#!/usr/bin/env python # # Copyright 2020 Espressif Systems (Shanghai) PTE LTD # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # # This program creates archives compatible with ESP32-S* ROM DFU implementation. # # The archives are in CPIO format. Each file which needs to be flashed is added to the archive # as a separate file. In addition to that, a special index file, 'dfuinfo0.dat', is created. # This file must be the first one in the archive. It contains binary structures describing each # subsequent file (for example, where the file needs to be flashed/loaded). import argparse import hashlib import json import os import struct import zlib from collections import namedtuple from future.utils import iteritems try: import typing except ImportError: # Only used for type annotations pass try: from itertools import izip as zip # type: ignore except ImportError: # Python 3 pass # CPIO ("new ASCII") format related things CPIO_MAGIC = b'070701' CPIO_STRUCT = b'=6s' + b'8s' * 13 CPIOHeader = namedtuple( 'CPIOHeader', [ 'magic', 'ino', 'mode', 'uid', 'gid', 'nlink', 'mtime', 'filesize', 'devmajor', 'devminor', 'rdevmajor', 'rdevminor', 'namesize', 'check', ], ) CPIO_TRAILER = 'TRAILER!!!' def make_cpio_header( filename_len, file_len, is_trailer=False ): # type: (int, int, bool) -> CPIOHeader """ Returns CPIOHeader for the given file name and file size """ def as_hex(val): # type: (int) -> bytes return '{:08x}'.format(val).encode('ascii') hex_0 = as_hex(0) mode = hex_0 if is_trailer else as_hex(0o0100644) nlink = as_hex(1) if is_trailer else hex_0 return CPIOHeader( magic=CPIO_MAGIC, ino=hex_0, mode=mode, uid=hex_0, gid=hex_0, nlink=nlink, mtime=hex_0, filesize=as_hex(file_len), devmajor=hex_0, devminor=hex_0, rdevmajor=hex_0, rdevminor=hex_0, namesize=as_hex(filename_len), check=hex_0, ) # DFU format related things # Structure of one entry in dfuinfo0.dat DFUINFO_STRUCT = b' int """ Calculate CRC32/JAMCRC of data, with an optional initial value """ uint32_max = 0xFFFFFFFF return uint32_max - (zlib.crc32(data, crc) & uint32_max) def pad_bytes(b, multiple, padding=b'\x00'): # type: (bytes, int, bytes) -> bytes """ Pad 'b' to a length divisible by 'multiple' """ padded_len = (len(b) + multiple - 1) // multiple * multiple return b + padding * (padded_len - len(b)) class EspDfuWriter(object): def __init__(self, dest_file, pid): # type: (typing.BinaryIO, int) -> None self.dest = dest_file self.pid = pid self.entries = [] # type: typing.List[bytes] self.index = [] # type: typing.List[DFUInfo] def add_file(self, flash_addr, path): # type: (int, str) -> None """ Add file to be written into flash at given address """ with open(path, 'rb') as f: self._add_cpio_flash_entry(os.path.basename(path), flash_addr, f.read()) def finish(self): # type: () -> None """ Write DFU file """ # Prepare and add dfuinfo0.dat file dfuinfo = b''.join([struct.pack(DFUINFO_STRUCT, *item) for item in self.index]) self._add_cpio_entry(DFUINFO_FILE, dfuinfo, first=True) # Add CPIO archive trailer self._add_cpio_entry(CPIO_TRAILER, b'', trailer=True) # Combine all the entries and pad the file out_data = b''.join(self.entries) cpio_block_size = 10240 out_data = pad_bytes(out_data, cpio_block_size) # Add DFU suffix and CRC dfu_suffix = DFUSuffix(0xFFFF, self.pid, ESPRESSIF_VID, 0x0100, b'UFD', 16) out_data += struct.pack(DFUSUFFIX_STRUCT, *dfu_suffix) out_data += struct.pack(DFUCRC_STRUCT, dfu_crc(out_data)) # Finally write the entire binary self.dest.write(out_data) def _add_cpio_flash_entry( self, filename, flash_addr, data ): # type: (str, int, bytes) -> None md5 = hashlib.md5() md5.update(data) self.index.append( DFUInfo( address=flash_addr, flags=0, name=filename.encode('utf-8'), md5=md5.digest(), ) ) self._add_cpio_entry(filename, data) def _add_cpio_entry( self, filename, data, first=False, trailer=False ): # type: (str, bytes, bool, bool) -> None filename_b = filename.encode('utf-8') + b'\x00' cpio_header = make_cpio_header(len(filename_b), len(data), is_trailer=trailer) entry = pad_bytes( struct.pack(CPIO_STRUCT, *cpio_header) + filename_b, 4 ) + pad_bytes(data, 4) if not first: self.entries.append(entry) else: self.entries.insert(0, entry) def action_write(args): # type: (typing.Mapping[str, typing.Any]) -> None writer = EspDfuWriter(args['output_file'], args['pid']) for addr, f in args['files']: print('Adding {} at {:#x}'.format(f, addr)) writer.add_file(addr, f) writer.finish() print('"{}" has been written. You may proceed with DFU flashing.'.format(args['output_file'].name)) def main(): # type: () -> None parser = argparse.ArgumentParser() # Provision to add "info" command subparsers = parser.add_subparsers(dest='command') write_parser = subparsers.add_parser('write') write_parser.add_argument('-o', '--output-file', help='Filename for storing the output DFU image', required=True, type=argparse.FileType('wb')) write_parser.add_argument('--pid', required=True, type=lambda h: int(h, 16), help='Hexa-decimal product indentificator') write_parser.add_argument('--json', help='Optional file for loading "flash_files" dictionary with
items') write_parser.add_argument('files', metavar='
', help='Add at
', nargs='*') args = parser.parse_args() def check_file(file_name): # type: (str) -> str if not os.path.isfile(file_name): raise RuntimeError('{} is not a regular file!'.format(file_name)) return file_name files = [] if args.files: files += [(int(addr, 0), check_file(f_name)) for addr, f_name in zip(args.files[::2], args.files[1::2])] if args.json: json_dir = os.path.dirname(os.path.abspath(args.json)) def process_json_file(path): # type: (str) -> str ''' The input path is relative to json_dir. This function makes it relative to the current working directory. ''' return check_file(os.path.relpath(os.path.join(json_dir, path), start=os.curdir)) with open(args.json) as f: files += [(int(addr, 0), process_json_file(f_name)) for addr, f_name in iteritems(json.load(f)['flash_files'])] files = sorted([(addr, f_name) for addr, f_name in iteritems(dict(files))], key=lambda x: x[0]) # remove possible duplicates and sort based on the address cmd_args = {'output_file': args.output_file, 'files': files, 'pid': args.pid, } {'write': action_write }[args.command](cmd_args) if __name__ == '__main__': main()