Step into a Foreign Image

apt install qemu-user-static

update-binfmts --display
arch="aarch64"
mnt="$(readlink -f ./mnt)"

mkdir -p "${mnt}"

# mount the target filesystem on ${mnt}

mount -t devtmpfs devtmpfs "${mnt}/dev"
mount -t devpts   devpts   "${mnt}/dev/pts"
mount -t tmpfs    tmpfs    "${mnt}/dev/shm"
mount -t proc     proc     "${mnt}/proc"
mount -t sysfs    sysfs    "${mnt}/sys"
mount -t tmpfs    tmpfs    "${mnt}/tmp"

mkdir ./overlay
mount -t tmpfs tmpfs ./overlay
mkdir ./overlay/{workdir,upperdir,mnt}

mount -t overlay -o lowerdir="$(readlink -f "./mnt/")",upperdir="$(readlink -f "./overlay/upperdir/")",workdir="$(readlink -f "./overlay/workdir/")" overlayfs ./overlay/mnt

cp "/usr/bin/qemu-${arch}-static" ./overlay/mnt/usr/bin/

chroot ./overlay/mnt/ /bin/sh

Work!

umount ./overlay/mnt
umount ./overlay
umount "${mnt}/tmp"
umount "${mnt}/sys"
umount "${mnt}/proc"
umount "${mnt}/dev/shm"
umount "${mnt}/dev/pts"
umount "${mnt}/dev"
umount "${mnt}"

See step_in.sh.