOCD: (openocd). OpenOCD User's Guide
16 This User's Guide documents
17 release @value{VERSION},
18 dated @value{UPDATED},
19 of the Open On-Chip Debugger (OpenOCD).
22 @item Copyright @copyright{} 2008 The OpenOCD Project
23 @item Copyright @copyright{} 2007-2008 Spencer Oliver @email{spen@@spen-soft.co.uk}
24 @item Copyright @copyright{} 2008 Oyvind Harboe @email{oyvind.harboe@@zylin.com}
25 @item Copyright @copyright{} 2008 Duane Ellis @email{openocd@@duaneellis.com}
29 Permission is granted to copy, distribute and/or modify this document
30 under the terms of the GNU Free Documentation License, Version 1.2 or
31 any later version published by the Free Software Foundation; with no
32 Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
33 Texts. A copy of the license is included in the section entitled ``GNU
34 Free Documentation License''.
39 @titlefont{@emph{Open On-Chip Debugger:}}
41 @title OpenOCD User's Guide
42 @subtitle for release @value{VERSION}
43 @subtitle @value{UPDATED}
46 @vskip 0pt plus 1filll
55 @top OpenOCD User's Guide
61 * About:: About OpenOCD
62 * Developers:: OpenOCD Developers
63 * Building OpenOCD:: Building OpenOCD From SVN
64 * JTAG Hardware Dongles:: JTAG Hardware Dongles
65 * Running:: Running OpenOCD
66 * Simple Configuration Files:: Simple Configuration Files
67 * Config File Guidelines:: Config File Guidelines
68 * About JIM-Tcl:: About JIM-Tcl
69 * Daemon Configuration:: Daemon Configuration
70 * Interface - Dongle Configuration:: Interface - Dongle Configuration
71 * Reset Configuration:: Reset Configuration
72 * TAP Declaration:: TAP Declaration
73 * CPU Configuration:: CPU Configuration
74 * Flash Commands:: Flash Commands
75 * NAND Flash Commands:: NAND Flash Commands
76 * General Commands:: General Commands
77 * Architecture and Core Commands:: Architecture and Core Commands
78 * JTAG Commands:: JTAG Commands
79 * Sample Scripts:: Sample Target Scripts
81 * GDB and OpenOCD:: Using GDB and OpenOCD
82 * Tcl Scripting API:: Tcl Scripting API
83 * Upgrading:: Deprecated/Removed Commands
84 * Target Library:: Target Library
85 * FAQ:: Frequently Asked Questions
86 * Tcl Crash Course:: Tcl Crash Course
87 * License:: GNU Free Documentation License
89 @comment DO NOT use the plain word ``Index'', reason: CYGWIN filename
90 @comment case issue with ``Index.html'' and ``index.html''
91 @comment Occurs when creating ``--html --no-split'' output
92 @comment This fix is based on: http://sourceware.org/ml/binutils/2006-05/msg00215.html
93 * OpenOCD Concept Index:: Concept Index
94 * Command and Driver Index:: Command and Driver Index
101 OpenOCD was created by Dominic Rath as part of a diploma thesis written at the
102 University of Applied Sciences Augsburg (@uref{http://www.fh-augsburg.de}).
103 Since that time, the project has grown into an active open-source project,
104 supported by a diverse community of software and hardware developers from
107 @section What is OpenOCD?
109 The Open On-Chip Debugger (OpenOCD) aims to provide debugging,
110 in-system programming and boundary-scan testing for embedded target
113 @b{JTAG:} OpenOCD uses a ``hardware interface dongle'' to communicate
114 with the JTAG (IEEE 1149.1) compliant TAPs on your target board.
115 A @dfn{TAP} is a ``Test Access Port'', a module which processes
116 special instructions and data. TAPs are daisy-chained within and
117 between chips and boards.
119 @b{Dongles:} OpenOCD currently supports many types of hardware dongles: USB
120 based, parallel port based, and other standalone boxes that run
121 OpenOCD internally. @xref{JTAG Hardware Dongles}.
123 @b{GDB Debug:} It allows ARM7 (ARM7TDMI and ARM720t), ARM9 (ARM920T,
124 ARM922T, ARM926EJ--S, ARM966E--S), XScale (PXA25x, IXP42x) and
125 Cortex-M3 (Stellaris LM3 and ST STM32) based cores to be
126 debugged via the GDB protocol.
128 @b{Flash Programing:} Flash writing is supported for external CFI
129 compatible NOR flashes (Intel and AMD/Spansion command set) and several
130 internal flashes (LPC2000, AT91SAM7, STR7x, STR9x, LM3, and
131 STM32x). Preliminary support for various NAND flash controllers
132 (LPC3180, Orion, S3C24xx, more) controller is included.
134 @section OpenOCD Web Site
136 The OpenOCD web site provides the latest public news from the community:
138 @uref{http://openocd.berlios.de/web/}
140 @section Latest User's Guide:
142 The user's guide you are now reading may not be the latest one
143 available. A version for more recent code may be available.
144 Its HTML form is published irregularly at:
146 @uref{http://openocd.berlios.de/doc/html/index.html}
148 PDF form is likewise published at:
150 @uref{http://openocd.berlios.de/doc/pdf/openocd.pdf}
152 @section OpenOCD User's Forum
154 There is an OpenOCD forum (phpBB) hosted by SparkFun:
156 @uref{http://forum.sparkfun.com/viewforum.php?f=18}
160 @chapter OpenOCD Developer Resources
163 If you are interested in improving the state of OpenOCD's debugging and
164 testing support, new contributions will be welcome. Motivated developers
165 can produce new target, flash or interface drivers, improve the
166 documentation, as well as more conventional bug fixes and enhancements.
168 The resources in this chapter are available for developers wishing to explore
169 or expand the OpenOCD source code.
171 @section OpenOCD Subversion Repository
173 The ``Building From Source'' section provides instructions to retrieve
174 and and build the latest version of the OpenOCD source code.
175 @xref{Building OpenOCD}.
177 Developers that want to contribute patches to the OpenOCD system are
178 @b{strongly} encouraged to base their work off of the most recent trunk
179 revision. Patches created against older versions may require additional
180 work from their submitter in order to be updated for newer releases.
182 @section Doxygen Developer Manual
184 During the development of the 0.2.0 release, the OpenOCD project began
185 providing a Doxygen reference manual. This document contains more
186 technical information about the software internals, development
187 processes, and similar documentation:
189 @uref{http://openocd.berlios.de/doc/doxygen/index.html}
191 This document is a work-in-progress, but contributions would be welcome
192 to fill in the gaps. All of the source files are provided in-tree,
193 listed in the Doxyfile configuration in the top of the repository trunk.
195 @section OpenOCD Developer Mailing List
197 The OpenOCD Developer Mailing List provides the primary means of
198 communication between developers:
200 @uref{https://lists.berlios.de/mailman/listinfo/openocd-development}
202 All drivers developers are enouraged to also subscribe to the list of
203 SVN commits to keep pace with the ongoing changes:
205 @uref{https://lists.berlios.de/mailman/listinfo/openocd-svn}
208 @node Building OpenOCD
209 @chapter Building OpenOCD
212 @section Pre-Built Tools
213 If you are interested in getting actual work done rather than building
214 OpenOCD, then check if your interface supplier provides binaries for
215 you. Chances are that that binary is from some SVN version that is more
216 stable than SVN trunk where bleeding edge development takes place.
218 @section Packagers Please Read!
220 You are a @b{PACKAGER} of OpenOCD if you
223 @item @b{Sell dongles} and include pre-built binaries
224 @item @b{Supply tools} i.e.: A complete development solution
225 @item @b{Supply IDEs} like Eclipse, or RHIDE, etc.
226 @item @b{Build packages} i.e.: RPM files, or DEB files for a Linux Distro
229 As a @b{PACKAGER}, you will experience first reports of most issues.
230 When you fix those problems for your users, your solution may help
231 prevent hundreds (if not thousands) of other questions from other users.
233 If something does not work for you, please work to inform the OpenOCD
234 developers know how to improve the system or documentation to avoid
235 future problems, and follow-up to help us ensure the issue will be fully
236 resolved in our future releases.
238 That said, the OpenOCD developers would also like you to follow a few
242 @item @b{Always build with printer ports enabled.}
243 @item @b{Try to use LIBFTDI + LIBUSB where possible. You cover more bases.}
247 @item @b{Why YES to LIBFTDI + LIBUSB?}
249 @item @b{LESS} work - libusb perhaps already there
250 @item @b{LESS} work - identical code, multiple platforms
251 @item @b{MORE} dongles are supported
252 @item @b{MORE} platforms are supported
253 @item @b{MORE} complete solution
255 @item @b{Why not LIBFTDI + LIBUSB} (i.e.: ftd2xx instead)?
257 @item @b{LESS} speed - some say it is slower
258 @item @b{LESS} complex to distribute (external dependencies)
262 @section Building From Source
264 You can download the current SVN version with an SVN client of your choice from the
265 following repositories:
267 @uref{svn://svn.berlios.de/openocd/trunk}
271 @uref{http://svn.berlios.de/svnroot/repos/openocd/trunk}
273 Using the SVN command line client, you can use the following command to fetch the
274 latest version (make sure there is no (non-svn) directory called "openocd" in the
278 svn checkout svn://svn.berlios.de/openocd/trunk openocd
281 If you prefer GIT based tools, the @command{git-svn} package works too:
284 git svn clone -s svn://svn.berlios.de/openocd
287 Building OpenOCD from a repository requires a recent version of the
288 GNU autotools (autoconf >= 2.59 and automake >= 1.9).
289 For building on Windows,
290 you have to use Cygwin. Make sure that your @env{PATH} environment variable contains no
291 other locations with Unix utils (like UnxUtils) - these can't handle the Cygwin
292 paths, resulting in obscure dependency errors (This is an observation I've gathered
293 from the logs of one user - correct me if I'm wrong).
295 You further need the appropriate driver files, if you want to build support for
296 a FTDI FT2232 based interface:
299 @item @b{ftdi2232} libftdi (@uref{http://www.intra2net.com/opensource/ftdi/})
300 @item @b{ftd2xx} libftd2xx (@uref{http://www.ftdichip.com/Drivers/D2XX.htm})
301 @item When using the Amontec JTAGkey, you have to get the drivers from the Amontec
302 homepage (@uref{http://www.amontec.com}). The JTAGkey uses a non-standard VID/PID.
305 libftdi is supported under Windows. Do not use versions earlier than 0.14.
307 In general, the D2XX driver provides superior performance (several times as fast),
308 but has the draw-back of being binary-only - though that isn't that bad, as it isn't
309 a kernel module, only a user space library.
311 To build OpenOCD (on both Linux and Cygwin), use the following commands:
317 Bootstrap generates the configure script, and prepares building on your system.
320 ./configure [options, see below]
323 Configure generates the Makefiles used to build OpenOCD.
330 Make builds OpenOCD, and places the final executable in ./src/, the last step, ``make install'' is optional.
332 The configure script takes several options, specifying which JTAG interfaces
333 should be included (among other things):
337 @option{--enable-parport} - Enable building the PC parallel port driver.
339 @option{--enable-parport_ppdev} - Enable use of ppdev (/dev/parportN) for parport.
341 @option{--enable-parport_giveio} - Enable use of giveio for parport instead of ioperm.
343 @option{--enable-amtjtagaccel} - Enable building the Amontec JTAG-Accelerator driver.
345 @option{--enable-ecosboard} - Enable building support for eCosBoard based JTAG debugger.
347 @option{--enable-ioutil} - Enable ioutil functions - useful for standalone OpenOCD implementations.
349 @option{--enable-httpd} - Enable builtin httpd server - useful for standalone OpenOCD implementations.
351 @option{--enable-ep93xx} - Enable building support for EP93xx based SBCs.
353 @option{--enable-at91rm9200} - Enable building support for AT91RM9200 based SBCs.
355 @option{--enable-gw16012} - Enable building support for the Gateworks GW16012 JTAG programmer.
357 @option{--enable-ft2232_ftd2xx} - Numerous USB type ARM JTAG dongles use the FT2232C chip from this FTDICHIP.COM chip (closed source).
359 @option{--enable-ft2232_libftdi} - An open source (free) alternative to FTDICHIP.COM ftd2xx solution (Linux, MacOS, Cygwin).
361 @option{--with-ftd2xx-win32-zipdir=PATH} - If using FTDICHIP.COM ft2232c driver,
362 give the directory where the Win32 FTDICHIP.COM 'CDM' driver zip file was unpacked.
364 @option{--with-ftd2xx-linux-tardir=PATH} - If using FTDICHIP.COM ft2232c driver
365 on Linux, give the directory where the Linux driver's TAR.GZ file was unpacked.
367 @option{--with-ftd2xx-lib=shared|static} - Linux only. Default: static. Specifies how the FTDICHIP.COM libftd2xx driver should be linked. Note: 'static' only works in conjunction with @option{--with-ftd2xx-linux-tardir}. The 'shared' value is supported (12/26/2008), however you must manually install the required header files and shared libraries in an appropriate place. This uses ``libusb'' internally.
369 @option{--enable-presto_libftdi} - Enable building support for ASIX Presto programmer using the libftdi driver.
371 @option{--enable-presto_ftd2xx} - Enable building support for ASIX Presto programmer using the FTD2XX driver.
373 @option{--enable-usbprog} - Enable building support for the USBprog JTAG programmer.
375 @option{--enable-oocd_trace} - Enable building support for the OpenOCD+trace ETM capture device.
377 @option{--enable-jlink} - Enable building support for the Segger J-Link JTAG programmer.
379 @option{--enable-vsllink} - Enable building support for the Versaloon-Link JTAG programmer.
381 @option{--enable-rlink} - Enable building support for the Raisonance RLink JTAG programmer.
383 @option{--enable-arm-jtag-ew} - Enable building support for the Olimex ARM-JTAG-EW programmer.
385 @option{--enable-dummy} - Enable building the dummy port driver.
388 @section Parallel Port Dongles
390 If you want to access the parallel port using the PPDEV interface you have to specify
391 both the @option{--enable-parport} AND the @option{--enable-parport_ppdev} option since
392 the @option{--enable-parport_ppdev} option actually is an option to the parport driver
393 (see @uref{http://forum.sparkfun.com/viewtopic.php?t=3795} for more info).
395 The same is true for the @option{--enable-parport_giveio} option, you have to
396 use both the @option{--enable-parport} AND the @option{--enable-parport_giveio} option if you want to use giveio instead of ioperm parallel port access method.
398 @section FT2232C Based USB Dongles
400 There are 2 methods of using the FTD2232, either (1) using the
401 FTDICHIP.COM closed source driver, or (2) the open (and free) driver
402 libftdi. Some claim the (closed) FTDICHIP.COM solution is faster.
404 The FTDICHIP drivers come as either a (win32) ZIP file, or a (Linux)
405 TAR.GZ file. You must unpack them ``some where'' convient. As of this
406 writing (12/26/2008) FTDICHIP does not supply means to install these
407 files ``in an appropriate place'' As a result, there are two
408 ``./configure'' options that help.
410 Below is an example build process:
413 @item Check out the latest version of ``openocd'' from SVN.
415 @item If you are using the FTDICHIP.COM driver, download
416 and unpack the Windows or Linux FTD2xx drivers
417 (@uref{http://www.ftdichip.com/Drivers/D2XX.htm}).
418 If you are using the libftdi driver, install that package
419 (e.g. @command{apt-get install libftdi} on systems with APT).
422 /home/duane/ftd2xx.win32 => the Cygwin/Win32 ZIP file contents
423 /home/duane/libftd2xx0.4.16 => the Linux TAR.GZ file contents
426 @item Configure with options resembling the following.
429 @item Cygwin FTDICHIP solution:
431 ./configure --prefix=/home/duane/mytools \
432 --enable-ft2232_ftd2xx \
433 --with-ftd2xx-win32-zipdir=/home/duane/ftd2xx.win32
436 @item Linux FTDICHIP solution:
438 ./configure --prefix=/home/duane/mytools \
439 --enable-ft2232_ftd2xx \
440 --with-ft2xx-linux-tardir=/home/duane/libftd2xx0.4.16
443 @item Cygwin/Linux LIBFTDI solution ... assuming that
445 @item For Windows -- that the Windows port of LIBUSB is in place.
446 @item For Linux -- that libusb has been built/installed and is in place.
447 @item That libftdi has been built and installed (relies on libusb).
450 Then configure the libftdi solution like this:
453 ./configure --prefix=/home/duane/mytools \
454 --enable-ft2232_libftdi
458 @item Then just type ``make'', and perhaps ``make install''.
462 @section Miscellaneous Configure Options
466 @option{--disable-option-checking} - Ignore unrecognized @option{--enable} and @option{--with} options.
468 @option{--enable-gccwarnings} - Enable extra gcc warnings during build.
471 @option{--enable-release} - Enable building of an OpenOCD release, generally
472 this is for developers. It simply omits the svn version string when the
473 openocd @option{-v} is executed.
476 @node JTAG Hardware Dongles
477 @chapter JTAG Hardware Dongles
486 Defined: @b{dongle}: A small device that plugins into a computer and serves as
487 an adapter .... [snip]
489 In the OpenOCD case, this generally refers to @b{a small adapater} one
490 attaches to your computer via USB or the Parallel Printer Port. The
491 execption being the Zylin ZY1000 which is a small box you attach via
492 an ethernet cable. The Zylin ZY1000 has the advantage that it does not
493 require any drivers to be installed on the developer PC. It also has
494 a built in web interface. It supports RTCK/RCLK or adaptive clocking
495 and has a built in relay to power cycle targets remotely.
498 @section Choosing a Dongle
500 There are three things you should keep in mind when choosing a dongle.
503 @item @b{Voltage} What voltage is your target? 1.8, 2.8, 3.3, or 5V? Does your dongle support it?
504 @item @b{Connection} Printer Ports - Does your computer have one?
505 @item @b{Connection} Is that long printer bit-bang cable practical?
506 @item @b{RTCK} Do you require RTCK? Also known as ``adaptive clocking''
509 @section Stand alone Systems
511 @b{ZY1000} See: @url{http://www.zylin.com/zy1000.html} Technically, not a
512 dongle, but a standalone box. The ZY1000 has the advantage that it does
513 not require any drivers installed on the developer PC. It also has
514 a built in web interface. It supports RTCK/RCLK or adaptive clocking
515 and has a built in relay to power cycle targets remotely.
517 @section USB FT2232 Based
519 There are many USB JTAG dongles on the market, many of them are based
520 on a chip from ``Future Technology Devices International'' (FTDI)
521 known as the FTDI FT2232; this is a USB full speed (12 Mbps) chip.
522 See: @url{http://www.ftdichip.com} for more information.
523 In summer 2009, USB high speed (480 Mbps) versions of these FTDI
524 chips are starting to become available in JTAG adapters.
526 As of 28/Nov/2008, the following are supported:
530 @* Link @url{http://www.hs-augsburg.de/~hhoegl/proj/usbjtag/usbjtag.html}
532 @* See: @url{http://www.amontec.com/jtagkey.shtml}
534 @* See: @url{http://www.oocdlink.com} By Joern Kaipf
536 @* See: @url{http://www.signalyzer.com}
537 @item @b{evb_lm3s811}
538 @* See: @url{http://www.luminarymicro.com} - The Stellaris LM3S811 eval board has an FTD2232C chip built in.
539 @item @b{olimex-jtag}
540 @* See: @url{http://www.olimex.com}
542 @* See: @url{http://www.tincantools.com}
543 @item @b{turtelizer2}
545 @uref{http://www.ethernut.de/en/hardware/turtelizer/index.html, Turtelizer 2}, or
546 @url{http://www.ethernut.de}
548 @* Link: @url{http://www.hitex.com/index.php?id=383}
550 @* Link @url{http://www.hitex.com/stm32-stick}
551 @item @b{axm0432_jtag}
552 @* Axiom AXM-0432 Link @url{http://www.axman.com}
554 @* Link @url{http://www.hitex.com/index.php?id=cortino}
557 @section USB JLINK based
558 There are several OEM versions of the Segger @b{JLINK} adapter. It is
559 an example of a micro controller based JTAG adapter, it uses an
560 AT91SAM764 internally.
563 @item @b{ATMEL SAMICE} Only works with ATMEL chips!
564 @* Link: @url{http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3892}
565 @item @b{SEGGER JLINK}
566 @* Link: @url{http://www.segger.com/jlink.html}
568 @* Link: @url{http://www.iar.com/website1/1.0.1.0/369/1/index.php}
571 @section USB RLINK based
572 Raisonance has an adapter called @b{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.
575 @item @b{Raisonance RLink}
576 @* Link: @url{http://www.raisonance.com/products/RLink.php}
577 @item @b{STM32 Primer}
578 @* Link: @url{http://www.stm32circle.com/resources/stm32primer.php}
579 @item @b{STM32 Primer2}
580 @* Link: @url{http://www.stm32circle.com/resources/stm32primer2.php}
586 @* Link: @url{http://www.embedded-projects.net/usbprog} - which uses an Atmel MEGA32 and a UBN9604
588 @item @b{USB - Presto}
589 @* Link: @url{http://tools.asix.net/prg_presto.htm}
591 @item @b{Versaloon-Link}
592 @* Link: @url{http://www.simonqian.com/en/Versaloon}
594 @item @b{ARM-JTAG-EW}
595 @* Link: @url{http://www.olimex.com/dev/arm-jtag-ew.html}
598 @section IBM PC Parallel Printer Port Based
600 The two well known ``JTAG Parallel Ports'' cables are the Xilnx DLC5
601 and the MacGraigor Wiggler. There are many clones and variations of
606 @item @b{Wiggler} - There are many clones of this.
607 @* Link: @url{http://www.macraigor.com/wiggler.htm}
609 @item @b{DLC5} - From XILINX - There are many clones of this
610 @* Link: Search the web for: ``XILINX DLC5'' - it is no longer
611 produced, PDF schematics are easily found and it is easy to make.
613 @item @b{Amontec - JTAG Accelerator}
614 @* Link: @url{http://www.amontec.com/jtag_accelerator.shtml}
617 @* Link: @url{http://www.gateworks.com/products/avila_accessories/gw16042.php}
620 @*@uref{http://www.ccac.rwth-aachen.de/@/~michaels/@/index.php/hardware/@/armjtag,
621 Improved parallel-port wiggler-style JTAG adapter}
623 @item @b{Wiggler_ntrst_inverted}
624 @* Yet another variation - See the source code, src/jtag/parport.c
626 @item @b{old_amt_wiggler}
627 @* Unknown - probably not on the market today
630 @* Link: Most likely @url{http://www.olimex.com/dev/arm-jtag.html} [another wiggler clone]
633 @* Link: @url{http://www.amontec.com/chameleon.shtml}
639 @* ispDownload from Lattice Semiconductor
640 @url{http://www.latticesemi.com/lit/docs/@/devtools/dlcable.pdf}
643 @* From ST Microsystems;
644 @uref{http://www.st.com/stonline/@/products/literature/um/7889.pdf,
645 FlashLINK JTAG programing cable for PSD and uPSD}
653 @* An EP93xx based Linux machine using the GPIO pins directly.
656 @* Like the EP93xx - but an ATMEL AT91RM9200 based solution using the GPIO pins on the chip.
662 @cindex running OpenOCD
664 @cindex --debug_level
668 The @option{--help} option shows:
672 --help | -h display this help
673 --version | -v display OpenOCD version
674 --file | -f use configuration file <name>
675 --search | -s dir to search for config files and scripts
676 --debug | -d set debug level <0-3>
677 --log_output | -l redirect log output to file <name>
678 --command | -c run <command>
679 --pipe | -p use pipes when talking to gdb
682 By default OpenOCD reads the file configuration file ``openocd.cfg''
683 in the current directory. To specify a different (or multiple)
684 configuration file, you can use the ``-f'' option. For example:
687 openocd -f config1.cfg -f config2.cfg -f config3.cfg
690 Once started, OpenOCD runs as a daemon, waiting for connections from
691 clients (Telnet, GDB, Other).
693 If you are having problems, you can enable internal debug messages via
696 Also it is possible to interleave commands w/config scripts using the
697 @option{-c} command line switch.
699 To enable debug output (when reporting problems or working on OpenOCD
700 itself), use the @option{-d} command line switch. This sets the
701 @option{debug_level} to "3", outputting the most information,
702 including debug messages. The default setting is "2", outputting only
703 informational messages, warnings and errors. You can also change this
704 setting from within a telnet or gdb session using @option{debug_level
705 <n>} @xref{debug_level}.
707 You can redirect all output from the daemon to a file using the
708 @option{-l <logfile>} switch.
710 Search paths for config/script files can be added to OpenOCD by using
711 the @option{-s <search>} switch. The current directory and the OpenOCD
712 target library is in the search path by default.
714 For details on the @option{-p} option. @xref{Connecting to GDB}.
716 Note! OpenOCD will launch the GDB & telnet server even if it can not
717 establish a connection with the target. In general, it is possible for
718 the JTAG controller to be unresponsive until the target is set up
719 correctly via e.g. GDB monitor commands in a GDB init script.
721 @node Simple Configuration Files
722 @chapter Simple Configuration Files
723 @cindex configuration
726 There are 4 basic ways of ``configurating'' OpenOCD to run, they are:
729 @item A small openocd.cfg file which ``sources'' other configuration files
730 @item A monolithic openocd.cfg file
731 @item Many -f filename options on the command line
732 @item Your Mixed Solution
735 @section Small configuration file method
737 This is the preferred method. It is simple and works well for many
738 people. The developers of OpenOCD would encourage you to use this
739 method. If you create a new configuration please email new
740 configurations to the development list.
742 Here is an example of an openocd.cfg file for an ATMEL at91sam7x256
745 source [find interface/signalyzer.cfg]
747 # GDB can also flash my flash!
748 gdb_memory_map enable
749 gdb_flash_program enable
751 source [find target/sam7x256.cfg]
754 There are many example configuration scripts you can work with. You
755 should look in the directory: @t{$(INSTALLDIR)/lib/openocd}. You
759 @item @b{board} - eval board level configurations
760 @item @b{interface} - specific dongle configurations
761 @item @b{target} - the target chips
762 @item @b{tcl} - helper scripts
763 @item @b{xscale} - things specific to the xscale.
766 Look first in the ``boards'' area, then the ``targets'' area. Often a board
767 configuration is a good example to work from.
769 @section Many -f filename options
770 Some believe this is a wonderful solution, others find it painful.
772 You can use a series of ``-f filename'' options on the command line,
773 OpenOCD will read each filename in sequence, for example:
776 openocd -f file1.cfg -f file2.cfg -f file2.cfg
779 You can also intermix various commands with the ``-c'' command line
782 @section Monolithic file
783 The ``Monolithic File'' dispenses with all ``source'' statements and
784 puts everything in one self contained (monolithic) file. This is not
787 Please try to ``source'' various files or use the multiple -f
790 @section Advice for you
791 Often, one uses a ``mixed approach''. Where possible, please try to
792 ``source'' common things, and if needed cut/paste parts of the
793 standard distribution configuration files as needed.
795 @b{REMEMBER:} The ``important parts'' of your configuration file are:
798 @item @b{Interface} - Defines the dongle
799 @item @b{Taps} - Defines the JTAG Taps
800 @item @b{GDB Targets} - What GDB talks to
801 @item @b{Flash Programing} - Very Helpful
804 Some key things you should look at and understand are:
807 @item The reset configuration of your debug environment as a whole
808 @item Is there a ``work area'' that OpenOCD can use?
809 @* For ARM - work areas mean up to 10x faster downloads.
810 @item For MMU/MPU based ARM chips (i.e.: ARM9 and later) will that work area still be available?
811 @item For complex targets (multiple chips) the JTAG SPEED becomes an issue.
816 @node Config File Guidelines
817 @chapter Config File Guidelines
819 This section/chapter is aimed at developers and integrators of
820 OpenOCD. These are guidelines for creating new boards and new target
821 configurations as of 28/Nov/2008.
823 However, you, the user of OpenOCD, should be somewhat familiar with
824 this section as it should help explain some of the internals of what
825 you might be looking at.
827 The user should find the following directories under @t{$(INSTALLDIR)/lib/openocd} :
831 @*Think JTAG Dongle. Files that configure the JTAG dongle go here.
833 @* Think Circuit Board, PWA, PCB, they go by many names. Board files
834 contain initialization items that are specific to a board - for
835 example: The SDRAM initialization sequence for the board, or the type
836 of external flash and what address it is found at. Any initialization
837 sequence to enable that external flash or SDRAM should be found in the
838 board file. Boards may also contain multiple targets, i.e.: Two CPUs, or
839 a CPU and an FPGA or CPLD.
841 @* Think chip. The ``target'' directory represents the JTAG TAPs
843 which OpenOCD should control, not a board. Two common types of targets
844 are ARM chips and FPGA or CPLD chips.
845 When a chip has multiple TAPs (maybe it has both ARM and DSP cores),
846 the target config file defines all of them.
849 @b{If needed...} The user in their ``openocd.cfg'' file or the board
850 file might override a specific feature in any of the above files by
851 setting a variable or two before sourcing the target file. Or adding
852 various commands specific to their situation.
854 @section Interface Config Files
856 The user should be able to source one of these files via a command like this:
859 source [find interface/FOOBAR.cfg]
861 openocd -f interface/FOOBAR.cfg
864 A preconfigured interface file should exist for every interface in use
865 today, that said, perhaps some interfaces have only been used by the
866 sole developer who created it.
868 Interface files should be found in @t{$(INSTALLDIR)/lib/openocd/interface}
870 @section Board Config Files
872 @b{Note: BOARD directory NEW as of 28/nov/2008}
874 The user should be able to source one of these files via a command like this:
877 source [find board/FOOBAR.cfg]
879 openocd -f board/FOOBAR.cfg
883 The board file should contain one or more @t{source [find
884 target/FOO.cfg]} statements along with any board specific things.
886 In summary the board files should contain (if present)
889 @item External flash configuration (i.e.: NOR flash on CS0, two NANDs on CS2)
890 @item SDRAM configuration (size, speed, etc.
891 @item Board specific IO configuration (i.e.: GPIO pins might disable a 2nd flash)
892 @item Multiple TARGET source statements
893 @item Reset configuration
894 @item All things that are not ``inside a chip''
895 @item Things inside a chip go in a 'target' file
898 @section Target Config Files
900 The user should be able to source one of these files via a command like this:
903 source [find target/FOOBAR.cfg]
905 openocd -f target/FOOBAR.cfg
908 In summary the target files should contain
912 @item Add TAPs to the scan chain
913 @item Add CPU targets
914 @item CPU/Chip/CPU-Core specific features
918 @subsection Important variable names
920 By default, the end user should never need to set these
921 variables. However, if the user needs to override a setting they only
922 need to set the variable in a simple way.
926 @* This gives a name to the overall chip, and is used as part of the
927 tap identifier dotted name.
929 @* By default little - unless the chip or board is not normally used that way.
931 @* When OpenOCD examines the JTAG chain, it will attempt to identify
932 every chip. If the @t{-expected-id} is nonzero, OpenOCD attempts
933 to verify the tap id number verses configuration file and may issue an
934 error or warning like this. The hope is that this will help to pinpoint
935 problems in OpenOCD configurations.
938 Info: JTAG tap: sam7x256.cpu tap/device found: 0x3f0f0f0f
939 (Manufacturer: 0x787, Part: 0xf0f0, Version: 0x3)
940 Error: ERROR: Tap: sam7x256.cpu - Expected id: 0x12345678,
942 Error: ERROR: expected: mfg: 0x33c, part: 0x2345, ver: 0x1
943 Error: ERROR: got: mfg: 0x787, part: 0xf0f0, ver: 0x3
946 @item @b{_TARGETNAME}
947 @* By convention, this variable is created by the target configuration
948 script. The board configuration file may make use of this variable to
949 configure things like a ``reset init'' script, or other things
950 specific to that board and that target.
952 If the chip has 2 targets, use the names @b{_TARGETNAME0},
953 @b{_TARGETNAME1}, ... etc.
955 @b{Remember:} The ``board file'' may include multiple targets.
957 At no time should the name ``target0'' (the default target name if
958 none was specified) be used. The name ``target0'' is a hard coded name
959 - the next target on the board will be some other number.
960 In the same way, avoid using target numbers even when they are
961 permitted; use the right target name(s) for your board.
963 The user (or board file) should reasonably be able to:
966 source [find target/FOO.cfg]
967 $_TARGETNAME configure ... FOO specific parameters
969 source [find target/BAR.cfg]
970 $_TARGETNAME configure ... BAR specific parameters
975 @subsection Tcl Variables Guide Line
976 The Full Tcl/Tk language supports ``namespaces'' - JIM-Tcl does not.
978 Thus the rule we follow in OpenOCD is this: Variables that begin with
979 a leading underscore are temporary in nature, and can be modified and
980 used at will within a ?TARGET? configuration file.
982 @b{EXAMPLE:} The user should be able to do this:
986 # PXA270 #1 network side, big endian
987 # PXA270 #2 video side, little endian
991 source [find target/pxa270.cfg]
992 # variable: _TARGETNAME = network.cpu
993 # other commands can refer to the "network.cpu" tap.
994 $_TARGETNAME configure .... params for this CPU..
998 source [find target/pxa270.cfg]
999 # variable: _TARGETNAME = video.cpu
1000 # other commands can refer to the "video.cpu" tap.
1001 $_TARGETNAME configure .... params for this CPU..
1005 source [find target/spartan3.cfg]
1007 # Since $_TARGETNAME is temporal..
1008 # these names still work!
1009 network.cpu configure ... params
1010 video.cpu configure ... params
1013 @subsection Default Value Boiler Plate Code
1015 All target configuration files should start with this (or a modified form)
1019 if @{ [info exists CHIPNAME] @} @{
1020 set _CHIPNAME $CHIPNAME
1022 set _CHIPNAME sam7x256
1025 if @{ [info exists ENDIAN] @} @{
1031 if @{ [info exists CPUTAPID ] @} @{
1032 set _CPUTAPID $CPUTAPID
1034 set _CPUTAPID 0x3f0f0f0f
1038 @subsection Adding TAPs to the Scan Chain
1039 After the ``defaults'' are set up,
1040 add the TAPs on each chip to the JTAG scan chain.
1041 @xref{TAP Declaration}, and the naming convention
1044 In the simplest case the chip has only one TAP,
1045 probably for a CPU or FPGA.
1046 The config file for the Atmel AT91SAM7X256
1047 looks (in part) like this:
1050 jtag newtap $_CHIPNAME cpu -irlen 4 -ircapture 0x1 -irmask 0xf \
1051 -expected-id $_CPUTAPID
1054 A board with two such at91sam7 chips would be able
1055 to source such a config file twice, with different
1056 values for @code{CHIPNAME}, so
1057 it adds a different TAP each time.
1059 There are more complex examples too, with chips that have
1060 multiple TAPs. Ones worth looking at include:
1063 @item @file{target/omap3530.cfg} -- with a disabled ARM, and a JRC
1064 (there's a DSP too, which is not listed)
1065 @item @file{target/str912.cfg} -- with flash, CPU, and boundary scan
1066 @item @file{target/ti_dm355.cfg} -- with ETM, ARM, and JRC (this JRC
1067 is not currently used)
1070 @subsection Add CPU targets
1072 After adding a TAP for a CPU, you should set it up so that
1073 GDB and other commands can use it.
1074 @xref{CPU Configuration}.
1075 For the at91sam7 example above, the command can look like this:
1078 set _TARGETNAME $_CHIPNAME.cpu
1079 target create $_TARGETNAME arm7tdmi -chain-position $_TARGETNAME
1082 Work areas are small RAM areas associated with CPU targets.
1083 They are used by OpenOCD to speed up downloads,
1084 and to download small snippets of code to program flash chips.
1085 If the chip includes a form of ``on-chip-ram'' - and many do - define
1086 a work area if you can.
1087 Again using the at91sam7 as an example, this can look like:
1090 $_TARGETNAME configure -work-area-phys 0x00200000 \
1091 -work-area-size 0x4000 -work-area-backup 0
1094 @subsection Reset Configuration
1096 As a rule, you should put the @command{reset_config} command
1097 into the board file. Most things you think you know about a
1098 chip can be tweaked by the board.
1100 Some chips have specific ways the TRST and SRST signals are
1101 managed. In the unusual case that these are @emph{chip specific}
1102 and can never be changed by board wiring, they could go here.
1104 @subsection ARM Core Specific Hacks
1106 If the chip has a DCC, enable it. If the chip is an ARM9 with some
1107 special high speed download features - enable it.
1109 If the chip has an ARM ``vector catch'' feature - by default enable
1110 it for Undefined Instructions, Data Abort, and Prefetch Abort, if the
1111 user is really writing a handler for those situations - they can
1112 easily disable it. Experiance has shown the ``vector catch'' is
1113 helpful - for common programing errors.
1115 If present, the MMU, the MPU and the CACHE should be disabled.
1117 Some ARM cores are equipped with trace support, which permits
1118 examination of the instruction and data bus activity. Trace
1119 activity is controlled through an ``Embedded Trace Module'' (ETM)
1120 on one of the core's scan chains. The ETM emits voluminous data
1121 through a ``trace port''. (@xref{ARM Tracing}.)
1122 If you are using an external trace port,
1123 configure it in your board config file.
1124 If you are using an on-chip ``Embedded Trace Buffer'' (ETB),
1125 configure it in your target config file.
1128 etm config $_TARGETNAME 16 normal full etb
1129 etb config $_TARGETNAME $_CHIPNAME.etb
1132 @subsection Internal Flash Configuration
1134 This applies @b{ONLY TO MICROCONTROLLERS} that have flash built in.
1136 @b{Never ever} in the ``target configuration file'' define any type of
1137 flash that is external to the chip. (For example a BOOT flash on
1138 Chip Select 0.) Such flash information goes in a board file - not
1139 the TARGET (chip) file.
1143 @item at91sam7x256 - has 256K flash YES enable it.
1144 @item str912 - has flash internal YES enable it.
1145 @item imx27 - uses boot flash on CS0 - it goes in the board file.
1146 @item pxa270 - again - CS0 flash - it goes in the board file.
1150 @chapter About JIM-Tcl
1154 OpenOCD includes a small ``TCL Interpreter'' known as JIM-TCL. You can
1155 learn more about JIM here: @url{http://jim.berlios.de}
1158 @item @b{JIM vs. Tcl}
1159 @* JIM-TCL is a stripped down version of the well known Tcl language,
1160 which can be found here: @url{http://www.tcl.tk}. JIM-Tcl has far
1161 fewer features. JIM-Tcl is a single .C file and a single .H file and
1162 impliments the basic Tcl command set along. In contrast: Tcl 8.6 is a
1163 4.2 MB .zip file containing 1540 files.
1165 @item @b{Missing Features}
1166 @* Our practice has been: Add/clone the real Tcl feature if/when
1167 needed. We welcome JIM Tcl improvements, not bloat.
1170 @* OpenOCD configuration scripts are JIM Tcl Scripts. OpenOCD's
1171 command interpreter today (28/nov/2008) is a mixture of (newer)
1172 JIM-Tcl commands, and (older) the orginal command interpreter.
1175 @* At the OpenOCD telnet command line (or via the GDB mon command) one
1176 can type a Tcl for() loop, set variables, etc.
1178 @item @b{Historical Note}
1179 @* JIM-Tcl was introduced to OpenOCD in spring 2008.
1181 @item @b{Need a crash course in Tcl?}
1182 @*@xref{Tcl Crash Course}.
1185 @node Daemon Configuration
1186 @chapter Daemon Configuration
1187 @cindex initialization
1188 The commands here are commonly found in the openocd.cfg file and are
1189 used to specify what TCP/IP ports are used, and how GDB should be
1192 @section Configuration Stage
1193 @cindex configuration stage
1194 @cindex configuration command
1196 When the OpenOCD server process starts up, it enters a
1197 @emph{configuration stage} which is the only time that
1198 certain commands, @emph{configuration commands}, may be issued.
1199 Those configuration commands include declaration of TAPs
1200 and other basic setup.
1201 The server must leave the configuration stage before it
1202 may access or activate TAPs.
1203 After it leaves this stage, configuration commands may no
1206 @deffn {Config Command} init
1207 This command terminates the configuration stage and
1208 enters the normal command mode. This can be useful to add commands to
1209 the startup scripts and commands such as resetting the target,
1210 programming flash, etc. To reset the CPU upon startup, add "init" and
1211 "reset" at the end of the config script or at the end of the OpenOCD
1212 command line using the @option{-c} command line switch.
1214 If this command does not appear in any startup/configuration file
1215 OpenOCD executes the command for you after processing all
1216 configuration files and/or command line options.
1218 @b{NOTE:} This command normally occurs at or near the end of your
1219 openocd.cfg file to force OpenOCD to ``initialize'' and make the
1220 targets ready. For example: If your openocd.cfg file needs to
1221 read/write memory on your target, @command{init} must occur before
1222 the memory read/write commands. This includes @command{nand probe}.
1225 @section TCP/IP Ports
1229 The OpenOCD server accepts remote commands in several syntaxes.
1230 Each syntax uses a different TCP/IP port, which you may specify
1231 only during configuration (before those ports are opened).
1233 @deffn {Command} gdb_port (number)
1235 Specify or query the first port used for incoming GDB connections.
1236 The GDB port for the
1237 first target will be gdb_port, the second target will listen on gdb_port + 1, and so on.
1238 When not specified during the configuration stage,
1239 the port @var{number} defaults to 3333.
1242 @deffn {Command} tcl_port (number)
1243 Specify or query the port used for a simplified RPC
1244 connection that can be used by clients to issue TCL commands and get the
1245 output from the Tcl engine.
1246 Intended as a machine interface.
1247 When not specified during the configuration stage,
1248 the port @var{number} defaults to 6666.
1251 @deffn {Command} telnet_port (number)
1252 Specify or query the
1253 port on which to listen for incoming telnet connections.
1254 This port is intended for interaction with one human through TCL commands.
1255 When not specified during the configuration stage,
1256 the port @var{number} defaults to 4444.
1259 @anchor{GDB Configuration}
1260 @section GDB Configuration
1262 @cindex GDB configuration
1263 You can reconfigure some GDB behaviors if needed.
1264 The ones listed here are static and global.
1265 @xref{Target Configuration}, about configuring individual targets.
1266 @xref{Target Events}, about configuring target-specific event handling.
1268 @anchor{gdb_breakpoint_override}
1269 @deffn {Command} gdb_breakpoint_override [@option{hard}|@option{soft}|@option{disable}]
1270 Force breakpoint type for gdb @command{break} commands.
1271 This option supports GDB GUIs which don't
1272 distinguish hard versus soft breakpoints, if the default OpenOCD and
1273 GDB behaviour is not sufficient. GDB normally uses hardware
1274 breakpoints if the memory map has been set up for flash regions.
1277 @deffn {Config command} gdb_detach (@option{resume}|@option{reset}|@option{halt}|@option{nothing})
1278 Configures what OpenOCD will do when GDB detaches from the daemon.
1279 Default behaviour is @option{resume}.
1282 @anchor{gdb_flash_program}
1283 @deffn {Config command} gdb_flash_program (@option{enable}|@option{disable})
1284 Set to @option{enable} to cause OpenOCD to program the flash memory when a
1285 vFlash packet is received.
1286 The default behaviour is @option{enable}.
1289 @deffn {Config command} gdb_memory_map (@option{enable}|@option{disable})
1290 Set to @option{enable} to cause OpenOCD to send the memory configuration to GDB when
1291 requested. GDB will then know when to set hardware breakpoints, and program flash
1292 using the GDB load command. @command{gdb_flash_program enable} must also be enabled
1293 for flash programming to work.
1294 Default behaviour is @option{enable}.
1295 @xref{gdb_flash_program}.
1298 @deffn {Config command} gdb_report_data_abort (@option{enable}|@option{disable})
1299 Specifies whether data aborts cause an error to be reported
1300 by GDB memory read packets.
1301 The default behaviour is @option{disable};
1302 use @option{enable} see these errors reported.
1305 @anchor{Event Polling}
1306 @section Event Polling
1308 Hardware debuggers are parts of asynchronous systems,
1309 where significant events can happen at any time.
1310 The OpenOCD server needs to detect some of these events,
1311 so it can report them to through TCL command line
1314 Examples of such events include:
1317 @item One of the targets can stop running ... maybe it triggers
1318 a code breakpoint or data watchpoint, or halts itself.
1319 @item Messages may be sent over ``debug message'' channels ... many
1320 targets support such messages sent over JTAG,
1321 for receipt by the person debugging or tools.
1322 @item Loss of power ... some adapters can detect these events.
1323 @item Resets not issued through JTAG ... such reset sources
1324 can include button presses or other system hardware, sometimes
1325 including the target itself (perhaps through a watchdog).
1326 @item Debug instrumentation sometimes supports event triggering
1327 such as ``trace buffer full'' (so it can quickly be emptied)
1328 or other signals (to correlate with code behavior).
1331 None of those events are signaled through standard JTAG signals.
1332 However, most conventions for JTAG connectors include voltage
1333 level and system reset (SRST) signal detection.
1334 Some connectors also include instrumentation signals, which
1335 can imply events when those signals are inputs.
1337 In general, OpenOCD needs to periodically check for those events,
1338 either by looking at the status of signals on the JTAG connector
1339 or by sending synchronous ``tell me your status'' JTAG requests
1340 to the various active targets.
1341 There is a command to manage and monitor that polling,
1342 which is normally done in the background.
1344 @deffn Command poll [@option{on}|@option{off}]
1345 Poll the current target for its current state.
1346 (Also, @pxref{target curstate}.)
1347 If that target is in debug mode, architecture
1348 specific information about the current state is printed.
1349 An optional parameter
1350 allows background polling to be enabled and disabled.
1352 You could use this from the TCL command shell, or
1353 from GDB using @command{monitor poll} command.
1356 background polling: on
1357 target state: halted
1358 target halted in ARM state due to debug-request, \
1359 current mode: Supervisor
1360 cpsr: 0x800000d3 pc: 0x11081bfc
1361 MMU: disabled, D-Cache: disabled, I-Cache: enabled
1366 @node Interface - Dongle Configuration
1367 @chapter Interface - Dongle Configuration
1368 JTAG Adapters/Interfaces/Dongles are normally configured
1369 through commands in an interface configuration
1370 file which is sourced by your @file{openocd.cfg} file, or
1371 through a command line @option{-f interface/....cfg} option.
1374 source [find interface/olimex-jtag-tiny.cfg]
1378 OpenOCD what type of JTAG adapter you have, and how to talk to it.
1379 A few cases are so simple that you only need to say what driver to use:
1386 Most adapters need a bit more configuration than that.
1389 @section Interface Configuration
1391 The interface command tells OpenOCD what type of JTAG dongle you are
1392 using. Depending on the type of dongle, you may need to have one or
1393 more additional commands.
1395 @deffn {Config Command} {interface} name
1396 Use the interface driver @var{name} to connect to the
1400 @deffn Command {interface_list}
1401 List the interface drivers that have been built into
1402 the running copy of OpenOCD.
1405 @deffn Command {jtag interface}
1406 Returns the name of the interface driver being used.
1409 @section Interface Drivers
1411 Each of the interface drivers listed here must be explicitly
1412 enabled when OpenOCD is configured, in order to be made
1413 available at run time.
1415 @deffn {Interface Driver} {amt_jtagaccel}
1416 Amontec Chameleon in its JTAG Accelerator configuration,
1417 connected to a PC's EPP mode parallel port.
1418 This defines some driver-specific commands:
1420 @deffn {Config Command} {parport_port} number
1421 Specifies either the address of the I/O port (default: 0x378 for LPT1) or
1422 the number of the @file{/dev/parport} device.
1425 @deffn {Config Command} rtck [@option{enable}|@option{disable}]
1426 Displays status of RTCK option.
1427 Optionally sets that option first.
1431 @deffn {Interface Driver} {arm-jtag-ew}
1432 Olimex ARM-JTAG-EW USB adapter
1433 This has one driver-specific command:
1435 @deffn Command {armjtagew_info}
1440 @deffn {Interface Driver} {at91rm9200}
1441 Supports bitbanged JTAG from the local system,
1442 presuming that system is an Atmel AT91rm9200
1443 and a specific set of GPIOs is used.
1444 @c command: at91rm9200_device NAME
1445 @c chooses among list of bit configs ... only one option
1448 @deffn {Interface Driver} {dummy}
1449 A dummy software-only driver for debugging.
1452 @deffn {Interface Driver} {ep93xx}
1453 Cirrus Logic EP93xx based single-board computer bit-banging (in development)
1456 @deffn {Interface Driver} {ft2232}
1457 FTDI FT2232 (USB) based devices over one of the userspace libraries.
1458 These interfaces have several commands, used to configure the driver
1459 before initializing the JTAG scan chain:
1461 @deffn {Config Command} {ft2232_device_desc} description
1462 Provides the USB device description (the @emph{iProduct string})
1463 of the FTDI FT2232 device. If not
1464 specified, the FTDI default value is used. This setting is only valid
1465 if compiled with FTD2XX support.
1468 @deffn {Config Command} {ft2232_serial} serial-number
1469 Specifies the @var{serial-number} of the FTDI FT2232 device to use,
1470 in case the vendor provides unique IDs and more than one FT2232 device
1471 is connected to the host.
1472 If not specified, serial numbers are not considered.
1475 @deffn {Config Command} {ft2232_layout} name
1476 Each vendor's FT2232 device can use different GPIO signals
1477 to control output-enables, reset signals, and LEDs.
1478 Currently valid layout @var{name} values include:
1480 @item @b{axm0432_jtag} Axiom AXM-0432
1481 @item @b{comstick} Hitex STR9 comstick
1482 @item @b{cortino} Hitex Cortino JTAG interface
1483 @item @b{evb_lm3s811} Luminary Micro EVB_LM3S811 as a JTAG interface,
1484 either for the local Cortex-M3 (SRST only)
1485 or in a passthrough mode (neither SRST nor TRST)
1486 @item @b{flyswatter} Tin Can Tools Flyswatter
1487 @item @b{icebear} ICEbear JTAG adapter from Section 5
1488 @item @b{jtagkey} Amontec JTAGkey and JTAGkey-Tiny (and compatibles)
1489 @item @b{m5960} American Microsystems M5960
1490 @item @b{olimex-jtag} Olimex ARM-USB-OCD and ARM-USB-Tiny
1491 @item @b{oocdlink} OOCDLink
1492 @c oocdlink ~= jtagkey_prototype_v1
1493 @item @b{sheevaplug} Marvell Sheevaplug development kit
1494 @item @b{signalyzer} Xverve Signalyzer
1495 @item @b{stm32stick} Hitex STM32 Performance Stick
1496 @item @b{turtelizer2} egnite Software turtelizer2
1497 @item @b{usbjtag} "USBJTAG-1" layout described in the OpenOCD diploma thesis
1501 @deffn {Config Command} {ft2232_vid_pid} [vid pid]+
1502 The vendor ID and product ID of the FTDI FT2232 device. If not specified, the FTDI
1503 default values are used.
1504 Currently, up to eight [@var{vid}, @var{pid}] pairs may be given, e.g.
1506 ft2232_vid_pid 0x0403 0xcff8 0x15ba 0x0003
1510 @deffn {Config Command} {ft2232_latency} ms
1511 On some systems using FT2232 based JTAG interfaces the FT_Read function call in
1512 ft2232_read() fails to return the expected number of bytes. This can be caused by
1513 USB communication delays and has proved hard to reproduce and debug. Setting the
1514 FT2232 latency timer to a larger value increases delays for short USB packets but it
1515 also reduces the risk of timeouts before receiving the expected number of bytes.
1516 The OpenOCD default value is 2 and for some systems a value of 10 has proved useful.
1519 For example, the interface config file for a
1520 Turtelizer JTAG Adapter looks something like this:
1524 ft2232_device_desc "Turtelizer JTAG/RS232 Adapter"
1525 ft2232_layout turtelizer2
1526 ft2232_vid_pid 0x0403 0xbdc8
1530 @deffn {Interface Driver} {gw16012}
1531 Gateworks GW16012 JTAG programmer.
1532 This has one driver-specific command:
1534 @deffn {Config Command} {parport_port} number
1535 Specifies either the address of the I/O port (default: 0x378 for LPT1) or
1536 the number of the @file{/dev/parport} device.
1540 @deffn {Interface Driver} {jlink}
1541 Segger jlink USB adapter
1542 @c command: jlink_info
1544 @c command: jlink_hw_jtag (2|3)
1545 @c sets version 2 or 3
1548 @deffn {Interface Driver} {parport}
1549 Supports PC parallel port bit-banging cables:
1550 Wigglers, PLD download cable, and more.
1551 These interfaces have several commands, used to configure the driver
1552 before initializing the JTAG scan chain:
1554 @deffn {Config Command} {parport_cable} name
1555 The layout of the parallel port cable used to connect to the target.
1556 Currently valid cable @var{name} values include:
1559 @item @b{altium} Altium Universal JTAG cable.
1560 @item @b{arm-jtag} Same as original wiggler except SRST and
1561 TRST connections reversed and TRST is also inverted.
1562 @item @b{chameleon} The Amontec Chameleon's CPLD when operated
1563 in configuration mode. This is only used to
1564 program the Chameleon itself, not a connected target.
1565 @item @b{dlc5} The Xilinx Parallel cable III.
1566 @item @b{flashlink} The ST Parallel cable.
1567 @item @b{lattice} Lattice ispDOWNLOAD Cable
1568 @item @b{old_amt_wiggler} The Wiggler configuration that comes with
1570 Amontec's Chameleon Programmer. The new version available from
1571 the website uses the original Wiggler layout ('@var{wiggler}')
1572 @item @b{triton} The parallel port adapter found on the
1573 ``Karo Triton 1 Development Board''.
1574 This is also the layout used by the HollyGates design
1575 (see @uref{http://www.lartmaker.nl/projects/jtag/}).
1576 @item @b{wiggler} The original Wiggler layout, also supported by
1577 several clones, such as the Olimex ARM-JTAG
1578 @item @b{wiggler2} Same as original wiggler except an led is fitted on D5.
1579 @item @b{wiggler_ntrst_inverted} Same as original wiggler except TRST is inverted.
1583 @deffn {Config Command} {parport_port} number
1584 Either the address of the I/O port (default: 0x378 for LPT1) or the number of
1585 the @file{/dev/parport} device
1587 When using PPDEV to access the parallel port, use the number of the parallel port:
1588 @option{parport_port 0} (the default). If @option{parport_port 0x378} is specified
1589 you may encounter a problem.
1592 @deffn {Config Command} {parport_write_on_exit} (on|off)
1593 This will configure the parallel driver to write a known
1594 cable-specific value to the parallel interface on exiting OpenOCD
1597 For example, the interface configuration file for a
1598 classic ``Wiggler'' cable might look something like this:
1603 parport_cable wiggler
1607 @deffn {Interface Driver} {presto}
1608 ASIX PRESTO USB JTAG programmer.
1609 @c command: presto_serial str
1610 @c sets serial number
1613 @deffn {Interface Driver} {rlink}
1614 Raisonance RLink USB adapter
1617 @deffn {Interface Driver} {usbprog}
1618 usbprog is a freely programmable USB adapter.
1621 @deffn {Interface Driver} {vsllink}
1622 vsllink is part of Versaloon which is a versatile USB programmer.
1625 This defines quite a few driver-specific commands,
1626 which are not currently documented here.
1630 @deffn {Interface Driver} {ZY1000}
1631 This is the Zylin ZY1000 JTAG debugger.
1634 This defines some driver-specific commands,
1635 which are not currently documented here.
1638 @deffn Command power [@option{on}|@option{off}]
1639 Turn power switch to target on/off.
1640 No arguments: print status.
1647 JTAG clock setup is part of system setup.
1648 It @emph{does not belong with interface setup} since any interface
1649 only knows a few of the constraints for the JTAG clock speed.
1650 Sometimes the JTAG speed is
1651 changed during the target initialization process: (1) slow at
1652 reset, (2) program the CPU clocks, (3) run fast.
1653 Both the "slow" and "fast" clock rates are functions of the
1654 oscillators used, the chip, the board design, and sometimes
1655 power management software that may be active.
1657 The speed used during reset can be adjusted using pre_reset
1658 and post_reset event handlers.
1659 @xref{Target Events}.
1661 If your system supports adaptive clocking (RTCK), configuring
1662 JTAG to use that is probably the most robust approach.
1663 However, it introduces delays to synchronize clocks; so it
1664 may not be the fastest solution.
1666 @b{NOTE:} Script writers should consider using @command{jtag_rclk}
1667 instead of @command{jtag_khz}.
1669 @deffn {Command} jtag_khz max_speed_kHz
1670 A non-zero speed is in KHZ. Hence: 3000 is 3mhz.
1671 JTAG interfaces usually support a limited number of
1672 speeds. The speed actually used won't be faster
1673 than the speed specified.
1675 As a rule of thumb, if you specify a clock rate make
1676 sure the JTAG clock is no more than @math{1/6th CPU-Clock}.
1677 This is especially true for synthesized cores (ARMxxx-S).
1679 Speed 0 (khz) selects RTCK method.
1681 If your system uses RTCK, you won't need to change the
1682 JTAG clocking after setup.
1683 Not all interfaces, boards, or targets support ``rtck''.
1684 If the interface device can not
1685 support it, an error is returned when you try to use RTCK.
1688 @defun jtag_rclk fallback_speed_kHz
1690 This Tcl proc (defined in startup.tcl) attempts to enable RTCK/RCLK.
1691 If that fails (maybe the interface, board, or target doesn't
1692 support it), falls back to the specified frequency.
1694 # Fall back to 3mhz if RTCK is not supported
1699 @node Reset Configuration
1700 @chapter Reset Configuration
1701 @cindex Reset Configuration
1703 Every system configuration may require a different reset
1704 configuration. This can also be quite confusing.
1705 Resets also interact with @var{reset-init} event handlers,
1706 which do things like setting up clocks and DRAM, and
1707 JTAG clock rates. (@xref{JTAG Speed}.)
1708 Please see the various board files for examples.
1711 To maintainers and integrators:
1712 Reset configuration touches several things at once.
1713 Normally the board configuration file
1714 should define it and assume that the JTAG adapter supports
1715 everything that's wired up to the board's JTAG connector.
1716 However, the target configuration file could also make note
1717 of something the silicon vendor has done inside the chip,
1718 which will be true for most (or all) boards using that chip.
1719 And when the JTAG adapter doesn't support everything, the
1720 system configuration file will need to override parts of
1721 the reset configuration provided by other files.
1724 @section Types of Reset
1726 There are many kinds of reset possible through JTAG, but
1727 they may not all work with a given board and adapter.
1728 That's part of why reset configuration can be error prone.
1732 @emph{System Reset} ... the @emph{SRST} hardware signal
1733 resets all chips connected to the JTAG adapter, such as processors,
1734 power management chips, and I/O controllers. Normally resets triggered
1735 with this signal behave exactly like pressing a RESET button.
1737 @emph{JTAG TAP Reset} ... the @emph{TRST} hardware signal resets
1738 just the TAP controllers connected to the JTAG adapter.
1739 Such resets should not be visible to the rest of the system; resetting a
1740 device's the TAP controller just puts that controller into a known state.
1742 @emph{Emulation Reset} ... many devices can be reset through JTAG
1743 commands. These resets are often distinguishable from system
1744 resets, either explicitly (a "reset reason" register says so)
1745 or implicitly (not all parts of the chip get reset).
1747 @emph{Other Resets} ... system-on-chip devices often support
1748 several other types of reset.
1749 You may need to arrange that a watchdog timer stops
1750 while debugging, preventing a watchdog reset.
1751 There may be individual module resets.
1754 In the best case, OpenOCD can hold SRST, then reset
1755 the TAPs via TRST and send commands through JTAG to halt the
1756 CPU at the reset vector before the 1st instruction is executed.
1757 Then when it finally releases the SRST signal, the system is
1758 halted under debugger control before any code has executed.
1759 This is the behavior required to support the @command{reset halt}
1760 and @command{reset init} commands; after @command{reset init} a
1761 board-specific script might do things like setting up DRAM.
1762 (@xref{Reset Command}.)
1764 @section SRST and TRST Issues
1766 Because SRST and TRST are hardware signals, they can have a
1767 variety of system-specific constraints. Some of the most
1772 @item @emph{Signal not available} ... Some boards don't wire
1773 SRST or TRST to the JTAG connector. Some JTAG adapters don't
1774 support such signals even if they are wired up.
1775 Use the @command{reset_config} @var{signals} options to say
1776 when one of those signals is not connected.
1777 When SRST is not available, your code might not be able to rely
1778 on controllers having been fully reset during code startup.
1780 @item @emph{Signals shorted} ... Sometimes a chip, board, or
1781 adapter will connect SRST to TRST, instead of keeping them separate.
1782 Use the @command{reset_config} @var{combination} options to say
1783 when those signals aren't properly independent.
1785 @item @emph{Timing} ... Reset circuitry like a resistor/capacitor
1786 delay circuit, reset supervisor, or on-chip features can extend
1787 the effect of a JTAG adapter's reset for some time after the adapter
1788 stops issuing the reset. For example, there may be chip or board
1789 requirements that all reset pulses last for at least a
1790 certain amount of time; and reset buttons commonly have
1791 hardware debouncing.
1792 Use the @command{jtag_nsrst_delay} and @command{jtag_ntrst_delay}
1793 commands to say when extra delays are needed.
1795 @item @emph{Drive type} ... Reset lines often have a pullup
1796 resistor, letting the JTAG interface treat them as open-drain
1797 signals. But that's not a requirement, so the adapter may need
1798 to use push/pull output drivers.
1799 Also, with weak pullups it may be advisable to drive
1800 signals to both levels (push/pull) to minimize rise times.
1801 Use the @command{reset_config} @var{trst_type} and
1802 @var{srst_type} parameters to say how to drive reset signals.
1804 @item @emph{Special initialization} ... Targets sometimes need
1805 special JTAG initialization sequences to handle chip-specific
1806 issues (not limited to errata).
1807 For example, certain JTAG commands might need to be issued while
1808 the system as a whole is in a reset state (SRST active)
1809 but the JTAG scan chain is usable (TRST inactive).
1810 (@xref{JTAG Commands}, where the @command{jtag_reset}
1811 command is presented.)
1814 There can also be other issues.
1815 Some devices don't fully conform to the JTAG specifications.
1816 Trivial system-specific differences are common, such as
1817 SRST and TRST using slightly different names.
1818 There are also vendors who distribute key JTAG documentation for
1819 their chips only to developers who have signed a Non-Disclosure
1822 Sometimes there are chip-specific extensions like a requirement to use
1823 the normally-optional TRST signal (precluding use of JTAG adapters which
1824 don't pass TRST through), or needing extra steps to complete a TAP reset.
1826 In short, SRST and especially TRST handling may be very finicky,
1827 needing to cope with both architecture and board specific constraints.
1829 @section Commands for Handling Resets
1831 @deffn {Command} jtag_nsrst_delay milliseconds
1832 How long (in milliseconds) OpenOCD should wait after deasserting
1833 nSRST (active-low system reset) before starting new JTAG operations.
1834 When a board has a reset button connected to SRST line it will
1835 probably have hardware debouncing, implying you should use this.
1838 @deffn {Command} jtag_ntrst_delay milliseconds
1839 How long (in milliseconds) OpenOCD should wait after deasserting
1840 nTRST (active-low JTAG TAP reset) before starting new JTAG operations.
1843 @deffn {Command} reset_config mode_flag ...
1844 This command tells OpenOCD the reset configuration
1845 of your combination of JTAG board and target in target
1846 configuration scripts.
1848 If you have an interface that does not support SRST and
1849 TRST(unlikely), then you may be able to work around that
1850 problem by using a reset_config command to override any
1851 settings in the target configuration script.
1853 SRST and TRST has a fairly well understood definition and
1854 behaviour in the JTAG specification, but vendors take
1855 liberties to achieve various more or less clearly understood
1856 goals. Sometimes documentation is available, other times it
1857 is not. OpenOCD has the reset_config command to allow OpenOCD
1858 to deal with the various common cases.
1860 The @var{mode_flag} options can be specified in any order, but only one
1861 of each type -- @var{signals}, @var{combination}, @var{trst_type},
1862 and @var{srst_type} -- may be specified at a time.
1863 If you don't provide a new value for a given type, its previous
1864 value (perhaps the default) is unchanged.
1865 For example, this means that you don't need to say anything at all about
1866 TRST just to declare that if the JTAG adapter should want to drive SRST,
1867 it must explicitly be driven high (@option{srst_push_pull}).
1869 @var{signals} can specify which of the reset signals are connected.
1870 For example, If the JTAG interface provides SRST, but the board doesn't
1871 connect that signal properly, then OpenOCD can't use it.
1872 Possible values are @option{none} (the default), @option{trst_only},
1873 @option{srst_only} and @option{trst_and_srst}.
1876 If your board provides SRST or TRST through the JTAG connector,
1877 you must declare that or else those signals will not be used.
1880 The @var{combination} is an optional value specifying broken reset
1881 signal implementations.
1882 The default behaviour if no option given is @option{separate},
1883 indicating everything behaves normally.
1884 @option{srst_pulls_trst} states that the
1885 test logic is reset together with the reset of the system (e.g. Philips
1886 LPC2000, "broken" board layout), @option{trst_pulls_srst} says that
1887 the system is reset together with the test logic (only hypothetical, I
1888 haven't seen hardware with such a bug, and can be worked around).
1889 @option{combined} implies both @option{srst_pulls_trst} and
1890 @option{trst_pulls_srst}.
1892 The optional @var{trst_type} and @var{srst_type} parameters allow the
1893 driver mode of each reset line to be specified. These values only affect
1894 JTAG interfaces with support for different driver modes, like the Amontec
1895 JTAGkey and JTAGAccelerator. Also, they are necessarily ignored if the
1896 relevant signal (TRST or SRST) is not connected.
1898 Possible @var{trst_type} driver modes for the test reset signal (TRST)
1899 are @option{trst_push_pull} (default) and @option{trst_open_drain}.
1900 Most boards connect this signal to a pulldown, so the JTAG TAPs
1901 never leave reset unless they are hooked up to a JTAG adapter.
1903 Possible @var{srst_type} driver modes for the system reset signal (SRST)
1904 are the default @option{srst_open_drain}, and @option{srst_push_pull}.
1905 Most boards connect this signal to a pullup, and allow the
1906 signal to be pulled low by various events including system
1907 powerup and pressing a reset button.
1911 @node TAP Declaration
1912 @chapter TAP Declaration
1913 @cindex TAP declaration
1914 @cindex TAP configuration
1916 @emph{Test Access Ports} (TAPs) are the core of JTAG.
1917 TAPs serve many roles, including:
1920 @item @b{Debug Target} A CPU TAP can be used as a GDB debug target
1921 @item @b{Flash Programing} Some chips program the flash directly via JTAG.
1922 Others do it indirectly, making a CPU do it.
1923 @item @b{Program Download} Using the same CPU support GDB uses,
1924 you can initialize a DRAM controller, download code to DRAM, and then
1925 start running that code.
1926 @item @b{Boundary Scan} Most chips support boundary scan, which
1927 helps test for board assembly problems like solder bridges
1928 and missing connections
1931 OpenOCD must know about the active TAPs on your board(s).
1932 Setting up the TAPs is the core task of your configuration files.
1933 Once those TAPs are set up, you can pass their names to code
1934 which sets up CPUs and exports them as GDB targets,
1935 probes flash memory, performs low-level JTAG operations, and more.
1937 @section Scan Chains
1939 OpenOCD uses a JTAG adapter (interface) to talk to your board,
1940 which has a daisy chain of TAPs.
1941 That daisy chain is called a @dfn{scan chain}.
1942 Simple configurations may have a single TAP in the scan chain,
1943 perhaps for a microcontroller.
1944 Complex configurations might have a dozen or more TAPs:
1945 several in one chip, more in the next, and connecting
1946 to other boards with their own chips and TAPs.
1948 Unfortunately those TAPs can't always be autoconfigured,
1949 because not all devices provide good support for that.
1950 (JTAG doesn't require supporting IDCODE instructions.)
1951 The configuration mechanism currently supported by OpenOCD
1952 requires explicit configuration of all TAP devices using
1953 @command{jtag newtap} commands.
1954 One like this would declare a tap and name it @code{chip1.cpu}:
1957 jtag newtap chip1 cpu -irlen 7 -ircapture 0x01 -irmask 0x55
1960 Each target configuration file lists the TAPs provided
1962 Board configuration files combine all the targets on a board,
1964 Note that @emph{the order in which TAPs are declared is very important.}
1965 It must match the order in the JTAG scan chain, both inside
1966 a single chip and between them.
1967 @xref{FAQ TAP Order}.
1969 For example, the ST Microsystems STR912 chip has
1970 three separate TAPs@footnote{See the ST
1971 document titled: @emph{STR91xFAxxx, Section 3.15 Jtag Interface, Page:
1972 28/102, Figure 3: JTAG chaining inside the STR91xFA}.
1973 @url{http://eu.st.com/stonline/products/literature/ds/13495.pdf}}.
1974 To configure those taps, @file{target/str912.cfg}
1975 includes commands something like this:
1978 jtag newtap str912 flash ... params ...
1979 jtag newtap str912 cpu ... params ...
1980 jtag newtap str912 bs ... params ...
1983 Actual config files use a variable instead of literals like
1984 @option{str912}, to support more than one chip of each type.
1985 @xref{Config File Guidelines}.
1989 When TAP objects are declared with @command{jtag newtap},
1990 a @dfn{dotted.name} is created for the TAP, combining the
1991 name of a module (usually a chip) and a label for the TAP.
1992 For example: @code{xilinx.tap}, @code{str912.flash},
1993 @code{omap3530.jrc}, @code{dm6446.dsp}, or @code{stm32.cpu}.
1994 Many other commands use that dotted.name to manipulate or
1995 refer to the TAP. For example, CPU configuration uses the
1996 name, as does declaration of NAND or NOR flash banks.
1998 The components of a dotted name should follow ``C'' symbol
1999 name rules: start with an alphabetic character, then numbers
2000 and underscores are OK; while others (including dots!) are not.
2003 In older code, JTAG TAPs were numbered from 0..N.
2004 This feature is still present.
2005 However its use is highly discouraged, and
2006 should not be counted upon.
2007 Update all of your scripts to use TAP names rather than numbers.
2008 Using TAP numbers in target configuration scripts prevents
2009 reusing on boards with multiple targets.
2012 @section TAP Declaration Commands
2014 @c shouldn't this be(come) a {Config Command}?
2015 @anchor{jtag newtap}
2016 @deffn Command {jtag newtap} chipname tapname configparams...
2017 Declares a new TAP with the dotted name @var{chipname}.@var{tapname},
2018 and configured according to the various @var{configparams}.
2020 The @var{chipname} is a symbolic name for the chip.
2021 Conventionally target config files use @code{$_CHIPNAME},
2022 defaulting to the model name given by the chip vendor but
2025 @cindex TAP naming convention
2026 The @var{tapname} reflects the role of that TAP,
2027 and should follow this convention:
2030 @item @code{bs} -- For boundary scan if this is a seperate TAP;
2031 @item @code{cpu} -- The main CPU of the chip, alternatively
2032 @code{arm} and @code{dsp} on chips with both ARM and DSP CPUs,
2033 @code{arm1} and @code{arm2} on chips two ARMs, and so forth;
2034 @item @code{etb} -- For an embedded trace buffer (example: an ARM ETB11);
2035 @item @code{flash} -- If the chip has a flash TAP, like the str912;
2036 @item @code{jrc} -- For JTAG route controller (example: the ICEpick modules
2037 on many Texas Instruments chips, like the OMAP3530 on Beagleboards);
2038 @item @code{tap} -- Should be used only FPGA or CPLD like devices
2040 @item @code{unknownN} -- If you have no idea what the TAP is for (N is a number);
2041 @item @emph{when in doubt} -- Use the chip maker's name in their data sheet.
2042 For example, the Freescale IMX31 has a SDMA (Smart DMA) with
2043 a JTAG TAP; that TAP should be named @code{sdma}.
2046 Every TAP requires at least the following @var{configparams}:
2049 @item @code{-ircapture} @var{NUMBER}
2050 @*The IDCODE capture command, such as 0x01.
2051 @item @code{-irlen} @var{NUMBER}
2052 @*The length in bits of the
2053 instruction register, such as 4 or 5 bits.
2054 @item @code{-irmask} @var{NUMBER}
2055 @*A mask for the IR register.
2056 For some devices, there are bits in the IR that aren't used.
2057 This lets OpenOCD mask them off when doing IDCODE comparisons.
2058 In general, this should just be all ones for the size of the IR.
2061 A TAP may also provide optional @var{configparams}:
2064 @item @code{-disable} (or @code{-enable})
2065 @*Use the @code{-disable} paramater to flag a TAP which is not
2066 linked in to the scan chain when it is declared.
2067 You may use @code{-enable} to highlight the default state
2068 (the TAP is linked in).
2069 @xref{Enabling and Disabling TAPs}.
2070 @item @code{-expected-id} @var{number}
2071 @*A non-zero value represents the expected 32-bit IDCODE
2072 found when the JTAG chain is examined.
2073 These codes are not required by all JTAG devices.
2074 @emph{Repeat the option} as many times as required if more than one
2075 ID code could appear (for example, multiple versions).
2079 @c @deffn Command {jtag arp_init-reset}
2080 @c ... more or less "init" ?
2082 @anchor{Enabling and Disabling TAPs}
2083 @section Enabling and Disabling TAPs
2086 In some systems, a @dfn{JTAG Route Controller} (JRC)
2087 is used to enable and/or disable specific JTAG TAPs.
2088 Many ARM based chips from Texas Instruments include
2089 an ``ICEpick'' module, which is a JRC.
2090 Such chips include DaVinci and OMAP3 processors.
2092 A given TAP may not be visible until the JRC has been
2093 told to link it into the scan chain; and if the JRC
2094 has been told to unlink that TAP, it will no longer
2096 Such routers address problems that JTAG ``bypass mode''
2100 @item The scan chain can only go as fast as its slowest TAP.
2101 @item Having many TAPs slows instruction scans, since all
2102 TAPs receive new instructions.
2103 @item TAPs in the scan chain must be powered up, which wastes
2104 power and prevents debugging some power management mechanisms.
2107 The IEEE 1149.1 JTAG standard has no concept of a ``disabled'' tap,
2108 as implied by the existence of JTAG routers.
2109 However, the upcoming IEEE 1149.7 framework (layered on top of JTAG)
2110 does include a kind of JTAG router functionality.
2112 @c (a) currently the event handlers don't seem to be able to
2113 @c fail in a way that could lead to no-change-of-state.
2114 @c (b) eventually non-event configuration should be possible,
2115 @c in which case some this documentation must move.
2117 @deffn Command {jtag cget} dotted.name @option{-event} name
2118 @deffnx Command {jtag configure} dotted.name @option{-event} name string
2119 At this writing this mechanism is used only for event handling,
2120 and the only two events relate to TAP enabling and disabling.
2122 The @code{configure} subcommand assigns an event handler,
2123 a TCL string which is evaluated when the event is triggered.
2124 The @code{cget} subcommand returns that handler.
2125 The two possible values for an event @var{name}
2126 are @option{tap-disable} and @option{tap-enable}.
2128 So for example, when defining a TAP for a CPU connected to
2129 a JTAG router, you should define TAP event handlers using
2130 code that looks something like this:
2133 jtag configure CHIP.cpu -event tap-enable @{
2134 echo "Enabling CPU TAP"
2135 ... jtag operations using CHIP.jrc
2137 jtag configure CHIP.cpu -event tap-disable @{
2138 echo "Disabling CPU TAP"
2139 ... jtag operations using CHIP.jrc
2144 @deffn Command {jtag tapdisable} dotted.name
2145 @deffnx Command {jtag tapenable} dotted.name
2146 @deffnx Command {jtag tapisenabled} dotted.name
2147 These three commands all return the string "1" if the tap
2148 specified by @var{dotted.name} is enabled,
2149 and "0" if it is disbabled.
2150 The @command{tapenable} variant first enables the tap
2151 by sending it a @option{tap-enable} event.
2152 The @command{tapdisable} variant first disables the tap
2153 by sending it a @option{tap-disable} event.
2156 Humans will find the @command{scan_chain} command more helpful
2157 than the script-oriented @command{tapisenabled}
2158 for querying the state of the JTAG taps.
2162 @node CPU Configuration
2163 @chapter CPU Configuration
2166 This chapter discusses how to set up GDB debug targets for CPUs.
2167 You can also access these targets without GDB
2168 (@pxref{Architecture and Core Commands},
2169 and @ref{Target State handling}) and
2170 through various kinds of NAND and NOR flash commands.
2171 If you have multiple CPUs you can have multiple such targets.
2173 We'll start by looking at how to examine the targets you have,
2174 then look at how to add one more target and how to configure it.
2176 @section Target List
2178 All targets that have been set up are part of a list,
2179 where each member has a name.
2180 That name should normally be the same as the TAP name.
2181 You can display the list with the @command{targets}
2183 This display often has only one CPU; here's what it might
2184 look like with more than one:
2186 TargetName Type Endian TapName State
2187 -- ------------------ ---------- ------ ------------------ ------------
2188 0* at91rm9200.cpu arm920t little at91rm9200.cpu running
2189 1 MyTarget cortex_m3 little mychip.foo tap-disabled
2192 One member of that list is the @dfn{current target}, which
2193 is implicitly referenced by many commands.
2194 It's the one marked with a @code{*} near the target name.
2195 In particular, memory addresses often refer to the address
2196 space seen by that current target.
2197 Commands like @command{mdw} (memory display words)
2198 and @command{flash erase_address} (erase NOR flash blocks)
2199 are examples; and there are many more.
2201 Several commands let you examine the list of targets:
2203 @deffn Command {target count}
2204 Returns the number of targets, @math{N}.
2205 The highest numbered target is @math{N - 1}.
2207 set c [target count]
2208 for @{ set x 0 @} @{ $x < $c @} @{ incr x @} @{
2209 # Assuming you have created this function
2210 print_target_details $x
2215 @deffn Command {target current}
2216 Returns the name of the current target.
2219 @deffn Command {target names}
2220 Lists the names of all current targets in the list.
2222 foreach t [target names] @{
2223 puts [format "Target: %s\n" $t]
2228 @deffn Command {target number} number
2229 The list of targets is numbered starting at zero.
2230 This command returns the name of the target at index @var{number}.
2232 set thename [target number $x]
2233 puts [format "Target %d is: %s\n" $x $thename]
2237 @c yep, "target list" would have been better.
2238 @c plus maybe "target setdefault".
2240 @deffn Command targets [name]
2241 @emph{Note: the name of this command is plural. Other target
2242 command names are singular.}
2244 With no parameter, this command displays a table of all known
2245 targets in a user friendly form.
2247 With a parameter, this command sets the current target to
2248 the given target with the given @var{name}; this is
2249 only relevant on boards which have more than one target.
2252 @section Target CPU Types and Variants
2254 Each target has a @dfn{CPU type}, as shown in the output of
2255 the @command{targets} command. You need to specify that type
2256 when calling @command{target create}.
2257 The CPU type indicates more than just the instruction set.
2258 It also indicates how that instruction set is implemented,
2259 what kind of debug support it integrates,
2260 whether it has an MMU (and if so, what kind),
2261 what core-specific commands may be available
2262 (@pxref{Architecture and Core Commands}),
2265 For some CPU types, OpenOCD also defines @dfn{variants} which
2266 indicate differences that affect their handling.
2267 For example, a particular implementation bug might need to be
2268 worked around in some chip versions.
2270 It's easy to see what target types are supported,
2271 since there's a command to list them.
2272 However, there is currently no way to list what target variants
2273 are supported (other than by reading the OpenOCD source code).
2275 @anchor{target types}
2276 @deffn Command {target types}
2277 Lists all supported target types.
2278 At this writing, the supported CPU types and variants are:
2281 @item @code{arm11} -- this is a generation of ARMv6 cores
2282 @item @code{arm720t} -- this is an ARMv4 core
2283 @item @code{arm7tdmi} -- this is an ARMv4 core
2284 @item @code{arm920t} -- this is an ARMv5 core
2285 @item @code{arm926ejs} -- this is an ARMv5 core
2286 @item @code{arm966e} -- this is an ARMv5 core
2287 @item @code{arm9tdmi} -- this is an ARMv4 core
2288 @item @code{avr} -- implements Atmel's 8-bit AVR instruction set.
2289 (Support for this is preliminary and incomplete.)
2290 @item @code{cortex_a8} -- this is an ARMv7 core
2291 @item @code{cortex_m3} -- this is an ARMv7 core, supporting only the
2292 compact Thumb2 instruction set. It supports one variant:
2294 @item @code{lm3s} ... Use this when debugging older Stellaris LM3S targets.
2295 This will cause OpenOCD to use a software reset rather than asserting
2296 SRST, to avoid a issue with clearing the debug registers.
2297 This is fixed in Fury Rev B, DustDevil Rev B, Tempest; these revisions will
2298 be detected and the normal reset behaviour used.
2300 @item @code{feroceon} -- resembles arm926
2301 @item @code{mips_m4k} -- a MIPS core. This supports one variant:
2303 @item @code{ejtag_srst} ... Use this when debugging targets that do not
2304 provide a functional SRST line on the EJTAG connector. This causes
2305 OpenOCD to instead use an EJTAG software reset command to reset the
2307 You still need to enable @option{srst} on the @command{reset_config}
2308 command to enable OpenOCD hardware reset functionality.
2310 @item @code{xscale} -- this is actually an architecture,
2311 not a CPU type. It is based on the ARMv5 architecture.
2312 There are several variants defined:
2314 @item @code{ixp42x}, @code{ixp45x}, @code{ixp46x},
2315 @code{pxa27x} ... instruction register length is 7 bits
2316 @item @code{pxa250}, @code{pxa255},
2317 @code{pxa26x} ... instruction register length is 5 bits
2322 To avoid being confused by the variety of ARM based cores, remember
2323 this key point: @emph{ARM is a technology licencing company}.
2324 (See: @url{http://www.arm.com}.)
2325 The CPU name used by OpenOCD will reflect the CPU design that was
2326 licenced, not a vendor brand which incorporates that design.
2327 Name prefixes like arm7, arm9, arm11, and cortex
2328 reflect design generations;
2329 while names like ARMv4, ARMv5, ARMv6, and ARMv7
2330 reflect an architecture version implemented by a CPU design.
2332 @anchor{Target Configuration}
2333 @section Target Configuration
2335 Before creating a ``target'', you must have added its TAP to the scan chain.
2336 When you've added that TAP, you will have a @code{dotted.name}
2337 which is used to set up the CPU support.
2338 The chip-specific configuration file will normally configure its CPU(s)
2339 right after it adds all of the chip's TAPs to the scan chain.
2341 Although you can set up a target in one step, it's often clearer if you
2342 use shorter commands and do it in two steps: create it, then configure
2344 All operations on the target after it's created will use a new
2345 command, created as part of target creation.
2347 The two main things to configure after target creation are
2348 a work area, which usually has target-specific defaults even
2349 if the board setup code overrides them later;
2350 and event handlers (@pxref{Target Events}), which tend
2351 to be much more board-specific.
2352 The key steps you use might look something like this
2355 target create MyTarget cortex_m3 -chain-position mychip.cpu
2356 $MyTarget configure -work-area-phys 0x08000 -work-area-size 8096
2357 $MyTarget configure -event reset-deassert-pre @{ jtag_rclk 5 @}
2358 $MyTarget configure -event reset-init @{ myboard_reinit @}
2361 You should specify a working area if you can; typically it uses some
2363 Such a working area can speed up many things, including bulk
2364 writes to target memory;
2365 flash operations like checking to see if memory needs to be erased;
2366 GDB memory checksumming;
2370 On more complex chips, the work area can become
2371 inaccessible when application code
2372 (such as an operating system)
2373 enables or disables the MMU.
2374 For example, the particular MMU context used to acess the virtual
2375 address will probably matter ... and that context might not have
2376 easy access to other addresses needed.
2377 At this writing, OpenOCD doesn't have much MMU intelligence.
2380 It's often very useful to define a @code{reset-init} event handler.
2381 For systems that are normally used with a boot loader,
2382 common tasks include updating clocks and initializing memory
2384 That may be needed to let you write the boot loader into flash,
2385 in order to ``de-brick'' your board; or to load programs into
2386 external DDR memory without having run the boot loader.
2388 @deffn Command {target create} target_name type configparams...
2389 This command creates a GDB debug target that refers to a specific JTAG tap.
2390 It enters that target into a list, and creates a new
2391 command (@command{@var{target_name}}) which is used for various
2392 purposes including additional configuration.
2395 @item @var{target_name} ... is the name of the debug target.
2396 By convention this should be the same as the @emph{dotted.name}
2397 of the TAP associated with this target, which must be specified here
2398 using the @code{-chain-position @var{dotted.name}} configparam.
2400 This name is also used to create the target object command,
2401 referred to here as @command{$target_name},
2402 and in other places the target needs to be identified.
2403 @item @var{type} ... specifies the target type. @xref{target types}.
2404 @item @var{configparams} ... all parameters accepted by
2405 @command{$target_name configure} are permitted.
2406 If the target is big-endian, set it here with @code{-endian big}.
2407 If the variant matters, set it here with @code{-variant}.
2409 You @emph{must} set the @code{-chain-position @var{dotted.name}} here.
2413 @deffn Command {$target_name configure} configparams...
2414 The options accepted by this command may also be
2415 specified as parameters to @command{target create}.
2416 Their values can later be queried one at a time by
2417 using the @command{$target_name cget} command.
2419 @emph{Warning:} changing some of these after setup is dangerous.
2420 For example, moving a target from one TAP to another;
2421 and changing its endianness or variant.
2425 @item @code{-chain-position} @var{dotted.name} -- names the TAP
2426 used to access this target.
2428 @item @code{-endian} (@option{big}|@option{little}) -- specifies
2429 whether the CPU uses big or little endian conventions
2431 @item @code{-event} @var{event_name} @var{event_body} --
2432 @xref{Target Events}.
2433 Note that this updates a list of named event handlers.
2434 Calling this twice with two different event names assigns
2435 two different handlers, but calling it twice with the
2436 same event name assigns only one handler.
2438 @item @code{-variant} @var{name} -- specifies a variant of the target,
2439 which OpenOCD needs to know about.
2441 @item @code{-work-area-backup} (@option{0}|@option{1}) -- says
2442 whether the work area gets backed up; by default, it doesn't.
2443 When possible, use a working_area that doesn't need to be backed up,
2444 since performing a backup slows down operations.
2446 @item @code{-work-area-size} @var{size} -- specify/set the work area
2448 @item @code{-work-area-phys} @var{address} -- set the work area
2449 base @var{address} to be used when no MMU is active.
2451 @item @code{-work-area-virt} @var{address} -- set the work area
2452 base @var{address} to be used when an MMU is active.
2457 @section Other $target_name Commands
2458 @cindex object command
2460 The Tcl/Tk language has the concept of object commands,
2461 and OpenOCD adopts that same model for targets.
2463 A good Tk example is a on screen button.
2464 Once a button is created a button
2465 has a name (a path in Tk terms) and that name is useable as a first
2466 class command. For example in Tk, one can create a button and later
2467 configure it like this:
2471 button .foobar -background red -command @{ foo @}
2473 .foobar configure -foreground blue
2475 set x [.foobar cget -background]
2477 puts [format "The button is %s" $x]
2480 In OpenOCD's terms, the ``target'' is an object just like a Tcl/Tk
2481 button, and its object commands are invoked the same way.
2484 str912.cpu mww 0x1234 0x42
2485 omap3530.cpu mww 0x5555 123
2488 The commands supported by OpenOCD target objects are:
2490 @deffn Command {$target_name arp_examine}
2491 @deffnx Command {$target_name arp_halt}
2492 @deffnx Command {$target_name arp_poll}
2493 @deffnx Command {$target_name arp_reset}
2494 @deffnx Command {$target_name arp_waitstate}
2495 Internal OpenOCD scripts (most notably @file{startup.tcl})
2496 use these to deal with specific reset cases.
2497 They are not otherwise documented here.
2500 @deffn Command {$target_name array2mem} arrayname width address count
2501 @deffnx Command {$target_name mem2array} arrayname width address count
2502 These provide an efficient script-oriented interface to memory.
2503 The @code{array2mem} primitive writes bytes, halfwords, or words;
2504 while @code{mem2array} reads them.
2505 In both cases, the TCL side uses an array, and
2506 the target side uses raw memory.
2508 The efficiency comes from enabling the use of
2509 bulk JTAG data transfer operations.
2510 The script orientation comes from working with data
2511 values that are packaged for use by TCL scripts;
2512 @command{mdw} type primitives only print data they retrieve,
2513 and neither store nor return those values.
2516 @item @var{arrayname} ... is the name of an array variable
2517 @item @var{width} ... is 8/16/32 - indicating the memory access size
2518 @item @var{address} ... is the target memory address
2519 @item @var{count} ... is the number of elements to process
2523 @deffn Command {$target_name cget} queryparm
2524 Each configuration parameter accepted by
2525 @command{$target_name configure}
2526 can be individually queried, to return its current value.
2527 The @var{queryparm} is a parameter name
2528 accepted by that command, such as @code{-work-area-phys}.
2529 There are a few special cases:
2532 @item @code{-event} @var{event_name} -- returns the handler for the
2533 event named @var{event_name}.
2534 This is a special case because setting a handler requires
2536 @item @code{-type} -- returns the target type.
2537 This is a special case because this is set using
2538 @command{target create} and can't be changed
2539 using @command{$target_name configure}.
2542 For example, if you wanted to summarize information about
2543 all the targets you might use something like this:
2546 for @{ set x 0 @} @{ $x < [target count] @} @{ incr x @} @{
2547 set name [target number $x]
2548 set y [$name cget -endian]
2549 set z [$name cget -type]
2550 puts [format "Chip %d is %s, Endian: %s, type: %s" \
2556 @anchor{target curstate}
2557 @deffn Command {$target_name curstate}
2558 Displays the current target state:
2559 @code{debug-running},
2562 @code{running}, or @code{unknown}.
2563 (Also, @pxref{Event Polling}.)
2566 @deffn Command {$target_name eventlist}
2567 Displays a table listing all event handlers
2568 currently associated with this target.
2569 @xref{Target Events}.
2572 @deffn Command {$target_name invoke-event} event_name
2573 Invokes the handler for the event named @var{event_name}.
2574 (This is primarily intended for use by OpenOCD framework
2575 code, for example by the reset code in @file{startup.tcl}.)
2578 @deffn Command {$target_name mdw} addr [count]
2579 @deffnx Command {$target_name mdh} addr [count]
2580 @deffnx Command {$target_name mdb} addr [count]
2581 Display contents of address @var{addr}, as
2582 32-bit words (@command{mdw}), 16-bit halfwords (@command{mdh}),
2583 or 8-bit bytes (@command{mdb}).
2584 If @var{count} is specified, displays that many units.
2585 (If you want to manipulate the data instead of displaying it,
2586 see the @code{mem2array} primitives.)
2589 @deffn Command {$target_name mww} addr word
2590 @deffnx Command {$target_name mwh} addr halfword
2591 @deffnx Command {$target_name mwb} addr byte
2592 Writes the specified @var{word} (32 bits),
2593 @var{halfword} (16 bits), or @var{byte} (8-bit) pattern,
2594 at the specified address @var{addr}.
2597 @anchor{Target Events}
2598 @section Target Events
2600 At various times, certain things can happen, or you want them to happen.
2603 @item What should happen when GDB connects? Should your target reset?
2604 @item When GDB tries to flash the target, do you need to enable the flash via a special command?
2605 @item During reset, do you need to write to certain memory locations
2606 to set up system clocks or
2607 to reconfigure the SDRAM?
2610 All of the above items can be addressed by target event handlers.
2611 These are set up by @command{$target_name configure -event} or
2612 @command{target create ... -event}.
2614 The programmer's model matches the @code{-command} option used in Tcl/Tk
2615 buttons and events. The two examples below act the same, but one creates
2616 and invokes a small procedure while the other inlines it.
2619 proc my_attach_proc @{ @} @{
2623 mychip.cpu configure -event gdb-attach my_attach_proc
2624 mychip.cpu configure -event gdb-attach @{
2630 The following target events are defined:
2633 @item @b{debug-halted}
2634 @* The target has halted for debug reasons (i.e.: breakpoint)
2635 @item @b{debug-resumed}
2636 @* The target has resumed (i.e.: gdb said run)
2637 @item @b{early-halted}
2638 @* Occurs early in the halt process
2639 @item @b{examine-end}
2640 @* Currently not used (goal: when JTAG examine completes)
2641 @item @b{examine-start}
2642 @* Currently not used (goal: when JTAG examine starts)
2643 @item @b{gdb-attach}
2644 @* When GDB connects
2645 @item @b{gdb-detach}
2646 @* When GDB disconnects
2648 @* When the taret has halted and GDB is not doing anything (see early halt)
2649 @item @b{gdb-flash-erase-start}
2650 @* Before the GDB flash process tries to erase the flash
2651 @item @b{gdb-flash-erase-end}
2652 @* After the GDB flash process has finished erasing the flash
2653 @item @b{gdb-flash-write-start}
2654 @* Before GDB writes to the flash
2655 @item @b{gdb-flash-write-end}
2656 @* After GDB writes to the flash
2658 @* Before the taret steps, gdb is trying to start/resume the target
2660 @* The target has halted
2661 @item @b{old-gdb_program_config}
2662 @* DO NOT USE THIS: Used internally
2663 @item @b{old-pre_resume}
2664 @* DO NOT USE THIS: Used internally
2665 @item @b{reset-assert-pre}
2666 @* Issued as part of @command{reset} processing
2667 after SRST and/or TRST were activated and deactivated,
2668 but before reset is asserted on the tap.
2669 @item @b{reset-assert-post}
2670 @* Issued as part of @command{reset} processing
2671 when reset is asserted on the tap.
2672 @item @b{reset-deassert-pre}
2673 @* Issued as part of @command{reset} processing
2674 when reset is about to be released on the tap.
2676 For some chips, this may be a good place to make sure
2677 the JTAG clock is slow enough to work before the PLL
2678 has been set up to allow faster JTAG speeds.
2679 @item @b{reset-deassert-post}
2680 @* Issued as part of @command{reset} processing
2681 when reset has been released on the tap.
2683 @* Issued as the final step in @command{reset} processing.
2684 @item @b{reset-halt-post}
2685 @* Currently not usd
2686 @item @b{reset-halt-pre}
2687 @* Currently not used
2688 @item @b{reset-init}
2689 @* Used by @b{reset init} command for board-specific initialization.
2690 This event fires after @emph{reset-deassert-post}.
2692 This is where you would configure PLLs and clocking, set up DRAM so
2693 you can download programs that don't fit in on-chip SRAM, set up pin
2694 multiplexing, and so on.
2695 @item @b{reset-start}
2696 @* Issued as part of @command{reset} processing
2697 before either SRST or TRST are activated.
2698 @item @b{reset-wait-pos}
2699 @* Currently not used
2700 @item @b{reset-wait-pre}
2701 @* Currently not used
2702 @item @b{resume-start}
2703 @* Before any target is resumed
2704 @item @b{resume-end}
2705 @* After all targets have resumed
2709 @* Target has resumed
2713 @node Flash Commands
2714 @chapter Flash Commands
2716 OpenOCD has different commands for NOR and NAND flash;
2717 the ``flash'' command works with NOR flash, while
2718 the ``nand'' command works with NAND flash.
2719 This partially reflects different hardware technologies:
2720 NOR flash usually supports direct CPU instruction and data bus access,
2721 while data from a NAND flash must be copied to memory before it can be
2722 used. (SPI flash must also be copied to memory before use.)
2723 However, the documentation also uses ``flash'' as a generic term;
2724 for example, ``Put flash configuration in board-specific files''.
2727 As of 28-nov-2008 OpenOCD does not know how to program a SPI
2728 flash that a micro may boot from. Perhaps you, the reader, would like to
2729 contribute support for this.
2734 @item Configure via the command @command{flash bank}
2735 @* Do this in a board-specific configuration file,
2736 passing parameters as needed by the driver.
2737 @item Operate on the flash via @command{flash subcommand}
2738 @* Often commands to manipulate the flash are typed by a human, or run
2739 via a script in some automated way. Common tasks include writing a
2740 boot loader, operating system, or other data.
2742 @* Flashing via GDB requires the flash be configured via ``flash
2743 bank'', and the GDB flash features be enabled.
2744 @xref{GDB Configuration}.
2747 Many CPUs have the ablity to ``boot'' from the first flash bank.
2748 This means that misprograming that bank can ``brick'' a system,
2749 so that it can't boot.
2750 JTAG tools, like OpenOCD, are often then used to ``de-brick'' the
2751 board by (re)installing working boot firmware.
2753 @section Flash Configuration Commands
2754 @cindex flash configuration
2756 @deffn {Config Command} {flash bank} driver base size chip_width bus_width target [driver_options]
2757 Configures a flash bank which provides persistent storage
2758 for addresses from @math{base} to @math{base + size - 1}.
2759 These banks will often be visible to GDB through the target's memory map.
2760 In some cases, configuring a flash bank will activate extra commands;
2761 see the driver-specific documentation.
2764 @item @var{driver} ... identifies the controller driver
2765 associated with the flash bank being declared.
2766 This is usually @code{cfi} for external flash, or else
2767 the name of a microcontroller with embedded flash memory.
2768 @xref{Flash Driver List}.
2769 @item @var{base} ... Base address of the flash chip.
2770 @item @var{size} ... Size of the chip, in bytes.
2771 For some drivers, this value is detected from the hardware.
2772 @item @var{chip_width} ... Width of the flash chip, in bytes;
2773 ignored for most microcontroller drivers.
2774 @item @var{bus_width} ... Width of the data bus used to access the
2775 chip, in bytes; ignored for most microcontroller drivers.
2776 @item @var{target} ... Names the target used to issue
2777 commands to the flash controller.
2778 @comment Actually, it's currently a controller-specific parameter...
2779 @item @var{driver_options} ... drivers may support, or require,
2780 additional parameters. See the driver-specific documentation
2781 for more information.
2784 This command is not available after OpenOCD initialization has completed.
2785 Use it in board specific configuration files, not interactively.
2789 @comment the REAL name for this command is "ocd_flash_banks"
2790 @comment less confusing would be: "flash list" (like "nand list")
2791 @deffn Command {flash banks}
2792 Prints a one-line summary of each device declared
2793 using @command{flash bank}, numbered from zero.
2794 Note that this is the @emph{plural} form;
2795 the @emph{singular} form is a very different command.
2798 @deffn Command {flash probe} num
2799 Identify the flash, or validate the parameters of the configured flash. Operation
2800 depends on the flash type.
2801 The @var{num} parameter is a value shown by @command{flash banks}.
2802 Most flash commands will implicitly @emph{autoprobe} the bank;
2803 flash drivers can distinguish between probing and autoprobing,
2804 but most don't bother.
2807 @section Erasing, Reading, Writing to Flash
2808 @cindex flash erasing
2809 @cindex flash reading
2810 @cindex flash writing
2811 @cindex flash programming
2813 One feature distinguishing NOR flash from NAND or serial flash technologies
2814 is that for read access, it acts exactly like any other addressible memory.
2815 This means you can use normal memory read commands like @command{mdw} or
2816 @command{dump_image} with it, with no special @command{flash} subcommands.
2817 @xref{Memory access}, and @ref{Image access}.
2819 Write access works differently. Flash memory normally needs to be erased
2820 before it's written. Erasing a sector turns all of its bits to ones, and
2821 writing can turn ones into zeroes. This is why there are special commands
2822 for interactive erasing and writing, and why GDB needs to know which parts
2823 of the address space hold NOR flash memory.
2826 Most of these erase and write commands leverage the fact that NOR flash
2827 chips consume target address space. They implicitly refer to the current
2828 JTAG target, and map from an address in that target's address space
2829 back to a flash bank.
2830 @comment In May 2009, those mappings may fail if any bank associated
2831 @comment with that target doesn't succesfuly autoprobe ... bug worth fixing?
2832 A few commands use abstract addressing based on bank and sector numbers,
2833 and don't depend on searching the current target and its address space.
2834 Avoid confusing the two command models.
2837 Some flash chips implement software protection against accidental writes,
2838 since such buggy writes could in some cases ``brick'' a system.
2839 For such systems, erasing and writing may require sector protection to be
2841 Examples include CFI flash such as ``Intel Advanced Bootblock flash'',
2842 and AT91SAM7 on-chip flash.
2843 @xref{flash protect}.
2845 @anchor{flash erase_sector}
2846 @deffn Command {flash erase_sector} num first last
2847 Erase sectors in bank @var{num}, starting at sector @var{first} up to and including
2848 @var{last}. Sector numbering starts at 0.
2849 The @var{num} parameter is a value shown by @command{flash banks}.
2852 @deffn Command {flash erase_address} address length
2853 Erase sectors starting at @var{address} for @var{length} bytes.
2854 The flash bank to use is inferred from the @var{address}, and
2855 the specified length must stay within that bank.
2856 As a special case, when @var{length} is zero and @var{address} is
2857 the start of the bank, the whole flash is erased.
2860 @deffn Command {flash fillw} address word length
2861 @deffnx Command {flash fillh} address halfword length
2862 @deffnx Command {flash fillb} address byte length
2863 Fills flash memory with the specified @var{word} (32 bits),
2864 @var{halfword} (16 bits), or @var{byte} (8-bit) pattern,
2865 starting at @var{address} and continuing
2866 for @var{length} units (word/halfword/byte).
2867 No erasure is done before writing; when needed, that must be done
2868 before issuing this command.
2869 Writes are done in blocks of up to 1024 bytes, and each write is
2870 verified by reading back the data and comparing it to what was written.
2871 The flash bank to use is inferred from the @var{address} of
2872 each block, and the specified length must stay within that bank.
2874 @comment no current checks for errors if fill blocks touch multiple banks!
2876 @anchor{flash write_bank}
2877 @deffn Command {flash write_bank} num filename offset
2878 Write the binary @file{filename} to flash bank @var{num},
2879 starting at @var{offset} bytes from the beginning of the bank.
2880 The @var{num} parameter is a value shown by @command{flash banks}.
2883 @anchor{flash write_image}
2884 @deffn Command {flash write_image} [erase] filename [offset] [type]
2885 Write the image @file{filename} to the current target's flash bank(s).
2886 A relocation @var{offset} may be specified, in which case it is added
2887 to the base address for each section in the image.
2888 The file [@var{type}] can be specified
2889 explicitly as @option{bin} (binary), @option{ihex} (Intel hex),
2890 @option{elf} (ELF file), @option{s19} (Motorola s19).
2891 @option{mem}, or @option{builder}.
2892 The relevant flash sectors will be erased prior to programming
2893 if the @option{erase} parameter is given.
2894 The flash bank to use is inferred from the @var{address} of
2898 @section Other Flash commands
2899 @cindex flash protection
2901 @deffn Command {flash erase_check} num
2902 Check erase state of sectors in flash bank @var{num},
2903 and display that status.
2904 The @var{num} parameter is a value shown by @command{flash banks}.
2905 This is the only operation that
2906 updates the erase state information displayed by @option{flash info}. That means you have
2907 to issue an @command{flash erase_check} command after erasing or programming the device
2908 to get updated information.
2909 (Code execution may have invalidated any state records kept by OpenOCD.)
2912 @deffn Command {flash info} num
2913 Print info about flash bank @var{num}
2914 The @var{num} parameter is a value shown by @command{flash banks}.
2915 The information includes per-sector protect status.
2918 @anchor{flash protect}
2919 @deffn Command {flash protect} num first last (on|off)
2920 Enable (@var{on}) or disable (@var{off}) protection of flash sectors
2921 @var{first} to @var{last} of flash bank @var{num}.
2922 The @var{num} parameter is a value shown by @command{flash banks}.
2925 @deffn Command {flash protect_check} num
2926 Check protection state of sectors in flash bank @var{num}.
2927 The @var{num} parameter is a value shown by @command{flash banks}.
2928 @comment @option{flash erase_sector} using the same syntax.
2931 @anchor{Flash Driver List}
2932 @section Flash Drivers, Options, and Commands
2933 As noted above, the @command{flash bank} command requires a driver name,
2934 and allows driver-specific options and behaviors.
2935 Some drivers also activate driver-specific commands.
2937 @subsection External Flash
2939 @deffn {Flash Driver} cfi
2940 @cindex Common Flash Interface
2942 The ``Common Flash Interface'' (CFI) is the main standard for
2943 external NOR flash chips, each of which connects to a
2944 specific external chip select on the CPU.
2945 Frequently the first such chip is used to boot the system.
2946 Your board's @code{reset-init} handler might need to
2947 configure additional chip selects using other commands (like: @command{mww} to
2948 configure a bus and its timings) , or
2949 perhaps configure a GPIO pin that controls the ``write protect'' pin
2951 The CFI driver can use a target-specific working area to significantly
2954 The CFI driver can accept the following optional parameters, in any order:
2957 @item @var{jedec_probe} ... is used to detect certain non-CFI flash ROMs,
2958 like AM29LV010 and similar types.
2959 @item @var{x16_as_x8} ... when a 16-bit flash is hooked up to an 8-bit bus.
2962 To configure two adjacent banks of 16 MBytes each, both sixteen bits (two bytes)
2963 wide on a sixteen bit bus:
2966 flash bank cfi 0x00000000 0x01000000 2 2 $_TARGETNAME
2967 flash bank cfi 0x01000000 0x01000000 2 2 $_TARGETNAME
2971 @subsection Internal Flash (Microcontrollers)
2973 @deffn {Flash Driver} aduc702x
2974 The ADUC702x analog microcontrollers from ST Micro
2975 include internal flash and use ARM7TDMI cores.
2976 The aduc702x flash driver works with models ADUC7019 through ADUC7028.
2977 The setup command only requires the @var{target} argument
2978 since all devices in this family have the same memory layout.
2981 flash bank aduc702x 0 0 0 0 $_TARGETNAME
2985 @deffn {Flash Driver} at91sam7
2986 All members of the AT91SAM7 microcontroller family from Atmel
2987 include internal flash and use ARM7TDMI cores.
2988 The driver automatically recognizes a number of these chips using
2989 the chip identification register, and autoconfigures itself.
2992 flash bank at91sam7 0 0 0 0 $_TARGETNAME
2995 For chips which are not recognized by the controller driver, you must
2996 provide additional parameters in the following order:
2999 @item @var{chip_model} ... label used with @command{flash info}
3001 @item @var{sectors_per_bank}
3002 @item @var{pages_per_sector}
3003 @item @var{pages_size}
3004 @item @var{num_nvm_bits}
3005 @item @var{freq_khz} ... required if an external clock is provided,
3006 optional (but recommended) when the oscillator frequency is known
3009 It is recommended that you provide zeroes for all of those values
3010 except the clock frequency, so that everything except that frequency
3011 will be autoconfigured.
3012 Knowing the frequency helps ensure correct timings for flash access.
3014 The flash controller handles erases automatically on a page (128/256 byte)
3015 basis, so explicit erase commands are not necessary for flash programming.
3016 However, there is an ``EraseAll`` command that can erase an entire flash
3017 plane (of up to 256KB), and it will be used automatically when you issue
3018 @command{flash erase_sector} or @command{flash erase_address} commands.
3020 @deffn Command {at91sam7 gpnvm} bitnum (set|clear)
3021 Set or clear a ``General Purpose Non-Volatle Memory'' (GPNVM)
3022 bit for the processor. Each processor has a number of such bits,
3023 used for controlling features such as brownout detection (so they
3024 are not truly general purpose).
3026 This assumes that the first flash bank (number 0) is associated with
3027 the appropriate at91sam7 target.
3032 @deffn {Flash Driver} avr
3033 The AVR 8-bit microcontrollers from Atmel integrate flash memory.
3034 @emph{The current implementation is incomplete.}
3035 @comment - defines mass_erase ... pointless given flash_erase_address
3038 @deffn {Flash Driver} ecosflash
3039 @emph{No idea what this is...}
3040 The @var{ecosflash} driver defines one mandatory parameter,
3041 the name of a modules of target code which is downloaded
3045 @deffn {Flash Driver} lpc2000
3046 Most members of the LPC2000 microcontroller family from NXP
3047 include internal flash and use ARM7TDMI cores.
3048 The @var{lpc2000} driver defines two mandatory and one optional parameters,
3049 which must appear in the following order:
3052 @item @var{variant} ... required, may be
3053 @var{lpc2000_v1} (older LPC21xx and LPC22xx)
3054 or @var{lpc2000_v2} (LPC213x, LPC214x, LPC210[123], LPC23xx and LPC24xx)
3055 @item @var{clock_kHz} ... the frequency, in kiloHertz,
3056 at which the core is running
3057 @item @var{calc_checksum} ... optional (but you probably want to provide this!),
3058 telling the driver to calculate a valid checksum for the exception vector table.
3061 LPC flashes don't require the chip and bus width to be specified.
3064 flash bank lpc2000 0x0 0x7d000 0 0 $_TARGETNAME \
3065 lpc2000_v2 14765 calc_checksum
3069 @deffn {Flash Driver} lpc288x
3070 The LPC2888 microcontroller from NXP needs slightly different flash
3071 support from its lpc2000 siblings.
3072 The @var{lpc288x} driver defines one mandatory parameter,
3073 the programming clock rate in Hz.
3074 LPC flashes don't require the chip and bus width to be specified.
3077 flash bank lpc288x 0 0 0 0 $_TARGETNAME 12000000
3081 @deffn {Flash Driver} ocl
3082 @emph{No idea what this is, other than using some arm7/arm9 core.}
3085 flash bank ocl 0 0 0 0 $_TARGETNAME
3089 @deffn {Flash Driver} pic32mx
3090 The PIC32MX microcontrollers are based on the MIPS 4K cores,
3091 and integrate flash memory.
3092 @emph{The current implementation is incomplete.}
3095 flash bank pix32mx 0 0 0 0 $_TARGETNAME
3098 @comment numerous *disabled* commands are defined:
3099 @comment - chip_erase ... pointless given flash_erase_address
3100 @comment - lock, unlock ... pointless given protect on/off (yes?)
3101 @comment - pgm_word ... shouldn't bank be deduced from address??
3102 Some pic32mx-specific commands are defined:
3103 @deffn Command {pic32mx pgm_word} address value bank
3104 Programs the specified 32-bit @var{value} at the given @var{address}
3105 in the specified chip @var{bank}.
3109 @deffn {Flash Driver} stellaris
3110 All members of the Stellaris LM3Sxxx microcontroller family from
3112 include internal flash and use ARM Cortex M3 cores.
3113 The driver automatically recognizes a number of these chips using
3114 the chip identification register, and autoconfigures itself.
3115 @footnote{Currently there is a @command{stellaris mass_erase} command.
3116 That seems pointless since the same effect can be had using the
3117 standard @command{flash erase_address} command.}
3120 flash bank stellaris 0 0 0 0 $_TARGETNAME
3124 @deffn {Flash Driver} stm32x
3125 All members of the STM32 microcontroller family from ST Microelectronics
3126 include internal flash and use ARM Cortex M3 cores.
3127 The driver automatically recognizes a number of these chips using
3128 the chip identification register, and autoconfigures itself.
3131 flash bank stm32x 0 0 0 0 $_TARGETNAME
3134 Some stm32x-specific commands
3135 @footnote{Currently there is a @command{stm32x mass_erase} command.
3136 That seems pointless since the same effect can be had using the
3137 standard @command{flash erase_address} command.}
3140 @deffn Command {stm32x lock} num
3141 Locks the entire stm32 device.
3142 The @var{num} parameter is a value shown by @command{flash banks}.
3145 @deffn Command {stm32x unlock} num
3146 Unlocks the entire stm32 device.
3147 The @var{num} parameter is a value shown by @command{flash banks}.
3150 @deffn Command {stm32x options_read} num
3151 Read and display the stm32 option bytes written by
3152 the @command{stm32x options_write} command.
3153 The @var{num} parameter is a value shown by @command{flash banks}.
3156 @deffn Command {stm32x options_write} num (SWWDG|HWWDG) (RSTSTNDBY|NORSTSTNDBY) (RSTSTOP|NORSTSTOP)
3157 Writes the stm32 option byte with the specified values.
3158 The @var{num} parameter is a value shown by @command{flash banks}.
3162 @deffn {Flash Driver} str7x
3163 All members of the STR7 microcontroller family from ST Microelectronics
3164 include internal flash and use ARM7TDMI cores.
3165 The @var{str7x} driver defines one mandatory parameter, @var{variant},
3166 which is either @code{STR71x}, @code{STR73x} or @code{STR75x}.
3169 flash bank str7x 0x40000000 0x00040000 0 0 $_TARGETNAME STR71x
3173 @deffn {Flash Driver} str9x
3174 Most members of the STR9 microcontroller family from ST Microelectronics
3175 include internal flash and use ARM966E cores.
3176 The str9 needs the flash controller to be configured using
3177 the @command{str9x flash_config} command prior to Flash programming.
3180 flash bank str9x 0x40000000 0x00040000 0 0 $_TARGETNAME
3181 str9x flash_config 0 4 2 0 0x80000
3184 @deffn Command {str9x flash_config} num bbsr nbbsr bbadr nbbadr
3185 Configures the str9 flash controller.
3186 The @var{num} parameter is a value shown by @command{flash banks}.
3189 @item @var{bbsr} - Boot Bank Size register
3190 @item @var{nbbsr} - Non Boot Bank Size register
3191 @item @var{bbadr} - Boot Bank Start Address register
3192 @item @var{nbbadr} - Boot Bank Start Address register
3198 @deffn {Flash Driver} tms470
3199 Most members of the TMS470 microcontroller family from Texas Instruments
3200 include internal flash and use ARM7TDMI cores.
3201 This driver doesn't require the chip and bus width to be specified.
3203 Some tms470-specific commands are defined:
3205 @deffn Command {tms470 flash_keyset} key0 key1 key2 key3
3206 Saves programming keys in a register, to enable flash erase and write commands.
3209 @deffn Command {tms470 osc_mhz} clock_mhz
3210 Reports the clock speed, which is used to calculate timings.
3213 @deffn Command {tms470 plldis} (0|1)
3214 Disables (@var{1}) or enables (@var{0}) use of the PLL to speed up
3219 @subsection str9xpec driver
3222 Here is some background info to help
3223 you better understand how this driver works. OpenOCD has two flash drivers for
3227 Standard driver @option{str9x} programmed via the str9 core. Normally used for
3228 flash programming as it is faster than the @option{str9xpec} driver.
3230 Direct programming @option{str9xpec} using the flash controller. This is an
3231 ISC compilant (IEEE 1532) tap connected in series with the str9 core. The str9
3232 core does not need to be running to program using this flash driver. Typical use
3233 for this driver is locking/unlocking the target and programming the option bytes.
3236 Before we run any commands using the @option{str9xpec} driver we must first disable
3237 the str9 core. This example assumes the @option{str9xpec} driver has been
3238 configured for flash bank 0.
3240 # assert srst, we do not want core running
3241 # while accessing str9xpec flash driver
3243 # turn off target polling
3246 str9xpec enable_turbo 0
3248 str9xpec options_read 0
3249 # re-enable str9 core
3250 str9xpec disable_turbo 0
3254 The above example will read the str9 option bytes.
3255 When performing a unlock remember that you will not be able to halt the str9 - it
3256 has been locked. Halting the core is not required for the @option{str9xpec} driver
3257 as mentioned above, just issue the commands above manually or from a telnet prompt.
3259 @deffn {Flash Driver} str9xpec
3260 Only use this driver for locking/unlocking the device or configuring the option bytes.
3261 Use the standard str9 driver for programming.
3262 Before using the flash commands the turbo mode must be enabled using the
3263 @command{str9xpec enable_turbo} command.
3265 Several str9xpec-specific commands are defined:
3267 @deffn Command {str9xpec disable_turbo} num
3268 Restore the str9 into JTAG chain.
3271 @deffn Command {str9xpec enable_turbo} num
3272 Enable turbo mode, will simply remove the str9 from the chain and talk
3273 directly to the embedded flash controller.
3276 @deffn Command {str9xpec lock} num
3277 Lock str9 device. The str9 will only respond to an unlock command that will
3281 @deffn Command {str9xpec part_id} num
3282 Prints the part identifier for bank @var{num}.
3285 @deffn Command {str9xpec options_cmap} num (@option{bank0}|@option{bank1})
3286 Configure str9 boot bank.
3289 @deffn Command {str9xpec options_lvdsel} num (@option{vdd}|@option{vdd_vddq})
3290 Configure str9 lvd source.
3293 @deffn Command {str9xpec options_lvdthd} num (@option{2.4v}|@option{2.7v})
3294 Configure str9 lvd threshold.
3297 @deffn Command {str9xpec options_lvdwarn} bank (@option{vdd}|@option{vdd_vddq})
3298 Configure str9 lvd reset warning source.
3301 @deffn Command {str9xpec options_read} num
3302 Read str9 option bytes.
3305 @deffn Command {str9xpec options_write} num
3306 Write str9 option bytes.
3309 @deffn Command {str9xpec unlock} num
3318 @subsection mFlash Configuration
3319 @cindex mFlash Configuration
3321 @deffn {Config Command} {mflash bank} soc base RST_pin target
3322 Configures a mflash for @var{soc} host bank at
3324 The pin number format depends on the host GPIO naming convention.
3325 Currently, the mflash driver supports s3c2440 and pxa270.
3327 Example for s3c2440 mflash where @var{RST pin} is GPIO B1:
3330 mflash bank s3c2440 0x10000000 1b 0
3333 Example for pxa270 mflash where @var{RST pin} is GPIO 43:
3336 mflash bank pxa270 0x08000000 43 0
3340 @subsection mFlash commands
3341 @cindex mFlash commands
3343 @deffn Command {mflash config pll} frequency
3344 Configure mflash PLL.
3345 The @var{frequency} is the mflash input frequency, in Hz.
3346 Issuing this command will erase mflash's whole internal nand and write new pll.
3347 After this command, mflash needs power-on-reset for normal operation.
3348 If pll was newly configured, storage and boot(optional) info also need to be update.
3351 @deffn Command {mflash config boot}
3352 Configure bootable option.
3353 If bootable option is set, mflash offer the first 8 sectors
3357 @deffn Command {mflash config storage}
3358 Configure storage information.
3359 For the normal storage operation, this information must be
3363 @deffn Command {mflash dump} num filename offset size
3364 Dump @var{size} bytes, starting at @var{offset} bytes from the
3365 beginning of the bank @var{num}, to the file named @var{filename}.
3368 @deffn Command {mflash probe}
3372 @deffn Command {mflash write} num filename offset
3373 Write the binary file @var{filename} to mflash bank @var{num}, starting at
3374 @var{offset} bytes from the beginning of the bank.
3377 @node NAND Flash Commands
3378 @chapter NAND Flash Commands
3381 Compared to NOR or SPI flash, NAND devices are inexpensive
3382 and high density. Today's NAND chips, and multi-chip modules,
3383 commonly hold multiple GigaBytes of data.
3385 NAND chips consist of a number of ``erase blocks'' of a given
3386 size (such as 128 KBytes), each of which is divided into a
3387 number of pages (of perhaps 512 or 2048 bytes each). Each
3388 page of a NAND flash has an ``out of band'' (OOB) area to hold
3389 Error Correcting Code (ECC) and other metadata, usually 16 bytes
3390 of OOB for every 512 bytes of page data.
3392 One key characteristic of NAND flash is that its error rate
3393 is higher than that of NOR flash. In normal operation, that
3394 ECC is used to correct and detect errors. However, NAND
3395 blocks can also wear out and become unusable; those blocks
3396 are then marked "bad". NAND chips are even shipped from the
3397 manufacturer with a few bad blocks. The highest density chips
3398 use a technology (MLC) that wears out more quickly, so ECC
3399 support is increasingly important as a way to detect blocks
3400 that have begun to fail, and help to preserve data integrity
3401 with techniques such as wear leveling.
3403 Software is used to manage the ECC. Some controllers don't
3404 support ECC directly; in those cases, software ECC is used.
3405 Other controllers speed up the ECC calculations with hardware.
3406 Single-bit error correction hardware is routine. Controllers
3407 geared for newer MLC chips may correct 4 or more errors for
3408 every 512 bytes of data.
3410 You will need to make sure that any data you write using
3411 OpenOCD includes the apppropriate kind of ECC. For example,
3412 that may mean passing the @code{oob_softecc} flag when
3413 writing NAND data, or ensuring that the correct hardware
3416 The basic steps for using NAND devices include:
3418 @item Declare via the command @command{nand device}
3419 @* Do this in a board-specific configuration file,
3420 passing parameters as needed by the controller.
3421 @item Configure each device using @command{nand probe}.
3422 @* Do this only after the associated target is set up,
3423 such as in its reset-init script or in procures defined
3424 to access that device.
3425 @item Operate on the flash via @command{nand subcommand}
3426 @* Often commands to manipulate the flash are typed by a human, or run
3427 via a script in some automated way. Common task include writing a
3428 boot loader, operating system, or other data needed to initialize or
3432 @b{NOTE:} At the time this text was written, the largest NAND
3433 flash fully supported by OpenOCD is 2 GiBytes (16 GiBits).
3434 This is because the variables used to hold offsets and lengths
3435 are only 32 bits wide.
3436 (Larger chips may work in some cases, unless an offset or length
3437 is larger than 0xffffffff, the largest 32-bit unsigned integer.)
3438 Some larger devices will work, since they are actually multi-chip
3439 modules with two smaller chips and individual chipselect lines.
3441 @section NAND Configuration Commands
3442 @cindex NAND configuration
3444 NAND chips must be declared in configuration scripts,
3445 plus some additional configuration that's done after
3446 OpenOCD has initialized.
3448 @deffn {Config Command} {nand device} controller target [configparams...]
3449 Declares a NAND device, which can be read and written to
3450 after it has been configured through @command{nand probe}.
3451 In OpenOCD, devices are single chips; this is unlike some
3452 operating systems, which may manage multiple chips as if
3453 they were a single (larger) device.
3454 In some cases, configuring a device will activate extra
3455 commands; see the controller-specific documentation.
3457 @b{NOTE:} This command is not available after OpenOCD
3458 initialization has completed. Use it in board specific
3459 configuration files, not interactively.
3462 @item @var{controller} ... identifies the controller driver
3463 associated with the NAND device being declared.
3464 @xref{NAND Driver List}.
3465 @item @var{target} ... names the target used when issuing
3466 commands to the NAND controller.
3467 @comment Actually, it's currently a controller-specific parameter...
3468 @item @var{configparams} ... controllers may support, or require,
3469 additional parameters. See the controller-specific documentation
3470 for more information.
3474 @deffn Command {nand list}
3475 Prints a one-line summary of each device declared
3476 using @command{nand device}, numbered from zero.
3477 Note that un-probed devices show no details.
3480 @deffn Command {nand probe} num
3481 Probes the specified device to determine key characteristics
3482 like its page and block sizes, and how many blocks it has.
3483 The @var{num} parameter is the value shown by @command{nand list}.
3484 You must (successfully) probe a device before you can use
3485 it with most other NAND commands.
3488 @section Erasing, Reading, Writing to NAND Flash
3490 @deffn Command {nand dump} num filename offset length [oob_option]
3491 @cindex NAND reading
3492 Reads binary data from the NAND device and writes it to the file,
3493 starting at the specified offset.
3494 The @var{num} parameter is the value shown by @command{nand list}.
3496 Use a complete path name for @var{filename}, so you don't depend
3497 on the directory used to start the OpenOCD server.
3499 The @var{offset} and @var{length} must be exact multiples of the
3500 device's page size. They describe a data region; the OOB data
3501 associated with each such page may also be accessed.
3503 @b{NOTE:} At the time this text was written, no error correction
3504 was done on the data that's read, unless raw access was disabled
3505 and the underlying NAND controller driver had a @code{read_page}
3506 method which handled that error correction.
3508 By default, only page data is saved to the specified file.
3509 Use an @var{oob_option} parameter to save OOB data:
3511 @item no oob_* parameter
3512 @*Output file holds only page data; OOB is discarded.
3513 @item @code{oob_raw}
3514 @*Output file interleaves page data and OOB data;
3515 the file will be longer than "length" by the size of the
3516 spare areas associated with each data page.
3517 Note that this kind of "raw" access is different from
3518 what's implied by @command{nand raw_access}, which just
3519 controls whether a hardware-aware access method is used.
3520 @item @code{oob_only}
3521 @*Output file has only raw OOB data, and will
3522 be smaller than "length" since it will contain only the
3523 spare areas associated with each data page.
3527 @deffn Command {nand erase} num offset length
3528 @cindex NAND erasing
3529 @cindex NAND programming
3530 Erases blocks on the specified NAND device, starting at the
3531 specified @var{offset} and continuing for @var{length} bytes.
3532 Both of those values must be exact multiples of the device's
3533 block size, and the region they specify must fit entirely in the chip.
3534 The @var{num} parameter is the value shown by @command{nand list}.
3536 @b{NOTE:} This command will try to erase bad blocks, when told
3537 to do so, which will probably invalidate the manufacturer's bad
3539 For the remainder of the current server session, @command{nand info}
3540 will still report that the block ``is'' bad.
3543 @deffn Command {nand write} num filename offset [option...]
3544 @cindex NAND writing
3545 @cindex NAND programming
3546 Writes binary data from the file into the specified NAND device,
3547 starting at the specified offset. Those pages should already
3548 have been erased; you can't change zero bits to one bits.
3549 The @var{num} parameter is the value shown by @command{nand list}.
3551 Use a complete path name for @var{filename}, so you don't depend
3552 on the directory used to start the OpenOCD server.
3554 The @var{offset} must be an exact multiple of the device's page size.
3555 All data in the file will be written, assuming it doesn't run
3556 past the end of the device.
3557 Only full pages are written, and any extra space in the last
3558 page will be filled with 0xff bytes. (That includes OOB data,
3559 if that's being written.)
3561 @b{NOTE:} At the time this text was written, bad blocks are
3562 ignored. That is, this routine will not skip bad blocks,
3563 but will instead try to write them. This can cause problems.
3565 Provide at most one @var{option} parameter. With some
3566 NAND drivers, the meanings of these parameters may change
3567 if @command{nand raw_access} was used to disable hardware ECC.
3569 @item no oob_* parameter
3570 @*File has only page data, which is written.
3571 If raw acccess is in use, the OOB area will not be written.
3572 Otherwise, if the underlying NAND controller driver has
3573 a @code{write_page} routine, that routine may write the OOB
3574 with hardware-computed ECC data.
3575 @item @code{oob_only}
3576 @*File has only raw OOB data, which is written to the OOB area.
3577 Each page's data area stays untouched. @i{This can be a dangerous
3578 option}, since it can invalidate the ECC data.
3579 You may need to force raw access to use this mode.
3580 @item @code{oob_raw}
3581 @*File interleaves data and OOB data, both of which are written
3582 If raw access is enabled, the data is written first, then the
3584 Otherwise, if the underlying NAND controller driver has
3585 a @code{write_page} routine, that routine may modify the OOB
3586 before it's written, to include hardware-computed ECC data.
3587 @item @code{oob_softecc}
3588 @*File has only page data, which is written.
3589 The OOB area is filled with 0xff, except for a standard 1-bit
3590 software ECC code stored in conventional locations.
3591 You might need to force raw access to use this mode, to prevent
3592 the underlying driver from applying hardware ECC.
3593 @item @code{oob_softecc_kw}
3594 @*File has only page data, which is written.
3595 The OOB area is filled with 0xff, except for a 4-bit software ECC
3596 specific to the boot ROM in Marvell Kirkwood SoCs.
3597 You might need to force raw access to use this mode, to prevent
3598 the underlying driver from applying hardware ECC.
3602 @section Other NAND commands
3603 @cindex NAND other commands
3605 @deffn Command {nand check_bad_blocks} [offset length]
3606 Checks for manufacturer bad block markers on the specified NAND
3607 device. If no parameters are provided, checks the whole
3608 device; otherwise, starts at the specified @var{offset} and
3609 continues for @var{length} bytes.
3610 Both of those values must be exact multiples of the device's
3611 block size, and the region they specify must fit entirely in the chip.
3612 The @var{num} parameter is the value shown by @command{nand list}.
3614 @b{NOTE:} Before using this command you should force raw access
3615 with @command{nand raw_access enable} to ensure that the underlying
3616 driver will not try to apply hardware ECC.
3619 @deffn Command {nand info} num
3620 The @var{num} parameter is the value shown by @command{nand list}.
3621 This prints the one-line summary from "nand list", plus for
3622 devices which have been probed this also prints any known
3623 status for each block.
3626 @deffn Command {nand raw_access} num (@option{enable}|@option{disable})
3627 Sets or clears an flag affecting how page I/O is done.
3628 The @var{num} parameter is the value shown by @command{nand list}.
3630 This flag is cleared (disabled) by default, but changing that
3631 value won't affect all NAND devices. The key factor is whether
3632 the underlying driver provides @code{read_page} or @code{write_page}
3633 methods. If it doesn't provide those methods, the setting of
3634 this flag is irrelevant; all access is effectively ``raw''.
3636 When those methods exist, they are normally used when reading
3637 data (@command{nand dump} or reading bad block markers) or
3638 writing it (@command{nand write}). However, enabling
3639 raw access (setting the flag) prevents use of those methods,
3640 bypassing hardware ECC logic.
3641 @i{This can be a dangerous option}, since writing blocks
3642 with the wrong ECC data can cause them to be marked as bad.
3645 @anchor{NAND Driver List}
3646 @section NAND Drivers, Options, and Commands
3647 As noted above, the @command{nand device} command allows
3648 driver-specific options and behaviors.
3649 Some controllers also activate controller-specific commands.
3651 @deffn {NAND Driver} davinci
3652 This driver handles the NAND controllers found on DaVinci family
3653 chips from Texas Instruments.
3654 It takes three extra parameters:
3655 address of the NAND chip;
3656 hardware ECC mode to use (hwecc1, hwecc4, hwecc4_infix);
3657 address of the AEMIF controller on this processor.
3659 nand device davinci dm355.arm 0x02000000 hwecc4 0x01e10000
3661 All DaVinci processors support the single-bit ECC hardware,
3662 and newer ones also support the four-bit ECC hardware.
3663 The @code{write_page} and @code{read_page} methods are used
3664 to implement those ECC modes, unless they are disabled using
3665 the @command{nand raw_access} command.
3668 @deffn {NAND Driver} lpc3180
3669 These controllers require an extra @command{nand device}
3670 parameter: the clock rate used by the controller.
3671 @deffn Command {lpc3180 select} num [mlc|slc]
3672 Configures use of the MLC or SLC controller mode.
3673 MLC implies use of hardware ECC.
3674 The @var{num} parameter is the value shown by @command{nand list}.
3677 At this writing, this driver includes @code{write_page}
3678 and @code{read_page} methods. Using @command{nand raw_access}
3679 to disable those methods will prevent use of hardware ECC
3680 in the MLC controller mode, but won't change SLC behavior.
3682 @comment current lpc3180 code won't issue 5-byte address cycles
3684 @deffn {NAND Driver} orion
3685 These controllers require an extra @command{nand device}
3686 parameter: the address of the controller.
3688 nand device orion 0xd8000000
3690 These controllers don't define any specialized commands.
3691 At this writing, their drivers don't include @code{write_page}
3692 or @code{read_page} methods, so @command{nand raw_access} won't
3693 change any behavior.
3696 @deffn {NAND Driver} s3c2410
3697 @deffnx {NAND Driver} s3c2412
3698 @deffnx {NAND Driver} s3c2440
3699 @deffnx {NAND Driver} s3c2443
3700 These S3C24xx family controllers don't have any special
3701 @command{nand device} options, and don't define any
3702 specialized commands.
3703 At this writing, their drivers don't include @code{write_page}
3704 or @code{read_page} methods, so @command{nand raw_access} won't
3705 change any behavior.
3708 @node General Commands
3709 @chapter General Commands
3712 The commands documented in this chapter here are common commands that
3713 you, as a human, may want to type and see the output of. Configuration type
3714 commands are documented elsewhere.
3718 @item @b{Source Of Commands}
3719 @* OpenOCD commands can occur in a configuration script (discussed
3720 elsewhere) or typed manually by a human or supplied programatically,
3721 or via one of several TCP/IP Ports.
3723 @item @b{From the human}
3724 @* A human should interact with the telnet interface (default port: 4444)
3725 or via GDB (default port 3333).
3727 To issue commands from within a GDB session, use the @option{monitor}
3728 command, e.g. use @option{monitor poll} to issue the @option{poll}
3729 command. All output is relayed through the GDB session.
3731 @item @b{Machine Interface}
3732 The Tcl interface's intent is to be a machine interface. The default Tcl
3737 @section Daemon Commands
3739 @deffn Command sleep msec [@option{busy}]
3740 Wait for at least @var{msec} milliseconds before resuming.
3741 If @option{busy} is passed, busy-wait instead of sleeping.
3742 (This option is strongly discouraged.)
3743 Useful in connection with script files
3744 (@command{script} command and @command{target_name} configuration).
3747 @deffn Command shutdown
3748 Close the OpenOCD daemon, disconnecting all clients (GDB, telnet, other).
3751 @anchor{debug_level}
3752 @deffn Command debug_level [n]
3753 @cindex message level
3754 Display debug level.
3755 If @var{n} (from 0..3) is provided, then set it to that level.
3756 This affects the kind of messages sent to the server log.
3757 Level 0 is error messages only;
3758 level 1 adds warnings;
3759 level 2 (the default) adds informational messages;
3760 and level 3 adds debugging messages.
3763 @deffn Command fast (@option{enable}|@option{disable})
3765 Set default behaviour of OpenOCD to be "fast and dangerous".
3767 At this writing, this only affects the defaults for two ARM7/ARM9 parameters:
3768 fast memory access, and DCC downloads. Those parameters may still be
3769 individually overridden.
3771 The target specific "dangerous" optimisation tweaking options may come and go
3772 as more robust and user friendly ways are found to ensure maximum throughput
3773 and robustness with a minimum of configuration.
3775 Typically the "fast enable" is specified first on the command line:
3778 openocd -c "fast enable" -c "interface dummy" -f target/str710.cfg
3782 @deffn Command echo message
3783 Logs a message at "user" priority.
3784 Output @var{message} to stdout.
3786 echo "Downloading kernel -- please wait"
3790 @deffn Command log_output [filename]
3791 Redirect logging to @var{filename};
3792 the initial log output channel is stderr.
3795 @anchor{Target State handling}
3796 @section Target State handling
3799 @cindex target initialization
3801 In this section ``target'' refers to a CPU configured as
3802 shown earlier (@pxref{CPU Configuration}).
3803 These commands, like many, implicitly refer to
3804 a @dfn{current target} which is used to perform the
3805 various operations. The current target may be changed
3806 by using @command{targets} command with the name of the
3807 target which should become current.
3809 @deffn Command reg [(number|name) [value]]
3810 Access a single register by @var{number} or by its @var{name}.
3812 @emph{With no arguments}:
3813 list all available registers for the current target,
3814 showing number, name, size, value, and cache status.
3816 @emph{With number/name}: display that register's value.
3818 @emph{With both number/name and value}: set register's value.
3820 Cores may have surprisingly many registers in their
3821 Debug and trace infrastructure:
3825 (0) r0 (/32): 0x0000D3C2 (dirty: 1, valid: 1)
3826 (1) r1 (/32): 0xFD61F31C (dirty: 0, valid: 1)
3827 (2) r2 (/32): 0x00022551 (dirty: 0, valid: 1)
3829 (164) ETM_CONTEXTID_COMPARATOR_MASK (/32): \
3830 0x00000000 (dirty: 0, valid: 0)
3835 @deffn Command halt [ms]
3836 @deffnx Command wait_halt [ms]
3837 The @command{halt} command first sends a halt request to the target,
3838 which @command{wait_halt} doesn't.
3839 Otherwise these behave the same: wait up to @var{ms} milliseconds,
3840 or 5 seconds if there is no parameter, for the target to halt
3841 (and enter debug mode).
3842 Using 0 as the @var{ms} parameter prevents OpenOCD from waiting.
3845 @deffn Command resume [address]
3846 Resume the target at its current code position,
3847 or the optional @var{address} if it is provided.
3848 OpenOCD will wait 5 seconds for the target to resume.
3851 @deffn Command step [address]
3852 Single-step the target at its current code position,
3853 or the optional @var{address} if it is provided.
3856 @anchor{Reset Command}
3857 @deffn Command reset
3858 @deffnx Command {reset run}
3859 @deffnx Command {reset halt}
3860 @deffnx Command {reset init}
3861 Perform as hard a reset as possible, using SRST if possible.
3862 @emph{All defined targets will be reset, and target
3863 events will fire during the reset sequence.}
3865 The optional parameter specifies what should
3866 happen after the reset.
3867 If there is no parameter, a @command{reset run} is executed.
3868 The other options will not work on all systems.
3869 @xref{Reset Configuration}.
3872 @item @b{run} Let the target run
3873 @item @b{halt} Immediately halt the target
3874 @item @b{init} Immediately halt the target, and execute the reset-init script
3878 @deffn Command soft_reset_halt
3879 Requesting target halt and executing a soft reset. This is often used
3880 when a target cannot be reset and halted. The target, after reset is
3881 released begins to execute code. OpenOCD attempts to stop the CPU and
3882 then sets the program counter back to the reset vector. Unfortunately
3883 the code that was executed may have left the hardware in an unknown
3887 @section I/O Utilities
3889 These commands are available when
3890 OpenOCD is built with @option{--enable-ioutil}.
3891 They are mainly useful on embedded targets;
3892 PC type hosts have complementary tools.
3894 @emph{Note:} there are several more such commands.
3896 @deffn Command meminfo
3897 Display available RAM memory on OpenOCD host.
3898 Used in OpenOCD regression testing scripts.
3901 @anchor{Memory access}
3902 @section Memory access commands
3903 @cindex memory access
3905 These commands allow accesses of a specific size to the memory
3906 system. Often these are used to configure the current target in some
3907 special way. For example - one may need to write certain values to the
3908 SDRAM controller to enable SDRAM.
3911 @item Use the @command{targets} (plural) command
3912 to change the current target.
3913 @item In system level scripts these commands are deprecated.
3914 Please use their TARGET object siblings to avoid making assumptions
3915 about what TAP is the current target, or about MMU configuration.
3918 @deffn Command mdw addr [count]
3919 @deffnx Command mdh addr [count]
3920 @deffnx Command mdb addr [count]
3921 Display contents of address @var{addr}, as
3922 32-bit words (@command{mdw}), 16-bit halfwords (@command{mdh}),
3923 or 8-bit bytes (@command{mdb}).
3924 If @var{count} is specified, displays that many units.
3925 (If you want to manipulate the data instead of displaying it,
3926 see the @code{mem2array} primitives.)
3929 @deffn Command mww addr word
3930 @deffnx Command mwh addr halfword
3931 @deffnx Command mwb addr byte
3932 Writes the specified @var{word} (32 bits),
3933 @var{halfword} (16 bits), or @var{byte} (8-bit) pattern,
3934 at the specified address @var{addr}.
3938 @anchor{Image access}
3939 @section Image loading commands
3940 @cindex image loading
3941 @cindex image dumping
3944 @deffn Command {dump_image} filename address size
3945 Dump @var{size} bytes of target memory starting at @var{address} to the
3946 binary file named @var{filename}.
3949 @deffn Command {fast_load}
3950 Loads an image stored in memory by @command{fast_load_image} to the
3951 current target. Must be preceeded by fast_load_image.
3954 @deffn Command {fast_load_image} filename address [@option{bin}|@option{ihex}|@option{elf}]
3955 Normally you should be using @command{load_image} or GDB load. However, for
3956 testing purposes or when I/O overhead is significant(OpenOCD running on an embedded
3957 host), storing the image in memory and uploading the image to the target
3958 can be a way to upload e.g. multiple debug sessions when the binary does not change.
3959 Arguments are the same as @command{load_image}, but the image is stored in OpenOCD host
3960 memory, i.e. does not affect target. This approach is also useful when profiling
3961 target programming performance as I/O and target programming can easily be profiled
3966 @deffn Command {load_image} filename address [@option{bin}|@option{ihex}|@option{elf}]
3967 Load image from file @var{filename} to target memory at @var{address}.
3968 The file format may optionally be specified
3969 (@option{bin}, @option{ihex}, or @option{elf})
3972 @deffn Command {verify_image} filename address [@option{bin}|@option{ihex}|@option{elf}]
3973 Verify @var{filename} against target memory starting at @var{address}.
3974 The file format may optionally be specified
3975 (@option{bin}, @option{ihex}, or @option{elf})
3976 This will first attempt a comparison using a CRC checksum, if this fails it will try a binary compare.
3980 @section Breakpoint and Watchpoint commands
3984 CPUs often make debug modules accessible through JTAG, with
3985 hardware support for a handful of code breakpoints and data
3987 In addition, CPUs almost always support software breakpoints.
3989 @deffn Command {bp} [address len [@option{hw}]]
3990 With no parameters, lists all active breakpoints.
3991 Else sets a breakpoint on code execution starting
3992 at @var{address} for @var{length} bytes.
3993 This is a software breakpoint, unless @option{hw} is specified
3994 in which case it will be a hardware breakpoint.
3997 @deffn Command {rbp} address
3998 Remove the breakpoint at @var{address}.
4001 @deffn Command {rwp} address
4002 Remove data watchpoint on @var{address}
4005 @deffn Command {wp} [address len [(@option{r}|@option{w}|@option{a}) [value [mask]]]]
4006 With no parameters, lists all active watchpoints.
4007 Else sets a data watchpoint on data from @var{address} for @var{length} bytes.
4008 The watch point is an "access" watchpoint unless
4009 the @option{r} or @option{w} parameter is provided,
4010 defining it as respectively a read or write watchpoint.
4011 If a @var{value} is provided, that value is used when determining if
4012 the watchpoint should trigger. The value may be first be masked
4013 using @var{mask} to mark ``don't care'' fields.
4016 @section Misc Commands
4019 @deffn Command {profile} seconds filename
4020 Profiling samples the CPU's program counter as quickly as possible,
4021 which is useful for non-intrusive stochastic profiling.
4022 Saves up to 10000 sampines in @file{filename} using ``gmon.out'' format.
4025 @node Architecture and Core Commands
4026 @chapter Architecture and Core Commands
4027 @cindex Architecture Specific Commands
4028 @cindex Core Specific Commands
4030 Most CPUs have specialized JTAG operations to support debugging.
4031 OpenOCD packages most such operations in its standard command framework.
4032 Some of those operations don't fit well in that framework, so they are
4033 exposed here as architecture or implementation (core) specific commands.
4035 @anchor{ARM Tracing}
4036 @section ARM Tracing
4040 CPUs based on ARM cores may include standard tracing interfaces,
4041 based on an ``Embedded Trace Module'' (ETM) which sends voluminous
4042 address and data bus trace records to a ``Trace Port''.
4046 Development-oriented boards will sometimes provide a high speed
4047 trace connector for collecting that data, when the particular CPU
4048 supports such an interface.
4049 (The standard connector is a 38-pin Mictor, with both JTAG
4050 and trace port support.)
4051 Those trace connectors are supported by higher end JTAG adapters
4052 and some logic analyzer modules; frequently those modules can
4053 buffer several megabytes of trace data.
4054 Configuring an ETM coupled to such an external trace port belongs
4055 in the board-specific configuration file.
4057 If the CPU doesn't provide an external interface, it probably
4058 has an ``Embedded Trace Buffer'' (ETB) on the chip, which is a
4059 dedicated SRAM. 4KBytes is one common ETB size.
4060 Configuring an ETM coupled only to an ETB belongs in the CPU-specific
4061 (target) configuration file, since it works the same on all boards.
4064 ETM support in OpenOCD doesn't seem to be widely used yet.
4067 ETM support may be buggy, and at least some @command{etm config}
4068 parameters should be detected by asking the ETM for them.
4069 It seems like a GDB hookup should be possible,
4070 as well as triggering trace on specific events
4071 (perhaps @emph{handling IRQ 23} or @emph{calls foo()}).
4072 There should be GUI tools to manipulate saved trace data and help
4073 analyse it in conjunction with the source code.
4074 It's unclear how much of a common interface is shared
4075 with the current XScale trace support, or should be
4076 shared with eventual Nexus-style trace module support.
4079 @subsection ETM Configuration
4080 ETM setup is coupled with the trace port driver configuration.
4082 @deffn {Config Command} {etm config} target width mode clocking driver
4083 Declares the ETM associated with @var{target}, and associates it
4084 with a given trace port @var{driver}. @xref{Trace Port Drivers}.
4086 Several of the parameters must reflect the trace port configuration.
4087 The @var{width} must be either 4, 8, or 16.
4088 The @var{mode} must be @option{normal}, @option{multiplexted},
4089 or @option{demultiplexted}.
4090 The @var{clocking} must be @option{half} or @option{full}.
4093 You can see the ETM registers using the @command{reg} command, although
4094 not all of those possible registers are present in every ETM.
4098 @deffn Command {etm info}
4099 Displays information about the current target's ETM.
4102 @deffn Command {etm status}
4103 Displays status of the current target's ETM:
4104 is the ETM idle, or is it collecting data?
4105 Did trace data overflow?
4109 @deffn Command {etm tracemode} [type context_id_bits cycle_accurate branch_output]
4110 Displays what data that ETM will collect.
4111 If arguments are provided, first configures that data.
4112 When the configuration changes, tracing is stopped
4113 and any buffered trace data is invalidated.
4116 @item @var{type} ... one of
4117 @option{none} (save nothing),
4118 @option{data} (save data),
4119 @option{address} (save addresses),
4120 @option{all} (save data and addresses)
4121 @item @var{context_id_bits} ... 0, 8, 16, or 32
4122 @item @var{cycle_accurate} ... @option{enable} or @option{disable}
4123 @item @var{branch_output} ... @option{enable} or @option{disable}
4127 @deffn Command {etm trigger_percent} percent
4128 @emph{Buggy and effectively a NOP ... @var{percent} from 2..100}
4131 @subsection ETM Trace Operation
4133 After setting up the ETM, you can use it to collect data.
4134 That data can be exported to files for later analysis.
4135 It can also be parsed with OpenOCD, for basic sanity checking.
4137 @deffn Command {etm analyze}
4138 Reads trace data into memory, if it wasn't already present.
4139 Decodes and prints the data that was collected.
4142 @deffn Command {etm dump} filename
4143 Stores the captured trace data in @file{filename}.
4146 @deffn Command {etm image} filename [base_address] [type]
4147 Opens an image file.
4150 @deffn Command {etm load} filename
4151 Loads captured trace data from @file{filename}.
4154 @deffn Command {etm start}
4155 Starts trace data collection.
4158 @deffn Command {etm stop}
4159 Stops trace data collection.
4162 @anchor{Trace Port Drivers}
4163 @subsection Trace Port Drivers
4165 To use an ETM trace port it must be associated with a driver.
4167 @deffn {Trace Port Driver} dummy
4168 Use the @option{dummy} driver if you are configuring an ETM that's
4169 not connected to anything (on-chip ETB or off-chip trace connector).
4170 @emph{This driver lets OpenOCD talk to the ETM, but it does not expose
4171 any trace data collection.}
4172 @deffn {Config Command} {etm_dummy config} target
4173 Associates the ETM for @var{target} with a dummy driver.
4177 @deffn {Trace Port Driver} etb
4178 Use the @option{etb} driver if you are configuring an ETM
4179 to use on-chip ETB memory.
4180 @deffn {Config Command} {etb config} target etb_tap
4181 Associates the ETM for @var{target} with the ETB at @var{etb_tap}.
4182 You can see the ETB registers using the @command{reg} command.
4186 @deffn {Trace Port Driver} oocd_trace
4187 This driver isn't available unless OpenOCD was explicitly configured
4188 with the @option{--enable-oocd_trace} option. You probably don't want
4189 to configure it unless you've built the appropriate prototype hardware;
4190 it's @emph{proof-of-concept} software.
4192 Use the @option{oocd_trace} driver if you are configuring an ETM that's
4193 connected to an off-chip trace connector.
4195 @deffn {Config Command} {oocd_trace config} target tty
4196 Associates the ETM for @var{target} with a trace driver which
4197 collects data through the serial port @var{tty}.
4200 @deffn Command {oocd_trace resync}
4201 Re-synchronizes with the capture clock.
4204 @deffn Command {oocd_trace status}
4205 Reports whether the capture clock is locked or not.
4210 @section ARMv4 and ARMv5 Architecture
4214 These commands are specific to ARM architecture v4 and v5,
4215 including all ARM7 or ARM9 systems and Intel XScale.
4216 They are available in addition to other core-specific
4217 commands that may be available.
4219 @deffn Command {armv4_5 core_state} [@option{arm}|@option{thumb}]
4220 Displays the core_state, optionally changing it to process
4221 either @option{arm} or @option{thumb} instructions.
4222 The target may later be resumed in the currently set core_state.
4223 (Processors may also support the Jazelle state, but
4224 that is not currently supported in OpenOCD.)
4227 @deffn Command {armv4_5 disassemble} address count [thumb]
4229 Disassembles @var{count} instructions starting at @var{address}.
4230 If @option{thumb} is specified, Thumb (16-bit) instructions are used;
4231 else ARM (32-bit) instructions are used.
4232 (Processors may also support the Jazelle state, but
4233 those instructions are not currently understood by OpenOCD.)
4236 @deffn Command {armv4_5 reg}
4237 Display a table of all banked core registers, fetching the current value from every
4238 core mode if necessary. OpenOCD versions before rev. 60 didn't fetch the current
4242 @subsection ARM7 and ARM9 specific commands
4246 These commands are specific to ARM7 and ARM9 cores, like ARM7TDMI, ARM720T,
4247 ARM9TDMI, ARM920T or ARM926EJ-S.
4248 They are available in addition to the ARMv4/5 commands,
4249 and any other core-specific commands that may be available.
4251 @deffn Command {arm7_9 dbgrq} (@option{enable}|@option{disable})
4252 Control use of the EmbeddedIce DBGRQ signal to force entry into debug mode,
4253 instead of breakpoints. This should be
4254 safe for all but ARM7TDMI--S cores (like Philips LPC).
4257 @deffn Command {arm7_9 dcc_downloads} (@option{enable}|@option{disable})
4259 Control the use of the debug communications channel (DCC) to write larger (>128 byte)
4260 amounts of memory. DCC downloads offer a huge speed increase, but might be
4261 unsafe, especially with targets running at very low speeds. This command was introduced
4262 with OpenOCD rev. 60, and requires a few bytes of working area.
4265 @anchor{arm7_9 fast_memory_access}
4266 @deffn Command {arm7_9 fast_memory_access} (@option{enable}|@option{disable})
4267 Enable or disable memory writes and reads that don't check completion of
4268 the operation. This provides a huge speed increase, especially with USB JTAG
4269 cables (FT2232), but might be unsafe if used with targets running at very low
4270 speeds, like the 32kHz startup clock of an AT91RM9200.
4273 @deffn {Debug Command} {arm7_9 write_core_reg} num mode word
4274 @emph{This is intended for use while debugging OpenOCD; you probably
4277 Writes a 32-bit @var{word} to register @var{num} (from 0 to 16)
4278 as used in the specified @var{mode}
4279 (where e.g. mode 16 is "user" and mode 19 is "supervisor";
4280 the M4..M0 bits of the PSR).
4281 Registers 0..15 are the normal CPU registers such as r0(0), r1(1) ... pc(15).
4282 Register 16 is the mode-specific SPSR,
4283 unless the specified mode is 0xffffffff (32-bit all-ones)
4284 in which case register 16 is the CPSR.
4285 The write goes directly to the CPU, bypassing the register cache.
4288 @deffn {Debug Command} {arm7_9 write_xpsr} word (@option{0}|@option{1})
4289 @emph{This is intended for use while debugging OpenOCD; you probably
4292 If the second parameter is zero, writes @var{word} to the
4293 Current Program Status register (CPSR).
4294 Else writes @var{word} to the current mode's Saved PSR (SPSR).
4295 In both cases, this bypasses the register cache.
4298 @deffn {Debug Command} {arm7_9 write_xpsr_im8} byte rotate (@option{0}|@option{1})
4299 @emph{This is intended for use while debugging OpenOCD; you probably
4302 Writes eight bits to the CPSR or SPSR,
4303 first rotating them by @math{2*rotate} bits,
4304 and bypassing the register cache.
4305 This has lower JTAG overhead than writing the entire CPSR or SPSR
4306 with @command{arm7_9 write_xpsr}.
4309 @subsection ARM720T specific commands
4312 These commands are available to ARM720T based CPUs,
4313 which are implementations of the ARMv4T architecture
4314 based on the ARM7TDMI-S integer core.
4315 They are available in addition to the ARMv4/5 and ARM7/ARM9 commands.
4317 @deffn Command {arm720t cp15} regnum [value]
4318 Display cp15 register @var{regnum};
4319 else if a @var{value} is provided, that value is written to that register.
4322 @deffn Command {arm720t mdw_phys} addr [count]
4323 @deffnx Command {arm720t mdh_phys} addr [count]
4324 @deffnx Command {arm720t mdb_phys} addr [count]
4325 Display contents of physical address @var{addr}, as
4326 32-bit words (@command{mdw_phys}), 16-bit halfwords (@command{mdh_phys}),
4327 or 8-bit bytes (@command{mdb_phys}).
4328 If @var{count} is specified, displays that many units.
4331 @deffn Command {arm720t mww_phys} addr word
4332 @deffnx Command {arm720t mwh_phys} addr halfword
4333 @deffnx Command {arm720t mwb_phys} addr byte
4334 Writes the specified @var{word} (32 bits),
4335 @var{halfword} (16 bits), or @var{byte} (8-bit) pattern,
4336 at the specified physical address @var{addr}.
4339 @deffn Command {arm720t virt2phys} va
4340 Translate a virtual address @var{va} to a physical address
4341 and display the result.
4344 @subsection ARM9TDMI specific commands
4347 Many ARM9-family CPUs are built around ARM9TDMI integer cores,
4348 or processors resembling ARM9TDMI, and can use these commands.
4349 Such cores include the ARM920T, ARM926EJ-S, and ARM966.
4351 @deffn Command {arm9tdmi vector_catch} (@option{all}|@option{none}|list)
4352 Catch arm9 interrupt vectors, can be @option{all}, @option{none},
4353 or a list with one or more of the following:
4354 @option{reset} @option{undef} @option{swi} @option{pabt} @option{dabt} @option{reserved}
4355 @option{irq} @option{fiq}.
4358 @subsection ARM920T specific commands
4361 These commands are available to ARM920T based CPUs,
4362 which are implementations of the ARMv4T architecture
4363 built using the ARM9TDMI integer core.
4364 They are available in addition to the ARMv4/5, ARM7/ARM9,
4365 and ARM9TDMI commands.
4367 @deffn Command {arm920t cache_info}
4368 Print information about the caches found. This allows to see whether your target
4369 is an ARM920T (2x16kByte cache) or ARM922T (2x8kByte cache).
4372 @deffn Command {arm920t cp15} regnum [value]
4373 Display cp15 register @var{regnum};
4374 else if a @var{value} is provided, that value is written to that register.
4377 @deffn Command {arm920t cp15i} opcode [value [address]]
4378 Interpreted access using cp15 @var{opcode}.
4379 If no @var{value} is provided, the result is displayed.
4380 Else if that value is written using the specified @var{address},
4381 or using zero if no other address is not provided.
4384 @deffn Command {arm920t mdw_phys} addr [count]
4385 @deffnx Command {arm920t mdh_phys} addr [count]
4386 @deffnx Command {arm920t mdb_phys} addr [count]
4387 Display contents of physical address @var{addr}, as
4388 32-bit words (@command{mdw_phys}), 16-bit halfwords (@command{mdh_phys}),
4389 or 8-bit bytes (@command{mdb_phys}).
4390 If @var{count} is specified, displays that many units.
4393 @deffn Command {arm920t mww_phys} addr word
4394 @deffnx Command {arm920t mwh_phys} addr halfword
4395 @deffnx Command {arm920t mwb_phys} addr byte
4396 Writes the specified @var{word} (32 bits),
4397 @var{halfword} (16 bits), or @var{byte} (8-bit) pattern,
4398 at the specified physical address @var{addr}.
4401 @deffn Command {arm920t read_cache} filename
4402 Dump the content of ICache and DCache to a file named @file{filename}.
4405 @deffn Command {arm920t read_mmu} filename
4406 Dump the content of the ITLB and DTLB to a file named @file{filename}.
4409 @deffn Command {arm920t virt2phys} va
4410 Translate a virtual address @var{va} to a physical address
4411 and display the result.
4414 @subsection ARM926ej-s specific commands
4417 These commands are available to ARM926ej-s based CPUs,
4418 which are implementations of the ARMv5TEJ architecture
4419 based on the ARM9EJ-S integer core.
4420 They are available in addition to the ARMv4/5, ARM7/ARM9,
4421 and ARM9TDMI commands.
4423 The Feroceon cores also support these commands, although
4424 they are not built from ARM926ej-s designs.
4426 @deffn Command {arm926ejs cache_info}
4427 Print information about the caches found.
4430 @deffn Command {arm926ejs cp15} opcode1 opcode2 CRn CRm regnum [value]
4431 Accesses cp15 register @var{regnum} using
4432 @var{opcode1}, @var{opcode2}, @var{CRn}, and @var{CRm}.
4433 If a @var{value} is provided, that value is written to that register.
4434 Else that register is read and displayed.
4437 @deffn Command {arm926ejs mdw_phys} addr [count]
4438 @deffnx Command {arm926ejs mdh_phys} addr [count]
4439 @deffnx Command {arm926ejs mdb_phys} addr [count]
4440 Display contents of physical address @var{addr}, as
4441 32-bit words (@command{mdw_phys}), 16-bit halfwords (@command{mdh_phys}),
4442 or 8-bit bytes (@command{mdb_phys}).
4443 If @var{count} is specified, displays that many units.
4446 @deffn Command {arm926ejs mww_phys} addr word
4447 @deffnx Command {arm926ejs mwh_phys} addr halfword
4448 @deffnx Command {arm926ejs mwb_phys} addr byte
4449 Writes the specified @var{word} (32 bits),
4450 @var{halfword} (16 bits), or @var{byte} (8-bit) pattern,
4451 at the specified physical address @var{addr}.
4454 @deffn Command {arm926ejs virt2phys} va
4455 Translate a virtual address @var{va} to a physical address
4456 and display the result.
4459 @subsection ARM966E specific commands
4462 These commands are available to ARM966 based CPUs,
4463 which are implementations of the ARMv5TE architecture.
4464 They are available in addition to the ARMv4/5, ARM7/ARM9,
4465 and ARM9TDMI commands.
4467 @deffn Command {arm966e cp15} regnum [value]
4468 Display cp15 register @var{regnum};
4469 else if a @var{value} is provided, that value is written to that register.
4472 @subsection XScale specific commands
4475 These commands are available to XScale based CPUs,
4476 which are implementations of the ARMv5TE architecture.
4478 @deffn Command {xscale analyze_trace}
4479 Displays the contents of the trace buffer.
4482 @deffn Command {xscale cache_clean_address} address
4483 Changes the address used when cleaning the data cache.
4486 @deffn Command {xscale cache_info}
4487 Displays information about the CPU caches.
4490 @deffn Command {xscale cp15} regnum [value]
4491 Display cp15 register @var{regnum};
4492 else if a @var{value} is provided, that value is written to that register.
4495 @deffn Command {xscale debug_handler} target address
4496 Changes the address used for the specified target's debug handler.
4499 @deffn Command {xscale dcache} (@option{enable}|@option{disable})
4500 Enables or disable the CPU's data cache.
4503 @deffn Command {xscale dump_trace} filename
4504 Dumps the raw contents of the trace buffer to @file{filename}.
4507 @deffn Command {xscale icache} (@option{enable}|@option{disable})
4508 Enables or disable the CPU's instruction cache.
4511 @deffn Command {xscale mmu} (@option{enable}|@option{disable})
4512 Enables or disable the CPU's memory management unit.
4515 @deffn Command {xscale trace_buffer} (@option{enable}|@option{disable}) [@option{fill} [n] | @option{wrap}]
4516 Enables or disables the trace buffer,
4517 and controls how it is emptied.
4520 @deffn Command {xscale trace_image} filename [offset [type]]
4521 Opens a trace image from @file{filename}, optionally rebasing
4522 its segment addresses by @var{offset}.
4523 The image @var{type} may be one of
4524 @option{bin} (binary), @option{ihex} (Intel hex),
4525 @option{elf} (ELF file), @option{s19} (Motorola s19),
4526 @option{mem}, or @option{builder}.
4529 @deffn Command {xscale vector_catch} mask
4530 Provide a bitmask showing the vectors to catch.
4533 @section ARMv6 Architecture
4536 @subsection ARM11 specific commands
4539 @deffn Command {arm11 mcr} p1 p2 p3 p4 p5
4540 Read coprocessor register
4543 @deffn Command {arm11 memwrite burst} [value]
4544 Displays the value of the memwrite burst-enable flag,
4545 which is enabled by default.
4546 If @var{value} is defined, first assigns that.
4549 @deffn Command {arm11 memwrite error_fatal} [value]
4550 Displays the value of the memwrite error_fatal flag,
4551 which is enabled by default.
4552 If @var{value} is defined, first assigns that.
4555 @deffn Command {arm11 mrc} p1 p2 p3 p4 p5 value
4556 Write coprocessor register
4559 @deffn Command {arm11 no_increment} [value]
4560 Displays the value of the flag controlling whether
4561 some read or write operations increment the pointer
4562 (the default behavior) or not (acting like a FIFO).
4563 If @var{value} is defined, first assigns that.
4566 @deffn Command {arm11 step_irq_enable} [value]
4567 Displays the value of the flag controlling whether
4568 IRQs are enabled during single stepping;
4569 they is disabled by default.
4570 If @var{value} is defined, first assigns that.
4573 @section ARMv7 Architecture
4576 @subsection ARMv7 Debug Access Port (DAP) specific commands
4577 @cindex Debug Access Port
4579 These commands are specific to ARM architecture v7 Debug Access Port (DAP),
4580 included on cortex-m3 and cortex-a8 systems.
4581 They are available in addition to other core-specific commands that may be available.
4583 @deffn Command {dap info} [num]
4584 Displays dap info for ap @var{num}, defaulting to the currently selected AP.
4587 @deffn Command {dap apsel} [num]
4588 Select AP @var{num}, defaulting to 0.
4591 @deffn Command {dap apid} [num]
4592 Displays id register from AP @var{num},
4593 defaulting to the currently selected AP.
4596 @deffn Command {dap baseaddr} [num]
4597 Displays debug base address from AP @var{num},
4598 defaulting to the currently selected AP.
4601 @deffn Command {dap memaccess} [value]
4602 Displays the number of extra tck for mem-ap memory bus access [0-255].
4603 If @var{value} is defined, first assigns that.
4606 @subsection Cortex-M3 specific commands
4609 @deffn Command {cortex_m3 maskisr} (@option{on}|@option{off})
4610 Control masking (disabling) interrupts during target step/resume.
4613 @section Target DCC Requests
4614 @cindex Linux-ARM DCC support
4617 OpenOCD can handle certain target requests; currently debugmsgs
4618 @command{target_request debugmsgs}
4619 are only supported for arm7_9 and cortex_m3.
4621 See libdcc in the contrib dir for more details.
4622 Linux-ARM kernels have a ``Kernel low-level debugging
4623 via EmbeddedICE DCC channel'' option (CONFIG_DEBUG_ICEDCC,
4624 depends on CONFIG_DEBUG_LL) which uses this mechanism to
4625 deliver messages before a serial console can be activated.
4627 @deffn Command {target_request debugmsgs} [@option{enable}|@option{disable}|@option{charmsg}]
4628 Displays current handling of target DCC message requests.
4629 These messages may be sent to the debugger while the target is running.
4630 The optional @option{enable} and @option{charmsg} parameters
4631 both enable the messages, while @option{disable} disables them.
4632 With @option{charmsg} the DCC words each contain one character,
4633 as used by Linux with CONFIG_DEBUG_ICEDCC;
4634 otherwise the libdcc format is used.
4638 @chapter JTAG Commands
4639 @cindex JTAG Commands
4640 Most general purpose JTAG commands have been presented earlier.
4641 (@xref{JTAG Speed}, @ref{Reset Configuration}, and @ref{TAP Declaration}.)
4642 Lower level JTAG commands, as presented here,
4643 may be needed to work with targets which require special
4644 attention during operations such as reset or initialization.
4646 To use these commands you will need to understand some
4647 of the basics of JTAG, including:
4650 @item A JTAG scan chain consists of a sequence of individual TAP
4651 devices such as a CPUs.
4652 @item Control operations involve moving each TAP through the same
4653 standard state machine (in parallel)
4654 using their shared TMS and clock signals.
4655 @item Data transfer involves shifting data through the chain of
4656 instruction or data registers of each TAP, writing new register values
4657 while the reading previous ones.
4658 @item Data register sizes are a function of the instruction active in
4659 a given TAP, while instruction register sizes are fixed for each TAP.
4660 All TAPs support a BYPASS instruction with a single bit data register.
4661 @item The way OpenOCD differentiates between TAP devices is by
4662 shifting different instructions into (and out of) their instruction
4666 @section Low Level JTAG Commands
4668 These commands are used by developers who need to access
4669 JTAG instruction or data registers, possibly controlling
4670 the order of TAP state transitions.
4671 If you're not debugging OpenOCD internals, or bringing up a
4672 new JTAG adapter or a new type of TAP device (like a CPU or
4673 JTAG router), you probably won't need to use these commands.
4675 @deffn Command {drscan} tap [numbits value]+ [@option{-endstate} tap_state]
4676 Loads the data register of @var{tap} with a series of bit fields
4677 that specify the entire register.
4678 Each field is @var{numbits} bits long with
4679 a numeric @var{value} (hexadecimal encouraged).
4680 The return value holds the original value of each
4683 For example, a 38 bit number might be specified as one
4684 field of 32 bits then one of 6 bits.
4685 @emph{For portability, never pass fields which are more
4686 than 32 bits long. Many OpenOCD implementations do not
4687 support 64-bit (or larger) integer values.}
4689 All TAPs other than @var{tap} must be in BYPASS mode.
4690 The single bit in their data registers does not matter.
4692 When @var{tap_state} is specified, the JTAG state machine is left
4694 For example @sc{drpause} might be specified, so that more
4695 instructions can be issued before re-entering the @sc{run/idle} state.
4696 If the end state is not specified, the @sc{run/idle} state is entered.
4699 OpenOCD does not record information about data register lengths,
4700 so @emph{it is important that you get the bit field lengths right}.
4701 Remember that different JTAG instructions refer to different
4702 data registers, which may have different lengths.
4703 Moreover, those lengths may not be fixed;
4704 the SCAN_N instruction can change the length of
4705 the register accessed by the INTEST instruction
4706 (by connecting a different scan chain).
4710 @deffn Command {flush_count}
4711 Returns the number of times the JTAG queue has been flushed.
4712 This may be used for performance tuning.
4714 For example, flushing a queue over USB involves a
4715 minimum latency, often several milliseconds, which does
4716 not change with the amount of data which is written.
4717 You may be able to identify performance problems by finding
4718 tasks which waste bandwidth by flushing small transfers too often,
4719 instead of batching them into larger operations.
4722 @deffn Command {irscan} [tap instruction]+ [@option{-endstate} tap_state]
4723 For each @var{tap} listed, loads the instruction register
4724 with its associated numeric @var{instruction}.
4725 (The number of bits in that instruction may be displayed
4726 using the @command{scan_chain} command.)
4727 For other TAPs, a BYPASS instruction is loaded.
4729 When @var{tap_state} is specified, the JTAG state machine is left
4731 For example @sc{irpause} might be specified, so the data register
4732 can be loaded before re-entering the @sc{run/idle} state.
4733 If the end state is not specified, the @sc{run/idle} state is entered.
4736 OpenOCD currently supports only a single field for instruction
4737 register values, unlike data register values.
4738 For TAPs where the instruction register length is more than 32 bits,
4739 portable scripts currently must issue only BYPASS instructions.
4743 @deffn Command {jtag_reset} trst srst
4744 Set values of reset signals.
4745 The @var{trst} and @var{srst} parameter values may be
4746 @option{0}, indicating that reset is inactive (pulled or driven high),
4747 or @option{1}, indicating it is active (pulled or driven low).
4748 The @command{reset_config} command should already have been used
4749 to configure how the board and JTAG adapter treat these two
4750 signals, and to say if either signal is even present.
4751 @xref{Reset Configuration}.
4754 @deffn Command {runtest} @var{num_cycles}
4755 Move to the @sc{run/idle} state, and execute at least
4756 @var{num_cycles} of the JTAG clock (TCK).
4757 Instructions often need some time
4758 to execute before they take effect.
4761 @deffn Command {scan_chain}
4762 Displays the TAPs in the scan chain configuration,
4764 The set of TAPs listed by this command is fixed by
4765 exiting the OpenOCD configuration stage,
4766 but systems with a JTAG router can
4767 enable or disable TAPs dynamically.
4768 In addition to the enable/disable status, the contents of
4769 each TAP's instruction register can also change.
4772 @c tms_sequence (short|long)
4773 @c ... temporary, debug-only, probably gone before 0.2 ships
4775 @deffn Command {verify_ircapture} (@option{enable}|@option{disable})
4776 Verify values captured during @sc{ircapture} and returned
4777 during IR scans. Default is enabled, but this can be
4778 overridden by @command{verify_jtag}.
4781 @deffn Command {verify_jtag} (@option{enable}|@option{disable})
4782 Enables verification of DR and IR scans, to help detect
4783 programming errors. For IR scans, @command{verify_ircapture}
4784 must also be enabled.
4788 @section TAP state names
4789 @cindex TAP state names
4791 The @var{tap_state} names used by OpenOCD in the @command{drscan},
4792 and @command{irscan} commands are:
4795 @item @b{RESET} ... should act as if TRST were active
4796 @item @b{RUN/IDLE} ... don't assume this always means IDLE
4799 @item @b{DRSHIFT} ... TDI/TDO shifting through the data register
4801 @item @b{DRPAUSE} ... data register ready for update or more shifting
4806 @item @b{IRSHIFT} ... TDI/TDO shifting through the instruction register
4808 @item @b{IRPAUSE} ... instruction register ready for update or more shifting
4813 Note that only six of those states are fully ``stable'' in the
4814 face of TMS fixed (usually low)
4815 and a free-running JTAG clock. For all the
4816 others, the next TCK transition changes to a new state.
4819 @item From @sc{drshift} and @sc{irshift}, clock transitions will
4820 produce side effects by changing register contents. The values
4821 to be latched in upcoming @sc{drupdate} or @sc{irupdate} states
4822 may not be as expected.
4823 @item @sc{run/idle}, @sc{drpause}, and @sc{irpause} are reasonable
4824 choices after @command{drscan} or @command{irscan} commands,
4825 since they are free of JTAG side effects.
4826 However, @sc{run/idle} may have side effects that appear at other
4827 levels, such as advancing the ARM9E-S instruction pipeline.
4828 Consult the documentation for the TAP(s) you are working with.
4834 If OpenOCD runs on an embedded host(as ZY1000 does), then TFTP can
4835 be used to access files on PCs (either the developer's PC or some other PC).
4837 The way this works on the ZY1000 is to prefix a filename by
4838 "/tftp/ip/" and append the TFTP path on the TFTP
4839 server (tftpd). For example,
4842 load_image /tftp/10.0.0.96/c:\temp\abc.elf
4845 will load c:\temp\abc.elf from the developer pc (10.0.0.96) into memory as
4846 if the file was hosted on the embedded host.
4848 In order to achieve decent performance, you must choose a TFTP server
4849 that supports a packet size bigger than the default packet size (512 bytes). There
4850 are numerous TFTP servers out there (free and commercial) and you will have to do
4851 a bit of googling to find something that fits your requirements.
4853 @node Sample Scripts
4854 @chapter Sample Scripts
4857 This page shows how to use the Target Library.
4859 The configuration script can be divided into the following sections:
4861 @item Daemon configuration
4863 @item JTAG scan chain
4864 @item Target configuration
4865 @item Flash configuration
4868 Detailed information about each section can be found at OpenOCD configuration.
4870 @section AT91R40008 example
4871 @cindex AT91R40008 example
4872 To start OpenOCD with a target script for the AT91R40008 CPU and reset
4873 the CPU upon startup of the OpenOCD daemon.
4875 openocd -f interface/parport.cfg -f target/at91r40008.cfg \
4876 -c "init" -c "reset"
4880 @node GDB and OpenOCD
4881 @chapter GDB and OpenOCD
4883 OpenOCD complies with the remote gdbserver protocol, and as such can be used
4884 to debug remote targets.
4886 @anchor{Connecting to GDB}
4887 @section Connecting to GDB
4888 @cindex Connecting to GDB
4889 Use GDB 6.7 or newer with OpenOCD if you run into trouble. For
4890 instance GDB 6.3 has a known bug that produces bogus memory access
4891 errors, which has since been fixed: look up 1836 in
4892 @url{http://sourceware.org/cgi-bin/gnatsweb.pl?database=gdb}
4894 OpenOCD can communicate with GDB in two ways:
4898 A socket (TCP/IP) connection is typically started as follows:
4900 target remote localhost:3333
4902 This would cause GDB to connect to the gdbserver on the local pc using port 3333.
4904 A pipe connection is typically started as follows:
4906 target remote | openocd --pipe
4908 This would cause GDB to run OpenOCD and communicate using pipes (stdin/stdout).
4909 Using this method has the advantage of GDB starting/stopping OpenOCD for the debug
4913 To list the available OpenOCD commands type @command{monitor help} on the
4916 OpenOCD supports the gdb @option{qSupported} packet, this enables information
4917 to be sent by the GDB remote server (i.e. OpenOCD) to GDB. Typical information includes
4918 packet size and the device's memory map.
4920 Previous versions of OpenOCD required the following GDB options to increase
4921 the packet size and speed up GDB communication:
4923 set remote memory-write-packet-size 1024
4924 set remote memory-write-packet-size fixed
4925 set remote memory-read-packet-size 1024
4926 set remote memory-read-packet-size fixed
4928 This is now handled in the @option{qSupported} PacketSize and should not be required.
4930 @section Programming using GDB
4931 @cindex Programming using GDB
4933 By default the target memory map is sent to GDB. This can be disabled by
4934 the following OpenOCD configuration option:
4936 gdb_memory_map disable
4938 For this to function correctly a valid flash configuration must also be set
4939 in OpenOCD. For faster performance you should also configure a valid
4942 Informing GDB of the memory map of the target will enable GDB to protect any
4943 flash areas of the target and use hardware breakpoints by default. This means
4944 that the OpenOCD option @command{gdb_breakpoint_override} is not required when
4945 using a memory map. @xref{gdb_breakpoint_override}.
4947 To view the configured memory map in GDB, use the GDB command @option{info mem}
4948 All other unassigned addresses within GDB are treated as RAM.
4950 GDB 6.8 and higher set any memory area not in the memory map as inaccessible.
4951 This can be changed to the old behaviour by using the following GDB command
4953 set mem inaccessible-by-default off
4956 If @command{gdb_flash_program enable} is also used, GDB will be able to
4957 program any flash memory using the vFlash interface.
4959 GDB will look at the target memory map when a load command is given, if any
4960 areas to be programmed lie within the target flash area the vFlash packets
4963 If the target needs configuring before GDB programming, an event
4964 script can be executed:
4966 $_TARGETNAME configure -event EVENTNAME BODY
4969 To verify any flash programming the GDB command @option{compare-sections}
4972 @node Tcl Scripting API
4973 @chapter Tcl Scripting API
4974 @cindex Tcl Scripting API
4978 The commands are stateless. E.g. the telnet command line has a concept
4979 of currently active target, the Tcl API proc's take this sort of state
4980 information as an argument to each proc.
4982 There are three main types of return values: single value, name value
4983 pair list and lists.
4985 Name value pair. The proc 'foo' below returns a name/value pair
4991 > set foo(you) Oyvind
4992 > set foo(mouse) Micky
4993 > set foo(duck) Donald
5001 me Duane you Oyvind mouse Micky duck Donald
5003 Thus, to get the names of the associative array is easy:
5005 foreach { name value } [set foo] {
5006 puts "Name: $name, Value: $value"
5010 Lists returned must be relatively small. Otherwise a range
5011 should be passed in to the proc in question.
5013 @section Internal low-level Commands
5015 By low-level, the intent is a human would not directly use these commands.
5017 Low-level commands are (should be) prefixed with "ocd_", e.g.
5018 @command{ocd_flash_banks}
5019 is the low level API upon which @command{flash banks} is implemented.
5022 @item @b{ocd_mem2array} <@var{varname}> <@var{width}> <@var{addr}> <@var{nelems}>
5024 Read memory and return as a Tcl array for script processing
5025 @item @b{ocd_array2mem} <@var{varname}> <@var{width}> <@var{addr}> <@var{nelems}>
5027 Convert a Tcl array to memory locations and write the values
5028 @item @b{ocd_flash_banks} <@var{driver}> <@var{base}> <@var{size}> <@var{chip_width}> <@var{bus_width}> <@var{target}> [@option{driver options} ...]
5030 Return information about the flash banks
5033 OpenOCD commands can consist of two words, e.g. "flash banks". The
5034 startup.tcl "unknown" proc will translate this into a Tcl proc
5035 called "flash_banks".
5037 @section OpenOCD specific Global Variables
5041 Real Tcl has ::tcl_platform(), and platform::identify, and many other
5042 variables. JimTCL, as implemented in OpenOCD creates $HostOS which
5043 holds one of the following values:
5046 @item @b{winxx} Built using Microsoft Visual Studio
5047 @item @b{linux} Linux is the underlying operating sytem
5048 @item @b{darwin} Darwin (mac-os) is the underlying operating sytem.
5049 @item @b{cygwin} Running under Cygwin
5050 @item @b{mingw32} Running under MingW32
5051 @item @b{other} Unknown, none of the above.
5054 Note: 'winxx' was choosen because today (March-2009) no distinction is made between Win32 and Win64.
5057 We should add support for a variable like Tcl variable
5058 @code{tcl_platform(platform)}, it should be called
5059 @code{jim_platform} (because it
5060 is jim, not real tcl).
5064 @chapter Deprecated/Removed Commands
5065 @cindex Deprecated/Removed Commands
5066 Certain OpenOCD commands have been deprecated or
5067 removed during the various revisions.
5069 Upgrade your scripts as soon as possible.
5070 These descriptions for old commands may be removed
5071 a year after the command itself was removed.
5072 This means that in January 2010 this chapter may
5073 become much shorter.
5076 @item @b{arm7_9 fast_writes}
5077 @cindex arm7_9 fast_writes
5078 @*Use @command{arm7_9 fast_memory_access} instead.
5081 @*An buggy old command that would not really work since background polling would wipe out the global endstate
5082 @xref{arm7_9 fast_memory_access}.
5083 @item @b{arm7_9 force_hw_bkpts}
5084 @*Use @command{gdb_breakpoint_override} instead. Note that GDB will use hardware breakpoints
5085 for flash if the GDB memory map has been set up(default when flash is declared in
5086 target configuration). @xref{gdb_breakpoint_override}.
5087 @item @b{arm7_9 sw_bkpts}
5088 @*On by default. @xref{gdb_breakpoint_override}.
5089 @item @b{daemon_startup}
5090 @*this config option has been removed, simply adding @option{init} and @option{reset halt} to
5091 the end of your config script will give the same behaviour as using @option{daemon_startup reset}
5092 and @option{target cortex_m3 little reset_halt 0}.
5093 @item @b{dump_binary}
5094 @*use @option{dump_image} command with same args. @xref{dump_image}.
5095 @item @b{flash erase}
5096 @*use @option{flash erase_sector} command with same args. @xref{flash erase_sector}.
5097 @item @b{flash write}
5098 @*use @option{flash write_bank} command with same args. @xref{flash write_bank}.
5099 @item @b{flash write_binary}
5100 @*use @option{flash write_bank} command with same args. @xref{flash write_bank}.
5101 @item @b{flash auto_erase}
5102 @*use @option{flash write_image} command passing @option{erase} as the first parameter. @xref{flash write_image}.
5104 @item @b{jtag_device}
5105 @*use the @command{jtag newtap} command, converting from positional syntax
5106 to named prefixes, and naming the TAP.
5108 Note that if you try to use the old command, a message will tell you the
5109 right new command to use; and that the fourth parameter in the old syntax
5110 was never actually used.
5112 OLD: jtag_device 8 0x01 0xe3 0xfe
5113 NEW: jtag newtap CHIPNAME TAPNAME \
5114 -irlen 8 -ircapture 0x01 -irmask 0xe3
5117 @item @b{jtag_speed} value
5118 @*@xref{JTAG Speed}.
5119 Usually, a value of zero means maximum
5120 speed. The actual effect of this option depends on the JTAG interface used.
5122 @item wiggler: maximum speed / @var{number}
5123 @item ft2232: 6MHz / (@var{number}+1)
5124 @item amt jtagaccel: 8 / 2**@var{number}
5125 @item jlink: maximum speed in kHz (0-12000), 0 will use RTCK
5126 @item rlink: 24MHz / @var{number}, but only for certain values of @var{number}
5127 @comment end speed list.
5130 @item @b{load_binary}
5131 @*use @option{load_image} command with same args. @xref{load_image}.
5132 @item @b{run_and_halt_time}
5133 @*This command has been removed for simpler reset behaviour, it can be simulated with the
5140 @item @b{target} <@var{type}> <@var{endian}> <@var{jtag-position}>
5141 @*use the create subcommand of @option{target}.
5142 @item @b{target_script} <@var{target#}> <@var{eventname}> <@var{scriptname}>
5143 @*use <@var{target_name}> configure -event <@var{eventname}> "script <@var{scriptname}>"
5144 @item @b{working_area}
5145 @*use the @option{configure} subcommand of @option{target} to set the work-area-virt, work-area-phy, work-area-size, and work-area-backup properties of the target.
5153 @item @b{RTCK, also known as: Adaptive Clocking - What is it?}
5155 @cindex adaptive clocking
5158 In digital circuit design it is often refered to as ``clock
5159 synchronisation'' the JTAG interface uses one clock (TCK or TCLK)
5160 operating at some speed, your target is operating at another. The two
5161 clocks are not synchronised, they are ``asynchronous''
5163 In order for the two to work together they must be synchronised. Otherwise
5164 the two systems will get out of sync with each other and nothing will
5165 work. There are 2 basic options:
5168 Use a special circuit.
5170 One clock must be some multiple slower than the other.
5173 @b{Does this really matter?} For some chips and some situations, this
5174 is a non-issue (i.e.: A 500MHz ARM926) but for others - for example some
5175 Atmel SAM7 and SAM9 chips start operation from reset at 32kHz -
5176 program/enable the oscillators and eventually the main clock. It is in
5177 those critical times you must slow the JTAG clock to sometimes 1 to
5180 Imagine debugging a 500MHz ARM926 hand held battery powered device
5181 that ``deep sleeps'' at 32kHz between every keystroke. It can be
5184 @b{Solution #1 - A special circuit}
5186 In order to make use of this, your JTAG dongle must support the RTCK
5187 feature. Not all dongles support this - keep reading!
5189 The RTCK signal often found in some ARM chips is used to help with
5190 this problem. ARM has a good description of the problem described at
5191 this link: @url{http://www.arm.com/support/faqdev/4170.html} [checked
5192 28/nov/2008]. Link title: ``How does the JTAG synchronisation logic
5193 work? / how does adaptive clocking work?''.
5195 The nice thing about adaptive clocking is that ``battery powered hand
5196 held device example'' - the adaptiveness works perfectly all the
5197 time. One can set a break point or halt the system in the deep power
5198 down code, slow step out until the system speeds up.
5200 @b{Solution #2 - Always works - but may be slower}
5202 Often this is a perfectly acceptable solution.
5204 In most simple terms: Often the JTAG clock must be 1/10 to 1/12 of
5205 the target clock speed. But what that ``magic division'' is varies
5206 depending on the chips on your board. @b{ARM rule of thumb} Most ARM
5207 based systems require an 8:1 division. @b{Xilinx rule of thumb} is
5208 1/12 the clock speed.
5210 Note: Many FTDI2232C based JTAG dongles are limited to 6MHz.
5212 You can still debug the 'low power' situations - you just need to
5213 manually adjust the clock speed at every step. While painful and
5214 tedious, it is not always practical.
5216 It is however easy to ``code your way around it'' - i.e.: Cheat a little,
5217 have a special debug mode in your application that does a ``high power
5218 sleep''. If you are careful - 98% of your problems can be debugged
5221 To set the JTAG frequency use the command:
5229 @item @b{Win32 Pathnames} Why don't backslashes work in Windows paths?
5231 OpenOCD uses Tcl and a backslash is an escape char. Use @{ and @}
5232 around Windows filenames.
5245 @item @b{Missing: cygwin1.dll} OpenOCD complains about a missing cygwin1.dll.
5247 Make sure you have Cygwin installed, or at least a version of OpenOCD that
5248 claims to come with all the necessary DLLs. When using Cygwin, try launching
5249 OpenOCD from the Cygwin shell.
5251 @item @b{Breakpoint Issue} I'm trying to set a breakpoint using GDB (or a frontend like Insight or
5252 Eclipse), but OpenOCD complains that "Info: arm7_9_common.c:213
5253 arm7_9_add_breakpoint(): sw breakpoint requested, but software breakpoints not enabled".
5255 GDB issues software breakpoints when a normal breakpoint is requested, or to implement
5256 source-line single-stepping. On ARMv4T systems, like ARM7TDMI, ARM720T or ARM920T,
5257 software breakpoints consume one of the two available hardware breakpoints.
5259 @item @b{LPC2000 Flash} When erasing or writing LPC2000 on-chip flash, the operation fails at random.
5261 Make sure the core frequency specified in the @option{flash lpc2000} line matches the
5262 clock at the time you're programming the flash. If you've specified the crystal's
5263 frequency, make sure the PLL is disabled. If you've specified the full core speed
5264 (e.g. 60MHz), make sure the PLL is enabled.
5266 @item @b{Amontec Chameleon} When debugging using an Amontec Chameleon in its JTAG Accelerator configuration,
5267 I keep getting "Error: amt_jtagaccel.c:184 amt_wait_scan_busy(): amt_jtagaccel timed
5268 out while waiting for end of scan, rtck was disabled".
5270 Make sure your PC's parallel port operates in EPP mode. You might have to try several
5271 settings in your PC BIOS (ECP, EPP, and different versions of those).
5273 @item @b{Data Aborts} When debugging with OpenOCD and GDB (plain GDB, Insight, or Eclipse),
5274 I get lots of "Error: arm7_9_common.c:1771 arm7_9_read_memory():
5275 memory read caused data abort".
5277 The errors are non-fatal, and are the result of GDB trying to trace stack frames
5278 beyond the last valid frame. It might be possible to prevent this by setting up
5279 a proper "initial" stack frame, if you happen to know what exactly has to
5280 be done, feel free to add this here.
5282 @b{Simple:} In your startup code - push 8 registers of zeros onto the
5283 stack before calling main(). What GDB is doing is ``climbing'' the run
5284 time stack by reading various values on the stack using the standard
5285 call frame for the target. GDB keeps going - until one of 2 things
5286 happen @b{#1} an invalid frame is found, or @b{#2} some huge number of
5287 stackframes have been processed. By pushing zeros on the stack, GDB
5290 @b{Debugging Interrupt Service Routines} - In your ISR before you call
5291 your C code, do the same - artifically push some zeros onto the stack,
5292 remember to pop them off when the ISR is done.
5294 @b{Also note:} If you have a multi-threaded operating system, they
5295 often do not @b{in the intrest of saving memory} waste these few
5299 @item @b{JTAG Reset Config} I get the following message in the OpenOCD console (or log file):
5300 "Warning: arm7_9_common.c:679 arm7_9_assert_reset(): srst resets test logic, too".
5302 This warning doesn't indicate any serious problem, as long as you don't want to
5303 debug your core right out of reset. Your .cfg file specified @option{jtag_reset
5304 trst_and_srst srst_pulls_trst} to tell OpenOCD that either your board,
5305 your debugger or your target uC (e.g. LPC2000) can't assert the two reset signals
5306 independently. With this setup, it's not possible to halt the core right out of
5307 reset, everything else should work fine.
5309 @item @b{USB Power} When using OpenOCD in conjunction with Amontec JTAGkey and the Yagarto
5310 toolchain (Eclipse, arm-elf-gcc, arm-elf-gdb), the debugging seems to be
5311 unstable. When single-stepping over large blocks of code, GDB and OpenOCD
5312 quit with an error message. Is there a stability issue with OpenOCD?
5314 No, this is not a stability issue concerning OpenOCD. Most users have solved
5315 this issue by simply using a self-powered USB hub, which they connect their
5316 Amontec JTAGkey to. Apparently, some computers do not provide a USB power
5317 supply stable enough for the Amontec JTAGkey to be operated.
5319 @b{Laptops running on battery have this problem too...}
5321 @item @b{USB Power} When using the Amontec JTAGkey, sometimes OpenOCD crashes with the
5322 following error messages: "Error: ft2232.c:201 ft2232_read(): FT_Read returned:
5323 4" and "Error: ft2232.c:365 ft2232_send_and_recv(): couldn't read from FT2232".
5324 What does that mean and what might be the reason for this?
5326 First of all, the reason might be the USB power supply. Try using a self-powered
5327 hub instead of a direct connection to your computer. Secondly, the error code 4
5328 corresponds to an FT_IO_ERROR, which means that the driver for the FTDI USB
5329 chip ran into some sort of error - this points us to a USB problem.
5331 @item @b{GDB Disconnects} When using the Amontec JTAGkey, sometimes OpenOCD crashes with the following
5332 error message: "Error: gdb_server.c:101 gdb_get_char(): read: 10054".
5333 What does that mean and what might be the reason for this?
5335 Error code 10054 corresponds to WSAECONNRESET, which means that the debugger (GDB)
5336 has closed the connection to OpenOCD. This might be a GDB issue.
5338 @item @b{LPC2000 Flash} In the configuration file in the section where flash device configurations
5339 are described, there is a parameter for specifying the clock frequency
5340 for LPC2000 internal flash devices (e.g. @option{flash bank lpc2000
5341 0x0 0x40000 0 0 0 lpc2000_v1 14746 calc_checksum}), which must be
5342 specified in kilohertz. However, I do have a quartz crystal of a
5343 frequency that contains fractions of kilohertz (e.g. 14,745,600 Hz,
5344 i.e. 14,745.600 kHz). Is it possible to specify real numbers for the
5347 No. The clock frequency specified here must be given as an integral number.
5348 However, this clock frequency is used by the In-Application-Programming (IAP)
5349 routines of the LPC2000 family only, which seems to be very tolerant concerning
5350 the given clock frequency, so a slight difference between the specified clock
5351 frequency and the actual clock frequency will not cause any trouble.
5353 @item @b{Command Order} Do I have to keep a specific order for the commands in the configuration file?
5355 Well, yes and no. Commands can be given in arbitrary order, yet the
5356 devices listed for the JTAG scan chain must be given in the right
5357 order (jtag newdevice), with the device closest to the TDO-Pin being
5358 listed first. In general, whenever objects of the same type exist
5359 which require an index number, then these objects must be given in the
5360 right order (jtag newtap, targets and flash banks - a target
5361 references a jtag newtap and a flash bank references a target).
5363 You can use the ``scan_chain'' command to verify and display the tap order.
5365 Also, some commands can't execute until after @command{init} has been
5366 processed. Such commands include @command{nand probe} and everything
5367 else that needs to write to controller registers, perhaps for setting
5368 up DRAM and loading it with code.
5370 @anchor{FAQ TAP Order}
5371 @item @b{JTAG TAP Order} Do I have to declare the TAPS in some
5374 Yes; whenever you have more than one, you must declare them in
5375 the same order used by the hardware.
5377 Many newer devices have multiple JTAG TAPs. For example: ST
5378 Microsystems STM32 chips have two TAPs, a ``boundary scan TAP'' and
5379 ``Cortex-M3'' TAP. Example: The STM32 reference manual, Document ID:
5380 RM0008, Section 26.5, Figure 259, page 651/681, the ``TDI'' pin is
5381 connected to the boundary scan TAP, which then connects to the
5382 Cortex-M3 TAP, which then connects to the TDO pin.
5384 Thus, the proper order for the STM32 chip is: (1) The Cortex-M3, then
5385 (2) The boundary scan TAP. If your board includes an additional JTAG
5386 chip in the scan chain (for example a Xilinx CPLD or FPGA) you could
5387 place it before or after the STM32 chip in the chain. For example:
5390 @item OpenOCD_TDI(output) -> STM32 TDI Pin (BS Input)
5391 @item STM32 BS TDO (output) -> STM32 Cortex-M3 TDI (input)
5392 @item STM32 Cortex-M3 TDO (output) -> SM32 TDO Pin
5393 @item STM32 TDO Pin (output) -> Xilinx TDI Pin (input)
5394 @item Xilinx TDO Pin -> OpenOCD TDO (input)
5397 The ``jtag device'' commands would thus be in the order shown below. Note:
5400 @item jtag newtap Xilinx tap -irlen ...
5401 @item jtag newtap stm32 cpu -irlen ...
5402 @item jtag newtap stm32 bs -irlen ...
5403 @item # Create the debug target and say where it is
5404 @item target create stm32.cpu -chain-position stm32.cpu ...
5408 @item @b{SYSCOMP} Sometimes my debugging session terminates with an error. When I look into the
5409 log file, I can see these error messages: Error: arm7_9_common.c:561
5410 arm7_9_execute_sys_speed(): timeout waiting for SYSCOMP
5416 @node Tcl Crash Course
5417 @chapter Tcl Crash Course
5420 Not everyone knows Tcl - this is not intended to be a replacement for
5421 learning Tcl, the intent of this chapter is to give you some idea of
5422 how the Tcl scripts work.
5424 This chapter is written with two audiences in mind. (1) OpenOCD users
5425 who need to understand a bit more of how JIM-Tcl works so they can do
5426 something useful, and (2) those that want to add a new command to
5429 @section Tcl Rule #1
5430 There is a famous joke, it goes like this:
5432 @item Rule #1: The wife is always correct
5433 @item Rule #2: If you think otherwise, See Rule #1
5436 The Tcl equal is this:
5439 @item Rule #1: Everything is a string
5440 @item Rule #2: If you think otherwise, See Rule #1
5443 As in the famous joke, the consequences of Rule #1 are profound. Once
5444 you understand Rule #1, you will understand Tcl.
5446 @section Tcl Rule #1b
5447 There is a second pair of rules.
5449 @item Rule #1: Control flow does not exist. Only commands
5450 @* For example: the classic FOR loop or IF statement is not a control
5451 flow item, they are commands, there is no such thing as control flow
5453 @item Rule #2: If you think otherwise, See Rule #1
5454 @* Actually what happens is this: There are commands that by
5455 convention, act like control flow key words in other languages. One of
5456 those commands is the word ``for'', another command is ``if''.
5459 @section Per Rule #1 - All Results are strings
5460 Every Tcl command results in a string. The word ``result'' is used
5461 deliberatly. No result is just an empty string. Remember: @i{Rule #1 -
5462 Everything is a string}
5464 @section Tcl Quoting Operators
5465 In life of a Tcl script, there are two important periods of time, the
5466 difference is subtle.
5469 @item Evaluation Time
5472 The two key items here are how ``quoted things'' work in Tcl. Tcl has
5473 three primary quoting constructs, the [square-brackets] the
5474 @{curly-braces@} and ``double-quotes''
5476 By now you should know $VARIABLES always start with a $DOLLAR
5477 sign. BTW: To set a variable, you actually use the command ``set'', as
5478 in ``set VARNAME VALUE'' much like the ancient BASIC langauge ``let x
5479 = 1'' statement, but without the equal sign.
5482 @item @b{[square-brackets]}
5483 @* @b{[square-brackets]} are command substitutions. It operates much
5484 like Unix Shell `back-ticks`. The result of a [square-bracket]
5485 operation is exactly 1 string. @i{Remember Rule #1 - Everything is a
5486 string}. These two statements are roughly identical:
5490 echo "The Date is: $X"
5493 puts "The Date is: $X"
5495 @item @b{``double-quoted-things''}
5496 @* @b{``double-quoted-things''} are just simply quoted
5497 text. $VARIABLES and [square-brackets] are expanded in place - the
5498 result however is exactly 1 string. @i{Remember Rule #1 - Everything
5502 puts "It is now \"[date]\", $x is in 1 hour"
5504 @item @b{@{Curly-Braces@}}
5505 @*@b{@{Curly-Braces@}} are magic: $VARIABLES and [square-brackets] are
5506 parsed, but are NOT expanded or executed. @{Curly-Braces@} are like
5507 'single-quote' operators in BASH shell scripts, with the added
5508 feature: @{curly-braces@} can be nested, single quotes can not. @{@{@{this is
5509 nested 3 times@}@}@} NOTE: [date] is perhaps a bad example, as of
5510 28/nov/2008, Jim/OpenOCD does not have a date command.
5513 @section Consequences of Rule 1/2/3/4
5515 The consequences of Rule 1 are profound.
5517 @subsection Tokenisation & Execution.
5519 Of course, whitespace, blank lines and #comment lines are handled in
5522 As a script is parsed, each (multi) line in the script file is
5523 tokenised and according to the quoting rules. After tokenisation, that
5524 line is immedatly executed.
5526 Multi line statements end with one or more ``still-open''
5527 @{curly-braces@} which - eventually - closes a few lines later.
5529 @subsection Command Execution
5531 Remember earlier: There are no ``control flow''
5532 statements in Tcl. Instead there are COMMANDS that simply act like
5533 control flow operators.
5535 Commands are executed like this:
5538 @item Parse the next line into (argc) and (argv[]).
5539 @item Look up (argv[0]) in a table and call its function.
5540 @item Repeat until End Of File.
5543 It sort of works like this:
5546 ReadAndParse( &argc, &argv );
5548 cmdPtr = LookupCommand( argv[0] );
5550 (*cmdPtr->Execute)( argc, argv );
5554 When the command ``proc'' is parsed (which creates a procedure
5555 function) it gets 3 parameters on the command line. @b{1} the name of
5556 the proc (function), @b{2} the list of parameters, and @b{3} the body
5557 of the function. Not the choice of words: LIST and BODY. The PROC
5558 command stores these items in a table somewhere so it can be found by
5561 @subsection The FOR command
5563 The most interesting command to look at is the FOR command. In Tcl,
5564 the FOR command is normally implemented in C. Remember, FOR is a
5565 command just like any other command.
5567 When the ascii text containing the FOR command is parsed, the parser
5568 produces 5 parameter strings, @i{(If in doubt: Refer to Rule #1)} they
5572 @item The ascii text 'for'
5573 @item The start text
5574 @item The test expression
5579 Sort of reminds you of ``main( int argc, char **argv )'' does it not?
5580 Remember @i{Rule #1 - Everything is a string.} The key point is this:
5581 Often many of those parameters are in @{curly-braces@} - thus the
5582 variables inside are not expanded or replaced until later.
5584 Remember that every Tcl command looks like the classic ``main( argc,
5585 argv )'' function in C. In JimTCL - they actually look like this:
5589 MyCommand( Jim_Interp *interp,
5591 Jim_Obj * const *argvs );
5594 Real Tcl is nearly identical. Although the newer versions have
5595 introduced a byte-code parser and intepreter, but at the core, it
5596 still operates in the same basic way.
5598 @subsection FOR command implementation
5600 To understand Tcl it is perhaps most helpful to see the FOR
5601 command. Remember, it is a COMMAND not a control flow structure.
5603 In Tcl there are two underlying C helper functions.
5605 Remember Rule #1 - You are a string.
5607 The @b{first} helper parses and executes commands found in an ascii
5608 string. Commands can be seperated by semicolons, or newlines. While
5609 parsing, variables are expanded via the quoting rules.
5611 The @b{second} helper evaluates an ascii string as a numerical
5612 expression and returns a value.
5614 Here is an example of how the @b{FOR} command could be
5615 implemented. The pseudo code below does not show error handling.
5617 void Execute_AsciiString( void *interp, const char *string );
5619 int Evaluate_AsciiExpression( void *interp, const char *string );
5622 MyForCommand( void *interp,
5627 SetResult( interp, "WRONG number of parameters");
5631 // argv[0] = the ascii string just like C
5633 // Execute the start statement.
5634 Execute_AsciiString( interp, argv[1] );
5638 i = Evaluate_AsciiExpression(interp, argv[2]);
5643 Execute_AsciiString( interp, argv[3] );
5645 // Execute the LOOP part
5646 Execute_AsciiString( interp, argv[4] );
5650 SetResult( interp, "" );
5655 Every other command IF, WHILE, FORMAT, PUTS, EXPR, everything works
5656 in the same basic way.
5658 @section OpenOCD Tcl Usage
5660 @subsection source and find commands
5661 @b{Where:} In many configuration files
5662 @* Example: @b{ source [find FILENAME] }
5663 @*Remember the parsing rules
5665 @item The FIND command is in square brackets.
5666 @* The FIND command is executed with the parameter FILENAME. It should
5667 find the full path to the named file. The RESULT is a string, which is
5668 substituted on the orginal command line.
5669 @item The command source is executed with the resulting filename.
5670 @* SOURCE reads a file and executes as a script.
5672 @subsection format command
5673 @b{Where:} Generally occurs in numerous places.
5674 @* Tcl has no command like @b{printf()}, instead it has @b{format}, which is really more like
5680 puts [format "The answer: %d" [expr $x * $y]]
5683 @item The SET command creates 2 variables, X and Y.
5684 @item The double [nested] EXPR command performs math
5685 @* The EXPR command produces numerical result as a string.
5687 @item The format command is executed, producing a single string
5688 @* Refer to Rule #1.
5689 @item The PUTS command outputs the text.
5691 @subsection Body or Inlined Text
5692 @b{Where:} Various TARGET scripts.
5695 proc someproc @{@} @{
5696 ... multiple lines of stuff ...
5698 $_TARGETNAME configure -event FOO someproc
5699 #2 Good - no variables
5700 $_TARGETNAME confgure -event foo "this ; that;"
5701 #3 Good Curly Braces
5702 $_TARGETNAME configure -event FOO @{
5705 #4 DANGER DANGER DANGER
5706 $_TARGETNAME configure -event foo "puts \"Time: [date]\""
5709 @item The $_TARGETNAME is an OpenOCD variable convention.
5710 @*@b{$_TARGETNAME} represents the last target created, the value changes
5711 each time a new target is created. Remember the parsing rules. When
5712 the ascii text is parsed, the @b{$_TARGETNAME} becomes a simple string,
5713 the name of the target which happens to be a TARGET (object)
5715 @item The 2nd parameter to the @option{-event} parameter is a TCBODY
5716 @*There are 4 examples:
5718 @item The TCLBODY is a simple string that happens to be a proc name
5719 @item The TCLBODY is several simple commands seperated by semicolons
5720 @item The TCLBODY is a multi-line @{curly-brace@} quoted string
5721 @item The TCLBODY is a string with variables that get expanded.
5724 In the end, when the target event FOO occurs the TCLBODY is
5725 evaluated. Method @b{#1} and @b{#2} are functionally identical. For
5726 Method @b{#3} and @b{#4} it is more interesting. What is the TCLBODY?
5728 Remember the parsing rules. In case #3, @{curly-braces@} mean the
5729 $VARS and [square-brackets] are expanded later, when the EVENT occurs,
5730 and the text is evaluated. In case #4, they are replaced before the
5731 ``Target Object Command'' is executed. This occurs at the same time
5732 $_TARGETNAME is replaced. In case #4 the date will never
5733 change. @{BTW: [date] is perhaps a bad example, as of 28/nov/2008,
5734 Jim/OpenOCD does not have a date command@}
5736 @subsection Global Variables
5737 @b{Where:} You might discover this when writing your own procs @* In
5738 simple terms: Inside a PROC, if you need to access a global variable
5739 you must say so. See also ``upvar''. Example:
5741 proc myproc @{ @} @{
5742 set y 0 #Local variable Y
5743 global x #Global variable X
5744 puts [format "X=%d, Y=%d" $x $y]
5747 @section Other Tcl Hacks
5748 @b{Dynamic variable creation}
5750 # Dynamically create a bunch of variables.
5751 for @{ set x 0 @} @{ $x < 32 @} @{ set x [expr $x + 1]@} @{
5753 set vn [format "BIT%d" $x]
5757 set $vn [expr (1 << $x)]
5760 @b{Dynamic proc/command creation}
5762 # One "X" function - 5 uart functions.
5763 foreach who @{A B C D E@}
5764 proc [format "show_uart%c" $who] @{ @} "show_UARTx $who"
5768 @node Target Library
5769 @chapter Target Library
5770 @cindex Target Library
5772 OpenOCD comes with a target configuration script library. These scripts can be
5773 used as-is or serve as a starting point.
5775 The target library is published together with the OpenOCD executable and
5776 the path to the target library is in the OpenOCD script search path.
5777 Similarly there are example scripts for configuring the JTAG interface.
5779 The command line below uses the example parport configuration script
5780 that ship with OpenOCD, then configures the str710.cfg target and
5781 finally issues the init and reset commands. The communication speed
5782 is set to 10kHz for reset and 8MHz for post reset.
5785 openocd -f interface/parport.cfg -f target/str710.cfg \
5786 -c "init" -c "reset"
5789 To list the target scripts available:
5792 $ ls /usr/local/lib/openocd/target
5794 arm7_fast.cfg lm3s6965.cfg pxa255.cfg stm32.cfg xba_revA3.cfg
5795 at91eb40a.cfg lpc2148.cfg pxa255_sst.cfg str710.cfg zy1000.cfg
5796 at91r40008.cfg lpc2294.cfg sam7s256.cfg str912.cfg
5797 at91sam9260.cfg nslu2.cfg sam7x256.cfg wi-9c.cfg
5802 @node OpenOCD Concept Index
5803 @comment DO NOT use the plain word ``Index'', reason: CYGWIN filename
5804 @comment case issue with ``Index.html'' and ``index.html''
5805 @comment Occurs when creating ``--html --no-split'' output
5806 @comment This fix is based on: http://sourceware.org/ml/binutils/2006-05/msg00215.html
5807 @unnumbered OpenOCD Concept Index
5811 @node Command and Driver Index
5812 @unnumbered Command and Driver Index