cvs commit: src/sys/conf ldscript.i386 src/sys/i386/i386 bios.c genassym.c locore.s machdep.c mp_machdep.c mpboot.s pmap.c src/sys/i386/include pmap.h vmparam.h

[Peter Wemm]

John Baldwin wrote:
> 
> On 04-Oct-2003 Peter Wemm wrote:
> > John Baldwin wrote:
> >  
> >> On 01-Oct-2003 Peter Wemm wrote:
> >> > peter       2003/10/01 16:46:08 PDT
> > 
> >> >   Log:
> >> >   Commit Bosko's patch to clean up the PSE/PG_G initialization to and
> >> >   avoid problems with some Pentium 4 cpus and some older PPro/Pentium2
> >> >   cpus.  There are several problems, some documented in Intel errata.
> > 
> >> What does KERNBASE map to now?  4mb?
> > 
> > Nope.  KERNBASE is unchanged.  What is different now is that the fixed 1MB
> > offset (pa = 1MB, va = KERNBASE + 1mb) is now 4MB and available via the
> > KERNLOAD variable.  This becomes 2MB on a PAE configuration kernel.
> 
> So does KERNBASE + foo still map to PA foo for the lower 1 meg?

Yes, but the RAM part is readonly.  The isa hole and any ram->640K hole
and address zero is read/write.  There are no devices under the ram section
though, so the pmap_mapdev() tweaks for the first 1MB should be ok still.

Cheers,
-Peter
--
Peter Wemm - peter at wemm.org; peter at FreeBSD.org; peter at yahoo-inc.com
"All of this is for nothing if we don't go to the stars" - JMS/B5