[flashrom] Fwd: BIOS Write Enable bit problem.

Andrew Goodbody ajg4tadpole at gmail.com
Sun Feb 10 01:34:37 CET 2013

On 08/02/13 23:47, Rich Futyma wrote:
> Does anyone know why bit 0 in the BIOS Control register cannot be set using
> Intel® X79 Express Chipset. This is what I get when running:
> flashrom -r /tmp/bios.rom -p internal or  flashrom -w xx.rom -p internal
> *Warning: Setting Bios Control at 0xdc from 0x2a to 0x0b on X79 failed.*
> *New value is 0x2a.*

You can see that bit 1 is already set. This will generate an SMI when 
you attempt to set bit 0. There will be SMM code that will reset bit 0 
if you have not performed the correct handshake beforehand. This is a 
protection mechanism to prevent unauthorised modification of the BIOS.


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