mac os upgrade dual boot setup

Ok I have a dual boot mac g4. i wanted to upgrade to leopard
so i noted that the hard drive partition setup is
/dev/hda1 Apple_partition_map
/dev/hda2 bootstrap yaboot
/dev/hda3 swap
/dev/hda4 Linux / 15.6G
/dev/hda5 Mac OsX 11.8G


so then i booted into new leopard installer disk, wiped out old Tiger, reinstalled from scratch to mac partition
then i did
power on
hold down apple,option, o,f buttons (yes 4 buttons)
then at > prompt type
>boot hd:2,yaboot

here 2 is /dev/hda2 ie yaboot bootstrap partion
then type
>Linux
then

Login to linux system
run as root
fdisk -l
and look to what the macosx partition is

ON my system it changed from /dev/hda5 to /dev/hda6!!! with the new install, wasting a good 120M of space on the drive...

Then edit /etc/yaboot.conf to set
macosx=/dev/hda6 or whatever

then as root run
ybin
this will reinitialize the boot sector to boot to yaboot and
choose Linux as default or Leopard.

Then install OsiriX to MacOsX partition :)