HOWTO: Boot Mac OS 10.4.8 on an AppleTV without opening the case

Goal: Boot up Mac OS X on an AppleTV from a USB drive without voiding warranty. This is done to allow the user to install hacks on the AppleTV internal drive itself.

Credits:
Modified Kernel by semthex [http://www.semthex.com/]
Partitioning portions taken from Turbo's "Creating a disk to boot from USB" notes [http://0xfeedbeef.com/appletv/]
Portions of this guide taken from semthex's "Mac OS X running on Apple TV" howto
Small portions written by Paul Taylor [http://www.addressplus.net]

Required materials:
An AppleTV
A boot.efi file from an AppleTV (don't ask me where to find this)
Intel Mac
Tiger Install CD
External USB 2.0 hard drive

Set up your USB drive
1. In Mac OS, open Disk Utility
2. In the left pane of Disk Utility, select the USB drive
3. Hit the Options button at the bottom of the screen.
4. On the resultant screen, select GUID Partition Table. This is required to be able to install Mac OS X.
5. Lay out your partitions the way you want.. (One big, two, whatever) and format them with Mac OS Extended (Journaled)
6. Let the format finish. When done, you should be able to mount the drive.

Install Mac OS X
1. Pop in your install disk with the external drive attached
2. Reboot, holding down the Option key on your keyboard
3. Select the CD icon to boot from your install CD
4. Run through the complete installation process, selecting your USB drive as the destination.

Customize your USB installation
1. Run through the normal 1st boot stuff (Add user, etc.)
2. Download this: http://www.apple.com/support/downloa...dateintel.html
3. Install the 10.4.8 combo update
4. Reboot. Go to software update and get all the updates EXCEPT 10.4.9
5. System Prefs > Sharing
6. Check Remote Login here (this enables SSH)
7. Check Apple Remote Desktop
8. Click "Access Privileges", check the "VNC viewers" box, and put in a password here. This will let you remote control your AppleTV after you boot it with this installation.
9. Do any other customization you desire, except update to a newer version of Tiger

Get ethernet working with PCGenRTL8139Ethernet 1.2.0
1. Download http://www.sendspace.com/file/4i62j1
2. Install per the instructions in the file
(Note: This is needed to get either the built-in Ethernet to work or the Airport. This doesn't break Ethernet support for an Intel Core Duo iMac - not sure about others.)

Install proper kernel
1. Boot back up to your internal hard drive
2. Download the kernel from one of the mirrors listed here:
http://www.hackint0sh.org/forum/showthread.php?t=541
3. Mount your external drive
4. From a Terminal window, do this: ls -la /Volumes/YourExternalDisk
5. You will see a file called mach_kernel there.
6. Delete this file (may have to sudo rm /Volumes/YourExternalDisk/mach_kernel). Be careful here NOT to delete the kernel on your Internal Boot disk!
7. Copy the unzipped kernel you downloaded in step 2 to /Volumes/YourExternalDisk

Install boot.efi
1. Replace /System/Library/CoreServices/boot.efi with the boot.efi file from the AppleTV boot drive (it is in the same path)
2. To do the above, you may have to do a "Get Info" on the boot.efi file on your external drive and uncheck the "Locked" checkbox.
3. Bless the installation from a Terminal:
sudo bless --folder=/Volumes/YourExternalDisk/System/Library/CoreServices --file=/Volumes/YourExternalDisk/System/Library/CoreServices/boot.efi --setBoot

Cleanup
1. Delete the Nvidia kexts (all begining with NVD, there are 5) from /Volumes/YourExternalDisk/System/Library/Extensions
2. Delete /Volumes/YourExternalDisk/System/Library/Extensions.mkext and Extensions.kextcache if they exist

Patch AppleFileSystemDriver
NOTE: Perform these steps with a command line text editor or with TextWrangler (http://www.barebones.com/products/te...ownload.shtml). DO NOT USE TEXTEDIT!
1. Edit /Volumes/YourExternalDisk/System/Library/Extensions/AppleFileSystemDriver.kext/Contents/Info.plist
2. Search for "IOPropertyMatch". It will be found similar to this:
3. Just after the line with <array>, copy/paste this in:
Change Partition Type
NOTE: Once you do this, you can't mount the disk on your Intel Mac anymore without reversing the change. If you mess up here, you'll need to start over.
1. Open Disk Utility
2. Select the external disk from the left pane. Right click and select "Information"
3. Take note of the "Disk Indentifier". In my case, it is "disk3". For safety reasons, the rest of this guide is written with "diskX". Replace the X with the number of your drive.
4. From Terminal:
gpt -r show /dev/diskX
5. You'll get something similar to this back:
6. A little explanation here is in order. The first real partition is on the line beginning with 40. In this case, it runs from 40 through 409600. (I'm guessing these are bytes) Next to the size is the index, 1. The very next line is the one we are interested in. This is the partition that contains your bootable install. It is index 2. You may or may not have and index 3)

7. Unmount the disk:
disktool -u diskX

8. Now, we remove the entry in the table for the 2nd partition
gpt remove -i 2 /dev/diskX

I got this back:
gpt remove: /dev/disk3: 1 partition(s) removed

9. Mac OS will remount any remaining partitions. Unmount them:
disktool -u diskX

10. Now, we add a new entry to the table. For index 2, take note of the start, and the size, as you'll need them here. Replace the START and SIZE strings with your values.

gpt add -b START -s SIZE -i 2 -t "5265636F-7665-11AA-AA11-00306543ECAC" /dev/diskX

Note that it doesn't tell you anything back.. You just get a prompt.

11. Performing step 5's command again gets me this:
Note that the index 2 partition type is now the required type for AppleTV to boot to.

Boot your AppleTV with OS X
1. Attach your external drive to the USB port
2. If already booted up, hit MENU and "-" on your remote and hold it until a reboot start
3. If your AppleTV isn't on, plug it in to power. No remote finagling required.
4. Watch in AWE as your AppleTV boots up OS X.

Thanks, ptaylor874. I followed the instructions exactly except for one step: I did not replace boot.efi from the appleTV, because to do so would require me to open the case and void the warranty.

Of course, the appleTV did not boot from external HD without this step. So, this boot.efi is really the missing piece in all of this -- everything else is freely available and understandable.

I know that you said not to ask where to get boot.efi. I just want to clarify that this boot.efi file looks to be critical for success with these instructions.

Yes - That file is absolutely critical to get it to work.

You may be able to convince a friend to buy an AppleTV and borrow it for an evening, extracting the boot.efi file from his... That way your warranty would be completely in tact..

Thanks for this guide :-D Realoly great work.

__________________

Works beautifully....

http://www.flickr.com/gp/51035591025@N01/X40Bt4

Hmm that means booting from a USB thumb drive might be possible.

I attempted this with an install from my brand new (two weeks old, 10.4.8) MacBook Pro restore DVD, and when I tried to boot up, I was presented with the grey apple, then with the "invalid" sign (circle with a line through it), and the drive failed to boot. I tried the install again with the same results.

Am I doing something wrong, is my DVD too new?

This happened to me too. I just rebooted it again... and then it showed me the Apple Logo... then it rebooted automatically *again* ... and then booted up to the Mac OS just fine thereafter...

So just keep rebooting it I guess... let it grind away~

*****

Question about boot.efi

I don't want to void my warrentee either with my Apple TV... Is a boot.efi file unique to each ATV? If it's not, then what's keeping people from providing it online...? Or should I not be asking that question...?

Thanks,

Eugene

DxQ,
I don't know what the problem could be. If you are replacing the kernel with the semthex kernel, deleting the specified files, and handling the boot.efi as directed, it should work as long as you don't run into an issue with the partitioning.

Yujean,
The boot.efi file is not unique to an individual AppleTV, as far as I know.

With that in mind, I guess that it, or perhaps even a copy of the AppleTV OS that you could pull it from, may be somewhere on the Internet.

Whether it would be legal to download it is another question... I'm almost of the opinion that you could get away with it legally since you own an AppleTV box, but what do I know? I'm not a lawyer.

One good bit of news that I read last night was that Apple wasn't planning to do anything to stop people from hacking their AppleTVs.

I am following the given instructions EXACTLY, and I've done it twice.

I am not using the boot.efi from my image, as I haven't opened my case (I got one somewhere else, if you understand what I'm saying). Would a bad boot.efi give me this problem?