Comment by wtallis
6 days ago
As I recall, the PPC machines (like the Power Mac G5) never had EFI of any kind, and the early Intel Macs (including the Mac Pro) all had 32-but EFI even after the processors went 64-bit. I don't recall any of those Macs ever being switched from 32-bit EFI to 64-bit (U)EFI with a firmware update, or vice versa. It was a bit of a pain point because Linux was not initially ready to run a 64-bit kernel on top of 32-bit EFI, but that got resolved on the Linux side and I don't recall anything about Apple's firmware updates making that harder.
I must be mixing up my details, but I did think it was one of the first gen cheese graters.
I did have it booting Linux before upstream officially supported it. I remember using patches from infradead
You may very well be correct, Maybe it wasn't EFI, however they absolutely did ship an update that broke my existing installs, until upstream linux shipped an update, so your memory aligns more than mine does.