[coreboot] ADLO for buildrom

[Myles Watson]

> OK, fine. Would it hurt to use the aligned version for non-kexec too?
> Any drawbacks?

The only drawback is size.  It adds 3K of zeroes if you don't compress it.

> 
> OK, then it probably doesn't matter much. If and how can the loader be
> integrated upstream? That's probably the best place to store it, correct?

I don't think the loader should be integrated upstream.  If we can get Bochs
and QEMU to adopt the gcc port of the BIOS, it will have more testers and be
more stable.  They don't want the loader.

> > > > +-; code it is loaded into memory at 0x7C00
> > > > ++; code it is loaded into memory at 0x7000
> > >
> > > Why? Please explain. Is this board-specific or payload-specific?
> > > Can it be a variable, selectable in a config file later?
> > > Surely in buildrom, but also for manual builds...
> >
> > This is part of what should go away.  The BIOS has to get loaded at the
> > correct address for callbacks to work.  This loader needs to get loaded
> > somewhere else, then copy its payload to the right spot.  I'd love for
> the
> > loading part to get taken over by Coreboot.  Then we could just set up
> the
> > CMOS values separately and not depend on being loaded into a hard-coded
> > location in RAM.
> 
> Can you elaborate? What would coreboot need to do exactly (in addition
> what we already to for other payloads)? Is any of that board-specific?
> 
> What do you mean with CMOS values here? Where are they used in ADLO?
> Not yet, but you plan to do later?

They are the way the Bochs BIOS knows what device to boot from, what the
memory map is, etc.

> 
> > > This is needed for ADLO but not legacybios? Can we also change ADLO
> > > to not require it, or is that impossible?
> >
> > I hope someone will do it soon.  It would take me some time, since I'm
> not
> > really familiar with assembly, but it really isn't too much code.
> 
> OK, sounds good. So there's not _real_ reason to continue using it.
> 
> 
> > > Let's use "ADLO" in strings everywhere, as that seems to be the
> > > "official" name.
> >
> > Sure.  Once we replace the loader there will be nothing left of the
> original
> > but the name, but the name's fine.
> 
> Hm, if it's completely gone later, I think we should also eliminate
> the ADLO name (but not just yet).
> 
> It's just coreboot+legacybios then, correct? So we'll probably call
> it legacybios (or BOCHS BIOS?). We'll see...
> 
> 
> > > > Index: packages/legacybios/legacybios.mk
> > > > ===================================================================
> > > > --- packages/legacybios/legacybios.mk	(revision 0)
> > > > +++ packages/legacybios/legacybios.mk	(revision 0)
> > > [...]
> > > > +LEGACYBIOS_TARBALL=legacybios-$(LEGACYBIOS_TAG).tar.gz
> > > > +LEGACYBIOS_SOURCE=legacybios-$(LEGACYBIOS_TAG).tar.gz
> > >
> > > Why are both needed?
> 
> Is this required?

I took one out of the last patch
> 
> Testing the code now in QEMU and hardware, will report back.

Great.  Thanks,
Myles