Re: [PATCH 1/2] qemu-kvm: extboot: Keep variables in RAM

Kevin O'Connor
2010-02-20T03:21:49Z

On Fri, Feb 19, 2010 at 11:37:04AM -0800, H. Peter Anvin wrote:
> On 02/19/2010 10:17 AM, Jan Kiszka wrote:
> >>
> >> Stefan posted a virtio-blk driver for gPXE. I like this approach
> >> because it's generally useful (gPXE can be used with any BIOS).
> >
> > Does it allow a unified boot device selection, one menu for them all, no
> > more "boot=on" workarounds?
> >
>
> Well, it hooks into BBS if the underlying BIOS supports it. Without BBS
> there is no ability to have a unified boot device selection.

SeaBIOS does support BBS (both BEVs and BCVs). Also, under qemu,
SeaBIOS will run option roms with memory writable and then lock the
memory after the POST phase (as is required by the spec).

SeaBIOS also support PMM (both temporary allocations and the PCIv3
extensions for permanent memory).

Finally, I plan to commit a series of patches to SeaBIOS which add
support for booting from USB drives. I imagine adding virtio support
to SeaBIOS would not be difficult if someone wishes to take that on.

-Kevin