JTAG instructions and hints
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Contents
Introduction
TODO: Add generic info about JTAG and why it safes ones ass if he messes with the flash
Hardware
PPC-based-boxes
JTAG-cable from tampakuro/kuroguy
JTAG10-jtag-cable from http://www.soc-machines.com/
LS1
TODO: Add info about the additional Hardware mods needed to make JTAG working. Hint: bridge! + needed info about Flash structure
HG/HS
1) Installing headers TODO: what needs to be bridged?
Terastation
TODO: add specific Info if additional hardware mods are needed. + needed info about Flash structure
Terastation Pro v1
TODO: add specific Info if additional hardware mods are needed. + needed info about Flash structure
Mipsel-based boxes
TODO: Add info about the JTAG cable that works on the + needed info about Flash structure
LS2
Arm-based boxes
Tampakuro/kuroguy discovered the layout of the JTAG Port on LS Pro v1 and an early KuroPro by tracing the wiring. The account of his work and early efforts is here : JTAG for the LS Pro and LS Live. He found that the v1 had a non-standard pinout. The v2 LS Live has a standard ARM 20 pin layout. mdfirefighter and others discovered that Dominic Rath's OpenOCD software was the key to opening the LS Pro to JTAG - this is detailed in the same thread linked to above.
LS Pro/LS Live (arm9)
Flash structure
For the LSProV2, here is the output of flinfo while in u-boot:
Marvell>> flinfo Bank # 1: SST SST39VF020 (2 Mbit) Size: 256 kB,Bus Width: 1, device Width: 1. Flash base: 0xfffc0000,Number of Sectors: 64 Type: REGULAR. Sector Start Addresses: 00000000 (RO) 00001000 (RO) 00002000 (RO) 00003000 (RO) 00004000 (RO) 00005000 (RO) 00006000 (RO) 00007000 (RO) 00008000 (RO) 00009000 (RO) 0000a000 (RO) 0000b000 (RO) 0000c000 (RO) 0000d000 (RO) 0000e000 (RO) 0000f000 (RO) 00010000 (RO) 00011000 (RO) 00012000 (RO) 00013000 (RO) 00014000 (RO) 00015000 (RO) 00016000 (RO) 00017000 (RO) 00018000 (RO) 00019000 (RO) 0001a000 (RO) 0001b000 (RO) 0001c000 (RO) 0001d000 (RO) 0001e000 (RO) 0001f000 (RO) 00020000 (RO) 00021000 (RO) 00022000 (RO) 00023000 (RO) 00024000 (RO) 00025000 (RO) 00026000 (RO) 00027000 (RO) 00028000 (RO) 00029000 (RO) 0002a000 (RO) 0002b000 (RO) 0002c000 (RO) 0002d000 (RO) 0002e000 (RO) 0002f000 (RO) 00030000 (RO) 00031000 (RO) 00032000 (RO) 00033000 (RO) 00034000 (RO) 00035000 (RO) 00036000 (RO) 00037000 (RO) 00038000 (RO) 00039000 (RO) 0003a000 (RO) 0003b000 (RO) 0003c000 (RO) 0003d000 (RO) 0003e000 (RO) 0003f000
Background and Equipment
INCOMPLETE - Do Not Attempt At This Time
- These directions have been tested and checked on a LSProV2, with a Ubuntu 7.10 box (x86) and an Olimex ARM-USB-TINY jtag/usb programmer/debugger. Parallel port debuggers are certainly an option, but will probably yield lower speeds.
Setting Up OpenOCD
- Compiling
See
- Configuring and Starting OpenOCD
- Available Commands in OpenOCD
While in OpenOCD, entering the command help will yield a list of available commands and summary of help.
> help help display this help sleep sleep for <n> milliseconds version show OpenOCD version shutdown shut the server down exit exit telnet session log_output redirect logging to <file> (default: stderr) debug_level adjust debug level <0-3> jtag_speed set jtag speed (if supported) <speed> scan_chain print current scan chain configuration endstate finish JTAG operations in <tap_state> jtag_reset toggle reset lines <trst> <srst> runtest move to Run-Test/Idle, and execute <num_cycles> statemove move to current endstate or [tap_state] irscan execute IR scan <device> <instr> [dev2] [instr2] ... drscan execute DR scan <device> [ dev2 ] [var2] ... verify_ircapture verify value captured during Capture-IR <enable|disable> var allocate, display or delete variable <name> [num_fields|"del"] [size1] ... field display/modify variable field <field> [value|"flip"] script execute commands from <file> xsvf run xsvf <file> targets no help available flash no help available banks - list configured flash banks info - print info about flash bank <num> probe - identify flash bank <num> erase_check - check erase state of sectors in flash bank <num> protect_check - check protection state of sectors in flash bank <num> erase - erase sectors at <bank> <first> <last> write - write binary <bank> <file> <offset> protect - set protection of sectors at <bank> <first> <last> <on|off> nand no help available pld programmable logic device commands arm7_9 arm7/9 specific commands write_xpsr - write program status register <value> <not cpsr|spsr> write_xpsr_im8 - write program status register <8bit immediate> <rotate> <not cpsr|spsr> write_core_reg - write core register <num> <mode> <value> sw_bkpts - support for software breakpoints <enable|disable> force_hw_bkpts - use hardware breakpoints for all breakpoints (disables sw breakpoint support) <enable|disable> dbgrq - use EmbeddedICE dbgrq instead of breakpoint for target halt requests <enable|disable> fast_writes - (deprecated, see: arm7_9 fast_memory_access) fast_memory_access - use fast memory accesses instead of slower but potentially unsafe slow accesses <enable|disable> dcc_downloads - use DCC downloads for larger memory writes <enable|disable> etb_dump - dump current ETB content armv4_5 armv4/5 specific commands reg - display ARM core registers core_state - display/change ARM core state <arm|thumb> disassemble - disassemble instructions <address> <count> ["thumb"] arm9tdmi arm9tdmi specific commands vector_catch - catch arm920t vectors ["all"|"none"|"<vec1 vec2 ...>"] arm926ejs arm926ejs specific commands cp15 - display/modify cp15 register <opcode_1> <opcode_2> <CRn> <CRm> [value] cache_info - display information about target caches virt2phys - translate va to pa <va> mdw_phys - display memory words <physical addr> [count] mdh_phys - display memory half-words <physical addr> [count] mdb_phys - display memory bytes <physical addr> [count] mww_phys - write memory word <physical addr> <value> mwh_phys - write memory half-word <physical addr> <value> mwb_phys - write memory byte <physical addr> <value> cfi no help available reg no help available poll poll target state wait_halt wait for target halt [time (s)] halt halt target resume resume target [addr] step step one instruction reset reset target [run|halt|init|run_and_halt|run_and_init] soft_reset_halt halt the target and do a soft reset mdw display memory words <addr> [count] mdh display memory half-words <addr> [count] mdb display memory bytes <addr> [count] mww write memory word <addr> <value> mwh write memory half-word <addr> <value> mwb write memory byte <addr> <value> bp set breakpoint <address> <length> [hw] rbp remove breakpoint <adress> wp set watchpoint <address> <length> <r/w/a> [value] [mask] rwp remove watchpoint <adress> load_image load_image <file> <address> ["bin"|"ihex"] dump_image dump_image <file> <address> <size> load_binary [DEPRECATED] load_binary <file> <address> dump_binary [DEPRECATED] dump_binary <file> <address> <size>
Starting OpenOCD and Connecting with Telnet
You will need to do both of the following as root:
- In a terminal window, cd to your OpenOCD config file and start it. From this window you will see only diagnostic information, mainly. Change directory to the docs/configs in the openocd directory. Then start openocd, directing it to use the config file that you have set up previously.
root@bitbaker-i686:/home/davygravy/Desktop/configs# openocd -f lsp_wig.cfg Info: openocd.c:86 main(): Open On-Chip Debugger (2007-04-26 16:40 CEST) Error: embeddedice.c:190 embeddedice_build_reg_cache(): unknown EmbeddedICE version (comms ctrl: 0x00000018)
The error seems commonplace to most of us that have used it. Until we know otherwise, most of us are assuming it is not a huge problem. OpenOCD is now running.
- In a second terminal window, start telnet pointed to loopback, port 4444. This window is where you will control the communication and commands to your device via the jtag interface. You will have to halt your processor, verify the flash banks, and probe them (so that they are recognized properly).
root@bitbaker-i686:/usr/src# telnet localhost 4444 Trying 127.0.0.1... Connected to localhost. Escape character is '^]'. Open On-Chip Debugger > halt requesting target halt... > Target 0 halted target halted in ARM state due to debug request, current mode: Abort cpsr: 0x600000d7 pc: 0x00000028 MMU: disabled, D-Cache: disabled, I-Cache: enabled > flash banks #0: cfi at 0xfffc0000, size 0x00040000, buswidth 1, chipwidth 1 > flash probe 0 flash 'cfi' found at 0xfffc0000
Once this is done, you have verified that you have proper access to the flash. Now erase it, check your erase and then write the u-boot.bin file to flash. This may take anywhere from about an hour up to 5 or 6 hours. Do not interrupt the process.
> flash erase 0 0 63 erased sectors 0 through 63 on flash bank 0 in 4s 484466us > flash erase_check 0 successfully checked erase state > flash write 0 /usr/src/openocd-package/doc/configs/lspstock052207.bin 0xfffc0000 wrote file /usr/src/openocd-package/doc/configs/lspstock052207.bin to flash bank 0 at offset 0xfffc0000 in 12107s 811284us >
Verifying Flash and Flashing
Notes and Special Situations
At least a handful of us have flashed once or twice, and then been able to proceed with a third flash. Presumably, the processor was in a state that allowed us to do the first flash(es) but for some unknown reason comes to be in some less manageable state.
Terastation Pro v2/Terastation Live (arm9)
Similar to the other arm9-based boxes from buffalo these 2 only have uboot in flash. everything else is read and executed from harddisc.
Software
See JTAG Software
PPC-based-boxes
How to use the JTAG-Tools
TODO: we need to link + describe either how to compile the tools and how to use the precompiled tools from the download-section
LS2 (mipsel-based)
How to use HairyDairyMaids debrick
TODO: adding info about how to use it
TIPS
Flashing the bootloader only
Updating via JTAG is very slow. This is not really surprising as the JTAG protocol is a bit-level serial protocol. Writing the firmimg.bin file can easily take 24 hours or longer.
TODO: because we can flash the firmimg.bin much faster from UBoot
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