[SeaBIOS] reboot fails with QEMU "isapc" machine type

Daniel P. Berrangé berrange at redhat.com
Fri Feb 9 11:49:17 CET 2018

On Wed, Feb 07, 2018 at 09:34:59PM -0500, Kevin O'Connor wrote:
> On Mon, Feb 05, 2018 at 12:46:41PM +0000, Daniel P. Berrangé wrote:
> > I was experimenting with old MS-DOS 6.22 under QEMU with the 'isapc' machine
> > type, and found it is not able to reboot the guest. Bisecting QEMU blamed
> > the QEMU change that rebased from "rel-1.9.3", to "rel-1.10.0". Further
> > bisecting SeaBIOS blames this change:
> What version of QEMU are you using?  I can't get anything to run with
> the isapc machine type - I just get:

I've tested many QEMU versions when trying to narrow it down,
including current git master.

I'm building current GIT master on Fedora 27, using:

  ./configure --target-list=x86_64-softmmu --disable-xen \
  make -j 8
  make install
  $HOME/usr/qemu-git/bin/qemu-system-x86_64 \
         -fda ~/FLOPPY.img -monitor stdio -M isapc,accel=tcg

Where 'FLOPPY.img' is the FreeDOS download from


That's an installer image - just wait till it displays the
first install screen to "select a language".

Then in the QEMU monitor console I do

  (qemu) sendkey ctrl-alt-delete

> I didn't think isapc was functional at all.

Yep, it should work, within limits of its feature set of course.

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