+# Create a header for a D-Link AI series recovery image and add it at the beginning of the image
+# Currently supported: AQUILA M30, EAGLE M32 and R32
+# Arguments:
+# 1: Start string of the header
+# 2: Firmware version
+# 3: Block start address
+# 4: Block length
+# 5: Device FMID
+define Build/dlink-ai-recovery-header
+ $(eval header_start=$(word 1,$(1)))
+ $(eval firmware_version=$(word 2,$(1)))
+ $(eval block_start=$(word 3,$(1)))
+ $(eval block_length=$(word 4,$(1)))
+ $(eval device_fmid=$(word 5,$(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+=$$1; } END { s%=65535; printf "%c%c",s%256,s/256; }' >> "$@.header"
+ echo -en "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00" >> "$@.header"
+ echo -en "$(firmware_version)" >> "$@.header"
+# Only one block supported: Erase start/length is identical to data start/length
+ echo -en "$(block_start)$(block_length)$(block_start)$(block_length)" >> "$@.header"
+# Only zeros
+ echo -en "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" >> "$@.header"
+# Last 16 bytes, but without checksum
+ echo -en "\x42\x48\x02\x00\x00\x00\x08\x00\x00\x00\x00\x00" >> "$@.header"
+ echo -en "$(device_fmid)" >> "$@.header"
+# Calculate and append checksum: The checksum must be set so that the 2byte-sum of the whole header is 0.
+# Every overflow during the checksum calculation must increment the current checksum value by 1.
+ od -v -w2 -tu2 -An --endian little "$@.header" | awk '{s+=65535-$$1;}END{s%=65535;printf "%c%c",s%256,s/256;}' >> "$@.header"
+ cat "$@.header" "$@" > "$@.new"
+ mv "$@.new" "$@"
+ rm "$@.header"
+endef
+
+define Build/dlink-sge-image
+ $(STAGING_DIR_HOST)/bin/dlink-sge-image $(1) $@ $@.enc
+ mv $@.enc $@
+endef
+
+define Build/edimax-header
+ $(STAGING_DIR_HOST)/bin/mkedimaximg -i $@ -o $@.new $(1)
+ @mv $@.new $@
+endef
+