#!/bin/bash
set -e

ROOTFS=$1

if [[ -z "$ROOTFS" ]] || [[ ! -d "$ROOTFS/usr/bin" ]]; then
    echo "[!] Invalid rootfs argument: '$ROOTFS'"
    exit 1
fi

cleanup() {
    echo "[*] Cleaning up..."
    for sub in dev/pts dev proc sys run; do
        if mountpoint -q "$ROOTFS/$sub"; then
            echo "    Unmounting $ROOTFS/$sub"
            sudo umount "$ROOTFS/$sub" || true
        fi
    done
}
trap cleanup EXIT

echo "[+] Binding chroot filesystems..."
for fs in dev dev/pts proc sys run; do
  sudo mount --bind "/$fs" "$ROOTFS/$fs"
done

echo "[+] Ensuring /etc/resolv.conf for DNS inside chroot"
sudo cp /etc/resolv.conf "$ROOTFS/etc/resolv.conf"

echo "[+] Entering your chroot shell..."
echo "Type exit to leave"
sudo chroot "$ROOTFS" /usr/bin/qemu-aarch64-static /bin/bash