/* * YAFFS: Yet another Flash File System . A NAND-flash specific file system. * * Copyright (C) 2002-2007 Aleph One Ltd. * for Toby Churchill Ltd and Brightstar Engineering * * Created by Charles Manning <charles@aleph1.co.uk> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License version 2.1 as * published by the Free Software Foundation. * * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL. */ /* * This code implements the ECC algorithm used in SmartMedia. * * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes. * The two unused bit are set to 1. * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC * blocks are used on a 512-byte NAND page. * */ #ifndef __YAFFS_ECC_H__ #define __YAFFS_ECC_H__ typedef struct { unsigned char colParity; unsigned lineParity; unsigned lineParityPrime; } yaffs_ECCOther; void yaffs_ECCCalculate(const unsigned char *data, unsigned char *ecc); int yaffs_ECCCorrect(unsigned char *data, unsigned char *read_ecc, const unsigned char *test_ecc); void yaffs_ECCCalculateOther(const unsigned char *data, unsigned nBytes, yaffs_ECCOther * ecc); int yaffs_ECCCorrectOther(unsigned char *data, unsigned nBytes, yaffs_ECCOther * read_ecc, const yaffs_ECCOther * test_ecc); #endif