I didn't see any mention of UEFI in my first read through about the Pi 5. Did I just miss it?
I would like to have a quiet and reasonably performant ARM aarch64 box at this price point, but only if it supports UEFI without needing to resort to silly EFI system partition tricks (which the Pi 4 required, last I knew).
The RPi4 has had a functional port of TianoCore for a while now, which is likely what they were referring to. You can use e.g. generic aarch64 UEFI Fedora images out of the box with it.
RasPi 4 requires some special files in the EFI system partition and a special non-stock EEPROM, at least for the older RasPi 4 boards, maybe the newer stock come with the UEFI-enabled EEPROM image? Regardless, in my experience with other EFI-enabled boards, I've never had to put the actual EFI into the EFI system partition, the EFI itself lives in a SPI flash usually so that you can boot "from" EFI with no "disks" attached.
Definitely the RasPi 4 having the ability to run UEFI, even in this way, is good. But what I'm looking for specifically is having UEFI just like every other UEFI-enabled PC and server does it, where I don't need a disk to boot to UEFI.
One of the differences in the Raspberry Pi 5 is the bootloader is in EEPROM. It has 2MiBytes which they doubt would be enough to fit a UEFI implementation. So it sounds to me like there isn’t much chance of UEFI this time.
2MiB could be enough space for an EFI implementation, but some features definitely would need to be disabled and it would definitely depend on how big the code for interfacing to the specific hardware on the board actually is. 4MiB is often big enough to have a functional EFI implementation, so 2MiB doesn't sound crazy to me, but I haven't tried.
I would like to have a quiet and reasonably performant ARM aarch64 box at this price point, but only if it supports UEFI without needing to resort to silly EFI system partition tricks (which the Pi 4 required, last I knew).