You mean, autoexec.bin? How did you manage to lock up the camera without enabling the boot flag first?!
Anyway, here's the portable ROM dumper: DUMP1300.FIR
If successful, please send me the ROM by PM.
The info looks fairly similar to digic 4; the two 32MB ROMs are a bit unusual. RAM seems to be 256M.
Your first task is to run your ROM under QEMU (same for anyone else interested). Without seeing the firmware, I expect:
- loading autoexec from SD card should work with little or no tweaking (it may lock up at some GPIO registers, easy to fix)
- the portable display test should also run with minimal effort
- if you run it under GDB, you should also see a few tasks starting
- if you are lucky, you might even see Canon GUI (but don't get your hopes too high on this one).