[coreboot] Serengeti VGA
Marc Jones
Marc.Jones at amd.com
Mon Oct 20 22:26:03 CEST 2008
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.
Marc
--
Marc Jones
Senior Firmware Engineer
(970) 226-9684 Office
mailto:Marc.Jones at amd.com
http://www.amd.com/embeddedprocessors
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