XFS is also not supported. But yes, your /boot can be fat32, but saying "nobody cares" is just needlessly dismissive, I can think of many reasons to care at least a little. Primary of which is lack of encryption and ability to mirror easily, another can be the possible corruption of /boot (FAT is not typically used for it's data consistency properties)
> Nobody really supports OPAL, even grub. The only reliable solution is using https://github.com/sedutil/sedutil to unlock the disk and then soft reboot into any normal bootloader.
I guess this is a fair statement, if you ignore that the "PBA" is actually using grub itself, but yes, the PBA is non-encrypted and usually lives as a separate partition, making it functionally equivalent between systemd-boot and grub2.
> You can do mdraid, you just have to stick the metadata at the end of the drive rather than the beginning. The utilities that set up your raid even warn you about this because this setup is so standard.
You can't boot to an mdraid device with systemd-boot, you can only have a separate (non mirrored or raid'd) partition on a drive, and point to that drive to boot.
Sorta kinda true in theory but not in practice. Yes systemd-boot isn't raid aware but if you configure mdraid to store its metadata at the end of the drive then you wind up with a, say, mirrored disk that to the firmware doesn't look like it's mirrored at all. And since the firmware just reads the partition it's safe and works.
So yes, you have to configure your firmware to look at both drives in a mirrored setup as a fallback but you can boot.
> but saying "nobody cares" is just needlessly dismissive
Fair, I'm more saying that having firmware that only supports a small set of simple filesystems is the usually the more normal situation, the fact that GRUB comes with all the drivers makes it the weird one.
You're screwed when the firmware decides to write to the ESP though.
It's hardware RAID or nothing, at least for the ESP for me!
* systemd-boot doesn't support those filesystems as the /boot partition, all of those things for your / are totally fine. For most people having your /boot partition be XFS vs FAT32 is firmly in the "who cares?" realm.
* Nobody really supports OPAL, even grub. The only reliable solution is using https://github.com/sedutil/sedutil to unlock the disk and then soft reboot into any normal bootloader.
* You can do mdraid, you just have to stick the metadata at the end of the drive rather than the beginning. The utilities that set up your raid even warn you about this because this setup is so standard.