update-tool-create-bundle

#!/bin/bash
# SPDX-License-Identifier: MIT

# This generates an update bundle conatining the images, a manifest with the
# SHA256 sums of each image. The bundle can then be given as parameter to the update-tool.
#
# There shall be at least one image given which will be part of the bundle.
# The single image parameters this script gets called with, must match with
# the set number. If a set shall be skipped, because the image will not be
# part of the bundle, its parameter shall be set to '-'.
#
# Examples:
#  To update set bootloader and bootfs, you might call the tool with:
#
#    update-tool-create-bundle.sh bootloader:/<PATH>/bootloader bootfs:/<PATH>/fit.img

SCRIPT_VERSION="0.1"
SCRIPT_NAME=$(basename "$0")

SCRIPT_USAGE=$(cat <<EOF
Usage: ${SCRIPT_NAME} [-hvrzcsSm] [<set_name>:<image_path>..]

Generates an update bundle containing all given images and a manifest file
describing the contained images and providing checksums for all images.

Example:
    ${SCRIPT_NAME} --allow-rollback -z --sha256 -c bootfs:fit.img rootfs:../root.img

-h|--help:
    Displays this help.
--version:
    Displays the current version of this script.
-v|--verbose:
    Display additional information.
-r|--allow-rollback:
    Whether or not a rollback to an older system is allowed.
-z|--zipped
    Zip the resulting update bundle.
-c|--cleanup:
    Remove the temporary files.
-s|--sha256:
    Generate SHA256 checksums for each image. (Default)
-S|--sha1:
    Generate SHA1 checksums for all images.
-m|--md5:
    Generate MD5 checksums for all images.
EOF
)

# Helper functions.
error() {
    printf "Error: %s\n" "$@" 1>&2
}

info() {
    if [ ${VERBOSE_INFO} -ne 0 ]; then
        echo "$@"
    fi
}

usage() {
    rc=0

    if [ -n "${1}" ]; then
        rc="${1}"
    fi

    if [ -n "${2}" ]; then
        error "${2}"
    fi

    echo "${SCRIPT_USAGE}"

    exit "${rc}"
}

absolute_path() {
    cd "$(dirname "${1}")" || exit
    case $(basename "${1}") in
        ..) dirname "$(pwd)";;
        .)  pwd;;
        *)  echo "$(pwd)/$(basename "${1}")";;
    esac
}

CHECKSUM_CMD=""
VERBOSE_INFO=0
ROLLBACK=0
CLEANUP=0
ZIPPED=0

while [ -n "${1+xxx}" ]; do
    case "${1}" in
        --help|-h)
            usage
            ;;
        --version)
            echo "${SCRIPT_NAME} v${SCRIPT_VERSION}"
            exit 0
            ;;
        --verbose|-v)
            VERBOSE_INFO=1
            ;;
        -r|--allow-rollback)
            ROLLBACK=1
            ;;
        -z|--zipped)
            ZIPPED=1
            ;;
        -c|--cleanup)
            CLEANUP=1
            ;;
        --sha256|-s)
            if [ -n "${CHECKSUM_CMD}" ]; then
                usage 1 "Cannot use more than one checksum type."
            fi

            CHECKSUM_CMD="sha256sum"
            ;;
        --sha1|-S)
            if [ -n "${CHECKSUM_CMD}" ]; then
                usage 1 "Cannot use more than one checksum type."
            fi

            CHECKSUM_CMD="sha1sum"
            ;;
        --md5|-m)
            if [ -n "${CHECKSUM_CMD}" ]; then
                usage 1 "Cannot use more than one checksum type."
            fi

            CHECKSUM_CMD="md5sum"
            ;;
        --)
            shift
            break
            ;;
        -*)
            usage 1 "Unrecognized option ${1}."
            ;;
        *)
            break
            ;;
    esac

    shift
done

if [ -z "${CHECKSUM_CMD}" ]; then
    CHECKSUM_CMD="sha256sum"
fi

# Ensure at least one image name is given.
if [ $# -lt 1 ]; then
    usage 1 "Invalid number of arguments."
fi

IMAGES=""
CHECKSUM_TYPE="${CHECKSUM_CMD%"sum"}"

cat <<'EOF' > Manifest.json
{
    "version": "3",
EOF

if [ "${ROLLBACK}" -eq 1 ]; then
    printf "    \"rollback-allowed\": true,\n" >> Manifest.json
else
    printf "    \"rollback-allowed\": false,\n" >> Manifest.json
fi


printf "    \"images\": [\n" >> Manifest.json

while [ -n "${1+xxx}" ]; do
    IFS=':' read -r SET_NAME IMAGE_FILE  < <(echo "${1}")
    if [ -z "${SET_NAME}" ] || [ -z "${IMAGE_FILE}" ]; then
        usage 1 "'${1}' is not a valid image description. Should be \"<set_name>:<image_file>\"."
    fi

    IMAGE_PATH="$(absolute_path "${IMAGE_FILE}")"
    if ! [ -f "${IMAGE_PATH}" ]; then
        usage 1 "Image ${IMAGE_PATH} does not exist"
    fi

    info "Calculating ${CHECKSUM_TYPE} of ${IMAGE_FILE}"
    CHECKSUM=$("${CHECKSUM_CMD}" "${IMAGE_PATH}" | cut -d ' ' -f 1)

    if [ -n "${IMAGES}" ]; then
        printf "%s,\n" "$(< Manifest.json)" > Manifest.json
    fi

cat <<EOF >> Manifest.json
        {
            "name": "${SET_NAME}",
            "filename": "$(basename "${IMAGE_FILE}")",
            "${CHECKSUM_TYPE}": "${CHECKSUM}"
        }
EOF

    IMAGES="${IMAGES} -C $(dirname "${IMAGE_PATH}") $(basename "${IMAGE_PATH}")"

    shift
done

printf "    ]\n}\n" >> Manifest.json

if [ -z "${IMAGES}" ]; then
    usage 1 "No images provided."
fi

# shellcheck disable=SC2086
tar cf bundle.tar Manifest.json $IMAGES >/dev/null
if [ $? -ne 0 ]; then
    error "Creation of update bundle failed."
    exit 1
fi

if [ "${ZIPPED}" -eq 1 ]; then
    info "Compressing update bundle ..."
    gzip --keep --force bundle.tar
fi

if [ "${CLEANUP}" -eq 1 ]; then
    info "Removing temporary files ..."
    rm bundle.tar Manifest.json
fi

if [ "${ZIPPED}" -eq 1 ]; then
    echo "Update-package 'bundle.tar.gz' is ready now"
else
    echo "Update-package 'bundle.tar' is ready now"
fi