[SeaBIOS] [PATCH 0/7] vgabios improvements

David Woodhouse dwmw2 at infradead.org
Mon May 19 21:23:25 CEST 2014

On Wed, 2014-04-16 at 12:37 -0400, Kevin O'Connor wrote:
> On Mon, Apr 14, 2014 at 02:22:51PM +0200, Gerd Hoffmann wrote:
> > So you can try this:
> > 
> > qemu -vga std
> -bios /usr/share/coreboot.git/coreboot-i440fx-seabios.rom
> > 
> > to see it live in action.
> > 
> > Two problems spotted so far:
> > 
> >   (1) ipxe hangs at rom load time.
> >       can be worked around by adding '-net none' to the qemu cmd
> line.
> I've reproduced this.  It only fails for me with -enable-kvm.  It was
> (as I feared) the result of segment limits getting trashed from the
> int 1587 call.  (Presumably, qemu tcg doesn't fail because it doesn't
> implement segment limits?)  The (incorrect) patch below enables the
> boot to proceed past the ipxe prompt.
> This is unfortunate.  I can put a hack into seabios (not seavgabios)
> to use bigreal mode for int 1587 calls during option rom execution.
> But, it does raise the question of how many other callers expect the
> bios to not mess with the segment limits.  (Though, to be honest, the
> only goal I have with coreboot native seavgabios is support for grub,
> lilo, syslinux, and maybe ntldr.)

Was there a conclusion to this? Did you eventually convince yourself
that it could be *OK* for the video BIOS to trash the segment limits,
for a limited set of boot targets?


-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/x-pkcs7-signature
Size: 5745 bytes
Desc: not available
URL: <http://www.seabios.org/pipermail/seabios/attachments/20140519/914aadeb/attachment-0001.bin>

More information about the SeaBIOS mailing list