[SeaBIOS] [Qemu-devel] Re: Need a way disable gPXE boot

Richard W.M. Jones rjones at redhat.com
Wed Mar 10 10:51:41 CET 2010


On Tue, Mar 09, 2010 at 09:03:41PM -0500, Kevin O'Connor wrote:
> On Tue, Mar 09, 2010 at 02:11:20PM +0000, Richard W.M. Jones wrote:
> > I noticed also with libguestfs that boot times have spiralled out of
> > control again, and it seems to be down to the SeaBIOS change.  SeaBIOS
> > accounts for _9_ seconds of the boot sequence, up from very small
> > (fraction of a second) for the old Bochs BIOS[1].
> 
> I'm surprised - a significant amount of effort has gone into making
> SeaBIOS boot quickly.  On my machine, the OS starts loading in well
> under a second.

By a process of elimination, last night I worked out that the change
is down to the following option ROMs:

  gPXE (not sure which exactly): 5 seconds
  pxe-virtio.bin: 4 seconds

I can't find the source for the latter, but it seems neither is part
of SeaBIOS, but are added from other sources by the Fedora build of
qemu.

I built a custom version of SeaBIOS [nicely documented code BTW, once
I'd read the README file it was very simple to understand and
customize!] which booted in under a second.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines.  Supports shell scripting,
bindings from many languages.  http://et.redhat.com/~rjones/libguestfs/
See what it can do: http://et.redhat.com/~rjones/libguestfs/recipes.html



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