refind-installer.sh

#!/bin/sh 
[ "$BASH" ] && \
    export PS4='    +\t $BASH_SOURCE:$LINENO: ${FUNCNAME[0]:+${FUNCNAME[0]}():}'
######## CUSTOM SETTINGS #############

# modules to preload for the standalone grub
grub_modules=""

# name of configfile for grub to expect in mbusb.d/$distro
# .ref is automatically added to avoid self-sourcing via *.cfg
grub_standalone_config="refind-helper.cfg" 

# set the directory containing the iso's relative to the root of the USB device
# eg. /isos for /mnt/stick/isos/some.iso
# the default is multibootusb's setting /boot/isos
iso_dir="/boot/isos"

# change the location of the configfiles from multibootusb,
# relative to the root of the drive
# most of the time you can leave this unchanged
# Note, that this is relative to the /boot dir in the root of the device
mbusbd="/grub/mbusb.d"


### DON'T CHANGE STUFF BELOW THIS POINT ###
# Exit on errors and unbound variables
set -o nounset
set -o errexit

# Make sure only root can run this script
if [ "$(id -u)" -ne 0 ]; then
    echo "This script must be run as root" 1>&2
    echo "Trying with sudo now"
    exec sudo -k -- /bin/sh "$0" "$@" || cleanUp 2
fi

# Show usage
usage() {
    cat <<-EOF
        Usage: refind-multiboot-installer.sh [OPTIONS] [TARGET_DISK] eg. refind-multiboot-installer.sh /dev/sda1
        Install refind to a target drive and add a standalone efi bootloader for each iso file contained in the iso directory.

        device                      Device to install on
        -h, --help                  Display this message
        -s, --subdirectory <NAME>   Specify a data subdirectory (e.g. "boot" or "")
        -m, --mbusbdevice           Specify a device, in case mbusb.d does not reside on ESP

        Further options have to be edited in the CUSTOM section of this file.

        Note, that this script needs to be run as root.

EOF
}

# check for arguments 
parseArgs() {
    [ $# -eq 0 ] &&  usage && exit 0
    scriptname=$(basename "$0")
    data_subdir="/boot"
    esp_part="/dev/null"
    mbusb_part="/dev/null"
    use_extra_partition=false
    while [ "${#}" -gt 0 ]; do
        case "${1}" in
            # Show help
            -h|--help)
            showUsage
            exit 0
            ;;
        -m|--mbusbdevice)
            # if esp differs from data partition, use this
            mbusb_part="${2}"
            export use_extra_partitio=true
            shift
            shift
            ;;
        -s|--subdirectory)
            data_subdir="${2}"
            shift
            shift
            ;;
        /dev/*)
            if [ -b "${1}" ]; then
                esp_part="${1}"
            else
                printf '%s: %s is not a valid device.\n' "${scriptname}" "${1}" >&2
                cleanUp 1
            fi
            shift
            ;;
        *)
            printf '%s: %s is not a valid argument.\n' "${scriptname}" "${1}" >&2
            cleanUp 1
            ;;
    esac
done
if [ "${mbusb_part}" = "/dev/null" ] ;then
    mbusb_part="${esp_part}"
    use_extra_partition=false
fi
}
# Confirm the device
confirmDevice() {
    printf 'Are you sure you want to use %s? [y/N] ' "${esp_part}"
    read -r answer1
    case "${answer1}" in
        [yY][eE][sS]|[yY])
            echo "Alright..."
            ;;
        *)
            cleanUp 3
            ;;
    esac
}

checkIfMounted() {
    mount="$(lsblk -r -no MOUNTPOINT "${1}")"
    name="${2}"
    is_mounted=false
    is_mounted_by_script=false
    [ -z "${mount}" ] || is_mounted=true

}

mountDevice() {
    name="${2}"
    device="${1}"
    mount="/tmp/""${name}"
    mkdir "${mount}"
    mount "${device}" "${mount}" && is_mounted=true
    is_mounted_by_script=true

}

checkRefindInstalled() {
    # check if refind.conf is there, so we may skip reinstalling
    if [ -f "${esp_mount}/efi/boot/refind.conf" ]; then
        echo "Refind is already installed. Skipping install."
        refind_installed=true
    else
        refind_installed=false
    fi
}

# Make an EFI file to load with rEFInd
makeEFIfile() {
    # needed for external grub.cfg to work
    grub_modules="${grub_modules} ""part_gpt part_msdos regexp all_video"
    # create embedded grub.cfg
    echo "configfile \${cmdpath}/${grub_standalone_config}" > /tmp/grub.cfg
    [ -d "${script_path}/refind" ] || mkdir "${script_path}/refind"

    grub-mkstandalone \
        -O x86_64-efi\
        -o "${script_path}/refind/iso.efi" \
        --modules="${grub_modules}" \
        --locales="en@quot" \
        --compress="xz" \
        "boot/grub/grub.cfg=/tmp/grub.cfg"
    rm /tmp/grub.cfg
    # ^ embed /tmp/grub.cfg into memdisk as (memdisk)/boot/grub/grub.cfg
}

# create an additional configfile, so rEFInd finds our new bootloaders
createRefindIsoConf() {
    configstring=""
    refind_path="${esp_mount}/efi/boot"

    # Populate a list of entries to be looked at by rEFInd
    for confd in "${mbusbd}"/*.d; do
        relative_path="$(realpath --relative-to "${esp_mount}" "${confd}")"
        configstring="${configstring},""${relative_path}"
    done

    # write our file
    cat <<-EOT > "${refind_path}""/refind-iso.conf"
    ### This file will be overwritten by refind-multiboot-installer.sh
    ### If you want to add to this list, do so in refind.conf

    # Set our custom folders to be looked at by rEFInd
    # The comma after the colon is intended and circumvents a bug in rEFInd, where the first entry of a list is ignored.
    also_scan_dirs +${mbusb_uuid}:${configstring} 
EOT

# Make rEFInd source our file
# Add line to config, if it isn't there yet
line="include refind-iso.conf"
if ! grep -qF "${line}" "${refind_path}""/refind.conf" ;then
    echo -e "### source the config file for booting ISO files\n""${line}" >> "${refind_path}""/refind.conf"
fi
}

copyFiles() {
    echo -e "\nCopying files to target"
    for isofile in "${mbusb_mount}${iso_dir}"/*; do
        # parse name of distro
        filename="$(basename "${isofile}")"
        distro="$(awk -v file="${filename}" 'BEGIN{FS="-"; $0=file; print tolower($1)}')"
        ## check for existing config folders
        if [ -d "${mbusbd}/${distro}.d" ]; then
            echo "Creating config for \"""${distro}""\""
            createConfig "${mbusbd}/${distro}.d/${grub_standalone_config}"
            cp -f "${script_path}""/refind/iso.efi" "${mbusbd}""/""${distro}"".d/""${distro}"".efi"
            ## add icons to be copied, if refind offers no auto-detection
            #  ^ todo
            else
            echo "no matching folder found: " "${distro}" " -> " "${distro}.d"
        fi

    done
}
# Create the file that loads another grub.cfg to display menuentries
createConfig() {
    tee <<EOT > "${1}"
## GRUB CFG file for ISO boot helper

seach --no-floppy --set=root --fs-uuid ${mbusb_uuid}
set isopath=$iso_dir
imgdevpath=\$root
export isopath imgdevpath

for configfile in \$cmdpath/*.cfg; do
    source \$configfile
done

EOT

}

cleanUp() {
    for part in esp mbusb; do
        look_at_bool="${part}""_is_mounted_by_script"
        look_at_path="${part}""_mount"
        if [ "${look_at_bool}" = true ]; then
            # unmount
            umount -f "${look_at_path}" 2>/dev/null || true
            # remove dirs
            [ -d "${look_at_path}" ] && rmdir "${look_at_path}"
        fi
    done
    if [ "${refind_installed}" ] && [ -d /tmp/refind_install ]; then
        # unmount
        umount -f /tmp/refind_install
        # remove dir
        rmdir /tmp/refind_install
    fi
    # exit
    exit "${1-0}"
}


###########################################################
####                       Main                        ####
###########################################################

# Trap kill signals (SIGHUP, SIGINT, SIGTERM) to do some cleanup and exit
trap "cleanUp" 1 2 15
grub_standalone_config="${grub_standalone_config}"".ref"
script_path="$(dirname "$(realpath "${0}")")"
refind_installed=false
# Get UUID of partition, where mbusb.d resides
# Parse the arguments given
parseArgs "${@}"
confirmDevice

# Mount the device and get mountpoint, set config directory
#is_mounted="$("basename ${partition}")""_is_mounted"
checkIfMounted "${esp_part}" "esp"
if [ "${is_mounted}" ] ; then
    esp_mount="${mount}"

else
    mountDevice "${esp_part}" "esp"
    esp_mount="/tmp/esp"
    export esp_mounted_by_script="${is_mounted_by_script}"
fi

if [ ${use_extra_partition} ] ; then
    checkIfMounted "${mbusb_part}" "mbusb"
    if [ "${is_mounted}" ] ; then
        mbusb_mount="${mount}"
    else
        mountDevice "${mbusb_part}" "mbusb"
        mbusb_mount="/tmp/mbusb"
        export mbusb_mounted_by_script="${is_mounted_by_script}"
    fi
fi
#[ "${mbusb_part_is_mounted}" = true ] || mount-device "${mbusb_part}" "mbusb"

mbusbd="${mbusb_mount}${data_subdir}${mbusbd}"
mbusb_uuid="$(lsblk -r -no UUID "${mbusb_part}")"

# If rEFInd is not installed, do it
checkRefindInstalled
[ "$refind_installed" = true ] || refind-install --usedefault "${esp_part}"
# Add config file to rEFInd
createRefindIsoConf

# Build the EFI file once
[ -e "${script_path}"/refind/iso.efi ] ||  makeEFIfile "${script_path}"/refind/iso.efi 

# Copy EFI file and config to target
copyFiles

# Clean up and exit
cleanUp
echo "All done."
# vim:  set tabstop=2: set shiftwith=2: