Re: [coreboot] [Qemu-devel] Release plan for 0.12.0

[Stefan Reinauer <stepan@coresystems.de>]

Anthony Liguori wrote:
> Patrick Georgi wrote:
>> With coreboot, seabios and Duet, it should be reasonably simple to
>> provide a single BIOS image that selects (based on nvram - ie.
>> configuration) which interface to provide: PCBIOS or UEFI.
>>   
>
> That isn't terribly useful for QEMU because it implies that QEMU needs
> to make the decision about which one to use.  If QEMU was capable of
> making that decision without user intervention, then we could just
> select to load PCBIOS or UEFI.
Are you guys sure you want to go down that road rather than using an
UEFI with a CSM? There may be cases when you really want to boot legacy
even though your client can do UEFI.

> I don't know enough about EFI, but my concern is that down the road,
> hardware devices will start to exist that require EFI because they
> implement EFI modules and not legacy option ROMs.  In order to support
> PCI passthrough of such devices, we will need to provide an EFI
> capable firmware.
>
> It's really just a matter of how long before this becomes a problem
> for us.
This was attempted for Open Firmware and never happened during its life
time. I doubt there is any incentive for vendors to ship devices without
legacy option roms, especially since there is no advantage in doing so.

Stefan