#!/bin/bash
DEST="$1"
CMD="$2"

if [[ ! -f "$DEST/boot/kernel.img" ]]; then
    echo "$DEST doesn't look like a RPI filesystem"
    exit 1
fi

cleanup()
{
    trap '' INT
    rm -f "$DEST/usr/bin/qemu-arm-static"
    cat /dev/null >"$DEST/etc/resolv.conf"
    echo "/usr/lib/arm-linux-gnueabihf/libcofi_rpi.so" >"$DEST/etc/ld.so.preload"
    rm -rf "$DEST/run/resolvconf"
    umount -l "$DEST/proc"
    umount -l "$DEST/dev"
    if [ "$DEST" = "/mnt" ]; then
        umount /mnt/boot /mnt
    fi
    exit 0
}

trap cleanup INT

mkdir -p "$DEST/run/resolvconf"
echo "nameserver 8.8.8.8" >"$DEST/etc/resolv.conf"
rm -f "$DEST/etc/ld.so.preload"

mount -o bind /proc "$DEST/proc"
mount -o bind /dev "$DEST/dev"

export QEMU_CPU=cortex-a15

cp /usr/bin/qemu-arm-static "$DEST/usr/bin"
if [ "$CMD" = "" ]; then
    HOME="/home/pi" chroot --userspec 1000:1000 $DEST
else
    HOME="/home/pi" chroot --userspec 1000:1000 $DEST $CMD
fi

cleanup