18.06.2012 23:14, Bastian Blank wrote:
> Package: seabios
> Version: 1.7.0-1
> Severity: wishlist
> Please enable Xen support in seabios. It will be used by the next Xen
> release and maybe the version in Wheezy.
Do you know what's the outcome of this? As far as I remember, it is just
a config option, but it is not enabled by default, do you know why?
Kevin, can you comment please?
The following are a few issues discovered in the course of investigating
Debian bug #678042 , including the fix for that actual bug (which is
cause by Xen not supporting SMM mode).
The following changes since commit 9166c4ae6d21d49bd97e0fb42eea2ffd6dd6f06d:
Xen: add definition of xen_hypercall_page (2012-06-27 21:07:24 -0400)
are available in the git repository at:
Ian Campbell (3):
enable Xen support by default.
Xen: Autodetect debug I/O port at runtime instead of via Kconfig
SMM: Disable use of SMM when running under Xen
src/Kconfig | 9 +--------
src/output.c | 4 +++-
src/smm.c | 3 +++
src/util.h | 1 +
src/xen.c | 6 ++++++
5 files changed, 14 insertions(+), 9 deletions(-)
Fred . wrote:
> I don't have any serial debug log.
As you know, it would be helpful and a great way for you to
contribute if you produced one. Saying that something doesn't
work and nothing else is on the other hand not helpful at all.
Fred . wrote:
> when I tried it under QEMU it did not work
So what happens? What does the serial debug log look like? If you
don't provide details about the problem it is impossible to give
Please read http://www.chiark.greenend.org.uk/~sgtatham/bugs.html
I noticed that SeaBIOS fails to boot from virtio disk smaller than 512K.
The attempt to access a disk fails at basic_access().
(cylinder >= nlc || head >= nlh || sector > nlspt) is true because nlc
is zero. The problem seams to be in how SeaBIOS calculates lchs from
pchs in get_translation(). Both QEMU and SeaBIOS fake disk geometry from
real disk size, but it seams that they do it differently and when they
disagree part of the disk may not be readable.
What would be the best way to fix that?
I am trying to determine if there are legacy applications or operating
systems that invoke standard BIOS real-mode interrupt handlers while
in 16bit protected mode. (The legacy real-mode entry points - like
"int 0x13" - not the declared 16bit protected mode entry points
defined by the PnP and APM specs.)
I am considering changes to SeaBIOS that would make 16bit protected
mode callers much less likely to work. (Specifically, enhancing
SeaBIOS to use memory in the e-segment which is unlikely to be mapped
in protected mode.)
Most documents I've seen state that calling the real-mode entry points
in protected mode will not work. Though, I am aware that the PCI BIOS
spec specifically requires this support for calls to "int 0x1a
The advantage of making these changes is that it will allow SeaBIOS to
use notably less stack space and therefore be more compatible with old
applications that call the BIOS with very little stack space. For
example, these changes enable DOS 1.0 to boot and run under SeaBIOS.
What would really help is pointers to applications and/or program
images that use 16bit protected mode calls to real-mode entry points.
Specifications or documents detailing valid or invalid uses would also
For those that are willing to run tests, one can compare the standard
SeaBIOS v1.7.0 image (for KVM/QEMU) at:
to a test image with the new code at: