Re: [Qemu-devel] [PATCH] x86: Manage BIOS boot menu via command line

[Anthony Liguori]

Paul Brook wrote:
> On Thursday 18 December 2008, Jan Kiszka wrote:
>   
> > When booting a guest from the command line, you normally do not need the
> > interactive boot menu with its 3 s waiting that someone might press F12.
> > So this patch introduces a mechanism to enable the boot menu only on
> > demand, ie. when the user provided the command line switch -bootmenu.
> > This reduces boot times to their original dimension.
> >
> > The host-guest interface used here is CMOS RAM byte 0x60. If it is
> > non-zero, the guest BIOS will skip the F12 delay, keeping the previous
> > behavior in case the host does not support it. -bootmenu was chosen in
> > favor of -boot as the syntax of the latter is not easily and cleanly
> > extensible.
> >     
>
> I'm not sure I believe this. We already support multiple options to -boot so 
> why not just add another one (e.g. "q") that means include the boot menu?
> i.e. -boot qcad would give the current behaviour.
>   

Or -boot cad,prompt=[on|off]

> I've no particular preference whether this is communicated to the bios via the 
> current 0x3d region or via a new byte. It looks like there's a spare bit in 
> byte 0x38 that could be used.
>   

Or firmware config since that can be shared with non-x86 targets.

Regards,

Anthony Liguori

> Paul
>
>
>