On Wed, Jul 27, 2022, at 4:30 PM, Lennart Poettering wrote:
So, let's say you want to make sd-boot be able to access a legacy ext4 /boot/ fs. First, fix the GPT partition type of that /boot/ partition to be the XBOOTLDR one (so that sd-boot can recognize it; currently fedora for some reason marks it as "generic Linux partition"). Then take the ext4 uefi driver from the project above, sign it as you sign every EFI binary, and drop it into the /EFI/systemd/drivers/ directory on the ESP. This is all you need to do, as sd-boot looks into that dir, and automatically loads all drivers found there.
Works for single distro installation, sure. But the intent and promise of BLS is distro interoperability with a shared $BOOT among multiple distros.
If the additional barrier to adoption that Fedora imposes is that every distro needs to also include signed efifs ext4 in order to read $BOOT, I think it's too much.
But also we need verification and clarification on this "GRUB only" proscription by Microsoft of any other bootloader, mentioned earlier in this thread: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/...