Jordan Justen wrote: > On Sat, Oct 3, 2009 at 15:02, Stefan Reinauer <[email protected]> wrote: > >> Jordan Justen wrote: >> >>> On Sat, Oct 3, 2009 at 10:30, Peter Stuge <[email protected]> wrote: >>> >>> >>>> Jordan Justen wrote: >>>> >>>> >>>>> Anyway, it sounds like a useful project might be to develop a UEFI >>>>> coreboot payload based on the tianocore.org code. >>>>> >>>>> >>>> I believe it might have been done already. >>>> >>>> http://www.coreboot.org/File:Tianocoreboot.png >>>> >>>> >>> That screenshot mentions DUET which is the tianocore.org UEFI emulator >>> that boots on top of a legacy BIOS. But, it's unclear if it was just >>> DUET, or something based modified specifically for coreboot based on >>> DUET. >>> >>> I will not dispute that DUET might be a potential solution to achieve >>> UEFI compatibility for QEMU. (I'm not sure, but I think DUET may not >>> be able to boot UEFI OS's at this time.) However, we thought a >>> project such as OVMF was a more direct approach to achieve UEFI >>> compatibility for QEMU. >>> >>> >> We have DUET running as a coreboot payload with a small coreboot >> specific PE payload loader. >> > > Meaning you bring up a legacy BIOS compatible interface before > starting DUET? No. > DUET depends on a legacy BIOS. It did not for us, except for the loader which was replaced. We might have been lucky though...
> My point is that a tianocore.org based coreboot payload ought be able to do > away with > this legacy BIOS dependency. > Absolutely agreed. At some point it might make sense to have a coreboot specific target next to OVMF and DUET, some corebootPkg with specific adaptions and the loader integrated. The requirements for a coreboot target are very similar to those of OVMF and/or Duet, I guess. No hardware specific code is required, but in addition to what OVMF provides, we feature an in-flash filesystem and we export a coreboot table which contains memory information, cmos layout among other things... What are the chances to get something like this integrated upstream TianoCore.org? >> Can you explain what you think would be more direct about OVMF than >> about DUET? As far as I understand it's another build target of EDK2 but >> besides that shares exactly the same design and even 99% of the code. >> > > DUET expects that you boot a legacy BIOS, and then you load DUET off > the disk. It does expect a few tables, but does not seem to make any 16bit calls once loaded. > Once DUET is loaded, there is a (mostly) UEFI compatible > environment. > I'm curious on the "mostly" here... what's missing? We certainly want to make sure what we do is fully UEFI compatible. > Both DUET and OVMF have some slight issues with providing a fully > compatible UEFI variable interface. Is that about saving settings in an NVRAM/flash memory? Stefan -- coreboot mailing list: [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
