2 * YAFFS: Yet another Flash File System . A NAND-flash specific file system.
4 * Copyright (C) 2002-2010 Aleph One Ltd.
5 * for Toby Churchill Ltd and Brightstar Engineering
7 * Created by Charles Manning <charles@aleph1.co.uk>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU Lesser General Public License version 2.1 as
11 * published by the Free Software Foundation.
13 * Note: Only YAFFS headers are LGPL, YAFFS C code is covered by GPL.
17 * This code implements the ECC algorithm used in SmartMedia.
19 * The ECC comprises 22 bits of parity information and is stuffed into 3 bytes.
20 * The two unused bit are set to 1.
21 * The ECC can correct single bit errors in a 256-byte page of data. Thus, two such ECC
22 * blocks are used on a 512-byte NAND page.
26 #ifndef __YAFFS_ECC_H__
27 #define __YAFFS_ECC_H__
30 unsigned char colParity;
32 unsigned lineParityPrime;
35 void yaffs_ecc_cacl(const unsigned char *data, unsigned char *ecc);
36 int yaffs_ecc_correct(unsigned char *data, unsigned char *read_ecc,
37 const unsigned char *test_ecc);
39 void yaffs_ecc_calc_other(const unsigned char *data, unsigned n_bytes,
41 int yaffs_ecc_correct_other(unsigned char *data, unsigned n_bytes,
42 yaffs_ECCOther *read_ecc,
43 const yaffs_ECCOther *test_ecc);