RFE: Support for systemd-boot

[pm4rcin]

Hi, from my understanding since F39 users will be able to install systemd-boot cleanly even on Fedora-iot which raises the question if greenboot is going to work with it or will have to be disabled on such installs?

[say-paul]

Greenboot currently depends on grub variable, so It wont work for systemd-boot. I am not sure even ostree supports that too, Need some level of more investigation.

[LorbusChris]

That's indeed not supported yet by OSTree, see ostreedev/ostree#1719
Once that's unblocked, it'll also require some additional support in greenboot itself, as sd-boot uses a different (better) mechanism for boot counting (see: https://uapi-group.org/specifications/specs/boot_loader_specification/#boot-counting)

[cgwalters]

It makes sense, but honestly I think android-boot integration is more important (in progress for ostree). (And after that, supporting zipl)