I'm trying to install elementaryOS 4.1 on a Mac Mini, which from what I've read has a 64bit EFI, as well as 64bit CPU. When I hold down C to boot from disc, I get to a black screen with a prompt for CD ROM boot type, either 1 or 2. (1 is apparently to boot from disc and 2 from a HDD) The problem is the keyboard stops working at this point, so I can't select anything. I've tried using different keyboards, all wired including the stock USB apple keyboard.
I managed to install a modified version, it turns out that some macs even with 64bit EFI's can't boot 64bit operating systems. I found a version of elementaryOS 4.0 and It installed OK and booted fine, but its a slide show to use. The mouse pointer is fast and responsive, but in the OS everything I do is very delayed. I found a bunch of modified linux distros on this blog site https://mattgadient.com/2016/07/11/linux-dvd-images-and-how-to-for-32-bit-efi-macs-late-2006-models/
