[U-Boot] [coreboot] U-Boot-x86 / coreboot Integration

[Kevin O'Connor]

On Wed, May 11, 2011 at 01:12:16PM +1000, Graeme Russ wrote:
> >> > for two or three graphics chipsets. SeaBIOS can initialize any VGA
> >> > option ROM, but then you need SeaBIOS in the loop.
> >> > Option ROMs are ageold technology and stupid, but they are still
> >> > firmly entrenched in PC hardware. A BIOS was always there so everyone
> >> > assumes it will always stay there, not very many question if
> >> > something better could be done.
> >>
> >> Would be interesting to investigate implementing a stub in U-Boot to
> >> initialise and use VGA option ROMs
> >
> > VGA option ROMs call BIOS functions.  So, one needs a BIOS
> > implementation (eg, SeaBIOS) or an emulator for them (eg, in
> > coreboot).
> 
> What does Linux do? i.e. if you boot Linux from coreboot, how does it
> output to the VGA console? I know it uses BIOS early on (before switching
> to protected mode) but what does it do after entering protected mode?

In general, one enables the coreboot VGA option ROM emulation when
booting Linux directly from coreboot.

-Kevin