resize-img

#!/bin/bash

#
# SPDX-License-Identifier: Apache-2.0
#
# Name:
#	Resize image utility
#
# Authors:
#	2018	Wes Huang	<Wes.Huang@moxa.com>
#	2019	Ken CJ Chou	<KenCJ.Chou@moxa.com>
#

set -e

VERSION=1.1.0
ORI_MNT_DIR="/tmp/original_mnt"
RES_MNT_DIR="/tmp/resized_mnt"
RES_IMAGE_NAME="resize.img"

usage() {
	echo -e "Usage:"
	echo -e "  # ${0} <image_type> <image_file>"
	echo -e ""
	echo -e "Parameters:"
	echo -e "  image_type"
	echo -e "    Image type must be A, B or C"
	echo -e "    Further informationcan be found at README"
	echo -e ""
	echo -e "  image_file"
	echo -e "    A image format file, usually with \".img\" file extension"
	echo -e ""
	echo -e "Example:"
	echo -e "  Resize a type A image which named \"example.img\""
	echo -e "  The output image file will be \"resize.img\""
	echo -e "    # ./resize-img A example.img"
	echo -e ""
	return 0
}

log_msg() {
	local msg=${1}

	echo -ne "\e[1;33m[resize-img]\e[0m "
	echo "${msg}"
	return 0
}

reset_image() {
	local image_type=${1}
	local mnt_dir=${2}

	if [ "${image_type}" == "A" ]; then
		if [ -f "${mnt_dir}/p2/sbin/expand2fs.bak" ]; then
			mv ${mnt_dir}/p2/sbin/expand2fs.bak ${mnt_dir}/p2/sbin/expand2fs
		fi
	else
		rm -f ${mnt_dir}/p3/v1/sbin_rw/upper/expand2fs.bak
		rm -f ${mnt_dir}/p3/v1/sbin_rw/upper/expand2fs
	fi

	return 0
}

resize_image() {
	local image_type=${1}
	local image=${2}
	local p1_size=32
	local p2_size
	local p3_size

	if ! [ -f "${image}" ]; then
		echo "image not found: ${image}" >&2
		return 2
	fi

	log_msg "Mounting original image"
	./mount-img mount "${image}" "${ORI_MNT_DIR}"

	log_msg "Calculating original image's partitions size"
	p2_size="$(du -s -BM "${ORI_MNT_DIR}/p2/")"
	p2_size="${p2_size%%M*}"
	p3_size="$(du -s -BM "${ORI_MNT_DIR}/p3/")"
	p3_size="${p3_size%%M*}"

	p2_size="$(( p2_size + p2_size / 5 ))"
	if [ "${image_type}" == "B" ] || [ "${image_type}" == "C" ]; then
		p3_size="$(( p3_size + p3_size / 5 ))"
	fi
	p3_size="$(( p3_size + 32 ))"

	log_msg "Creating new image"
	if [ "${image_type}" == "A" ]; then
		./create-img "${RES_IMAGE_NAME}" "1,${p1_size},y,b,vfat" "3,${p3_size},n,83,ext4" "2,${p2_size},n,83,ext4"
	elif [ "${image_type}" == "B" ]; then
		./create-img "${RES_IMAGE_NAME}" "1,${p1_size},y,b,vfat" "2,${p2_size},n,83,ext4" "3,${p3_size},n,83,ext4"
	else
		./create-img "${RES_IMAGE_NAME}" "1,${p1_size},y,83,ext4" "2,${p2_size},n,83,ext4" "3,${p3_size},n,83,ext4"
	fi

	log_msg "Mounting new image"
	./mount-img mount "${RES_IMAGE_NAME}" "${RES_MNT_DIR}"

	log_msg "Copying files"
	cp -a ${ORI_MNT_DIR}/p1/* ${RES_MNT_DIR}/p1/
	cp -a ${ORI_MNT_DIR}/p2/* ${RES_MNT_DIR}/p2/
	cp -a ${ORI_MNT_DIR}/p3/* ${RES_MNT_DIR}/p3/

	log_msg "Unmounting original image"
	./mount-img umount "${ORI_MNT_DIR}"

	log_msg "Resetting image"
	reset_image "${image_type}" "${RES_MNT_DIR}"

	log_msg "Unmounting new image"
	./mount-img umount "${RES_MNT_DIR}"

	log_msg "OK"
	return 0
}

main() {
	local option1=${1}
	local image=${2}
	local image_type

	case "${option1}" in
	"-v"|"--version")
		echo "${VERSION}"
		;;
	"a"|"A"|"b"|"B"|"c"|"C")
		if [ $# -ne 2 ]; then
			usage >&2
			return 1
		fi

		image_type="${option1^^}"
		resize_image "${image_type}" "${image}"
		;;
	*)
		usage >&2
		return 1
		;;
	esac

	return 0
}

if [ "${EUID}" -ne 0 ]; then
	echo "Please run as root" >&2
	exit 1
fi

main "$@"
exit 0