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- /**
- * \file crc32.c
- * Functions and types for CRC checks.
- *
- * Generated on Mon Feb 21 23:02:07 2011,
- * by pycrc v0.7.1, http://www.tty1.net/pycrc/
- * using the configuration:
- * Width = 32
- * Poly = 0x04c11db7
- * XorIn = 0xffffffff
- * ReflectIn = True
- * XorOut = 0xffffffff
- * ReflectOut = True
- * Algorithm = bit-by-bit-fast
- * Direct = True
- *****************************************************************************/
- #include "crc32.h"
- #include <stdint.h>
- #include <stdlib.h>
- #include <stdbool.h>
- /**
- * Reflect all bits of a \a data word of \a data_len bytes.
- *
- * \param data The data word to be reflected.
- * \param data_len The width of \a data expressed in number of bits.
- * \return The reflected data.
- ******************************************************************************/
- uint32_t crc_reflect( uint32_t data, size_t data_len )
- {
- unsigned int i;
- uint32_t ret;
- ret = data & 0x01;
- for ( i = 1; i < data_len; i++ )
- {
- data >>= 1;
- ret = ( ret << 1 ) | ( data & 0x01 );
- }
- return ret;
- }
- /**
- * Update the crc value with new data.
- *
- * \param crc The current crc value.
- * \param data Pointer to a buffer of \a data_len bytes.
- * \param data_len Number of bytes in the \a data buffer.
- * \return The updated crc value.
- *****************************************************************************/
- uint32_t crc32_update( uint32_t crc, const unsigned char data )
- {
- unsigned int i;
- uint32_t bit;
- unsigned char c;
- c = data;
- for ( i = 0x01; i & 0xff; i <<= 1 )
- {
- bit = crc & 0x80000000;
- if ( c & i )
- {
- bit = !bit;
- }
- crc <<= 1;
- if ( bit )
- {
- crc ^= 0x04c11db7;
- }
- }
- return crc & 0xffffffff;
- }
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