TUMPA, Windows 8.1, zJTAG v1.8, and e4200

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TUMPA, Windows 8.1, zJTAG v1.8, and e4200

jrscs

I have Windows 8.1 working with TUMPA and zJTAG v1.8. I’m trying to JTAG an e4200 that is in a continuous boot loop. Serial did not allow the boot process to be stopped so NVRAM could be erased.
zJTAG is able to detect the Broadcom CPU chip, but is not able to detect the FLASH chip. In looking at the FLASH chip options the e4200 FLASH chip is not listed. The e4200 shows a Winbond 25Q128BVFG chip, which is a 16MB chip.
So, here is my question. Since the FLASH chip is not listed, is it possible to manually enter zJTAG switch commands so it can be located and then have the NVRAM erased? If so, does anyone know the switch settings?
Thanks

joecop67

I'm in the same boat. No answer yet. Seems like all the various jtag programs are dead.

jrscs

I was able to de-brick the e4200 using a Universal JTAG Adapter V2 with tjtag 3.0.2.1-win32 software. Turned out the trick to my brick was timing. Starting the router and then starting the software right away was the trick. But, it took a number of tries to get the timing right.

[deleted]

Latest development build of OpenOCD supports TUMPA and TUMPA-Lite, and it can flash E4200.
Please see; http://www.tiaowiki.com/forums/index.php/topic,4121.msg5857.html#msg5857
You can get help for OpenOCD on FreeNode IRC server, #openocd channel. You can Connect now using Freenode webchat, no IRC client needed.
There is also Free Online Documentation available on http://openocd.sourceforge.net/documentation/

joecop67

I just realized he said he was using tumpa. I have the parallel adapter.

[deleted]

Unfortunately TJTAG (Tornado mod of JTAG Debrick Utility) does not support TUMPA/TUMPA-Lite.
I am working on zJTAG development (including new router/chip support) and expecting to release new beta in the next weeks.
BTW, OpenOCD includes an easy-to-use script to facilitate mass-market devices recovery with JTAG.
For quickstart instructions run:

openocd -f tools/firmware-recovery.tcl -c firmware_help