brcm47xx: extract magics from specific upgrade images (and still reject them)

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

SVN-Revision: 43718

target/linux/brcm47xx/base-files/lib/upgrade/platform.sh

@@ -36,7 +36,23 @@ platform_check_image() {
 	local file_type=$(brcm47xx_identify "$1")
 
 	case "$file_type" in
-		"trx") return 0;;
+		"chk")
+			local header_len=$((0x$(get_magic_long_at "$1" 4)))
+			local board_id_len=$(($header_len - 40))
+			local board_id=$(dd if="$1" skip=40 bs=1 count=$board_id_len 2>/dev/null | hexdump -v -e '1/1 "%c"')
+			echo "Found CHK image with device board_id $board_id"
+			echo "Flashing CHK images in unsupported. Please use only .trx files."
+			return 1
+		;;
+		"cybertan")
+			local magic=$(dd if="$1" bs=1 count=4 2>/dev/null | hexdump -v -e '1/1 "%c"')
+			echo "Found CyberTAN image with device magic: $magic"
+			echo "Flashing CyberTAN images in unsupported. Please use only .trx files."
+			return 1
+		;;
+		"trx")
+			return 0
+		;;
 		*)
 			echo "Invalid image type. Please use only .trx files"
 			return 1