diff options
| -rw-r--r-- | src/include/crc_byte.h | 19 | ||||
| -rw-r--r-- | src/lib/crc_byte.c | 14 |
2 files changed, 33 insertions, 0 deletions
diff --git a/src/include/crc_byte.h b/src/include/crc_byte.h index 9315277d23..c0df5b0ce4 100644 --- a/src/include/crc_byte.h +++ b/src/include/crc_byte.h @@ -36,5 +36,24 @@ uint8_t crc7_byte(uint8_t prev_crc, uint8_t data); */ uint16_t crc16_byte(uint16_t prev_crc, uint8_t data); +/* This function is used to calculate crc32 byte by byte, with polynomial + * x^32 + x^26 + x^23 + x^22 + x^16 + x^12 + x^11 + x^10 + x^8 + x^7 + + * x^5 + x^4 + x^2 + x + 1 + * + * prev_crc: old crc result (0 for first) + * data: new byte + * return value: new crc result + */ +uint32_t crc32_byte(uint32_t prev_crc, uint8_t data); + +#define CRC(buf, size, crc_func) ({ \ + const uint8_t *_crc_local_buf = (const uint8_t *)buf; \ + size_t _crc_local_size = size; \ + __typeof__(crc_func(0, 0)) _crc_local_result = 0; \ + while (_crc_local_size--) { \ + _crc_local_result = crc_func(_crc_local_result, *_crc_local_buf++); \ + } \ + _crc_local_result; \ +}) #endif /* CRC_BYTE_H */ diff --git a/src/lib/crc_byte.c b/src/lib/crc_byte.c index 0ac006363a..c04449d13f 100644 --- a/src/lib/crc_byte.c +++ b/src/lib/crc_byte.c @@ -36,3 +36,17 @@ uint16_t crc16_byte(uint16_t prev_crc, uint8_t data) prev_crc ^= ((prev_crc & 0xff) << 4) << 1; return prev_crc; } + +uint32_t crc32_byte(uint32_t prev_crc, uint8_t data) +{ + prev_crc ^= (uint32_t)data << 24; + + for (int i = 0; i < 8; i++) { + if ((prev_crc & 0x80000000UL) != 0) + prev_crc = ((prev_crc << 1) ^ 0x04C11DB7UL); + else + prev_crc <<= 1; + } + + return prev_crc; +} |