GitHub Action Demo for Cross-Compiling for Raspberry Pi (ARM64)

🚀 ARM64 is now officially supported by GitHub Actions! 🚀

You shouldn't need to cross-compile for ARM64 now there's official support.

Introduction

This repo acts as a demo for how a GitHub Action can be used to cross-compile for an ARM64 Raspberry Pi running Raspberry Pi OS (as of 08 August 2023).

The Problem

Cross-compiling on some systems may result in the libc version used at link-time not being compatible with the run-time version, and you'll get an error similar to:

# Try and run a binary cross built elsewhere...
pi@raspberrypi:~ $ ./hello
./hello: /lib/aarch64-linux-gnu/libc.so.6: version `GLIBC_2.34' not found (required by ./hello)

And you can see why this is a problem:

# View which GLIBC versions it was linked against...
pi@raspberrypi:~ $ objdump -T hello | grep -Po 'GLIBC_[0-9.]+' | sort | uniq
GLIBC_2.17
GLIBC_2.34

# View which GLIBC versions are available locally...
pi@raspberrypi:~ $ objdump -T /lib/aarch64-linux-gnu/libc.so.6 | grep -Po 'GLIBC_[0-9.]+' | sort | uniq
GLIBC_2.17
GLIBC_2.18
GLIBC_2.22
GLIBC_2.23
GLIBC_2.24
GLIBC_2.25
GLIBC_2.26
GLIBC_2.27
GLIBC_2.28
GLIBC_2.29
GLIBC_2.30

A Solution

Raspberry Pi OS is based on Debian 11, so a solution is to cross compile in a Debian environment, such as a debian:11 container running on a GitHub Action. No need to download mystery binaries/toolchains!

You can find the GitHub Action configuraton for this repo here in cross-compile.yml.

Usage

Simply copy the cross-compile.yml file into your own repo under .github/workflows and adjust the compile steps/cmake config for your own project.

Caveats

This repo will age, and I'm sure it'll become outdated! If you're from the future, using debian:11 may be too old. Check which distribution your target version of Raspberry Pi OS is based on and adjust accordingly.