scripts/cameo-imghdr.py

   1 #!/usr/bin/python3
   2 # SPDX-License-Identifier: GPL-2.0-or-later
   3 #
   4 # Copyright (C) 2022 Luiz Angelo Daros de Luca <luizluca@gmail.com>
   5 #
   6 # Cameo Image header geneator, used by some D-Link DGS-1210 switches
   7 # and APRESIA ApresiaLightGS series
   8 #
   9 import argparse
  10 import pathlib
  11 import socket
  12 import struct
  13
  14 MODEL_LEN = 20
  15 SIGNATURE_LEN = 16
  16 LINUXLOAD_LEN = 10
  17 BUFSIZE = 4096
  18
  19 parser = argparse.ArgumentParser(description='Generate Cameo firmware header.')
  20 parser.add_argument('source_file', type=argparse.FileType('rb'))
  21 parser.add_argument('dest_file', type=argparse.FileType('wb'))
  22 parser.add_argument('model')
  23 parser.add_argument('signature')
  24 parser.add_argument('partition', type=int, choices=range(0,10),
  25                     metavar="partition=[0-9]",help="partition id")
  26 parser.add_argument('customer_signature', type=int, choices=range(0,10),
  27                     metavar="customer_signature=[0-9]",
  28                     help="customer signature")
  29 parser.add_argument('board_version', type=int, choices=range(0,2**32),
  30                     metavar="board_version=[0-4294967295]",
  31                     help="board version")
  32 parser.add_argument('linux_loadaddr', nargs='?',
  33                     help="Kernel start address in 0xFFFFFFFF format")
  34 args = parser.parse_args()
  35
  36 if len(args.model) > MODEL_LEN:
  37     raise ValueError(f"Model '{args.model}' is greater than {MODEL_LEN} bytes")
  38
  39 if len(args.signature) > SIGNATURE_LEN:
  40     raise ValueError(f"Signature '{args.signature}' is greater than"
  41                      f"{SIGNATURE_LEN} bytes")
  42
  43 if args.signature == "os":
  44     if args.linux_loadaddr:
  45         if len(args.linux_loadaddr) > LINUXLOAD_LEN:
  46             raise ValueError(f"linux_loadaddr '{args.linux_loadaddr}' is greater"
  47                              f"than {LINUXLOAD_LEN} bytes")
  48         if (args.linux_loadaddr[0:2] != "0x"):
  49             raise ValueError(f"linux_loadaddr '{args.linux_loadaddr}' must use"
  50                              f"the 0x789ABCDE format")
  51         int(args.linux_loadaddr[2:],16)
  52     else:
  53         raise ValueError(f"linux_loadaddr is required for signature 'os'")
  54 else:
  55     args.linux_loadaddr = ""
  56
  57 checksum = 0
  58 size = 0
  59 while True:
  60     buf = args.source_file.read(BUFSIZE)
  61     if not buf:
  62         break
  63     checksum = sum(iter(buf),checksum) % (1<<32)
  64     size += len(buf)
  65
  66 args.dest_file.write(struct.pack('!I', checksum))
  67 args.dest_file.write(struct.pack(f'{MODEL_LEN}s',
  68                                  args.model.encode("ascii")))
  69 args.dest_file.write(struct.pack(f'{SIGNATURE_LEN}s',
  70                                  args.signature.encode("ascii")))
  71 args.dest_file.write(struct.pack('!B', args.partition))
  72 args.dest_file.write(struct.pack('!B', 0x40)) # ??? This header size?
  73 args.dest_file.write(struct.pack('!B', 0x00)) # ??? Encrypted?
  74 args.dest_file.write(struct.pack('!B', args.customer_signature))
  75 args.dest_file.write(struct.pack('!I', args.board_version))
  76 args.dest_file.write(struct.pack('!I', size))
  77 args.dest_file.write(struct.pack(f'{LINUXLOAD_LEN}s',
  78                                  args.linux_loadaddr.encode("ascii")))
  79 args.dest_file.write(struct.pack('!2x'))
  80
  81 args.source_file.seek(0)
  82 while True:
  83     buf = args.source_file.read(BUFSIZE)
  84     if not buf:
  85         break
  86     args.dest_file.write(buf)