Having read mixed reports as to whether it could be done or not i decided to see if i could find a way to boot Backtrack from a USB stick on my macbook pro. I havnt been able to find any other reports from anyone who has been successfully able to do this (Macbooks are notoriously reluctant to boot anything other than OS X from USB). It has however, been done with a few different versions of linux, Ubuntu being one of them.

Having played around with a few different setups for a while, this is what has (almost) worked for me.

Firstly I installed rEFIt, to give me a little more control over my boot options. Having played around with a few different setups using rEFIt to boot, i gave up. But then i came across this -

hxxps://bugs.launchpad.net/ubuntu/+source/linux/+bug/202039

Which gave me some hope. I used the fat binary there and dropped it into ~/EFI/BOOT/BOOTIA32.EFI and ~/EFI/BOOT/BOOTX64.EFI

When restarting and holding alt, my mac see's the usb stick and gives me the option for either booting rEFIt or an EFI boot. When choosing EFI boot i can successfully boot from the usb stick into GRUB2. Which gave me a little more hope.

Now ive tried a few things from here, I was unsuccessful when using an unpacked BT4PF iso on the usb stick with the following in my grub.cfg:

Code:
# Timeout for menu
set timeout=0

# Set default boot entry as Entry 0
set default=0

menuentry "BackTrack 4" {
 linux /boot/vmlinuz BOOT=casper boot=casper nopersistent rw vga=0x317 --
 initrd /boot/initrd.gz
}
This *should* have done the job, but alas it doesnt. Im not sure why, so i tried the different approach of booting directly from the iso. The following is my modified grub.cfg:

Code:
# Timeout for menu
set timeout=0

# Set default boot entry as Entry 0
set default=0

menuentry "BackTrack 4" {
fakebios 
loopback loop /boot/iso/bt4-pre-final.iso
linux (loop)/boot/vmlinuz find_iso/filename=/boot/iso/bt4-pre-final.iso BOOT=casper boot=casper nopersistent rw vga=0x317--
initrd (loop)/boot/initrd.gz
}
I tried first without the call to fakebios, but this seemed to make my system hang when inserting certain modules (as i found documented here hxxp://lists.gnu.org/archive/html/grub-devel/2009-05/msg00161.html]grub2 and fat efi files on latest Apples)

When I use this setup as is however, Backtrack boots! Only however, to a root@bt# command prompt.

When using startx i get something along the lines of:

Starting.....

No displays found.....

Then aborting. ls reveals only one file named install.sh.

Im a little stuck here.

Anyone shed any light on this? Ive pretty much exhausted my knowledge at this point.

Thanks in advance.