I'm trying to install Ubuntu 12.10 on my MacBook Pro (8,2). I installed it successfully a few weeks ago, but then discovered I did it using BIOS boot, which is how I've always done it, and that makes it so that my laptop will always use the discrete ATI graphics card and never the Intel integrated graphics. I noticed while using the laptop in Ubuntu that battery life was much worse than in Mac OS X, and the case seemed to be warmer than normal.
So I'm trying to reinstall to boot using UEFI. This (https://help.ubuntu.com/community/UEFI) seems to be the most "official" guide to doing it, but I've run into a few questions this doesn't answer. Since I want to dual-boot OS X, I have to do the manual partition option. The problem is that I have to create an EFI partition that is at the start of the disk, but one is already there. I assume that's what Mac OS X uses. Should I select that partition (/dev/hda1) to install the boot loader? Will it erase whatever OS X boot information is there?
To try to answer this question myself, I did some googling and came across other instructions which say I should choose the MBR (/dev/hda) to install the bootloader. Will that know to do EFI and not BIOS? Will it keep OS X bootable?