[coreboot] [PATCH] more Kconfig default fixes

[Myles Watson]

> Myles Watson schrieb:
> > Fix AP_CODE_IN_CAR (only selected for two boards), STACK_SIZE, and
> HEAP_SIZE.
> >
> > Signed-off-by: Myles Watson <mylesgw at gmail.com>
> >
> > At this point my Tyan s2895 is happy with Kconfig.  Boot tested.
> >
> > Thanks,
> > Myles
> >
> Looks (almost) good to me but I'd prefer someone else to check it, to.
I was figuring that Patrick's scripts will check this stuff and we'll get
closer and closer to newconfig.  There are a few values things that I'd like
to not match newconfig, though.  For example, fam10 and k8 had different
cache as RAM settings in newconfig, and they could share them.

> One thing though: We're using lzma per default now if we're using
> compression. This means each board needs at _least_ a stack size of
> 0x8000.
Why does LZMA use so much memory from the stack?  Couldn't we convert it to
use heap so that it is easier to tell when you run out?  I guess that would
make it dependent on a malloc call?

> Those boards with STACK_SIZE being 0x2000 or 0x8000 are definitely
> broken (and if they boot, they do by accident)

So since it's broken with Kconfig and newconfig, how can we decide what the
correct stack size should be?

What's the downside of a large stack?
What breakage should occur, heap corruption?
Should we check before LZMA how much stack is left?

Thanks,
Myles