]> git.alrj.org Git - bold.git/commitdiff
First working version.
authorAmand Tihon <amand.tihon@alrj.org>
Thu, 21 May 2009 13:31:18 +0000 (15:31 +0200)
committerAmand Tihon <amand.tihon@alrj.org>
Thu, 21 May 2009 13:31:18 +0000 (15:31 +0200)
bold.py [new file with mode: 0755]
elf/BinArray.py [new file with mode: 0644]
elf/__init__.py [new file with mode: 0644]
elf/constants.py [new file with mode: 0644]
elf/elf.py [new file with mode: 0644]

diff --git a/bold.py b/bold.py
new file mode 100755 (executable)
index 0000000..74a8ba2
--- /dev/null
+++ b/bold.py
@@ -0,0 +1,199 @@
+#! /usr/bin/python
+# -*- coding: utf-8 -*-
+# kate: space-indent on; indent-width 2; mixedindent off; indent-mode python;
+
+# Copyright (C) 2009 Amand 'alrj' Tihon <amand.tihon@alrj.org>
+#
+# This file is part of bold, the Byte Optimized Linker.
+# Heavily inspired by elf.h from the GNU C Library.
+#
+# You can redistribute this file and/or modify it under the terms of the
+# GNU Lesser General Public License as published by the Free Software
+# Foundation, version 2.1.
+
+from elf.BinArray import BinArray
+from elf.constants import *
+from elf.elf import Elf64, Elf64_Phdr, TextSegment, DataSegment, Dynamic, Interpreter
+import struct, sys
+
+infiles = [Elf64(n) for n in sys.argv[1:]]
+for i in infiles:
+  i.resolve_names()
+  i.find_symbols()
+
+#h = infile.header
+#print "Class:                             %s" % h.e_ident.ei_class
+#print "Data:                              %s" % h.e_ident.ei_data
+#print "Version:                           %s" % h.e_ident.ei_version
+#print "OS/ABI:                            %s" % h.e_ident.ei_osabi
+#print "ABI Version:                       %s" % h.e_ident.ei_abiversion
+#print "Type:                              %s" % h.e_type
+#print "Machine:                           %s" % h.e_machine
+#print "Version:                           %s" % h.e_version
+#print "Entry point address:               0x%x" % h.e_entry
+#print "Start of program headers:          %i (bytes into file)" % h.e_phoff
+#print "Start of section headers:          %i (bytes into file)" % h.e_shoff
+#print "Flags:                             0x%x" % h.e_flags
+#print "Size of this header:               %i (bytes)" % h.e_ehsize
+#print "Size of program headers:           %i (bytes)" % h.e_phentsize
+#print "Number of program headers:         %i" % h.e_phnum
+#print "Size of section headers:           %i (bytes)" % h.e_shentsize
+#print "Number of section headers:         %i" % h.e_shnum
+
+#print "Section header string table index: %s" % h.e_shstrndx
+
+#print
+
+#print "Section Headers:"
+#for sh in infile.shdrs:
+  #print "[%2i] %-16s  %-16s %016x  %08x" % (sh.index, sh.name, sh.sh_type,
+    #sh.sh_addr, sh.sh_offset)
+  #print "     %016x  %016x  %-5s %4i  %4i  %4i" % (sh.sh_size, sh.sh_entsize,
+    #sh.sh_flags, sh.sh_link, sh.sh_info, sh.sh_addralign)
+#print
+
+#for sh in infile.shdrs :
+  #if sh.sh_type == SHT_STRTAB:
+    ##print "Section %i is a string table with entries :" % sh.index
+    ##for i, name in sh.content.iteritems():
+    ##  print "%4i %s" % (i, name)
+    #print
+  #elif sh.sh_type == SHT_SYMTAB:
+    #print "Section %i is a symbol table with entries :" % sh.index
+    #print "   Num:    Value          Size Type    Bind   Vis      Ndx Name"
+    #for i, sym in enumerate(sh.content.symtab):
+      #print "%6i: %016x %5s %-7s %-6s %-7s %4s %s" % (i,
+        #sym.st_value, sym.st_size, sym.st_type, sym.st_binding,
+        #sym.st_visibility, sym.st_shndx, sym.name)
+    #print
+  #elif sh.sh_type == SHT_RELA:
+    #print "Section %s is a RELA that applies to %s:" % (sh.name, sh.target.name)
+    #print "  Offset          Info           Type           Sym. Value    Sym. Name + Addend"
+    #for i in sh.content.relatab:
+      #print "%012x  %012x %-16s  %016x %s%s + %x" % (i.r_offset, i.r_info,
+      #i.r_type, i.symbol.st_value, i.symbol.name,
+      #sh.owner.shdrs[i.symbol.st_shndx].name,
+      #i.r_addend)
+    #print
+
+
+
+outfile = Elf64()
+
+text_segment = TextSegment()
+data_segment = DataSegment(align=0x100000)
+
+outfile.add_segment(text_segment)
+outfile.add_segment(data_segment)
+
+
+outfile.header.e_ident.make_default_amd64()
+outfile.header.e_phoff = outfile.header.size
+outfile.header.e_type = ET_EXEC
+text_segment.add_content(outfile.header)
+
+ph_text = Elf64_Phdr()
+ph_text.p_type = PT_LOAD
+ph_text.p_align = 0x100000
+outfile.add_phdr(ph_text)
+text_segment.add_content(ph_text)
+
+ph_data = Elf64_Phdr()
+ph_data.p_type = PT_LOAD
+ph_data.p_align = 0x100000
+outfile.add_phdr(ph_data)
+text_segment.add_content(ph_data)
+
+ph_dynamic = Elf64_Phdr()
+ph_dynamic.p_type = PT_DYNAMIC
+outfile.add_phdr(ph_dynamic)
+text_segment.add_content(ph_dynamic)
+
+ph_interp = Elf64_Phdr()
+ph_interp.p_type = PT_INTERP
+outfile.add_phdr(ph_interp)
+text_segment.add_content(ph_interp)
+
+interp = Interpreter()
+text_segment.add_content(interp)
+
+dynamic = Dynamic()
+dynamic.add_shlib("libGL.so.1")
+dynamic.add_shlib("libSDL-1.2.so.0")
+dynamic.add_symtab(0)
+dynamic.add_debug()
+data_segment.add_content(dynamic)
+text_segment.add_content(dynamic.strtab)
+
+
+# Find interresting sections in input file
+for i in infiles:
+  for sh in i.shdrs:
+    if (sh.sh_flags & SHF_ALLOC):
+      if (sh.sh_flags & SHF_EXECINSTR):
+        text_segment.add_content(sh.content)
+      else: # No exec, it's for .data
+        if (sh.sh_type == SHT_NOBITS):
+          data_segment.add_nobits(sh.content)
+        else:
+          data_segment.add_content(sh.content)
+
+
+outfile.layout(base_vaddr=0x400000)
+
+
+# Set addresses, sizes, etc. where known
+outfile.header.e_phnum = len(outfile.phdrs)
+outfile.header.e_phoff = outfile.phdrs[0].file_offset
+
+ph_text.p_offset = text_segment.file_offset
+ph_text.p_vaddr = text_segment.virt_addr
+ph_text.p_filesz = text_segment.physical_size
+ph_text.p_memsz = text_segment.logical_size
+
+ph_data.p_offset = data_segment.file_offset
+ph_data.p_vaddr = data_segment.virt_addr
+ph_data.p_filesz = data_segment.physical_size
+ph_data.p_memsz = data_segment.logical_size
+
+ph_interp.p_offset = interp.file_offset
+ph_interp.p_vaddr = interp.virt_addr
+ph_interp.p_filesz = interp.physical_size
+ph_interp.p_memsz = interp.logical_size
+
+ph_dynamic.p_offset = dynamic.file_offset
+ph_dynamic.p_vaddr = dynamic.virt_addr
+ph_dynamic.p_filesz = dynamic.physical_size
+ph_dynamic.p_memsz = dynamic.logical_size
+
+for i in infiles:
+  outfile.undefined_symbols.extend(i.undefined_symbols)
+
+dt_dbg = dynamic.dt_debug_address
+outfile.global_symbols["_dt_debug"] = dt_dbg
+outfile.global_symbols["_DYNAMIC"] = dynamic.virt_addr
+
+# Take all globally declared symbols, and put them in outfile's dict
+for i in infiles:
+  for s in i.global_symbols:
+    section_addr = i.global_symbols[s][0].content.virt_addr
+    addr = section_addr + i.global_symbols[s][1]
+    if s in outfile.global_symbols:
+      print "Symbol '%s' defined more than once."
+      exit(1)
+    outfile.global_symbols[s] = addr
+
+for i in infiles:
+  i.apply_relocation(outfile.global_symbols)
+
+_start = outfile.global_symbols["_start"]
+outfile.header.e_entry = _start
+
+# outfile.apply_global_relocation()
+
+f = open("prout", "wb")
+outfile.toBinArray().tofile(f)
+f.close()
+
+
+
diff --git a/elf/BinArray.py b/elf/BinArray.py
new file mode 100644 (file)
index 0000000..ea88cad
--- /dev/null
@@ -0,0 +1,23 @@
+# -*- coding: utf-8 -*-
+
+# kate: space-indent on; indent-width 2; mixedindent off; indent-mode python;
+
+# Copyright (C) 2009 Amand 'alrj' Tihon <amand.tihon@alrj.org>
+#
+# This file is part of bold, the Byte Optimized Linker.
+# Heavily inspired by elf.h from the GNU C Library.
+#
+# You can redistribute this file and/or modify it under the terms of the
+# GNU Lesser General Public License as published by the Free Software
+# Foundation, version 2.1.
+
+from array import array
+import struct
+
+class BinArray(array):
+  """A specialized array that contains bytes"""
+  def __new__(cls, data=None):
+    if data:
+      return array.__new__(BinArray, "B", data)
+    else:
+      return array.__new__(BinArray, "B")
diff --git a/elf/__init__.py b/elf/__init__.py
new file mode 100644 (file)
index 0000000..c25fb45
--- /dev/null
@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+
+# kate: space-indent on; indent-width 2; mixedindent off; indent-mode python;
+
+# Copyright (C) 2009 Amand 'alrj' Tihon <amand.tihon@alrj.org>
+#
+# This file is part of bold, the Byte Optimized Linker.
+# Heavily inspired by elf.h from the GNU C Library.
+#
+# You can redistribute this file and/or modify it under the terms of the
+# GNU Lesser General Public License as published by the Free Software
+# Foundation, version 2.1.
+
diff --git a/elf/constants.py b/elf/constants.py
new file mode 100644 (file)
index 0000000..72d0100
--- /dev/null
@@ -0,0 +1,241 @@
+# -*- coding: utf-8 -*-
+
+# kate: space-indent on; indent-width 2; mixedindent off; indent-mode python;
+
+# Copyright (C) 2009 Amand 'alrj' Tihon <amand.tihon@alrj.org>
+#
+# This file is part of bold, the Byte Optimized Linker.
+# Heavily inspired by elf.h from the GNU C Library.
+#
+# You can redistribute this file and/or modify it under the terms of the
+# GNU Lesser General Public License as published by the Free Software
+# Foundation, version 2.1.
+
+"""This file defines standard ELF constants."""
+
+class SymbolicConstant(long):
+  """Allows you to map a symbolic name with a given integer."""
+  _symbolics = {}
+  _default = None
+  def __new__(cls, value, symbolic=None):
+    if symbolic:
+      cls._symbolics[value] = symbolic
+    return long.__new__(cls, value)
+
+  def __str__(self):
+    if long(self) in self._symbolics:
+      return self._symbolics[long(self)]
+    elif self._default:
+      return self._default % long(self)
+    else:
+      return str(long(self))
+
+
+class ElfClass(SymbolicConstant):
+  _symbolics = {}
+ELFCLASSNONE = ElfClass(0, "Invalid ELF class")
+ELFCLASS32 = ElfClass(1, "ELF32")
+ELFCLASS64 = ElfClass(2, "ELF64")
+
+
+class ElfData(SymbolicConstant):
+  _symbolics = {}
+ELFDATANONE = ElfData(0, "Invalid data encoding")
+ELFDATA2LSB = ElfData(1, "Little endian")
+ELFDATA2MSB = ElfData(2, "Big endian")
+
+
+class ElfVersion(SymbolicConstant):
+  _symbolics = {}
+EV_NONE = ElfVersion(0, "Invalid ELF version")
+EV_CURRENT = ElfVersion(1, "Current version (1)")
+
+
+class ElfOsAbi(SymbolicConstant):
+  _symbolics = {}
+# Fill me
+ELFOSABI_NONE = ElfOsAbi(0, "UNIX - System V")
+ELFOSABI_SYSV = ElfOsAbi(0, "UNIX - System V")
+
+
+class ElfType(SymbolicConstant):
+  _symbolics = {}
+ET_NONE = ElfType(0, "No file type")
+ET_REL = ElfType(1, "Relocatable file")
+ET_EXEC = ElfType(2, "Executable file")
+ET_DYN = ElfType(3, "Shared object file")
+ET_CORE = ElfType(4, "Core file")
+
+
+class ElfMachine(SymbolicConstant):
+  _symbolics = {}
+# Fill me
+EM_NONE = ElfMachine(0, "No machine")
+EM_386 = ElfMachine(3, "Intel 80386")
+EM_X86_64 = ElfMachine(62, "AMD x86-64 architecture")
+
+class ElfSectionIndex(SymbolicConstant):
+  _symbolics = {}
+SHN_UNDEF = ElfSectionIndex(0, "UND")
+SHN_ABS = ElfSectionIndex(0xfff1, "ABS")
+SHN_COMMON = ElfSectionIndex(0xfff2, "COM")
+
+class ElfShType(SymbolicConstant):
+  _symbolics = {}
+SHT_NULL = ElfShType(0, "NULL")
+SHT_PROGBITS = ElfShType(1, "PROGBITS")
+SHT_SYMTAB = ElfShType(2, "SYMTAB")
+SHT_STRTAB = ElfShType(3, "STRTAB")
+SHT_RELA = ElfShType(4, "RELA")
+SHT_HASH = ElfShType(5, "HASH")
+SHT_DYNAMIC = ElfShType(6, "DYNAMIC")
+SHT_NOTE = ElfShType(7, "NOTE")
+SHT_NOBITS = ElfShType(8, "NOBITS")
+SHT_REL = ElfShType(9, "REL")
+SHT_SHLIB = ElfShType(10, "SHLIB")
+SHT_DYNSYM = ElfShType(11, "DYNSYM")
+
+SHF_WRITE = 0x1
+SHF_ALLOC =             1 << 1
+SHF_EXECINSTR =         1 << 2
+SHF_MERGE =             1 << 4
+SHF_STRINGS =           1 << 5
+SHF_INFO_LINK =         1 << 6
+SHF_LINK_ORDER =        1 << 7
+SHF_OS_NONCONFORMING =  1 << 8
+SHF_GROUP =             1 << 9
+SHF_TLS =               1 << 10
+SHF_MASKOS =            0x0f00000
+SHF_MASKPROC =          0xf000000
+
+STN_UNDEF = 0
+
+
+class ElfSymbolBinding(SymbolicConstant):
+  _symbolics = {}
+STB_LOCAL = ElfSymbolBinding(0, "LOCAL")
+STB_GLOBAL = ElfSymbolBinding(1, "GLOBAL")
+STB_WEAK = ElfSymbolBinding(2, "WEAK")
+
+
+class ElfSymbolType(SymbolicConstant):
+  _symbolics = {}
+STT_NOTYPE = ElfSymbolType(0, "NOTYPE")
+STT_OBJECT = ElfSymbolType(1, "OBJECT")
+STT_FUNC = ElfSymbolType(2, "FUNC")
+STT_SECTION = ElfSymbolType(3, "SECTION")
+STT_FILE = ElfSymbolType(4, "FILE")
+STT_COMMON = ElfSymbolType(5, "COMMON")
+STT_TLS = ElfSymbolType(6, "TLS")
+
+
+class ElfSymbolVisibility(SymbolicConstant):
+  _symbolics = {}
+STV_DEFAULT = ElfSymbolVisibility(0, "DEFAULT")
+STV_INTERNAL = ElfSymbolVisibility(1, "INTERN")
+STV_HIDDEN = ElfSymbolVisibility(2, "HIDDEN")
+STV_PROTECTED = ElfSymbolVisibility(3, "PROTECTED")
+
+
+class ElfPhType(SymbolicConstant):
+  _symbolics = {}
+PT_NULL = ElfPhType(0, "NULL")
+PT_LOAD = ElfPhType(1, "LOAD")
+PT_DYNAMIC = ElfPhType(2, "DYNAMIC")
+PT_INTERP = ElfPhType(3, "INTERP")
+PT_NOTE = ElfPhType(4, "NOTE")
+PT_SHLIB = ElfPhType(5, "SHLIB")
+PT_PHDR = ElfPhType(6, "PHDR")
+PT_TLS = ElfPhType(7, "TLS")
+
+PF_X = (1 << 0)
+PF_W = (1 << 1)
+PF_R = (1 << 2)
+
+class ElfDynamicType(SymbolicConstant):
+  _symbolics = {}
+  _default = "Unknown (0x%x)"
+DT_NULL = ElfDynamicType(0, "NULL")
+DT_NEEDED = ElfDynamicType(1, "NEEDED")
+DT_PLTRELSZ = ElfDynamicType(2, "PLTRELSZ")
+DT_PLTGOT = ElfDynamicType(3, "PLTGOT")
+DT_HASH = ElfDynamicType(4, "HASH")
+DT_STRTAB = ElfDynamicType(5, "STRTAB")
+DT_SYMTAB = ElfDynamicType(6, "SYMTAB")
+DT_RELA = ElfDynamicType(7, "RELA")
+DT_RELASZ = ElfDynamicType(8, "RELASZ")
+DT_RELAENT = ElfDynamicType(9, "RELAENT")
+DT_STRSZ = ElfDynamicType(10, "STRSZ")
+DT_SYMENT = ElfDynamicType(11, "SYMENT")
+DT_INIT = ElfDynamicType(12, "INIT")
+DT_FINI = ElfDynamicType(13, "FINI")
+DT_SONAME = ElfDynamicType(14, "SONAME")
+DT_RPATH = ElfDynamicType(15, "RPATH")
+DT_SYMBOLIC = ElfDynamicType(16, "SYMBOLIC")
+DT_REL = ElfDynamicType(17, "REL")
+DT_RELSZ = ElfDynamicType(18, "RELSZ")
+DT_RELENT = ElfDynamicType(19, "RELENT")
+DT_PLTREL = ElfDynamicType(20, "PLTREL")
+DT_DEBUG = ElfDynamicType(21, "DEBUG")
+DT_TEXTREL = ElfDynamicType(22, "TEXTREL")
+DT_JMPREL = ElfDynamicType(23, "JMPREL")
+DT_BIND_NOW = ElfDynamicType(24, "BIND_NOW")
+DT_INIT_ARRAY = ElfDynamicType(25, "INIT_ARRAY")
+DT_FINI_ARRAY = ElfDynamicType(26, "FINI_ARRAY")
+DT_INIT_ARRAYSZ = ElfDynamicType(27, "INIT_ARRAYSZ")
+DT_FINI_ARRAYSZ = ElfDynamicType(28, "FINI_ARRAYSZ")
+DT_RUNPATH = ElfDynamicType(29, "RUNPATH")
+DT_FLAGS = ElfDynamicType(30, "FLAGS")
+DT_ENCODING = ElfDynamicType(31, "ENCODING")
+DT_PREINIT_ARRAY = ElfDynamicType(32, "PREINIT_ARRAY")
+DT_PREINIT_ARRAYSZ = ElfDynamicType(33, "PREINIT_ARRAYSZ")
+
+# AMD x86-64 relocations
+class Amd64Relocation(SymbolicConstant):
+  _symbolics = {}
+
+R_X86_64_NONE = Amd64Relocation(0, "NONE")
+R_X86_64_64 = Amd64Relocation(1, "64")
+R_X86_64_PC32 = Amd64Relocation(2, "PC32")
+R_X86_64_GOT32 = Amd64Relocation(3, "GOT32")
+R_X86_64_PLT32 = Amd64Relocation(4, "PLT32")
+R_X86_64_COPY = Amd64Relocation(5, "COPY")
+R_X86_64_GLOB_DAT = Amd64Relocation(6, "GLOB_DAT")
+R_X86_64_JUMP_SLOT = Amd64Relocation(7, "JUMP_SLOT")
+R_X86_64_RELATIVE = Amd64Relocation(8, "RELATIVE")
+R_X86_64_GOTPCREL = Amd64Relocation(9, "GOTPCREL")
+R_X86_64_32 = Amd64Relocation(10, "32")
+R_X86_64_32S = Amd64Relocation(11, "32S")
+R_X86_64_16 = Amd64Relocation(12, "16")
+R_X86_64_PC16 = Amd64Relocation(13, "PC16")
+R_X86_64_8 = Amd64Relocation(14, "8")
+R_X86_64_PC8 = Amd64Relocation(15, "PC8")
+R_X86_64_DTPMOD64 = Amd64Relocation(16, "DTPMOD64")
+R_X86_64_DTPOFF64 = Amd64Relocation(17, "DTPOFF64")
+R_X86_64_TPOFF64 = Amd64Relocation(18, "TPOFF64")
+R_X86_64_TLSGD = Amd64Relocation(19, "TLSGD")
+R_X86_64_TLSLD = Amd64Relocation(20, "TLSLD")
+R_X86_64_DTPOFF32 = Amd64Relocation(21, "DTPOFF32")
+R_X86_64_GOTTPOFF = Amd64Relocation(22, "GOTTPOFF")
+R_X86_64_TPOFF32 = Amd64Relocation(23, "TPOFF32")
+  
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/elf/elf.py b/elf/elf.py
new file mode 100644 (file)
index 0000000..d90e81e
--- /dev/null
@@ -0,0 +1,845 @@
+# -*- coding: utf-8 -*-
+
+# kate: space-indent on; indent-width 2; mixedindent off; indent-mode python;
+
+# Copyright (C) 2009 Amand 'alrj' Tihon <amand.tihon@alrj.org>
+#
+# This file is part of bold, the Byte Optimized Linker.
+# Heavily inspired by elf.h from the GNU C Library.
+#
+# You can redistribute this file and/or modify it under the terms of the
+# GNU Lesser General Public License as published by the Free Software
+# Foundation, version 2.1.
+
+
+from BinArray import BinArray
+from constants import *
+import struct
+
+# Helpful decorator
+def nested_property(c):
+  return property(**c())
+
+#--------------------------------------------------------------------------
+#  Elf
+#--------------------------------------------------------------------------
+
+class Elf64(object):
+  """Handles an Elf64 object."""
+  interpreter = "/lib64/ld-linux-x86-64.so.2"
+
+  def __init__(self, path=None):
+    object.__init__(self)
+    self.header = Elf64_Ehdr()
+    self.header.owner = self
+    self.shdrs = []
+    self.phdrs = []
+    self.shlibs = []
+    self.sections = {}
+    self.segments = []
+    self.local_symbols = {}
+    self.global_symbols = {}
+    self.undefined_symbols = []
+
+    if path:
+      self.fromfile(path)
+
+  def fromfile(self, path):
+    f = file(path, "rb")
+
+    # Load Elf header
+    data = BinArray()
+    data.fromfile(f, Elf64_Ehdr.size)
+    self.header.fromBinArray(data)
+
+    # Load sections headers
+    f.seek(self.header.e_shoff)
+    for i in range(self.header.e_shnum):
+      data = BinArray()
+      data.fromfile(f, self.header.e_shentsize)
+      h = Elf64_Shdr(i, data)
+      h.owner = self
+      self.shdrs.append(h)
+
+    # Read sections content
+    for sh in self.shdrs:
+      data = BinArray()
+      if sh.sh_type != SHT_NOBITS:
+        f.seek(sh.sh_offset)
+        data.fromfile(f, sh.sh_size)
+      sh.content = data
+
+    f.close()
+
+  def resolve_names(self):
+    # The .shstrtab index is in Elf Header. find the sections names
+    strtab = self.shdrs[self.header.e_shstrndx].content
+
+    for sh in self.shdrs:
+      sh.name = strtab[int(sh.sh_name)]
+      self.sections[sh.name] = sh
+
+      # And resolve names in the section itself
+      sh.resolve_names()
+
+
+  def find_symbols(self):
+    for sh in self.shdrs:
+      if sh.sh_type == SHT_SYMTAB:
+        symtab = sh.content.symtab
+
+        for symbol in symtab:
+          if symbol.st_type == STT_FILE:
+            continue
+          if symbol.st_shndx == SHN_ABS:
+            continue
+          if symbol.st_shndx == SHN_UNDEF:
+            if symbol.name:
+              self.undefined_symbols.append(symbol.name)
+            continue
+
+          target_section = self.shdrs[symbol.st_shndx]
+
+          symbol_name = symbol.name
+          value = symbol.st_value
+          bind = symbol.st_binding
+
+          # We got a name, a target section, and an offset in the section
+          if symbol.st_binding == STB_LOCAL:
+            if symbol.st_type == STT_SECTION:
+              symbol_name = target_section.name
+            self.local_symbols[symbol_name] = (target_section, value)
+          else:
+            self.global_symbols[symbol_name] = (target_section, value)
+
+  def apply_relocation(self, all_global_symbols):
+    # find relocation tables
+    relocations = [sh for sh in self.shdrs if sh.sh_type in [SHT_REL, SHT_RELA]]
+    for sh in relocations:
+      target = sh.target.content
+
+      for reloc in sh.content.relatab:
+        
+        if reloc.symbol.st_shndx == SHN_UNDEF:
+          # This is an extern symbol, find it in all_global_symbols
+          sym_address = all_global_symbols[reloc.symbol.name]
+          print "0x%x" % sym_address
+        else:
+          # source == in which section it is defined
+          source = self.shdrs[reloc.symbol.st_shndx].content
+          sym_address = source.virt_addr + reloc.symbol.st_value
+
+        target_ba = target.data # The actual BinArray that we'll modify
+        pc_address = target.virt_addr + reloc.r_offset
+
+        if reloc.r_type == R_X86_64_64:
+          format = "<Q" # Direct 64 bit address
+          target_value = sym_address + reloc.r_addend
+        elif reloc.r_type == R_X86_64_PC32:
+          format = "<i" # PC relative 32 bit signed
+          target_value = sym_address + reloc.r_addend - pc_address
+        elif reloc.r_type == R_X86_64_32:
+          format = "<I" # Direct 32 bit zero extended
+          target_value = sym_address + reloc.r_addend
+        elif reloc.r_type == R_X86_64_PC16:
+          format = "<h" # 16 bit sign extended pc relative
+          target_value = sym_address + reloc.r_addend - pc_address
+        elif reloc.r_type == R_X86_64_16:
+          format = "<H" # Direct 16 bit zero extended
+          target_value = sym_address + reloc.r_addend
+        elif reloc.r_type == R_X86_64_PC8:
+          format = "b" # 8 bit sign extended pc relative
+          target_value = sym_address + reloc.r_addend - pc_address
+        elif reloc.r_type == R_X86_64_8:
+          format = "b" # Direct 8 bit sign extended
+          target_value = sym_address + reloc.r_addend
+        else:
+          print "Unsupported relocation type: %s" % reloc.r_type
+          exit(1)
+
+        d = BinArray(struct.pack(format, target_value))
+        start = reloc.r_offset
+        end = start + len(d)
+        target_ba[start:end] = d
+
+
+  def add_phdr(self, phdr):
+    self.phdrs.append(phdr)
+    self.header.e_phnum = len(self.phdrs)
+    phdr.owner = self
+
+  def add_segment(self, segment):
+    self.segments.append(segment)
+
+  def layout(self, base_vaddr):
+    """Do the actual layout for final executable."""
+
+    virt_addr = base_vaddr
+    file_offset = 0
+    self.virt_addr = base_vaddr
+    self.file_offset = file_offset
+    for s in self.segments:
+        virt_addr += s.align
+        s.virt_addr = virt_addr
+        s.file_offset = file_offset
+        s.layout()
+        virt_addr += s.logical_size
+        file_offset += s.physical_size
+
+  def toBinArray(self):
+    ba = BinArray()
+    for s in self.segments:
+      ba.extend(s.toBinArray())
+    return ba
+
+
+#--------------------------------------------------------------------------
+#  Elf file header
+#--------------------------------------------------------------------------
+
+class Elf64_eident(object):
+  """Detailed representation for the Elf identifier."""
+  format = "16B"
+  size = struct.calcsize(format)
+  physical_size = size
+  logical_size = size
+
+  def __init__(self, rawdata=None):
+    object.__init__(self)
+    if rawdata:
+      self.fromBinArray(rawdata)
+
+  def fromBinArray(self, rawdata):
+    t = struct.unpack(self.format, rawdata)
+    self.ei_magic = rawdata[:4]
+    self.ei_class = ElfClass(rawdata[4])
+    self.ei_data = ElfData(rawdata[5])
+    self.ei_version = ElfVersion(rawdata[6])
+    self.ei_osabi = ElfOsAbi(rawdata[7])
+    self.ei_abiversion = 0
+    self.ei_pad = [0, 0, 0, 0, 0, 0, 0]
+
+  def make_default_amd64(self):
+    self.ei_magic = BinArray([0x7f, 0x45, 0x4c, 0x46])
+    self.ei_class = ELFCLASS64
+    self.ei_data = ELFDATA2LSB
+    self.ei_version = EV_CURRENT
+    self.ei_osabi = ELFOSABI_SYSV
+    self.ei_abiversion = 0
+    self.ei_pad = [0, 0, 0, 0, 0, 0, 0]
+
+  def toBinArray(self):
+    ba = BinArray(self.ei_magic)
+    ba.append(self.ei_class)
+    ba.append(self.ei_data)
+    ba.append(self.ei_version)
+    ba.append(self.ei_osabi)
+    ba.append(self.ei_abiversion)
+    ba.extend(self.ei_pad)
+    return ba
+
+
+class Elf64_Ehdr(object):
+  """Elf file header"""
+  format = "<16B 2H I 3Q I 6H"
+  size = struct.calcsize(format)
+  physical_size = size
+  logical_size = size
+  
+  def __init__(self, rawdata=None):
+    object.__init__(self)
+    self.e_ident = Elf64_eident()
+    self.e_type = ET_NONE
+    self.e_machine = EM_X86_64
+    self.e_version = EV_CURRENT
+    self.e_entry = 0
+    self.e_phoff = 0
+    self.e_shoff = 0
+    self.e_flags = 0
+    self.e_ehsize = self.size
+    self.e_phentsize = Elf64_Phdr.size
+    self.e_phnum = 0
+    self.e_shentsize = Elf64_Shdr.size
+    self.e_shnum = 0
+    self.e_shstrndx = 0
+    if rawdata:
+      self.fromBinArray(rawdata)
+
+  def fromBinArray(self, rawdata):
+    t = struct.unpack(self.format, rawdata)
+    self.e_ident = Elf64_eident(BinArray(rawdata[:16]))
+    self.e_type = ElfType(t[16])
+    self.e_machine = ElfMachine(t[17])
+    self.e_version = ElfVersion(t[18])
+    self.e_entry = t[19]
+    self.e_phoff = t[20]
+    self.e_shoff = t[21]
+    self.e_flags = t[22]
+    self.e_ehsize = t[23]
+    self.e_phentsize = t[24]
+    self.e_phnum = t[25]
+    self.e_shentsize = t[26]
+    self.e_shnum = t[27]
+    self.e_shstrndx = t[28]
+
+  def toBinArray(self):
+    # Build a list from e_ident and all other fields, to feed struct.pack.
+    values = self.e_ident.toBinArray().tolist()
+    values.extend([self.e_type, self.e_machine, self.e_version, self.e_entry,
+      self.e_phoff, self.e_shoff, self.e_flags, self.e_ehsize, self.e_phentsize,
+      self.e_phnum, self.e_shentsize, self.e_shnum, self.e_shstrndx])
+    res = struct.pack(self.format, *values)
+    return BinArray(res)
+
+  def layout(self):
+    pass
+
+
+#--------------------------------------------------------------------------
+#  Elf Sections
+#--------------------------------------------------------------------------
+
+class Elf64_Shdr(object):
+  """Elf64 section header."""
+  format = "<2I 4Q 2I 2Q"
+  size = struct.calcsize(format)
+  physical_size = size
+  logical_size = size
+  
+  def __init__(self, index=None, rawdata=None):
+    object.__init__(self)
+    self.index = index
+    if rawdata:
+      self.fromBinArray(rawdata)
+
+  def fromBinArray(self, rawdata):
+    t = struct.unpack(self.format, rawdata)
+    self.sh_name = t[0]
+    self.sh_type = ElfShType(t[1])
+    self.sh_flags = t[2]
+    self.sh_addr = t[3]
+    self.sh_offset = t[4]
+    self.sh_size = t[5]
+    self.sh_link = t[6]
+    self.sh_info = t[7]
+    self.sh_addralign = t[8]
+    self.sh_entsize = t[9]
+
+  def resolve_names(self):
+    self.content.resolve_names(self.owner)
+
+  @nested_property
+  def content():
+    def fget(self):
+      return self._content
+    def fset(self, data):
+      """Use the Section factory to get the subclass corresponding to the
+         session type specified in this header)."""
+      self._content = Section(self, data)
+    return locals()
+
+# For sections that contain elements of specific types :
+
+class Elf64_Sym(object):
+  """Symbol Table entry"""
+  format = "<I 2B H 2Q "
+  entsize = struct.calcsize(format)
+  def __init__(self, rawdata=None):
+    object.__init__(self)
+    if rawdata:
+      self.fromBinArray(rawdata)
+
+  @nested_property
+  def st_binding():
+    def fget(self):
+      return ElfSymbolBinding((self.st_info >> 4) & 0x0f)
+    def fset(self, value):
+      self.st_info = (((value & 0x0f) << 4) | (self.st_info & 0x0f))
+    return locals()
+
+  @nested_property
+  def st_type():
+    def fget(self):
+       return ElfSymbolType(self.st_info & 0x0f)
+    def fset(self, value):
+      self.st_info = ((self.st_info & 0xf0) | (value & 0x0f))
+    return locals()
+
+  @nested_property
+  def st_visibility():
+    def fget(self):
+      return ElfSymbolVisibility(self.st_other & 0x03)
+    def fset(self, value):
+      self.st_other = ((self.st_other & 0xfc) | (value & 0x03))
+    return locals()
+
+  def fromBinArray(self, rawdata):
+    t = struct.unpack(self.format, rawdata)
+    self.st_name = t[0] # index in the strtab pointed by sh_link
+    self.st_info = t[1]
+    self.st_other = t[2]
+    self.st_shndx = ElfSectionIndex(t[3])
+    self.st_value = t[4]
+    self.st_size = t[5]
+
+
+class Elf64_Rel(object):
+  format = "<2Q"
+  def __init__(self, rawdata=None):
+    object.__init__(self)
+    self.r_addend = 0 # No addend in a Rel.
+    if rawdata:
+      self.fromBinArray(rawdata)
+
+  def fromBinArray(sef, rawdata):
+    t = struct.unpack(self.format, rawdata)
+    self.r_offset = t[0]
+    self.r_info = t[1]
+
+  @nested_property
+  def r_sym():
+    def fget(self):
+      return (self.r_info >> 32) & 0xffffffff
+    def fset(self, value):
+      self.r_info = ((value & 0xffffffff) << 32) | (self.r_info & 0xffffffff)
+    return locals()
+
+  @nested_property
+  def r_type():
+    def fget(self):
+      return Amd64Relocation(self.r_info & 0xffffffff)
+    def fset(self, value):
+      self.r_info = (self.r_info & 0xffffffff00000000) | (value & 0xffffffff)
+    return locals()
+
+
+class Elf64_Rela(Elf64_Rel):
+  format = "<2Q q"
+  def __init__(self, rawdata=None):
+    Elf64_Rel.__init__(self, rawdata)
+
+  def fromBinArray(self, rawdata):
+    t = struct.unpack(self.format, rawdata)
+    self.r_offset = t[0]
+    self.r_info = t[1]
+    self.r_addend = t[2]
+
+
+class Elf64_Dyn(object):
+  format = "<2Q"
+  size = struct.calcsize(format)
+  def __init__(self, tag, value):
+    object.__init__(self)
+    self.d_tag = tag
+    self.d_val = value
+
+  @nested_property
+  def d_ptr():
+    def fget(self):
+      return self.d_val
+    def fset(self, value):
+      self.d_val = value
+    return locals()
+
+
+# Sections types :
+
+def Section(shdr, data=None):
+  """A section factory"""
+  dataclass = {
+    SHT_NULL:           SNull,
+    SHT_PROGBITS:       SProgBits,
+    SHT_SYMTAB:         SSymtab,
+    SHT_STRTAB:         SStrtab,
+    SHT_RELA:           SRela,
+    SHT_HASH:           SHash,
+    SHT_DYNAMIC:        SDynamic,
+    SHT_NOTE:           SNote,
+    SHT_NOBITS:         SNobits,
+    SHT_REL:            SRel,
+    SHT_SHLIB:          SShlib,
+    SHT_DYNSYM:         SDynsym
+  }
+  if shdr.sh_type in dataclass:
+    return dataclass[shdr.sh_type](shdr, data)
+  else:
+    return BaseSection(shdr, data)
+
+
+class BaseSection(object):
+  def __init__(self, shdr, data=None):
+    object.__init__(self)
+    self.data = None
+    self.header = shdr
+    if data:
+      self.fromBinArray(data)
+
+  def fromBinArray(self, data):
+    self.data = data
+
+  def toBinArray(self):
+    if self.data:
+      return self.data
+    else:
+      return BinArray()
+
+  def resolve_names(self, elf):
+    """Nothing to resolve."""
+    pass
+
+  @nested_property
+  def size():
+    def fget(self):
+      return len(self.data)
+    return locals()
+  physical_size = size
+  logical_size = size
+
+  def layout(self):
+    pass
+
+
+class SNull(BaseSection):
+  def __init__(self, shdr, data=None):
+    BaseSection.__init__(self, shdr, None)
+
+
+class SProgBits(BaseSection):
+  def __init__(self, shdr, data=None):
+    BaseSection.__init__(self, shdr, data)
+
+
+class SSymtab(BaseSection):
+  entsize = struct.calcsize(Elf64_Sym.format)
+  def __init__(self, shdr, data=None):
+    self.symtab = []
+    BaseSection.__init__(self, shdr, data)
+
+  def fromBinArray(self, data):
+    BaseSection.fromBinArray(self, data)
+    nument = len(data) / self.entsize
+    for i in range(nument):
+      start = i * self.entsize
+      end = i * self.entsize + self.entsize
+      self.symtab.append(Elf64_Sym(data[start:end]))
+
+  def resolve_names(self, elf):
+    # For a symtab, the strtab is indicated by sh_link
+    strtab = elf.shdrs[self.header.sh_link].content
+    # Resolve for all symbols in the table
+    for sym in self.symtab:
+      sym.name = strtab[sym.st_name]
+
+  def __getitem__(self, key):
+    return self.symtab[key]
+
+
+class SStrtab(BaseSection):
+  def __init__(self, shdr, data=None):
+    self.strtab = {}
+    BaseSection.__init__(self, shdr, data)
+
+  def fromBinArray(self, data):
+    BaseSection.fromBinArray(self, data)
+    itab = data.tostring().split('\0')
+    i = 0
+    for sname in itab:
+      self.strtab[i] = sname
+      i += len(sname) + 1
+
+  def __getitem__(self, key):
+    if key in self.strtab:
+      return self.strtab[key]
+    else:
+      v = self.data[key:].tostring().split('\0')[0]
+      self.strtab[key] = v
+      return v
+
+  def iteritems(self):
+    return self.strtab.iteritems()
+
+
+class SRela(BaseSection):
+  entsize = struct.calcsize(Elf64_Rela.format)
+  def __init__(self, shdr, data=None):
+    self.relatab = []
+    BaseSection.__init__(self, shdr, data)
+
+  def fromBinArray(self, data):
+    BaseSection.fromBinArray(self, data)
+    nument = len(data) / self.entsize
+    for i in range(nument):
+      start = i * self.entsize
+      end = i * self.entsize + self.entsize
+      self.relatab.append(Elf64_Rela(data[start:end]))
+
+  def resolve_names(self, elf):
+    """Badly named, this wil resolve to a symtab entry..."""
+    # sh_link leads to the symtab
+    self.symtab = elf.shdrs[self.header.sh_link].content
+    # sh_info links to the section on which the relocation applies
+    self.header.target = elf.shdrs[self.header.sh_info]
+    for r in self.relatab:
+      r.symbol = self.symtab[r.r_sym]
+      
+    
+
+class SHash(BaseSection):
+  pass
+
+
+class SDynamic(BaseSection):
+  pass
+
+
+class SNote(BaseSection):
+  pass
+
+
+class SNobits(BaseSection):
+  size = 0
+  physical_size = 0
+
+  @nested_property
+  def logical_size():
+    def fget(self):
+      return self.header.sh_size
+    return locals()
+
+  def toBinArray(self):
+    return BinArray()
+
+class SRel(BaseSection):
+  pass
+
+
+class SShlib(BaseSection):
+  pass
+
+
+class SDynsym(SSymtab):
+  pass
+
+
+class Elf64_Phdr(object):
+  format = "<2I 6Q"
+  size = struct.calcsize(format)
+  physical_size = size
+  logical_size = size
+
+  def __init__(self):
+    object.__init__(self)
+    self.p_type = PT_NULL
+    self.p_flags = PF_X + PF_W + PF_R
+    self.p_offset = 0
+    self.p_vaddr = 0
+    self.p_paddr = 0
+    self.p_filesz = 0
+    self.p_memsz = 0
+    self.p_align = 1
+    #self.content = []
+    #self.nobits = []
+
+  def toBinArray(self):
+    res = struct.pack(self.format, self.p_type, self.p_flags, self.p_offset,
+      self.p_vaddr, self.p_paddr, self.p_filesz, self.p_memsz, self.p_align)
+    return BinArray(res)
+
+  def layout(self):
+    pass
+
+  #def add_content(self, content):
+  #  self.content.append(content)
+
+  #def add_empty_content(self, content):
+  #  self.nobits.append(content)
+
+  #@nested_property
+  #def content_size():
+  #  def fget(self):
+  #    return sum(s.sh_size for s in self.content)
+  #  return locals()
+
+
+class BaseSegment(object):
+  def __init__(self, align=0):
+    object.__init__(self)
+    self.align = align
+    self.content = []
+
+  def add_content(self, content):
+    self.content.append(content)
+
+  def toBinArray(self):
+    ba = BinArray()
+    for c in self.content:
+      ba.extend(c.toBinArray())
+    return ba
+
+  @nested_property
+  def size():
+    def fget(self):
+      return sum(c.size for c in self.content)
+    return locals()
+  physical_size = size
+  logical_size = size
+
+
+class TextSegment(BaseSegment):
+  def __init__(self, align=0):
+    BaseSegment.__init__(self, align)
+
+  def layout(self):
+    virt_addr = self.virt_addr
+    file_offset = self.file_offset
+    for i in self.content:
+      i.virt_addr = virt_addr
+      i.file_offset = file_offset
+      i.layout()
+      virt_addr += i.logical_size
+      file_offset += i.physical_size
+
+
+class DataSegment(BaseSegment):
+  def __init__(self, align=0):
+    BaseSegment.__init__(self, align)
+    self.nobits = []
+
+  def add_nobits(self, content):
+    self.nobits.append(content)
+
+  def layout(self):
+    virt_addr = self.virt_addr
+    file_offset = self.file_offset
+    for i in self.content:
+      i.virt_addr = virt_addr
+      i.file_offset = file_offset
+      i.layout()
+      virt_addr += i.logical_size
+      file_offset += i.physical_size
+    for i in self.nobits:
+      i.virt_addr = virt_addr
+      i.file_offset = 0
+      i.layout()
+      virt_addr += i.logical_size
+
+  @nested_property
+  def logical_size():
+    def fget(self):
+      return self.physical_size + sum(c.logical_size for c in self.nobits)
+    return locals()
+
+
+
+class PStrtab(object):
+  def __init__(self):
+    object.__init__(self)
+    self.table = []
+    self.virt_addr = None
+
+  def append(self, string):
+    if len(self.table):
+      offset = self.table[-1][0]
+      offset += len(self.table[-1][1])
+    else:
+      offset = 0
+    new_str = string + '\0'
+    self.table.append((offset, new_str))
+    return offset
+
+  @nested_property
+  def size():
+    def fget(self):
+      return (self.table[-1][0] + len(self.table[-1][1]))
+    return locals()
+  physical_size = size
+  logical_size = size
+
+  def toBinArray(self):
+    ba = BinArray()
+    for s in (i[1] for i in self.table):
+      ba.fromstring(s)
+    return ba
+
+  def layout(self):
+    pass
+
+
+class Dynamic(object):
+  def __init__(self):
+    object.__init__(self)
+    self.dyntab = []
+    self.strtab = PStrtab()
+
+  @nested_property
+  def size():
+    def fget(self):
+      # End the table with a DT_NULL without associated value.
+      return (Elf64_Dyn.size * len(self.dyntab) + struct.calcsize("Q"))
+    return locals()
+  physical_size = size
+  logical_size = size
+
+  def add_shlib(self, shlib):
+    offset = self.strtab.append(shlib)
+    self.dyntab.append((DT_NEEDED, offset))
+
+  def add_symtab(self, vaddr):
+    self.dyntab.append((DT_SYMTAB, vaddr))
+
+  def add_debug(self):
+    self.dyntab.append((DT_DEBUG, 0))
+
+  def layout(self):
+    # Adjust the address of the strtab, if 
+    if self.strtab.virt_addr is None:
+      print "Ooops, strtab's address is not known yet. Aborting."
+      exit(1)
+    else:
+      self.dyntab.append((DT_STRTAB, self.strtab.virt_addr))
+
+  @nested_property
+  def dt_debug_address():
+    def fget(self):
+      for i, d in enumerate(self.dyntab):
+        if d[0] == DT_DEBUG:
+          return self.virt_addr + (i*16 + 8)
+    return locals()
+    
+
+  def toBinArray(self):
+    ba = BinArray()
+    for i in self.dyntab:
+      s = struct.pack("<2Q", i[0], i[1])
+      ba.fromstring(s)
+    null = struct.pack("<Q", DT_NULL)
+    ba.fromstring(null)
+    return ba
+
+
+class Interpreter(object):
+  default_interpreter = "/lib64/ld-linux-x86-64.so.2"
+
+  def __init__(self, interpreter=None):
+    object.__init__(self)
+    if interpreter:
+      self.interpreter = interpreter
+    else:
+      self.interpreter = self.default_interpreter
+
+  @nested_property
+  def size():
+    def fget(self):
+      # Null terminated
+      return len(self.interpreter) + 1
+    return locals()
+  physical_size = size
+  logical_size = size
+
+  def toBinArray(self):
+    ba = BinArray(self.interpreter)
+    ba.append(0)
+    return ba
+
+  def layout(self):
+    pass