Part 1 - A Freestanding Rust Binary

Rust Analyzer and no_std

Starting this guide everything appears to be the working as intended with the guide. So far the only thing worth noting is that the Rust Analyzer is throwing errors regarding the use of the custom panic implementation as it still refers to the standard library despite the use of #![no_std].

Looking online there does appear to be some possible fixes and I may apply them if none of what is applied in future tutorials fixes it.

Nix issues with a different build targets

For my developer environment I use nix-direnv with a flake.nix which will install and setup any special packages as well as the Rust version I want.

Previously I was using the nightly version of Rust in order to use no_std however I couldn’t install extra targets though the flake.nix directly. Luckily the flake was already setup to install Rust according to a supplied rust-toolchain.toml file.

So I created the following rust-toolchain.toml file and committed it to git so Nix could properly detect it.

[toolchain]
channel = "nightly-2024-12-20"
components = ["rust-src", "rustfmt", "clippy"]
targets = ["thumbv7em-none-eabihf"]
profile = "default"  

When that was complete direnv reloaded and I was able to cross compile the existing example code.