Mac PowerPC: how to shrink a partition to make room for FreeBSD?

[tingo]

I got myself an iBook (used) for cheap, and I want to install FreeBSD on it. But I also want to keep a small partition with OS X on it. The machine cam with OS X 10.4.11 installed on the hard drive, but didn't come with install media.

So I thought, I'll just shrink the OS X partition (currently there is only one partition on the hard drive) to make room. Well, it turns out that the diskutil method (from OS X) doesn't work on PPC Macs:

$sudo diskutil resizeVolume disk0s3 limits
Error obtaining resizing information

Resizing encountered error Could not modify partition map (-9986) on disk disk0s3 Macintosh HD

Note: this was done with OS X booted off an external drive (firewire)
And gparted seems to be only for x86-compatible machines...
Does anyone know a way to shrink a partition on a PPC Mac?

 

[tingo]

Update: I got this suggestion on the freebsd-ppc mailing list:

If you have a Mac running 10.5 or 10.6 and can put the iBook into FireWire target disk mode, then you should be able to live partition the drive.

And I have a PowerBook G4 running OS X 10.5.x. First I powered on the iBook while holding down "T" on the keyboard (this selects target mode). You will know when the machine is ready, because you will have a large firewire symbol moving slowly around the screen. Then I connected the machine to the PowerBook with a firewire cable, started Disk Utility on the POwerBook and selected the external drive (firewire). I could then easily resize the OS X partition on that drive by dragging it to a lesser size, and pressing the "do it" button (or "execute" or whatever it is called in English). Nice!
Verified that the iBook OS X install still worked by booting up in OS X again - all good.