Add support for root device being set using PARTUUID.

debian/changelog

+flash-kernel (3.69) UNRELEASED; urgency=medium
+
+  * Add support for root device being set using PARTUUID.
+
+ -- Vagrant Cascadian <vagrant@debian.org>  Sun, 18 Sep 2016 21:12:51 -0700
+
 flash-kernel (3.68) unstable; urgency=medium
 
   [ Karsten Merker ]

initramfs-tools/hooks/flash_kernel_set_root

@@ -67,7 +67,7 @@ if [ -n "$rootdev" ]; then
 	fi
 fi
 
-# Translate LABEL and UUID entries into a proper device name.
+# Translate LABEL, UUID, and PARTUUID entries into a proper device name.
 if echo "$rootdev" | grep -q "="; then
 	a=$(echo "$rootdev" | cut -d "=" -f 1)
 	b=$(echo "$rootdev" | cut -d "=" -f 2- | sed -e 's/^"\(.*\)"$/\1/')
@@ -86,6 +86,12 @@ if echo "$rootdev" | grep -q "="; then
 				echo "UUID $b doesn't exist in /dev/disk/by-uuid" >&2
 			fi
 		;;
+		PARTUUID)
+			rootdev=/dev/disk/by-partuuid/$b
+			if [ ! -e $rootdev ]; then
+				echo "UUID $b doesn't exist in /dev/disk/by-uuid" >&2
+			fi
+		;;
 		*)
 			echo "/etc/fstab parse error; cannot recognize root $rootdev" >&2
 			rootdev=/dev/sda2