Proxmark3 community

thefkboss

Contributor

Registered: 2008-10-26

Posts: 198

i need to used a jtag device but what is the correct one??

hi
i tryed to upload the osimage but my proxmark crashed so know i need to used a jtag device.
i´ve been looking and i found diferents models.
do you know one that work fine??? could you give me the link??
i have bought this one:

http://cgi.ebay.es/JTAG-Programmer-JTAG … 414a04e11c

this will work???
thanks

Last edited by thefkboss (2009-11-01 14:12:06)

henryk

Contributor

Registered: 2009-07-27

Posts: 99

Re: i need to used a jtag device but what is the correct one??

Failing an osimage upload will not brick your proxmark, you can still flash it using the bootloader. Simply press the button before connecting the proxmark to power and keep it pressed during the entire flash process. The red and orange buttons should light continuously to indicate that the device is in bootloader mode and you can use the flash tool to program a new osimage.

(As for JTAG programmers: I particularly like the JTAGkey tiny.)

thefkboss

Contributor

Registered: 2008-10-26

Posts: 198

Re: i need to used a jtag device but what is the correct one??

thanks
now works perfect.
but i also like to learm so i going to try with my jtag when it arrive.
i have some doubts:
when you use the jtag you upload the current bootrom and after that you upload by usb the os and fpga files
or you have to upload fisrt 2008.09.17-armpgm-ebuller-proxmark3-image.S19 and after that the bootrom and os and fpga files by usb???
thanks

henryk

Contributor

Registered: 2009-07-27

Posts: 99

Re: i need to used a jtag device but what is the correct one??

No. Do not use ancient, i dare say: prehistoric, bootroms like that one. It's perfectly fine to use all the current s19 files for FPGA programming, see http://www.proxmark.org/forum/topic/294 … h-openocd/ for hints on how to work with openocd. (Ignore some of the obsolete stuff in that post: merge-srec.pl is fixed and gone, and bootrom-merged.s19 now is simply called bootrom.s19)

The main gotcha is that for historic reasons the .s19 files are located at the wrong offset in memory: they are relative to 0x0, while the flash resides at 0x100000. You need to take that into account when programming (that's what the explicit offset in the flash write_image command does). The translation happens in the conversion from elf to s19, so the elf files don't need such special treatment. I think openocd can flash elf directly (haven't tried recently).

thefkboss

Contributor

Registered: 2008-10-26

Posts: 198

Re: i need to used a jtag device but what is the correct one??

ok
thanks