x86_64: support sysupgrade config restore on PARTUUID mounted disks

Fix the move_config() procedure to properly find the corresponding disk if
the rootfs was mounted by PARTUUID instead of a device node.

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

SVN-Revision: 42946

target/linux/x86_64/base-files/lib/preinit/79_move_config

@@ -1,21 +1,44 @@
 #!/bin/sh
-# Copyright (C) 2012 OpenWrt.org
+# Copyright (C) 2012-2014 OpenWrt.org
 
 move_config() {
-	local rootfsdev
-	local rootfstype
+	local cmdline uuid disk dev
 
-	rootfstype="$(awk 'BEGIN { RS=" "; FS="="; } ($1 == "rootfstype") { print $2 }' < /proc/cmdline)"
-	case "$rootfstype" in
-		squashfs|jffs2)
-			rootfsdev="$(awk 'BEGIN { RS=" "; FS="="; } ($1 == "block2mtd.block2mtd") { print substr($2,1,index($2, ",")-1) }' < /proc/cmdline)";;
-		ext4)
-			rootfsdev="$(awk 'BEGIN { RS=" "; FS="="; } ($1 == "root") { print $2 }' < /proc/cmdline)";;
-	esac
+	if read cmdline < /proc/cmdline; then
+		case "$cmdline" in
+			*block2mtd=*)
+				disk="${cmdline##*block2mtd=}"
+				disk="${disk%%,*}"
+			;;
+			*root=*)
+				disk="${cmdline##*root=}"
+				disk="${disk%% *}"
+			;;
+		esac
 
-	mount -t ext4 -o rw,noatime "${rootfsdev%[0-9]}1" /mnt
-	mv -f /mnt/sysupgrade.tgz /
-	umount /mnt
+		case "$disk" in
+			PARTUUID=[a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9][a-f0-9]-02)
+				uuid="${cmdline#PARTUUID=}"
+				uuid="${uuid%-02}"
+				for disk in /dev/sd[a-z]; do
+					set -- $(dd if=$disk bs=1 skip=440 count=4 2>/dev/null | hexdump -v -e '4/1 "%02x "')
+					if [ "$4$3$2$1" = "$uuid" ]; then
+						dev="${disk}1"
+						break
+					fi
+				done
+			;;
+			/dev/*)
+				dev="${disk%[0-9]}1"
+			;;
+		esac
+	fi
+
+	if [ -n "$dev" ]; then
+		mount -t ext4 -o rw,noatime "$dev" /mnt
+		mv -f /mnt/sysupgrade.tgz /
+		umount /mnt
+	fi
 }
 
 boot_hook_add preinit_mount_root move_config