https://github.com/pbatard/fasmg-efi

There’s some more Flat Assembler samples targetting UEFI:

fasmg-efi – A simple UEFI sample in fasmg x86_64 assembly

Some other Flat Assembler/UEFI stuff is here:

UEFI programming in Flat Assembler (FASM)

FASM is the Flat Assembler. There’s a new Github project with some FASM-based assembly hello-world samples for UEFI. UEFI’s EDK-II generall prefers C over assembly, and has some code to help replace the need for assembly: I have some notes on that somewhere, I was going to write a blog on that someday. And I thought that EDK-II prefers NASM as their assembler, so this FASM-based, Intel 32-bit assembly-based UEFI sample code is interesting. The x86asm.net article on UEFI programming also has examples of FASM-based UEFI programming.

https://github.com/eszkadev/UEFI-32bit-asm-examples

http://flatassembler.net/

http://x86asm.net/articles/uefi-programming-first-steps/