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Hedy
Hedy

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How to use Cargo to cross compile Rust programs for Raspberry Pi?

#raspberrypi #cargo #rust

Here’s a practical, no-drama way to cross-compile Rust for Raspberry Pi with Cargo. Pick ONE of the three methods below; Method A is the simplest.

A) Easiest: cross (Docker-based)

# 1) Install cargo install cross rustup target add aarch64-unknown-linux-gnu # 64-bit Pi OS rustup target add armv7-unknown-linux-gnueabihf # 32-bit Pi 2/3/4 OS rustup target add arm-unknown-linux-gnueabihf # ARMv6 (Pi Zero/1) # 2) Build cross build --target aarch64-unknown-linux-gnu --release # or: cross build --target armv7-unknown-linux-gnueabihf --release # or: cross build --target arm-unknown-linux-gnueabihf --release # 3) Copy & run on the Pi scp target/<target>/release/yourapp pi@raspberrypi.local:/home/pi/ ssh pi@raspberrypi.local ./yourapp
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cross bundles the right GCC/linkers in Docker images, so you avoid toolchain setup pain. Great if your project pulls C libraries.

B) Native toolchains + Cargo (no Docker)

  1. Install cross GCC/linker on your dev machine

Ubuntu/Debian:

sudo apt-get update sudo apt-get install gcc-aarch64-linux-gnu gcc-arm-linux-gnueabihf
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macOS (Homebrew):

brew tap messense/macos-cross-toolchains brew install aarch64-linux-gnu-gcc arm-linux-gnueabihf-gcc
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  1. Add Rust targets 
rustup target add aarch64-unknown-linux-gnu rustup target add armv7-unknown-linux-gnueabihf rustup target add arm-unknown-linux-gnueabihf
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  1. Tell Cargo which linker to use (.cargo/config.toml at workspace root) 
[target.aarch64-unknown-linux-gnu] linker = "aarch64-linux-gnu-gcc" [target.armv7-unknown-linux-gnueabihf] linker = "arm-linux-gnueabihf-gcc" [target.arm-unknown-linux-gnueabihf] linker = "arm-linux-gnueabihf-gcc" # (Pi Zero/1 may need: rustflags = ["-C", "target-cpu=arm1176jzf-s"])
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  1. Build 
cargo build --target=aarch64-unknown-linux-gnu --release
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C) “It just works” linker: cargo-zigbuild

If you can install Zig:

cargo install cargo-zigbuild rustup target add aarch64-unknown-linux-gnu cargo zigbuild --target aarch64-unknown-linux-gnu --release
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Zig handles cross-linking without extra GCC toolchains.

Pick the correct target

The target depends on the OS architecture, not just the board. uname -m on the Pi: aarch64 → 64-bit, armv7l/armv6l → 32-bit.

Dealing with native C deps (OpenSSL, SDL, etc.)

  • On the Pi, install dev packages (sudo apt-get install libssl-dev, etc.).
  • When cross-compiling without cross/zigbuild, you may need: 
export PKG_CONFIG_ALLOW_CROSS=1 export PKG_CONFIG_LIBDIR=/usr/<triple>/lib/pkgconfig export PKG_CONFIG_SYSROOT_DIR=/
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  • If it’s painful, build those crates on the Pi once, or switch to Method A/C.

Sanity checks

file target/aarch64-unknown-linux-gnu/release/yourapp # Expect: ELF 64-bit LSB executable, ARM aarch64, ...
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