diff --git a/firmware/hackrf-common.cmake b/firmware/hackrf-common.cmake
index 03c53f3f..92a098e8 100644
--- a/firmware/hackrf-common.cmake
+++ b/firmware/hackrf-common.cmake
@@ -168,12 +168,7 @@ macro(DeclareTargets)
 	add_custom_target(
 		${PROJECT_NAME}.dfu ALL
 		DEPENDS ${PROJECT_NAME}.bin
-		COMMAND rm -f _tmp.dfu _header.bin
-		COMMAND cp ${PROJECT_NAME}.bin _tmp.dfu
-		COMMAND dfu-suffix --vid=0x1fc9 --pid=0x000c --did=0x0 -s 0 -a _tmp.dfu
-		COMMAND python -c \"import os.path\; import struct\; print\('0000000: da ff ' + ' '.join\(map\(lambda s: '%02x' % ord\(s\), struct.pack\('<H', os.path.getsize\('${PROJECT_NAME}.bin'\) / 512 + 1\)\)\) + ' ff ff ff ff'\)\" | xxd -g1 -r > _header.bin
-		COMMAND cat _header.bin _tmp.dfu >${PROJECT_NAME}.dfu
-		COMMAND rm -f _tmp.dfu _header.bin
+		COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/../tools/make-dfu.py ${PROJECT_NAME}.bin ${PROJECT_NAME}.dfu
 	)
 
 	add_custom_target(
diff --git a/firmware/tools/make-dfu.py b/firmware/tools/make-dfu.py
new file mode 100755
index 00000000..81e1540e
--- /dev/null
+++ b/firmware/tools/make-dfu.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python2
+# vim: set ts=4 sw=4 tw=0 et pm=:
+import struct
+import sys
+import os.path
+import getopt
+import zlib
+
+options, remainder = getopt.getopt(sys.argv[1:], 'p:v:d:S:v', ['pid=',
+														'vid=',
+														'did=',
+														'spec=',
+														'verbose',
+														])
+
+pid = 0x000c
+vid = 0x1fc9
+did = 0
+spec = 0x0100
+verbose = False
+
+for opt, arg in options:
+	if opt in ('-p', '--pid'):
+		pid = int(arg)
+	if opt in ('-v', '--vid'):
+		vid = int(arg)
+	if opt in ('-d', '--did'):
+		did = int(arg)
+	if opt in ('-S', '--spec'):
+		spec = int(arg)
+	elif opt in ('-v', '--verbose'):
+		verbose = True
+
+if len(remainder)<1:
+	in_file = "/dev/stdin"
+else:
+	in_file = remainder[0]
+
+if len(remainder)<2:
+	out = open("/dev/stdout","wb")
+else:
+	out = open(remainder[1],"wb")
+
+# ref. NXP UM10503 Table 24 (Boot image header description)
+header = ""
+header += struct.pack ('<B',int("11"+"011010",2)) # AES enc not active + No hash active
+header += struct.pack ('<B',int("11"+"111111",2)) # RESERVED + AES_CONTROL
+size=os.path.getsize(in_file)
+size=(size+511)/512 # 512 byte blocks, rounded up
+header += struct.pack('<H',size)                  # (badly named) HASH_SIZE
+header += struct.pack('8B',*[0xff] *8)            # HASH_VALUE (unused)
+header += struct.pack('4B',*[0xff] *4)            # RESERVED
+
+out.write( header )
+
+infile=open(in_file,"rb").read()
+out.write( infile )
+
+suffix= ""
+suffix+= struct.pack('<H', did)  # bcdDevice
+suffix+= struct.pack('<H', pid)  # idProduct
+suffix+= struct.pack('<H', vid)  # idVendor
+suffix+= struct.pack('<H', spec) # bcdDFU
+suffix+= b'DFU'[::-1]            # (reverse DFU)
+suffix+= struct.pack('<B', 16)   # suffix length
+
+out.write( suffix )
+
+checksum=zlib.crc32(header+infile+suffix) & 0xffffffff ^ 0xffffffff
+out.write( struct.pack('I', checksum) ) # crc32