diff --git a/stm/Makefile b/stm/Makefile
index 3d2dc42302..a5d0aad8a0 100644
--- a/stm/Makefile
+++ b/stm/Makefile
@@ -3,6 +3,7 @@ FATFSSRC=fatfs
 CC3KSRC=cc3k
 PYSRC=../py
 BUILD=build
+DFU=../tools/dfu.py
 
 AS = arm-none-eabi-as
 CC = arm-none-eabi-gcc
@@ -116,7 +117,7 @@ OBJ = $(addprefix $(BUILD)/, $(SRC_C:.c=.o) $(SRC_S:.s=.o) $(PY_O) $(SRC_FATFS:.
 all: $(BUILD) $(BUILD)/flash.dfu
 
 $(BUILD)/flash.dfu: $(BUILD)/flash0.bin $(BUILD)/flash1.bin
-	python2 ~/stm/dfu/dfu.py -b 0x08000000:$(BUILD)/flash0.bin -b 0x08020000:$(BUILD)/flash1.bin $@
+	python2 $(DFU) -b 0x08000000:$(BUILD)/flash0.bin -b 0x08020000:$(BUILD)/flash1.bin $@
 
 $(BUILD)/flash0.bin: $(BUILD)/flash.elf
 	arm-none-eabi-objcopy -O binary -j .isr_vector $^ $@
diff --git a/tools/dfu.py b/tools/dfu.py
new file mode 100755
index 0000000000..875cc5c6e9
--- /dev/null
+++ b/tools/dfu.py
@@ -0,0 +1,121 @@
+#!/usr/bin/python
+
+# Written by Antonio Galea - 2010/11/18
+# Distributed under Gnu LGPL 3.0
+# see http://www.gnu.org/licenses/lgpl-3.0.txt
+
+import sys,struct,zlib,os
+from optparse import OptionParser
+
+DEFAULT_DEVICE="0x0483:0xdf11"
+
+def named(tuple,names):
+  return dict(zip(names.split(),tuple))
+def consume(fmt,data,names):
+  n = struct.calcsize(fmt)
+  return named(struct.unpack(fmt,data[:n]),names),data[n:]
+def cstring(string):
+  return string.split('\0',1)[0]
+def compute_crc(data):
+  return 0xFFFFFFFF & -zlib.crc32(data) -1
+
+def parse(file,dump_images=False):
+  print 'File: "%s"' % file
+  data = open(file,'rb').read()
+  crc = compute_crc(data[:-4])
+  prefix, data = consume('<5sBIB',data,'signature version size targets')
+  print '%(signature)s v%(version)d, image size: %(size)d, targets: %(targets)d' % prefix
+  for t in range(prefix['targets']):
+    tprefix, data  = consume('<6sBI255s2I',data,'signature altsetting named name size elements')
+    tprefix['num'] = t
+    if tprefix['named']:
+      tprefix['name'] = cstring(tprefix['name'])
+    else:
+      tprefix['name'] = ''
+    print '%(signature)s %(num)d, alt setting: %(altsetting)s, name: "%(name)s", size: %(size)d, elements: %(elements)d' % tprefix
+    tsize = tprefix['size']
+    target, data = data[:tsize], data[tsize:]
+    for e in range(tprefix['elements']):
+      eprefix, target = consume('<2I',target,'address size')
+      eprefix['num'] = e
+      print '  %(num)d, address: 0x%(address)08x, size: %(size)d' % eprefix
+      esize = eprefix['size']
+      image, target = target[:esize], target[esize:]
+      if dump_images:
+        out = '%s.target%d.image%d.bin' % (file,t,e)
+        open(out,'wb').write(image)
+        print '    DUMPED IMAGE TO "%s"' % out
+    if len(target):
+      print "target %d: PARSE ERROR" % t
+  suffix = named(struct.unpack('<4H3sBI',data[:16]),'device product vendor dfu ufd len crc')
+  print 'usb: %(vendor)04x:%(product)04x, device: 0x%(device)04x, dfu: 0x%(dfu)04x, %(ufd)s, %(len)d, 0x%(crc)08x' % suffix
+  if crc != suffix['crc']:
+    print "CRC ERROR: computed crc32 is 0x%08x" % crc
+  data = data[16:]
+  if data:
+    print "PARSE ERROR"
+
+def build(file,targets,device=DEFAULT_DEVICE):
+  data = ''
+  for t,target in enumerate(targets):
+    tdata = ''
+    for image in target:
+      tdata += struct.pack('<2I',image['address'],len(image['data']))+image['data']
+    tdata = struct.pack('<6sBI255s2I','Target',0,1,'ST...',len(tdata),len(target)) + tdata
+    data += tdata
+  data  = struct.pack('<5sBIB','DfuSe',1,len(data)+11,len(targets)) + data
+  v,d=map(lambda x: int(x,0) & 0xFFFF, device.split(':',1))
+  data += struct.pack('<4H3sB',0,d,v,0x011a,'UFD',16)
+  crc   = compute_crc(data)
+  data += struct.pack('<I',crc)
+  open(file,'wb').write(data)
+
+if __name__=="__main__":
+  usage = """
+%prog [-d|--dump] infile.dfu
+%prog {-b|--build} address:file.bin [-b address:file.bin ...] [{-D|--device}=vendor:device] outfile.dfu"""
+  parser = OptionParser(usage=usage)
+  parser.add_option("-b", "--build", action="append", dest="binfiles",
+    help="build a DFU file from given BINFILES", metavar="BINFILES")
+  parser.add_option("-D", "--device", action="store", dest="device",
+    help="build for DEVICE, defaults to %s" % DEFAULT_DEVICE, metavar="DEVICE")
+  parser.add_option("-d", "--dump", action="store_true", dest="dump_images",
+    default=False, help="dump contained images to current directory")
+  (options, args) = parser.parse_args()
+
+  if options.binfiles and len(args)==1:
+    target = []
+    for arg in options.binfiles:
+      try:
+        address,binfile = arg.split(':',1)
+      except ValueError:
+        print "Address:file couple '%s' invalid." % arg
+        sys.exit(1)
+      try:
+        address = int(address,0) & 0xFFFFFFFF
+      except ValueError:
+        print "Address %s invalid." % address
+        sys.exit(1)
+      if not os.path.isfile(binfile):
+        print "Unreadable file '%s'." % binfile
+        sys.exit(1)
+      target.append({ 'address': address, 'data': open(binfile,'rb').read() })
+    outfile = args[0]
+    device = DEFAULT_DEVICE
+    if options.device:
+      device=options.device
+    try:
+      v,d=map(lambda x: int(x,0) & 0xFFFF, device.split(':',1))
+    except:
+      print "Invalid device '%s'." % device
+      sys.exit(1)
+    build(outfile,[target],device)
+  elif len(args)==1:
+    infile = args[0]
+    if not os.path.isfile(infile):
+      print "Unreadable file '%s'." % infile
+      sys.exit(1)
+    parse(infile, dump_images=options.dump_images)
+  else:
+    parser.print_help()
+    sys.exit(1)