Hi All. I have been doing some work on reverse engineering the jtag/ocd interface on the ppc440epx (which is a closed protocol). Turns out I've had a bit of luck. It is now possible to 'debrick' a ROACH board, ie load up a bootloader, without any proprietary tools or programmers.
The programmer I have used is an Amontec JTAGKey Tiny (which has an FTDI ft2232 chip on it). The JTAG operation are performance using urjtag, a nice GPL'ed tool which supports a number of jtag programmers. I have put all the details up on: http://casper.berkeley.edu/wiki/ROACH_Debricking The solution, as it sits, is rather incomplete, ugly, and less than ideal. However, it does seem to work. Here is a link describing the secret COP interface. http://www.mail-archive.com/[email protected]/msg30394.html I am pretty excited about this! Hopefully IBM and Freescale don't hunt me down... Cheers, David -- David George Karoo Array Telescope Tel: +27 11 442-2434 Email: [email protected]
