[LEDE-DEV] Archer c7 corrupted firmware bootloop - tftp aborting - serial not working

[Russell Senior]

>>>>> "QWeRKUS" == QWeRKUS qwErkus <qwerkus at gmail.com> writes:

QWeRKUS> Thank you for your replies. Turns out the problem was the
QWeRKUS> ground connection, and serial nowworks with
QWeRKUS> pl2303. Unfortunately I mixed up 2 addresses when flashing the
QWeRKUS> new firmware, and erased from 0x9f000000 on instead of
QWeRKUS> 0x9f020000. As a result, my boot loader is corrupt. Now I'm
QWeRKUS> trying some last resort salvage over JTAG, using an rpi with
QWeRKUS> openocd as JTAG dongle. Assuming I manage to compile openocd
QWeRKUS> with ath79 support (which currently fails), can I use the
QWeRKUS> u-boot from pepe2k to restore my uboot ? I yes, how does it
QWeRKUS> work: just copying the bin to flash from 0x9f000000 onwards ?

Another approach is to write the flash with an external programmer.  You
might need to desolder the flash chip, if you can't figure out how to
hold the CPU in reset.  It looks like the c7 has a regular SPI flash
chip.  It is probably just an 8-pin part, and not too hard to desolder,
if you need to.  Solder wick is handy for cleaning up the pads after you
remove it.  

I have recently used a bus pirate or a teensy 3.1 with the flashrom
program to read/write spi flash.  Likely to be Way easier that trying to
figure out JTAG.  Make *very* sure you have a (or several) complete
backup of the flash part before writing over it.


-- 
Russell Senior, President
russell at personaltelco.net