scripts: add cameo image header generator

The cameo header is a 0x40-byte header used by D-Link DGS 1210 switches
and Apresia ApresiaLightGS series. cameo-imghdr.py is a clean-room
reimplementation of imghdr present in the DGS-1210-28-GPL package.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
[fix board_version argument's help text]
Signed-off-by: Sander Vanheule <sander@svanheule.net>
This commit is contained in:
Luiz Angelo Daros de Luca 2022-06-24 16:05:16 -03:00 committed by Sander Vanheule
parent 6556cad99d
commit 2fd66e058b

86
scripts/cameo-imghdr.py Executable file
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#!/usr/bin/python3
# SPDX-License-Identifier: GPL-2.0-or-later
#
# Copyright (C) 2022 Luiz Angelo Daros de Luca <luizluca@gmail.com>
#
# Cameo Image header geneator, used by some D-Link DGS-1210 switches
# and APRESIA ApresiaLightGS series
#
import argparse
import pathlib
import socket
import struct
MODEL_LEN = 20
SIGNATURE_LEN = 16
LINUXLOAD_LEN = 10
BUFSIZE = 4096
parser = argparse.ArgumentParser(description='Generate Cameo firmware header.')
parser.add_argument('source_file', type=argparse.FileType('rb'))
parser.add_argument('dest_file', type=argparse.FileType('wb'))
parser.add_argument('model')
parser.add_argument('signature')
parser.add_argument('partition', type=int, choices=range(0,10),
metavar="partition=[0-9]",help="partition id")
parser.add_argument('customer_signature', type=int, choices=range(0,10),
metavar="customer_signature=[0-9]",
help="customer signature")
parser.add_argument('board_version', type=int, choices=range(0,2**32),
metavar="board_version=[0-4294967295]",
help="board version")
parser.add_argument('linux_loadaddr', nargs='?',
help="Kernel start address in 0xFFFFFFFF format")
args = parser.parse_args()
if len(args.model) > MODEL_LEN:
raise ValueError(f"Model '{args.model}' is greater than {MODEL_LEN} bytes")
if len(args.signature) > SIGNATURE_LEN:
raise ValueError(f"Signature '{args.signature}' is greater than"
f"{SIGNATURE_LEN} bytes")
if args.signature == "os":
if args.linux_loadaddr:
if len(args.linux_loadaddr) > LINUXLOAD_LEN:
raise ValueError(f"linux_loadaddr '{args.linux_loadaddr}' is greater"
f"than {LINUXLOAD_LEN} bytes")
if (args.linux_loadaddr[0:2] != "0x"):
raise ValueError(f"linux_loadaddr '{args.linux_loadaddr}' must use"
f"the 0x789ABCDE format")
int(args.linux_loadaddr[2:],16)
else:
raise ValueError(f"linux_loadaddr is required for signature 'os'")
else:
args.linux_loadaddr = ""
checksum = 0
size = 0
while True:
buf = args.source_file.read(BUFSIZE)
if not buf:
break
checksum = sum(iter(buf),checksum) % (1<<32)
size += len(buf)
args.dest_file.write(struct.pack('!I', checksum))
args.dest_file.write(struct.pack(f'{MODEL_LEN}s',
args.model.encode("ascii")))
args.dest_file.write(struct.pack(f'{SIGNATURE_LEN}s',
args.signature.encode("ascii")))
args.dest_file.write(struct.pack('!B', args.partition))
args.dest_file.write(struct.pack('!B', 0x40)) # ??? This header size?
args.dest_file.write(struct.pack('!B', 0x00)) # ??? Encrypted?
args.dest_file.write(struct.pack('!B', args.customer_signature))
args.dest_file.write(struct.pack('!I', args.board_version))
args.dest_file.write(struct.pack('!I', size))
args.dest_file.write(struct.pack(f'{LINUXLOAD_LEN}s',
args.linux_loadaddr.encode("ascii")))
args.dest_file.write(struct.pack('!2x'))
args.source_file.seek(0)
while True:
buf = args.source_file.read(BUFSIZE)
if not buf:
break
args.dest_file.write(buf)