This function implements a 32 bit CRC which is compliant to the POSIX 1008.2 Standard. This is the same as the Linux cksum program.

cyg_uint32 cyg_posix_crc32(unsigned char * s, int len);

The CRC calculation is run over the data pointed to by s, of length len. The CRC is returned as an unsigned long.

These functions implement a 32 bit CRC by Gary S. Brown. They use the polynomial 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.

cyg_uint32 cyg_crc32(unsigned char * s, int len);
cyg_uint32 cyg_crc32_accumulate(cyg_uint32 crc, unsigned char * s, int len);

The CRC calculation is run over the data pointed to by s, of length len. The CRC is returned as an unsigned long.

The CRC can be calculated over data separated into multiple buffers by using the function cyg_crc32_accumulate(). The parameter crc should be the result from the previous CRC calculation.

These functions implement the 32 bit CRC used by the Ethernet FCS word.

cyg_uint32 cyg_ether_crc32(unsigned char * s, int len);
cyg_uint32 cyg_ether_crc32_accumulate(cyg_uint32 crc, unsigned char * s, int len);

The CRC calculation is run over the data pointed to by s, of length len. The CRC is returned as an unsigned long.

The CRC can be calculated over data separated into multiple buffers by using the function cyg_ether_crc32_accumulate(). The parameter crc should be the result from the previous CRC calculation.

This function implements a 16 bit CRC. It uses the polynomial x^16+x^12+x^5+1.

cyg_uint16 cyg_crc16(unsigned char * s, int len);

The CRC calculation is run over the data pointed to by s, of length len. The CRC is returned as an unsigned short.