[Guide] Mac OS X Lion: How To Boot A Linux Live System From An USB Drive & How To Update Any OCZ SSD

转自 http://tillmail.de/wordpress/436

Some Problems I Experienced

A Mac uses
EFI instead of BIOS to manage bootable devices. I experienced a decent lack of EFI support when I used Linux live systems. Everything crashed or froze or didn’t even show up in the boot menu. A common workaround
seems to be rEFIt but it isn’t compatible with OS X Lion and I don’t like to modify system tools. (Update: Things have changed, but I still don’t want to mess around, just to update my SSD)
There is no SSD firmware update tool by OCZ for OS X so you’re forced to use a Linux live system unless you want to make changes to your hard drive setup – like using Bootcamp.
I replaced my optical drive with a HDD to insert a SSD in the original HDD-Bay – a common modification – but obviously a Mac hates to boot from an external optical drive. As mentioned earlier boot processes crashed or froze.

My Solution How To Boot A Linux Live System

Okay, I found an EFI-loader that has been able to boot nearly every version of Ubuntu and is very easy to setup and it even doesn’t need
rEFIt.
I found it in a German Mac Forum and it comes with a very detailed description how to use it but this description didn’t work for me. Here’s what I did to boot Ubuntu 11.04 Desktop Edition 64 bit as a live system from an external USB Drive on a MacBook
Pro 13’3 early 2011 that was equipped with a 320GB HDD and a 120GB OCZ Agility 3 :

Get the ISO-2-USB EFI-Booter for Mac 0.01 beta and a recent version of Ubuntu Desktop Edition 64bit.
Format a USB drive to provide a single FAT32 partition featuring
MBR.
Create the following directories on your USB drive: /efi and /efi/boot
Copy the bootX64.efi from “ISO-2-USB EFI-Booter for Mac 0.01 beta” into
/efi/boot on your USB Drive.
Copy the Ubuntu image into /efi/boot/ on the USB Drive, too and rename it to “boot.iso”.
You should have 2 files on your USB drive now: bootX64.efi and
boot.iso - both in /efi/boot.
You’re ready to reboot: During the startup of your Mac hold Alt/Option. You should see “EFI Boot” which has a nice little USB Drive Symbol on it in the appearing boot menu. Boot from your USB Drive by clicking on the little arrow below
it.
Good Luck!
Ubuntu should be booting now…

Additional information

I didn’t test any 32bit systems. But in case you wish to do so I guess you ought use “bootIA32.efi” from ”ISO-2-USB EFI-Booter for Mac 0.01 beta”.
Your USB Drive should be able to carry 4 partitions in MBR, but I tried to evade any confusion.
This shouldn’t be restricted to Ubuntu, but I never tried another Distribution as I was veeeeery glad that at least one thing worked.
I don’t know where “ISO-2-USB EFI-Booter for Mac 0.01 beta” comes from… Maybe it is extracted from rEFIt oder even
elilo. Please keep me updated.
This whole “/efi/boot”-thing is pretty straight forward and seems to be part of EFI specifications but I can’t prove this.
I used a 2GB USB thumb drive a friend of mine forgot at my place. Nothing special.

Updating an OCZ SSD’s firmware

After you’ve booted into Ubuntu
just follow the official guide. Don’t forget to enable TRIM!