From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Sun, 15 Mar 2015 19:51:15 +0100
Subject: ar71xx: fix model string detection on NETGEAR WNDR3700/3800/WNDRMAC

There were a few issues with the existing code to detect the model string:
* Always using the string starting with byte 56 would cut off the W of WNDR when
  the ID starts with 29763654+16+128 instead of 29763654+16+64
* The string contained garbage after the zero byte instead of cutting it off
  after the zero (which wasn't always visible using busybox tools, but could
  confuse other scripts)

diff --git a/target/linux/ar71xx/base-files/lib/ar71xx.sh b/target/linux/ar71xx/base-files/lib/ar71xx.sh
index a698ce5..0f9be69 100755
--- a/target/linux/ar71xx/base-files/lib/ar71xx.sh
+++ b/target/linux/ar71xx/base-files/lib/ar71xx.sh
@@ -37,16 +37,28 @@ wndr3700_board_detect() {
 		machine="NETGEAR WNDR3700"
 		;;
 	"33373031")
-		local model
-		model=$(ar71xx_get_mtd_offset_size_format art 56 10 %c)
-		if [ -z "$model" ] || [ "$model" = $'\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff' ]; then
+		case "$(ar71xx_get_mtd_offset_size_format art 56 10 %c)" in
+		$'\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff')
 			machine="NETGEAR WNDR3700v2"
-		elif [ -z "$model" ] || [ "$model" = $'\xff\xff\xff\xff\xff\xff\xff\xff\xffN' ]; then
+			;;
+		$'\xff\xff\xff\xff\xff\xff\xff\xff\xffN')
 			machine="NETGEAR WNDRMAC"
-		else
-			machine="NETGEAR $model"
-		fi
-		;;
+			;;
+		*)
+			# Use awk to remove everything after the first zero byte
+			model="$(ar71xx_get_mtd_offset_size_format art 41 32 %c | awk 'BEGIN{FS="[[:cntrl:]]"} {print $1; exit}')"
+			case $model in
+			'29763654+16+64'*)
+				machine="NETGEAR ${model:14}"
+				;;
+			'29763654+16+128'*)
+				machine="NETGEAR ${model:15}"
+				;;
+			*)
+				# Unknown ID
+				machine="NETGEAR $model"
+			esac
+		esac
 	esac
 
 	AR71XX_BOARD_NAME="$name"