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authorStefan Roese <sr@denx.de>2008-08-13 06:47:12 +0200
committerStefan Roese <sr@denx.de>2008-08-13 06:47:12 +0200
commit5a7ddf4e1fb9347f783eb1473c30187d7a22bd81 (patch)
tree5e30fc06d7bbd5b382b1a7b89f57cd81a5246f32 /fs/yaffs2/yaffs_ecc.h
parent9939ffd5fbf1f5aff4d8172531d4fc33797c62c8 (diff)
parent8641ff266ae6638da201747c239fd39ba34c4958 (diff)
Merge branch 'master' of /home/stefan/git/u-boot/u-boot
Diffstat (limited to 'fs/yaffs2/yaffs_ecc.h')
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1 files changed, 44 insertions, 0 deletions
diff --git a/fs/yaffs2/yaffs_ecc.h b/fs/yaffs2/yaffs_ecc.h
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+/*
+ * 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