Re: Grub EFI fallback - patches for review
one option that doesn't seem to have been considered would be to create
a separate package (let's call it UEFIx) that installs an UEFI binary to
EFI/boot/bootx64.efi. That binary could then do what the UEFI BIOS
should've done (i.e. look at the EFI vars for bootorder, bootnext, etc
and then go on to load the right bootloader).
That way you'll have a solution that'll work across the different
bootloaders (grub-efi, gummiboot, etc), requires no changes to existing
bootloaders and which will only have an effect if explicitly installed
(adding d-i rescue code to optionally install the package should be
pretty straightforward as well). It also means that efibootmgr will work
as expected on both buggy and non-buggy machines.
I realize you're alredy pretty well ahead on a different solution and
that it's late in the Jessie game, but I thought I should at least throw
this idea into the ring (it's basically what Matthew originally
suggested in http://mjg59.dreamwidth.org/4125.html).