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1da177e4 LT |
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 | ||
9a1dbf6a BP |
9 | /* How many bits at a time to use. Valid values are 1, 2, 4, 8, and 32. */ |
10 | /* For less performance-sensitive, use 4 or 8 */ | |
e30c7a8f | 11 | #ifndef CRC_LE_BITS |
9a1dbf6a | 12 | # define CRC_LE_BITS 32 |
1da177e4 LT |
13 | #endif |
14 | #ifndef CRC_BE_BITS | |
9a1dbf6a | 15 | # define CRC_BE_BITS 32 |
1da177e4 LT |
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 | */ | |
9a1dbf6a BP |
22 | #if CRC_LE_BITS > 32 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \ |
23 | CRC_LE_BITS & CRC_LE_BITS-1 | |
24 | # error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32}" | |
1da177e4 LT |
25 | #endif |
26 | ||
27 | /* | |
28 | * Big-endian CRC computation. Used with serial bit streams sent | |
29 | * msbit-first. Be sure to use cpu_to_be32() to append the computed CRC. | |
30 | */ | |
9a1dbf6a BP |
31 | #if CRC_BE_BITS > 32 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \ |
32 | CRC_BE_BITS & CRC_BE_BITS-1 | |
33 | # error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32}" | |
1da177e4 | 34 | #endif |