diff options
Diffstat (limited to 'drivers/mtd/ubi/crc32defs.h')
-rw-r--r-- | drivers/mtd/ubi/crc32defs.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/mtd/ubi/crc32defs.h b/drivers/mtd/ubi/crc32defs.h new file mode 100644 index 0000000..f5a5401 --- /dev/null +++ b/drivers/mtd/ubi/crc32defs.h @@ -0,0 +1,32 @@ +/* + * 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. Requires a table of 4<<CRC_xx_BITS bytes. */ +/* For less performance-sensitive, use 4 */ +#ifndef CRC_LE_BITS +# define CRC_LE_BITS 8 +#endif +#ifndef CRC_BE_BITS +# define CRC_BE_BITS 8 +#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 > 8 || CRC_LE_BITS < 1 || CRC_LE_BITS & CRC_LE_BITS-1 +# error CRC_LE_BITS must be a power of 2 between 1 and 8 +#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 > 8 || CRC_BE_BITS < 1 || CRC_BE_BITS & CRC_BE_BITS-1 +# error CRC_BE_BITS must be a power of 2 between 1 and 8 +#endif |