Building the toolchain - the hard way (Apple arm64 m1 Macs, gcc 11.3.0)

[jvasileff]

The script below compiles a toolchain with all the newest packs with gcc version 11.3.0, bintools version 2.39, and avr-libc version 2.1.0. It works on macOS and Linux for both x86_64 and arm64.

The main advantage vs. the toolchain that ships with the core is to have better performance on M1 Macs, which normally have to use the x86_64 toolchain. The performance of the arm64 version is at least double that of the x86_64 version on M1 Macs.

To use with megaTinyCore in the Arduino IDE on macOS, after compiling, delete the existing toolchain from ~/Library/Arduino15/packages/DxCore/tools/7.3.0-atmel3.6.1-azduino*, and copy the newly compiled toolchain to the same location (same directory name). Note that the old toolchain really does have to be deleted (or at least moved to some other directory), as the Arduino IDE has a stubborn habit of finding the old version, even when it has been renamed in some ways.

#!/bin/bash

# For Linux:
#   sudo apt update
#   sudo apt install -y build-essential texinfo automake
#
# For macOS:
#   install xcode & xcode commandline tools

set -eu
shopt -s expand_aliases

BUILD_DIR="$(pwd)"
INSTALL_DIR="${BUILD_DIR}"/avr-toolchain
GCC_VERSION=11.3.0
BINTOOLS_VERSION=2.39
MAKE_JOBS=10

PACKS=(
    Atmel.ATtiny_DFP.2.0.368.atpack
    Atmel.AVR-Ex_DFP.2.2.56.atpack
    Atmel.ATmega_DFP.2.0.401.atpack
    Atmel.AVR-Dx_DFP.2.1.146.atpack
)

#PACKS=(
#    Atmel.ATtiny_DFP.1.10.348.atpack
#    Atmel.AVR-Ex_DFP.1.0.38.atpack
#    Atmel.ATmega_DFP.1.7.374.atpack
#    Atmel.AVR-Dx_DFP.1.10.114.atpack
#)

mkdir $INSTALL_DIR
export PATH="${INSTALL_DIR}"/bin:$PATH

if [ -z "$MAKE_JOBS" ]; then
    MAKE_JOBS="1"
fi

heading_and_restore() {
    >&2 echo "----------------------------------------"
    >&2 echo "$*"
    >&2 echo "----------------------------------------"
    case "$save_flags" in
     (*x*)  set -x
    esac
}
alias heading='{ save_flags="$-"; set +x;} 2> /dev/null; heading_and_restore'

set -x

############################################################
heading "Download Sources"
############################################################
if [[ ! -e "avr-libc-2.1.0.tar.bz2" ]]; then
    wget 'https://mirrors.sarata.com/non-gnu/avr-libc/avr-libc-2.1.0.tar.bz2'
fi
if [[ ! -e "binutils-${BINTOOLS_VERSION}.tar.gz" ]]; then
    wget "https://ftp.gnu.org/gnu/binutils/binutils-${BINTOOLS_VERSION}.tar.gz"
fi
if [[ ! -e "gcc-${GCC_VERSION}.tar.xz" ]]; then
    wget "http://mirrors.concertpass.com/gcc/releases/gcc-${GCC_VERSION}/gcc-${GCC_VERSION}.tar.xz"
fi
if [[ ! -e "00-binutils-data_region_length.patch" ]]; then
    wget 'https://raw.githubusercontent.com/arduino/toolchain-avr/master/binutils-patches/00-binutils-data_region_length.patch'
fi
if [[ ! -e "gcc-11-arm-darwin.patch" ]]; then
    wget 'https://gist.githubusercontent.com/DavidEGrayson/88bceb3f4e62f45725ecbb9248366300/raw/c1f515475aff1e1e3985569d9b715edb0f317648/gcc-11-arm-darwin.patch'
fi
if [[ ! -e "config.guess" ]]; then
    wget "http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=HEAD" -O "./config.guess"
fi
if [[ ! -e "config.sub" ]]; then
    wget "http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=HEAD" -O "./config.sub"
fi

#wget 'http://packs.download.atmel.com/Atmel.ATtiny_DFP.2.0.368.atpack'
for pack in ${PACKS[@]}; do
    if [[ ! -e ${pack} ]]; then
        wget "http://packs.download.atmel.com/$pack"
    fi
done

############################################################
heading "Build and install binutils"
############################################################
tar xf binutils-${BINTOOLS_VERSION}.tar.gz
cd binutils-${BINTOOLS_VERSION}
patch -p1 < ../00-binutils-data_region_length.patch
./configure --prefix="${INSTALL_DIR}" --program-prefix=avr- --target=avr --disable-nls
make -j ${MAKE_JOBS}
make install
cd ..

############################################################
heading "Build and install gcc"
############################################################
tar xf gcc-${GCC_VERSION}.tar.xz
cd gcc-${GCC_VERSION}
if [ $(uname) = "Darwin" -a $(arch) = "arm64" ] ; then
    patch -p1 < ../gcc-11-arm-darwin.patch
fi
./contrib/download_prerequisites
cd ..
mkdir gcc-build
cd gcc-build
../gcc-${GCC_VERSION}/configure --prefix="${INSTALL_DIR}" --program-prefix=avr- --target=avr \
    --enable-languages=c,c++ --with-gnu-as --with-gnu-ld --disable-nls \
    --with-zstd=no \
    --enable-fixed-point \
    --disable-libssp \
    --disable-libada \
    --disable-shared \
    --with-avrlibc=yes \
    --with-dwarf2 \
    --disable-doc
make -j ${MAKE_JOBS}
make install
cd ..

############################################################
heading "Build and install avr-libc"
############################################################
if [ $(uname) = "Darwin" -a $(arch) = "arm64" ] ; then
    # workaround for arm mac
    export ac_cv_build=aarch64-apple-darwin
fi
tar xf avr-libc-2.1.0.tar.bz2
cd avr-libc-2.1.0
rm -f config.guess && cp -a ../config.guess .
rm -f config.sub && cp -a ../config.sub .
./bootstrap
./configure --prefix="${INSTALL_DIR}" --host=avr
make -j ${MAKE_JOBS}
make install
cd ..

############################################################
heading "Install atpacks"
############################################################
for packFile in ${PACKS[@]}; do
    echo "Installing ${packFile}"
    mkdir pack
    cd pack
    unzip -q ../${packFile}
    mv gcc/dev/*/device-specs/* "${INSTALL_DIR}"/lib/gcc/avr/${GCC_VERSION}/device-specs
    rmdir gcc/dev/*/device-specs
    cp -a gcc/dev/*/* "${INSTALL_DIR}"/avr/lib
    cp -a include/avr/* "${INSTALL_DIR}"/avr/include/avr/
    cd ..
    rm -rf pack
done

############################################################
heading "Done."
############################################################

[ObviousInRetrospect]

Very cool. I was thinking about trying to do a native build.

@SpenceKonde any opinion on GCC 11.3 vs 7.3? Any thoughts on how many hidden bugs switching is likely to uncover?