firmware/hantek-dso/parsepe.py

   1 #!/usr/bin/python3
   2 ##
   3 ## This file is part of the sigrok-util project.
   4 ##
   5 ## Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
   6 ##
   7 ## This program is free software; you can redistribute it and/or modify
   8 ## it under the terms of the GNU General Public License as published by
   9 ## the Free Software Foundation; either version 3 of the License, or
  10 ## (at your option) any later version.
  11 ##
  12 ## This program is distributed in the hope that it will be useful,
  13 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 ## GNU General Public License for more details.
  16 ##
  17 ## You should have received a copy of the GNU General Public License
  18 ## along with this program; if not, see <http://www.gnu.org/licenses/>.
  19 ##
  20
  21 import sys
  22 import os
  23 from getopt import getopt
  24 import struct
  25
  26
  27 def parse(filename):
  28         f = open(filename, 'rb')
  29         if f.read(2) != b'MZ':
  30                 raise Exception("MZ signature not found.")
  31
  32         sections = []
  33         # long e_lfanew
  34         f.seek(0x3c)
  35         pe_ptr = struct.unpack("<L", f.read(4))[0]
  36         f.seek(pe_ptr)
  37         if f.read(4) != b'\x50\x45\x00\x00':
  38                 raise Exception("PE signature not found.")
  39         # skip Machine
  40         f.seek(f.tell() + 2)
  41         sections.append(['header', 324, 0])
  42         num_sections = struct.unpack("<H", f.read(2))[0]
  43         # skip TimeDateStamp
  44         f.seek(f.tell() + 4)
  45         symboltable_address = struct.unpack("<L", f.read(4))[0]
  46         num_symbols = struct.unpack("<L", f.read(4))[0]
  47         optheader_size = struct.unpack("<H", f.read(2))[0]
  48         # skip past PE header and PE optional header
  49         f.seek(f.tell() + 2 + optheader_size)
  50
  51         for i in range(num_sections):
  52                 name = f.read(8).decode('ascii', errors='ignore').strip('\x00')
  53                 # skip past Misc and VirtualAddress
  54                 f.seek(f.tell() + 8)
  55                 # SizeOfRawData
  56                 size = struct.unpack("<L", f.read(4))[0]
  57                 # PointerToRawData
  58                 ptr = struct.unpack("<L", f.read(4))[0]
  59                 # skip to next section header
  60                 f.seek(f.tell() + 16)
  61                 sections.append([name, size, ptr])
  62
  63         symbols = []
  64         addr = symboltable_address
  65         stringtable_address = symboltable_address + num_symbols * 18
  66         for i in range(num_symbols):
  67                 f.seek(addr)
  68                 tmp = f.read(8)
  69                 symaddr = struct.unpack("<L", f.read(4))[0]
  70                 # skip SectionNumber and Type
  71                 symtype = struct.unpack("B", f.read(1))[0]
  72                 f.seek(f.tell() + 4)
  73                 if tmp[:4] == b'\x00\x00\x00\x00':
  74                         # symbol name is in the string table
  75                         straddr = stringtable_address + struct.unpack("<l", tmp[4:])[0]
  76                         f.seek(straddr)
  77                         tmpname = f.read(64)
  78                         name = tmpname[:tmpname.find(b'\x00')]
  79                 else:
  80                         name = tmp
  81                 name = name.decode('ascii', errors='ignore').strip('\x00')
  82                 # need IMAGE_SYM_CLASS_EXTERNAL
  83                 if symtype == 0x02:
  84                         size = 0
  85                 else:
  86                         size = None
  87                 if i != 0 and symbols[-1][2] is not None and symaddr > symbols[-1][1]:
  88                         symbols[-1][2] = symaddr - symbols[-1][1]
  89                 symbols.append([name, symaddr, size])
  90                 addr += 18
  91
  92         f.close()
  93
  94         return sections, symbols
  95
  96
  97 def list_all(filename):
  98         sections, symbols = parse(filename)
  99         if sections:
 100                 print("Sections:\n    Name         Size\t  Position")
 101                 cnt = 0
 102                 for name, size, address in sections:
 103                         print("%-3d %-8s    %5d\t  0x%.8x" % (cnt, name, size, address))
 104                         cnt += 1
 105         if symbols:
 106                 print("\nSymbol table:\n   Address     Size    Symbol")
 107                 for symbol, address, size in symbols:
 108                         if size is not None:
 109                                 sizestr = "%5d" % size
 110                         else:
 111                                 sizestr = "     "
 112                         print("0x%.8x  %s    %-8s" % (address, sizestr, symbol))
 113                 print()
 114
 115
 116 def extract_symbol(filename, symbol):
 117         sections, symbols = parse(filename)
 118         if not symbols:
 119                 return None
 120         data = None
 121         for symbolname, address, size in symbols:
 122                 if symbolname == symbol:
 123                         if size is None:
 124                                 raise Exception("symbol %s found, but has unknown size")
 125                         f = open(filename, 'rb')
 126                         f.seek(address)
 127                         data = f.read(size)
 128                         f.close()
 129                         if len(data) != size:
 130                                 raise Exception("short file")
 131                         break
 132
 133         if data is None:
 134                 raise Exception("symbol %s not found" % symbol)
 135
 136         return data
 137
 138
 139
 140 def usage():
 141         print("usage: parsepe.py [-s <symbol>] <-l|-x> <filename>")
 142         print("  -l   list all sections and symbols in file")
 143         print("  -x   extract symbol from file (specify symbol name with -s)")
 144         sys.exit()
 145
 146
 147 #
 148 # main
 149 #
 150
 151 if __name__ == '__main__':
 152         filename = symbol = mode = None
 153         opts, args = getopt(sys.argv[1:], 's:lx')
 154         for opt, arg in opts:
 155                 if opt == '-s':
 156                         symbol = arg
 157                 elif opt == '-l':
 158                         mode = 'list'
 159                 elif opt == '-x':
 160                         mode = 'extract'
 161
 162         if len(args) != 1:
 163                 usage()
 164         if mode is None and symbol is None:
 165                 usage()
 166
 167         try:
 168                 filename = args[0]
 169                 if mode == 'list':
 170                         list_all(filename)
 171                 elif mode == 'extract':
 172                         if symbol is None:
 173                                 raise Exception("specify a symbol to extract")
 174                         data = extract_symbol(filename, symbol)
 175                         outfile = os.path.splitext(filename)[0] + symbol
 176                         open(outfile, 'wb').write(data)
 177                         print("saved %d bytes to %s" % (len(data), outfile))
 178                 else:
 179                         raise Exception("specify -l or -x")
 180         except Exception as e:
 181                 print("Error: %s" % str(e))
 182
 183