multi-boot bootstrap?

[dieterbsd at engineer.com]

> Now, how are you going to multiboot OpenBSD and NetBSD on a PowerPC 
machine
> from the same hard disk.

I didn't say anything about a requirement for booting multiple OSes
from the same disk.  I said:

>> Go through all the disks and look
>> for bootable partitions.  Extract the GPT partition labels for
>> these partitions.  Present a menu of choices.

There can be multiple disks.  (Assuming the hardware supports that.)
I haven't worked with PowerPC machines and it has been a very long time
since I worked with Sparc.  I'm more familiar with Alpha, which would 
take
some hacking to boot more than one OS per disk, but some rocket 
scientist
decided to drop FreeBSD support for Alpha, so I suspect that no one here
cares about Alpha.

> From what I know, one or the other can only be as
> the first entry and it then has to be set from the forth prompt.
> So, you will need two disks to boot , saya: OpenBSD, NetBSD, FreeBSD, 
Linux,
> and MacOSX or a combination of these.
>
> On PPC boxes with OpenFirmware 3.x, you actually need to set the 
active
> partition if you want to boot Linux and/or freebsd from the forth 
prompt if
> both are on the same disk.

Can these PPC boxes boot from GPT disks?  "active partition" sounds 
MBRish.
Perhaps they can use the "protective MBR" trick?