Building esp32-wifi against Rust 1.50.0 using ESP-IDF 4.2

README.md

1. Grab the following:
   • https://github.com/kelnos/rust-xtensa (branch xtensa-update-12-02-2021) OR download https://files.spurint.org/rust/rust-1.50.0-nightly-xtensa.tar.bz2
   • https://github.com/kelnos/esp32-hal (branch rust-1.50)
   • https://github.com/kelnos/esp32-wifi (branch experiments)
2. If you've downloaded the Rust tarball, unpack to /opt/xtensa. If you are building from source, use the script provided in this gist (rust-xtensa-build) to build it.
3. Install form: cargo install form
4. Install svdtools (requires python 3.6 or above): pip3 install --upgrade --user svdtools
5. Install an old-ish version of svd2rust using: cargo install --git https://github.com/rust-embedded/svd2rust --rev 29129c0e4e261bf4c38057f7585e7ddfc05fafd0 -- svd2rust
6. Fetch version 4.2 of ESP-IDF (https://github.com/espressif/esp-idf/archive/v4.2.tar.gz), and unpack it somewhere. Set the IDF_PATH env var to its location (actually I don't think you need this unless you are regenerating the rust bindings in esp32-wifi).
7. Fetch the latest ESP32 toolchain/binutils (https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-guides/tools/idf-tools.html#xtensa-esp32-elf) and unpack in /opt/xtensa.
8. Grab the provided rust-xtensa script and source it into your shell session.
9. In the esp32 crate source, run make.
10. In the esp32-wifi checkout, create a file called rust-toolchain that just contains the word nightly, and run cargo xbuild --example test.

rust-xtensa

root=/opt/xtensa
rust=$root/rust

export RUST_BACKTRACE=full
export XARGO_RUST_SRC=$rust/lib/rustlib/src/rust/library
export RUST_SRC_PATH=$XARGO_RUST_SRC
export RUSTC=$rust/bin/rustc
export RUSTDOC=$rust/bin/rustdoc
export PATH=$rust/bin:$PATH:$root/xtensa-esp32-elf/bin

rust-xtensa-build

#!/bin/bash

set -e

prefix=/opt/xtensa/rust
channel=nightly
base_debug_args="--enable-debug --disable-optimize --disable-optimize-llvm --enable-llvm-release-debuginfo"
jobs=$(($(nproc)-2))
clean=true
build=true
install=true
hostmach=unknown
hostabi=gnu

checkarg() {
    [ "$2" ] || {
        echo "'$1' requires an argument" >&2
        exit 1
    }
}

while [ "$1" ]; do
    case "$1" in
        --prefix)
            checkarg "$1" "2"
            prefix=$2
            shift
            ;;
        --channel)
            checkarg "$1" "$2"
            channel=$2
            shift
            ;;
        --debug)
            extra_configure_args="$base_debug_args"
            ;;
        --debug-assert)
            extra_configure_args="$base_debug_args --enable-llvm-assertions --enable-debug-assertions"
            ;;
        --jobs|-j)
            checkarg "$1" "$2"
            jobs=$2
            shift
            ;;
        --host-mach)
            checkarg "$1" "$2"
            hostmach=$2
            shift
            ;;
        --host-abi)
            checkarg "$1" "$2"
            hostabi=$2
            shift
            ;;
        --no-clean)
            clean=false
            ;;
        --no-build)
            build=false
            ;;
        --no-install)
            install=false
            ;;
        *)
            echo "Unknown option '$1'" >&2
            exit 1
            ;;
    esac
    shift
done

hostarch=$(uname -m)-$hostmach-$(uname -s | tr '[A-Z]' '[a-z]')-$hostabi

if [ "$clean" = "true" ]; then
    git clean -xfd
fi

if [ "$build" = "true" ]; then
    ./configure \
        --prefix=$prefix \
        --release-channel=$channel \
        --experimental-targets=Xtensa \
        --disable-docs \
        --disable-compiler-docs \
        $extra_configure_args
    ./x.py build --stage 2 --jobs $jobs
fi

if [ "$install" = "true" ]; then
    rm -rf $prefix/* || true
    ./x.py install
    mkdir -p $prefix/lib/rustlib/src/rust
    cp -av Cargo.lock library $prefix/lib/rustlib/src/rust
    mkdir -p $prefix/lib/rustlib/$hostarch
    cp -av build/$hostarch/llvm/bin $prefix/lib/rustlib/$hostarch/
    cp -av build/$hostarch/stage2/lib/rustlib/$hostarch/ $prefix/lib/rustlib/$hostarch/
fi

TODO.md

• Figure out why the output of the latest rust2svd doesn't work with our esp32-hal