OpenSuse Portable

I have open suse on my external hard drive and it works really well!

opensuse 11.1

and I have a partion of free space where i want to to partition it for a mac hfs+ filesystem.

the problem i have is that grub keeps booting to my root partition that was the hfs+ not my root partition.

How can I format or make an hfs+ readable on a mac from open suse

and how do I boot grub to also remember to boot only from the root partition?

I also have super grub disk if that helps.!

Please Help,