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1//-----------------------------------------------------------------------------
2// This code is licensed to you under the terms of the GNU GPL, version 2 or,
3// at your option, any later version. See the LICENSE.txt file for the text of
4// the license.
5//-----------------------------------------------------------------------------
6// Generic CRC calculation code.
7//-----------------------------------------------------------------------------
8
9#ifndef __CRC_H
10#define __CRC_H
11
12#include <stdint.h>
13
14typedef struct crc {
15 uint32_t state;
16 int order;
17 uint32_t polynom;
18 uint32_t initial_value;
19 uint32_t final_xor;
20 uint32_t mask;
21} crc_t;
22
23/* Initialize a crc structure. order is the order of the polynom, e.g. 32 for a CRC-32
24 * polynom is the CRC polynom. initial_value is the initial value of a clean state.
25 * final_xor is XORed onto the state before returning it from crc_result(). */
26extern void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor);
27
28/* Update the crc state. data is the data of length data_width bits (only the the
29 * data_width lower-most bits are used).
30 */
31extern void crc_update(crc_t *crc, uint32_t data, int data_width);
32
33/* Clean the crc state, e.g. reset it to initial_value */
34extern void crc_clear(crc_t *crc);
35
36/* Get the result of the crc calculation */
37extern uint32_t crc_finish(crc_t *crc);
38
39/* Static initialization of a crc structure */
40#define CRC_INITIALIZER(_order, _polynom, _initial_value, _final_xor) { \
41 .state = ((_initial_value) & ((1L<<(_order))-1)), \
42 .order = (_order), \
43 .polynom = (_polynom), \
44 .initial_value = (_initial_value), \
45 .final_xor = (_final_xor), \
46 .mask = ((1L<<(_order))-1) }
47
48#endif /* __CRC_H */
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