Skip to content

Rust

Cross-Compiling Rust for Raspberry Pi

I just started a new embedded pet project on the Raspberry Pi, and I expect it'll be a pretty big one, so I've been thinking about the technology from the beginning. The overall goal is to create a glass-to-glass video pipeline example. Let's see how it's going. For now, I'm using a USB V4L2 camera while waiting for the native Pi modules to arrive, but it's enough to sketch the capture loop and start testing the build pipeline. The application itself is minimal—open /dev/video0, request YUYV at 1280x720, set up MMAP buffers, and iterate over frames—but the real challenge occurs when v4l triggers bindgen, and the build must cross-compile cleanly for aarch64. 

The language choice immediately becomes part of the equation right away. Go is my favorite and, usually, is not considered as an option by many embedded developers. But it's a good choice for small embedded utilities because its cross-compilation story is nearly effortless. Need an ARM binary? One command and you have it!

GOOS=linux GOARCH=arm64 go build

Bazel and Rust: A Perfect Match for Scalable Development

caption

Bazel never fails to impress, and its support for Rust demonstrates its versatility and commitment to modern development. Two distinct dependency management modes—Cargo—based and pure Bazel—allow developers to tailor workflows to their projects' needs. This adaptability is particularly valuable for integrating Rust applications into monorepos or scaling complex systems. I decided to explore how Bazel supports Rust, including managing dependencies, migrating from Cargo.toml to BUILD.bazel, and streamlining integration testing.

Harnessing Cargo-Based Dependency Management

Bazel’s ability to integrate with Cargo, Rust’s native package manager, is a standout feature. This approach preserves compatibility with the Rust ecosystem while allowing projects to benefit from Bazel’s powerful build features. By using rules_rust, a Bazel module can seamlessly import dependencies defined in Cargo.toml and Cargo.lock into its build graph.

Returning to Rust: A Journey Through Tooling, Performance

When I started tackling the Maelstrom challenges, my initial thought was to use C++. It’s a language I know inside out, and its performance is hard to beat. However, as I contemplated setting up the project, I realized I couldn’t justify fighting with the C++ pipeline for free. Crafting a proper CMake or Bazel configuration might be worthwhile for large-scale projects or when compensated, but for personal experiments? It’s an unnecessary headache.

Why Go is My Default Choice

For most non-performance critical scenarios, Go is my default, no-brainer choice. It has a clean build system, excellent tooling, and a developer experience that doesn’t make me dread the setup process. Go’s simplicity allows me (and any level team) to focus on solving the problem rather than wrestling with the environment. Yet, this time, I decided to take a different path.