[coreboot] [PATCH] Convert all Intel i810 boards to CAR

Uwe Hermann uwe at hermann-uwe.de
Fri Oct 15 00:27:30 CEST 2010


On Thu, Oct 14, 2010 at 08:58:35AM -0700, Stefan Reinauer wrote:
> On 14.10.2010, at 05:38, Joseph Smith <joe at settoplinux.org> wrote:
> >> 
> > Anyways why can't cpu specific features be implemented at the model level and not at the socket level???
> 
> Because SSE, SSE2 and MMX are not CPU specific features in this context. SSE and MMX determine how many registrers are available for romcc. It describes the lowest common denominator between all CPUs in a socket. If one model selects SSE and another one does not, it will still be enabled, thus breaking every other CPU you can put in that socket. 

Yep.

 
> Maybe we should drop those flags from Kconfig completely and just set the right ROMCCFLAGS in the socket's makefile to remove any confusion about the meaning of thos flags.

It's worth considering IMHO, yes. Or, actually, since sooner or later
many chipsets will convert to TINYBOOTBLOCK and CAR (at least that's the
plan I think), romcc will only ever be used for the bootblock, right?

And that's pretty tiny hopefully and should work just fine with 386
as romcc option? Do we actually really have any measurable advantages
from using romcc options other than 386 in that case?

Same for RAM test -- it's not a memtest86 replacement, just a quick
"Did I screw up RAM init" test, which doesn't get run very often after
the RAM init code is finished / working. Does the RAM test speed really
matter much here? Shall we just use 386 for ROMCC everywhere (and not
use SSE2 for ramtest) and get rid of the MMX/SSE/SSE2 config options?


Uwe.
-- 
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