Re: Fedora 21 LiveUSB Won't boot on Macbook Pro 2,1
I think your best bet, which isn't easy, is to do a VM installation. If you get aggressive, within that VM you could build a 32-bit GRUB and from that a grub2-install will produce a 32-bit grubx32.efi which you can add to a live media USB in the same location as the grubx64.efi and I think it'll just figure out it needs to use the 32 bit version. There might be a trick getting it to find the grub.cfg, hopefully it just finds it. If not, you'll need to use a combination of ls to find the grub designation for the device and partition, and then set, set root, set prefix, and configfile to point to the grub.cfg on the install media to boot. And then post-install you'll have to replace the grub that's installed with the one you've built. Bit tedious, which is why it's easier to just use a VM.