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* linux/include/linux/mtd/bbm.h
* NAND family Bad Block Management (BBM) header file
* - Bad Block Table (BBT) implementation
* Copyright (c) 2005-2007 Samsung Electronics
* Kyungmin Park <>
* Copyright (c) 2000-2005
* Thomas Gleixner <>
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#ifndef __LINUX_MTD_BBM_H
#define __LINUX_MTD_BBM_H
/* The maximum number of NAND chips in an array */
* struct nand_bbt_descr - bad block table descriptor
* @param options options for this descriptor
* @param pages the page(s) where we find the bbt, used with
* option BBT_ABSPAGE when bbt is searched,
* then we store the found bbts pages here.
* Its an array and supports up to 8 chips now
* @param offs offset of the pattern in the oob area of the page
* @param veroffs offset of the bbt version counter in the oob are of the page
* @param version version read from the bbt page during scan
* @param len length of the pattern, if 0 no pattern check is performed
* @param maxblocks maximum number of blocks to search for a bbt. This number of
* blocks is reserved at the end of the device
* where the tables are written.
* @param reserved_block_code if non-0, this pattern denotes a reserved
* (rather than bad) block in the stored bbt
* @param pattern pattern to identify bad block table or factory marked
* good / bad blocks, can be NULL, if len = 0
* Descriptor for the bad block table marker and the descriptor for the
* pattern which identifies good and bad blocks. The assumption is made
* that the pattern and the version count are always located in the oob area
* of the first block.
struct nand_bbt_descr {
int options;
int offs;
int veroffs;
uint8_t version[CONFIG_SYS_NAND_MAX_CHIPS];
int len;
int maxblocks;
int reserved_block_code;
uint8_t *pattern;
/* Options for the bad block table descriptors */
/* The number of bits used per block in the bbt on the device */
#define NAND_BBT_NRBITS_MSK 0x0000000F
#define NAND_BBT_1BIT 0x00000001
#define NAND_BBT_2BIT 0x00000002
#define NAND_BBT_4BIT 0x00000004
#define NAND_BBT_8BIT 0x00000008
/* The bad block table is in the last good block of the device */
#define NAND_BBT_LASTBLOCK 0x00000010
/* The bbt is at the given page, else we must scan for the bbt */
#define NAND_BBT_ABSPAGE 0x00000020
/* The bbt is at the given page, else we must scan for the bbt */
#define NAND_BBT_SEARCH 0x00000040
/* bbt is stored per chip on multichip devices */
#define NAND_BBT_PERCHIP 0x00000080
/* bbt has a version counter at offset veroffs */
#define NAND_BBT_VERSION 0x00000100
/* Create a bbt if none exists */
#define NAND_BBT_CREATE 0x00000200
/* Search good / bad pattern through all pages of a block */
#define NAND_BBT_SCANALLPAGES 0x00000400
/* Scan block empty during good / bad block scan */
#define NAND_BBT_SCANEMPTY 0x00000800
/* Write bbt if neccecary */
#define NAND_BBT_WRITE 0x00001000
/* Read and write back block contents when writing bbt */
#define NAND_BBT_SAVECONTENT 0x00002000
/* Search good / bad pattern on the first and the second page */
#define NAND_BBT_SCAN2NDPAGE 0x00004000
/* Search good / bad pattern on the last page of the eraseblock */
#define NAND_BBT_SCANLASTPAGE 0x00008000
/* Chip stores bad block marker on BOTH 1st and 6th bytes of OOB */
#define NAND_BBT_SCANBYTE1AND6 0x00100000
/* The nand_bbt_descr was created dynamicaly and must be freed */
#define NAND_BBT_DYNAMICSTRUCT 0x00200000
/* The bad block table does not OOB for marker */
#define NAND_BBT_NO_OOB 0x00400000
/* The maximum number of blocks to scan for a bbt */
* Constants for oob configuration
* Bad block scanning errors
* struct bbt_info - [GENERIC] Bad Block Table data structure
* @param bbt_erase_shift [INTERN] number of address bits in a bbt entry
* @param badblockpos [INTERN] position of the bad block marker in the oob area
* @param bbt [INTERN] bad block table pointer
* @param badblock_pattern [REPLACEABLE] bad block scan pattern used for initial bad block scan
* @param priv [OPTIONAL] pointer to private bbm date
struct bbm_info {
int bbt_erase_shift;
int badblockpos;
int options;
uint8_t *bbt;
int (*isbad_bbt) (struct mtd_info * mtd, loff_t ofs, int allowbbt);
/* TODO Add more NAND specific fileds */
struct nand_bbt_descr *badblock_pattern;
void *priv;
/* OneNAND BBT interface */
extern int onenand_scan_bbt (struct mtd_info *mtd, struct nand_bbt_descr *bd);
extern int onenand_default_bbt (struct mtd_info *mtd);
#endif /* __LINUX_MTD_BBM_H */