Some older computers only support the 32 bit EFI boot. One of them is the MacBook 2007. Although it can run a 64 bit OS, it only supports 32 bit EFI boot partitions.
If you want to install Ubuntu on a MacBook 2007, you can not just use the USB installer that comes with it.
To make it work:
- Flash the Ubuntu USB installer on a USB. msdos partition table seemed to work fine.
- Copy content of this repository into that installer USB
- Don't install Ubuntu but first try it on the USB so we can install an additional package missing.
- Run the following commands to install grub 32 bit package so that the installation will be succesful at the end.
sudo apt-get update
sudo apt-get install grub-efi-ia32
- Now install Ubuntu and it will work.
Well, it did for me :)