[SeaBIOS] GeodeVGA is not initialized during SeaBIOS execution

[Andrey Korolyov]

On Mon, Jul 11, 2016 at 3:09 AM, Kevin O'Connor <kevin at koconnor.net> wrote:
> On Mon, Jul 11, 2016 at 02:23:12AM +0300, Andrey Korolyov wrote:
>> Hi,
>>
>> as per Kevin`s suggestion, I am posting initialization log (mixed one)
>> from initialization of the GeodeLX board. As it could be clearly seen
>> from the log, VGA option ROM was never called and executed during the
>> initialization sequence, therefore issue with a lack of video output
>> during SeaBIOS stage on this board looks somehow logical. [1] suggests
>> that the problem existed long before, as most users of these boards
>> are Alix owners who do not care about existence of the video output :)
>
> Best guess is this check:
>
>     u16 cmd = pci_config_readw(pci->bdf, PCI_COMMAND);
>     if (!(cmd & PCI_COMMAND_IO && cmd & PCI_COMMAND_MEMORY))
>         return 0;
>
> in optionroms.c:is_pci_vga() is being triggered.  You could see if
> coreboot is not enabling these PCI flags, temporarily disable the
> check in seabios, or use "vgaroms/seavgabios.rom" instead of
> "pci1022,2081.rom" for the seavgabios rom.
>
> -Kevin

Awesome suggestion, turns out that the PCI_COMMAND_IO is not set.
Removing the check entirely would lead to an incomplete PCI
initialization but placing VGA ROM to vgaroms/seavgabios.rom could do
the trick.