[gPXE] [Qemu-devel] Stack corruption problem with SeaBIOS/gPXE under QEMU

[Kevin O'Connor]

On Sat, Nov 14, 2009 at 02:47:45PM -0500, Kevin O'Connor wrote:
> On Thu, Nov 12, 2009 at 01:20:58PM +0200, Naphtali Sprei wrote:
> > I've found a problem with the usage of SeaBIOS/gPXE in Qemu.  The
> > scenario is when failing to boot from network and falling back to
> > booting from hard-disk (-boot nc).  The cause of the problem is that
> > both SeaBIOS and gPXE (in it's installation phase) uses same stack
> > area, 0x7c00.  The gPXE code corrupts the SeaBIOS stack, so when
> > gPXE returns to SeaBIOS chaos occurs.
> > 
> > Output: "qemu: fatal: Trying to execute code outside RAM or ROM at 0x00000000eb300000"
> 
> Thanks for reporting this.
> 
> We can move the SeaBIOS stack, but it's not clear to me where to move
> it to.

I don't think this is a SeaBIOS bug, but in an effort to move forward,
I've moved the SeaBIOS stack from 0x7c00 to 0x7000.  Commit 494dfc6e.

-Kevin