Re: [Qemu-devel] Boot order problem and disable iPXE/gPXE

[Gleb Natapov <gleb@redhat.com>]

On Thu, Jan 05, 2012 at 09:05:39PM -0500, Kevin O'Connor wrote:
> On Thu, Jan 05, 2012 at 11:20:37AM +0200, Gleb Natapov wrote:
> > On Thu, Jan 05, 2012 at 10:09:44AM +0100, Gerhard Wiesinger wrote:
> > > But as far as I remember therefore the option ROM registers through
> > > BIOS for INT 19h booting. So Seabios should know it that this is a
> > > harddisk.
> > It registers BEV. Otherwise you wouldn't be able to boot at all. In fact
> > it registers multiple BEVs (one for each attached scsi device). But BIOS
> > knows nothing about the device behind the BEV. It just jumps to BEV
> > address to boot from it when INT 19h is called. There may be scsi cdrom
> > there or even tape.
> 
> Gerhard's option rom is actually registering a BCV, and SeaBIOS can
> know that is likely a hard drive.  So, I think Gerhard has a point.
Ah, yeah. I see now that pnp rom can register either bev or bcv. But non
of them tell us what device it actually is.

> SeaBIOS could probably fall back to the harddrive priority if it finds
> a BCV without an explicit bootindex priority.
The same option rom probably will register bcv for SCSI CD/DVD too. Also
are you sure pxe roms do not register bcv for network booting?

> 
> Gerhard - does the patch below improve things for you?
> 
> -Kevin
> 
> 
> --- a/src/boot.c
> +++ b/src/boot.c
> @@ -326,7 +326,7 @@ boot_add_bev(u16 seg, u16 bev, u16 desc, int prio)
>  void
>  boot_add_bcv(u16 seg, u16 ip, u16 desc, int prio)
>  {
> -    bootentry_add(IPL_TYPE_BCV, defPrio(prio, DEFAULT_PRIO)
> +    bootentry_add(IPL_TYPE_BCV, defPrio(prio, DefaultHDPrio)
>                    , SEGOFF(seg, ip).segoff
>                    , desc ? MAKE_FLATPTR(seg, desc) : "Legacy option rom");
>  }

--
			Gleb.