Triple Boot on MacBook Air

Update - 8/14/2012: I've since wiped my MacBook Air Linux and Windows partitions. I just wasn't using them enough. Windows 8 completely strikes me as a mess of an operating system. I may come back to post step by step instructions as I do this again with the final version of Windows 8.

This post is a work in progress, bear with me...

I successfully have a triple boot with Mac OS X, Windows 8 Release Preview, and Gentoo Linux again on my MacBook Air. I used to have a triple boot on my old MacBook 13 inch with Snow Leopard. However, Lion changed everything. With the introduction of the Lion recovery partition, triple booting legacy operating systems that depend on BIOS emulation was no longer possible. This is because you cannot have a hybrid GPT/MBR partition with more than four partitions. GPT partition schemes don't understand extended partitions and MBR partition schemes cannot have more than four primary partitions. Mac OS X Lion now takes up three of those partitions with a default install. You've got the EFI partition, the Mac OS HFS+ partition, and the recovery partition. You've only got one left if you want to boot a legacy OS alongside Mac OS X.

I dreamed for the day when Windows could successfully EFI boot on a Mac. I tried it with Windows 7 and it failed miserably. I can't remember if I tried it with Windows 8 Consumer Preview at all. I guess I figured that Apple had to change their EFI implementation from version 1.1 up to UEFI 2.0. Apple still uses a wacky non-standard EFI. They haven't changed anything there. However, I decided to attempt an EFI boot from a USB Windows 8 installer to see what would happen. It worked fine! With Windows now able to boot and install on my MacBook Air in EFI mode, I resurrected my old EFI enabled Gentoo Linux image and restored it to an additional partition. All operating systems are booting and running just fine now.

In the coming days I will post the exact steps I used to achieve this. The only drawback is that Windows cannot use an accelerated video driver when booted in EFI mode on the Mac. If I don't plan on playing games on my Mac under Windows then it shouldn't be a problem, though.

Stay tuned...