Adds a new config variable "GRUB_BTRFS_ROOTFLAGS" (#133)

Script:

Improves the rootflags option in the kernel command line:
- Remove "rw" flag.
- Parse fstab mountoptions and add them to rootflags:
Adds functionality to read in  snapshot specific mount flags
from the respective fstab and uses them in combination with the new 
config option, while the latter is prioritized.
Both places can, but don't need to define mount flags. If either of them
doesn't, it will simply not be taken into account.

Config file:

Adds a new config variable "GRUB_BTRFS_ROOTFLAGS":
- The new variable is used to include user-defined rootflags in the 
kernel command line of generated snapshot bootmenu entries.
See config file for more infos.

10-update_grub.conf

@@ -1,2 +0,0 @@
-[Service]
-ExecStartPost=/usr/sbin/grub-mkconfig -o /boot/grub/grub.cfg

41_snapshots-btrfs

@@ -1,128 +1,102 @@
 #! /usr/bin/env bash
 #
 #
-#########################################################################################################################################################################
+# Written by: Antynea
-# Written by: Antynea																			#
+# BTC donation address: 1Lbvz244WA8xbpHek9W2Y12cakM6rDe5Rt
-# BTC donation address: 1Lbvz244WA8xbpHek9W2Y12cakM6rDe5Rt														#
+# Github: https://github.com/Antynea/grub-btrfs
-#																					#
+#
-# Purpose: Include btrfs snapshots at boot options (grub-menu).														#
+# Purpose:
-#																					#
+#   Improves Grub by adding "btrfs snapshots" to the Grub menu.
-# What this script does:																		#
+#   You can start your system on a "snapshot" from the Grub menu.
-# Simple rollback using snapshots you made previously.															#
+#   Supports manual snapshots, snapper ...
-# - Automatically List snapshots existing on root partition (btrfs).													#
+#   Warning : booting on read-only snapshots can be tricky
-# - Automatically Detect if "/boot" is in separate partition.														#
+#   (Read about it, https://github.com/Antynea/grub-btrfs#warning-booting-on-read-only-snapshots-can-be-tricky)
-# - Automatically Detect kernel, initramfs and intel microcode in "/boot" directory on snapshots. (For custon name, see below.)						#
+#
-# - Automatically Create corresponding "menuentry" in grub.cfg , which ensures a very easy rollback.									#
+# What this script does:
-# - Automatically detect snapper and use snapper's snapshot description if available.											#
+# - Automatically List snapshots existing on root partition (btrfs).
-#																					#
+# - Automatically Detect if "/boot" is in separate partition.
-# How to use it:																			#
+# - Automatically Detect kernel, initramfs and intel microcode in "/boot" directory on snapshots.
-# - Add this lines to /etc/default/grub:																#
+# - Automatically Create corresponding "menuentry" in grub.cfg
-#																					#
+# - Automatically detect snapper and use snapper's snapshot description if available.
-# * GRUB_BTRFS_SUBMENUNAME="Arch Linux snapshots" 															#
+# - Automatically generate grub.cfg if you use the provided systemd service.
-#	(Name appearing in the Grub menu.)																#
+#
-# * GRUB_BTRFS_PREFIXENTRY="Snapshot:"        		   														#
+# Installation:
-#	(Add a name ahead your snapshots entries in the Grub menu.) 													#
+# - Run `make install` or look into Makefile for instructions on where to put each file.
-# * GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT="true"																#
+#
-#	(Show full path snapshot or only name in the Grub menu)														#
+# Customization:
-# * GRUB_BTRFS_TITLE_FORMAT="p/d/n"																	#
+#  Refer to config for the list of available options and their default values.
-#	(Custom title, shows/hides p"prefix" d"date" n"name" in the Grub menu, separator "/", custom order available)							#
+#  Place your configurations to /etc/default/grub-btrfs/config.
-# * GRUB_BTRFS_LIMIT="100"																		#
+#
-#	(Limit the number of snapshots populated in the GRUB menu.)													#
+# Automatically update Grub
-# * GRUB_BTRFS_SUBVOLUME_SORT="descending"																#
+#  If you would like Grub to automatically update when a snapshots is made or deleted:
-#	(Sort the found subvolumes by newest first ("descending") or oldest first ("ascending").									#
+#  - Use systemctl start/enable grub-btrfs.path
-#	If "ascending" is chosen then the $GRUB_BTRFS_LIMIT oldest subvolumes will populate the menu.)									#
+#  - grub-btrfs.path automatically (re)generates grub.cfg when a modification appears in /.snapshots folder (by default).
-# * GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND="true"																#
+#  - If your snapshots aren't mounted in /.snapshots, you must modify the watch folder using systemctl edit grub-btrfs.path
-#	(Show snapshots found during run "grub-mkconfig")														#
+#  - See https://github.com/Antynea/grub-btrfs#automatically-update-grub
-# * GRUB_BTRFS_SHOW_TOTAL_SNAPSHOTS_FOUND="true"															#
+#
-#	(Show Total of snapshots found during run "grub-mkconfig")													#
+# Special thanks for assistance and contributions:
-# * GRUB_BTRFS_NKERNEL=("vmlinuz-linux") 		 														#
+# - My friends
-#	(Use only if you have custom kernel name or auto-detect failed.)												#
+# - All contributors on Github
-# * GRUB_BTRFS_NINIT=("initramfs-linux.img" "initramfs-linux-fallback.img")												#
+#
-#	(Use only if you have custom initramfs name or auto-detect failed.)												#
-# * GRUB_BTRFS_INTEL_UCODE=("intel-ucode.img") 																#
-#	(Use only if you have custom intel-ucode or auto-detect failed.)		    										#
-# * GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("var/lib/docker" "nosnapshot")													#
-#	(Ignore specific path during run "grub-mkconfig")														#
-# * GRUB_BTRFS_CREATE_ONLY_HARMONIZED_ENTRIES="false"															#
-#	(Create entries with matching version number instead of all possible combinations of kernel and initramfs)							#
-# * GRUB_BTRFS_SNAPPER_CONFIG="root"															#
-#	(Snapper's config name to use)							#
-#																					#
-# - Generate grub.cfg (on Arch Linux use grub-mkconfig -o /boot/grub/grub.cfg)												#
-#																					#
-# - grub-btrfs automatically generates snapshots entries.														#
-# - You will see it appear different entries (e.g : Snapshot: [2014-02-12 11:24:37] my snapshot name overkill)								#
-#																					#
-# Automatically update grub																		#
-#  If you would like grub to automatically update when Snapper timeline snapshots and cleanups occur, simply install 10-update_grub.conf in the following locations:	#
-# - /etc/systemd/system/snapper-timeline.service.d/															#
-# - /etc/systemd/system/snapper-cleanup.service.d/															#
-# Once the configuration files are in place, systemctl daemon-reload should be run to reload the units and make the changes active.					#
-#																					#
-#########################################################################################################################################################################
 
 set -e
 
-#prefix="/usr"
+prefix="/usr"
-#exec_prefix="${prefix}"
+exec_prefix="/usr"
 datarootdir="/usr/share"
-#datadir="${datarootdir}"
 sysconfdir="/etc"
+grub_btrfs_config="${sysconfdir}/default/grub-btrfs/config"
 
-. "${datarootdir}/grub/grub-mkconfig_lib"
+[[ -f "$grub_btrfs_config" ]] && . "$grub_btrfs_config"
+. "$datarootdir/grub/grub-mkconfig_lib"
 . "${sysconfdir}/default/grub"
 
-######################################
+### Variables in /etc/default/grub-btrfs/config
-### Variables in /etc/default/grub ###
+## Disable Grub-btrfs (default=active)
-######################################
+[[ "${GRUB_BTRFS_DISABLE:-"false"}" == "true" ]] && exit 0
 ## Submenu name
-submenuname=${GRUB_BTRFS_SUBMENUNAME:-"Arch Linux snapshots"}
+distro=$(awk -F "=" '/^NAME=/ {gsub(/"/, "", $2); print $2}' /etc/os-release)
+submenuname=${GRUB_BTRFS_SUBMENUNAME:-"${distro:-Linux} snapshots"}
 ## Prefix entry
 prefixentry=${GRUB_BTRFS_PREFIXENTRY:-"Snapshot:"}
-## Show full path snapshot or only name
+## Limit snapshots to show in the Grub menu
-path_snapshot=${GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT:-"true"}
+limit_snap_show="${GRUB_BTRFS_LIMIT:-50}"
-## Title format
-title_format=${GRUB_BTRFS_TITLE_FORMAT:-"p/d/n"}
-## Kernel(s) name(s)
-nkernel=("${GRUB_BTRFS_NKERNEL[@]}")
-## Initramfs name(s)
-ninit=("${GRUB_BTRFS_NINIT[@]}")
-## Microcode(s) name(s)
-microcode=("${GRUB_BTRFS_INTEL_UCODE[@]}")
-## Limit to show in the Grub menu
-limit_snap_show="${GRUB_BTRFS_LIMIT:-100}"
 ## How to sort snapshots list
-snap_list_sort=${GRUB_BTRFS_SUBVOLUME_SORT:-"descending"}
+btrfssubvolsort=(--sort="${GRUB_BTRFS_SUBVOLUME_SORT:-"-rootid"}")
-case "${snap_list_sort}" in
+## Snapper's config name
-    ascending)          btrfssubvolsort=("--sort=+rootid");;
-    *)                  btrfssubvolsort=("--sort=-rootid")
-esac
-## Show snapshots found during run "grub-mkconfig"
-show_snap_found=${GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND:-"true"}
-## Show Total of snapshots found during run "grub-mkconfig"
-show_total_snap_found=${GRUB_BTRFS_SHOW_TOTAL_SNAPSHOTS_FOUND:-"true"}
-## Ignore specific path during run "grub-mkconfig"
-ignore_specific_path=("${GRUB_BTRFS_IGNORE_SPECIFIC_PATH[@]}")
-## create only entries with harmonized version numbers
-harmonized_entries=${GRUB_BTRFS_CREATE_ONLY_HARMONIZED_ENTRIES:-"false"}
-## snapper's config name
 snapper_config=${GRUB_BTRFS_SNAPPER_CONFIG:-"root"}
+## Customize GRUB directory, where "grub.cfg" file is saved
+grub_directory=${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:-"false"}" in
+    true)   unrestricted_access_submenu="--unrestricted ";;
+    *)      unrestricted_access_submenu=""
+esac
+# Authorized users (--users foo,bar)
+if [ ! -z "${GRUB_BTRFS_PROTECTION_AUTHORIZED_USERS}" ] ; then
+    protection_authorized_users="--users ${GRUB_BTRFS_PROTECTION_AUTHORIZED_USERS} "
+fi
 
-
+### variables script
-########################
+## Probe info "Boot partition"
-### variables script ###
+# Boot device
-########################
+boot_device=$(${grub_probe} --target=device ${boot_directory})
-## Internationalization (default : english)
+# hints string
-export TEXTDOMAIN=grub-btrfs-git
+boot_hs=$(${grub_probe} --device ${boot_device} --target="hints_string" 2>/dev/null)
-export TEXTDOMAINDIR="/usr/share/locale"
+# UUID of the boot partition
-## hints string
+boot_uuid=$(${grub_probe} --device ${boot_device} --target="fs_uuid" 2>/dev/null)
-hs_boot=$(${grub_probe} --target="hints_string" "/boot" 2>/dev/null)
+# Type filesystem of boot partition
-## UUID of the boot partition
+boot_fs=$(${grub_probe} --device ${boot_device} --target="fs" 2>/dev/null)
-boot_uuid=$(${grub_probe} --target="fs_uuid" "/boot" 2>/dev/null)
+## Probe info "Root partition"
-## Type filesystem of boot partition
+# Type filesystem of root partition
-boot_fs=$(${grub_probe} --target="fs" "/boot" 2>/dev/null)
+root_fs=$(${grub_probe} --target="fs" / 2>/dev/null)
-## UUID of the root partition
+# Root device
-root_uuid=$(${grub_probe} "/" --target="fs_uuid" 2>/dev/null)
+root_device=$(${grub_probe} --target=device /)
+# UUID of the root partition
+root_uuid=$(${grub_probe} --device ${root_device} --target="fs_uuid" 2>/dev/null)
 ## Parameters passed to the kernel
 kernel_parameters="$GRUB_CMDLINE_LINUX $GRUB_CMDLINE_LINUX_DEFAULT"
 ## Mount point location
@@ -131,363 +105,449 @@ gbgmp=$(mktemp -d)
 CLASS="--class snapshots --class gnu-linux --class gnu --class os"
 ## save IFS
 oldIFS=$IFS
-## boot_dir (auto-detect if /boot is separate partition or not)
+## Detect uuid requirement (lvm,btrfs...)
-boot_dir()
+check_uuid_required() {
+if [ "x${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()
 {
-	boot_dir="$gbgmp/$snap_dir_name/boot"
+    local fstabflags=$(grep -oE '^\s*[^#][[:graph:]]+\s+/\s+btrfs\s+[[:graph:]]+' "${gbgmp}/${snap_dir_name}/etc/fstab" \
-	[[ "$root_uuid" != "$boot_uuid" ]] && boot_dir="/boot"
+                        | sed -E 's/^.*[[:space:]]([[:graph:]]+)$/\1/;s/,?subvol(id)?=[^,$]+//g;s/^,//')
-	echo "$boot_dir"
+    rootflags="rootflags=${fstabflags:+$fstabflags,}${GRUB_BTRFS_ROOTFLAGS:+$GRUB_BTRFS_ROOTFLAGS,}"
 }
 
+### Error Handling
+print_error()
+{
+    local arg="$@"
+    local nothing_to_do="If you think an error has occurred , please file a bug report at \" https://github.com/Antynea/grub-btrfs \"\nNothing to do. Abort.\n"
+    printf "${arg}\n${nothing_to_do}" >&2 ;
+    exit 0
+}
 
-##############
+test_btrfs()
-### Script ###
+{
-##############
+    [[ "$root_fs" != "btrfs" ]] && print_error "Root partition isn't a btrfs filesystem.\nThis script only supports snapshots of the btrfs filesystem."
+    set +e
+    type btrfs >/dev/null 2>&1
+    if [[ $? -ne 0 ]]; then
+        print_error "Unable to retrieve info from btrfs filesystem, make sure you have btrfs-progs on your system."
+    fi
+    set -e
+}
 
-### BEGIN auto detect ###
+### Script
+## Create entry
+entry()
+{
+echo "$@" >> "$grub_directory/grub-btrfs.cfg"
+}
 
 ## menu entries
-snapshots_entry()
+make_menu_entries()
 {
 ## \" required for snap,kernels,init,microcode with space in their name
-	echo "	submenu '$title_menu' {
+    entry "submenu '$title_menu' {
-		submenu '---> $title_menu <---' { echo }
+    submenu '---> $title_menu <---' { echo }"
-	"
+    for k in "${name_kernel[@]}"; do
-	for k in "${name_kernel[@]}"; do
+        [[ ! -f "${boot_dir}"/"${k}" ]] && continue;
-		for i in "${name_initramfs[@]}"; do
+        kversion=${k#*"-"}
-			for u in "${name_microcode[@]}"; do
+        for i in "${name_initramfs[@]}"; do
-			if [ -f "$(boot_dir)"/"${u}" ] ; then
+            prefix_i=${i%%"-"*}
-				echo "\
+            suffix_i=${i#*"-"}
-		menuentry '"${k}" & "${i}" & "${u}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid'{"
+            alt_suffix_i=${i##*"-"}
-			else 
+            if   [ "${kversion}" = "${suffix_i}" ];                 then i="${i}";
-				echo "\
+            elif [ "${kversion}.img" = "${suffix_i}" ];             then i="${i}";
-		menuentry '"${k}" & "${i}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid'{"
+            elif [ "${kversion}-fallback.img" = "${suffix_i}" ];    then i="${i}";
-			fi
+            elif [ "${kversion}.gz" = "${suffix_i}" ];              then i="${i}";
-			echo "\
+            else continue ;
-			$(save_default_entry)
+            fi
-			if [ x\$feature_all_video_module = xy ]; then
+            for u in "${name_microcode[@]}"; do
-				insmod all_video
+                if [[ "${name_microcode}" != "x" ]] ; then
-			fi
+                    entry "
-			set gfxpayload=keep
+    menuentry '"${k}" & "${i}" & "${u}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid' {"
-			insmod ${boot_fs}
+                else
-			if [ x\$feature_platform_search_hint = xy ]; then
+                    entry "
-				search --no-floppy --fs-uuid  --set=root ${hs_boot} ${boot_uuid}
+    menuentry '"${k}" & "${i}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid' {"
-			else
+                fi
-				search --no-floppy --fs-uuid  --set=root ${boot_uuid}
+                entry "\
-			fi
+        if [ x\$feature_all_video_module = xy ]; then
-			echo 'Loading Snapshot: "${snap_date_time}" "${snap_dir_name}"'
+        insmod all_video
-			echo 'Loading Kernel: "${k}" ...'
+        fi
-			linux \"${boot_dir_real_path}/"${k}"\" root=UUID=${root_uuid} rw rootflags=subvol=\""${snap_dir_name}"\" ${kernel_parameters}"
+        set gfxpayload=keep
-			if [ -f "$(boot_dir)"/"${u}" ] ; then
+        insmod ${boot_fs}
-				echo "\
+        if [ x\$feature_platform_search_hint = xy ]; then
-			echo 'Loading Microcode & Initramfs: "${u}" "${i}" ...'
+            search --no-floppy --fs-uuid  --set=root ${boot_hs} ${boot_uuid}
-			initrd \"${boot_dir_real_path}/"${u}"\" \"${boot_dir_real_path}/"${i}"\""
+        else
-			else
+            search --no-floppy --fs-uuid  --set=root ${boot_uuid}
-				echo "\
+        fi
-			echo 'Loading Initramfs: "${i}" ...'
+        echo 'Loading Snapshot: "${snap_date_time}" "${snap_dir_name}"'
-			initrd \"${boot_dir_real_path}/"${i}"\""
+        echo 'Loading Kernel: "${k}" ...'
-			fi
+        linux \"${boot_dir_root_grub}/"${k}"\" root="${LINUX_ROOT_DEVICE}" ${kernel_parameters} ${rootflags}subvol=\""${snap_dir_name}"\""
-		echo "		}"
+                if [[ "${name_microcode}" != "x" ]] ; then
-			done
+                    entry "\
-		done
+        echo 'Loading Microcode & Initramfs: "${u}" "${i}" ...'
-	done
+        initrd \"${boot_dir_root_grub}/"${u}"\" \"${boot_dir_root_grub}/"${i}"\""
-	echo "	}"
+                else
-}
+                    entry "\
-
+        echo 'Loading Initramfs: "${i}" ...'
-harmonized_snapshots_entry()
+        initrd \"${boot_dir_root_grub}/"${i}"\""
-{
+                fi
-## \" required for snap,kernels,init,microcode with space in their name
+                entry "    }"
-	echo "	submenu '$title_menu' {
+                count_warning_menuentries=$((1+$count_warning_menuentries))
-		submenu '---> $title_menu <---' { echo }
+            done
-	"
+        done
-	for k in "${name_kernel[@]}"; do
+    done
-		version=${k#vmlinuz-}
+    entry  "}"
-		i=""
-		if [ -f "$(boot_dir)"/initramfs-"${version}".img ]; then
-			i=initramfs-${version}.img
-		else
-			if [ -f "$(boot_dir)"/initrd.img-"${version}" ]; then
-				i=initrd.img-${version}
-			fi
-		fi
-		for u in "${name_microcode[@]}"; do
-			if [ -f "$(boot_dir)"/"${u}" ] ; then
-				echo "\
-		menuentry '"${k}" & "${i}" & "${u}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid'{"
-			else 
-				echo "\
-		menuentry '"${k}" & "${i}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid'{"
-			fi
-			echo "\
-			$(save_default_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 ${hs_boot} ${boot_uuid}
-			else
-				search --no-floppy --fs-uuid  --set=root ${boot_uuid}
-			fi
-			echo 'Loading Snapshot: "${snap_date_time}" "${snap_dir_name}"'
-			echo 'Loading Kernel: "${k}" ...'
-			linux \"${boot_dir_real_path}/"${k}"\" root=UUID=${root_uuid} rw rootflags=subvol=\""${snap_dir_name}"\" ${kernel_parameters}"
-			if [ -f "$(boot_dir)"/"${i}" ] ; then
-				if [ -f "$(boot_dir)"/"${u}" ] ; then
-					echo "\
-			echo 'Loading Microcode & Initramfs: "${u}" "${i}" ...'
-			initrd \"${boot_dir_real_path}/"${u}"\" \"${boot_dir_real_path}/"${i}"\""
-				else
-					echo "\
-			echo 'Loading Initramfs: "${i}" ...'
-			initrd \"${boot_dir_real_path}/"${i}"\""
-				fi
-			fi
-			echo "		}"
-		done
-	done
-	echo "	}"
 }
 
 ## Trim a string from leading and trailing whitespaces
 trim() {
-	local var="$*"
+    local var="$*"
-	var="${var#"${var%%[![:space:]]*}"}"
+    var="${var#"${var%%[![:space:]]*}"}"
-	var="${var%"${var##*[![:space:]]}"}"
+    var="${var%"${var##*[![:space:]]}"}"
-	echo -n "$var"
+    echo -n "$var"
 }
 
 ## List of snapshots on filesystem
 snapshot_list()
 {
-	# Query info from snapper if it is installed
+    # Query info from snapper if it is installed
-	type snapper >/dev/null 2>&1
+    type snapper >/dev/null 2>&1
-	if [[ $? -eq 0 ]]; then
+    if [ $? -eq 0 ]; then
-		local snapper_ids=($(snapper -t 0 -c "$snapper_config" list | tail -n +3 | cut -d'|' -f 2))
+        if [ -s "/etc/snapper/configs/$snapper_config" ]; then
-		local snapper_types=($(snapper -t 0 -c "$snapper_config" list | tail -n +3 | cut -d'|' -f 1))
+            printf "Info: snapper detected, using config '$snapper_config'\n" >&2
+            local snapper_ids=($(snapper --no-dbus -t 0 -c "$snapper_config" list --disable-used-space | tail -n +3 | cut -d'|' -f 1))
+            local snapper_types=($(snapper --no-dbus -t 0 -c "$snapper_config" list --disable-used-space | tail -n +3 | cut -d'|' -f 2))
 
-		IFS=$'\n'
+            IFS=$'\n'
-		local snapper_descriptions=($(snapper -t 0 -c "$snapper_config" list | tail -n +3 | cut -d'|' -f 7))
+            local snapper_descriptions=($(snapper --no-dbus -t 0 -c "$snapper_config" list --disable-used-space | tail -n +3 | rev | cut -d'|' -f 2 | rev))
-	fi
+        else
+            printf "Warning: snapper detected but config '$snapper_config' does not exist\n" >&2
+        fi
+    fi
 
-	IFS=$'\n'
+    IFS=$'\n'
 
-	# Parse btrfs snapshots
+    # Parse btrfs snapshots
-	local entries=()
+    local entries=()
-	local ids=()
+    local ids=()
-	local max_entry_length=0
+    local max_entry_length=0
-	for snap in $(btrfs subvolume list -sa "${btrfssubvolsort}" /); do
+    for snap in $(btrfs subvolume list -sa "${btrfssubvolsort}" /); do
-		IFS=$oldIFS
+        IFS=$oldIFS
-		snap=($snap)
+        snap=($snap)
-		local snap_path_name=${snap[@]:13:${#snap[@]}}
+        local snap_path_name=${snap[@]:13:${#snap[@]}}
-		# Discard deleted snapshots
-		if [ "$snap_path_name" = "DELETED" ]; then continue; fi
-		[[ ${snap_path_name%%"/"*} == "<FS_TREE>" ]] && snap_path_name=${snap_path_name#*"/"}
 
-		local id="${snap_path_name//[!0-9]}" # brutal way to get id: remove everything non-numeric
+        # Discard deleted snapshots
-		ids+=("$id")
+        if [ "$snap_path_name" = "DELETED" ]; then continue; fi
+        [[ ${snap_path_name%%"/"*} == "<FS_TREE>" ]] && snap_path_name=${snap_path_name#*"/"}
 
-		local entry="${snap[@]:10:2} | ${snap_path_name}"
+        # ignore specific path during run "grub-mkconfig"
-		entries+=("$entry")
+        if [ ! -z "${GRUB_BTRFS_IGNORE_SPECIFIC_PATH}" ] ; then
+            for isp in ${GRUB_BTRFS_IGNORE_SPECIFIC_PATH[@]} ; do
+                [[ "${snap_path_name}" == "${isp}" ]] && continue 2;
+            done
+        fi
+        if [ ! -z "${GRUB_BTRFS_IGNORE_PREFIX_PATH}" ] ; then
+            for isp in ${GRUB_BTRFS_IGNORE_PREFIX_PATH[@]} ; do
+                [[ "${snap_path_name}" == "${isp}"/* ]] && continue 2;
+            done
+        fi
 
-		# Find max length of a snapshot entry, needed for pretty formatting
+        # detect if /boot directory exists
-		local length="${#entry}"
+        [[ ! -d "$gbgmp/$snap_path_name/boot" ]] && continue;
-		[[ "$length" -gt "$max_entry_length" ]] && max_entry_length=$length
-	done
 
-	# Find max length of a snapshot type, needed for pretty formatting
+        local id="${snap_path_name//[!0-9]}" # brutal way to get id: remove everything non-numeric
-	local max_type_length=0
+        ids+=("$id")
-	for id in "${ids[@]}"; do
-		for j in "${!snapper_ids[@]}"; do
-			local snapper_id="${snapper_ids[$j]//[[:space:]]/}"
-			if [[ "$snapper_id" == "$id" ]]; then
-				local snapper_type=$(trim "${snapper_types[$j]}")
-				local length="${#snapper_type}"
-				[[ "$length" -gt "$max_type_length" ]] && max_type_length=$length
-			fi
-		done
-	done
 
-	for i in "${!entries[@]}"; do
+        local entry="${snap[@]:10:2} | ${snap_path_name}"
-		local id="${ids[$i]}"
+        entries+=("$entry")
-		local entry="${entries[$i]}"
-		for j in "${!snapper_ids[@]}"; do
-			local snapper_id="${snapper_ids[$j]//[[:space:]]/}"
-			if [[ "$snapper_id" == "$id" ]]; then
-				local snapper_type=$(trim "${snapper_types[$j]}")
-				local snapper_description=$(trim "${snapper_descriptions[$j]}")
-				printf -v entry "%-${max_entry_length}s | %-${max_type_length}s | %s" "$entry" "$snapper_type" "$snapper_description"
-				break
-			fi
-		done
-		echo "$entry"
-	done
 
-	IFS=$oldIFS
+        # Find max length of a snapshot entry, needed for pretty formatting
+        local length="${#entry}"
+        [[ "$length" -gt "$max_entry_length" ]] && max_entry_length=$length
+    done
+
+    # Find max length of a snapshot type, needed for pretty formatting
+    local max_type_length=0
+    for id in "${ids[@]}"; do
+        for j in "${!snapper_ids[@]}"; do
+            local snapper_id="${snapper_ids[$j]//[[:space:]]/}"
+            if [[ "$snapper_id" == "$id" ]]; then
+                local snapper_type=$(trim "${snapper_types[$j]}")
+                local length="${#snapper_type}"
+                [[ "$length" -gt "$max_type_length" ]] && max_type_length=$length
+            fi
+        done
+    done
+
+    for i in "${!entries[@]}"; do
+        local id="${ids[$i]}"
+        local entry="${entries[$i]}"
+        for j in "${!snapper_ids[@]}"; do
+            local snapper_id="${snapper_ids[$j]//[[:space:]]/}"
+            # remove other non numeric characters
+            snapper_id="${snapper_id//\*/}"
+            snapper_id="${snapper_id//\+/}"
+            snapper_id="${snapper_id//-/}"
+            if [[ "$snapper_id" == "$id" ]]; then
+                local snapper_type=$(trim "${snapper_types[$j]}")
+                local snapper_description=$(trim "${snapper_descriptions[$j]}")
+                printf -v entry "%-${max_entry_length}s | %-${max_type_length}s | %s" "$entry" "$snapper_type" "$snapper_description"
+                break
+            fi
+        done
+        echo "$entry"
+    done
+
+    IFS=$oldIFS
 }
 
 ## Detect kernels in "/boot"
 detect_kernel()
 {
-	## Arch original kernel (auto-detect)
+    list_kernel=()
-	for akernel in "$(boot_dir)"/vmlinuz-* ; do 
+    # Original kernel (auto-detect)
-		list_kernel+=("$akernel")
+    for okernel in  "${boot_dir}"/vmlinuz-* \
-	done
+                    "${boot_dir}"/vmlinux-* \
+                    "${boot_dir}"/kernel-* ; do
+        [[ ! -f "${okernel}" ]] && continue;
+        list_kernel+=("$okernel")
+    done
 
-	## Custom name kernel in GRUB_BTRFS_NKERNEL
+    # Custom name kernel in GRUB_BTRFS_NKERNEL
-	if [ ! -z "${nkernel}" ] ; then
+    if [ ! -z "${GRUB_BTRFS_NKERNEL}" ] ; then
-		for ckernel in "${nkernel[@]}" ; do
+        for ckernel in "${boot_dir}/${GRUB_BTRFS_NKERNEL[@]}" ; do
-			[[ ! -f /"$(boot_dir)"/"${ckernel}" ]] && continue;
+            [[ ! -f "${ckernel}" ]] && continue;
-			list_kernel+=("$ckernel")
+            list_kernel+=("$ckernel")
-		done
+        done
-	fi
+    fi
 }
 
 ## Detect initramfs in "/boot"
 detect_initramfs()
 {
-	## Arch original initramfs (auto-detect)
+    list_initramfs=()
-	for ainitramfs in "$(boot_dir)"/initramfs-* ; do 
+    # Original initramfs (auto-detect)
-		list_initramfs+=("$ainitramfs")
+    for oinitramfs in   "${boot_dir}"/initrd.img-* \
-	done
+                        "${boot_dir}"/initrd-*.img \
+                        "${boot_dir}"/initrd-*.gz \
+                        "${boot_dir}"/initramfs-*.img \
+                        "${boot_dir}"/initramfs-*.gz ; do
+        [[ ! -f "${oinitramfs}" ]] && continue;
+        list_initramfs+=("$oinitramfs")
+    done
 
-	## Custom name initramfs in GRUB_BTRFS_NINIT
+    # Custom name initramfs in GRUB_BTRFS_NINIT
-	if [ ! -z "$ninit" ] ; then
+    if [ ! -z "${GRUB_BTRFS_NINIT}" ] ; then
-		for cinitramfs in "${ninit[@]}" ; do
+        for cinitramfs in "${boot_dir}/${GRUB_BTRFS_NINIT[@]}" ; do
-			[[ ! -f /"$(boot_dir)"/"${cinitramfs}" ]] && continue;
+            [[ ! -f "${cinitramfs}" ]] && continue;
-			list_initramfs+=("$cinitramfs")
+            list_initramfs+=("$cinitramfs")
-		done
+        done
-	fi
+    fi
 }
 
 ## Detect microcode in "/boot"
 detect_microcode()
 {
-	## Arch original intel microcode
+    list_ucode=()
-	for aucode in "$(boot_dir)"/intel-ucode.img ; do
+    # Original intel/amd microcode (auto-detect)
-		list_ucode+=("$aucode")
+    # See "https://www.gnu.org/software/grub/manual/grub/html_node/Simple-configuration.html"
-	done
+    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_INTEL_UCODE
+    # Custom name microcode in GRUB_BTRFS_CUSTOM_MICROCODE
-	if [ ! -z "$microcode" ] ; then
+    if [ ! -z "${GRUB_BTRFS_CUSTOM_MICROCODE}" ] ; then
-		for cucode in "${microcode[@]}" ; do
+        for cucode in "${boot_dir}/${GRUB_BTRFS_CUSTOM_MICROCODE[@]}" ; do
-			[[ ! -f /"$(boot_dir)"/"${cucode}" ]] && continue
+            [[ ! -f "${cucode}" ]] && continue
-			list_ucode+=("$cucode")
+            list_ucode+=("$cucode")
-		done
+        done
-	fi
+    fi
+    if [ -z "${list_ucode}" ]; then list_ucode=(x); fi
 }
 
 ## Show full path snapshot or only name
 path_snapshot()
 {
-	case "${path_snapshot}" in
+    case "${GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT:-"true"}" in
-		true) name_snapshot=("${snap_full_name}");;
+        true) name_snapshot=("${snap_full_name}");;
-		*) name_snapshot=("${snap_full_name#*"/"}")
+        *)    name_snapshot=("${snap_full_name#*"/"}")
-	esac
+    esac
 }
 
 ## Title format in grub-menu
 title_format()
 {
-	case "${title_format}" in
+    case "${GRUB_BTRFS_TITLE_FORMAT:-"p/d/n"}" in
-		p/d/n) 	title_menu="${prefixentry} ${snap_date_time} ${name_snapshot}";;
+        p/n/d)  title_menu="${prefixentry} ${name_snapshot} ${snap_date_time}";;
-		p/n/d) 	title_menu="${prefixentry} ${name_snapshot} ${snap_date_time}";;
+        p/d)    title_menu="${prefixentry} ${snap_date_time}";;
-		p/d) 	title_menu="${prefixentry} ${snap_date_time}";;
+        p/n)    title_menu="${prefixentry} ${name_snapshot}";;
-		p/n) 	title_menu="${prefixentry} ${name_snapshot}";;
+        d/n)    title_menu="${snap_date_time} ${name_snapshot}";;
-		d/n) 	title_menu="${snap_date_time} ${name_snapshot}";;
+        n/d)    title_menu="${name_snapshot} ${snap_date_time}";;
-		n/d) 	title_menu="${name_snapshot} ${snap_date_time}";;
+        p)      title_menu="${prefixentry}";;
-		p) 	title_menu="${prefixentry}";;
+        d)      title_menu="${snap_date_time}";;
-		d)	title_menu="${snap_date_time}";;
+        n)      title_menu="${name_snapshot}";;
-		n)	title_menu="${name_snapshot}";;
+        *)      title_menu="${prefixentry} ${snap_date_time} ${name_snapshot}"
-		*)	gettext_printf $"# Warning: GRUB_BTRFS_TITLE_FORMAT=${title_format}, syntax error \n" >&2
+    esac
-	esac
 }
 
 ## List of kernels, initramfs and microcode in snapshots
-list_kernels_initramfs()
+boot_bounded()
 {
-	IFS=$'\n'
+    # Initialize menu entries
-	count_limit_snap=0
+    IFS=$'\n'
-	for item in $(snapshot_list); do
+    for item in $(snapshot_list); do
-		### fix: limit_snap_show=0
+        [[ ${limit_snap_show} -le 0 ]] && break; # fix: limit_snap_show=0
-		[[ ${limit_snap_show} -le 0 ]] && break;
+        IFS=$oldIFS
-		IFS=$oldIFS
+        snap_full_name="$(echo "$item" | cut -d'|' -f2-)" # do not trim it to keep nice formatting
-		snap_full_name="$(echo "$item" | cut -d'|' -f2-)" # do not trim it to keep nice formatting
+        snap_dir_name="$(echo "$item" | cut -d'|' -f2)"
-		snap_dir_name="$(echo "$item" | cut -d'|' -f2)"
+        snap_dir_name="$(trim "$snap_dir_name")"
-		snap_dir_name="$(trim "$snap_dir_name")"
+        snap_date_time="$(echo "$item" | cut -d' ' -f1-2)"
+        snap_date_time="$(trim "$snap_date_time")"
         
-		### ignore specific path during run "grub-mkconfig"
+        boot_dir="$gbgmp/$snap_dir_name$boot_directory"
-		if [ ! -z "${ignore_specific_path}" ] ; then
+        # Kernel (Original + custom kernel)
-			for isp in ${ignore_specific_path[@]} ; do
+        detect_kernel
-				[[ "${gbgmp}"/"${snap_dir_name}" == "${gbgmp}"/"${isp}"/* ]] && continue 2;
+        if [ -z "${list_kernel}" ]; then continue; fi
-			done
+        name_kernel=("${list_kernel[@]##*"/"}")
-		fi
+        # Detect rootflags
-		### detect if /boot directory exists
+        detect_rootflags
-		[[ ! -d "$gbgmp/$snap_dir_name/boot" ]] && continue;
+        # Initramfs (Original + custom initramfs)
-		### show snapshot found during run "grub-mkconfig"
+        detect_initramfs
-		snap_date_time="$(echo "$item" | cut -d' ' -f1-2)"
+        if [ -z "${list_initramfs}" ]; then continue; fi
-		snap_date_time="$(trim "$snap_date_time")"
+        name_initramfs=("${list_initramfs[@]##*"/"}")
-		if [[ "${show_snap_found}" = "true" ]]; then
+        # microcode (auto-detect + custom microcode)
-		gettext_printf $"# Found snapshot: %s\n" "$item" >&2 ;
+        detect_microcode
-		fi
+        name_microcode=("${list_ucode[@]##*"/"}")
-		### Kernel (auto-detect + custom kernel)
+        # show snapshot found during run "grub-mkconfig"
-		unset list_kernel
+        if [[ "${GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND:-"true"}" = "true" ]]; then
-		detect_kernel
+            printf "Found snapshot: %s\n" "$item" >&2 ;
-		name_kernel=("${list_kernel[@]##*"/"}")
+        fi
-		# echo "kernel = ${name_kernel[*]}"
+        # Show full path snapshot or only name
-		if [[ "${harmonized_entries}" != "true" ]]; then
+        path_snapshot
-			### Initramfs (autodetect + custom initramfs)
+        # Title format in grub-menu
-			unset list_initramfs
+        title_format
-			detect_initramfs
+        # convert /boot directory to root of GRUB (e.g /boot become /)
-			name_initramfs=("${list_initramfs[@]##*"/"}")
+        boot_dir_root_grub="$(make_system_path_relative_to_its_root "${boot_dir}")"
-			# echo "initramfs = ${name_initramfs[*]}"
+        # Make menuentries
-		fi
+        make_menu_entries
-		### microcode (auto-detect + custom microcode)
+        ### Limit snapshots found during run "grub-mkconfig"
-		unset list_ucode
+        count_limit_snap=$((1+$count_limit_snap))
-		detect_microcode
+        [[ $count_limit_snap -ge $limit_snap_show ]] && break;
-		name_microcode=("${list_ucode[@]##*"/"}")
+        # Limit generation of menuentries if exceeds 250
-		# echo "ucode = ${name_microcode[*]}"
+        # [[ $count_warning_menuentries -ge 250 ]] && break;
-		### real path to boot
+    done
-		boot_dir_real_path="$(make_system_path_relative_to_its_root "$(boot_dir)")"
+    IFS=$oldIFS
-		### Create menu entries
-		## name snapshot
-		path_snapshot
-		## title menu custom
-		title_format
-		# echo "${title_menu}"
-		if [[ "${harmonized_entries}" = "false" ]]; then
-			snapshots_entry
-		else
-			harmonized_snapshots_entry
-		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
 }
-### END auto detect ###
+boot_separate()
+{
+    boot_dir="${boot_directory}"
+    # convert /boot directory to root of GRUB (e.g /boot become /)
+    boot_dir_root_grub="$(make_system_path_relative_to_its_root "${boot_dir}")"
 
-### Start ###
+    # Kernel (Original + custom kernel)
-	gettext_printf "###### - Grub-btrfs: Auto-detect Start - ######\n" >&2 ;
+    detect_kernel
-	### create mount point and mounts
+    if [ -z "${list_kernel}" ]; then print_error "Kernels not found."; fi
-	[[ ! -d $gbgmp ]] && mkdir -p $gbgmp
+    name_kernel=("${list_kernel[@]##*"/"}")
-	mount -o subvolid=5 /dev/disk/by-uuid/$root_uuid $gbgmp/
+    # Initramfs (Original + custom initramfs)
-	### Create a menu in grub
+    detect_initramfs
-	echo "submenu '${submenuname}' {"
+    if [ -z "${list_initramfs}" ]; then print_error "Initramfs not found."; fi
-	list_kernels_initramfs ;
+    name_initramfs=("${list_initramfs[@]##*"/"}")
-	## show total found snapshots
+    # microcode (auto-detect + custom microcode)
-	if [[ "${show_total_snap_found}" = "true" ]]; then
+    detect_microcode
-	gettext_printf "# Found ${count_limit_snap} snapshot(s)\n" >&2 ;
+    name_microcode=("${list_ucode[@]##*"/"}")
-	fi
+
-	## if no snapshot found, show a warning 
+    # Initialize menu entries
-	if [[ "${count_limit_snap}" = "0" ]]; then
+    IFS=$'\n'
-		echo " submenu '---> "No snapshot found : Press ESC to return previous menu" <---' { echo } ";
+    for item in $(snapshot_list); do
-		gettext_printf "# No snapshot found \n# make sure you have at least one snapshot \n# or please file a bug report at \"https://github.com/Antynea/grub-btrfs\"\n" >&2 ;
+        [[ ${limit_snap_show} -le 0 ]] && break; # fix: limit_snap_show=0
-	fi
+        IFS=$oldIFS
-	echo "}"
+        snap_full_name="$(echo "$item" | cut -d'|' -f2-)" # do not trim it to keep nice formatting
-	## unmount mount point
+        snap_dir_name="$(echo "$item" | cut -d'|' -f2)"
-	umount $gbgmp
+        snap_dir_name="$(trim "$snap_dir_name")"
-	gettext_printf "###### - Grub-btrfs: Auto-detect End   - ######\n" >&2 ;
+        snap_date_time="$(echo "$item" | cut -d' ' -f1-2)"
-### End ###
+        snap_date_time="$(trim "$snap_date_time")"
+        # Detect rootflags
+        detect_rootflags
+        # show snapshot found during run "grub-mkconfig"
+        if [[ "${GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND:-"true"}" = "true" ]]; then
+            printf "Found snapshot: %s\n" "$item" >&2 ;
+        fi
+        # Show full path snapshot or only name
+        path_snapshot
+        # Title format in grub-menu
+        title_format
+        # Make menuentries
+        make_menu_entries
+        # Limit snapshots found during run "grub-mkconfig"
+        count_limit_snap=$((1+$count_limit_snap))
+        [[ $count_limit_snap -ge $limit_snap_show ]] && break;
+        # Limit generation of menuentries if exceeds 250
+        # [[ $count_warning_menuentries -ge 250 ]] && break;
+    done
+    IFS=$oldIFS
+}
+
+### Start
+printf "Detecting snapshots ...\n" >&2 ;
+# Only support btrfs snapshots
+test_btrfs
+# Delete existing config
+#rm -f --preserve-root "$grub_directory/grub-btrfs.cfg"
+> "$grub_directory/grub-btrfs.cfg"
+# Create mount point then mounting
+[[ ! -d $gbgmp ]] && mkdir -p $gbgmp
+mount -o subvolid=5 /dev/disk/by-uuid/$root_uuid $gbgmp/
+# Count menuentries
+count_warning_menuentries=0
+# Count snapshots
+count_limit_snap=0
+# detect uuid requirement
+check_uuid_required
+# Detects if /boot is a separate partition
+if [[ "${GRUB_BTRFS_OVERRIDE_BOOT_PARTITION_DETECTION:-"false"}" == "true" ]]; then
+    printf "Info: Override boot partition detection : enable \n" >&2 ;
+    boot_separate
+else
+    if [[ "$root_uuid" != "$boot_uuid" ]]; then
+        printf "Info: Separate boot partition detected \n" >&2 ;
+        boot_separate
+    else
+        printf "Info: Separate boot partition not detected \n" >&2 ;
+        boot_bounded
+    fi
+fi
+# unmounting mount point
+umount $gbgmp
+# Show warn, menuentries exceeds 250 entries
+[[ $count_warning_menuentries -ge 250 ]] && printf "Generated ${count_warning_menuentries} total GRUB entries. You might experience issues loading snapshots menu in GRUB.\n" >&2 ;
+# printf "menuentries = $count_warning_menuentries \n" >&2 ;
+# Show total found snapshots
+if [[ "${GRUB_BTRFS_SHOW_TOTAL_SNAPSHOTS_FOUND:-"true"}" = "true" && ! -z "${count_limit_snap}" && "${count_limit_snap}" != "0" ]]; then
+    printf "Found ${count_limit_snap} snapshot(s)\n" >&2 ;
+fi
+# if no snapshot found, exit
+if [[ "${count_limit_snap}" = "0" || -z "${count_limit_snap}" ]]; then
+    print_error "No snapshots found."
+fi
+# Make a submenu in GRUB (grub.cfg)
+cat << EOF
+submenu '${submenuname}' ${protection_authorized_users}${unrestricted_access_submenu}{
+    configfile "\${prefix}/grub-btrfs.cfg"
+}
+EOF
+### End

Makefile

@@ -0,0 +1,60 @@
+PKGNAME ?= grub-btrfs
+PREFIX ?= /usr
+
+SHARE_DIR = $(DESTDIR)$(PREFIX)/share
+LIB_DIR = $(DESTDIR)$(PREFIX)/lib
+
+.PHONY: install uninstall help
+
+install:
+	@install -Dm755 -t "$(DESTDIR)/etc/grub.d/" 41_snapshots-btrfs
+	@install -Dm644 -t "$(DESTDIR)/etc/default/grub-btrfs/" config
+	@install -Dm644 -t "$(LIB_DIR)/systemd/system/" grub-btrfs.service
+	@install -Dm644 -t "$(LIB_DIR)/systemd/system/" grub-btrfs.path
+	@install -Dm644 -t "$(SHARE_DIR)/licenses/$(PKGNAME)/" LICENSE
+	@# Arch Linux like distros only :
+	@if command -V mkinitcpio >/dev/null 2>&1; 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 "$(SHARE_DIR)/doc/$(PKGNAME)/" README.md
+	@install -Dm644 "initramfs/readme.md" "$(SHARE_DIR)/doc/$(PKGNAME)/initramfs-overlayfs.md"
+
+uninstall:
+	@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 "$(LIB_DIR)/systemd/system/grub-btrfs.service"
+	@rm -f "$(LIB_DIR)/systemd/system/grub-btrfs.path"
+	@rm -f "$(LIB_DIR)/initcpio/install/grub-btrfs-overlayfs"
+	@rm -f "$(LIB_DIR)/initcpio/hooks/grub-btrfs-overlayfs"
+	@# Arch Linux unlike distros only :
+	@if ! command -V mkinitcpio >/dev/null 2>&1; 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: $(MAKE) [ <parameter>=<value> ... ] [ <action> ]"
+	@echo
+	@echo "  actions: install"
+	@echo "           uninstall"
+	@echo "           help"
+	@echo
+	@echo "  parameters | description                    | defaults"
+	@echo "  -----------+--------------------------------+----------------------------"
+	@echo "  DESTDIR    | install destination            | <unset>"
+	@echo "  PREFIX     | system tree prefix             | '/usr'"
+	@echo "  SHARE_DIR  | shared data location           | '\$$(DESTDIR)\$$(PREFIX)/share'"
+	@echo "  LIB_DIR    | system libraries location      | '\$$(DESTDIR)\$$(PREFIX)/lib'"
+	@echo "  PKGNAME    | name of the ditributed package | 'grub-btrfs'"
+	@echo

README.md

@@ -1,115 +1,79 @@
-[![GitHub release](https://img.shields.io/github/release/Antynea/grub-btrfs.svg)](https://github.com/Antynea/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
 
-This is a version 2.xx of grub-btrfs
+This is a version 4.xx of grub-btrfs
-##### BTC donation address: 1Lbvz244WA8xbpHek9W2Y12cakM6rDe5Rt
+##### BTC donation address: `1Lbvz244WA8xbpHek9W2Y12cakM6rDe5Rt`
 ##
 ### Description
+Improves Grub by adding "btrfs snapshots" to the Grub menu.
+
+You can start 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).
 
-grub-btrfs, Include btrfs snapshots at boot options. (grub menu)
 ##
-### What does grub-btrfs v2.xx do :
+### What does grub-btrfs v4.xx do :
-
-Simple rollback using snapshots you made previously.
-
 * 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 Detect kernel, initramfs and intel microcode in "/boot" directory on snapshots. (For custom name, see below.)
+* Automatically Create corresponding "menuentry" in `grub.cfg`
-
-* Automatically Create corresponding "menuentry" in grub.cfg , which ensures a very easy rollback.
-
 * Automatically detect snapper and use snapper's snapshot description if available.
+* Automatically generate `grub.cfg` if you use the provided systemd service.
+
 ##
-### How to use it:
+### Installation :
+#### Arch Linux
 
-Add this lines to /etc/default/grub:
+```
+pacman -S grub-btrfs
+```
 
-* GRUB_BTRFS_SUBMENUNAME="Arch Linux Snapshots"
+#### Manual
 
-	(Name menu appearing in grub.)
+* Run `make install` or look into Makefile for instructions on where to put each file.
 
-* GRUB_BTRFS_PREFIXENTRY="Snapshot:"
+NOTE: Generate your Grub menu after installation for the changes to take effect.  
+On Arch Linux use `grub-mkconfig -o /boot/grub/grub.cfg`.
 
-	(Add a name ahead your snapshots entries.)
+##
+### Customization:
 
-* GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT="true"
+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.
 
-	(Show full path snapshot or only name, weird reaction with snapper)
-	
-* GRUB_BTRFS_TITLE_FORMAT="p/d/n"
-
- 	(Custom title, shows/hides p"prefix" d"date" n"name" in grub-menu, separator "/", custom order available)
-
-* GRUB_BTRFS_NKERNEL=("vmlinuz-linux")
-
-	(Use only if you have a custom kernel name or auto-detect failed.)
-
-* GRUB_BTRFS_NINIT=("initramfs-linux.img" "initramfs-linux-fallback.img")
-
-	(Use only if you have a custom initramfs name or auto-detect failed.)
-
-* GRUB_BTRFS_INTEL_UCODE=("intel-ucode.img")
-
-	(Use only if you have custom intel-ucode or auto-detect failed.)
-
-* GRUB_BTRFS_LIMIT="100"
-
-	(Limit the number of snapshots populated in the GRUB menu.)
-
-* GRUB_BTRFS_SUBVOLUME_SORT="descending"
-
-	(Sort the found subvolumes by newest first ("descending") or oldest first ("ascending"). 
-	If "ascending" is chosen then the $GRUB_BTRFS_LIMIT oldest
-	subvolumes will populate the menu.)
-
-* GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND="true"
-	
-	(Show snapshots found during run "grub-mkconfig") 
-	
-* GRUB_BTRFS_SHOW_TOTAL_SNAPSHOTS_FOUND="true"
-	
-	(Show Total number of snapshots found during run "grub-mkconfig")
-
-* GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("var/lib/docker" "nosnapshot")
-
-	(Ignore specific path during run "grub-mkconfig")
-
-* GRUB_BTRFS_CREATE_ONLY_HARMONIZED_ENTRIES="false"
-
-	(Create entries with matching version number instead of all possible combinations of kernel and initramfs, very useful with debian-like distributions)
-
-
-
-Generate grub.cfg (on Arch linux use grub-mkconfig -o /boot/grub/grub.cfg )
-
-grub-btrfs automatically generates snapshots entries.
-
-You will see it appear differents entries (e.g : Snapshot: 2018-01-03 15:08:41  @test1 )
 ##
 ### Automatically update grub
+If you would like Grub to automatically update when a snapshot is made or deleted:
+* Use `systemctl start/enable grub-btrfs.path`.
+* `grub-btrfs.path` automatically (re)generates `grub.cfg` when a modification appears in `/.snapshots` folder (by default).
+* If your snapshots aren't mounted in `/.snapshots`, you must modify the watch folder using `systemctl edit grub-btrfs.path`.  
+	* For example: Timeshift mount its snapshots in `/run/timeshift/backup/timeshift-btrfs/snapshots` folder.
 
-If you would like grub to automatically update when Snapper timeline snapshots and cleanups occur, simply install `10-update_grub.conf` in the following locations:
+		Use `systemctl edit grub-btrfs.path`.
-
+		Then wrote:
-- `/etc/systemd/system/snapper-timeline.service.d/`
+		```
-- `/etc/systemd/system/snapper-cleanup.service.d/`
+		[Path]
-
+		PathModified=/run/timeshift/backup/timeshift-btrfs/snapshots
-Once the configuration files are in place, `systemctl daemon-reload` should be run to reload the units and make the changes active.
+		```
-
+		and finally save.
-##
+	* You can view your change to `systemctl cat grub-btrfs.path`.
-### Discussion
+	* To revert change use `systemctl revert grub-btrfs.path`.
-Pour les francophones : https://forums.archlinux.fr/viewtopic.php?f=18&t=17177
+##### 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
-
 * [maximbaz](https://github.com/maximbaz)
-* [crossroads1112](https://github.com/crossroads1112)
+* [All contributors](https://github.com/Antynea/grub-btrfs/graphs/contributors)
-* [penetal](https://github.com/penetal)
-* [wesbarnett](https://github.com/wesbarnett)
-* [Psykar](https://github.com/Psykar)
-* [anyc](https://github.com/anyc)
-* [daftaupe](https://github.com/daftaupe)
-* [N-Parsons](https://github.com/N-Parsons)
 ##

config

@@ -0,0 +1,122 @@
+#!/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"
+
+# Add a name ahead your snapshots entries in the Grub menu.
+# Default: "Snapshot:"
+#GRUB_BTRFS_PREFIXENTRY="Snapshot:"
+
+# Show full path snapshot or only name in the Grub menu, weird reaction with snapper.
+# Default: "true"
+#GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT="false"
+
+# Custom title.
+# shows/hides p"prefix" d"date" n"name" in the Grub menu, separator "/", custom order available.
+# Default: "p/d/n"
+#GRUB_BTRFS_TITLE_FORMAT="p/d/n"
+
+# 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"
+
+# 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")
+
+# By default "grub-btrfs" automatically detects your boot partition,
+# either located at the system root or on a separate partition,
+# but cannot detect if it is in a subvolume.
+# Change to "true" if you have a boot partition in a different subvolume.
+# 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
+
+# Snapper
+# Snapper's config name to use
+# Default: "root"
+#GRUB_BTRFS_SNAPPER_CONFIG="root"
+
+# 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"

grub-btrfs.path

@@ -0,0 +1,8 @@
+[Unit]
+Description=Monitors for new snapshots
+
+[Path]
+PathModified=/.snapshots
+
+[Install]
+WantedBy=multi-user.target

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' 

initramfs/Arch 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
+}

initramfs/Arch 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:

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.
+#