pc-bios/bios.bin - where it comes from?

[Michael Tokarev <mjt@tls.msk.ru>]

Hello.

There are a few bugs filed about an.. interesting
behavour.  For example:

 http://www.mail-archive.com/kvm@vger.kernel.org/msg29834.html
 https://bugs.launchpad.net/qemu/+bug/513273

After quite some mix-n-matching, at least on my test machine,
I can say that the issue gets triggered by seabios.  When
using pc-bios/bios.bin everything is ok.  But when using
any other bios.bin, even downloading seabios-0.5.1.tar.gz
and building it - on a debian lenny system anyway - by
running `make', the problem triggers.

I tried different versions/variations of vgabios.bin
(it's only -vga std which triggers the issue so far),
including 0.6b and 0.6c built from sources, vgabios.bin
from debian packages (0.6b and 0.6c), and the one
included in qemu-0.12.3.tar.gz.  And my conclusion
so far is that vgabios.bin has exactly _no_ effect on
the issue.

But when using bios.bin from qemu-kvm-0.12.3.tar.gz,
and _only_ that bios.bin, the problem goes away.

So the question arises: where that pc-bios/bios.bin
comes from into qemu-0.12.3.tar.gz?  It is either
built from some other sources (not from seabios-0.5.1),
or built with some extra/different compiler/linker options,
or built using different compiler/linker.

This is partially confirmed on ubuntu as well, but,
as far as I understand, there the behavour is different
with different versions of vgabios.

In case it's not clear: I'm testing qemu-kvm-0.12.3;
bios.bin is the same in qemu-0.12.3 and qemu-kvm-0.12.3.

BTW, is there any reason preventing updating vgabios
to 0.6c version - the latest released one?

Thanks!

/mjt