+build_rootfs()
+{
+(
+ sudo rm -rf testing
+ sudo eatmydata debootstrap --arch=arm64 --include iwd,tcpdump,vim,tmux,vlan,ntpdate,bridge-utils,parted,curl,wget,grub-efi-arm64,mtr-tiny,dbus,ca-certificates,sudo,openssh-client testing testing http://ftp.fau.de/debian
+
+ cd testing
+
+ sudo bash -c 'echo live > etc/hostname'
+
+ sudo bash -c 'echo > etc/motd'
+
+ sudo cp ../files/sources.list etc/apt/sources.list
+ sudo cp ../files/hosts etc/hosts
+ sudo cp ../files/quickstart.txt root/
+ sudo cp ../files/eth0 etc/network/interfaces.d/
+
+ sudo bash -c 'chroot . apt update'
+ sudo bash -c 'chroot . apt install -y firmware-linux'
+
+ sudo -- perl -p -i -e 's/root:x:/root::/' etc/passwd
+
+ sudo -- ln -s lib/systemd/systemd init