On Wed, May 11, 2011 at 09:44:00AM +1000, Graeme Russ wrote:
On Wed, May 11, 2011 at 2:08 AM, Peter Stuge peter@stuge.se wrote:
Graeme Russ wrote:
- Do we care about legacy BIOS support (SeaBIOS) for now (I think not)?
IMO it is not relevant to the integration of coreboot and U-Boot. If a BIOS is needed by U-Boot itself or whatever it loads, then SeaBIOS must be used as payload for coreboot, and SeaBIOS will then start U-Boot after setting up the BIOS environment.
Or U-Boot could load a SeaBIOS image and initialise it if needed. So in a U-Boot script:
- If the target OS is GNU/Linux the load the Linux kernel image and go
- If the target OS is Windows (or any other OS which needs a BIOS) then U-Boot first loads a SeaBIOS image and then loads the image for the target OS (this may even be a 'GRUB' image for example)
That's possible to do, but would likely require some changes to SeaBIOS.
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).
-Kevin