I've been pulling my hair out trying to get a full Ubuntu installation running on my USB, and I think I just got it working for Windows (by disconnecting my hard drives during Live CD installation...).

However, the result isn't bootable on my Macbook Air. After more reading, it seems that it's a U/EFI problem which Ubuntu solved by creating an amd64+mac version of the installation.

I'm downloading that now, but I'm wondering: will this ONLY work for my Macbook, and stop working on the Windows computer?


  • 1
    @muru When the installation is done on Windows and doesn't boot on a Mac, then I assume the problem is related to the UEFI loader (bless?), not the ISO image, though the title is a bit misleading.
    – LiveWireBT
    Dec 12, 2014 at 13:01
  • @LiveWireBT Though the problem is with the loader, it is solved by using a different ISO. OP's question is whether the different ISO will work on their Windows-running laptop, which is easily answered by explaining the difference (which is what Rohith does in concise way).
    – muru
    Dec 12, 2014 at 13:07
  • @muru It seems to be absolutley correct that Macs can't boot multicatalog ISOs. The better workaround for that is to prepare a USB drive with a UEFI loader to loop mount and boot the ISO with UEFI instead of sticking with old technology. Also you have to assume that CSM is available on all computers, which is not the case (because it's planned to be phased out).
    – LiveWireBT
    Dec 12, 2014 at 14:57

1 Answer 1


The amd64+mac version should work on both the Mac and the PC.

The difference between the amd64 and the amd64+mac is that the amd64 version is 'multi-catalog', ie it can boot on either BIOS or UEFI systems whereas the amd64+mac version only support BIOS booting.

The problem is that Macs are not able to boot 'multi-catalog' disks. However, you can get your Windows machine to boot from it by selecting the Legacy/BIOS option instead of the UEFI option.

  • Understood completely :D beautiful answer sir!
    – Bilal Akil
    Dec 12, 2014 at 9:02
  • Wasn't the question more about the result? Shouldn't Macs be able to boot from an external drive once the EFI binary is in the right place and named properly so that the Mac firmware can find it? (The binary probably needs to be blessed wiki.archlinux.org/index.php/GRUB/…) unix.stackexchange.com/q/57964/49853 astrofloyd.wordpress.com/2014/01/14/…
    – LiveWireBT
    Dec 12, 2014 at 12:55
  • @LiveWireBT The question was whether the amd64+mac variant will boot on a Windows PC which has been answered in the first line. In order to EFI boot Ubuntu on a Mac, not only will the boot partition have to be blessed but must also be formatted as an HFS+ volume, instead of the default FAT partition that the Ubuntu installer creates, for the system to boot. Dec 12, 2014 at 17:07

Not the answer you're looking for? Browse other questions tagged or ask your own question.