Polkadot Raspberry PI cross-compile build

cross-build.sh

#!/usr/bin/env bash

# Run this script from the directory with the Cargo project.

DOCKER_IMAGE="polkadot/rpi"

docker build -t $DOCKER_IMAGE .
docker run --rm -it \
	--env BINDGEN_EXTRA_CLANG_ARGS="--sysroot=/usr/arm-linux-gnueabihf -D__ARM_PCS_VFP -mfpu=vfp -mfloat-abi=hard" \
	--env CARGO_HOME=/home/rust/src/cargo_home \
	-v "$(pwd)":/home/rust/src polkadot/rpi \
	cargo +nightly build -Z features=itarget --target=armv7-unknown-linux-gnueabihf --release

Dockerfile

# Put this file in the root of substrate / polkadot directory and build the image using
# the following command
#
#     docker build -t <container id> .
#
# you can pick <container id> yourself. For example: `johndoe/rpi-cross`.
#

FROM rust:latest

RUN dpkg --add-architecture armhf && \
    apt-get update && apt-get upgrade -y && \
    apt-get install -y aptitude && \
    aptitude install -y \
        gcc-arm-linux-gnueabihf \
        g++-arm-linux-gnueabihf \
        pkg-config \
        cmake \
        libssl-dev \
        git \
        clang \
        libclang-dev \
        libssl-dev:armhf

RUN rustup install nightly
RUN rustup target add armv7-unknown-linux-gnueabihf --toolchain nightly
RUN rustup target add wasm32-unknown-unknown --toolchain nightly
RUN cargo +nightly install --git https://github.com/alexcrichton/wasm-gc --force

ENV CARGO_TARGET_ARMV7_UNKNOWN_LINUX_GNUEABIHF_LINKER arm-linux-gnueabihf-gcc
ENV PKG_CONFIG_ALLOW_CROSS 1
ENV PKG_CONFIG_PATH /usr/lib/arm-linux-gnueabihf/pkgconfig/

RUN useradd rust --user-group --create-home --shell /bin/bash --groups sudo
WORKDIR /home/rust/src