A simple solution for the lack of a C standard library:

https://gitlab.com/bztsrc/posix-uefi

Features:

- works on POSIX systems, with native tools (no special build env needed)

- provides a (limited) POSIX interface for your UEFI app

- transparently converts UTF-8 and UCS-16 strings between your app and the firmware

- unlike GNU-EFI, no "uefi_call_wrapper" trickery needed

- has a tool to create a bootable disk image (with GPT, ESP)

- example codes from a "Hello World" to booting an ELF executable

- 100% AI-free