Actions_3085S4_V2/zephyr/lib/os/crc8_sw.c

/*
 * Copyright (c) 2020 Intel Corporation
 * Copyright (c) 2017 Nordic Semiconductor ASA
 * Copyright (c) 2015 Runtime Inc
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <sys/crc.h>

static const uint8_t crc8_ccitt_small_table[16] = {
	0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15,
	0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d
};

uint8_t crc8_ccitt(uint8_t val, const void *buf, size_t cnt)
{
	size_t i;
	const uint8_t *p = buf;

	for (i = 0; i < cnt; i++) {
		val ^= p[i];
		val = (val << 4) ^ crc8_ccitt_small_table[val >> 4];
		val = (val << 4) ^ crc8_ccitt_small_table[val >> 4];
	}
	return val;
}

uint8_t crc8(const uint8_t *src, size_t len, uint8_t polynomial, uint8_t initial_value,
	  bool reversed)
{
	uint8_t crc = initial_value;
	size_t i, j;

	for (i = 0; i < len; i++) {
		crc ^= src[i];

		for (j = 0; j < 8; j++) {
			if (reversed) {
				if (crc & 0x01) {
					crc = (crc >> 1) ^ polynomial;
				} else {
					crc >>= 1;
				}
			} else {
				if (crc & 0x80) {
					crc = (crc << 1) ^ polynomial;
				} else {
					crc <<= 1;
				}
			}
		}
	}

	return crc;
}



//crc8_maxim MSB first talbe
const unsigned char CRC8Table[]=
{
    0x00,0x31,0x62,0x53,0xc4,0xf5,0xa6,0x97,0xb9,0x88,0xdb,0xea,0x7d,0x4c,0x1f,0x2e,
    0x43,0x72,0x21,0x10,0x87,0xb6,0xe5,0xd4,0xfa,0xcb,0x98,0xa9,0x3e,0x0f,0x5c,0x6d,
    0x86,0xb7,0xe4,0xd5,0x42,0x73,0x20,0x11,0x3f,0x0e,0x5d,0x6c,0xfb,0xca,0x99,0xa8,
    0xc5,0xf4,0xa7,0x96,0x01,0x30,0x63,0x52,0x7c,0x4d,0x1e,0x2f,0xb8,0x89,0xda,0xeb,
    0x3d,0x0c,0x5f,0x6e,0xf9,0xc8,0x9b,0xaa,0x84,0xb5,0xe6,0xd7,0x40,0x71,0x22,0x13,
    0x7e,0x4f,0x1c,0x2d,0xba,0x8b,0xd8,0xe9,0xc7,0xf6,0xa5,0x94,0x03,0x32,0x61,0x50,
    0xbb,0x8a,0xd9,0xe8,0x7f,0x4e,0x1d,0x2c,0x02,0x33,0x60,0x51,0xc6,0xf7,0xa4,0x95,
    0xf8,0xc9,0x9a,0xab,0x3c,0x0d,0x5e,0x6f,0x41,0x70,0x23,0x12,0x85,0xb4,0xe7,0xd6,
    0x7a,0x4b,0x18,0x29,0xbe,0x8f,0xdc,0xed,0xc3,0xf2,0xa1,0x90,0x07,0x36,0x65,0x54,
    0x39,0x08,0x5b,0x6a,0xfd,0xcc,0x9f,0xae,0x80,0xb1,0xe2,0xd3,0x44,0x75,0x26,0x17,
    0xfc,0xcd,0x9e,0xaf,0x38,0x09,0x5a,0x6b,0x45,0x74,0x27,0x16,0x81,0xb0,0xe3,0xd2,
    0xbf,0x8e,0xdd,0xec,0x7b,0x4a,0x19,0x28,0x06,0x37,0x64,0x55,0xc2,0xf3,0xa0,0x91,
    0x47,0x76,0x25,0x14,0x83,0xb2,0xe1,0xd0,0xfe,0xcf,0x9c,0xad,0x3a,0x0b,0x58,0x69,
    0x04,0x35,0x66,0x57,0xc0,0xf1,0xa2,0x93,0xbd,0x8c,0xdf,0xee,0x79,0x48,0x1b,0x2a,
    0xc1,0xf0,0xa3,0x92,0x05,0x34,0x67,0x56,0x78,0x49,0x1a,0x2b,0xbc,0x8d,0xde,0xef,
    0x82,0xb3,0xe0,0xd1,0x46,0x77,0x24,0x15,0x3b,0x0a,0x59,0x68,0xff,0xce,0x9d,0xac
};



unsigned char crc8_maxim(unsigned char seed, unsigned char *p, unsigned int counter)
{
    unsigned char crc8 = seed;

    for( ; counter > 0; counter--)
    {
        crc8 = CRC8Table[crc8^*p];
        p++;
    }

    return(crc8);
}