xref: /openbmc/linux/scripts/gdb/linux/config.py (revision 4fc4dca8) 
1# SPDX-License-Identifier: GPL-2.0
2#
3# Copyright 2019 Google LLC.
4
5import gdb
6import zlib
7
8from linux import utils
9
10
11class LxConfigDump(gdb.Command):
12    """Output kernel config to the filename specified as the command
13       argument. Equivalent to 'zcat /proc/config.gz > config.txt' on
14       a running target"""
15
16    def __init__(self):
17        super(LxConfigDump, self).__init__("lx-configdump", gdb.COMMAND_DATA,
18                                           gdb.COMPLETE_FILENAME)
19
20    def invoke(self, arg, from_tty):
21        if len(arg) == 0:
22            filename = "config.txt"
23        else:
24            filename = arg
25
26        try:
27            py_config_ptr = gdb.parse_and_eval("kernel_config_data + 8")
28            py_config_size = gdb.parse_and_eval(
29                    "sizeof(kernel_config_data) - 1 - 8 * 2")
30        except gdb.error as e:
31            raise gdb.GdbError("Can't find config, enable CONFIG_IKCONFIG?")
32
33        inf = gdb.inferiors()[0]
34        zconfig_buf = utils.read_memoryview(inf, py_config_ptr,
35                                            py_config_size).tobytes()
36
37        config_buf = zlib.decompress(zconfig_buf, 16)
38        with open(filename, 'wb') as f:
39            f.write(config_buf)
40
41        gdb.write("Dumped config to " + filename + "\n")
42
43
44LxConfigDump()
45