In order to chain boot though BIOS emulation provided by Apple, I will deploy following boot sequence and partitioning here: EFI boot system -> rEFIt program ->+ +<-------------------------------+ +--> Mac OS X on /dev/sda2 (by rEFIt directly) +--> Linux testing on /dev/sda5 (via GRUB 2 MBR located on /dev/sda) +--> Linux amd64 on /dev/sda3 (via GRUB 2 BR located on /dev/sda3) +--> Linux i386 on /