Comment # 10 on bug 1172114 from Gary Ching-Pang Lin

(In reply to Dominik Heidler from comment #8)
> Yes, /sys/firmware/efi is a directory with some files and subfolders in it
> on my Raspberry Pi 3B+.

Is there any like Boot0000-8be4df61-93ca-11d2-aa0d-00e098032b8c in
/sys/firmware/efi/efivars/ or /sys/firmware/efi/vars/? If u-boot did emulate
some UEFI variables, then we need to find another way to detect the emulated
UEFI environment...