Rust Language Support

Rust is a modern systems programming language designed to provide memory safety, concurrency, and performance without sacrificing low-level control. It achieves this through a unique ownership model that eliminates common bugs like null pointer dereferencing and data races at compile time.

Rust’s emphasis on safety and correctness makes it particularly well-suited for embedded systems and environments where reliability is critical. Additionally, Rust offers powerful abstractions without a runtime or garbage collector, allowing developers to write both high-level code and low-level hardware interactions with confidence and efficiency.

These attributes make Rust a strong choice for projects on Zephyr, where resource constraints and system stability are paramount.

Enabling Rust Support

In order to enable Rust support in a Zephyr application, a few things need to be done:

  1. As Rust is currently an optional module, the module needs to be enabled. The easiest way to do this is with west:

    west config manifest.project-filter +zephyr-lang-rust
west update

    This should cause the Rust language support to be placed in modules/lang/rust in your Zephyr workspace.

  2. Enable Rust support, via CONFIG_RUST in the prj.conf. The easiest way to do this (as well as the CMake setup from the next step) is to start with one of the samples in modules/lang/rust/samples .

  3. Configure the application’s CMakeLists.txt file to support CMake. Again this is easiest to copy from a sample, but this will look something like:

    cmake_minimum_required(VERSION 3.20.0)

find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})

project(my_app)
rust_cargo_application()

  4. Create a Cargo.toml that describes how to build the Rust application. From the Hello World sample:

    [package]
# This must be rustapp for now.
name = "rustapp"
version = "0.1.0"
edition = "2021"
description = "The description of my app"
license = "Apache-2.0 or MIT"

[lib]
crate-type = ["staticlib"]

[dependencies]
zephyr = "0.1.0"
log = "0.4.22"

    The only required dependency is zephyr which provides the zephyr crate that is used to interface with Zephyr.

  5. Build as you would any other Zephyr application. Only a few targets currently support Rust (these can be seen in the modules/lang/rust/etc/platforms.txt file).

API Documentation

The API Documentation for the latest version in the module is kept on gh-pages.

This documentation is generated for a general target, with all features enabled. Once you have an application that is buildable, you can generate documentation specifically for your target:

west build -t rustdoc

...

Generated /my/path/app/zephyr/build/doc/rust/target/riscv32i-unknown-none-elf/doc/rustapp/index.html

The path printed at the end can be opened in a browser. This top level docs will be for your application itself. Look for the ‘zephyr’ crate on the left side bar, and this will take you to the docs for Zephyr. This page will also generate local docs for any dependencies used by your application, directly or indirectly.