Add a script to remount devices with extra rights

To be able to run updates such as apt, dpkg, grub,…

remountrw

@@ -0,0 +1,28 @@
+#!/bin/sh
+
+#	Remount some partitions with less restrictive permissions, e.g :
+#		* to be able to run updates (apt, dpkg, grub,…)
+
+if [ "$(id -u)" -eq 0 ]; then
+	# RW permissions
+	## get the mountpath list from fstab
+	for mountpath in /boot /opt /usr /var; do
+		# ensure "${mountpath}" is already mounted
+		if grep -q " ${mountpath} " /etc/mtab; then
+			mount "${mountpath}" -o remount,rw,suid,dev
+		fi
+	done
+
+	# EXEC + RW permissions
+	## get the mountpath list from fstab
+	for mountpath in /tmp /var/tmp /dev/shm; do
+		# ensure "${mountpath}" is already mounted
+		if grep -q " ${mountpath} " /etc/mtab; then
+			mount "${mountpath}" -o remount,rw,suid,dev,exec
+		fi
+	done
+else
+	sudo "${0}"
+fi
+
+exit 0