#ifndef __CRC_H
#define __CRC_H
-#include <stdint.h>
+#include <stdint.h> //uint32+
+#include <stdbool.h> //bool
#include <stddef.h>
+#include "util.h" // reflect, bswap_16
typedef struct crc {
uint32_t state;
uint32_t initial_value;
uint32_t final_xor;
uint32_t mask;
+ int topbit;
+ bool refin; /* Parameter: Reflect input bytes? */
+ bool refout; /* Parameter: Reflect output CRC? */
} crc_t;
+/* Initialize a crc structure. order is the order of the polynom, e.g. 32 for a CRC-32
+ * polynom is the CRC polynom. initial_value is the initial value of a clean state.
+ * final_xor is XORed onto the state before returning it from crc_result().
+ * refin is the setting for reversing (bitwise) the bytes during crc
+ * refot is the setting for reversing (bitwise) the crc byte before returning it.
+ */
+extern void crc_init_ref(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor, bool refin, bool refout);
+
/* Initialize a crc structure. order is the order of the polynom, e.g. 32 for a CRC-32
* polynom is the CRC polynom. initial_value is the initial value of a clean state.
* final_xor is XORed onto the state before returning it from crc_result(). */
extern void crc_init(crc_t *crc, int order, uint32_t polynom, uint32_t initial_value, uint32_t final_xor);
+
/* Update the crc state. data is the data of length data_width bits (only the
* data_width lower-most bits are used).
*/
// Calculate CRC-8/Maxim checksum
uint32_t CRC8Maxim(uint8_t *buff, size_t size);
+// Calculate CRC-4/Legic checksum
+uint32_t CRC4Legic(uint8_t *buff, size_t size);
+
// Calculate CRC-8/Legic checksum
uint32_t CRC8Legic(uint8_t *buff, size_t size);
+// Calculate CRC-16/Legic checksum
+// the initial_value is based on the previous legic_Crc8 of the UID.
+// ie: uidcrc = 0x78 then initial_value == 0x7878
+uint32_t CRC16Legic(uint8_t *buff, size_t size, uint8_t uidcrc);
+
+// test crc 16.
+uint32_t CRC16_DNP(uint8_t *buff, size_t size);
+uint32_t CRC16_CCITT(uint8_t *buff, size_t size);
+
/* Static initialization of a crc structure */
#define CRC_INITIALIZER(_order, _polynom, _initial_value, _final_xor) { \
.state = ((_initial_value) & ((1L<<(_order))-1)), \
.polynom = (_polynom), \
.initial_value = (_initial_value), \
.final_xor = (_final_xor), \
- .mask = ((1L<<(_order))-1) }
+ .mask = ((1L<<(_order))-1) \
+ .refin = FALSE, \
+ .refout = FALSE \
+ }
#endif /* __CRC_H */