I need some help with EDK2 on HiKey (1). After updating my hikey_optee project (2) with the latest 96boards/edk2 (3), I can't boot anymore. Is Grub now required to boot Linux? It seems that boot menu entries are hardcoded in (4), or am I missing something?. I could not really tell by reviewing the commit logs. Well in any case I'm getting the following menu:

 Fail to start BootNext.
 The default boot selection will start in   1 seconds
 [1] fastboot
 [2] grub on eMMC
 [3] grub on SD
 [4] Shell
 [5] Boot Manager

Entries 1-3 seem to do nothing, and just return to the same menu. Prior to this, EDK2 would boot Linux immediately as en EFI application, thanks to some entries in HiKey.dsc (5), which now seems to be ignored (are they really? similar entries are still present in 96boards/hikey which tends to indicate they're not obsolete).

What should I do to boot my kernel? I'd rather avoid adding Grub to the boot sequence, which is already complex enough IMHO, but I can of course do that if it is the recommended architecture. Now, if I could simply adjust my HiKey.dsc, that would be great...

(1) https://github.com/96boards/edk2
(2) https://github.com/linaro-swg/hikey_optee
(3) https://github.com/96boards/edk2/commits/4984b34
(4) https://github.com/96boards/edk2/blob/de234273/HisiPkg/HiKeyPkg/Drivers/HiKeyDxe/InstallBootMenu.c
(5) https://github.com/linaro-swg/edk2/blob/1690ce6/HisiPkg/HiKeyPkg/HiKey.dsc#L142