On Wed, Aug 22, 2007 at 05:37:11PM +1000, Daniel Carosone wrote:
> On Tue, Aug 21, 2007 at 09:52:46AM +0200, Manuel Bouyer wrote:
> > debug will probably give usefull hints, but you may need a serial console
> > for this as I'm not sure it'll print anything usefull on VGA (I only use
> > serial consoles so I don't know :)
> 
> So, I tried a bunch of boot-option variations in an attempt to 
> provoke something different or narrow down something that might
> be causing it.
> 
> No variations with xen boot options had any effect: nosmp, noapic,
> nolapic, hap, etc.  Turning on extra loglvl, or using the xendebug.gz
> VMM didn't reveal anything new either.
> 
> For all of these options, the dom0 kernel is loaded and the memory map
> is printed, the debug log levels for xen and guest are printed, and
> that's it..  a few second's pause then back to the bios splash screen.
> If I boot xen with "noreboot", there is no reboot - but there is no
> further information or messages either. It just seems to stop at the
> same point.  Nothing is ever printed that I can see from the NetBSD
> kernel - no Copyright or anything more.
> 
> This seems suggestive that there's some kind of error when starting
> the dom0 kernel that Xen detects and triggers the reboot. However 
> I'm just so far unable to provoke any further diagnostics about what
> that error might be.

Xen should print something on the serial console if it reboots
the box by itself. If there's nothing printed, then it looks more
like a triple-fault or something like that.
How much RAM does the box have ?

> 
> If the problem is with the kernel, it's not my kernel config: I built 
> a XEN3_DOM0 kernel and it behaves identically.  I tried changing
> compiler settings (optimisation, -march=, etc) also with no result.
> 
> I'm travelling at the moment, with limited bandwidth and very limited
> hardware to test any other permutations to narrow down further -
> problems with my source, tools or something specific to the
> hardware/bios/something on the host.
> 
> I've uploaded this XEN3_DOM0 kernel to ftp:/pub/NetBSD/misc/dan -
> either you'll be able to reproduce the problem with this kernel, and
> we can look at problems with source or toolchain, or you can't and
> there's something odd about my machine or memory layout or bios or
> ... *shrug*.

Unfortunably my office is being moved this week, so all my test system
are unavaible for now :( I'll try it as soon as I have access to my
office again.

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