Root/lib/crc32defs.h

1/*
2 * There are multiple 16-bit CRC polynomials in common use, but this is
3 * *the* standard CRC-32 polynomial, first popularized by Ethernet.
4 * 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
5 */
6#define CRCPOLY_LE 0xedb88320
7#define CRCPOLY_BE 0x04c11db7
8
9/* How many bits at a time to use. Requires a table of 4<<CRC_xx_BITS bytes. */
10/* For less performance-sensitive, use 4 */
11#ifndef CRC_LE_BITS
12# define CRC_LE_BITS 8
13#endif
14#ifndef CRC_BE_BITS
15# define CRC_BE_BITS 8
16#endif
17
18/*
19 * Little-endian CRC computation. Used with serial bit streams sent
20 * lsbit-first. Be sure to use cpu_to_le32() to append the computed CRC.
21 */
22#if CRC_LE_BITS > 8 || CRC_LE_BITS < 1 || CRC_LE_BITS & CRC_LE_BITS-1
23# error CRC_LE_BITS must be a power of 2 between 1 and 8
24#endif
25
26/*
27 * Big-endian CRC computation. Used with serial bit streams sent
28 * msbit-first. Be sure to use cpu_to_be32() to append the computed CRC.
29 */
30#if CRC_BE_BITS > 8 || CRC_BE_BITS < 1 || CRC_BE_BITS & CRC_BE_BITS-1
31# error CRC_BE_BITS must be a power of 2 between 1 and 8
32#endif
33

Archive Download this file



interactive