122 lines
2.9 KiB
Python
Executable File
122 lines
2.9 KiB
Python
Executable File
#!/usr/bin/env python3
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"""
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# SPDX-License-Identifier: GPL-2.0-or-later
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#
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# sercomm-kernel-header.py: Creates Sercomm kernel header
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#
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# Copyright © 2022 Mikhail Zhilkin
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"""
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import argparse
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import binascii
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import os
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import struct
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KERNEL_HEADER_SIZE = 0x100
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PADDING = 0xff
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ROOTFS_FAKE_HEADER = "UBI#"
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def auto_int(x):
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return int(x, 0)
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def create_kernel_header(args):
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out_file = open(args.header_file, "wb")
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header = get_kernel_header(args)
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out_file.write(header)
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out_file.close()
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def get_kernel_header(args):
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header = bytearray([PADDING] * KERNEL_HEADER_SIZE)
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struct.pack_into('<L', header, 0xc, 0xffffff02)
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struct.pack_into('<L', header, 0x1c, 0x0)
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struct.pack_into('<L', header, 0x34, 0x0)
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struct.pack_into('<L', header, 0x10, args.kernel_offset)
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struct.pack_into('<L', header, 0x28, args.rootfs_offset)
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if (args.rootfs_file):
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if (args.rootfs_checking_size):
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rootfs_size = args.rootfs_checking_size
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else:
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rootfs_size = os.path.getsize(args.rootfs_file)
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buf = open(args.rootfs_file,'rb').read(rootfs_size)
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crc = binascii.crc32(buf) & 0xffffffff
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else:
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rootfs_size = len(ROOTFS_FAKE_HEADER)
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crc = binascii.crc32(str.encode(ROOTFS_FAKE_HEADER)) & \
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0xffffffff
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struct.pack_into('<L', header, 0x2c, rootfs_size)
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struct.pack_into('<L', header, 0x30, crc)
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kernel_size = os.path.getsize(args.kernel_file)
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struct.pack_into('<L', header, 0x14, kernel_size)
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kernel_end_offset = args.kernel_offset + kernel_size
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struct.pack_into('<L', header, 0x4, kernel_end_offset)
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buf = open(args.kernel_file,'rb').read()
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crc = binascii.crc32(buf) & 0xffffffff
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struct.pack_into('<L', header, 0x18, crc)
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crc = binascii.crc32(header) & 0xffffffff
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struct.pack_into('<L', header, 0x8, crc)
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struct.pack_into('<L', header, 0x0, 0x726553)
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return header
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def main():
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global args
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parser = argparse.ArgumentParser(description='This script generates \
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a kernel header for the Sercomm mt7621 devices')
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parser.add_argument('--kernel-image',
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dest='kernel_file',
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action='store',
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type=str,
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help='Path to a Kernel binary image')
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parser.add_argument('--kernel-offset',
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dest='kernel_offset',
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action='store',
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type=auto_int,
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help='Kernel offset')
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parser.add_argument('--rootfs-offset',
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dest='rootfs_offset',
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action='store',
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type=auto_int,
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help='RootFS offset')
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parser.add_argument('--output-header',
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dest='header_file',
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action='store',
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type=str,
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help='Output kernel header file')
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parser.add_argument('--rootfs-image',
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dest='rootfs_file',
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action='store',
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type=str,
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help='Path to RootFS binary image (optional)')
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parser.add_argument('--rootfs-checking-size',
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dest='rootfs_checking_size',
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action='store',
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type=auto_int,
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help='Bytes count for CRC calculation (optional)')
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args = parser.parse_args()
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if ((not args.kernel_file) or
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(not args.kernel_offset) or
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(not args.rootfs_offset) or
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(not args.header_file)):
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parser.print_help()
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exit()
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create_kernel_header(args)
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main()
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