I just learned about EFIDroid, “a multiboot solution for mobile devices”. It is not new, EFIDroid was announced Feburary 2014 on the Xiaomi.eu mailing lists:
“Opensource (multiboot) Bootloader: Efidroid (formerly Grub4android):
This is the successor of GRUB4Android – a project to bring multiboot to Android. Even though most people hate UEFI on computers(users because of secureboot and devs because it doesn’t change many problems of BIOS afaik), Intel’s implementation (“EDKII”) actually is quite good and perfectly fits our needs. Also, it still allows you to boot GRUB – just in case you wanna do that.”
It is a Google+-based community, with over a hundred members. There’s been a lot of recent Github activity for the project, including an interesting Linux kernel module.
https://github.com/efidroid
https://plus.google.com/communities/114053643671219382368
http://xiaomi.eu/community/threads/dev-opensource-multiboot-bootloader-efidroid-formerly-grub4android.23615/
https://plus.google.com/u/0/MichaelZimmermann
http://mzimmermann.info/
Firmware Security 