openwrt 芯片扩容修改固件步骤

youxiaojie

Nov 2022

../../../staging_dir/host/bin/lzma d tplink_tl-wdr4310-v1-kernel.bin 4310.unlzma
2.
using hexedit software okteta edit 4310.unlzma three offsets need modified (after A4):
0072:5258 replace hex 00020000 007d0000 with 00200000 00fd0000
0073:5272 replace string 7f with ff
0073:5298 replace hex 007f0000 00010000 with 00ff0000 00010000
3.
../../../staging_dir/host/bin/lzma e -lc1 -lp2 4310.unlzma tplink_tl-wdr4310-v1-kernel.bin
4.

modify openwrt-imagebuilder-22.03.2-ath79-generic.Linux-x86_64/target/linux/ath79/image/generic-tp-link.mk
define Device/tplink_tl-wdr4310-v1
  $(Device/tplink-8mlzma) ---> changing to 16mlzma
  SOC := ar9344
  DEVICE_MODEL := TL-WDR4310
  DEVICE_VARIANT := v1
  DEVICE_PACKAGES := kmod-usb2 kmod-usb-ledtrig-usbport
  TPLINK_HWID := 0x43100001
  SUPPORTED_DEVICES += tl-wdr4300
endef
TARGET_DEVICES += tplink_tl-wdr4310-v1

make image PROFILE=tplink_tl-wdr4310-v1 PACKAGES="uhttpd luci luci-ssl"

youxiaojie

youxiaojie

Nov 2022

#!/usr/bin/env python
# -*- coding: utf-8 -*-

__author__ = "Taras Gavrylenko"
__copyright__ = "Copyright 2020, The OpenWrt Project"
__version__ = "0.9"
__email__ = "gavrylenko.taras@gmail.com"
__status__ = "Beta"

"""
OpenWrt TP-Link kernel DTS patcher allows to use release 19.07 kernel
and packages on hardware modded devices with increased flash chip size.

Set environment variable $LZMA_UTIL_PATH with path to LZMA utility
Recommended LZMA 4.65 : Igor Pavlov : Public domain : 2009-02-03
from Openwrt originals

Be sure you have Python interpreter 3.8 or higher
Run: python3.8 kernel_patcher.py <path_to_kernel_file>

Script stages:
1. Rename original kernel to *.bak
2. Unpack original kernel
3. Patch DTS partition table
4. Pack new kernel
"""

import argparse
import logging
import os
import subprocess

from pathlib import Path

logging.basicConfig(
    format='%(asctime)s %(levelname)s %(message)s',
    level=logging.INFO)
logger = logging.getLogger(__name__)


def run_command(cmd: str):
    return subprocess.call(cmd, shell=True)


def compress_lzma(lzma_util: str, raw_path: Path, lzma_path: Path) -> int:
    cmd = f'{lzma_util} e {raw_path} {lzma_path} -lc1 -lp2'
    status = run_command(cmd)
    if status != 0:
        raise RuntimeError(f'Failed to compress {raw_path}')
    return lzma_path.stat().st_size


def decompress_lzma(lzma_util: str, lzma_path: Path, raw_path: Path) -> int:
    cmd = f'{lzma_util} d {lzma_path} {raw_path}'
    status = run_command(cmd)
    if status != 0:
        raise RuntimeError(f'Failed to decompress {lzma_path}')
    return raw_path.stat().st_size


def resize_kernel_dts(krnl_path: Path):
    chunk_num = 0
    chunk_size = 64 * 1024
    with krnl_path.open(mode='rb+') as f_out:
        while data := f_out.read(chunk_size):
            if (offset := data.find(b'partition@20000')) > 0:
                ofs_part = chunk_num * chunk_size + offset
                logger.info('Found DTS partition table at: '
                            f'0x{ofs_part:08x}')
                break
            chunk_num += 1
        else:
            raise RuntimeError('Could not find DTS partition table')
        f_out.seek(ofs_part)
        data = bytearray(f_out.read(0x100))
        if (offset := data.find(b'\xaa\0\x02\0\0\0\x7d\0\0')) > 0:
            data[offset+6] |= 0xff
        else:
            raise RuntimeError('Partition pattern not found')
        if (offset := data.find(b'partition@7f0000')) > 0:
            data[offset+10] = ord('f')
        else:
            raise RuntimeError('Partition pattern not found')
        if (offset := data.find(b'\xaa\0\x7f\0\0\0\x01\0\0')) > 0:
            data[offset+2] |= 0xff
        else:
            raise RuntimeError('Partition pattern not found')
        f_out.seek(ofs_part)
        f_out.write(data)


def main():
    logger.info('OpenWrt Imagebuilder DTS patcher v0.9')

    lzma_util_path = os.getenv('LZMA_UTIL_PATH')
    if lzma_util_path is None:
        logger.error('Compressor utility path is not set: LZMA_UTIL_PATH')
        exit(1)

    parser = argparse.ArgumentParser()
    parser.add_argument('image', help='OpenWrt kernel image file')
    args = parser.parse_args()

    krnl_path = Path(args.image)
    if krnl_path.is_file() is False:
        logger.error(f'Kernel image file does not exist: {krnl_path}')
        exit(1)
    krnl_size = krnl_path.stat().st_size
    logger.info(f'Processing kernel image file: {krnl_path}')
    logger.info(f'Origin kernel size: 0x{krnl_size:08x}')
    kernel_raw_path = Path(krnl_path.with_suffix('.raw'))
    logger.info('Decompressing kernel...')
    krnl_raw_size = decompress_lzma(
        lzma_util_path, krnl_path, kernel_raw_path)
    logger.info(f'Decompressed kernel size: 0x{krnl_raw_size:08x}')
    logger.info('Resizing kernel DTS...')
    resize_kernel_dts(kernel_raw_path)
    krnl_path.rename(krnl_path.with_suffix('.bak'))
    logger.info('Compressing kernel...')
    krnl_lzma_size = compress_lzma(
        lzma_util_path, kernel_raw_path, krnl_path)
    logger.info(f'Compressed kernel size: 0x{krnl_lzma_size:08x}')
    if krnl_lzma_size > krnl_size:
        logger.warning('Re-compressed kernel is bigger than original.')
    logger.info('Done')


if __name__ == '__main__':
    main()