Build a 64bit Debian OS for the Raspberry Pi using Debootstrap

rpi-debootstrap.sh

#!/usr/bin/env bash

set -xeo pipefail;

IMAGE_SIZE=2000M
BOOT_SIZE=256M
IMAGE_ARCH=arm64

while getopts "s:" option; do
	case $option in
		a)
			IMAGE_ARCH="${OPTARG}";
		;;
		b)
			BOOT_SIZE="${OPTARG}";
		;;
		s)
			IMAGE_SIZE="${OPTARG}";
		;;
		:)
			echo "option ${OPTARG} requires an argument";
		;;
		?)
			exit 1;
		;;
	esac;
done
shift $(($OPTIND - 1));

_rname=$(openssl rand -hex 8);

truncate -s${IMAGE_SIZE} ${_rname}.img;

sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << EOF | fdisk ${_rname}.img
	p
	o # delete all
	n # NEW /boot   /dev/xxx1
	p # primary partition
	1 # partition number 1
	# auto first sector
	+${BOOT_SIZE} # arg size /boot part
	a # make partition bootable
	p
	n # NEW /       /dev/xxx2
	p # primary partition
	2 # partion number 2
	# auto first sector
	# auto part2 size 100%
	p
	w # write the partition table
	q
EOF
unset EOF;
_lofree=$(losetup -f);

losetup -P ${_lofree} ${_rname}.img;

trap 'umount -r ./mnt; umount -r ${_lofree}; losetup -d ${_lofree}; rm -vf ${_rname}.img' ERR;

mkfs.vfat "${_lofree}p1";
mkfs.ext4 "${_lofree}p2";

partprobe ${_lofree};

fdisk -l ${_lofree};

rm -vrf ./mnt;
mkdir mnt;
mount ${_lofree}p2 ./mnt;
mkdir -vp mnt/boot;
mount ${_lofree}p1 ./mnt/boot;

debootstrap --include=apt-utils,ca-certificates,gnupg,less,locales,nano,netbase,ntp,ifupdown,inetutils-ping,iproute2,irqbalance,openssh-server,passwd,psmisc,sudo,sysvinit-core,wget,whiptail,wpasupplicant --arch="${IMAGE_ARCH}" buster ./mnt "http://deb.debian.org/debian";
if [[ "${IMAGE_ARCH}" == "arm64" ]]; then
	cp -v $(which qemu-aarch64-static) ./mnt/usr/bin/;
else
	cp -v $(which qemu-${IMAGE_ARCH}-static) ./mnt/usr/bin/;
fi

mount -t proc /proc ./mnt/proc/;
mount -t sysfs /sys ./mnt/sys/;
mount -o bind /dev ./mnt/dev/;

printf 'deb http://deb.debian.org/debian stable main contrib non-free
deb http://deb.debian.org/debian stable-updates main contrib non-free
deb http://security.debian.org/ stable/updates main contrib non-free' | tee ./mnt/etc/apt/sources.list;

cat <<EOF | LANG=C.UTF-8 TERM=xterm DEBIAN_FRONTEND=noninteractive chroot ./mnt /bin/bash
	apt-get update;
	apt-get dist-upgrade -y;
	apt-get install -y binutils byobu curl xz-utils;
EOF
unset EOF;

printf 'auto lo
iface lo inet loopback
iface lo inet6 loopback

auto eth0
iface eth0 inet dhcp
iface eth0 inet6 auto

allow-hotplug wlan0
iface wlan0 inet dhcp
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf' | tee ./mnt/etc/network/interfaces;

printf 'nameserver 1.1.1.1
nameserver 1.0.0.1' | tee ./mnt/etc/resolv.conf;

printf 'proc\t/proc\tproc\tdefaults\t0\t0
/dev/mmcblk0p1\t/boot\tvfat\tdefaults\t0\t2
/dev/mmcblk0p2\t/\text4\tdefaults,noatime\t0\t1' | tee ./mnt/etc/fstab;

cat <<EOF | LANG=C.UTF-8 TERM=xterm DEBIAN_FRONTEND=noninteractive chroot ./mnt /bin/bash
	apt-get install -y crda fake-hwclock firmware-brcm80211 firmware-linux-free firmware-linux-nonfree net-tools usb-modeswitch ssh;
	mkdir -vp /lib/firmware/bcrm;
	cd /lib/firmware/bcrm;
	wget https://raw.githubusercontent.com/RPi-Distro/firmware-nonfree/master/brcm/brcmfmac43455-sdio.txt;
	wget https://github.com/RPi-Distro/firmware-nonfree/raw/master/brcm/brcmfmac43455-sdio.clm_blob;
	wget https://raw.githubusercontent.com/RPi-Distro/firmware-nonfree/master/brcm/brcmfmac43430-sdio.txt;
	wget -O brcmfmac43430-sdio.raspberrypi,3-model-b.txt https://raw.githubusercontent.com/RPi-Distro/firmware-nonfree/master/brcm/brcmfmac43430-sdio.raspberrypi-rpi.txt;
	useradd -s /bin/bash -d /home/pi -G sudo pi;
	echo pi:raspberry | chpasswd;
	wget -O /usr/local/bin/rpi-update https://raw.githubusercontent.com/Hexxeh/rpi-update/master/rpi-update;
	chmod -v +x /usr/local/bin/rpi-update;
	yes | WANT_PI4=1 /usr/local/bin/rpi-update;
EOF
unset EOF;

printf 'dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline fsck.repair=yes rootwait net.ifnames=0' | tee ./mnt/boot/cmdline.txt
printf 'kernel=kernel8.img\ngpu_mem=16\narm_64bit=1\ndtoverlay=vc4-fkms-v3d' | tee ./mnt/boot/config.txt

umount -r ./mnt;
umount -f ${_lofree};
losetup -d ${_lofree};