grub-lakitu: REDHAT: MASTER-SB: Rework even more of efi chainload so non-sb cases work right.

This ensures that if shim protocol is not loaded, or is loaded but shim
is disabled, we will fall back to a correct load method for the efi
chain loader.

Here's what I tested with this version:

results                             expected    actual
------------------------------------------------------------
sb + enabled + shim + fedora        success     success
sb + enabled + shim + win           success     success
sb + enabled + grub + fedora        fail        fail
sb + enabled + grub + win           fail        fail

sb + mokdisabled + shim + fedora    success     success
sb + mokdisabled + shim + win       success     success
sb + mokdisabled + grub + fedora    fail        fail
sb + mokdisabled + grub + win       fail        fail

sb disabled + shim + fedora         success     success*
sb disabled + shim + win            success     success*
sb disabled + grub + fedora         success     success
sb disabled + grub + win            success     success

nosb + shim + fedora                success     success*
nosb + shim + win                   success     success*
nosb + grub + fedora                success     success
nosb + grub + win                   success     success

* for some reason shim protocol is being installed in these cases, and I
  can't see why, but I think it may be this firmware build returning an
  erroneous value.  But this effectively falls back to the mokdisabled
  behavior, which works correctly, and the presence of the "grub" (i.e.
  no shim) tests effectively tests the desired behavior here.

Resolves: rhbz#1344512

Signed-off-by: Peter Jones <pjones@redhat.com>

(cherry picked from commit d92273bddee4025aaa54acf51dea6782b49b97db)
(from master-sb branch of https://github.com/rhboot/grub2)

BUG=b:69569602
TEST=TBD

Change-Id: Ie62db1625d57ca6f27e94c841d611da9ff1207c9
Reviewed-on: https://chromium-review.googlesource.com/945898
Reviewed-by: Edward Jee <edjee@google.com>
Commit-Queue: Edward Jee <edjee@google.com>
Tested-by: Edward Jee <edjee@google.com>
Trybot-Ready: Edward Jee <edjee@google.com>
6 files changed
tree: 379cc6910bc00fcad26db134276520cc66a1de87
  1. COMMIT-QUEUE.ini
  2. README
  3. grub-lakitu/