Makefile: Make sure make is invoked with appropriate permissions (#146)

* 41_snapshots: update header
  * Update "Automatically update Grub" section.
  * Update "Purpose" section.
  * Update "What this script does" section

41_snapshots-btrfs

@@ -1,22 +1,22 @@
 #! /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 start your system on a "snapshot" from the Grub menu.
+#   You can boot your system on a "snapshot" from the Grub menu.
-#   Supports manual snapshots, snapper ...
+#   Supports manual snapshots, snapper, timeshift ...
-#   Warning : it isn't recommended to start on read-only snapshot
+#   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 microcode in "/boot" directory on snapshots.
+# - Automatically Detect kernel, initramfs and intel/amd microcode in "/boot" directory on snapshots.
-# - Automatically Create corresponding "menuentry" in grub.cfg
+# - Automatically Create corresponding "menuentry" in grub.cfg.
 # - Automatically detect snapper and use snapper's snapshot description if available.
 # - Automatically generate grub.cfg if you use the provided systemd service.
 #
@@ -24,20 +24,16 @@
 # - Run `make install` or look into Makefile for instructions on where to put each file.
 #
 # Customization:
-#  Refer to config for the list of available options and their default values.
+#  You have the possibility to modify many parameters in /etc/default/grub-btrfs/config.
-#  Place your configurations to /etc/default/grub-btrfs/config.
 #
 # Automatically update Grub
-#  If you would like Grub to automatically update when a snapshots is made or deleted:
+#  If you would like grub-btrfs menu to automatically update when a snapshot is created or deleted:
-# - Mount your subvolume which contains snapshots to /.snapshots
+#  - Refer to https://github.com/Antynea/grub-btrfs#automatically-update-grub.
-# - Use systemctl start/enable grub-btrfs.path
-#  grub-btrfs.path will automatically (re)generate grub.cfg when a modification appear in /.snapshots
 #
 # Special thanks for assistance and contributions:
 # - My friends
 # - All contributors on Github
 #
-#########################################################################################################################################################################
 
 set -e
 
@@ -51,63 +47,48 @@ grub_btrfs_config="${sysconfdir}/default/grub-btrfs/config"
 . "$datarootdir/grub/grub-mkconfig_lib"
 . "${sysconfdir}/default/grub"
 
-###################################################
+### Variables in /etc/default/grub-btrfs/config
-### Variables in /etc/default/grub-btrfs/config ###
-###################################################
 ## Disable Grub-btrfs (default=active)
-grub_btrfs_disable=${GRUB_BTRFS_DISABLE:-"false"}
+[[ "${GRUB_BTRFS_DISABLE:-"false"}" == "true" ]] && exit 0
-[[ "${grub_btrfs_disable}" == "true" ]] && exit 0
 ## Submenu name
-submenuname=${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
-path_snapshot=${GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT:-"true"}
-## Title format
-title_format=${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=("${GRUB_BTRFS_INTEL_UCODE[@]}")
 ## Limit snapshots to show in the Grub menu
 limit_snap_show="${GRUB_BTRFS_LIMIT:-50}"
 ## How to sort snapshots list
-snap_list_sort=${GRUB_BTRFS_SUBVOLUME_SORT:-"descending"}
+btrfssubvolsort=(--sort="${GRUB_BTRFS_SUBVOLUME_SORT:-"-rootid"}")
-case "${snap_list_sort}" in
-    ascending)          btrfssubvolsort=("--sort=+rootid");;
-    *)                  btrfssubvolsort=("--sort=-rootid")
-esac
-## Show snapshots found during run "grub-mkconfig"
-show_snap_found=${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[@]}")
 ## Snapper's config name
 snapper_config=${GRUB_BTRFS_SNAPPER_CONFIG:-"root"}
-## Override boot partition detection
+## Customize GRUB directory, where "grub.cfg" file is saved
-override_boot_partition_detection=${GRUB_BTRFS_OVERRIDE_BOOT_PARTITION_DETECTION:-"false"}
+grub_directory=${GRUB_BTRFS_GRUB_DIRNAME:-"/boot/grub"}
-## Customize GRUB directory
+## Customize BOOT directory, where kernels/initrams/microcode is saved.
-grub_directory=${GRUB_BTRFS_DIRNAME:-"grub"}
+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
-### variables script ###
-########################
-## Internationalization (default : english)
-export TEXTDOMAIN=grub-btrfs-git
-export TEXTDOMAINDIR="/usr/share/locale"
 ## Probe info "Boot partition"
 # Boot device
-boot_device=$(${grub_probe} --target=device /boot)
+boot_device=$(${grub_probe} --target=device ${boot_directory})
 # hints string
 boot_hs=$(${grub_probe} --device ${boot_device} --target="hints_string" 2>/dev/null)
 # UUID of the boot partition
 boot_uuid=$(${grub_probe} --device ${boot_device} --target="fs_uuid" 2>/dev/null)
 # Type filesystem of boot partition
-boot_fs=$(${grub_probe} --target="fs" /boot 2>/dev/null)
+boot_fs=$(${grub_probe} --device ${boot_device} --target="fs" 2>/dev/null)
 ## Probe info "Root partition"
+# Type filesystem of root partition
+root_fs=$(${grub_probe} --target="fs" / 2>/dev/null)
 # Root device
 root_device=$(${grub_probe} --target=device /)
 # UUID of the root partition
@@ -125,391 +106,405 @@ check_uuid_required() {
 if [ "x${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=${root_device}
+    LINUX_ROOT_DEVICE=${root_device}
 else
-  LINUX_ROOT_DEVICE=UUID=${root_uuid}
+    LINUX_ROOT_DEVICE=UUID=${root_uuid}
 fi
 }
+## Detect rootflags
+detect_rootflags()
+{
+    local fstabflags=$(grep -oE '^\s*[^#][[:graph:]]+\s+/\s+btrfs\s+[[:graph:]]+' "${gbgmp}/${snap_dir_name}/etc/fstab" \
+                        | sed -E 's/^.*[[:space:]]([[:graph:]]+)$/\1/;s/,?subvol(id)?=[^,$]+//g;s/^,//')
+    rootflags="rootflags=${fstabflags:+$fstabflags,}${GRUB_BTRFS_ROOTFLAGS:+$GRUB_BTRFS_ROOTFLAGS,}"
+}
 
-
+### Error Handling
-######################
-### Error Handling ###
-######################
 print_error()
 {
-	local arg="$@"
+    local arg="$@"
-	local nothing_to_do="If you think an error has occurred , please file a bug report at \" https://github.com/Antynea/grub-btrfs \"\n# Nothing to do. Abort.\n###### - Grub-btrfs: Snapshot detection ended   - ######\n"
+    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# ${nothing_to_do}" >&2 ;
+    printf "${arg}\n${nothing_to_do}" >&2 ;
-	exit 0
+    exit 0
 }
 
 test_btrfs()
 {
-	set +e
+    [[ "$root_fs" != "btrfs" ]] && print_error "Root partition isn't a btrfs filesystem.\nThis script only supports snapshots of the btrfs filesystem."
-	type btrfs >/dev/null 2>&1
+    set +e
-	if [[ $? -ne 0 ]]; then
+    type btrfs >/dev/null 2>&1
-		print_error "This script only supports snapshots of the btrfs filesystem, make sure you have btrfs-progs on your system."
+    if [[ $? -ne 0 ]]; then
-	fi
+        print_error "Unable to retrieve info from btrfs filesystem, make sure you have btrfs-progs on your system."
-	set -e
+    fi
+    set -e
 }
-##############
-### Script ###
-##############
-
 
+### Script
 ## Create entry
-entry()	{
+entry()
-echo "$@" >> "/boot/$grub_directory/grub-btrfs.cfg"
+{
-# local arg="$@"
+echo "$@" >> "$grub_directory/grub-btrfs.cfg"
-# echo "${arg}" >> "/boot/$grub_directory/grub-btrfs.cfg"
-# cat << EOF >> "/boot/$grub_directory/grub-btrfs.cfg"
-# ${arg}
-# EOF
 }
 
 ## menu entries
 make_menu_entries()
 {
 ## \" required for snap,kernels,init,microcode with space in their name
-	entry "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}"/"${k}" ]] && continue;
+        [[ ! -f "${boot_dir}"/"${k}" ]] && continue;
-		kversion=${k#*"-"}
+        kversion=${k#*"-"}
-		for i in "${name_initramfs[@]}"; do
+        for i in "${name_initramfs[@]}"; do
-			prefix_i=${i%%"-"*}
+            prefix_i=${i%%"-"*}
-			suffix_i=${i#*"-"}
+            suffix_i=${i#*"-"}
-         	alt_suffix_i=${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="${i}";
-			else 	continue ;
+            else continue ;
-			fi
+            fi
-			for u in "${name_microcode[@]}"; do
+            for u in "${name_microcode[@]}"; do
-				if [[ -f "${boot_dir}"/"${u}" && "${i}" != "${prefix_i}-${kversion}-${alt_suffix_i}" ]] ; then
+                if [[ "${name_microcode}" != "x" ]] ; then
-				entry "
+                    entry "
-	menuentry '"${k}" & "${i}" & "${u}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid'{"
+    menuentry '"${k}" & "${i}" & "${u}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid' {"
-				else
+                else
-				entry "
+                    entry "
-	menuentry '"${k}" & "${i}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid'{"
+    menuentry '"${k}" & "${i}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid' {"
-				fi
+                fi
-				entry "\
+                entry "\
-		if [ x\$feature_all_video_module = xy ]; then
+        if [ x\$feature_all_video_module = xy ]; then
-		insmod all_video
+        insmod all_video
-		fi
+        fi
-		set gfxpayload=keep
+        set gfxpayload=keep
-		insmod ${boot_fs}
+        insmod ${boot_fs}
-		if [ x\$feature_platform_search_hint = xy ]; then
+        if [ x\$feature_platform_search_hint = xy ]; then
-			search --no-floppy --fs-uuid  --set=root ${boot_hs} ${boot_uuid}
+            search --no-floppy --fs-uuid  --set=root ${boot_hs} ${boot_uuid}
-		else
+        else
-			search --no-floppy --fs-uuid  --set=root ${boot_uuid}
+            search --no-floppy --fs-uuid  --set=root ${boot_uuid}
-		fi
+        fi
-		echo 'Loading Snapshot: "${snap_date_time}" "${snap_dir_name}"'
+        echo 'Loading Snapshot: "${snap_date_time}" "${snap_dir_name}"'
-		echo 'Loading Kernel: "${k}" ...'
+        echo 'Loading Kernel: "${k}" ...'
-		linux \"${boot_dir_root_grub}/"${k}"\" root="${LINUX_ROOT_DEVICE}" rw rootflags=subvol=\""${snap_dir_name}"\" ${kernel_parameters}"
+        linux \"${boot_dir_root_grub}/"${k}"\" root="${LINUX_ROOT_DEVICE}" ${kernel_parameters} ${rootflags}subvol=\""${snap_dir_name}"\""
-				if [[ -f "${boot_dir}"/"${u}" && "${i}" != "${prefix_i}-${kversion}-${alt_suffix_i}" ]] ; then
+                if [[ "${name_microcode}" != "x" ]] ; then
-					entry "\
+                    entry "\
-		echo 'Loading Microcode & Initramfs: "${u}" "${i}" ...'
+        echo 'Loading Microcode & Initramfs: "${u}" "${i}" ...'
-		initrd \"${boot_dir_root_grub}/"${u}"\" \"${boot_dir_root_grub}/"${i}"\""
+        initrd \"${boot_dir_root_grub}/"${u}"\" \"${boot_dir_root_grub}/"${i}"\""
-				else
+                else
-					entry "\
+                    entry "\
-		echo 'Loading Initramfs: "${i}" ...'
+        echo 'Loading Initramfs: "${i}" ...'
-		initrd \"${boot_dir_root_grub}/"${i}"\""
+        initrd \"${boot_dir_root_grub}/"${i}"\""
-				fi
+                fi
-	entry "	}"
+                entry "    }"
-				count_warning_menuentries=$((1+$count_warning_menuentries))
+                count_warning_menuentries=$((1+$count_warning_menuentries))
-			done
+            done
-		done
+        done
-	done
+    done
-	entry  "}"
+    entry  "}"
 }
 
 ## 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 --no-dbus -t 0 -c "$snapper_config" list | tail -n +3 | cut -d'|' -f 1))
+        if [ -s "/etc/snapper/configs/$snapper_config" ]; then
-		local snapper_types=($(snapper --no-dbus -t 0 -c "$snapper_config" list | tail -n +3 | cut -d'|' -f 2))
+            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=($(snapper --no-dbus -t 0 -c "$snapper_config" list | tail -n +3 | rev | cut -d'|' -f 2 | rev))
+            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
+        # Discard deleted snapshots
-		if [ "$snap_path_name" = "DELETED" ]; then continue; fi
+        if [ "$snap_path_name" = "DELETED" ]; then continue; fi
-		[[ ${snap_path_name%%"/"*} == "<FS_TREE>" ]] && snap_path_name=${snap_path_name#*"/"}
+        [[ ${snap_path_name%%"/"*} == "<FS_TREE>" ]] && snap_path_name=${snap_path_name#*"/"}
 
-		# ignore specific path during run "grub-mkconfig"
+        # ignore specific path during run "grub-mkconfig"
-		if [ ! -z "${ignore_specific_path}" ] ; then
+        if [ ! -z "${GRUB_BTRFS_IGNORE_SPECIFIC_PATH}" ] ; then
-			for isp in ${ignore_specific_path[@]} ; do
+            for isp in ${GRUB_BTRFS_IGNORE_SPECIFIC_PATH[@]} ; do
-				[[ "${snap_path_name}" == "${isp}"/* ]] && continue 2;
+                [[ "${snap_path_name}" == "${isp}" ]] && continue 2;
-			done
+            done
-		fi
+        fi
+        if [ ! -z "${GRUB_BTRFS_IGNORE_PREFIX_PATH}" ] ; then
+            for isp in ${GRUB_BTRFS_IGNORE_PREFIX_PATH[@]} ; do
+                [[ "${snap_path_name}" == "${isp}"/* ]] && continue 2;
+            done
+        fi
 
-		# detect if /boot directory exists
+        # detect if /boot directory exists
-		[[ ! -d "$gbgmp/$snap_path_name/boot" ]] && continue;
+        [[ ! -d "$gbgmp/$snap_path_name/boot" ]] && continue;
 
-		local id="${snap_path_name//[!0-9]}" # brutal way to get id: remove everything non-numeric
+        local id="${snap_path_name//[!0-9]}" # brutal way to get id: remove everything non-numeric
-		ids+=("$id")
+        ids+=("$id")
 
-		local entry="${snap[@]:10:2} | ${snap_path_name}"
+        local entry="${snap[@]:10:2} | ${snap_path_name}"
-		entries+=("$entry")
+        entries+=("$entry")
 
-		# Find max length of a snapshot entry, needed for pretty formatting
+        # Find max length of a snapshot entry, needed for pretty formatting
-		local length="${#entry}"
+        local length="${#entry}"
-		[[ "$length" -gt "$max_entry_length" ]] && max_entry_length=$length
+        [[ "$length" -gt "$max_entry_length" ]] && max_entry_length=$length
-	done
+    done
 
-	# Find max length of a snapshot type, needed for pretty formatting
+    # Find max length of a snapshot type, needed for pretty formatting
-	local max_type_length=0
+    local max_type_length=0
-	for id in "${ids[@]}"; do
+    for id in "${ids[@]}"; do
-		for j in "${!snapper_ids[@]}"; do
+        for j in "${!snapper_ids[@]}"; do
-			local snapper_id="${snapper_ids[$j]//[[:space:]]/}"
+            local snapper_id="${snapper_ids[$j]//[[:space:]]/}"
-			if [[ "$snapper_id" == "$id" ]]; then
+            if [[ "$snapper_id" == "$id" ]]; then
-				local snapper_type=$(trim "${snapper_types[$j]}")
+                local snapper_type=$(trim "${snapper_types[$j]}")
-				local length="${#snapper_type}"
+                local length="${#snapper_type}"
-				[[ "$length" -gt "$max_type_length" ]] && max_type_length=$length
+                [[ "$length" -gt "$max_type_length" ]] && max_type_length=$length
-			fi
+            fi
-		done
+        done
-	done
+    done
 
-	for i in "${!entries[@]}"; do
+    for i in "${!entries[@]}"; do
-		local id="${ids[$i]}"
+        local id="${ids[$i]}"
-		local entry="${entries[$i]}"
+        local entry="${entries[$i]}"
-		for j in "${!snapper_ids[@]}"; do
+        for j in "${!snapper_ids[@]}"; do
-			local snapper_id="${snapper_ids[$j]//[[:space:]]/}"
+            local snapper_id="${snapper_ids[$j]//[[:space:]]/}"
-			# remove other non numeric characters
+            # remove other non numeric characters
-			snapper_id="${snapper_id//\*/}"
+            snapper_id="${snapper_id//\*/}"
-			snapper_id="${snapper_id//\+/}"
+            snapper_id="${snapper_id//\+/}"
-			snapper_id="${snapper_id//-/}"
+            snapper_id="${snapper_id//-/}"
-			if [[ "$snapper_id" == "$id" ]]; then
+            if [[ "$snapper_id" == "$id" ]]; then
-				local snapper_type=$(trim "${snapper_types[$j]}")
+                local snapper_type=$(trim "${snapper_types[$j]}")
-				local snapper_description=$(trim "${snapper_descriptions[$j]}")
+                local snapper_description=$(trim "${snapper_descriptions[$j]}")
-				printf -v entry "%-${max_entry_length}s | %-${max_type_length}s | %s" "$entry" "$snapper_type" "$snapper_description"
+                printf -v entry "%-${max_entry_length}s | %-${max_type_length}s | %s" "$entry" "$snapper_type" "$snapper_description"
-				break
+                break
-			fi
+            fi
-		done
+        done
-		echo "$entry"
+        echo "$entry"
-	done
+    done
 
-	IFS=$oldIFS
+    IFS=$oldIFS
 }
 
 ## Detect kernels in "/boot"
 detect_kernel()
 {
-	list_kernel=()
+    list_kernel=()
-	# Original kernel (auto-detect)
+    # Original kernel (auto-detect)
-	for okernel in	"${boot_dir}"/vmlinuz-* \
+    for okernel in  "${boot_dir}"/vmlinuz-* \
-			"${boot_dir}"/vmlinux-* \
+                    "${boot_dir}"/vmlinux-* \
-			"${boot_dir}"/kernel-* ; do
+                    "${boot_dir}"/kernel-* ; do
-		[[ ! -f "${okernel}" ]] && continue;
+        [[ ! -f "${okernel}" ]] && continue;
-		list_kernel+=("$okernel")
+        list_kernel+=("$okernel")
-	done
+    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 "${boot_dir}/${nkernel[@]}" ; do
+        for ckernel in "${boot_dir}/${GRUB_BTRFS_NKERNEL[@]}" ; do
-			[[ ! -f "${ckernel}" ]] && continue;
+            [[ ! -f "${ckernel}" ]] && continue;
-			list_kernel+=("$ckernel")
+            list_kernel+=("$ckernel")
-		done
+        done
-	fi
+    fi
 }
 
 ## Detect initramfs in "/boot"
 detect_initramfs()
 {
-	list_initramfs=()
+    list_initramfs=()
-	# Original initramfs (auto-detect)
+    # Original initramfs (auto-detect)
-	for oinitramfs in	"${boot_dir}"/initrd.img-* \
+    for oinitramfs in   "${boot_dir}"/initrd.img-* \
-				"${boot_dir}"/initrd-*.img \
+                        "${boot_dir}"/initrd-*.img \
-				"${boot_dir}"/initrd-*.gz \
+                        "${boot_dir}"/initrd-*.gz \
-				"${boot_dir}"/initramfs-*.img \
+                        "${boot_dir}"/initramfs-*.img \
-				"${boot_dir}"/initramfs-*.gz ; do
+                        "${boot_dir}"/initramfs-*.gz ; do
-		[[ ! -f "${oinitramfs}" ]] && continue;
+        [[ ! -f "${oinitramfs}" ]] && continue;
-		list_initramfs+=("$oinitramfs")
+        list_initramfs+=("$oinitramfs")
-	done
+    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 "${boot_dir}/${ninit[@]}" ; do
+        for cinitramfs in "${boot_dir}/${GRUB_BTRFS_NINIT[@]}" ; do
-			[[ ! -f "${cinitramfs}" ]] && continue;
+            [[ ! -f "${cinitramfs}" ]] && continue;
-			list_initramfs+=("$cinitramfs")
+            list_initramfs+=("$cinitramfs")
-		done
+        done
-	fi
+    fi
 }
 
 ## Detect microcode in "/boot"
 detect_microcode()
 {
-	list_ucode=()
+    list_ucode=()
-	# Original intel microcode
+    # Original intel/amd microcode (auto-detect)
-	for oiucode in "${boot_dir}"/intel-ucode.img ; do
+    # See "https://www.gnu.org/software/grub/manual/grub/html_node/Simple-configuration.html"
-		[[ ! -f "${oiucode}" ]] && continue;
+    for oiucode in  "${boot_dir}"/intel-uc.img \
-		list_ucode+=("$oiucode")
+                    "${boot_dir}"/intel-ucode.img \
-	done
+                    "${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 "${boot_dir}/${microcode[@]}" ; do
+        for cucode in "${boot_dir}/${GRUB_BTRFS_CUSTOM_MICROCODE[@]}" ; do
-			[[ ! -f "${cucode}" ]] && continue
+            [[ ! -f "${cucode}" ]] && continue
-			list_ucode+=("$cucode")
+            list_ucode+=("$cucode")
-		done
+        done
-	fi
+    fi
-	if [ -z "${list_ucode}" ]; then list_ucode=(x); fi
+    if [ -z "${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/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} ${name_snapshot}"
+        *)      title_menu="${prefixentry} ${snap_date_time} ${name_snapshot}"
-	esac
+    esac
 }
 
 ## List of kernels, initramfs and microcode in snapshots
 boot_bounded()
 {
-	# Initialize menu entries
+    # Initialize menu entries
-	IFS=$'\n'
+    IFS=$'\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 "$item" | cut -d' ' -f1-2)"
-		snap_date_time="$(echo "$item" | cut -d' ' -f1-2)"
+        snap_date_time="$(trim "$snap_date_time")"
-		snap_date_time="$(trim "$snap_date_time")"
+        
-
+        boot_dir="$gbgmp/$snap_dir_name$boot_directory"
-		boot_dir="$gbgmp/$snap_dir_name/boot"
+        # Kernel (Original + custom kernel)
-		# Kernel (Original + custom kernel)
+        detect_kernel
-		detect_kernel
+        if [ -z "${list_kernel}" ]; then continue; fi
-		if [ -z "${list_kernel}" ]; then continue; fi
+        name_kernel=("${list_kernel[@]##*"/"}")
-		name_kernel=("${list_kernel[@]##*"/"}")
+        # Detect rootflags
-		# Initramfs (Original + custom initramfs)
+        detect_rootflags
-		detect_initramfs
+        # Initramfs (Original + custom initramfs)
-		if [ -z "${list_initramfs}" ]; then continue; fi
+        detect_initramfs
-		name_initramfs=("${list_initramfs[@]##*"/"}")
+        if [ -z "${list_initramfs}" ]; then continue; fi
-		# microcode (intel-ucode + custom microcode)
+        name_initramfs=("${list_initramfs[@]##*"/"}")
-		detect_microcode
+        # microcode (auto-detect + custom microcode)
-		name_microcode=("${list_ucode[@]##*"/"}")
+        detect_microcode
-		# show snapshot found during run "grub-mkconfig"
+        name_microcode=("${list_ucode[@]##*"/"}")
-		if [[ "${show_snap_found}" = "true" ]]; then
+        # show snapshot found during run "grub-mkconfig"
-		printf $"# Found snapshot: %s\n" "$item" >&2 ;
+        if [[ "${GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND:-"true"}" = "true" ]]; then
-		fi
+            printf "Found snapshot: %s\n" "$item" >&2 ;
-		# Show full path snapshot or only name
+        fi
-		path_snapshot
+        # Show full path snapshot or only name
-		# Title format in grub-menu
+        path_snapshot
-		title_format
+        # Title format in grub-menu
-		# convert /boot directory to root of GRUB (e.g /boot become /)
+        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 menuentries
+        boot_dir_root_grub="$(make_system_path_relative_to_its_root "${boot_dir}")"
-		make_menu_entries
+        # Make menuentries
-		### Limit snapshots found during run "grub-mkconfig"
+        make_menu_entries
-	        count_limit_snap=$((1+$count_limit_snap))
+        ### Limit snapshots found during run "grub-mkconfig"
-	        [[ $count_limit_snap -ge $limit_snap_show ]] && break;
+        count_limit_snap=$((1+$count_limit_snap))
-		# Limit generation of menuentries if exceeds 250
+        [[ $count_limit_snap -ge $limit_snap_show ]] && break;
-		# [[ $count_warning_menuentries -ge 250 ]] && break;
+        # Limit generation of menuentries if exceeds 250
-	done
+        # [[ $count_warning_menuentries -ge 250 ]] && break;
-	IFS=$oldIFS
+    done
+    IFS=$oldIFS
 }
 boot_separate()
 {
-	boot_dir="/boot"
+    boot_dir="${boot_directory}"
-	# convert /boot directory to root of GRUB (e.g /boot become /)
+    # convert /boot directory to root of GRUB (e.g /boot become /)
-	boot_dir_root_grub="$(make_system_path_relative_to_its_root "${boot_dir}")"
+    boot_dir_root_grub="$(make_system_path_relative_to_its_root "${boot_dir}")"
 
-	# Kernel (Original + custom kernel)
+    # Kernel (Original + custom kernel)
-	detect_kernel
+    detect_kernel
-	if [ -z "${list_kernel}" ]; then print_error "Kernels not found."; fi
+    if [ -z "${list_kernel}" ]; then print_error "Kernels not found."; fi
-	name_kernel=("${list_kernel[@]##*"/"}")
+    name_kernel=("${list_kernel[@]##*"/"}")
+    # Initramfs (Original + custom initramfs)
+    detect_initramfs
+    if [ -z "${list_initramfs}" ]; then print_error "Initramfs not found."; fi
+    name_initramfs=("${list_initramfs[@]##*"/"}")
+    # microcode (auto-detect + custom microcode)
+    detect_microcode
+    name_microcode=("${list_ucode[@]##*"/"}")
 
-	# Initramfs (Original + custom initramfs)
+    # Initialize menu entries
-	detect_initramfs
+    IFS=$'\n'
-	if [ -z "${list_initramfs}" ]; then print_error "Initramfs not found."; fi
+    for item in $(snapshot_list); do
-	name_initramfs=("${list_initramfs[@]##*"/"}")
+        [[ ${limit_snap_show} -le 0 ]] && break; # fix: limit_snap_show=0
-
+        IFS=$oldIFS
-	# microcode (auto-detect + custom microcode)
+        snap_full_name="$(echo "$item" | cut -d'|' -f2-)" # do not trim it to keep nice formatting
-	detect_microcode
+        snap_dir_name="$(echo "$item" | cut -d'|' -f2)"
-	name_microcode=("${list_ucode[@]##*"/"}")
+        snap_dir_name="$(trim "$snap_dir_name")"
-
+        snap_date_time="$(echo "$item" | cut -d' ' -f1-2)"
-	# Initialize menu entries
+        snap_date_time="$(trim "$snap_date_time")"
-	IFS=$'\n'
+        # Detect rootflags
-	for item in $(snapshot_list); do
+        detect_rootflags
-		# fix: limit_snap_show=0
+        # show snapshot found during run "grub-mkconfig"
-		[[ ${limit_snap_show} -le 0 ]] && break;
+        if [[ "${GRUB_BTRFS_SHOW_SNAPSHOTS_FOUND:-"true"}" = "true" ]]; then
-		IFS=$oldIFS
+            printf "Found snapshot: %s\n" "$item" >&2 ;
-		snap_full_name="$(echo "$item" | cut -d'|' -f2-)" # do not trim it to keep nice formatting
+        fi
-		snap_dir_name="$(echo "$item" | cut -d'|' -f2)"
+        # Show full path snapshot or only name
-		snap_dir_name="$(trim "$snap_dir_name")"
+        path_snapshot
-		snap_date_time="$(echo "$item" | cut -d' ' -f1-2)"
+        # Title format in grub-menu
-		snap_date_time="$(trim "$snap_date_time")"
+        title_format
-		# show snapshot found during run "grub-mkconfig"
+        # Make menuentries
-		if [[ "${show_snap_found}" = "true" ]]; then
+        make_menu_entries
-		printf $"# Found snapshot: %s\n" "$item" >&2 ;
+        # Limit snapshots found during run "grub-mkconfig"
-		fi
+        count_limit_snap=$((1+$count_limit_snap))
-		# Show full path snapshot or only name
+        [[ $count_limit_snap -ge $limit_snap_show ]] && break;
-		path_snapshot
+        # Limit generation of menuentries if exceeds 250
-		# Title format in grub-menu
+        # [[ $count_warning_menuentries -ge 250 ]] && break;
-		title_format
+    done
-		# Make menuentries
+    IFS=$oldIFS
-		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 ###
+### Start
-printf "###### - Grub-btrfs: Snapshot detection started - ######\n" >&2 ;
+printf "Detecting snapshots ...\n" >&2 ;
-# if btrfs prog isn't installed, exit
+# Only support btrfs snapshots
 test_btrfs
 # Delete existing config
-#rm -f --preserve-root "/boot/$grub_directory/grub-btrfs.cfg"
+#rm -f --preserve-root "$grub_directory/grub-btrfs.cfg"
-> "/boot/$grub_directory/grub-btrfs.cfg"
+> "$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 $gbgmp/
@@ -520,37 +515,35 @@ count_limit_snap=0
 # detect uuid requirement
 check_uuid_required
 # Detects if /boot is a separate partition
-if [[ "$override_boot_partition_detection" == "true" ]]; then
+if [[ "${GRUB_BTRFS_OVERRIDE_BOOT_PARTITION_DETECTION:-"false"}" == "true" ]]; then
-	printf "# Info: Override boot partition detection : enable \n" >&2 ;
+    printf "Info: Override boot partition detection : enable \n" >&2 ;
-	boot_separate
+    boot_separate
-	else
+else
-	if [[ "$root_uuid" != "$boot_uuid" ]]; then
+    if [[ "$root_uuid" != "$boot_uuid" ]]; then
-		printf "# Info: Separate boot partition detected \n" >&2 ;
+        printf "Info: Separate boot partition detected \n" >&2 ;
-		boot_separate
+        boot_separate
-		else
+    else
-		printf "# Info: Separate boot partition not detected \n" >&2 ;
+        printf "Info: Separate boot partition not detected \n" >&2 ;
-		boot_bounded
+        boot_bounded
-	fi
+    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 ;
+[[ $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 ;
+# printf "menuentries = $count_warning_menuentries \n" >&2 ;
 # Show total found snapshots
-if [[ "${show_total_snap_found}" = "true" && ! -z "${count_limit_snap}" && "${count_limit_snap}" != "0" ]]; then
+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 ;
+    printf "Found ${count_limit_snap} snapshot(s)\n" >&2 ;
 fi
 # if no snapshot found, exit
 if [[ "${count_limit_snap}" = "0" || -z "${count_limit_snap}" ]]; then
-	print_error "No snapshots found."
+    print_error "No snapshots found."
 fi
-root_grub="$(make_system_path_relative_to_its_root /boot/$grub_directory)"
 # Make a submenu in GRUB (grub.cfg)
 cat << EOF
-submenu '${submenuname}' {
+submenu '${submenuname}' ${protection_authorized_users}${unrestricted_access_submenu}{
-	configfile "\${prefix}/grub-btrfs.cfg"
+    configfile "\${prefix}/grub-btrfs.cfg"
 }
 EOF
-printf "###### - Grub-btrfs: Snapshot detection ended   - ######\n" >&2 ;
+### End
-### End ###

Makefile

@@ -1,14 +1,71 @@
 PKGNAME ?= grub-btrfs
 PREFIX ?= /usr
 
+INITCPIO ?= false
+
 SHARE_DIR = $(DESTDIR)$(PREFIX)/share
 LIB_DIR = $(DESTDIR)$(PREFIX)/lib
 
-.PHONY: install
+.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 "$(DESTDIR)/etc/default/grub-btrfs/" config
 	@install -Dm644 -t "$(LIB_DIR)/systemd/system/" grub-btrfs.service
 	@install -Dm644 -t "$(LIB_DIR)/systemd/system/" grub-btrfs.path
 	@install -Dm644 -t "$(SHARE_DIR)/licenses/$(PKGNAME)/" LICENSE
+	@# Arch Linux like distros only :
+	@if test "$(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 "$(SHARE_DIR)/doc/$(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 "$(LIB_DIR)/systemd/system/grub-btrfs.service"
+	@rm -f "$(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 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

README.md

@@ -6,22 +6,30 @@
 This is a version 4.xx of grub-btrfs
 ##### BTC donation address: `1Lbvz244WA8xbpHek9W2Y12cakM6rDe5Rt`
 ##
-### Description
+### Description :
 Improves Grub by adding "btrfs snapshots" to the Grub menu.
 
-You can start your system on a "snapshot" from the Grub menu.
+You can boot your system on a "snapshot" from the Grub menu.  
-
 Supports manual snapshots, snapper, timeshift ...
 
-##### Warning : it isn't recommended to start on read-only snapshot
+##### 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).
+
 ##
 ### 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 microcode in "/boot" directory on snapshots.
+* Automatically Detect kernel, initramfs and intel/amd microcode in "/boot" directory on snapshots.
 * Automatically Create corresponding "menuentry" in `grub.cfg`
 * Automatically detect snapper and use snapper's snapshot description if available.
 * Automatically generate `grub.cfg` if you use the provided systemd service.
+
 ##
 ### Installation :
 #### Arch Linux
@@ -30,120 +38,65 @@ Supports manual snapshots, snapper, timeshift ...
 pacman -S grub-btrfs
 ```
 
-### Manual
+#### Manual
 
 * Run `make install` or look into Makefile for instructions on where to put each file.
 
-NOTE: Generate your Grub menu after installation for the changes to take effect.
+NOTE: Generate your Grub menu after installation for the changes to take effect.  
-
 On Arch Linux use `grub-mkconfig -o /boot/grub/grub.cfg`.
 
 ##
-### Customization:
+### Customization :
 
-You have the possibility to modify many parameters in `/etc/default/grub-btrfs/config`.
+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.
 
-* GRUB_BTRFS_SUBMENUNAME="Arch Linux Snapshots"
-
-	Name appearing in the Grub menu.
-
-* GRUB_BTRFS_PREFIXENTRY="Snapshot:"
-
-	Add a name ahead your snapshots entries in the Grub menu.
-	
-* GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT="true"
-	
-	Show full path snapshot or only name in the Grub menu, weird reaction with snapper.
-	
-* GRUB_BTRFS_TITLE_FORMAT="p/d/n"
-
- 	Custom title, shows/hides p"prefix" d"date" n"name" in the Grub menu, separator "/", custom order available.
-
-* GRUB_BTRFS_LIMIT="50"
-
-	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_NKERNEL=("kernel-custom")
-
-	Use it only if you have a custom kernel name
-
-* GRUB_BTRFS_NINIT=("initramfs-custom.img" "initrd.img-custom")
-
-	Use it only if you have a custom initramfs name.
-
-* GRUB_BTRFS_INTEL_UCODE=("intel-ucode.img")
-
-	Use it only if you have custom intel-ucode.
-
-* GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("var/lib/docker")
-
-	Ignore specific path during run "grub-mkconfig".
-	
-	For example: 
-	
-	If path is a directory `# Found Snapshot: 2016-03-31 10:24:41` **var/lib/docker/btrfs/subvolumes/...**
-	
-	use : `GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("var/lib/docker")`
-	
-	If path is a subvolume : `# Found Snapshot: 2016-03-31 10:24:41` **@var/lib/docker/btrfs/subvolumes/...**
-	
-	use : `GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("@var/lib/docker")`
-	
-	You can combine them
-	
-	use : `GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("@var/lib/docker" "var/lib/docker")`
-
-
-* GRUB_BTRFS_SNAPPER_CONFIG="root"													
-
-	Snapper's config name to use.
-
-* GRUB_BTRFS_DISABLE="false"
-
-	Disable grub-btrfs.
-
-* GRUB_BTRFS_DIRNAME="grub"
-
-	Name of the grub folder in `/boot/`, might be grub2 on some distributions.
-
-* GRUB_BTRFS_OVERRIDE_BOOT_PARTITION_DETECTION="false"
-
-	Change to "true" if you have a boot partition in a different subvolume.
-
-* GRUB_BTRFS_MKCONFIG=grub-mkconfig
-
-	Name or path of the 'grub-mkconfig' executable; might be 'grub2-mkconfig' on some distributions.
-	
 ##
 ### Automatically update grub
-If you would like Grub to automatically update when a snapshots is made or deleted:
+1- If you would like grub-btrfs menu to automatically update when a snapshot is created or deleted:
-* Mount your subvolume which contains snapshots to `/.snapshots`
+* Use `systemctl enable grub-btrfs.path`.
-* Use `systemctl start/enable grub-btrfs.path`
+  * `grub-btrfs.path` automatically (re)generates `grub-btrfs.cfg` when a modification appears in `/.snapshots` mount point (by default).
-* `grub-btrfs.path` automatically (re)generate `grub.cfg` when a modification appear in `/.snapshots`
+  * 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  
+##### 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

@@ -1,76 +1,122 @@
 #!/usr/bin/env bash
 
-# Name appearing in the Grub menu
+# Disable grub-btrfs.
-# Default: "Arch Linux snapshots"
+# 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
+# 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
+# Show full path snapshot or only name in the Grub menu, weird reaction with snapper.
 # Default: "true"
-#GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT="true"
+#GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT="false"
 
-# Custom title
+# Custom title.
-# shows/hides p"prefix" d"date" n"name" in the Grub menu, separator "/", custom order available
+# 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
+# Limit the number of snapshots populated in the GRUB menu.
 # Default: "50"
 #GRUB_BTRFS_LIMIT="50"
 
-# Sort the found subvolumes by newest first ("descending") or oldest first ("ascending") and show $GRUB_BTRFS_LIMIT first entries.
+# Sort the found subvolumes by "ogeneration" or "generation" or "path" or "rootid".
-# Default: "descending"
+# # See Sorting section to https://btrfs.wiki.kernel.org/index.php/Manpage/btrfs-subvolume#SUBCOMMAND
-#GRUB_BTRFS_SUBVOLUME_SORT="descending"
+# "-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="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"
 
-# Use only if you have custom kernel name
+# By default, "grub-btrfs" automatically detects most existing kernels.
-# Default:
+# If you have one or more custom kernels, you can add them here.
-#GRUB_BTRFS_NKERNEL=("vmlinuz-linux")
+# Default: ("")
+#GRUB_BTRFS_NKERNEL=("kernel-custom" "vmlinux-custom")
 
-# Use only if you have custom initramfs name
+# By default, "grub-btrfs" automatically detects most existing initramfs.
-# Default:
+# If you have one or more custom initramfs, you can add them here.
-#GRUB_BTRFS_NINIT=("initramfs-linux.img" "initramfs-linux-fallback.img")
+# Default: ("")
+#GRUB_BTRFS_NINIT=("initramfs-custom.img" "initrd-custom.img" "otherinit-custom.gz")
 
-# Use only if you have custom intel-ucode
+# By default, "grub-btrfs" automatically detects most existing microcodes.
-# Default:
+# If you have one or more custom microcodes, you can add them here.
-#GRUB_BTRFS_INTEL_UCODE=("intel-ucode.img")
+# 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".
-# If path is a directory, # Found Snapshot: 2016-03-31 10:24:41 var/lib/docker/btrfs/subvolumes/...
+# Only exact paths are ignored.
-# use : GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("var/lib/docker");
+# e.g : if `specific path` = @, only `@` snapshot will be ignored.
-# If path is a subvolume, # Found Snapshot: 2016-03-31 10:24:41 @var/lib/docker/btrfs/subvolumes/...
+# Default: ("@")
-# use : GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("@var/lib/docker");
+GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("@")
-# You can combine them
-# use : GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("@var/lib/docker" "var/lib/docker")
-# Default: 
-GRUB_BTRFS_IGNORE_SPECIFIC_PATH=("var/lib/docker" "@var/lib/docker")
 
+# 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"
 
-# Disable Grub-btrfs
+# 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="false"
+#GRUB_BTRFS_DISABLE_PROTECTION_SUBMENU="true"
-
-# Change to "true" if you have a boot partition in a different subvolume
-# Default: "false"
-#GRUB_BTRFS_OVERRIDE_BOOT_PARTITION_DETECTION="false"
-
-# Might be grub2 on some systems ex. /boot/grub2/...
-# Default: "grub"
-#GRUB_BTRFS_DIRNAME="grub"
-
-# Might be 'grub2-mkconfig' on some systems
-# Default: /usr/bin/grub-mkconfig
-#GRUB_BTRFS_MKCONFIG=/usr/bin/grub2-mkconfig

grub-btrfs.path

@@ -1,8 +1,12 @@
 [Unit]
 Description=Monitors for new snapshots
+DefaultDependencies=no
+Requires=\x2esnapshots.mount
+After=\x2esnapshots.mount
+BindsTo=\x2esnapshots.mount
 
 [Path]
 PathModified=/.snapshots
 
 [Install]
-WantedBy=multi-user.target
+WantedBy=\x2esnapshots.mount

grub-btrfs.service

@@ -8,4 +8,4 @@ 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=/bin/bash -c 'if [ -s "/boot/${GRUB_BTRFS_DIRNAME:-grub}/grub-btrfs.cfg" ]; then /etc/grub.d/41_snapshots-btrfs; else ${GRUB_BTRFS_MKCONFIG:-/usr/bin/grub-mkconfig} -o /boot/${GRUB_BTRFS_DIRNAME:-grub}/grub.cfg; fi'
+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.
+#