Merge pull request #22 from anyc/master

Create only entries with matching version numbers and one small improvement

41_snapshots-btrfs

@@ -1,117 +1,416 @@
-#! /bin/sh
+#! /usr/bin/env bash
+#
+#
+#################################################################################################################################################
+# Written by: Antynea																#
+#																		#
+# Purpose: Include btrfs snapshots at boot options (grub-menu).											#
+#																		#
+# 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. (For custon name, see below.)			#
+# - Automatically Create corresponding "menuentry" in grub.cfg , which ensures a very easy rollback.						#
+#																		#
+# How to use it:																#
+# - Add this lines to /etc/default/grub:													#
+#																		#
+# * GRUB_BTRFS_SUBMENUNAME="ArchLinux 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)											#
+# * 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="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 of snapshots found during run "grub-mkconfig")										#
+# * GRUB_BTRFS_NKERNEL=("vmlinuz-linux") 		 											#
+#	(Use only if you have custom kernel name or auto-detect failed.)									#
+# * 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" "nosapshot")										#
+#	(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)				#
+#																		#
+# - Generate grub.cfg (on Archlinux 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)					#
+#																		#
+#																		#
+# To do:																	#
+#																		#
+#	* Display name of microcode in menuentry when available											#
+#																		#
+#################################################################################################################################################
+
 set -e
 
-. /usr/share/grub/grub-mkconfig_lib
-. /etc/default/grub
+#prefix="/usr"
+#exec_prefix="${prefix}"
+datarootdir="/usr/share"
+#datadir="${datarootdir}"
+sysconfdir="/etc"
 
-### variables modifiable ###
-## fr: nom du sous-menu 
-## en: Name of the submenu
-submenuname="ArchLinux Snapshots"
-## fr: préfixe de l'entrée 
-## en: Prefix entry
-prefixentry="Snapshot"
-## fr: nom(s) du ou des kernel(s)
-## en: Name(s) of the kernel(s)
-nkernel=("vmlinuz-linux")
-## fr: nom(s) de(s) l'init
-## en: Name(s) of the init(s)
-ninit=("initramfs-linux.img" "initramfs-linux-fallback.img")
+. "${datarootdir}/grub/grub-mkconfig_lib"
+. "${sysconfdir}/default/grub"
+
+######################################
+### Variables in /etc/default/grub ###
+######################################
+## Submenu name
+submenuname=${GRUB_BTRFS_SUBMENUNAME:-"ArchLinux Snapshots"}
+## Prefix entry
+prefixentry=${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=("${GRUB_BTRFS_INTEL_UCODE[@]}")
+## Limit to show in the Grub menu
+limit_snap_show="${GRUB_BTRFS_LIMIT:-100}"
+## How to sort snapshots list
+snap_list_sort=${GRUB_BTRFS_SUBVOLUME_SORT:-"descending"}
+case "${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=("${GRUB_BTRFS_IGNORE_SPECIFIC_PATH[@]}")
+## create only entries with harmonized version numbers
+harmonized_entries=${GRUB_BTRFS_CREATE_ONLY_HARMONIZED_ENTRIES:-"false"}
 
 
-###########################
-### fr: DÉBUT DU SCRIPT ###
-### en: NAME OF SCRIPT  ###
-### fr: NE PAS TOUCHER  ###
-### en: DO NOT TOUCH    ###
-###########################
-## fr: internationalisation
-## en: Internationalization
+########################
+### variables script ###
+########################
+## Internationalization (default : english)
 export TEXTDOMAIN=grub-btrfs-git
 export TEXTDOMAINDIR="/usr/share/locale"
-## fr: paramêtre des chaînes --hint
-## en: Parameter of the chains --hint (Translation unclear)
-pboot=$(${grub_probe} --target="hints_string" "/boot" 2>/dev/null)
-## fr: uuid de la partition root
-## en: UUID of the root partition
-uuid=$(${grub_probe} "/" --target="fs_uuid" 2>/dev/null)
-## fr: uuid de la partition boot
-## en: UUID of the boot partition
-buuid=$(${grub_probe} --target="fs_uuid" "/boot" 2>/dev/null)
-## fr: paramêtre passé au kernel
-## en: Parameters passed to the kernel
-params="$GRUB_CMDLINE_LINUX $GRUB_CMDLINE_LINUX_DEFAULT"
+## hints string
+hs_boot=$(${grub_probe} --target="hints_string" "/boot" 2>/dev/null)
+## UUID of the boot partition
+boot_uuid=$(${grub_probe} --target="fs_uuid" "/boot" 2>/dev/null)
+## Type filesystem of boot partition
+boot_fs=$(${grub_probe} --target="fs" "/boot" 2>/dev/null)
+## UUID of the root partition
+root_uuid=$(${grub_probe} "/" --target="fs_uuid" 2>/dev/null)
+## Parameters passed to the kernel
+kernel_parameters="$GRUB_CMDLINE_LINUX $GRUB_CMDLINE_LINUX_DEFAULT"
+## Mount point location
+gbgmp=$(mktemp -d)
+## Class for theme
+CLASS="--class snapshots --class gnu-linux --class gnu --class os"
+## save IFS
+oldIFS=$IFS
+## boot_dir (auto-detect if /boot is separate partition or not)
+boot_dir()
+{
+	boot_dir="$gbgmp/$snap_dir_name/boot"
+	[[ "$root_uuid" != "$boot_uuid" ]] && boot_dir="/boot"
+	echo "$boot_dir"
+}
 
 
-# fr: on affiche le menu
-# en: Display the menu
-echo "submenu '$submenuname' {"
+##############
+### Script ###
+##############
 
-# fr: on traite la variable kernel
-# en: Treat the kernel variables (Translation unclear)
-for kernel in ${nkernel[@]}; do
-	# fr: on test si le(s) nom(s) du(des) kernel existe(nt), autrement on affiche une erreur et on sort
-	# en: Check the specified kernel(s) exist, if it/they don't, display an error and exit
-	if [ ! -f /boot/$kernel ]; then gettext_printf $"Error: /boot/$kernel, kernel does not exist" >&2; exit 1; fi
-	# fr: on vérifie le nombre de kernel présent, si >1 on crée un menu
-	# en: If there are >1 kernels, create a menu
-	if [ ${#nkernel[*]} != 1 ]; then echo "	submenu '$kernel' {
-		submenu '---> Kernel: $kernel <---' { echo }"; fi
-	
-	# fr: On liste les snapshots présent sur le système de fichier
-	# en: List filesystem snapshots
-	for item in $($bindir/btrfs subvolume list -s / --sort=-ogen | $bindir/awk '{print $NF}'); do
-		# fr: On écarte les snapshots avec un statut de suppression
-		# en: Discard deleted snapshots
-		if [ $item = "DELETED" ]; then continue; fi
-		# fr: affiche la liste des snapshots trouvés
-		# en: Output name of snapshot
-		gettext_printf $"Found Snapshot: %s\n" "$item" >&2
-		# fr: on crée un menu pour chaque snapshot présent (nom + date de création)
-		# en: Create a menu for remaining snapshots (name + creation date)
-		date_time=$($bindir/btrfs subvolume list -s / | $bindir/grep $item | $bindir/cut -d" " -f 11-12)
-		echo "		submenu '$prefixentry $item [$date_time]' {"
-		# fr: si plusieurs kernel on été trouvé, on affiche un titre indicatif
-		# en: if more than one kernel is found, create a menu
-		if [ ${#nkernel[*]} != 1 ]; then echo "			submenu '---> Kernel: $kernel <---' { echo }"; fi
-		# fr: on traite la variable de l'initramfs
-		# en: Treat the initramfs variables (Translation unclear)
-		for init in ${ninit[@]}; do
-			# fr: on test si le(s) nom(s) du(des) initramfs existe(nt), autrement on affiche une erreur et on sort
-			# en: Check the specified initramfs(es) exist, if it/they don't, display an error and exit
-			if [ ! -f /boot/$init ]; then gettext_printf $"Error: /boot/$init, initramfs does not exist" >&2; exit 1; fi
-			# fr: on traite chaque entrée des snapshots avec leurs kernel et initramfs respectifs
-			# en: Specify a kernel and initramfs for every snapshot
+### BEGIN auto detect ###
+
+## menu entries
+snapshots_entry()
+{
+## \" required for snap,kernels,init,microcode with space in their name
+	echo "	submenu '"${title_menu[*]}"' {
+		submenu '---> "${title_menu[*]}" <---' { echo }
+	"
+	for k in "${name_kernel[@]}"; do
+		for i in "${name_initramfs[@]}"; do
+			for u in "${name_microcode[@]}"; do
 			echo "\
-			menuentry '$item $init' --class arch --class gnu-linux --class gnu --class os "\$menuentry_id_option" 'gnulinux-snapshots-$uuid'{
-				load_video
-				set gfxpayload=$GRUB_GFXPAYLOAD_LINUX
-				if [ x"\$feature_platform_search_hint" = xy ]; then
-					search --no-floppy --fs-uuid --set=root $pboot $buuid
-				else
-					search --no-floppy --fs-uuid --set=root $buuid
-				fi
-				echo	'Loading Linux snapshot ...'"
-				# fr: on vérifie l'emplacement de la partition /boot
-				# en: Check the location of the /boot partition
-				if [ $uuid = $buuid ]; then
-					echo "\
-				linux	/$item/boot/$kernel root=UUID=$uuid rw rootflags=subvol=$item $params
-				echo    'Loading initial ramdisk ...'
-				initrd	/$item/boot/$init"
-				else
-					echo "\
-				linux	/$kernel root=UUID=$uuid rw rootflags=subvol=$item $params
-				echo    'Loading initial ramdisk ...'
-				initrd  /$init"
-				fi
+		menuentry '"${k}" & "${i}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid'{
+			$(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)"/"${u}" ] ; then
 				echo "\
-			}"
+			echo 'Loading Microcode & Initramfs: "${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
+		echo "		}"
+			done
 		done
+	done
+	echo "	}"
+}
+
+harmonized_snapshots_entry()
+{
+## \" required for snap,kernels,init,microcode with space in their name
+	echo "	submenu '"${title_menu[*]}"' {
+		submenu '---> "${title_menu[*]}" <---' { echo }
+	"
+	for k in "${name_kernel[@]}"; do
+		version=${k#vmlinuz-}
+		
+		i=""
+		if [[ -e "$(boot_dir)"/initramfs-${version} ]]; then
+			i=initramfs-${version}
+		else
+			if [[ -e "$(boot_dir)"/initrd.img-${version} ]]; then
+				i=initrd.img-${version}
+			fi
+		fi
+		
+		u=""
+		if [ -f "$(boot_dir)"/intel-ucode.img ]; then
+			u=intel-ucode.img
+		fi
+		
+		
+		echo "\
+		menuentry '"${k}"' ${CLASS} "\$menuentry_id_option" 'gnulinux-snapshots-$boot_uuid'{
+			$(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 [[ ! -z ${i} ]]; then
+				if [ ! -z ${u} ] ; then
+					echo "\
+			echo 'Loading Microcode & Initramfs: "${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
-	# fr: on oubli pas de fermer le menu si plusieurs kernels ont été trouvé
-	# en: Don't forget to close menus if more than one kernel is found
-	if [ ${#nkernel[*]} != 1 ]; then echo "	}"; fi
-done
-echo "}"
+	echo "	}"
+}
+
+## List of snapshots on filesystem
+snapshot_list()
+{
+	for snap in $(btrfs subvolume list -sa "${btrfssubvolsort}" /); do
+		IFS=$oldIFS
+		snap=($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#*"/"}
+		echo ${snap[@]:10:2} ${snap_path_name}
+	done
+}
+
+## Detect kernels in "/boot"
+detect_kernel()
+{
+	## Arch original kernel (auto-detect)
+	for akernel in "$(boot_dir)"/vmlinuz-* ; do 
+		list_kernel+=("$akernel")
+	done
+
+	## Custom name kernel in GRUB_BTRFS_NKERNEL
+	if [ ! -z "${nkernel}" ] ; then
+		for ckernel in "${nkernel[@]}" ; do
+			[[ ! -f /"$(boot_dir)"/"${ckernel}" ]] && continue;
+			list_kernel+=("$ckernel")
+		done
+	fi
+}
+
+## Detect initramfs in "/boot"
+detect_initramfs()
+{
+	## Arch original initramfs (auto-detect)
+	for ainitramfs in "$(boot_dir)"/initramfs-* ; do 
+		list_initramfs+=("$ainitramfs")
+	done
+	
+	## Custom name initramfs in GRUB_BTRFS_NINIT
+	if [ ! -z "$ninit" ] ; then
+		for cinitramfs in "${ninit[@]}" ; do
+			[[ ! -f /"$(boot_dir)"/"${cinitramfs}" ]] && continue;
+			list_initramfs+=("$cinitramfs")
+		done
+	fi
+}
+
+## Detect microcode in "/boot"
+detect_microcode()
+{
+	## Arch original intel microcode
+	for aucode in "$(boot_dir)"/intel-ucode.img ; do
+		list_ucode+=("$aucode")
+	done
+
+	## Custom name microcode in GRUB_BTRFS_INTEL_UCODE
+	if [ ! -z "$microcode" ] ; then
+		for cucode in "${microcode[@]}" ; do
+			[[ ! -f /"$(boot_dir)"/"${cucode}" ]] && continue
+			list_ucode+=("$cucode")
+		done
+	fi
+}
+
+## Show full path snapshot or only name
+path_snapshot()
+{
+	case "${path_snapshot}" in
+		true) name_snapshot=("${snap_dir_name}");;
+		*) name_snapshot=("${snap_dir_name#*"/"}")
+	esac
+}
+
+## Title format in grub-menu
+title_format()
+{
+	case "${title_format}" in
+		p/d/n) 	title_menu=("${prefixentry}" "${snap_date_time}" "${name_snapshot}");;
+		p/n/d) 	title_menu=("${prefixentry}" "${snap_dir_name}" "${snap_date_time}");;
+		p/d) 	title_menu=("${prefixentry}" "${snap_date_time}");;
+		p/n) 	title_menu=("${prefixentry}" "${snap_dir_name}");;
+		d/n) 	title_menu=("${snap_date_time}" "${snap_dir_name}");;
+		n/d) 	title_menu=("${snap_dir_name}" "${snap_date_time}");;
+		p) 	title_menu=("${prefixentry}");;
+		d)	title_menu=("${snap_date_time}");;
+		n)	title_menu=("${snap_dir_name}");;
+		*)	gettext_printf $"# Warning: GRUB_BTRFS_TITLE_FORMAT=${title_format}, syntax error \n" >&2
+	esac
+}
+
+## List of kernels, initramfs and microcode in snapshots
+list_kernels_initramfs()
+{
+	IFS=$'\n'
+	count_limit_snap=0
+	for item in $(snapshot_list); do
+		### fix: limit_snap_show=0
+		[[ ${limit_snap_show} -le 0 ]] && break;
+		IFS=$oldIFS
+		item=($item)
+		snap_dir_name=${item[@]:2:${#item[@]}}
+		### ignore specific path during run "grub-mkconfig"
+		if [ ! -z "${ignore_specific_path}" ] ; then
+			for isp in ${ignore_specific_path[@]} ; do
+				[[ "${gbgmp}"/"${snap_dir_name}" == "${gbgmp}"/"${isp}"/* ]] && continue 2;
+			done
+		fi
+		### detect if /boot directory exist
+		[[ ! -d "$gbgmp/$snap_dir_name/boot" ]] && continue;
+		### show snapshot found during run "grub-mkconfig"
+		snap_date_time=${item[@]:0:2}
+		if [[ "${show_snap_found}" = "true" ]]; then
+		gettext_printf $"# Found Snapshot: %s\n" "${snap_date_time} ${snap_dir_name}" >&2 ;
+		fi
+		### Kernel (auto-detect + custom kernel)
+		unset list_kernel
+		detect_kernel
+		name_kernel=("${list_kernel[@]##*"/"}")
+		# echo "kernel = ${name_kernel[*]}"
+		
+		if [[ "${harmonized_entries}" = "false" ]]; then
+			### Initramfs (autodetect + custom initramfs)
+			unset list_initramfs
+			detect_initramfs
+			name_initramfs=("${list_initramfs[@]##*"/"}")
+			# echo "initramfs = ${name_initramfs[*]}"
+			### microcode (auto-detect + custom microcode)
+			unset list_ucode
+			detect_microcode
+			name_microcode=("${list_ucode[@]##*"/"}")
+			# echo "ucode = ${name_microcode[*]}"
+		fi
+		### real path to boot
+		boot_dir_real_path="$(make_system_path_relative_to_its_root "$(boot_dir)")"
+		### Create menu entries
+		## name snpashot
+		path_snapshot
+		## title menu custom
+		title_format
+		# echo "${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 ###
+
+### Start ###
+	gettext_printf "###### - Grub-btrfs: Auto-detect Start - ######\n" >&2 ;
+	### create mount point and mounts
+	[[ ! -d $gbgmp ]] && mkdir -p $gbgmp
+	mount -o subvolid=0 /dev/disk/by-uuid/$root_uuid $gbgmp/
+	### Create a menu in grub
+	echo "submenu '${submenuname}' {"
+	list_kernels_initramfs ;
+	## show total found snapshots
+	if [[ "${show_total_snap_found}" = "true" ]]; then
+	gettext_printf "# found ${count_limit_snap} snapshot(s)\n" >&2 ;
+	fi
+	## if no snapshot found, show a warning 
+	if [[ "${count_limit_snap}" = "0" ]]; then
+		echo " submenu '---> "No snapshot found : Press ESC to return previous menu" <---' { echo } ";
+		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 ;
+	fi
+	echo "}"
+	## unmount mount point
+	umount $gbgmp
+	gettext_printf "###### - Grub-btrfs: Auto-detect End   - ######\n" >&2 ;
+### End ###

README.md

@@ -1,4 +1,95 @@
-grub-btrfs
-==========
+[![GitHub release](https://img.shields.io/github/release/Antynea/grub-btrfs.svg)](https://github.com/Antynea/grub-btrfs)
+  
+### grub-btrfs
 
-grub-btrfs, add support for btrfs snapshots into grub menu
+
+This is a version 1.xx of grub-btrfs
+
+#### Description
+
+grub-btrfs, Include btrfs snapshots at boot options. (grub menu)
+
+#### What does grub-btrfs v1.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 microcode in "/boot" directory on snapshots. (For custom name, see below.)
+
+* Automatically Create corresponding "menuentry" in grub.cfg , which ensures a very easy rollback.
+
+
+#### How to use it:
+
+Add this lines to /etc/default/grub:
+
+* GRUB_BTRFS_SUBMENUNAME="ArchLinux Snapshots"
+
+	(Name menu appearing in grub.)
+
+* GRUB_BTRFS_PREFIXENTRY="Snapshot:"
+
+	(Add a name ahead your snapshots entries.)
+	
+* GRUB_BTRFS_DISPLAY_PATH_SNAPSHOT="true"
+	
+	(Show full path snapshot or only name)
+	
+* 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")
+
+
+
+
+Generate grub.cfg (on Archlinux use grub-mkconfig -o /boot/grub/grub.cfg )
+
+grub-btrfs automatically generates snapshots entries.
+
+You will see it appear differents entries (e.g : Snapshot: [2014-02-12 11:24:37] my snapshot name overkill )
+
+
+#### TO DO
+
+* Display name of microcode in menuentry when available
+
+
+## discussion
+Pour les francophones : https://forums.archlinux.fr/viewtopic.php?f=18&t=17177