Refactor to set up checks for systemd-boot and the firmware interface

bin/nextboot

@@ -1,25 +1,80 @@
 #!/usr/bin/env bash
 
+# Pretty name for firmware interface
+biosname="Firmware Configuration" 
+
+# Check if systemd-boot is available
+bootctl is-installed &> /dev/null && sdboot=1
+
+# Check if rebooting to the firmware interface is supported
+[[ "$(bootctl reboot-to-firmware)" == "supported" ]] && fwboot=1
+
+
+picksdboot() {
+	# Usage: picksdboot <title> <prompt>
+	local entry PS3 COLUMNS
+	PS3="$2 "
+	COLUMNS=1
+
+	# Print title to stderr
+	printf "\n%s\n\n" "$1" >&2
+
+	# Put all systemd-boot loder entry confs into an array
+	mapfile -t sdbootlist < <(systemctl --boot-loader-entry=help)
+
+	# Only add the firmware interface to the list if booting to it is supported
+	[[ -v fwboot ]] && sdbootlist+=("$biosname")
+
+	select entry in "${sdbootlist[@]}"; do
+		break
+	done
+
+	printf "%s" "$entry"
+}
+
+
+pickefi() {
+	# Usage: pickefi <title> <prompt>
+	local bootnext PS3 COLUMNS
+	PS3="$2 "
+	COLUMNS=1
+
+	# Print title to stderr
+	printf "\n%s\n\n" "$1" >&2
+
+	# This one is fun
+	# mapfile splits stdin on \n to an array
+	# The sed regex looks for an asterisk in the 8th position (0 indexed),
+	#  which marks an efi boot entry as "active", so those are the only ones
+	#  we care to add to the list.
+	# It *seems* like one could put mapfile at the end of the pipeline, but
+	#  each command gets run in a subshell, so the array is lost. (ref: SC2031)
+	mapfile -t efientries < <(efibootmgr | sed -n '/.\{8\}\*/p')
+
+	# Rebooting to the firmware interface only works with systemd-boot, so only add
+	#  it to the EFI mode list if systemd-boot is available and it's supported
+	[[ -v sdboot && -v fwboot ]] && efientries+=("$biosname")
+
+	select efiselection in "${efientries[@]}"; do
+
+		# If they chose the firmware interface 
+		if [[ "$efiselection" == "$biosname" ]]; then
+			break
+		else
+			# Take only character 4-8 of the entry, which is the BOOTNUM
+			bootnext="${efiselection:4:4}"
+			break
+		fi
+	done
+
+	printf "%s" "$bootnext"
+}
 
-# The pretty name we want to give to the firmware entry
-biosname="Firmware Interface"
 
 while getopts ":en" opt; do
 	case $opt in 
 		e)
-			# This one is fun
+			efimode=1
-			# mapfile splits stdin on \n to an array
-			# The sed regex looks for an asterisk in the 8th position (0 indexed)
-			# It *seems* like one could put mapfile at the end of the pipeline, but
-			#  each command gets run in a subshell, so the array is lost. (ref: SC2031)
-			mapfile -t efientries < <(efibootmgr | sed -n '/.\{8\}\*/p')
-			PS3="EFI entry to BootNext: "
-			COLUMNS=1
-			select efiselection in "${efientries[@]}"; do
-				bootnext="${efiselection:4:4}"
-				break
-			done
-			sudo efibootmgr -q --bootnext "$bootnext"
 			;;
 		n)
 			noreboot=1
@@ -31,45 +86,66 @@ while getopts ":en" opt; do
 	esac
 done
 
+# If -e wasn't set, and systemd-boot isn't installed, fail over to efimode anyways
+if [[ ! -v efimode && ! -v sdboot ]]; then
+	echo "W: systemd-boot not installed. Choosing EFI boot entries instead..."
+	efimode=1
+fi
 
-# If we are trying to set the EFI entry, this conditional isn't useful
+# If we're in EFI mode
-if [[ -v bootnext ]]; then
+if [[ -v efimode ]]; then
-	:
+	title="Pick EFI boot entry"
-# If we aren't trying to set the EFI entry, and systemd-boot is installed
+	prompt="Entry"
-elif [[ ! -v bootnext ]] && bootctl is-installed &> /dev/null; then
+
-	# Select prompt options
+	if [[ -v noreboot ]]; then 
-	PS3="Select next boot entry: "
+		prompt="$prompt for next boot:"
-	COLUMNS=1
+	elif [[ ! -v noreboot ]]; then
-	select entry in $(systemctl --boot-loader-entry=help) "$biosname"; do
+		prompt="$prompt to boot IMMEDIATELY:"
-		if [[ "$entry" == "$biosname" ]]; then
+	else
-			sudo bootctl reboot-to-firmware true
+		echo "E: idk how you got here..."
-			break
+		exit 1
-		else
+	fi
-			sudo bootctl set-oneshot "$entry"
+
-			break
+	# Prompt for the user's choice
-		fi
+	choice="$(pickefi "$title" "$prompt")"
-	done
+	
+	# A special case to boot into firmware interface
+	if [[ "$choice" == "$biosname" ]]; then
+		sudo bootctl reboot-to-firmware true
+	elif [[ "$choice" != "$biosname" ]]; then
+		sudo efibootmgr -q --bootnext "$choice"
+	fi
+
+# If we're in systemd-boot mode
+elif [[ ! -v efimode ]]; then
+	title="Pick systemd-boot entry config"
+	prompt="Entry"
+
+	if [[ -v noreboot ]]; then
+		prompt="$prompt for next boot:"
+	elif [[ ! -v noreboot ]]; then
+		prompt="$prompt to boot IMMEDIATELY:"
+	else
+		echo "E: idk how you got here either..."
+		exit 1
+	fi
+
+	# Prompt for the user's choice
+	choice="$(picksdboot "$title" "$prompt")"
+	
+	# A special case to boot into firmware interface
+	if [[ "$choice" == "$biosname" ]]; then
+		sudo bootctl reboot-to-firmware true
+	elif [[ "$choice" != "$biosname" ]]; then
+		sudo bootctl set-oneshot "$choice"
+		# Add an option to speed past the boot menu, since we've already 
+		#  chosen the desired entry.
+		rebootopts+=("--boot-loader-menu=1")
+	fi
 else
-	# If we've made it here, then we're not trying to set the EFI entry, and 
+	echo "E: you DEFINITELY don't belong here..."
-	#  systemd-boot is not installed in the ESP, so bail.
-	echo "E: systemd-boot not installed. Exiting."
 	exit 1
 fi
 
-# If we do want to reboot now, and we aren't setting the EFI entry
+
-if [[ ! -v noreboot && ! -v bootnext ]]; then 
+[[ ! -v noreboot ]] && sudo systemctl reboot "${rebootopts[@]}"
-	# Reboot, and set a low timeout on the systemd-boot menu for next boot only
-	sudo systemctl reboot --boot-loader-menu=1 
-# If we do want to reboot now, and we are setting the EFI entry
-elif [[ ! -v noreboot && -v bootnext ]]; then
-	# Get on with it
-	sudo systemctl reboot
-# If we don't want to reboot now
-elif [[ -v noreboot ]]; then
-	echo "Next boot set."
-	exit 0
-# If things are otherwise fucked
-else
-	echo "E: You shouldn't be here..."
-	exit 1
-fi