Working

bertos/algo/crc.h

@@ -0,0 +1,115 @@
+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2003, 2004 Develer S.r.l. (http://www.develer.com/)
+ * Copyright 1999 Bernie Innocenti <bernie@codewiz.org>
+ *
+ * -->
+ *
+ * \brief Cyclic Redundancy Check 16 (CRC). This algorithm is the one used by the XMODEM protocol.
+ *
+ * \note This algorithm is incompatible with the CCITT-CRC16.
+ *
+ * This code is based on the article Copyright 1986 Stephen Satchell.
+ *
+ * Programmers may incorporate any or all code into their programs,
+ * giving proper credit within the source. Publication of the
+ * source routines is permitted so long as proper credit is given
+ * to Stephen Satchell, Satchell Evaluations and Chuck Forsberg,
+ * Omen Technology.
+ *
+ * \author Bernie Innocenti <bernie@codewiz.org>
+ *
+ * $WIZ$ module_name = "crc16"
+ */
+
+#ifndef ALGO_CRC_H
+#define ALGO_CRC_H
+
+#include "cfg/cfg_arch.h"
+
+#include <cfg/compiler.h>
+#include <cpu/pgm.h>
+
+EXTERN_C_BEGIN
+
+/* CRC table */
+extern const uint16_t crc16tab[256];
+
+
+/**
+ * \brief Compute the updated CRC16 value for one octet (macro version)
+ *
+ * \note This version is only intended for old/broken compilers.
+ *       Use the inline function in new code.
+ *
+ * \param c New octet (range 0-255)
+ * \param oldcrc Previous CRC16 value (referenced twice, beware of side effects)
+ */
+#if CPU_HARVARD && !(defined(ARCH_BOOT) && (ARCH & ARCH_BOOT))
+	#define UPDCRC16(c, oldcrc) (pgm_read_uint16_t(&crc16tab[((oldcrc) >> 8) ^ ((unsigned char)(c))]) ^ ((oldcrc) << 8))
+#else
+	#define UPDCRC16(c, oldcrc) ((crc16tab[((oldcrc) >> 8) ^ ((unsigned char)(c))]) ^ ((oldcrc) << 8))
+#endif
+
+/** CRC-16 init value */
+#define CRC16_INIT_VAL ((uint16_t)0)
+
+#ifdef INLINE
+/**
+ * \brief Compute the updated CRC16 value for one octet (inline version)
+ */
+INLINE uint16_t updcrc16(uint8_t c, uint16_t oldcrc)
+{
+#if CPU_HARVARD && !(defined(ARCH_BOOT) && (ARCH & ARCH_BOOT))
+	return pgm_read_uint16_t(&crc16tab[(oldcrc >> 8) ^ c]) ^ (oldcrc << 8);
+#else
+	return crc16tab[(oldcrc >> 8) ^ c] ^ (oldcrc << 8);
+#endif
+}
+#endif // INLINE
+
+
+/**
+ * This function implements the CRC 16 calculation on a buffer.
+ *
+ * \param crc  Current CRC16 value.
+ * \param buf  The buffer to perform CRC calculation on.
+ * \param len  The length of the Buffer.
+ *
+ * \return The updated CRC16 value.
+ */
+extern uint16_t crc16(uint16_t crc, const void *buf, size_t len);
+
+int crc_testSetup(void);
+int crc_testRun(void);
+int crc_testTearDown(void);
+
+EXTERN_C_END
+
+#endif /* ALGO_CRC_H */