mtdnand.tmpl

linux 内核源代码

<entry>reserved</entry>
</row>
<row>
<entry>0x05</entry>
<entry>Bad block marker</entry>
<entry>If any bit in this byte is zero, then this block is bad.
This applies only to the first page in a block. In the remaining
pages this byte is reserved</entry>
</row>
<row>
<entry>0x06</entry>
<entry>ECC byte 4</entry>
<entry>Error correction code byte 1 of the upper 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x07</entry>
<entry>ECC byte 5</entry>
<entry>Error correction code byte 2 of the upper 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x08 - 0x0F</entry>
<entry>Autoplace 0 - 7</entry>
<entry></entry>
</row>
</tbody></tgroup></informaltable>
		</sect2>
		<sect2>
			<title>2048 byte pagesize</title>
<informaltable><tgroup cols="3"><tbody>
<row>
<entry>Offset</entry>
<entry>Content</entry>
<entry>Comment</entry>
</row>
<row>
<entry>0x00</entry>
<entry>Bad block marker</entry>
<entry>If any bit in this byte is zero, then this block is bad.
This applies only to the first page in a block. In the remaining
pages this byte is reserved</entry>
</row>
<row>
<entry>0x01</entry>
<entry>Reserved</entry>
<entry>Reserved</entry>
</row>
<row>
<entry>0x02-0x27</entry>
<entry>Autoplace 0 - 37</entry>
<entry></entry>
</row>
<row>
<entry>0x28</entry>
<entry>ECC byte 0</entry>
<entry>Error correction code byte 0 of the first 256 Byte data in
this page</entry>
</row>
<row>
<entry>0x29</entry>
<entry>ECC byte 1</entry>
<entry>Error correction code byte 1 of the first 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x2A</entry>
<entry>ECC byte 2</entry>
<entry>Error correction code byte 2 of the first 256 Bytes data in
this page</entry>
</row>
<row>
<entry>0x2B</entry>
<entry>ECC byte 3</entry>
<entry>Error correction code byte 0 of the second 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x2C</entry>
<entry>ECC byte 4</entry>
<entry>Error correction code byte 1 of the second 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x2D</entry>
<entry>ECC byte 5</entry>
<entry>Error correction code byte 2 of the second 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x2E</entry>
<entry>ECC byte 6</entry>
<entry>Error correction code byte 0 of the third 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x2F</entry>
<entry>ECC byte 7</entry>
<entry>Error correction code byte 1 of the third 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x30</entry>
<entry>ECC byte 8</entry>
<entry>Error correction code byte 2 of the third 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x31</entry>
<entry>ECC byte 9</entry>
<entry>Error correction code byte 0 of the fourth 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x32</entry>
<entry>ECC byte 10</entry>
<entry>Error correction code byte 1 of the fourth 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x33</entry>
<entry>ECC byte 11</entry>
<entry>Error correction code byte 2 of the fourth 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x34</entry>
<entry>ECC byte 12</entry>
<entry>Error correction code byte 0 of the fifth 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x35</entry>
<entry>ECC byte 13</entry>
<entry>Error correction code byte 1 of the fifth 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x36</entry>
<entry>ECC byte 14</entry>
<entry>Error correction code byte 2 of the fifth 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x37</entry>
<entry>ECC byte 15</entry>
<entry>Error correction code byte 0 of the sixt 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x38</entry>
<entry>ECC byte 16</entry>
<entry>Error correction code byte 1 of the sixt 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x39</entry>
<entry>ECC byte 17</entry>
<entry>Error correction code byte 2 of the sixt 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x3A</entry>
<entry>ECC byte 18</entry>
<entry>Error correction code byte 0 of the seventh 256 Bytes of
data in this page</entry>
</row>
<row>
<entry>0x3B</entry>
<entry>ECC byte 19</entry>
<entry>Error correction code byte 1 of the seventh 256 Bytes of
data in this page</entry>
</row>
<row>
<entry>0x3C</entry>
<entry>ECC byte 20</entry>
<entry>Error correction code byte 2 of the seventh 256 Bytes of
data in this page</entry>
</row>
<row>
<entry>0x3D</entry>
<entry>ECC byte 21</entry>
<entry>Error correction code byte 0 of the eigth 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x3E</entry>
<entry>ECC byte 22</entry>
<entry>Error correction code byte 1 of the eigth 256 Bytes of data
in this page</entry>
</row>
<row>
<entry>0x3F</entry>
<entry>ECC byte 23</entry>
<entry>Error correction code byte 2 of the eigth 256 Bytes of data
in this page</entry>
</row>
</tbody></tgroup></informaltable>
		</sect2>
     	</sect1>
  </chapter>

  <chapter id="filesystems">
     	<title>Filesystem support</title>
	<para>
		The NAND driver provides all neccecary functions for a
		filesystem via the MTD interface.
	</para>
	<para>
		Filesystems must be aware of the NAND pecularities and
		restrictions. One major restrictions of NAND Flash is, that you cannot 
		write as often as you want to a page. The consecutive writes to a page, 
		before erasing it again, are restricted to 1-3 writes, depending on the 
		manufacturers specifications. This applies similar to the spare area. 
	</para>
	<para>
		Therefor NAND aware filesystems must either write in page size chunks
		or hold a writebuffer to collect smaller writes until they sum up to 
		pagesize. Available NAND aware filesystems: JFFS2, YAFFS. 		
	</para>
	<para>
		The spare area usage to store filesystem data is controlled by
		the spare area placement functionality which is described in one
		of the earlier chapters.
	</para>
  </chapter>	
  <chapter id="tools">
     	<title>Tools</title>
	<para>
		The MTD project provides a couple of helpful tools to handle NAND Flash.
		<itemizedlist>
		<listitem><para>flasherase, flasheraseall: Erase and format FLASH partitions</para></listitem>
		<listitem><para>nandwrite: write filesystem images to NAND FLASH</para></listitem>
		<listitem><para>nanddump: dump the contents of a NAND FLASH partitions</para></listitem>
		</itemizedlist>
	</para>
	<para>
		These tools are aware of the NAND restrictions. Please use those tools
		instead of complaining about errors which are caused by non NAND aware
		access methods.
	</para>
  </chapter>	

  <chapter id="defines">
     <title>Constants</title>
     <para>
     This chapter describes the constants which might be relevant for a driver developer.
     </para>
     <sect1>   
	<title>Chip option constants</title>
     	<sect2>   
		<title>Constants for chip id table</title>
     		<para>
		These constants are defined in nand.h. They are ored together to describe
		the chip functionality.
     		<programlisting>
/* Chip can not auto increment pages */
#define NAND_NO_AUTOINCR	0x00000001
/* Buswitdh is 16 bit */
#define NAND_BUSWIDTH_16	0x00000002
/* Device supports partial programming without padding */
#define NAND_NO_PADDING		0x00000004
/* Chip has cache program function */
#define NAND_CACHEPRG		0x00000008
/* Chip has copy back function */
#define NAND_COPYBACK		0x00000010
/* AND Chip which has 4 banks and a confusing page / block 
 * assignment. See Renesas datasheet for further information */
#define NAND_IS_AND		0x00000020
/* Chip has a array of 4 pages which can be read without
 * additional ready /busy waits */
#define NAND_4PAGE_ARRAY	0x00000040 
		</programlisting>
     		</para>
     	</sect2>
     	<sect2>   
		<title>Constants for runtime options</title>
     		<para>
		These constants are defined in nand.h. They are ored together to describe
		the functionality.
     		<programlisting>
/* Use a flash based bad block table. This option is parsed by the
 * default bad block table function (nand_default_bbt). */
#define NAND_USE_FLASH_BBT	0x00010000
/* The hw ecc generator provides a syndrome instead a ecc value on read 
 * This can only work if we have the ecc bytes directly behind the 
 * data bytes. Applies for DOC and AG-AND Renesas HW Reed Solomon generators */
#define NAND_HWECC_SYNDROME	0x00020000
		</programlisting>
     		</para>
     	</sect2>
     </sect1>	

     <sect1>   
	<title>ECC selection constants</title>
	<para>
	Use these constants to select the ECC algorithm.
  	<programlisting>
/* No ECC. Usage is not recommended ! */
#define NAND_ECC_NONE		0
/* Software ECC 3 byte ECC per 256 Byte data */
#define NAND_ECC_SOFT		1
/* Hardware ECC 3 byte ECC per 256 Byte data */
#define NAND_ECC_HW3_256	2
/* Hardware ECC 3 byte ECC per 512 Byte data */
#define NAND_ECC_HW3_512	3
/* Hardware ECC 6 byte ECC per 512 Byte data */
#define NAND_ECC_HW6_512	4
/* Hardware ECC 6 byte ECC per 512 Byte data */
#define NAND_ECC_HW8_512	6
	</programlisting>
	</para>
     </sect1>	

     <sect1>   
	<title>Hardware control related constants</title>
	<para>
	These constants describe the requested hardware access function when
	the boardspecific hardware control function is called
  	<programlisting>
/* Select the chip by setting nCE to low */
#define NAND_CTL_SETNCE 	1
/* Deselect the chip by setting nCE to high */
#define NAND_CTL_CLRNCE		2
/* Select the command latch by setting CLE to high */
#define NAND_CTL_SETCLE		3
/* Deselect the command latch by setting CLE to low */
#define NAND_CTL_CLRCLE		4
/* Select the address latch by setting ALE to high */
#define NAND_CTL_SETALE		5
/* Deselect the address latch by setting ALE to low */
#define NAND_CTL_CLRALE		6
/* Set write protection by setting WP to high. Not used! */
#define NAND_CTL_SETWP		7
/* Clear write protection by setting WP to low. Not used! */
#define NAND_CTL_CLRWP		8
	</programlisting>
	</para>
     </sect1>	

     <sect1>   
	<title>Bad block table related constants</title>
	<para>
	These constants describe the options used for bad block
	table descriptors.
  	<programlisting>
/* 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 axists */
#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
	</programlisting>
	</para>
     </sect1>	

  </chapter>
  	
  <chapter id="structs">
     <title>Structures</title>
     <para>
     This chapter contains the autogenerated documentation of the structures which are
     used in the NAND driver and might be relevant for a driver developer. Each  
     struct member has a short description which is marked with an [XXX] identifier.
     See the chapter "Documentation hints" for an explanation.
     </para>
!Iinclude/linux/mtd/nand.h
  </chapter>

  <chapter id="pubfunctions">
     <title>Public Functions Provided</title>
     <para>
     This chapter contains the autogenerated documentation of the NAND kernel API functions
      which are exported. Each function has a short description which is marked with an [XXX] identifier.
     See the chapter "Documentation hints" for an explanation.
     </para>
!Edrivers/mtd/nand/nand_base.c
!Edrivers/mtd/nand/nand_bbt.c
!Edrivers/mtd/nand/nand_ecc.c
  </chapter>
  
  <chapter id="intfunctions">
     <title>Internal Functions Provided</title>
     <para>
     This chapter contains the autogenerated documentation of the NAND driver internal functions.
     Each function has a short description which is marked with an [XXX] identifier.
     See the chapter "Documentation hints" for an explanation.
     The functions marked with [DEFAULT] might be relevant for a board driver developer.
     </para>
!Idrivers/mtd/nand/nand_base.c
!Idrivers/mtd/nand/nand_bbt.c
<!-- No internal functions for kernel-doc:
X!Idrivers/mtd/nand/nand_ecc.c
-->
  </chapter>

  <chapter id="credits">
     <title>Credits</title>
	<para>
		The following people have contributed to the NAND driver:
		<orderedlist>
			<listitem><para>Steven J. Hill<email>[e-mail]</email></para></listitem>
			<listitem><para>David Woodhouse<email>[e-mail]</email></para></listitem>
			<listitem><para>Thomas Gleixner<email>[e-mail]</email></para></listitem>
		</orderedlist>
		A lot of users have provided bugfixes, improvements and helping hands for testing.
		Thanks a lot.
	</para>
	<para>
		The following people have contributed to this document:
		<orderedlist>
			<listitem><para>Thomas Gleixner<email>[e-mail]</email></para></listitem>
		</orderedlist>
	</para>
  </chapter>
</book>