/tjtag-arduino

Use the arduino as a JTAG adaptor with Tjtag

Primary LanguageC

Source code and documentation for a version of tjtag that connects to a router's JTAG port through an Arduino board.

Original source code was posted here:

http://www.dd-wrt.com/phpBB2/viewtopic.php?p=435578&sid=0c7c7b114dc7239be2620514cecbe2d8

Use case: Erasing nvram on Linksys WAP54G with dd-wrt running

I had fucked up the dd-wrt installation, forgetting to set nvram version to three, that caused the reset button not to work. That combined to bad configuration on WAP port i had the box unreachable. The only way to reset the box to factory defaults was to use jtag connection.

  • Arduino: duemilanove/atmega 328 - worked out of the box, except that i had to retry the launch few times before "reseting arduino" went ok.
  • OS: Ubunutu 14.04.3 / 3.15.0-031500rc2
  • Target: WAP54G 3.1, running dd-wrt v24 - image on dd-wrt wiki page is from older version, same pins worked though.
  • Command: ./tjtag -erase:nvram /wiggler /noreset
  • Notes: It did not work without /wiggle /noreset. Chip identification worked fine.

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