Correct typo

Update Readme
* Update Description section: Adds experimental method for booting to a snapshot in read-only mode with systemd. * Update Installation section: Adds : Run make help to check what options are available. Adds new dependency: strings
2026-03-05 05:35:01 +08:00 · 2021-11-26 17:22:27 +01:00 · 2021-11-26 17:20:26 +01:00 · 2021-11-26 16:55:53 +01:00 · 2021-11-26 16:47:04 +01:00 · 2021-11-26 02:49:37 +01:00
12 changed files with 1082 additions and 112 deletions
--- a/687
+++ b/687
@@ -1,117 +1,586 @@
-#! /bin/sh
+#! /usr/bin/env bash
+#
+# Written by: Antynea
+# BTC donation address: 1Lbvz244WA8xbpHek9W2Y12cakM6rDe5Rt
+# Github: https://github.com/Antynea/grub-btrfs
+#
+# Purpose:
+#   Improves Grub by adding "btrfs snapshots" to the Grub menu.
+#   You can boot your system on a "snapshot" from the Grub menu.
+#   Supports manual snapshots, snapper, timeshift ...
+#   Warning : booting on read-only snapshots can be tricky.
+#   (Read about it, https://github.com/Antynea/grub-btrfs#warning-booting-on-read-only-snapshots-can-be-tricky)
+#
+# What this script does:
+# - Automatically List snapshots existing on root partition (btrfs).
+# - Automatically Detect if "/boot" is in separate partition.
+# - Automatically Detect kernel, initramfs and intel/amd microcode in "/boot" directory on snapshots.
+# - Automatically Create corresponding "menuentry" in grub.cfg.
+# - Automatically detect the type/tags and descriptions/comments of snapper/timeshift snapshots.
+# - Automatically generate grub.cfg if you use the provided systemd service.
+#
+# Installation:
+# - Refer to https://github.com/Antynea/grub-btrfs#installation-
+#
+# Customization:
+#  You have the possibility to modify many parameters in /etc/default/grub-btrfs/config.
+#
+# Automatically update Grub
+#  If you would like grub-btrfs menu to automatically update when a snapshot is created or deleted:
+#  - Refer to https://github.com/Antynea/grub-btrfs#automatically-update-grub.
+#
+# Special thanks for assistance and contributions:
+# - My friends
+# - All contributors on Github
+#
+
 set -e

-. /usr/share/grub/grub-mkconfig_lib
-. /etc/default/grub
+sysconfdir="/etc"
+grub_btrfs_config="${sysconfdir}/default/grub-btrfs/config"

-### variables modifiable ###
-## fr: nom du sous-menu 
-## en: Name of the submenu
-submenuname="ArchLinux Snapshots"
-## fr: préfixe de l'entrée 
-## en: Prefix entry
-prefixentry="Snapshot"
-## fr: nom(s) du ou des kernel(s)
-## en: Name(s) of the kernel(s)
-nkernel=("vmlinuz-linux")
-## fr: nom(s) de(s) l'init
-## en: Name(s) of the init(s)
-ninit=("initramfs-linux.img" "initramfs-linux-fallback.img")
+[[ -f "$grub_btrfs_config" ]] && . "$grub_btrfs_config"
+[[ -f "${sysconfdir}/default/grub" ]] && . "${sysconfdir}/default/grub"

+## Exit the script, if:
+[[ "${GRUB_BTRFS_DISABLE,,}" == "true" ]] && exit 0 # Disable Grub-btrfs is set to true (default=false)
+if ! type btrfs >/dev/null 2>&1; then exit 0; fi # btrfs-progs isn't installed
+[[ -f "${GRUB_BTRFS_MKCONFIG_LIB:-/usr/share/grub/grub-mkconfig_lib}" ]] && . "${GRUB_BTRFS_MKCONFIG_LIB:-/usr/share/grub/grub-mkconfig_lib}" || exit 0 # grub-mkconfig_lib couldn't be found
+# Root filesystem isn't btrfs
+root_fs=$(${grub_probe} --target="fs" / 2>/dev/null)
+[[ "$root_fs" != "btrfs" ]] && exit 0

-###########################
-### fr: DÉBUT DU SCRIPT ###
-### en: NAME OF SCRIPT  ###
-### fr: NE PAS TOUCHER  ###
-### en: DO NOT TOUCH    ###
-###########################
-## fr: internationalisation
-## en: Internationalization
-export TEXTDOMAIN=grub-btrfs-git
-export TEXTDOMAINDIR="/usr/share/locale"
-## fr: paramêtre des chaînes --hint
-## en: Parameter of the chains --hint (Translation unclear)
-pboot=$(${grub_probe} --target="hints_string" "/boot" 2>/dev/null)
-## fr: uuid de la partition root
-## en: UUID of the root partition
-uuid=$(${grub_probe} "/" --target="fs_uuid" 2>/dev/null)
-## fr: uuid de la partition boot
-## en: UUID of the boot partition
-buuid=$(${grub_probe} --target="fs_uuid" "/boot" 2>/dev/null)
-## fr: paramêtre passé au kernel
-## en: Parameters passed to the kernel
-params="$GRUB_CMDLINE_LINUX $GRUB_CMDLINE_LINUX_DEFAULT"
+## Error Handling
+print_error()
+{
+    local err_msg="$*"
+    local bug_report="If you think an error has occurred , please file a bug report at \" https://github.com/Antynea/grub-btrfs \""
+    printf "%s\n" "${err_msg}" "${bug_report}" >&2 ;
+    exit 0
+}

+printf "Detecting snapshots ...\n" >&2 ;

-# fr: on affiche le menu
-# en: Display the menu
-echo "submenu '$submenuname' {"
+## Submenu name
+distro=$(awk -F "=" '/^NAME=/ {gsub(/"/, "", $2); print $2}' /etc/os-release)
+submenuname=${GRUB_BTRFS_SUBMENUNAME:-"${distro:-Linux} snapshots"}
+## Limit snapshots to show in the Grub menu (default=50)
+limit_snap_show="${GRUB_BTRFS_LIMIT:-50}"
+## How to sort snapshots list
+btrfs_subvolume_sort="--sort=${GRUB_BTRFS_SUBVOLUME_SORT:-"-rootid"}"
+## Customize GRUB directory, where "grub.cfg" file is saved
+grub_directory=${GRUB_BTRFS_GRUB_DIRNAME:-"/boot/grub"}
+## Customize BOOT directory, where kernels/initrams/microcode is saved.
+boot_directory=${GRUB_BTRFS_BOOT_DIRNAME:-"/boot"}
+## Password protection management for submenu
+# Protection support for submenu (--unrestricted)
+case "${GRUB_BTRFS_DISABLE_PROTECTION_SUBMENU,,}" in
+    true)   unrestricted_access_submenu="--unrestricted ";;
+    *)      unrestricted_access_submenu=""
+esac
+# Authorized users (--users foo,bar)
+if [ -n "${GRUB_BTRFS_PROTECTION_AUTHORIZED_USERS}" ] ; then
+    protection_authorized_users="--users ${GRUB_BTRFS_PROTECTION_AUTHORIZED_USERS} "
+fi

-# fr: on traite la variable kernel
-# en: Treat the kernel variables (Translation unclear)
-for kernel in ${nkernel[@]}; do
-	# fr: on test si le(s) nom(s) du(des) kernel existe(nt), autrement on affiche une erreur et on sort
-	# en: Check the specified kernel(s) exist, if it/they don't, display an error and exit
-	if [ ! -f /boot/$kernel ]; then gettext_printf $"Error: /boot/$kernel, kernel does not exist" >&2; exit 1; fi
-	# fr: on vérifie le nombre de kernel présent, si >1 on crée un menu
-	# en: If there are >1 kernels, create a menu
-	if [ ${#nkernel[*]} != 1 ]; then echo "	submenu '$kernel' {
-		submenu '---> Kernel: $kernel <---' { echo }"; fi
-	
-	# fr: On liste les snapshots présent sur le système de fichier
-	# en: List filesystem snapshots
-	for item in $($bindir/btrfs subvolume list -s / --sort=-ogen | $bindir/awk '{print $NF}'); do
-		# fr: On écarte les snapshots avec un statut de suppression
-		# en: Discard deleted snapshots
-		if [ $item = "DELETED" ]; then continue; fi
-		# fr: affiche la liste des snapshots trouvés
-		# en: Output name of snapshot
-		gettext_printf $"Found Snapshot: %s\n" "$item" >&2
-		# fr: on crée un menu pour chaque snapshot présent (nom + date de création)
-		# en: Create a menu for remaining snapshots (name + creation date)
-		date_time=$($bindir/btrfs subvolume list -s / | $bindir/grep $item | $bindir/cut -d" " -f 11-12)
-		echo "		submenu '$prefixentry $item [$date_time]' {"
-		# fr: si plusieurs kernel on été trouvé, on affiche un titre indicatif
-		# en: if more than one kernel is found, create a menu
-		if [ ${#nkernel[*]} != 1 ]; then echo "			submenu '---> Kernel: $kernel <---' { echo }"; fi
-		# fr: on traite la variable de l'initramfs
-		# en: Treat the initramfs variables (Translation unclear)
-		for init in ${ninit[@]}; do
-			# fr: on test si le(s) nom(s) du(des) initramfs existe(nt), autrement on affiche une erreur et on sort
-			# en: Check the specified initramfs(es) exist, if it/they don't, display an error and exit
-			if [ ! -f /boot/$init ]; then gettext_printf $"Error: /boot/$init, initramfs does not exist" >&2; exit 1; fi
-			# fr: on traite chaque entrée des snapshots avec leurs kernel et initramfs respectifs
-			# en: Specify a kernel and initramfs for every snapshot
-			echo "\
-			menuentry '$item $init' --class arch --class gnu-linux --class gnu --class os "\$menuentry_id_option" 'gnulinux-snapshots-$uuid'{
-				load_video
-				set gfxpayload=$GRUB_GFXPAYLOAD_LINUX
-				if [ x"\$feature_platform_search_hint" = xy ]; then
-					search --no-floppy --fs-uuid --set=root $pboot $buuid
-				else
-					search --no-floppy --fs-uuid --set=root $buuid
-				fi
-				echo	'Loading Linux snapshot ...'"
-				# fr: on vérifie l'emplacement de la partition /boot
-				# en: Check the location of the /boot partition
-				if [ $uuid = $buuid ]; then
-					echo "\
-				linux	/$item/boot/$kernel root=UUID=$uuid rw rootflags=subvol=$item $params
-				echo    'Loading initial ramdisk ...'
-				initrd	/$item/boot/$init"
-				else
-					echo "\
-				linux	/$kernel root=UUID=$uuid rw rootflags=subvol=$item $params
-				echo    'Loading initial ramdisk ...'
-				initrd  /$init"
-				fi
-				echo "\
-			}"
-		done
-		echo "		}"
-	done
-	# fr: on oubli pas de fermer le menu si plusieurs kernels ont été trouvé
-	# en: Don't forget to close menus if more than one kernel is found
-	if [ ${#nkernel[*]} != 1 ]; then echo "	}"; fi
-done
-echo "}"
+## Probe informations of Root and Boot devices
+# Probe info "Root partition"
+root_device=$(${grub_probe} --target=device /) # Root device
+root_uuid=$(${grub_probe} --device ${root_device} --target="fs_uuid" 2>/dev/null) # UUID of the root device
+root_uuid_subvolume=$(btrfs subvolume show / 2>/dev/null) || print_error "UUID of the root subvolume is not available"; # If UUID of root subvolume is not available, then exit
+root_uuid_subvolume=$(awk -F":" 'match($1, /(^[ \t]+UUID)/) {sub(/^[ \t]+/, "", $2); print $2}' <<< "$root_uuid_subvolume") # UUID of the root subvolume
+# Probe info "Boot partition"
+boot_device=$(${grub_probe} --target=device ${boot_directory}) # Boot device
+boot_uuid=$(${grub_probe} --device ${boot_device} --target="fs_uuid" 2>/dev/null) # UUID of the boot device
+boot_uuid_subvolume=$(btrfs subvolume show "$boot_directory" 2>/dev/null) || boot_uuid_subvolume=" UUID: $root_uuid_subvolume"; # If boot folder isn't a subvolume, then UUID=root_uuid_subvolume
+boot_uuid_subvolume=$(awk -F":" 'match($1, /(^[ \t]+UUID)/) {sub(/^[ \t]+/, "", $2); print $2}' <<< "$boot_uuid_subvolume") # UUID of the boot subvolume
+boot_hs=$(${grub_probe} --device ${boot_device} --target="hints_string" 2>/dev/null) # hints string
+boot_fs=$(${grub_probe} --device ${boot_device} --target="fs" 2>/dev/null) # Type filesystem of boot device
+
+## Parameters passed to the kernel
+kernel_parameters="$GRUB_CMDLINE_LINUX $GRUB_CMDLINE_LINUX_DEFAULT"
+## Mount point location
+grub_btrfs_mount_point=$(mktemp -dt grub-btrfs.XXXXXXXXXX)
+## Class for theme
+CLASS="--class snapshots --class gnu-linux --class gnu --class os"
+## save IFS
+oldIFS=$IFS
+## Detect uuid requirement (lvm,btrfs...)
+check_uuid_required() {
+if [ "x${root_uuid}" = "x" ] || [ "x${GRUB_DISABLE_LINUX_UUID}" = "xtrue" ] \
+    || ! test -e "/dev/disk/by-uuid/${root_uuid}" \
+    || ( test -e "${root_device}" && uses_abstraction "${root_device}" lvm ); then
+    LINUX_ROOT_DEVICE=${root_device}
+else
+    LINUX_ROOT_DEVICE=UUID=${root_uuid}
+fi
+}
+## Detect rootflags
+detect_rootflags()
+{
+    local fstabflags=$(grep -oE '^\s*[^#][[:graph:]]+\s+/\s+btrfs\s+[[:graph:]]+' "${grub_btrfs_mount_point}/${snap_dir_name_trim}/etc/fstab" \
+                        | sed -E 's/^.*[[:space:]]([[:graph:]]+)$/\1/;s/,?subvol(id)?=[^,$]+//g;s/^,//')
+    rootflags="rootflags=${fstabflags:+$fstabflags,}${GRUB_BTRFS_ROOTFLAGS:+$GRUB_BTRFS_ROOTFLAGS,}"
+}
+
+unmount_grub_btrfs_mount_point()
+{
+if [[ -d "$grub_btrfs_mount_point" ]]; then
+    local wait=true
+    local wait_max=0
+    printf "Unmount %s .." "$grub_btrfs_mount_point" >&2;
+    while $wait; do
+        if grep -qs "$grub_btrfs_mount_point" /proc/mounts; then
+            wait_max=$((1+wait_max))
+            if umount "$grub_btrfs_mount_point" >/dev/null 2>&1; then
+                wait=false # umount successful
+                printf " Success\n" >&2;
+            elif [[ $wait_max = 10 ]]; then
+                printf "\nWarning: Unable to unmount %s in %s\n" "$root_device" "$grub_btrfs_mount_point" >&2;
+                break;
+            else
+                printf "." >&2 ; # output to show that the script is alive
+                sleep 2 # wait 2 seconds before retry
+            fi
+        else
+            wait=false # not mounted
+            printf " Success\n" >&2;
+        fi
+    done
+    if [[ "$wait" != true ]]; then
+        if ! rm -d "$grub_btrfs_mount_point" >/dev/null 2>&1; then
+            printf "Unable to delete %s: Device or ressource is busy\n" "$grub_btrfs_mount_point" >&2;
+        fi
+    fi
+fi
+}
+
+## Create entry
+entry()
+{
+echo "$@" >> "$grub_directory/grub-btrfs.new"
+}
+
+## menu entries
+old_kernel_parameters=${kernel_parameters}
+make_menu_entries()
+{
+    kernel_parameters="${old_kernel_parameters}"
+    if [[ "${GRUB_BTRFS_SYSTEMD_VOLATILE}" == true ]] ; then
+        if [[ $(strings -n7 "$grub_btrfs_mount_point/$snap_dir_name_trim/usr/bin/init" | grep -aEiom1 'upstart|systemd|sysvinit') == systemd ]] \
+           || [[ $(strings -n7 "$grub_btrfs_mount_point/$snap_dir_name_trim/sbin/init" | grep -aEiom1 'upstart|systemd|sysvinit') == systemd ]]; then
+                [[ $(btrfs property get "$grub_btrfs_mount_point/$snap_dir_name_trim" ro) != "ro=false" ]] && kernel_parameters="${kernel_parameters} systemd.volatile=state";
+        fi
+    fi
+## \" required for snap,kernels,init,microcode with space in their name
+    entry "submenu '${title_menu}' {
+    submenu '${title_submenu}' { echo }"
+    for k in "${name_kernel[@]}"; do
+        [[ ! -f "${boot_dir}"/"${k}" ]] && continue;
+        kversion=${k#*"-"}
+        for i in "${name_initramfs[@]}"; do
+            if [[ "${name_initramfs}" != "x" ]] ; then
+                # prefix_i=${i%%"-"*}
+                suffix_i=${i#*"-"}
+                # alt_suffix_i=${i##*"-"}
+                if   [ "${kversion}" = "${suffix_i}" ];                 then i="${i}";
+                elif [ "${kversion}.img" = "${suffix_i}" ];             then i="${i}";
+                elif [ "${kversion}-fallback.img" = "${suffix_i}" ];    then i="${i}";
+                elif [ "${kversion}.gz" = "${suffix_i}" ];              then i="${i}";
+                else continue;
+                fi
+                for u in "${name_microcode[@]}"; do
+                    if [[ "${name_microcode}" != "x" ]] ; then
+                    entry "
+    menuentry '  "${k}" & "${i}" & "${u}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid' {"
+                    else
+                    entry "
+    menuentry '  "${k}" & "${i}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid' {"
+                    fi
+                    entry "\
+        if [ x\$feature_all_video_module = xy ]; then
+        insmod all_video
+        fi
+        set gfxpayload=keep
+        insmod ${boot_fs}
+        if [ x\$feature_platform_search_hint = xy ]; then
+            search --no-floppy --fs-uuid  --set=root ${boot_hs} ${boot_uuid}
+        else
+            search --no-floppy --fs-uuid  --set=root ${boot_uuid}
+        fi
+        echo 'Loading Snapshot: "${snap_date_trim}" "${snap_dir_name_trim}"'
+        echo 'Loading Kernel: "${k}" ...'
+        linux \"${boot_dir_root_grub}/"${k}"\" root="${LINUX_ROOT_DEVICE}" ${kernel_parameters} ${rootflags}subvol=\""${snap_dir_name_trim}"\""
+                    if [[ "${name_microcode}" != "x" ]] ; then
+                        entry "\
+        echo 'Loading Microcode & Initramfs: "${u}" "${i}" ...'
+        initrd \"${boot_dir_root_grub}/"${u}"\" \"${boot_dir_root_grub}/"${i}"\""
+                    else
+                        entry "\
+        echo 'Loading Initramfs: "${i}" ...'
+        initrd \"${boot_dir_root_grub}/"${i}"\""
+                    fi
+                    entry "    }"
+                    count_warning_menuentries=$((1+count_warning_menuentries))
+                done
+            else
+                for u in "${name_microcode[@]}"; do
+                    if [[ "${name_microcode}" != "x" ]] ; then
+                    entry "
+    menuentry '  "${k}" & "${u}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid' {"
+                    else
+                    entry "
+    menuentry '  "${k}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid' {"
+                    fi
+                    entry "\
+        if [ x\$feature_all_video_module = xy ]; then
+        insmod all_video
+        fi
+        set gfxpayload=keep
+        insmod ${boot_fs}
+        if [ x\$feature_platform_search_hint = xy ]; then
+            search --no-floppy --fs-uuid  --set=root ${boot_hs} ${boot_uuid}
+        else
+            search --no-floppy --fs-uuid  --set=root ${boot_uuid}
+        fi
+        echo 'Loading Snapshot: "${snap_date_trim}" "${snap_dir_name_trim}"'
+        echo 'Loading Kernel: "${k}" ...'
+        linux \"${boot_dir_root_grub}/"${k}"\" root="${LINUX_ROOT_DEVICE}" ${kernel_parameters} ${rootflags}subvol=\""${snap_dir_name_trim}"\""
+                    if [[ "${name_microcode}" != "x" ]] ; then
+                        entry "\
+        echo 'Loading Microcode: "${u}" ...'
+        initrd \"${boot_dir_root_grub}/"${u}"\""
+                    fi
+                    entry "    }"
+                    count_warning_menuentries=$((1+count_warning_menuentries))
+                done
+            fi
+        done
+    done
+    entry  "}"
+}
+
+## Trim a string from leading and trailing whitespaces
+trim() {
+    local var="$*"
+    var="${var#"${var%%[![:space:]]*}"}"
+    var="${var%"${var##*[![:space:]]}"}"
+    echo -n "$var"
+}
+
+## List of snapshots on filesystem
+snapshot_list()
+{
+    local snapper_info="info.xml"
+    local timeshift_info="info.json"
+    local date_snapshots=()
+    local path_snapshots=()
+    local type_snapshots=()
+    local description_snapshots=()
+    IFS=$'\n'
+    for snap in $(btrfs subvolume list -sa "${btrfs_subvolume_sort}" /); do # Parse btrfs snapshots
+        IFS=$oldIFS
+        snap=($snap)
+        local path_snapshot=${snap[@]:13:${#snap[@]}}
+        if [ "$path_snapshot" = "DELETED" ]; then continue; fi # Discard deleted snapshots
+        [[ ${path_snapshot%%"/"*} == "<FS_TREE>" ]] && path_snapshot=${path_snapshot#*"/"} # Remove the "<FS_TREE>" string at the beginning of the path
+
+        # ignore specific path during run "grub-mkconfig"
+        if [ -n "${GRUB_BTRFS_IGNORE_SPECIFIC_PATH}" ] ; then
+            for isp in "${GRUB_BTRFS_IGNORE_SPECIFIC_PATH[@]}" ; do
+                [[ "${path_snapshot}" == "${isp}" ]] && continue 2;
+            done
+        fi
+        if [ -n "${GRUB_BTRFS_IGNORE_PREFIX_PATH}" ] ; then
+            for isp in "${GRUB_BTRFS_IGNORE_PREFIX_PATH[@]}" ; do
+                [[ "${path_snapshot}" == "${isp}"/* ]] && continue 2;
+            done
+        fi
+        [[ ! -d "$grub_btrfs_mount_point/$path_snapshot/boot" ]] && continue; # Discard snapshots without /boot folder
+
+        # Parse Snapper & timeshift informations
+        local type_snapshot="N/A"
+        local description_snapshot="N/A"
+        if [[ -s "$grub_btrfs_mount_point/${path_snapshot%"/"*}/$snapper_info" ]] ; then
+            type_snapshot=$(awk -F"<|>" 'match($2, /^type/) {print $3}' "$grub_btrfs_mount_point/${path_snapshot%"/"*}/$snapper_info") # search matching string beginning "type"
+            description_snapshot=$(awk -F"<|>" 'match($2, /^description/) {print $3}' "$grub_btrfs_mount_point/${path_snapshot%"/"*}/$snapper_info") # search matching string beginning "description"
+        elif [[ -s "$grub_btrfs_mount_point/${path_snapshot%"/"*}/$timeshift_info" ]] ; then
+            type_snapshot=$(awk -F" : " 'match($1, /^[ \t]+"tags"/) {gsub(/"|,/,"");print $2}' "$grub_btrfs_mount_point/${path_snapshot%"/"*}/$timeshift_info") # search matching string beginning "tags"
+            description_snapshot=$(awk -F" : " 'match($1, /^[ \t]+"comments"/) {gsub(/"|,/,"");print $2}' "$grub_btrfs_mount_point/${path_snapshot%"/"*}/$timeshift_info") # search matching string beginning "comments"
+        fi
+        [[ -z "$type_snapshot" ]] && type_snapshot=("N/A")
+        [[ -z "$description_snapshot" ]] && description_snapshot=("N/A")
+
+        # ignore specific {type,tag,description} of snapshot during run "grub-mkconfig"
+        if [ -n "${GRUB_BTRFS_IGNORE_SNAPSHOT_TYPE}" ] ; then
+            for ist in "${GRUB_BTRFS_IGNORE_SNAPSHOT_TYPE[@]}" ; do
+                [[ "${type_snapshot}" == "${ist}" ]] && continue 2;
+            done
+        fi
+        if [ -n "${GRUB_BTRFS_IGNORE_SNAPSHOT_DESCRIPTION}" ] ; then
+            for isd in "${GRUB_BTRFS_IGNORE_SNAPSHOT_DESCRIPTION[@]}" ; do
+                [[ "${description_snapshot}" == "${isd}" ]] && continue 2;
+            done
+        fi
+
+        local date_snapshot="${snap[@]:10:2}"
+        date_snapshots+=("$date_snapshot")
+        path_snapshots+=("$path_snapshot")
+        type_snapshots+=("$type_snapshot")
+        description_snapshots+=("$description_snapshot")
+    done
+
+    # Find max length of a snapshot date, needed for pretty formatting
+    local max_date_length=0
+    for i in "${date_snapshots[@]}"; do
+        local length="${#i}"
+        [[ "$length" -gt "$max_date_length" ]] && max_date_length=$length
+    done
+
+    # Find max length of a snapshot name, needed for pretty formatting
+    local max_path_length=0
+    for i in "${path_snapshots[@]}"; do
+        local length="${#i}"
+        [[ "$length" -gt "$max_path_length" ]] && max_path_length=$length
+    done
+
+    # Find max length of a snapshot type, needed for pretty formatting
+    local max_type_length=0
+    for i in "${type_snapshots[@]}"; do
+        local length="${#i}"
+        [[ "$length" -gt "$max_type_length" ]] && max_type_length=$length
+    done
+
+    # Find max length of a snapshot description, needed for pretty formatting
+    local max_description_length=0
+    for i in "${description_snapshots[@]}"; do
+        local length="${#i}"
+        [[ "$length" -gt "$max_description_length" ]] && max_description_length=$length
+    done
+
+    for i in "${!path_snapshots[@]}"; do
+        printf -v entry "%-${max_date_length}s | %-${max_path_length}s | %-${max_type_length}s | %-${max_description_length}s |" "${date_snapshots[$i]}" "${path_snapshots[$i]}" "${type_snapshots[$i]}" "${description_snapshots[$i]}"
+        echo "$entry"
+    done
+
+    IFS=$oldIFS
+}
+
+## Parse snapshots in snapshot_list
+parse_snapshot_list()
+{
+    snap_date=" $(echo "$item" | cut -d'|' -f1)" # column_1, first space is necessary for pretty formatting
+    snap_date_trim="$(trim "$snap_date")"
+
+    snap_dir_name="$(echo "$item" | cut -d'|' -f2)" # column_2
+    snap_dir_name_trim="$(trim "$snap_dir_name")"
+    snap_snapshot="$snap_dir_name" # Used by "title_format" function
+
+    snap_type="$(echo "$item" | cut -d'|' -f3)" # column_3
+
+    snap_description="$(echo "$item" | cut -d'|' -f4)" # column_4
+}
+
+## Detect kernels in "boot_directory"
+detect_kernel()
+{
+    list_kernel=()
+    # Original kernel (auto-detect)
+    for okernel in  "${boot_dir}"/vmlinuz-* \
+                    "${boot_dir}"/vmlinux-* \
+                    "${boot_dir}"/kernel-* ; do
+        [[ ! -f "${okernel}" ]] && continue;
+        list_kernel+=("$okernel")
+    done
+
+    # Custom name kernel in "GRUB_BTRFS_NKERNEL"
+    if [ -n "${GRUB_BTRFS_NKERNEL}" ] ; then
+        for ckernel in "${boot_dir}/${GRUB_BTRFS_NKERNEL[@]}" ; do
+            [[ ! -f "${ckernel}" ]] && continue;
+            list_kernel+=("$ckernel")
+        done
+    fi
+}
+
+## Detect initramfs in "boot_directory"
+detect_initramfs()
+{
+    list_initramfs=()
+    # Original initramfs (auto-detect)
+    for oinitramfs in   "${boot_dir}"/initrd.img-* \
+                        "${boot_dir}"/initramfs-* \
+                        "${boot_dir}"/initrd-* ; do
+        [[ ! -f "${oinitramfs}" ]] && continue;
+        list_initramfs+=("$oinitramfs")
+    done
+
+    # Custom name initramfs in "GRUB_BTRFS_NINIT"
+    if [ -n "${GRUB_BTRFS_NINIT}" ] ; then
+        for cinitramfs in "${boot_dir}/${GRUB_BTRFS_NINIT[@]}" ; do
+            [[ ! -f "${cinitramfs}" ]] && continue;
+            list_initramfs+=("$cinitramfs")
+        done
+    fi
+    if [ -z "${list_initramfs}" ]; then list_initramfs=(x); fi
+}
+
+## Detect microcode in "boot_directory"
+detect_microcode()
+{
+    list_ucode=()
+    # Original intel/amd microcode (auto-detect)
+    # See "https://www.gnu.org/software/grub/manual/grub/html_node/Simple-configuration.html"
+    for oiucode in  "${boot_dir}"/intel-uc.img \
+                    "${boot_dir}"/intel-ucode.img \
+                    "${boot_dir}"/amd-uc.img \
+                    "${boot_dir}"/amd-ucode.img \
+                    "${boot_dir}"/early_ucode.cpio \
+                    "${boot_dir}"/microcode.cpio; do
+        [[ ! -f "${oiucode}" ]] && continue;
+        list_ucode+=("$oiucode")
+    done
+
+    # Custom name microcode in "GRUB_BTRFS_CUSTOM_MICROCODE"
+    if [ -n "${GRUB_BTRFS_CUSTOM_MICROCODE}" ] ; then
+        for cucode in "${boot_dir}/${GRUB_BTRFS_CUSTOM_MICROCODE[@]}" ; do
+            [[ ! -f "${cucode}" ]] && continue
+            list_ucode+=("$cucode")
+        done
+    fi
+    if [ -z "${list_ucode}" ]; then list_ucode=(x); fi
+}
+
+## Title format in Grub-menu
+declare -A title_column=( [date]=Date [snapshot]=Snapshot [type]=Type [description]=Description ) # Column title that appears in the header
+title_format()
+{
+    title_menu="|" # "|" is for visuals only
+    title_submenu="|" # "|" is for visuals only
+    [[ -z "${GRUB_BTRFS_TITLE_FORMAT}" ]] && GRUB_BTRFS_TITLE_FORMAT=("date" "snapshot" "type" "description"); # Default parameters
+    for key in "${!GRUB_BTRFS_TITLE_FORMAT[@]}"; do
+            [[ ${GRUB_BTRFS_TITLE_FORMAT[$key],,} != "${title_column[${GRUB_BTRFS_TITLE_FORMAT[$key]}],,}" ]] && continue; # User used wrong parameter
+            declare -n var="snap_${GRUB_BTRFS_TITLE_FORMAT[$key],,}" # $var is a indirect variable
+            if [[ "${#var}" -lt "${#title_column[${GRUB_BTRFS_TITLE_FORMAT[$key],,}]}" ]]; then # Add extra spaces if length of $var is smaller than the length of column, needed for pretty formatting
+                printf -v var "%-$(((${#title_column[${GRUB_BTRFS_TITLE_FORMAT[$key],,}]}-${#var})+${#var}))s" "${var}";
+            fi
+            title_menu+="${var}|"
+            title_submenu+=" $(trim "${var}") |"
+    done
+}
+# Adds a header to the grub-btrfs.cfg file
+header_menu()
+{
+    local header_entry=""
+    [[ -z "${GRUB_BTRFS_TITLE_FORMAT}" ]] && GRUB_BTRFS_TITLE_FORMAT=("date" "snapshot" "type" "description"); # Default parameters
+        for key in "${!GRUB_BTRFS_TITLE_FORMAT[@]}"; do
+            [[ ${GRUB_BTRFS_TITLE_FORMAT[$key],,} != "${title_column[${GRUB_BTRFS_TITLE_FORMAT[$key]}],,}" ]] && continue; # User used wrong parameter
+            declare -n var="snap_${GRUB_BTRFS_TITLE_FORMAT[$key],,}" # $var is a indirect variable
+            # Center alignment, needed for pretty formatting
+            local lenght_title_column_left=$((${#var}-${#title_column[${GRUB_BTRFS_TITLE_FORMAT[$key],,}]}))
+            ((lenght_title_column_left%2)) && lenght_title_column_left=$((lenght_title_column_left+1));  # If the difference is an odd number, add an extra space
+            lenght_title_column_left=$((((lenght_title_column_left/2)+${#title_column[${GRUB_BTRFS_TITLE_FORMAT[$key],,}]})));
+            local lenght_title_column_right=$(((${#var}-lenght_title_column_left)+1)) #+1 is necessary for extra "|" character
+            header_entry+=$(printf "%${lenght_title_column_left}s%${lenght_title_column_right}s" "${title_column[${GRUB_BTRFS_TITLE_FORMAT[$key],,}]}" "|") # Final "|" is for visuals only
+        done
+    sed -i "1imenuentry '|${header_entry}' { echo }" "$grub_directory/grub-btrfs.new" # First "|" is for visuals only
+}
+
+## List of kernels, initramfs and microcode in snapshots
+boot_bounded()
+{
+    # Initialize menu entries
+    IFS=$'\n'
+    for item in $(snapshot_list); do
+        [[ ${limit_snap_show} -le 0 ]] && break; # fix: limit_snap_show=0
+        IFS=$oldIFS
+        parse_snapshot_list
+        boot_dir="$grub_btrfs_mount_point/$snap_dir_name_trim$boot_directory"
+        detect_kernel
+        if [ -z "${list_kernel}" ]; then continue; fi
+        name_kernel=("${list_kernel[@]##*"/"}")
+        detect_initramfs
+        name_initramfs=("${list_initramfs[@]##*"/"}")
+        detect_microcode
+        name_microcode=("${list_ucode[@]##*"/"}")
+        detect_rootflags
+        title_format
+        boot_dir_root_grub="$(make_system_path_relative_to_its_root "${boot_dir}")" # convert "boot_directory" to root of GRUB (e.g /boot become /)
+        make_menu_entries
+        # show snapshot found during run "grub-mkconfig"
+        if [[ "${GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND:-"true"}" = "true" ]]; then
+            printf "Found snapshot: %s\n" "$item" >&2 ;
+        fi
+        # Limit snapshots found during run "grub-mkconfig"
+        count_limit_snap=$((1+count_limit_snap))
+        [[ $count_limit_snap -ge $limit_snap_show ]] && break;
+    done
+    IFS=$oldIFS
+}
+
+boot_separate()
+{
+    boot_dir="${boot_directory}"
+    boot_dir_root_grub="$(make_system_path_relative_to_its_root "${boot_dir}")" # convert "boot_directory" to root of GRUB (e.g /boot become /)
+    detect_kernel
+    if [ -z "${list_kernel}" ]; then print_error "Kernels not found."; fi
+    name_kernel=("${list_kernel[@]##*"/"}")
+    detect_initramfs
+    name_initramfs=("${list_initramfs[@]##*"/"}")
+    detect_microcode
+    name_microcode=("${list_ucode[@]##*"/"}")
+
+    # Initialize menu entries
+    IFS=$'\n'
+    for item in $(snapshot_list); do
+        [[ ${limit_snap_show} -le 0 ]] && break; # fix: limit_snap_show=0
+        IFS=$oldIFS
+        parse_snapshot_list
+        detect_rootflags
+        title_format
+        make_menu_entries
+        # show snapshot found during run "grub-mkconfig"
+        if [[ "${GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND:-"true"}" = "true" ]]; then
+            printf "Found snapshot: %s\n" "$item" >&2 ;
+        fi
+        # Limit snapshots found during run "grub-mkconfig"
+        count_limit_snap=$((1+count_limit_snap))
+        [[ $count_limit_snap -ge $limit_snap_show ]] && break;
+    done
+    IFS=$oldIFS
+}
+
+rm -f "$grub_directory/grub-btrfs.new"
+> "$grub_directory/grub-btrfs.new" # Create a "grub-btrfs.new" file in "grub_directory"
+# Create mount point then mounting
+[[ ! -d $grub_btrfs_mount_point ]] && mkdir -p "$grub_btrfs_mount_point"
+mount -o ro,subvolid=5 /dev/disk/by-uuid/"$root_uuid" "$grub_btrfs_mount_point/"
+trap "unmount_grub_btrfs_mount_point" EXIT # unmounting mount point on EXIT signal
+count_warning_menuentries=0 # Count menuentries
+count_limit_snap=0 # Count snapshots
+check_uuid_required
+# Detects if /boot is a separate partition
+[[ "${GRUB_BTRFS_OVERRIDE_BOOT_PARTITION_DETECTION,,}" == "true" ]] && printf "Override boot partition detection : enable \n" >&2 && boot_separate;
+if [[ "$root_uuid" != "$boot_uuid" ]] || [[ "$root_uuid_subvolume" != "$boot_uuid_subvolume" ]]; then boot_separate ; else boot_bounded ; fi
+# Show warn, menuentries exceeds 250 entries
+[[ $count_warning_menuentries -ge 250 ]] && printf "Generated %s total GRUB entries. You might experience issues loading snapshots menu in GRUB.\n" "${count_warning_menuentries}" >&2 ;
+# Show total found snapshots
+if [[ "${GRUB_BTRFS_SHOW_TOTAL_SNAPSHOTS_FOUND:-"true"}" = "true" && -n "${count_limit_snap}" && "${count_limit_snap}" != "0" ]]; then
+    printf "Found %s snapshot(s)\n" "${count_limit_snap}" >&2 ;
+fi
+# if no snapshot found, exit
+if [[ "${count_limit_snap}" = "0" || -z "${count_limit_snap}" ]]; then
+    print_error "No snapshots found."
+fi
+# Make a submenu in GRUB (grub.cfg) and move "grub-btrfs.new" to "grub-btrfs.cfg"
+header_menu
+if "${bindir}/${GRUB_BTRFS_SCRIPT_CHECK:-grub-script-check}" "$grub_directory/grub-btrfs.new"; then
+    cat "$grub_directory/grub-btrfs.new" > "$grub_directory/grub-btrfs.cfg"
+    rm -f "$grub_directory/grub-btrfs.new"
+    cat << EOF
+submenu '${submenuname}' ${protection_authorized_users}${unrestricted_access_submenu}{
+    configfile "\${prefix}/grub-btrfs.cfg"
+}
+EOF
+else
+    print_error "Syntax errors are detected in generated grub-btrfs.cfg file."
+fi
--- a/86
+++ b/86
@@ -0,0 +1,86 @@
+PKGNAME ?= grub-btrfs
+PREFIX ?= /usr
+
+INITCPIO ?= false
+SYSTEMD ?= true
+OPENRC ?= false
+
+SHARE_DIR = $(DESTDIR)$(PREFIX)/share
+LIB_DIR = $(DESTDIR)$(PREFIX)/lib
+BIN_DIR = $(DESTDIR)$(PREFIX)/bin
+
+.PHONY: install uninstall help
+
+install:
+	@if test "$(shell id -u)" != 0; then \
+		echo "You are not root, run this target as root please."; \
+		exit 1; \
+	fi
+	@install -Dm755 -t "$(DESTDIR)/etc/grub.d/" 41_snapshots-btrfs
+	@install -Dm644 -t "$(DESTDIR)/etc/default/grub-btrfs/" config
+	@# Systemd init system
+	@if test "$(SYSTEMD)" = true; then \
+		install -Dm644 -t "$(LIB_DIR)/systemd/system/" grub-btrfs.path; \
+		install -Dm644 -t "$(LIB_DIR)/systemd/system/" grub-btrfs.service; \
+	 fi
+	@# OpenRC init system
+	@if test "$(OPENRC)" = true; then \
+		install -Dm744 -t "$(BIN_DIR)/" grub-btrfs-openrc; \
+		install -Dm744 -t "$(DESTDIR)/etc/init.d/" grub-btrfsd; \
+	 fi
+	@# Arch Linux like distros only :
+	@if test "$(INITCPIO)" = true; then \
+		install -Dm644 "initramfs/Arch Linux/overlay_snap_ro-install" "$(LIB_DIR)/initcpio/install/grub-btrfs-overlayfs"; \
+		install -Dm644 "initramfs/Arch Linux/overlay_snap_ro-hook" "$(LIB_DIR)/initcpio/hooks/grub-btrfs-overlayfs"; \
+	 fi
+	@install -Dm644 -t "$(SHARE_DIR)/licenses/$(PKGNAME)/" LICENSE
+	@install -Dm644 -t "$(SHARE_DIR)/doc/$(PKGNAME)/" README.md
+	@install -Dm644 "initramfs/readme.md" "$(SHARE_DIR)/doc/$(PKGNAME)/initramfs-overlayfs.md"
+
+uninstall:
+	@if test "$(shell id -u)" != 0; then \
+		echo "You are not root, run this target as root please."; \
+		exit 1; \
+	fi
+	@grub_dirname="$$(grep -oP '^[[:space:]]*GRUB_BTRFS_GRUB_DIRNAME=\K.*' "$(DESTDIR)/etc/default/grub-btrfs/config" | sed "s|\s*#.*||;s|(\s*\(.\+\)\s*)|\1|;s|['\"]||g")"; \
+	 rm -f "$${grub_dirname:-/boot/grub}/grub-btrfs.cfg"
+	@rm -f "$(DESTDIR)/etc/default/grub-btrfs/config"
+	@rm -f "$(DESTDIR)/etc/grub.d/41_snapshots-btrfs"
+	@rm -f "$(LIB_DIR)/systemd/system/grub-btrfs.path"
+	@rm -f "$(LIB_DIR)/systemd/system/grub-btrfs.service"
+	@rm -f "$(BIN_DIR)/grub-btrfs-openrc;"
+	@rm -f "$(DESTDIR)/etc/init.d/grub-btrfsd;"
+	@rm -f "$(LIB_DIR)/initcpio/install/grub-btrfs-overlayfs"
+	@rm -f "$(LIB_DIR)/initcpio/hooks/grub-btrfs-overlayfs"
+	@# Arch Linux UNlike distros only :
+	@if test "$(INITCPIO)" != true && test -d "$(LIB_DIR)/initcpio"; then \
+		rmdir --ignore-fail-on-non-empty "$(LIB_DIR)/initcpio/install" || :; \
+		rmdir --ignore-fail-on-non-empty "$(LIB_DIR)/initcpio/hooks" || :; \
+		rmdir --ignore-fail-on-non-empty "$(LIB_DIR)/initcpio" || :; \
+	 fi
+	@rm -f "$(SHARE_DIR)/doc/$(PKGNAME)/README.md"
+	@rm -f "$(SHARE_DIR)/doc/$(PKGNAME)/initramfs-overlayfs.md"
+	@rm -f "$(SHARE_DIR)/licenses/$(PKGNAME)/LICENSE"
+	@rmdir --ignore-fail-on-non-empty "$(SHARE_DIR)/doc/$(PKGNAME)/" || :
+	@rmdir --ignore-fail-on-non-empty "$(SHARE_DIR)/licenses/$(PKGNAME)/" || :
+	@rmdir --ignore-fail-on-non-empty "$(DESTDIR)/etc/default/grub-btrfs" || :
+
+help:
+	@echo
+	@echo "Usage: $(MAKE) [ <parameter>=<value> ... ] [ <action> ]"
+	@echo
+	@echo "  actions: install"
+	@echo "           uninstall"
+	@echo "           help"
+	@echo
+	@echo "  parameter | type | description                    | defaults"
+	@echo "  ----------+------+--------------------------------+----------------------------"
+	@echo "  DESTDIR   | path | install destination            | <unset>"
+	@echo "  PREFIX    | path | system tree prefix             | '/usr'"
+	@echo "  SHARE_DIR | path | shared data location           | '\$$(DESTDIR)\$$(PREFIX)/share'"
+	@echo "  LIB_DIR   | path | system libraries location      | '\$$(DESTDIR)\$$(PREFIX)/lib'"
+	@echo "  PKGNAME   | name | name of the ditributed package | 'grub-btrfs'"
+	@echo "  INITCPIO  | bool | include mkinitcpio hook        | false"
+	@echo "  SYSTEMD   | bool | include unit files             | true"
+	@echo "  OPENRC    | bool | include OpenRc daemon          | false"
+	@echo
--- a/README.md
+++ b/README.md
@@ -1,4 +1,156 @@
-grub-btrfs
-==========
+[![GitHub release](https://img.shields.io/github/release/Antynea/grub-btrfs.svg)](https://github.com/Antynea/grub-btrfs/releases)
+![](https://img.shields.io/github/license/Antynea/grub-btrfs.svg)

-grub-btrfs, add support for btrfs snapshots into grub menu
+## grub-btrfs 
+
+This is a version 4.xx of grub-btrfs
+##### BTC donation address: `1Lbvz244WA8xbpHek9W2Y12cakM6rDe5Rt`
+- - -
+### Description :
+Improves Grub by adding "btrfs snapshots" to the Grub menu.
+
+You can boot your system on a "snapshot" from the Grub menu.  
+Supports manual snapshots, snapper, timeshift ...
+
+##### Warning: booting on read-only snapshots can be tricky
+
+If you choose to do it, `/var/log` or even `/var` must be on a separate subvolume.  
+Otherwise, make sure your snapshots are writeable.  
+See [this ticket](https://github.com/Antynea/grub-btrfs/issues/92) for more info.
+
+This project includes its own solution.  
+* Refer to the [documentation](https://github.com/Antynea/grub-btrfs/blob/master/initramfs/readme.md).  
+* Or used `GRUB_BTRFS_SYSTEMD_VOLATILE=true` in config file. (experimental, See [config file](https://github.com/Antynea/grub-btrfs/blob/master/config) for more information.)
+- - -
+### What does grub-btrfs v4.xx do :
+* Automatically List snapshots existing on root partition (btrfs).
+* Automatically Detect if "/boot" is in separate partition.
+* Automatically Detect kernel, initramfs and intel/amd microcode in "/boot" directory on snapshots.
+* Automatically Create corresponding "menuentry" in `grub.cfg`
+* Automatically detect the type/tags and descriptions/comments of snapper/timeshift snapshots.
+* Automatically generate `grub.cfg` if you use the provided systemd service.
+
+- - -
+### Installation :
+#### Arch Linux
+The package is available in the community repository [grub-btrfs](https://archlinux.org/packages/community/any/grub-btrfs/)
+```
+pacman -S grub-btrfs
+```
+
+#### Gentoo
+grub-btrfs is only available in the Gentoo User Repository (GURU) and not in the official Gentoo repository.  
+If you have not activated the GURU yet, do so by running:
+```
+emerge -av app-eselect/eselect-repository 
+eselect repository enable guru 
+emerge --sync 
+```
+
+Now merge grub-btrfs via 
+`emerge app-backup/grub-btrfs`
+
+#### Manual
+* Run `make install` or look into Makefile for instructions on where to put each file.
+* Run `make help` to check what options are available.
+* Dependencies:
+  * [btrfs-progs](https://archlinux.org/packages/core/x86_64/btrfs-progs/)
+  * [grub](https://archlinux.org/packages/core/x86_64/grub/)
+  * [bash >4](https://archlinux.org/packages/core/x86_64/bash/)
+  * [gawk ](https://archlinux.org/packages/core/x86_64/gawk/)
+  * [strings](https://archlinux.org/packages/core/x86_64/binutils/)
+
+#### NOTE: All distros
+Generate your Grub menu after installation for the changes to take effect.  
+For example:  
+On **Arch Linux** or **Gentoo** use `grub-mkconfig -o /boot/grub/grub.cfg`.  
+On **Fedora** use `grub2-mkconfig -o /boot/grub2/grub.cfg`  
+On **Debian-like** distribution `update-grub` is an alias to `grub-mkconfig ...`
+- - -
+### Customization :
+
+You have the possibility to modify many parameters in `/etc/default/grub-btrfs/config`.  
+See [config file](https://github.com/Antynea/grub-btrfs/blob/master/config) for more information.
+
+- - -
+### Automatically update grub :
+#### Systemd
+1. If you would like grub-btrfs menu to automatically update when a snapshot is created or deleted:
+* Use `systemctl enable grub-btrfs.path`.
+  * `grub-btrfs.path` automatically (re)generates `grub-btrfs.cfg` when a modification appears in `/.snapshots` mount point (by default).
+  * If the `/.snapshots` mount point is already mounted, then use `systemctl start grub-btrfs.path` to start monitoring.  
+    Otherwise, the unit will automatically start monitoring when the mount point will be available.
+* If your snapshots location aren't mounted in `/.snapshots`, you must modify `grub-btrfs.path` unit using  
+`systemctl edit --full grub-btrfs.path` and run `systemctl reenable grub-btrfs.path` for changes take effect.  
+To find out the name of the `.mount` unit  
+use `systemctl list-units -t mount`.  
+	* For example: Timeshift mounts its snapshot folder in `/run/timeshift/backup/timeshift-btrfs/snapshots`.
+
+		Use `systemctl edit --full grub-btrfs.path`.
+		Then replace the whole block by:
+		```
+		[Unit]
+		Description=Monitors for new snapshots
+		DefaultDependencies=no
+		Requires=run-timeshift-backup.mount
+		After=run-timeshift-backup.mount
+		BindsTo=run-timeshift-backup.mount
+
+		[Path]
+		PathModified=/run/timeshift/backup/timeshift-btrfs/snapshots
+
+		[Install]
+		WantedBy=run-timeshift-backup.mount
+		```
+		Then save and finally run `systemctl reenable grub-btrfs.path` for changes take effect.  
+		Optional:  
+		If the `/run/timeshift/backup/timeshift-btrfs/snapshots` mount point is already mounted,  
+		then use `systemctl start grub-btrfs.path` to start monitoring.  
+		Otherwise, the unit will automatically start monitoring when the mount point will be available.  
+	* You can view your change to `systemctl cat grub-btrfs.path`.
+	* To revert change use `systemctl revert grub-btrfs.path`.
+
+2. If you would like grub-btrfs menu to automatically update on system restart/ shutdown:  
+[Look at this comment](https://github.com/Antynea/grub-btrfs/issues/138#issuecomment-766918328)  
+Currently not implemented
+##
+#### OpenRC
+1. If you would like grub-btrfs menu to automatically update when a snapshot is created or deleted:
+* Use `rc-config add grub-btrfsd default`, to start the grub-btrfsd daemon the next time the system boots. 
+	* To start `grub-btrfsd` right now, run `rc-service grub-btrfsd start`
+	* `grub-btrfsd` automatically watches the snapshot directory of timeshift (/run/timeshift/backup/timeshift-btrfs/snapshots)
+	and updates the grub-menu when a change occurs.
+* Currently untested for snapper
+
+2. If you would like grub-btrfs menu to automatically update on system restart/ shutdown:
+Just add the following script as `/etc/local.d/grub-btrfs-update.stop`
+	```
+	#!/bin/bash
+	
+	description="Update the grub btrfs snapshots menu"
+	name="grub-btrfs-update"
+	
+	depend()
+	{
+	  use localmount
+	}
+	
+	bash -c 'if [ -s "${GRUB_BTRFS_GRUB_DIRNAME:-/boot/grub}/grub-btrfs.cfg" ]; then /etc/grub.d/41_snapshots-btrfs; else {GRUB_BTRFS_MKCONFIG:-grub-mkconfig} -o {GRUB_BTRFS_GRUB_DIRNAME:-/boot/grub}/grub.cfg; fi' 
+	```
+	
+	Make your script executeable with `chmod a+x /etc/local.d/grub-btrfs-update.stop`.
+
+* The extension ".stop" at the end of the filename indicates to locald that this script should be run at shutdown. 
+ If you want to run the menu update on startup instead, rename the file to `grub-btrfs-update.start`
+* Works for snapper and timeshift
+
+##### Warning :
+by default, `grub-mkconfig` command is used.  
+Might be `grub2-mkconfig` on some systems (Fedora ...).   
+Edit `GRUB_BTRFS_MKCONFIG` variable in `/etc/default/grub-btrfs/config` file to reflect this.
+- - -
+### Special thanks for assistance and contributions
+* [Maxim Baz](https://github.com/maximbaz)
+* [Schievel1](https://github.com/Antynea/grub-btrfs/discussions/173#discussioncomment-1438790)
+* [All contributors](https://github.com/Antynea/grub-btrfs/graphs/contributors)
+- - -
--- a/142
+++ b/142
@@ -0,0 +1,142 @@
+#!/usr/bin/env bash
+
+# Disable grub-btrfs.
+# Default: "false"
+#GRUB_BTRFS_DISABLE="true"
+
+# Name appearing in the Grub menu.
+# Default: "Use distribution information from /etc/os-release."
+#GRUB_BTRFS_SUBMENUNAME="Arch Linux snapshots"
+
+# Custom title.
+# Shows/Hides "date" "snapshot" "type" "description" in the Grub menu, custom order available.
+# Default: ("date" "snapshot" "type" "description")
+#GRUB_BTRFS_TITLE_FORMAT=("date" "snapshot" "type" "description")
+
+# Limit the number of snapshots populated in the GRUB menu.
+# Default: "50"
+#GRUB_BTRFS_LIMIT="50"
+
+# Sort the found subvolumes by "ogeneration" or "generation" or "path" or "rootid".
+# # See Sorting section to https://btrfs.wiki.kernel.org/index.php/Manpage/btrfs-subvolume#SUBCOMMAND
+# "-rootid" means list snapshot by new ones first.
+# Default: "-rootid"
+#GRUB_BTRFS_SUBVOLUME_SORT="+ogen,-gen,path,rootid"
+
+# Show snapshots found during run "grub-mkconfig"
+# Default: "true"
+#GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND="false"
+
+# Show Total of snapshots found during run "grub-mkconfig"
+# Default: "true"
+#GRUB_BTRFS_SHOW_TOTAL_SNAPSHOTS_FOUND="true"
+
+# By default, "grub-btrfs" automatically detects most existing kernels.
+# If you have one or more custom kernels, you can add them here.
+# Default: ("")
+#GRUB_BTRFS_NKERNEL=("kernel-custom" "vmlinux-custom")
+
+# By default, "grub-btrfs" automatically detects most existing initramfs.
+# If you have one or more custom initramfs, you can add them here.
+# Default: ("")
+#GRUB_BTRFS_NINIT=("initramfs-custom.img" "initrd-custom.img" "otherinit-custom.gz")
+
+# By default, "grub-btrfs" automatically detects most existing microcodes.
+# If you have one or more custom microcodes, you can add them here.
+# Default: ("")
+#GRUB_BTRFS_CUSTOM_MICROCODE=("custom-ucode.img" "custom-uc.img "custom_ucode.cpio")
+
+# Comma seperated mount options to be used when booting a snapshot.
+# They can be defined here as well as in the "/" line inside the respective snapshots'
+# "/etc/fstab" files.  Mount options found in both places are combined, and this variable
+# takes priority over `fstab` entries.
+# NB: Do NOT include "subvol=..." or "subvolid=..." here.
+# Default: ""
+#GRUB_BTRFS_ROOTFLAGS="space_cache,commit=10,norecovery"
+
+# Booting on read-only snapshots can be tricky. (See https://github.com/Antynea/grub-btrfs#warning-booting-on-read-only-snapshots-can-be-tricky)
+# Based on several reports, "/var" must be writable to start properly.
+# Systemd can do this for you. (not compatible with OpenRC)
+# The snapshot will boot in read-only mode but "/var" will be writable using a "tmpfs" mount point (which means, folder mounted in RAM)
+# This should make it easier to rollback.
+# Note to all: Detecting "systemd" as the default init on the snapshot is automatic, if don't, file a bug report at https://github.com/Antynea/grub-btrfs.
+# Note to Arch Linux users: If you use the "grub-btrfs-overlayfs" option on Arch Linux, "GRUB_BTRFS_SYSTEMD_VOLATILE" will do nothing.
+# Default: "false"
+#GRUB_BTRFS_SYSTEMD_VOLATILE=true
+
+# Ignore specific path during run "grub-mkconfig".
+# Only exact paths are ignored.
+# e.g : if `specific path` = @, only `@` snapshot will be ignored.
+# Default: ("@")
+GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("@")
+
+# Ignore prefix path during run "grub-mkconfig".
+# Any path starting with the specified string will be ignored.
+# e.g : if `prefix path` = @, all snapshots beginning with "@/..." will be ignored.
+# Default: ("var/lib/docker" "@var/lib/docker" "@/var/lib/docker")
+GRUB_BTRFS_IGNORE_PREFIX_PATH=("var/lib/docker" "@var/lib/docker" "@/var/lib/docker")
+
+# Ignore specific type/tag of snapshot during run "grub-mkconfig".
+# For snapper:
+# Type = single, pre, post.
+# For Timeshift:
+# Tag = boot, ondemand, hourly, daily, weekly, monthly.
+# Default: ("")
+#GRUB_BTRFS_IGNORE_SNAPSHOT_TYPE=("")
+
+# Ignore specific description of snapshot during run "grub-mkconfig".
+# e.g: timeline
+# Default: ("")
+#GRUB_BTRFS_IGNORE_SNAPSHOT_DESCRIPTION=("")
+
+# By default "grub-btrfs" automatically detects your boot partition,
+# either located at the system root or on a separate partition or in a subvolume,
+# Change to "true" if your boot partition isn't detected as separate.
+# Default: "false"
+#GRUB_BTRFS_OVERRIDE_BOOT_PARTITION_DETECTION="true"
+
+# Location of the folder containing the "grub.cfg" file.
+# Use by grub-btrfs to save the file "grub-btrfs.cfg".
+# Might be grub2 on some systems.
+# For example, on Fedora with EFI : "/boot/efi/EFI/fedora"
+# Default: "/boot/grub"
+#GRUB_BTRFS_GRUB_DIRNAME="/boot/grub2"
+
+# Location of kernels/initramfs/microcode.
+# Use by "grub-btrfs" to detect the boot partition and the location of kernels/initrafms/microcodes.
+# Default: "/boot"
+#GRUB_BTRFS_BOOT_DIRNAME="/boot"
+
+# Name/path of grub-mkconfig command, use by "grub-btrfs.service"
+# Might be 'grub2-mkconfig' on some systems (Fedora ...)
+# Default paths are /sbin:/bin:/usr/sbin:/usr/bin,
+# if your path is missing, report it on the upstream project.
+# For example, on Fedora : "/sbin/grub2-mkconfig"
+# You can use only name or full path.
+# Default: grub-mkconfig
+#GRUB_BTRFS_MKCONFIG=/usr/bin/grub2-mkconfig
+
+# Name of grub-script-check command, use by "grub-btrfs"
+# Might be 'grub2-script-check' on some systems (Fedora ...)
+# For example, on Fedora : "grub2-script-check"
+# Default: grub-script-check
+#GRUB_BTRFS_SCRIPT_CHECK=grub2-script-check
+
+# Path of grub-mkconfig_lib file, use by "grub-btrfs"
+# Might be '/usr/share/grub2/grub-mkconfig_lib' on some systems (Opensuse ...)
+# Default: /usr/share/grub/grub-mkconfig_lib
+#GRUB_BTRFS_MKCONFIG_LIB=/usr/share/grub2/grub-mkconfig_lib
+
+# Password protection management for submenu,snapshots
+# Refer to the Grub documentation https://www.gnu.org/software/grub/manual/grub/grub.html#Authentication-and-authorisation
+# and this comment https://github.com/Antynea/grub-btrfs/issues/95#issuecomment-682295660
+#
+# Add authorized usernames separate by comma (foo,bar)
+# When Grub's password protection is enabled, the superuser is authorized by default, it isn't necessary to add it
+# Default: ""
+#GRUB_BTRFS_PROTECTION_AUTHORIZED_USERS="foo,bar"
+#
+# Disable authentication support for submenu of Grub-btrfs only (--unrestricted)
+# doesn't work if GRUB_BTRFS_PROTECTION_AUTHORIZED_USERS isn't empty
+# Default: "false"
+#GRUB_BTRFS_DISABLE_PROTECTION_SUBMENU="true"
--- a/6
+++ b/6
@@ -0,0 +1,6 @@
+#!/bin/sh
+echo $$ > /run/grub-btrfsd.pid
+
+while true; do sleep 1 && inotifywait -e create -e delete /run/timeshift/backup/timeshift-btrfs/snapshots && sleep 5 && if [ -s "${GRUB_BTRFS_GRUB_DIRNAME:-/boot/grub}/grub-btrfs.cfg" ]; then /etc/grub.d/41_snapshots-btrfs; else ${GRUB_BTRFS_MKCONFIG:-grub-mkconfig} -o ${GRUB_BTRFS_GRUB_DIRNAME:-/boot/grub}/grub.cfg; fi  ; done
+
+
--- a/grub-btrfs.path
+++ b/grub-btrfs.path
@@ -0,0 +1,12 @@
+[Unit]
+Description=Monitors for new snapshots
+DefaultDependencies=no
+Requires=\x2esnapshots.mount
+After=\x2esnapshots.mount
+BindsTo=\x2esnapshots.mount
+
+[Path]
+PathModified=/.snapshots
+
+[Install]
+WantedBy=\x2esnapshots.mount
--- a/grub-btrfs.service
+++ b/grub-btrfs.service
@@ -0,0 +1,11 @@
+[Unit]
+Description=Regenerate grub-btrfs.cfg
+
+[Service]
+Type=oneshot
+# Set the possible paths for `grub-mkconfig`
+Environment="PATH=/sbin:/bin:/usr/sbin:/usr/bin"
+# Load environment variables from the configuration
+EnvironmentFile=/etc/default/grub-btrfs/config
+# Regenerate just '/boot/grub/grub-btrfs.cfg' if it exists and is not empty, else regenerate the whole grub menu
+ExecStart=bash -c 'if [ -s "${GRUB_BTRFS_GRUB_DIRNAME:-/boot/grub}/grub-btrfs.cfg" ]; then /etc/grub.d/41_snapshots-btrfs; else ${GRUB_BTRFS_MKCONFIG:-grub-mkconfig} -o ${GRUB_BTRFS_GRUB_DIRNAME:-/boot/grub}/grub.cfg; fi' 
--- a/14
+++ b/14
@@ -0,0 +1,14 @@
+#!/sbin/openrc-run
+# Copyright 1999-2021 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+
+name="grub-btrfs daemon"
+command="/usr/bin/grub-btrfs-openrc"
+pidfile="/run/{RC_SVCNAME}.pid"
+command_background=true
+
+depend() {
+   use localmount
+}
+
+
--- a/Linux/overlay_snap_ro-hook
+++ b/Linux/overlay_snap_ro-hook
@@ -0,0 +1,15 @@
+#!/usr/bin/ash
+
+run_latehook() {
+	local root_mnt="/new_root"
+	local current_dev=$(resolve_device "$root"); # resolve devices for blkid
+	if [[ $(blkid "${current_dev}" -s TYPE -o value) = "btrfs" ]] && [[ $(btrfs property get ${root_mnt} ro) != "ro=false" ]]; then # run only on a read only snapshot
+		local lower_dir=$(mktemp -d -p /)
+		local ram_dir=$(mktemp -d -p /)
+		mount --move ${root_mnt} ${lower_dir} # move new_root to lower_dir
+		mount -t tmpfs cowspace ${ram_dir}  #meuh!!! space, you can't test !
+		mkdir -p ${ram_dir}/upper
+		mkdir -p ${ram_dir}/work
+		mount -t overlay -o lowerdir=${lower_dir},upperdir=${ram_dir}/upper,workdir=${ram_dir}/work rootfs ${root_mnt}
+	fi
+}
--- a/Linux/overlay_snap_ro-install
+++ b/Linux/overlay_snap_ro-install
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+build() {
+    add_module btrfs
+    add_module overlay
+    add_binary btrfs
+    add_binary btrfsck
+    add_binary blkid
+    add_runscript
+}
+
+help() {
+    cat <<HELPEOF
+This hook uses overlayfs to boot on a read only snapshot.
+HELPEOF
+}
+
+# vim: set ft=sh ts=4 sw=4 et:
--- a/initramfs/readme.md
+++ b/initramfs/readme.md
@@ -0,0 +1,45 @@
+### Description :
+
+Booting on a snapshot in read-only mode can be tricky.  
+An elegant way is to boot this snapshot using overlayfs (included in the kernel ≥ 3.18).
+
+Using overlayfs, the booted snapshot will behave like a live-cd in non-persistent mode.  
+The snapshot will not be modified, the system will be able to boot correctly, because a writeable folder will be included in the ram.  
+(no more problems due to `/var` not open for writing)
+
+Any changes in this system thus started will be lost when the system is rebooted/shutdown.
+
+To do this, it is necessary to modify the initramfs.  
+This means that any snapshot that does not include this modified initramfs will not be able to benefit from it.  
+(except for separate boot partitions)
+#
+### Installation :
+#### Arch Linux
+1.
+`Pacman -S grub-btrfs`  
+Or if you use git  
+copy the `overlay_snap_ro-install` file to `/etc/initcpio/install/grub-btrfs-overlayfs`  
+copy the `overlay_snap_ro-hook` file to `/etc/initcpio/hooks/grub-btrfs-overlayfs`  
+You must rename the files. (I did it above)
+
+For example :  
+`overlay_snap_ro-install` to `grub-btrfs-overlayfs`  
+`overlay_snap_ro-hook` to `grub-btrfs-overlayfs`  
+Keep in mind that the files must have exactly the same name to ensure a match.
+
+2.
+Edit the file `/etc/mkinitcpio.conf`  
+Added hook `grub-btrfs-overlayfs` at the end of the line `HOOKS`.
+
+For example :  
+`HOOKS=(base udev autodetect modconf block filesystems keyboard fsck grub-btrfs-overlayfs)`  
+You notice that the name of the `hook` must match the name of the 2 installed files. (don't forget it)
+
+3.
+Re-generate your initramfs  
+`mkinitcpio -P` (option -P means, all preset present in `/etc/mkinitcpio.d`)
+
+#### Other distribution
+Refer to your distribution's documentation  
+or contribute to this project to add a paragraph.
+#
--- a/localisation/fr/grub-btrfs-git.mo
+++ b/localisation/fr/grub-btrfs-git.mo