Re: [Qemu-devel] [RFC] gPXE fw_cfg file interface support

[Gerd Hoffmann <kraxel@redhat.com>]

> gPXE>  imgfetch fw_cfg:genroms/static.gpxe

Neat idea.  On the qemu side we better shouldn't abuse the -option-rom 
switch though as seabios will try to load these files as option roms.

> Note that this patch only adds the fw_cfg file interface mechanism, it does not
> automatically probe for a special file when gPXE starts.  You will
> need to manually
> "chain fw_cfg:genroms/file".

That should be changed too IMHO.  qemu needs some kind of new switch, so 
you can place the firmware file into some other virtual directory where 
gpxe could look by default, i.e. something like "fw_cfg:gpxe/default". 
Then you can easily have qemu guests netboot from somewhere without any 
local pxe/tftp setup, like this:

   qemu -fw-file gpxe/default=bko.gpxe

with bko.gpxe being:

   #!gpxe
   dhcp net0
   set 209:string pxelinux.cfg/default
   set 210:string http://boot.kernel.org/bko/
   chain http://boot.kernel.org/bko/pxelinux.0

cheers,
   Gerd