projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 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 | ||
| 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 |