[fmma]

Here a solution how to boot OS-X and 'linux' (in my case !#chrunchbang) with grub2 in the
MBR.

Grub has changed to grub2 in most linux distributions

I read that installing grub in a partition is not advisable. So I installed first
1) OS-X
2) chrunchbang

with grub2 in the MBR.

Boot in linux and open a terminal (as root)

edit

/etc/grub.d//40_custom

The file should have the following lines:

#!/bin/sh
exec tail -n +3 $0

# entry to boot OS-X

menuentry 'OS-X' {
insmod hfsplus
set root=(hd0,2) #change according your partitition table
multiboot /boot
}

save and run as root

update-grub

reboot


Hope this helps