Thanks for the responses.
My device is a Macbook 2,1, and the issue I have is getting the Apple EFI to
detect any GNU/Linux USB drive; this includes those with an AMD64+Mac tag.
The only one that will work is a Clonezilla Live that I initially used to
take a backup of the existing disk (just in case). Unfortunately I was
unable to flash Libreboot from there, due to an issue with a Kernel setting
(bit above my head on that one!).
What I haven't tried is creating the USB disk from within OS X, as described
in the Github Page by Bibanon. I will give this a try with the images I have
and report back.
