+# Append header to a D-Link M32/R32 Kernel 1 partition
+define Build/m32-r32-recovery-header-kernel1
+ $(eval header_start=$(word 1,$(1)))
+# create $@.header without the checksum
+ echo -en "$(header_start)\x00\x00" > "$@.header"
+# Calculate checksum over data area ($@) and append it to the header.
+# The checksum is the 2byte-sum over the whole data area.
+# Every overflow during the checksum calculation must increment the current checksum value by 1.
+ od -v -w2 -tu2 -An --endian little "$@" | awk '{ s+=$$1; } END { s%=65535; printf "%c%c",s%256,s/256; }' >> "$@.header"
+ echo -en "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x8D\x57\x30\x0B" >> "$@.header"
+# Byte 0-3: Erase Start 0x002C0000
+# Byte 4-7: Erase Length 0x02D00000
+# Byte 8-11: Data offset: 0x002C0000
+# Byte 12-15: Data Length: 0x02D00000
+ echo -en "\x00\x00\x2C\x00\x00\x00\xD0\x02\x00\x00\x2C\x00\x00\x00\xD0\x02" >> "$@.header"
+# Only zeros
+ echo -en "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" >> "$@.header"
+# Last 16 bytes, but without checksum
+ echo -en "\x42\x48\x02\x00\x00\x00\x08\x00\x00\x00\x00\x00\x60\x6E" >> "$@.header"
+# Calculate and append checksum: The checksum must be set so that the 2byte-sum of the whole header is 0.
+# Every overflow during the checksum calculation must increment the current checksum value by 1.
+ od -v -w2 -tu2 -An --endian little "$@.header" | awk '{s+=65535-$$1;}END{s%=65535;printf "%c%c",s%256,s/256;}' >> "$@.header"
+ cat "$@.header" "$@" > "$@.new"
+ mv "$@.new" "$@"
+ rm "$@.header"
+endef
+