Download and build the wireguard kernel module and tools for EdgeOS. see https://github.com/Lochnair/vyatta-wireguard

vyatta_wireguard_build.sh

#!/bin/bash

WIREGUARD_TAG=0.0.20181218

THISDIR=$(readlink -f $(dirname $0))
SYSROOT=$THISDIR/sysroot
TARGET=mips64-octeon-linux-gnu
MUSL_CC=$SYSROOT/bin/musl-gcc

export PATH=$THISDIR/toolchain/bin:$PATH
export CROSS_COMPILE=${TARGET}-
export CC=${CROSS_COMPILE}gcc
export CFLAGS="-O2 -mabi=64"
export ARCH=mips
export PKG_CONFIG_PATH=$SYSROOT/lib/pkgconfig

msg() {
    echo -e "\033[1;36m+ $*\033[0m" >&2
}

run() {
    msg "$*"
    "$@"
}

download_sdk() {
    if [[ ! -d OCTEON-SDK ]]; then
        export GIT_LFS_SKIP_SMUDGE=1
        run git clone https://github.com/Cavium-Open-Source-Distributions/OCTEON-SDK/
        unset GIT_LFS_SKIP_SMUDGE
    else
        msg "OCTEON-SDK already cloned"
    fi
    if [[ ! -f OCTEON-SDK/OCTEON-SDK/tools/bin/$CC ]]; then
        pushd OCTEON-SDK
        run git lfs pull -I OCTEON-SDK-5.1.tbz
        run tar xf OCTEON-SDK-5.1.tbz
        popd
    else
        msg "Toolchain already extracted"
    fi
    if [[ ! -d toolchain ]]; then
        run ln -s OCTEON-SDK/OCTEON-SDK/tools toolchain
    fi
}

build_sdk() {
    :
}

download_kernel() {
    local gpl_url="https://dl.ubnt.com/firmwares/edgemax/v1.10.x/GPL.ER-e300.v1.10.8.5142457.tar.bz2"
    local gpl_archive="$(basename "$gpl_url")"
    local kernel_archive="kernel_5142457-g796b1bf.tgz"

    if [[ ! -f $gpl_archive ]]; then
        run wget "$gpl_url"
    else
        msg "GPL archive already downloaded"
    fi
    if [[ ! -f $kernel_archive ]]; then
        run tar xf $gpl_archive -O source/$kernel_archive >$kernel_archive
    else
        msg "kernel archive already extracted"
    fi
    run rm -rf kernel
    run tar xf $kernel_archive
}

build_kernel() {
    run make -C kernel scripts prepare
    run make -C kernel INSTALL_HDR_PATH=$SYSROOT headers_install
}

download_musl() {
    if [[ ! -d musl ]]; then
        run git clone git://git.musl-libc.org/musl
    else
        msg "musl was already cloned"
        run git -C musl fetch
    fi
    pushd musl
    run git reset --hard
    run git clean -dxfq
    run git checkout v1.1.20
    popd
}

build_musl() {
    pushd musl
    ./configure --host=x86_64 --target=$TARGET --prefix=$SYSROOT --enable-static --disable-shared
    run make
    run make install
    popd
}

download_libmnl() {
    if [[ ! -d libmnl ]]; then
        git clone git://git.netfilter.org/libmnl
    else
        msg "libmnl already cloned"
        run git -C libmnl fetch
    fi
    pushd libmnl
    run git reset --hard
    run git clean -dxfq
    run git checkout libmnl-1.0.4
    popd
}

build_libmnl() {
    pushd libmnl
    run ./autogen.sh
    run ./configure CC=$MUSL_CC --prefix=$SYSROOT --host=$TARGET --enable-static --disable-shared
    run make
    run make install
    popd
}

download_wireguard() {
    if [[ ! -d WireGuard ]]; then
        run git clone git://git.zx2c4.com/WireGuard
    else
        msg "WireGuard already cloned"
        run git -C WireGuard fetch
    fi
    pushd WireGuard
    run git reset --hard
    run git clean -dxfq
    run git checkout $WIREGUARD_TAG
    run sed -i 's/prandom_u32_max/\0_exclude_for_e300/' src/compat/compat.h
    popd
}

build_wireguard() {
    run make -C kernel M=$THISDIR/WireGuard/src modules
    run cp -f WireGuard/src/wireguard.ko .

    run make CC=$MUSL_CC -C WireGuard/src/tools
    run cp -f WireGuard/src/tools/wg .
    run ${CROSS_COMPILE}strip wg
}

set -e
if (( $# == 0 )); then
    set -- sdk kernel musl libmnl wireguard
fi
for x in "$@"; do
    case $x in
        build_*|download_*)
            eval $x
            ;;
        *)
            eval download_$x
            eval build_$x
            ;;
    esac
done