Comment 123 for bug 774089

@krysztof:
there's no 64+mac release for natty here: http://releases.ubuntu.com/natty/ (I know there are for oneric, but I'm not sure if we're talking about the same thing)

I dug up a lot of details about this bug, given its seriousness, and it seems to be threefold:

-a bug in the installer, that wrongly detects mac systems as suitable for grub-efi to be installed (due to mac specific quirks it seems the plan will be to stay on the safe side and rely on the old bios-compatibility for installing ubuntu on macs... I asked on irc and this is what I've been told by cjwatson)
-(maybe) a bug in efibootmgr (or its configuration in ubuntu)... given that it deletes some of the BootCommands from the efi ...also: I read somewhere about efibootmgr using elilo by default (and this would mismatch with grub-efi), but i'm not so sure about that anymore
-a bug in the kernel, that was fixed in these commits:
http://git.kernel.org/?p=linux/kernel/git/stable/linux-3.0.y.git;a=commit;h=202f9d0a41809e3424af5f61489b48b622824aed
http://git.kernel.org/?p=linux/kernel/git/stable/linux-3.0.y.git;a=commit;h=7cb00b72876ea2451eb79d468da0e8fb9134aa8a
http://git.kernel.org/?p=linux/kernel/git/stable/linux-3.0.y.git;a=commit;h=935a638241b0658b9749edd060f972575f9d4a78
http://git.kernel.org/?p=linux/kernel/git/stable/linux-3.0.y.git;a=commit;h=916f676f8dc016103f983c7ec54c18ecdbb6e349
 (I got this info by asking redhat's pjones)

These changes are in the linux kernel 3.0, and that's the one that is being used by oneric

I don't have the problem myself, but I have a friend who does... I asked him to try and he reported me that indeed in oneiric the problem doesn't seem to appear

I cannot confirm this first hand, though

also: the problem in the kernel has been fixed, but the bug in the installer is still there afaik

some other useful info about the fix:

-after blessing the firmware updater, the reboot will take several seconds to start it up, so it's normal if you have to wait a bit more
-my friend as a macbook pro 5,4 ... as said in this thread: the firmware update for version 5,3 is fine as well. but pay attention to the actual .scap you'll be using: inside the 5,3 .app, there's also the mbp55 firmware... if you'll apply that, your efi will get even more bricked!
-unfortunately that's exactly what happened, and this was impeding the boot every single time (unless the PRAM was resetted, but resetting the PRAM deletes any boot settings, like the one enabled by bless)... but it seems there's also another way to recover from this situation:
http://forums.macrumors.com/showthread.php?p=8414998&posted=1#post8414998
by burning a .dmg to a disk, it's possible to load it and flash the firmware even without using bless