35 lines
1.1 KiB
C
35 lines
1.1 KiB
C
/*
|
|
* There are multiple 16-bit CRC polynomials in common use, but this is
|
|
* *the* standard CRC-32 polynomial, first popularized by Ethernet.
|
|
* 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+x^0
|
|
*/
|
|
#define CRCPOLY_LE 0xedb88320
|
|
#define CRCPOLY_BE 0x04c11db7
|
|
|
|
/* How many bits at a time to use. Valid values are 1, 2, 4, 8, and 32. */
|
|
/* For less performance-sensitive, use 4 or 8 */
|
|
#ifndef CRC_LE_BITS
|
|
# define CRC_LE_BITS 32
|
|
#endif
|
|
#ifndef CRC_BE_BITS
|
|
# define CRC_BE_BITS 32
|
|
#endif
|
|
|
|
/*
|
|
* Little-endian CRC computation. Used with serial bit streams sent
|
|
* lsbit-first. Be sure to use cpu_to_le32() to append the computed CRC.
|
|
*/
|
|
#if CRC_LE_BITS > 32 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \
|
|
CRC_LE_BITS & CRC_LE_BITS-1
|
|
# error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32}"
|
|
#endif
|
|
|
|
/*
|
|
* Big-endian CRC computation. Used with serial bit streams sent
|
|
* msbit-first. Be sure to use cpu_to_be32() to append the computed CRC.
|
|
*/
|
|
#if CRC_BE_BITS > 32 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \
|
|
CRC_BE_BITS & CRC_BE_BITS-1
|
|
# error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32}"
|
|
#endif
|