116 lines
3.6 KiB
C
116 lines
3.6 KiB
C
/**
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* \file
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* <!--
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* This file is part of BeRTOS.
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*
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* Bertos is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* As a special exception, you may use this file as part of a free software
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* library without restriction. Specifically, if other files instantiate
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* templates or use macros or inline functions from this file, or you compile
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* this file and link it with other files to produce an executable, this
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* file does not by itself cause the resulting executable to be covered by
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* the GNU General Public License. This exception does not however
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* invalidate any other reasons why the executable file might be covered by
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* the GNU General Public License.
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*
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* Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
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* Copyright 1999 Bernie Innocenti <bernie@codewiz.org>
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*
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* -->
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*
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* \brief Cyclic Redundancy Check 16 (CRC). This algorithm is the one used by the XMODEM protocol.
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*
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* \note This algorithm is incompatible with the CCITT-CRC16.
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*
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* This code is based on the article Copyright 1986 Stephen Satchell.
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*
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* Programmers may incorporate any or all code into their programs,
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* giving proper credit within the source. Publication of the
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* source routines is permitted so long as proper credit is given
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* to Stephen Satchell, Satchell Evaluations and Chuck Forsberg,
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* Omen Technology.
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*
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* \author Bernie Innocenti <bernie@codewiz.org>
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*
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* $WIZ$ module_name = "crc16"
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*/
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#ifndef ALGO_CRC_H
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#define ALGO_CRC_H
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#include "cfg/cfg_arch.h"
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#include <cfg/compiler.h>
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#include <cpu/pgm.h>
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EXTERN_C_BEGIN
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/* CRC table */
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extern const uint16_t crc16tab[256];
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/**
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* \brief Compute the updated CRC16 value for one octet (macro version)
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*
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* \note This version is only intended for old/broken compilers.
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* Use the inline function in new code.
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*
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* \param c New octet (range 0-255)
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* \param oldcrc Previous CRC16 value (referenced twice, beware of side effects)
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*/
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#if CPU_HARVARD && !(defined(ARCH_BOOT) && (ARCH & ARCH_BOOT))
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#define UPDCRC16(c, oldcrc) (pgm_read_uint16_t(&crc16tab[((oldcrc) >> 8) ^ ((unsigned char)(c))]) ^ ((oldcrc) << 8))
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#else
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#define UPDCRC16(c, oldcrc) ((crc16tab[((oldcrc) >> 8) ^ ((unsigned char)(c))]) ^ ((oldcrc) << 8))
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#endif
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/** CRC-16 init value */
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#define CRC16_INIT_VAL ((uint16_t)0)
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#ifdef INLINE
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/**
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* \brief Compute the updated CRC16 value for one octet (inline version)
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*/
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INLINE uint16_t updcrc16(uint8_t c, uint16_t oldcrc)
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{
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#if CPU_HARVARD && !(defined(ARCH_BOOT) && (ARCH & ARCH_BOOT))
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return pgm_read_uint16_t(&crc16tab[(oldcrc >> 8) ^ c]) ^ (oldcrc << 8);
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#else
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return crc16tab[(oldcrc >> 8) ^ c] ^ (oldcrc << 8);
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#endif
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}
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#endif // INLINE
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/**
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* This function implements the CRC 16 calculation on a buffer.
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*
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* \param crc Current CRC16 value.
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* \param buf The buffer to perform CRC calculation on.
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* \param len The length of the Buffer.
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*
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* \return The updated CRC16 value.
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*/
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extern uint16_t crc16(uint16_t crc, const void *buf, size_t len);
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int crc_testSetup(void);
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int crc_testRun(void);
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int crc_testTearDown(void);
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EXTERN_C_END
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#endif /* ALGO_CRC_H */
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