The VGA Bios has to be extracted like Jun said:
# dd if=/dev/mem of=video.bios.bin.4 bs=1 count=65536 skip=786432 786432 is 0xc0000, and 790528 which Nich told is 0xc1000.
I still can not run X yet. You do same stuff after booted with Linux BIOS and check if you can get same BIOS image as you burned to your flash chip. Anton Borisov noticed same thing, but in my test, the BIOS image is different!. I am guessing this could be the cause. Try it.
--- Okajima, Jun. Tokyo, Japan.