[coreboot] Serengeti VGA

Marc Jones Marc.Jones at amd.com
Mon Oct 20 22:32:41 CEST 2008

Marc Jones wrote:
> Myles Watson wrote:
>> On Mon, Oct 20, 2008 at 1:48 PM, Marc Jones <Marc.Jones at amd.com 
>> <mailto:Marc.Jones at amd.com>> wrote:
>>     Myles Watson wrote:
>>         I've been trying to make the configuration spaces match between
>>         v2 and v3.
>>         The biggest difference left is the disabled/hidden devices which
>>         are not
>>         hidden in v3.
>>         Any chance that's causing the problem?
>>         I've also been trying to figure out where the legacy IO space
>>         (e.g. 0x3d4)
>>         gets routed to the card.  Does this happen automatically because
>>         the VGA bit
>>         is set in the bridge?
>>     Yes, The vga bit on the subtractive bridge routes the graphics io.
>>     How did you work around the vm86 problem? Did the graphics command
>>     register get re-enabled?
>> I made the interrupts self contained, with no output.  The VGA ROM 
>> initialization returns, but there is no output to the screen.  At 
>> least the screen turns black on an int10 now, though.
>> The only differences between the PCI configuration registers now is 
>> that v3 has a little larger space for VGA and SERR is set.
> Ok, That should be fine. Black usually means all FF in the vga memory. 
> Check A000-BFFFF are getting to the controller. VGA enable in the bridge 
> control register (3e) and VGA pallet snoop in the command register (04) 
> should be set in the bridge.

Sorry, I had that backwards FF is blinking white, 00 is black.


Marc Jones
Senior Firmware Engineer
(970) 226-9684 Office
mailto:Marc.Jones at amd.com

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