Mercurial > lcfOS

comparison python/elffile.py @ 118:db8aafe00d27

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Added elf file read scripts
author Windel Bouwman
date Sat, 12 Jan 2013 09:39:23 +0100
parents
children bbf4c9b138d4
comparison
equal deleted inserted replaced
117:f2b37d78082d 118:db8aafe00d27
1 import struct
2
3 classes = {1:'ELF32', 2:'ELF64'}
4
5 class ElfFile:
6 def __init__(self, f):
7 self.f = f
8 self.parse()
9 def parse(self):
10 self.parseHeader()
11 self.parseSections()
12 self.parsePrograms()
13 @property
14 def ElfClass(self):
15 return classes[self.ei_class]
16 def parseHeader(self):
17 # Parse identifier
18 e_ident = self.f.read(16)
19 ELFMAGIC = bytes([0x7f]) + b'ELF'
20 assert e_ident[0:4] == ELFMAGIC
21 self.ei_class = e_ident[4]
22 print('ELF class: ', self.ElfClass)
23 assert self.ei_class in classes.keys()
24 self.ei_data = e_ident[5]
25 print('ei_data:', self.ei_data)
26 ei_version = e_ident[6]
27 assert ei_version == 1
28
29 # rest of the ELF header:
30 e_type = self.readHalf()
31 e_machine = self.readHalf()
32 e_version = self.readWord()
33 e_entry = self.readAddr()
34 e_phoff = self.readOff()
35 e_shoff = self.readOff()
36 e_flags = self.readWord()
37 e_ehsize = self.readHalf()
38 e_phentsize = self.readHalf()
39 e_phnum = self.readHalf()
40 e_shentsize = self.readHalf()
41 e_shnum = self.readHalf()
42 e_shstrndx = self.readHalf()
43
44 if self.ei_class == 1:
45 assert e_ehsize == 52
46 elif self.ei_class == 2:
47 assert e_ehsize == 64
48 print('program header size', e_phentsize, e_phnum)
49 print('section header size', e_shentsize, e_shnum, e_shstrndx)
50 def readFmt(self, fmt):
51 size = struct.calcsize(fmt)
52 return struct.unpack(fmt, self.f.read(size))
53 def readHalf(self):
54 return self.readFmt('<H')[0]
55 def readWord(self):
56 return self.readFmt('<I')[0]
57 def readAddr(self):
58 if self.ei_class == 1:
59 fmt = '<I'
60 elif self.ei_class == 2:
61 fmt = '<Q'
62 else:
63 raise Exception()
64 return self.readFmt(fmt)[0]
65 readOff = readAddr
66
67 def printProgramHeaders(self):
68 pass