/*
- * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
*
- * yaffs_ecc.c: ECC generation/correction algorithms.
- *
- * Copyright (C) 2002 Aleph One Ltd.
+ * 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.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
*/
- /*
- * 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.
- *
- */
+/*
+ * 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.
+ *
+ */
/* Table generated by gen-ecc.c
* Using a table means we do not have to calculate p1..p4 and p1'..p4'
*/
const char *yaffs_ecc_c_version =
- "$Id: yaffs_ecc.c,v 1.6 2005-08-11 02:51:49 charles Exp $";
+ "$Id: yaffs_ecc.c,v 1.9 2007-02-14 01:09:06 wookey Exp $";
#include "yportenv.h"
if ((cDelta | lDelta | lDeltaPrime) == 0)
return 0; /* no error */
- if (lDelta == ~lDeltaPrime && (((cDelta ^ (cDelta >> 1)) & 0x15) == 0x15))
+ if (lDelta == ~lDeltaPrime &&
+ (((cDelta ^ (cDelta >> 1)) & 0x15) == 0x15))
{
/* Single bit (recoverable) error in data */
if (cDelta & 0x02)
bit |= 0x01;
+ if(lDelta >= nBytes)
+ return -1;
+
data[lDelta] ^= (1 << bit);
return 1; /* corrected */