mirror of
https://github.com/zephyrproject-rtos/zephyr
synced 2025-08-13 08:45:24 +00:00
5d8eadd7b1
'pad' parameter controls whether crc16() should add padding at the end of input bytes or not. This allows to compute CRC16 for data stored in non-contiguous buffers where CRC value is calculated using subsequent calls to crc16() with padding added only for last chunk. Signed-off-by: Andrzej Kaczmarek <andrzej.kaczmarek@codecoup.pl>
69 lines
1.6 KiB
C
69 lines
1.6 KiB
C
/*
|
|
* Copyright (c) 2017 Intel Corporation.
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
/** @file
|
|
* @brief CRC 16 computation function
|
|
*/
|
|
|
|
#ifndef __CRC16_H
|
|
#define __CRC16_H
|
|
|
|
#include <zephyr/types.h>
|
|
#include <stdbool.h>
|
|
#include <stddef.h>
|
|
|
|
/**
|
|
* @brief Generic function for computing CRC 16
|
|
*
|
|
* Compute CRC 16 by passing in the address of the input, the input length
|
|
* and polynomial used in addition to the initial value.
|
|
*
|
|
* @param src Input bytes for the computation
|
|
* @param len Length of the input in bytes
|
|
* @param polynomial The polynomial to use omitting the leading x^16
|
|
* coefficient
|
|
* @param initial_value Initial value for the CRC computation
|
|
* @param pad Adds padding with zeros at the end of input bytes
|
|
*
|
|
* @return The computed CRC16 value
|
|
*/
|
|
u16_t crc16(const u8_t *src, size_t len, u16_t polynomial,
|
|
u16_t initial_value, bool pad);
|
|
|
|
/**
|
|
* @brief Compute CCITT variant of CRC 16
|
|
*
|
|
* CCITT variant of CRC 16 is using 0x1021 as its polynomial with the initial
|
|
* value set to 0xffff.
|
|
*
|
|
* @param src Input bytes for the computation
|
|
* @param len Length of the input in bytes
|
|
*
|
|
* @return The computed CRC16 value
|
|
*/
|
|
static inline u16_t crc16_ccitt(const u8_t *src, size_t len)
|
|
{
|
|
return crc16(src, len, 0x1021, 0xffff, true);
|
|
}
|
|
|
|
/**
|
|
* @brief Compute ANSI variant of CRC 16
|
|
*
|
|
* ANSI variant of CRC 16 is using 0x8005 as its polynomial with the initial
|
|
* value set to 0xffff.
|
|
*
|
|
* @param src Input bytes for the computation
|
|
* @param len Length of the input in bytes
|
|
*
|
|
* @return The computed CRC16 value
|
|
*/
|
|
static inline u16_t crc16_ansi(const u8_t *src, size_t len)
|
|
{
|
|
return crc16(src, len, 0x8005, 0xffff, true);
|
|
}
|
|
|
|
#endif
|