#!/bin/bash

[ $# -eq 0 ] && { echo "Usage: $0 IMG_FILE"; exit 1; }

SECTOR_BYTES=512
SECTOR_START=2048
OFFSET=$(($SECTOR_BYTES*$SECTOR_START))

./build.sh
mkdir -p boot-part
sudo mount -o rw,loop,offset=$OFFSET $1 ./boot-part
tar -xzvf build/rpi-cloud-init.tgz -C boot-part
sudo umount ./boot-part
rmdir ./boot-part
rm -rf ./build