[coreboot] SeaBIOS debug output

Jordan Crouse jordan.crouse at amd.com
Fri Jul 11 19:32:06 CEST 2008

On 11/07/08 13:10 -0400, Kevin O'Connor wrote:
> Hi,
> On Fri, Jul 11, 2008 at 10:04:27AM -0600, Jordan Crouse wrote:
> > Hmm - I'm starting to see Stefan's concerns.  Many of our payloads don't
> > need SeaBIOS functionality, but most need (or at least will use) option
> > ROMs (especially our good friend VGA).  If there is going to be some
> > conflict between coreboot and SeaBIOS in this area, then really, the only
> > option is to put SeaBIOS into coreboot.
> I'm unconvinced that integrating SeaBIOS and coreboot at a source code
> level is a good plan.  SeaBIOS is also applicable to qemu and kvm - I
> think there is a big advantage to having seabios used as the bios for
> emulators - that community of users and developers is currently much
> larger than coreboot.

So clearly we have much less in common then we previously thought.

> I can see a setup where coreboot initializes the machine and hands
> control over to SeaBIOS (as a payload) and then SeaBIOS boots the OS
> (including enablement of vga).  It may be too simplisitc, but I see
> benefit to keeping coreboot focused on hardware initialization, while
> the payload focuses on OS booting.

I would agree, except that where exactly optionROMs live is debatable.
Is it hardware initialization?  Is it OS support?  A little bit of 
both?  The problem is that the vast majority of coreboot setups in
the world today do not need SeaBIOS.  but all except for the Geode
require optionROMs.

> >I don't really favor forcing
> > folks to start using the payload chooser to load SeaBIOS in order to
> > grok VGA ROMs.  That seems like it is asking too much of the 
> > end developer.
> I agree.  However, if seabios was the payload and it pulled the
> chooser out of flash (or the chooser was linked into seabios), then
> maybe we could sidestep this issue.  That is, instead of going
> coreboot->chooser->seabios->chooser->OS we could go
> coreboot->seabios->chooser->OS.

I'm not sure if that works well for anybody, especially you.  The
chooser would have zero value for your other customers, and I don't
think that SeaBIOS wants to acquire the intrinsic LAR knowledge and
configuration that the chooser has to deal with today.  SeaBIOS
is functional, the chooser is silly, non essential eyecandy.  The
two do not fit well together.

I am going on record as saying that I think it is a mistake to go
down the path of making SeaBIOS a mandatory but separate payload
for coreboot.  I think there has to be a better way.


Jordan Crouse
Systems Software Development Engineer 
Advanced Micro Devices, Inc.

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