uefi-rs

> significantly reduce the amount of C code but I'm not sure you could eliminate it entirely Theseus is a research OS written in Rust that seems to include C purely to show how to support programs written in C (libc and a demo app). https://github.com/theseus-os/Theseus It contains some 1000+ lines of ASM for the early boot from BIOS, that look like they originate from https://os.phil-opp.com/minimal-rust-kernel/ -- I think UEFI boot would have been doable in pure Rust (https://github.com/rust-osdev/uefi-rs).

> I would say Rust would be the best fit, but I admit that it's not a perfect fit; sadly, we lack safe low-level languages. Rust is a safe low-level language. You can start writing your UEFI implementation in rust today [1], [2] > As for running without UEFI/BIOS: most ARM devices have an alternate bootloader UEFI/BIOS is not a bootloader, they initialize hardware and then pass on responsibility to a bootloader. Popular bootloaders are the Windows bootloader, grub, etc etc. 1: https://rust-osdev.github.io/uefi-rs/HEAD/ 2: https://github.com/rust-osdev/uefi-rs/tree/main/template

First off I don't recommend implementing the specification from scratch. It is big, and there are implementations already in various languages: for C you can use GNU-UEFI, for example, Rust has uefi-rs, and Zig has support in its standard library. These take care of the fiddly details of interacting with the UEFI firmware's services. There's tutorial type articles for these around: for C there's https://wiki.osdev.org/UEFI_App_Bare_Bones, for Rust there's this template https://github.com/rust-osdev/uefi-rs/tree/main/template and the crate's documentation. I don't think the role of firmware requires it to be minimal. It's to provide a consistent boot environment on different hardware, and to provide useful services to the program. Even BIOS-based machines have significant amounts of code that run before they jump to the boot sector, so whi