[SeaBIOS] [PATCH] Support more than one vga card

Glauber Costa glommer at redhat.com
Wed May 4 00:07:14 CEST 2011

On Wed, 2011-05-04 at 00:02 +0200, Sebastian Herbszt wrote:
> Anthony Liguori wrote:
> > On 05/03/2011 03:23 PM, Sebastian Herbszt wrote:
> >> Glauber Costa wrote:
> >>> It is theorectically possible for a system to have more than
> >>> one pci vga card. In particular, I am interested in the use of SGAbios
> >>> as a pci device, alongside of a normal vga bios in QEMU.
> >>
> >> Can't SGAbios be loaded as an option rom without this change?
> > 
> > But then you're loading it as a legacy ROM which is fairly ugly and 
> > requires additional SeaBIOS hackery.
> Why is this ugly and which additional hackery does it need?
> SGAbios is a legacy ROM; the PNP header is disabled and there is no PCIR.

It is, but does not need to be (I've also patched sgabios to include a
PCIR). Since it is a device, it is nice to have it plugged it to a bus.
If for nothing else, for discovering capabilities - A guest using
sgabios this way is now aware that it has a double-head system.

Also, let us not focus only in the specifics: Having two pci vga cards
is a real possibility, there's even a use case for that, as anthony

> Sebastian

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