On Thu, Jun 11, 2009 at 22:51, Carl-Daniel Hailfingerc-d.hailfinger.devel.2006@gmx.net wrote:
Yes, this would work with a bit of soldering. I looked through the data sheets and came up with a way to do this: Desolder the ID2 pin of the old chip from the board and connect it to VDD (3.3V). Solder the new chip (with the correct BIOS image) on top of the old chip, but connect ID2 of that chip to ground. Once that is done, the machine should boot normally. After booting, you'll have to modify flashrom to target the old chip or you'll simply overwrite the new chip which would be rather undesiarable.
I've just done some reading, that should do the trick. Except according to the datasheet you should use ID3 for this not ID2, essentially the ID pins control where in the 8M of space the contents of the chip gets mapped, by using ID3 you can flip your 4M ROM between the top and the bottom of the address range, as I say I've not looked too deeply into LPC but my reading of the datasheet suggests that if you use ID2 you will end up with half of your two ROMs overlapping.