UPDATED: March 24, 2009
I have been a long time Linux guy and have recently fallen victim to loving the MacBook Pro’s (and OS X as well). I still wanted to have a nice way to work in Linux on my MacBook Pro without some crazy repartioning/Boot Camp hack, so I tried putting Ubuntu on a USB stick and boot it with my MBP 3,2 only to find (even using rEFIt, that it didn’t work). So alot of reading later, it is general consensus that it is not going to work in any easy way on an MPB 3,2. So I got a new Aluminum MBP 5,2 recently and thought, why not give it another shot. I grabbed by Ubuntu 8.10 (created using debootstrap and some other customizations) and the latest rEFIt, 0.12) and to my surprise I got a GRUB boot screen and eventually a Gnome desktop. I was quite surprised and happy. Next step is to get rEFIt installed onto a USB hard disk and have it boot that external disk, so that I don’t need a rEFIt CD. I do not want to install rEFIt to my HD as the idea would be to have something portable for my work MacBook Pro, my wife’s MacBook Pro, my personal MacBook Pro and any other MacBook Pro (5th gen v. 2) that I came across.
It works! Can now boot Linux on an unmodified MacBook Pro (5,2) from a single USB stick (or external hard drive). I created a small 25MB partition as the first partition, formated it as Mac OS X Journaled and installed rEFIt to it, then followed that partition with a 100 MB boot partition, and then a root partition on a thumb drive (if using an external hard drive you could create swap as well, but I don’t do that on thumb drives so they don’t get worn out). Install linux normally (debootstrap is how I do it) onto the second and third partitions. Make sure Grub is installed to the MBR of the drive and points to the /boot partition as the second partition. Then take the USB drive to a MacBook Pro and insert it. Turn on the MBP and hold down the Alt/Option key until you see a boot menu offering Mac OS X or rEFIt. Choose rEFIt. After that you’ll be give a menu to choose OS X again or Linux. Here, choose Linux. Tada, now comes the Grub boot screen and then on into the Linux of your choice. Congrats and enjoy…