scripts/event_dump.py

   1 #!/usr/bin/env python3
   2 # SPDX-License-Identifier: GPL-2.0+
   3
   4 """Decode the evspy_info linker list in a U-Boot ELF image"""
   5
   6 from argparse import ArgumentParser
   7 import os
   8 import re
   9 import struct
  10 import sys
  11
  12 our_path = os.path.dirname(os.path.realpath(__file__))
  13 src_path = os.path.dirname(our_path)
  14
  15 sys.path.insert(1, os.path.join(our_path, '../tools'))
  16
  17 from binman import elf
  18 from u_boot_pylib import tools
  19
  20 # A typical symbol looks like this:
  21 #   _u_boot_list_2_evspy_info_2_EVT_MISC_INIT_F_3_sandbox_misc_init_f
  22 PREFIX_FULL = '_u_boot_list_2_evspy_info_2_'
  23 PREFIX_SIMPLE = '_u_boot_list_2_evspy_info_simple_2_'
  24 RE_EVTYPE_FULL = re.compile('%s(.*)_3_.*' % PREFIX_FULL)
  25 RE_EVTYPE_SIMPLE = re.compile('%s(.*)_3_.*' % PREFIX_SIMPLE)
  26
  27 def show_sym(fname, data, endian, evtype, sym):
  28     """Show information about an evspy entry
  29
  30     Args:
  31         fname (str): Filename of ELF file
  32         data (bytes): Data for this symbol
  33         endian (str): Endianness to use ('little', 'big', 'auto')
  34         evtype (str): Event type, e.g. 'MISC_INIT_F'
  35         sym (elf.Symbol): Symbol to show
  36     """
  37     def _unpack_val(sym_data, offset):
  38         start = offset * func_size
  39         val_data = sym_data[start:start + func_size]
  40         fmt = '%s%s' % ('>' if endian == 'big' else '<',
  41                         'L' if func_size == 4 else 'Q')
  42         val = struct.unpack(fmt, val_data)[0]
  43         return val
  44
  45     # Get the data, which is a struct evspy_info
  46     sym_data = data[sym.offset:sym.offset + sym.size]
  47
  48     # Figure out the word size of the struct
  49     func_size = 4 if sym.size < 16 else 8
  50
  51     # Read the function name for evspy_info->func
  52     while True:
  53         # Switch to big-endian if we see a failure
  54         func_addr = _unpack_val(sym_data, 0)
  55         func_name = elf.GetSymbolFromAddress(fname, func_addr)
  56         if not func_name and endian == 'auto':
  57             endian = 'big'
  58         else:
  59             break
  60     has_id = sym.size in [12, 24]
  61     if has_id:
  62         # Find the address of evspy_info->id in the ELF
  63         id_addr = _unpack_val(sym_data, 2)
  64
  65         # Get the file offset for that address
  66         id_ofs = elf.GetFileOffset(fname, id_addr)
  67
  68         # Read out a nul-terminated string
  69         id_data = data[id_ofs:id_ofs + 80]
  70         pos = id_data.find(0)
  71         if pos:
  72             id_data = id_data[:pos]
  73         id_str = id_data.decode('utf-8')
  74     else:
  75         id_str = None
  76
  77     # Find the file/line for the function
  78     cmd = ['addr2line', '-e', fname, '%x' % func_addr]
  79     out = tools.run(*cmd).strip()
  80
  81     # Drop the full path if it is the current directory
  82     if out.startswith(src_path):
  83         out = out[len(src_path) + 1:]
  84     print('%-20s  %-30s  %s' % (evtype, id_str or f'f:{func_name}', out))
  85
  86 def show_event_spy_list(fname, endian):
  87     """Show a the event-spy- list from a U-Boot image
  88
  89     Args:
  90         fname (str): Filename of ELF file
  91         endian (str): Endianness to use ('little', 'big', 'auto')
  92     """
  93     syms = elf.GetSymbolFileOffset(fname, [PREFIX_FULL, PREFIX_SIMPLE])
  94     data = tools.read_file(fname)
  95     print('%-20s  %-30s  %s' % ('Event type', 'Id', 'Source location'))
  96     print('%-20s  %-30s  %s' % ('-' * 20, '-' * 30, '-' * 30))
  97     for name, sym in syms.items():
  98         m_evtype = RE_EVTYPE_FULL.search(name)
  99         if not m_evtype:
 100             m_evtype = RE_EVTYPE_SIMPLE.search(name)
 101         evtype = m_evtype .group(1)
 102         show_sym(fname, data, endian, evtype, sym)
 103
 104 def main(argv):
 105     """Main program
 106
 107     Args:
 108         argv (list of str): List of program arguments, excluding arvg[0]
 109     """
 110     epilog = 'Show a list of even spies in a U-Boot EFL file'
 111     parser = ArgumentParser(epilog=epilog)
 112     parser.add_argument('elf', type=str, help='ELF file to decode')
 113     parser.add_argument('-e', '--endian', type=str, default='auto',
 114                         help='Big-endian image')
 115     args = parser.parse_args(argv)
 116     show_event_spy_list(args.elf, args.endian)
 117
 118 if __name__ == "__main__":
 119     main(sys.argv[1:])