semthex from Hackint0sh.org, in collaboration with AppleTVHacks.net has done it again! A complete replacement to the Mac OS X kernel has been built which allows the full version of Mac OS X to be run on an Apple TV.

Semthex wrote a processor emulation for the kernel, to sidestep the hardware restrictions that previously disallowed Mac OS X from running on the Apple TV. AppleTVHacks.net was only too happy to help out, and when it turned out we needed more testers we launched a competition to get some. Within hours we had hundreds of eager Apple TV hackers submit entries.

Several hours of testing and refining later and our tester, gimli, managed to follow the steps (included below) to get Mac OS X booting on his Apple TV (click to enlarge):

The Apple TV running Mac OS X can use the mouse and keyboard normally, and you can run regular OS X apps easily. You can use either Front Row or Back Row (or Joost, or VLC, or…) to watch content, and can use it for most things you would use a Mac for.

Tester, mk500, made a video to demonstrate it all working:

How to install

This is the process that was used to turn the Apple TV into a full blown Mac OS X machine:

1) remove the drive from the Apple TV

2) back up your drive! Make an image of it (see the harddrive upgrade tutorial for this)

3) Connect the drive to a regular Mac (use a Firewire or USB drive dock)

4) Install OS X (Intel version) to the drive (we suggest a slim install – no printer drivers etc.)

5) Boot from this drive, and set it up as you would like it. Make sure you do updates so it is at least 10.4.8.

6) Reboot to your normal OS X install.

Ok, you now have your fresh OS X install which will form the base of the customised OS X you will need for the Apple TV.

7) Remove mach_kernel from root of the drive containg the ATV install.

8 ) Replace it with the customised mach_kernel that you’ll find on Hackint0sh.org.

9) Replace /System/Libary/Coreservices/boot.efiwith the same file from your backup of the Apple TV OS drive (OSBoot partition).

10) Run bless:

bless --folder=/Volumes/OSBoot/System/Library/CoreServices --file=/Volumes/OSBoot/System/Library/CoreServices/boot.efi --setBoot

11) Delete all the Nvidia kexts (all beginning with NVD, there should be 5) from the target drive (in /System/Library/Extensions).

12) Transfer the drive back to the Apple TV

13) Turn the Apple TV on and cross your fingers.

You should boot up into Mac OS X. Woo!

Now what?

This hack seriously opens up the doors with what the Apple TV could be used for; and we imagine we are going to see lots of cool hacks, additions and addons. We will do our best to keep track of them.

A big thanks again to semthex over at Hackint0sh.org; who did the majority of the work, and built the custom kernel.

The brave testers who helped make this happen: gimli, mk500, Turbo, Jonathan Bare, l0rdr0ck.