nand_crc.c revision 1.1.2.2
1 1.1.2.2 bouyer /* $NetBSD: nand_crc.c,v 1.1.2.2 2011/03/05 15:10:22 bouyer Exp $ */ 2 1.1.2.2 bouyer 3 1.1.2.2 bouyer /*- 4 1.1.2.2 bouyer * Copyright (c) 2010 Department of Software Engineering, 5 1.1.2.2 bouyer * University of Szeged, Hungary 6 1.1.2.2 bouyer * Copyright (c) 2010 Adam Hoka <ahoka (at) NetBSD.org> 7 1.1.2.2 bouyer * All rights reserved. 8 1.1.2.2 bouyer * 9 1.1.2.2 bouyer * This code is derived from software contributed to The NetBSD Foundation 10 1.1.2.2 bouyer * by the Department of Software Engineering, University of Szeged, Hungary 11 1.1.2.2 bouyer * 12 1.1.2.2 bouyer * Redistribution and use in source and binary forms, with or without 13 1.1.2.2 bouyer * modification, are permitted provided that the following conditions 14 1.1.2.2 bouyer * are met: 15 1.1.2.2 bouyer * 1. Redistributions of source code must retain the above copyright 16 1.1.2.2 bouyer * notice, this list of conditions and the following disclaimer. 17 1.1.2.2 bouyer * 2. Redistributions in binary form must reproduce the above copyright 18 1.1.2.2 bouyer * notice, this list of conditions and the following disclaimer in the 19 1.1.2.2 bouyer * documentation and/or other materials provided with the distribution. 20 1.1.2.2 bouyer * 21 1.1.2.2 bouyer * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 1.1.2.2 bouyer * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 1.1.2.2 bouyer * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 1.1.2.2 bouyer * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 1.1.2.2 bouyer * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 26 1.1.2.2 bouyer * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 27 1.1.2.2 bouyer * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28 1.1.2.2 bouyer * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29 1.1.2.2 bouyer * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 1.1.2.2 bouyer * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 1.1.2.2 bouyer * SUCH DAMAGE. 32 1.1.2.2 bouyer */ 33 1.1.2.2 bouyer 34 1.1.2.2 bouyer /* Implements CRC-16 as required by the ONFI 2.3 specification */ 35 1.1.2.2 bouyer 36 1.1.2.2 bouyer #include <sys/cdefs.h> 37 1.1.2.2 bouyer __KERNEL_RCSID(0, "$NetBSD: nand_crc.c,v 1.1.2.2 2011/03/05 15:10:22 bouyer Exp $"); 38 1.1.2.2 bouyer 39 1.1.2.2 bouyer #include "nand_crc.h" 40 1.1.2.2 bouyer 41 1.1.2.2 bouyer uint16_t 42 1.1.2.2 bouyer nand_crc16(uint8_t *data, size_t len) 43 1.1.2.2 bouyer { 44 1.1.2.2 bouyer const uint16_t init = 0x4f4e; 45 1.1.2.2 bouyer const uint16_t polynom = 0x8005; 46 1.1.2.2 bouyer const uint16_t highbit = 0x0001 << 15; 47 1.1.2.2 bouyer uint16_t crc = init; 48 1.1.2.2 bouyer size_t i; 49 1.1.2.2 bouyer int j; 50 1.1.2.2 bouyer 51 1.1.2.2 bouyer for (i = 0; i < len; i++) { 52 1.1.2.2 bouyer crc ^= data[i] << 8; 53 1.1.2.2 bouyer 54 1.1.2.2 bouyer for (j = 0; j < 8; j++) { 55 1.1.2.2 bouyer if ((crc & highbit) != 0x00) 56 1.1.2.2 bouyer crc = (crc << 1) ^ polynom; 57 1.1.2.2 bouyer else 58 1.1.2.2 bouyer crc <<= 1; 59 1.1.2.2 bouyer } 60 1.1.2.2 bouyer } 61 1.1.2.2 bouyer 62 1.1.2.2 bouyer return crc; 63 1.1.2.2 bouyer } 64
Indexes created Mon Sep 22 21:09:42 GMT 2025