[oddmiral]

Can this UEFI firmware be ported to other ARM devices, e.g. phones, tablets, books?

[ChickeNES]

Yes, it's just a port of the EDK2 UEFI reference firmware

[baobun]

Have you checked out uboot?

https://u-boot.org/

[franga2000]

Doesn't everything under the sun boot with uboot? Uboot is usually what people want to replace when they say "why can't this just run UEFI?"