On Mon, Jan 21, 2008 at 08:30:25PM +0100, Pavel Cahyna wrote:
> On Tue, Jan 15, 2008 at 10:15:59PM +0000, Manuel Bouyer wrote:
> > 
> > Module Name:	src
> > Committed By:	bouyer
> > Date:		Tue Jan 15 22:15:59 UTC 2008
> > 
> > Modified Files:
> > 	src/sys/arch/i386/include [bouyer-xeni386]: pmap.h
> > 	src/sys/arch/x86/x86 [bouyer-xeni386]: pmap.c
> > 	src/sys/arch/xen/x86 [bouyer-xeni386]: x86_xpmap.c
> > 
> > Log Message:
> > Snapshot of work in progress: an Xen i386PAE kernel boots and start init
> > on a amd64 dom0, but panics when init forks.
> > This code needs a lot of cleanup, and the pmap handling is minimal to
> > allow init to start. It's a proof of concept of how PAE on Xen can work.
> > 
> > For PAE guest, the Xen MMU handling differs in some significant way
> > from the i386 or amd64 Xen.
> > The L3 page has only 4 entries, the last one mapping 0xc0000000->0xffffffff
> > (which happens to be our kenrel VM range, that's cool).
> 
> Unless you define options KERNBASE.

I think setting it to a smaller value should work. Setting it to something
larger than 0xc0000000 will be a real pain to support for PAE.
Linux also has the kernel loaded at 0xc0000000, and the PAE support in
Xen was really designed for this case.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--