VGA Problem about 440bx chipset

Richard Smith rsmith at
Tue Sep 7 18:11:00 CEST 2004

ron minnich wrote:

>>option SHADOW_VGA_BIOS=1
>>option SHADOW_VGA_BIOS_DEST=0xC0000
> we'll put this on the list, though not quite this way (unless you want it 
> in V1)

Well until myself or some other industrious soul ports the 440bx stuff 
to V2 its not much use to me unless its V1.

It dosen't really matter to me how its implemented in V1. If you have 
what you think is the "right" way then I'm game.  And if someone will 
guide me through what needs to be done in the PCI allocation stuff I'll 
give it a whirl but at first blush that PCI allocation stuff appears 
fairly complex.

I guess the part I need help on would be the methodology of the ROM 
expansion address assignment.

The actual copy seems pretty trivial.

  - Scan for the id of the vga device.
  - Get the rom address and enable the decode.
  - set the shadowing.
  - do the copy.
  - disable writes to the shadow.
  - disable the ROM decode.


More information about the coreboot mailing list