include/rtems/crc.h

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup RTEMSImplCRC
0007  *
0008  * @brief This header file provides the interfaces of the
0009  *   @ref RTEMSImplCRC.
0010  */
0011
0012 /*
0013  * Copyright (C) 2024 embedded brains GmbH & Co. KG
0014  *
0015  * Redistribution and use in source and binary forms, with or without
0016  * modification, are permitted provided that the following conditions
0017  * are met:
0018  * 1. Redistributions of source code must retain the above copyright
0019  *    notice, this list of conditions and the following disclaimer.
0020  * 2. Redistributions in binary form must reproduce the above copyright
0021  *    notice, this list of conditions and the following disclaimer in the
0022  *    documentation and/or other materials provided with the distribution.
0023  *
0024  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0025  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0026  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0027  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0028  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0029  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0030  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0031  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0032  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0033  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0034  * POSSIBILITY OF SUCH DAMAGE.
0035  */
0036
0037 #ifndef _RTEMS_CRC_H
0038 #define _RTEMS_CRC_H
0039
0040 #include <stddef.h>
0041 #include <stdint.h>
0042
0043 #ifdef __cplusplus
0044 extern "C" {
0045 #endif /* __cplusplus */
0046
0047 /**
0048  * @defgroup RTEMSImplCRC Cyclic Redundancy Check (CRC) Support
0049  *
0050  * @ingroup RTEMSImpl
0051  *
0052  * @brief This group contains functions to calculate
0053  *   Cyclic Redundancy Check (CRC) values.
0054  *
0055  * @{
0056  */
0057
0058
0059 /**
0060  * @brief This constant represents the default CRC-24Q seed state.
0061  */
0062 #define CRC24Q_SEED 0U
0063
0064 /**
0065  * @brief This constant provides a mask to get a valid CRC-24Q value from the
0066  *   integers returned by _CRC24Q_Update() and _CRC24Q_Sequence_update().
0067  */
0068 #define CRC24Q_MASK 0xffffffU
0069
0070 /**
0071  * @brief Updates the CRC-24Q state using a byte.
0072  *
0073  * @param crc is the input CRC-24Q state.
0074  *
0075  * @param byte is the byte updating the input CRC-24Q state.
0076  *
0077  * @return Returns the updated CRC-24Q state.  Use the #CRC24Q_MASK to get a
0078  *   valid CRC-24Q value.
0079  */
0080 uint32_t _CRC24Q_Update( uint32_t crc, uint8_t byte );
0081
0082 /**
0083  * @brief Updates the CRC-24Q state using a sequence of bytes.
0084  *
0085  * @param crc is the input CRC-24Q state.
0086  *
0087  * @param bytes[in] is the sequence of bytes updating the input CRC-24Q state.
0088  *
0089  * @param size_in_bytes is the size in bytes of the byte sequence.
0090  *
0091  * @return Returns the updated CRC-24Q state.  Use the #CRC24Q_MASK to get a
0092  *   valid CRC-24Q value.
0093  */
0094 uint32_t _CRC24Q_Sequence_update(
0095   uint32_t    crc,
0096   const void *bytes,
0097   size_t      size_in_bytes
0098 );
0099
0100 /** @} */
0101
0102 #ifdef __cplusplus
0103 }
0104 #endif /* __cplusplus */
0105
0106 #endif /* _RTEMS_CRC_H */