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# This file is part of PeachPy package and is licensed under the Simplified BSD license.
# See license.rst for the full text of the license.
class Image:
def __init__(self, abi, source=None):
from peachpy.formats.elf.section import null_section, StringSection, SymbolSection, SectionIndex
from peachpy.formats.elf.symbol import Symbol, SymbolBinding, SymbolType
self.abi = abi
self.shstrtab = StringSection(".shstrtab")
self.strtab = StringSection(".strtab")
self.symtab = SymbolSection(string_table=self.strtab)
self.sections = [null_section, self.shstrtab, self.strtab, self.symtab]
self._section_names = set([self.shstrtab.name, self.strtab.name, self.symtab.name])
if source:
source_symbol = Symbol()
source_symbol.value = 0
source_symbol.binding = SymbolBinding.local
source_symbol.type = SymbolType.file
source_symbol.name = source
source_symbol.size = 0
source_symbol.section = SectionIndex.absolute
self.symtab.add(source_symbol)
def add_section(self, section):
from peachpy.formats.elf.section import Section
if not isinstance(section, Section):
raise TypeError("%s is not a Section object" % str(section))
if section.name is not None and section.name in self._section_names:
raise ValueError("Section %s is already present in the image" % section.name)
self.sections.append(section)
self._section_names.add(section.name)
def find_section(self, section_name):
for section in self.sections:
if section.name == section_name:
return section
@property
def as_bytearray(self):
import six
from peachpy.formats.elf.file import FileHeader
from peachpy.formats.elf.section import Section, StringSection, SymbolSection
from peachpy.util import roundup
file_header = FileHeader(self.abi)
file_header.section_header_table_offset = file_header.size
file_header.section_header_entries_count = len(self.sections)
file_header.section_name_string_table_index = 1
data = file_header.as_bytearray
# Collect strings from sections
for section in self.sections:
self.shstrtab.add(section.name)
if isinstance(section, StringSection):
pass
elif isinstance(section, SymbolSection):
for symbol in six.iterkeys(section.symbol_index_map):
self.strtab.add(symbol.name)
# Layout sections
data_offset = file_header.size + Section.get_header_size(self.abi) * len(self.sections)
section_offsets = []
for section in self.sections:
if section.alignment != 0:
data_offset = roundup(data_offset, section.alignment)
section_offsets.append(data_offset)
data_offset += section.get_content_size(self.abi)
from peachpy.encoder import Encoder
encoder = Encoder(self.abi.endianness, self.abi.elf_bitness)
section_index_map = {section: index for index, section in enumerate(self.sections)}
# Write section headers
for section, offset in zip(self.sections, section_offsets):
data += section.encode_header(encoder, self.shstrtab._string_index_map, section_index_map, offset)
# Write section content
for section in self.sections:
padding = bytearray(roundup(len(data), section.alignment) - len(data))
data += padding
data += section.encode_content(encoder,
self.strtab._string_index_map, section_index_map,
self.symtab.symbol_index_map)
return data
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