import struct
|
import binascii
|
|
# 下载文件
|
with open('test_data.bin', 'rb') as f:
|
data = f.read()
|
|
print(f"Total size: {len(data)} bytes")
|
print(f"First 16 bytes: {data[:16].hex()}")
|
|
# 数据部分（不包括最后4字节CRC）
|
data_only = data[:-4]
|
crc_stored = struct.unpack('<I', data[-4:])[0]
|
|
print(f"\nStored CRC32: 0x{crc_stored:08X}")
|
print(f"Data size: {len(data_only)} bytes")
|
|
# 标准CRC32（按字节流）
|
crc_standard = binascii.crc32(data_only, 0) & 0xFFFFFFFF
|
print(f"\n1. Standard CRC32 (byte stream, init=0): 0x{crc_standard:08X}")
|
|
# 模拟STM32 Word模式（32位小端）
|
# 将数据按4字节分组，每组作为32位小端整数
|
def crc32_word_mode_le(data):
|
"""模拟STM32 Word模式，小端字节序"""
|
crc = 0
|
offset = 0
|
|
# 处理完整的4字节块
|
while offset + 4 <= len(data):
|
word = struct.unpack('<I', data[offset:offset+4])[0] # 小端读取
|
word_bytes = struct.pack('<I', word) # 再转回字节
|
crc = binascii.crc32(word_bytes, crc) & 0xFFFFFFFF
|
offset += 4
|
|
# 处理剩余字节（补零对齐）
|
if offset < len(data):
|
remaining = data[offset:]
|
word_bytes = remaining + b'\x00' * (4 - len(remaining))
|
crc = binascii.crc32(word_bytes, crc) & 0xFFFFFFFF
|
|
return crc
|
|
crc_word_le = crc32_word_mode_le(data_only)
|
print(f"2. Word mode (little-endian, init=0): 0x{crc_word_le:08X}")
|
|
# 模拟STM32 Word模式（32位大端）
|
def crc32_word_mode_be(data):
|
"""模拟STM32 Word模式，大端字节序"""
|
crc = 0
|
offset = 0
|
|
# 处理完整的4字节块
|
while offset + 4 <= len(data):
|
word = struct.unpack('>I', data[offset:offset+4])[0] # 大端读取
|
word_bytes = struct.pack('>I', word) # 再转回字节
|
crc = binascii.crc32(word_bytes, crc) & 0xFFFFFFFF
|
offset += 4
|
|
# 处理剩余字节（补零对齐）
|
if offset < len(data):
|
remaining = data[offset:]
|
word_bytes = remaining + b'\x00' * (4 - len(remaining))
|
crc = binascii.crc32(word_bytes, crc) & 0xFFFFFFFF
|
|
return crc
|
|
crc_word_be = crc32_word_mode_be(data_only)
|
print(f"3. Word mode (big-endian, init=0): 0x{crc_word_be:08X}")
|
|
# 检查匹配
|
print(f"\n{'✓ MATCH!' if crc_standard == crc_stored else '✗ No match'} - Standard")
|
print(f"{'✓ MATCH!' if crc_word_le == crc_stored else '✗ No match'} - Word LE")
|
print(f"{'✓ MATCH!' if crc_word_be == crc_stored else '✗ No match'} - Word BE")
|
