#!/usr/bin/env bash

usage() {
	printf "Usage: %s -k kernel -i initrd -v <1-2> -b bootargs -o output.firm" "$(basename "$0")"
	printf "\n\t-b ==> bootargs string"
	printf "\n\t-i ==> path to initrd uImage file"
	printf "\n\t-k ==> path to kernel uImage file"
	printf "\n\t-o ==> output .firm file"
	printf "\n\t-v ==> select C200 version (1 or 2)\n"
	return 1
}

while getopts "b:i:hk:o:v:" arg; do
	case $arg in
		b)
			BOOTARGS=$OPTARG
			;;
		i)
			INITRD=$OPTARG
			;;
		h)
			usage
			;;
		k)
			KERNEL=$OPTARG
			;;
		o)
			OUTPUT=$OPTARG
			;;
		v)
			VERSION=$OPTARG
			;;
		*)
			usage
	esac
done

if [ -z "${BOOTARGS}" ] || [ -z "${INITRD}" ] || [ -z "${KERNEL}" ] || \
[ -z "${OUTPUT}" ] || [ -z "${VERSION}" ]; then
	usage
fi

tmpdir=$(mktemp -d)

if [[ $VERSION == 1 ]]; then
	# Prepare header and trailer file for kernel
	echo "# CTera firmware information file" > $tmpdir/header || exit 1
	echo "image_type=kernel" >> $tmpdir/header
	echo "arch=Kirkwood" >> $tmpdir/header
	echo "board=Any" >> $tmpdir/header
	echo "version=3.1.22.30669" >> $tmpdir/header
	echo "kernel_cmd=${BOOTARGS}" >> $tmpdir/header
	echo "date=$(date)" >> $tmpdir/header
elif [[ $VERSION == 2 ]]; then
	# Prepare header and trailer file for kernel
	echo "# CTera firmware information file" > $tmpdir/header || exit 1
	echo "image_type=kernel" >> $tmpdir/header
	echo "arch=ARM" >> $tmpdir/header
	echo "board=2Drive_A" >> $tmpdir/header
	echo "version=5.5.165.61499" >> $tmpdir/header
	echo "kernel_cmd=${BOOTARGS}" >> $tmpdir/header
	echo "date=$(date)" >> $tmpdir/header
else
	echo "UNKNOWN VERSION!"
	exit 1
fi

cp $KERNEL $tmpdir/kernel || exit 1

echo "MD5=$(cat $tmpdir/header $tmpdir/kernel | md5sum)" > $tmpdir/trailer || exit 1

tar -H gnu -C $tmpdir -cf $tmpdir/output.tar header kernel trailer || exit 1

rm -rf $tmpdir/kernel $tmpdir/header $tmpdir/trailer || exit 1

if [[ $VERSION == 1 ]]; then
	# Prepare header and trailer file for fake romdisk
	echo "# CTera firmware information file" > $tmpdir/header || exit 1
	echo "image_type=romdisk" >> $tmpdir/header
	echo "initrd=yes" >> $tmpdir/header
	echo "arch=Kirkwood" >> $tmpdir/header
	echo "board=Any" >> $tmpdir/header
	echo "version=3.1.22.30669" >> $tmpdir/header
	echo "date=$(date)" >> $tmpdir/header
elif [[ $VERSION == 2 ]]; then
	# Prepare header and trailer file for fake romdisk
	echo "# CTera firmware information file" > $tmpdir/header || exit 1
	echo "image_type=romdisk" >> $tmpdir/header
	echo "initrd=yes" >> $tmpdir/header
	echo "arch=ARM" >> $tmpdir/header
	echo "board=2Drive_A" >> $tmpdir/header
	echo "version=5.5.165.61499" >> $tmpdir/header
	echo "date=$(date)" >> $tmpdir/header
else
	echo "UNKNOWN VERSION!"
	exit 1
fi

cp $INITRD $tmpdir/romdisk || exit 1

echo "MD5=$(cat $tmpdir/header $tmpdir/romdisk | md5sum)" > $tmpdir/trailer || exit 1

tar -H gnu -C $tmpdir -rf $tmpdir/output.tar header romdisk trailer || exit 1
rm -rf $tmpdir/romdisk $tmpdir/header $tmpdir/trailer || exit 1

mv $tmpdir/output.tar $OUTPUT || exit 1

echo "Done"