ar71xx: Move OpenMesh image target validation into subfunction

The platform_check_image_openmesh function used break statements to signal
that the board name matched the image target. This worked because the
sysupgrade binary checked the image inside a loop. The break statement
stopped the loop and skipped any additional check.

Instead the check should be done without such sideeffects by simply
combining the board names and image targets. Only a mismatch should cause a
negative result for the caller and skipping of the additional checks.

Signed-off-by: Sven Eckelmann <sven.eckelmann@open-mesh.com>

target/linux/ar71xx/base-files/lib/upgrade/openmesh.sh

@@ -36,62 +36,46 @@ platform_add_ramfs_ubootenv()
 }
 append sysupgrade_pre_upgrade platform_add_ramfs_ubootenv
 
-platform_check_image_openmesh()
+platform_check_image_target_openmesh()
 {
-	local img_magic=$1
-	local img_path=$2
-	local fw_printenv=/usr/sbin/fw_printenv
-	local img_board_target= img_num_files= i=0
-	local cfg_name= kernel_name= rootfs_name=
-
-	case "$img_magic" in
-		# Combined Extended Image v1
-		43453031)
-			img_board_target=$(trim $(dd if="$img_path" bs=4 skip=1 count=8 2>/dev/null))
-			img_num_files=$(trim $(dd if="$img_path" bs=2 skip=18 count=1 2>/dev/null))
-			;;
-		*)
-			echo "Invalid image ($img_magic). Use combined extended images on this platform"
-			return 1
-			;;
-	esac
+	img_board_target="$1"
 
 	case "$img_board_target" in
 		OM2P)
-			[ "$board" = "om2p" ] && break
-			[ "$board" = "om2pv2" ] && break
-			[ "$board" = "om2p-lc" ] && break
-			[ "$board" = "om2p-hs" ] && break
-			[ "$board" = "om2p-hsv2" ] && break
+			[ "$board" = "om2p" ] && return 0
+			[ "$board" = "om2pv2" ] && return 0
+			[ "$board" = "om2p-lc" ] && return 0
+			[ "$board" = "om2p-hs" ] && return 0
+			[ "$board" = "om2p-hsv2" ] && return 0
 			echo "Invalid image board target ($img_board_target) for this platform: $board. Use the correct image for this platform"
 			return 1
 			;;
 		OM5P)
-			[ "$board" = "om5p" ] && break
-			[ "$board" = "om5p-an" ] && break
+			[ "$board" = "om5p" ] && return 0
+			[ "$board" = "om5p-an" ] && return 0
 			echo "Invalid image board target ($img_board_target) for this platform: $board. Use the correct image for this platform"
 			return 1
 			;;
 		OM5PAC)
-			[ "$board" = "om5p-ac" ] && break
-			[ "$board" = "om5p-acv2" ] && break
+			[ "$board" = "om5p-ac" ] && return 0
+			[ "$board" = "om5p-acv2" ] && return 0
 			echo "Invalid image board target ($img_board_target) for this platform: $board. Use the correct image for this platform"
 			return 1
 			;;
 		MR1750)
-			[ "$board" = "mr1750" ] && break
+			[ "$board" = "mr1750" ] && return 0
 			echo "Invalid image board target ($img_board_target) for this platform: $board. Use the correct image for this platform"
 			return 1
 			;;
 		MR600)
-			[ "$board" = "mr600" ] && break
-			[ "$board" = "mr600v2" ] && break
+			[ "$board" = "mr600" ] && return 0
+			[ "$board" = "mr600v2" ] && return 0
 			echo "Invalid image board target ($img_board_target) for this platform: $board. Use the correct image for this platform"
 			return 1
 			;;
 		MR900)
-			[ "$board" = "mr900" ] && break
-			[ "$board" = "mr900v2" ] && break
+			[ "$board" = "mr900" ] && return 0
+			[ "$board" = "mr900v2" ] && return 0
 			echo "Invalid image board target ($img_board_target) for this platform: $board. Use the correct image for this platform"
 			return 1
 			;;
@@ -100,6 +84,29 @@ platform_check_image_openmesh()
 			return 1
 			;;
 	esac
+}
+
+platform_check_image_openmesh()
+{
+	local img_magic=$1
+	local img_path=$2
+	local fw_printenv=/usr/sbin/fw_printenv
+	local img_board_target= img_num_files= i=0
+	local cfg_name= kernel_name= rootfs_name=
+
+	case "$img_magic" in
+		# Combined Extended Image v1
+		43453031)
+			img_board_target=$(trim $(dd if="$img_path" bs=4 skip=1 count=8 2>/dev/null))
+			img_num_files=$(trim $(dd if="$img_path" bs=2 skip=18 count=1 2>/dev/null))
+			;;
+		*)
+			echo "Invalid image ($img_magic). Use combined extended images on this platform"
+			return 1
+			;;
+	esac
+
+	platform_check_image_target_openmesh "$img_board_target" || return 1
 
 	[ $img_num_files -ne 3 ] && {
 		echo "Invalid number of embedded images ($img_num_files). Use the correct image for this platform"