Enabling WireGuard on a Raspberry Pi with 64-bit kernel

wg_64bit_kernel.sh

sudo apt install -y zip git wget
mkdir ubuntu; cd ubuntu

function post_chroot {
cat <<EOT >> build.sh
apt update
apt-get install -y libelf-dev build-essential pkg-config bc bison flex libssl-dev kmod
cd linux-raspberrypi-kernel_1.20200512-2
make bcm2711_defconfig 
make prepare 
make scripts
cd ../wireguard-linux-compat/src/
make -C /linux-raspberrypi-kernel_1.20200512-2 M=$PWD modules
exit
EOT
sudo chmod +x build.sh
}

post_chroot
wget http://cdimage.ubuntu.com/ubuntu-base/daily/current/groovy-base-arm64.tar.gz
tar -xzf groovy-base-arm64.tar.gz
wget https://github.com/raspberrypi/linux/archive/raspberrypi-kernel_1.20200512-2.zip
unzip raspberrypi-kernel_1.20200512-2.zip
git clone https://git.zx2c4.com/wireguard-linux-compat
cat /etc/resolv.conf > etc/resolv.conf
sudo mount -B /dev dev 
sudo mount -B /proc proc 
sudo mount -B /sys sys
sudo mount -t tmpfs tmp tmp
sudo chroot . ./build.sh
sudo cp wireguard-linux-compat/src/wireguard.ko /lib/modules/4.19.118-v8+/wireguard.ko
modprobe wireguard

wireguard.ko