tools: Deduplicate code

tools/dump_function.py

@@ -1,48 +1,15 @@
 #!/usr/bin/env python3
 
 import argparse
-from elftools.elf.elffile import ELFFile
-import diff_settings
-from pathlib import Path
-from typing import Any, Dict
-import utils
 
-config: Dict[str, Any] = {}
-diff_settings.apply(config, {})
-
-root = Path(__file__).parent.parent
-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')
-
-
-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_file_offset_and_size(elf, table, name: str) -> (int, int):
-    syms = table.get_symbol_by_name(name)
-    if not syms or len(syms) != 1:
-        raise KeyError(name)
-    return get_file_offset(elf, syms[0]["st_value"]), syms[0]["st_size"]
-
-
-def get_fn_from_my_elf(name: str) -> bytes:
-    offset, size = get_symbol_file_offset_and_size(my_elf, my_symtab, name)
-    my_elf.stream.seek(offset)
-    return my_elf.stream.read(size)
+import util.elf
+from util import utils
 
 
 def dump_fn(name: str) -> None:
-    expected_dir = root / "expected"
+    expected_dir = utils.get_repo_root() / "expected"
     try:
-        fn = get_fn_from_my_elf(name)
+        fn = util.elf.get_fn_from_my_elf(name)
         path = expected_dir / f"{name}.bin"
         path.parent.mkdir(exist_ok=True)
         path.write_bytes(fn)