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.
Andrew
Andrew,
Would happen to know which linux driver handles this interrupt?
Also, do you know where is this "correct handshake" described? It seems that once bit 1 is set it can only be cleared by the reset. ---- rich
On Sat, Feb 9, 2013 at 5:34 PM, Andrew Goodbody ajg4tadpole@gmail.comwrote:
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.
Andrew
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Andrew Goodbody -
Rich Futyma