#!/usr/bin/python

# Written by Antonio Galea - 2010年11月18日
# 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円", 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 = b""
 for t, target in enumerate(targets):
 tdata = b""
 for image in target:
 # pad image to 8 bytes (needed at least for L476)
 pad = (8 - len(image["data"]) % 8) % 8
 image["data"] = image["data"] + bytes(bytearray(8)[0:pad])
 #
 tdata += struct.pack("<2I", image["address"], len(image["data"])) + image["data"]
 tdata = (
 struct.pack("<6sBI255s2I", b"Target", 0, 1, b"ST...", len(tdata), len(target)) + tdata
 )
 data += tdata
 data = struct.pack("<5sBIB", b"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, b"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)