botw/tools/util/elf.py

79 lines
2.2 KiB
Python

#!/usr/bin/env python3
from typing import Any, Dict, NamedTuple
from elftools.elf.elffile import ELFFile
import diff_settings
from util import utils
_config: Dict[str, Any] = {}
diff_settings.apply(_config, {})
_root = utils.get_repo_root()
base_elf = ELFFile((_root / _config["baseimg"]).open("rb"))
my_elf = ELFFile((_root / _config["myimg"]).open("rb"))
my_symtab = my_elf.get_section_by_name(".symtab")
if not my_symtab:
utils.fail(f'{_config["myimg"]} has no symbol table')
class Symbol(NamedTuple):
addr: int
name: str
size: int
class Function(NamedTuple):
data: bytes
addr: int
def get_file_offset(elf, addr: int) -> int:
for seg in elf.iter_segments():
if seg.header["p_type"] != "PT_LOAD":
continue
if seg["p_vaddr"] <= addr < seg["p_vaddr"] + seg["p_filesz"]:
return addr - seg["p_vaddr"] + seg["p_offset"]
assert False
def get_symbol(table, name: str) -> Symbol:
syms = table.get_symbol_by_name(name)
if not syms or len(syms) != 1:
raise KeyError(name)
return Symbol(syms[0]["st_value"], name, syms[0]["st_size"])
def get_symbol_file_offset_and_size(elf, table, name: str) -> (int, int):
sym = get_symbol(table, name)
return get_file_offset(elf, sym.addr), sym.size
def build_addr_to_symbol_table(symtab) -> Dict[int, str]:
table = dict()
for sym in symtab.iter_symbols():
addr = sym["st_value"]
existing_value = table.get(addr, None)
if existing_value is None or not existing_value.startswith("_Z"):
table[addr] = sym.name
return table
def build_name_to_symbol_table(symtab) -> Dict[str, Symbol]:
return {sym.name: Symbol(sym["st_value"], sym.name, sym["st_size"]) for sym in symtab.iter_symbols()}
def get_fn_from_base_elf(addr: int, size: int) -> Function:
offset = get_file_offset(base_elf, addr)
base_elf.stream.seek(offset)
return Function(base_elf.stream.read(size), addr)
def get_fn_from_my_elf(name: str) -> Function:
sym = get_symbol(my_symtab, name)
offset = get_file_offset(my_elf, sym.addr)
my_elf.stream.seek(offset)
return Function(my_elf.stream.read(sym.size), sym.addr)