PowerPC, gpart and multiboot (Was: Trying to install FreeBSD 8.2-RC1 on a PowerMac G5)

[Torfinn Ingolfsen]

Anyway, here is my plan for multiboot:
root at kg-g5# gpart show ad0
=>       18  625142430  ad0  APM  (298G)
         18       1600    1  apple-boot  (800K)
       1618  155189248    2  freebsd-ufs  (74G)
  155190866    8388608    3  freebsd-swap  (4.0G)
  163579474       1600    4  apple-boot  (800K)
  163581074  155189248    5  freebsd-ufs  (74G)
  318770322  306372126       - free -  (146G)

The boot code in partition 4 (ad0s5) will be modified so that it boots from
the next partition (the partition after the one the bootcode itself is loaded from) 
instead of the first partition. Do you think it's doable?

I have examined boot1.c (in /usr/src/sys/boot/powerpc/boot1.chrp) but I don't
really understand how it is finding the partition to boot / load the kernel from.

Can anyone explain it?
-- 
Torfinn