[coreboot] SeaBIOS debug output

[Myles Watson]

On Fri, Jul 11, 2008 at 12:51 PM, Kevin O'Connor <kevin at koconnor.net> wrote:
> On Fri, Jul 11, 2008 at 07:58:35PM +0200, Carl-Daniel Hailfinger wrote:
>> Can seabios somehow complement x86emu as a way to let certain
>> problematic VBIOS images run?
>
> If you mean run seabios under x86emu - I'm not sure.  Seabios
> currently does its initialization in 32bit mode which x86emu may not
> like.
>
> If you mean using seabios to implement the option rom scan - then yes,
> I think this is what Stefan suggested and Zhang Rui is working on.  If
> I understand correctly, they want to load the seabios blob into ram,
> have seabios do its init, run the option roms, and then jump back to
> coreboot for the rest of the boot.  Presumably, coreboot would also
> use seabios to boot the machine if the user wanted that.
>
> The thing to be careful of here is making sure coreboot and seabios
> don't stomp on each other.  This may not be such a big deal - seabios
> doesn't currently write to any ram above 1MiB - if coreboot didn't
> write to any ram below 1MiB after launching seabios then maybe it
> would work.

I for one don't understand what needs to be done in coreboot after the
option ROM scans.  It seems like it would help us discuss the possible
solutions if we could enumerate that.

I don't think the Coreboot->SeaBIOS->Coreboot->Payload route means
that SeaBIOS has to return to Coreboot.  It seems like Coreboot can
load whatever should come after SeaBIOS into RAM and have SeaBIOS jump
there.  Maybe to Peter's alternate boot interface.  If it replaces the
emulator from Coreboot, it no longer qualifies as a "mandatory
payload", but I don't think we need to fork the source.  I like the
idea of having a broad user base testing as much common code as
possible.

>On Fri, Jul 11, 2008 at 02:51:12PM -0400, Kevin O'Connor wrote:
>> If you mean using seabios to implement the option rom scan
>..
>> maybe it would work.
>
>Yes, I think it would work very well.

SeaBIOS has no way of knowing where onboard ROMs are stored.  That
seems like a problem that needs to be solved.

Thanks,
Myles