rust armv6 cross tools for ARMv6Z-based BCM2835

README.md

Run install_rust_armv6_target.sh

Rust is automatically installed with https://rustup.rs

sh ./install_rust_armv6_target.sh

Compile target from project directory

cd project_dir
cargo build --release --target=arm-unknown-linux-gnueabihf

Verify target is right arch

readelf --arch-specific target/arm-unknown-linux-gnueabihf/release/my_project

Alternative Toolchain

The raspberrypi/tools repository is out of date. The recommendation to install gcc-arm-linux-gnueabihf from the distributions apt repository would be fine for armv7.

For rpi0/1 the raspberrypi/tools repository mentions that it should be ./configured with --with-arch=armv6 --with-float=hard --with-fpu=vfp.

There are several options available, already compiled, through sourceforge, however they appear to have been abandoned. https://sourceforge.net/projects/raspberry-pi-cross-compilers/files/

see: https://github.com/abhiTronix/raspberry-pi-cross-compilers/wiki/Cross-Compiler:-Installation-Instructions

and also see: https://github.com/abhiTronix/raspberry-pi-cross-compilers for furhter details for using gcc-6 to gcc-10 or compiling the tool chain manually.

Another toolchain repository

GCC8/GCC9 https://github.com/Pro/raspi-toolchain

build_target.sh

# Run this to build for 'arm-unknown-linux-gnueabihf'
cargo build --release --target=arm-unknown-linux-gnueabihf

cargo_config

# for reference
[target.arm-unknown-linux-gnueabihf]
#linker = "arm-linux-gnueabihf-gcc"
linker = "/root/cross-pi-gcc-10.3.0-0/bin/arm-linux-gnueabihf-gcc-10.3.0"

# these will never work if the tools aren't configured and built for these options
# but i didn't know how to pass options to the cross-tools, this does that.
#[build]
#rustflags = ["-C", "link-args=-march=armv6 -mfpu=vfp"]

install_rust_armv6_target.sh

#! /bin/bash

set -e

BUILDDIR="${HOME}/build-rpi"
mkdir -p "${BUILDDIR}"
test -d "${BUILDDIR}/tools" || git -C "${BUILDDIR}" clone --depth=1 https://github.com/raspberrypi/tools.git
test -d "${BUILDDIR}/ripgrep" || git -C "${BUILDDIR}" clone --depth=1 --branch=0.8.1 https://github.com/BurntSushi/ripgrep.git

sudo apt update && sudo apt install -y gcc

PATH="${HOME}/.cargo/bin:${PATH}"
rustc --version || curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain="stable"

rustup target add arm-unknown-linux-gnueabihf

cat <<EOF > "${HOME}"/.cargo/config
[target.arm-unknown-linux-gnueabihf]
linker = "${HOME}/build-rpi/tools/arm-bcm2708/arm-linux-gnueabihf/bin/arm-linux-gnueabihf-gcc"
EOF

cd "${BUILDDIR}/ripgrep"
cargo build --release --target=arm-unknown-linux-gnueabihf
cd -

raspberry-pi_armv6_hardware.txt

ARMv6Z (32-bit):
  - Raspberry Pi 1 Model A
  - Raspberry Pi 1 Model A+
  - Raspberry Pi 1 Model B
  - Raspberry Pi 1 Model B+
  - Compute Module 1
  - Raspberry Pi Zero PCB v1.2
  - Raspberry Pi Zero PCB v1.3
  - Raspberry Pi Zero W

via: https://en.wikipedia.org/wiki/Raspberry_Pi#Specifications

verify_elf.sh

# verify arm6 armhf binary
readelf --arch-specific '<target/arm-unknown-linux-gnueabihf/release/my_project>'