We need basic support for UEFI - many newer servers don't support
BIOS compatibility mode anymore.
However, this patch only implements non-atomic because UEFI is FAT, and
we can't do the previous design for OSTree of atomic swap of
/boot/loader.
The Fedora/RHEL UEFI layout has the kernels on a "real" /boot
partition, and /boot/efi/EFI/$vendor just holds the grub2 UEFI binary
and grub.cfg.
Following this, /boot/loader is still on the OS boot partition, and we
still atomically swap it. This potentially paves the way to atomic
upgrades in the future.
https://bugzilla.gnome.org/show_bug.cgi?id=724246
Let's be a bit more conservative here and actually fdatasync() the
configurations we're generating.
I'm seeing an issue at the moment where syslinux isn't finding the
config sometimes, and while I don't think this is the issue, let's try
it.
There was an attempted optimization to only write if changed, but this
is broken - we always write the bootloader config into a new
directory.
In theory we should only be writing if it changed, but let's not do a
broken optimization.
Matthew Barnes
Colin Walters