64 lines
2.2 KiB
C
64 lines
2.2 KiB
C
/* $NetBSD: nand_crc.c,v 1.1 2011/02/26 18:07:31 ahoka Exp $ */
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/*-
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* Copyright (c) 2010 Department of Software Engineering,
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* University of Szeged, Hungary
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* Copyright (c) 2010 Adam Hoka <ahoka@NetBSD.org>
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by the Department of Software Engineering, University of Szeged, Hungary
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/* Implements CRC-16 as required by the ONFI 2.3 specification */
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: nand_crc.c,v 1.1 2011/02/26 18:07:31 ahoka Exp $");
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#include "nand_crc.h"
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uint16_t
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nand_crc16(uint8_t *data, size_t len)
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{
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const uint16_t init = 0x4f4e;
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const uint16_t polynom = 0x8005;
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const uint16_t highbit = 0x0001 << 15;
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uint16_t crc = init;
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size_t i;
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int j;
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for (i = 0; i < len; i++) {
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crc ^= data[i] << 8;
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for (j = 0; j < 8; j++) {
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if ((crc & highbit) != 0x00)
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crc = (crc << 1) ^ polynom;
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else
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crc <<= 1;
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}
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}
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return crc;
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}
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