Comment 0 for bug 1731241

[Impact]

 * grub exit on arm64-efi causes exception

[Test Case]

 * Using grub cmdline and exit shall return to UEFI

[Regression Potential]

 * Low regression risk due to
   - Only codes on exit with efi platform modified
   - patch cherry-picked from upstream and already in grub2 since zesty

[Other Info]

 * Patch on upstream

commit c945ca75c3b2b900040b905323b1226cb60a1166
Author: Mark Salter <email address hidden>
Date: Fri Aug 15 12:22:43 2014 -0400

    Fix exit to EFI firmware

    The current code for EFI grub_exit() calls grub_efi_fini() before
    returning to firmware. In the case of ARM, this leaves a timer
    event running which could lead to a firmware crash. This patch
    changes this so that grub_machine_fini() is called with a NORETURN
    flag. This allows machine-specific shutdown to happen as well
    as the shutdown done by grub_efi_fini().

    Signed-off-by: Mark Salter <email address hidden>