#!/usr/bin/env python3

# Copyright (C) 2024 Herbert Poetzl

import sys
import re

def read_usr_access(filename):
  rev = False

  with open(filename, "rb") as fp:
    data = fp.read()

  # Search for pattern preceding USR_ACCESS value
  match = re.findall(br"\x30\x01\xA0\x01(.{4})", data)

  if not match:
      match = re.findall(br"\x01\xA0\x01\x30(.{4})", data)
      rev = True

  if not match:
    return None

  # Extract and convert 4 bytes to integer
  usr_access_bytes = match[0]
  usr_access_value = int.from_bytes(usr_access_bytes,
        byteorder="little" if rev else "big", signed=False)

  # print(f"USR_ACCESS register (little-endian): {usr_access_value}")
  return usr_access_value


value = read_usr_access(sys.argv[1])

if value is not None:
    print(f"USR_ACCESS register value: 0x{value:08X}")
else:
  print("USR_ACCESS register not found in the file.")