i386/70525: [boot] boot0cfg: -o packet not effective

[Brian Candler]

On Mon, Dec 04, 2006 at 07:38:00PM +0100, Remko Lodder wrote:
> > I have not observed this directly in the MBR, but is based on the 
> > following
> > sequence:
> > 
> > - divide a 40GB HD into two primary partitions
> > - install FreeBSD in the first 20GB, with its bootloader in the MBR
> > - install OpenBSD in the second 20GB
> > - the FreeBSD bootloader then offers
> > 
> >   F1 FreeBSD
> >   F2 BSD
> > 
> >   but F2 just beeps (i.e. cannot boot OpenBSD)
> > 
> > - booting into FreeBSD and issuing "boot0cfg -Bv ad0" fixes the problem.
> > 
> > Therefore my guess is that the initial installation of the MBR is setting 
> > -o
> > nopacket, even though boot0cfg has -o packet as its default.
> > 
> > Also reported at
> > http://lists.freebsd.org/pipermail/freebsd-i386/2006-December/004892.html
> > 
> > Regards,
> > 
> > Brian.
> 
> Let's theorise here: can't this be,  because of the bootloader
> of freebsd is unable to detect any openbsd installation on the
> second partition simply because it isn't there yet? afterwards
> this can be found, resulting in the behaviour...

Are you saying that the FreeBSD MBR can only boot operating systems which
were installed at the time that the MBR was installed?

I don't think this is the case, because the MBR correctly detected both
partitions, and offered them to me:

   F1  FreeBSD
   F2  BSD

So it knows that ad0s2 exists, it knows that ad0s2 is bootable, and it even
knows what type of O/S is in that partition (presumably from the type code,
A6)

However, pressing F2 fails.

All it has to do is to load the boot sector from that partition, and jump to
it. I'm presuming that this requires the new 'packet' BIOS call when this
sector is located above the 1024-cylinder mark.

Regards,

Brian.