[coreboot] SeaBIOS on DBE63 not functional

[Kevin O'Connor]

On Thu, Jan 29, 2009 at 12:33:04PM +0200, Mart Raudsepp wrote:
> All the other bootloaders used as payloads work just fine without a VGA
> BIOS - FILO, etherboot, etc. Under not assuming boot loaders will just
> "work" without a VGA BIOS, do you mean the boot loaders found in MBRs?

Yes.

> > There has been discussion of porting the open source vga bios to
> > geode.
> I've seen some vague mentions of it, but nothing concrete besides plans
> without details, and nothing even close to actual code :(
> I hope I've just missed something. While on that topic, some more
> detailed planning might be useful - is there something this is good to
> be based on? is there a good idea how it should get hooked it? etc

There was a thread on this starting at:

http://www.coreboot.org/pipermail/coreboot/2008-October/039657.html

There exists an open source vga bios today (
http://www.nongnu.org/vgabios/ ).  So, in theory one could port it to
the geode.

I'd recommend porting the current open source vga bios to gcc (much
like SeaBIOS is a port of bochs bios to gcc).  Then, one would need to
either change all the ioport calls in the bios to use the geode
equivalents, or implement some vsa/smm wrapper that caught the vga
ioport accesses and emulated their functionality.

> > You'll need the vga bios for xp.  One can verify this with qemu -
> > without the vga bios it wont start.
> 
> Most unfortunate. What is it wanting from it besides just drawing stuff.
> Is it expecting some kind of replies or return values back unlike some
> other things?

I don't know.  A qemu test shows grub wants a vga bios too.  Lilo
might still work.

-Kevin