2007-10-11 02:05:48 +08:00
|
|
|
/*
|
2008-05-28 15:31:26 +08:00
|
|
|
* YAFFS: Yet another Flash File System . A NAND-flash specific file system.
|
2007-10-11 02:05:48 +08:00
|
|
|
*
|
|
|
|
|
* 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.
|
|
|
|
|
*
|
2008-05-28 15:31:26 +08:00
|
|
|
* The ECC comprises 22 bits of parity information and is stuffed into 3 bytes.
|
2007-10-11 02:05:48 +08:00
|
|
|
* The two unused bit are set to 1.
|
2008-05-28 15:31:26 +08:00
|
|
|
* The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC
|
2007-10-11 02:05:48 +08:00
|
|
|
* 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
|
