<listitem><para>
[MTD Interface]</para><para>
These functions provide the interface to the MTD kernel API.
- They are not replacable and provide functionality
+ They are not replaceable and provide functionality
which is complete hardware independent.
</para></listitem>
<listitem><para>
</para></listitem>
<listitem><para>
[GENERIC]</para><para>
- Generic functions are not replacable and provide functionality
+ Generic functions are not replaceable and provide functionality
which is complete hardware independent.
</para></listitem>
<listitem><para>
[DEFAULT]</para><para>
Default functions provide hardware related functionality which is suitable
for most of the implementations. These functions can be replaced by the
- board driver if neccecary. Those functions are called via pointers in the
+ board driver if necessary. Those functions are called via pointers in the
NAND chip description structure. The board driver can set the functions which
should be replaced by board dependent functions before calling nand_scan().
If the function pointer is NULL on entry to nand_scan() then the pointer
is set up nand_scan() is called. This function tries to
detect and identify then chip. If a chip is found all the
internal data fields are initialized accordingly.
- The structure(s) have to be zeroed out first and then filled with the neccecary
+ The structure(s) have to be zeroed out first and then filled with the necessary
information about the device.
</para>
<programlisting>
<sect1 id="Exit_function">
<title>Exit function</title>
<para>
- The exit function is only neccecary if the driver is
+ The exit function is only necessary if the driver is
compiled as a module. It releases all resources which
are held by the chip driver and unregisters the partitions
in the MTD layer.
in this case. See rts_from4.c and diskonchip.c for
implementation reference. In those cases we must also
use bad block tables on FLASH, because the ECC layout is
- interferring with the bad block marker positions.
+ interfering with the bad block marker positions.
See bad block table support for details.
</para>
</sect2>
<para>
nand_scan() calls the function nand_default_bbt().
nand_default_bbt() selects appropriate default
- bad block table desriptors depending on the chip information
+ bad block table descriptors depending on the chip information
which was retrieved by nand_scan().
</para>
<para>
<sect2 id="Flash_based_tables">
<title>Flash based tables</title>
<para>
- It may be desired or neccecary to keep a bad block table in FLASH.
+ It may be desired or necessary to keep a bad block table in FLASH.
For AG-AND chips this is mandatory, as they have no factory marked
bad blocks. They have factory marked good blocks. The marker pattern
is erased when the block is erased to be reused. So in case of
of the blocks.
</para>
<para>
- The blocks in which the tables are stored are procteted against
+ The blocks in which the tables are stored are protected against
accidental access by marking them bad in the memory bad block
table. The bad block table management functions are allowed
- to circumvernt this protection.
+ to circumvent this protection.
</para>
<para>
The simplest way to activate the FLASH based bad block table support
User defined tables are created by filling out a
nand_bbt_descr structure and storing the pointer in the
nand_chip structure member bbt_td before calling nand_scan().
- If a mirror table is neccecary a second structure must be
+ If a mirror table is necessary a second structure must be
created and a pointer to this structure must be stored
in bbt_md inside the nand_chip structure. If the bbt_md
member is set to NULL then only the main table is used
<para>
For automatic placement some blocks must be reserved for
bad block table storage. The number of reserved blocks is defined
- in the maxblocks member of the babd block table description structure.
+ in the maxblocks member of the bad block table description structure.
Reserving 4 blocks for mirrored tables should be a reasonable number.
This also limits the number of blocks which are scanned for the bad
block table ident pattern.
<chapter id="filesystems">
<title>Filesystem support</title>
<para>
- The NAND driver provides all neccecary functions for a
+ The NAND driver provides all necessary functions for a
filesystem via the MTD interface.
</para>
<para>
- Filesystems must be aware of the NAND pecularities and
+ Filesystems must be aware of the NAND peculiarities 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
#define NAND_BBT_VERSION 0x00000100
/* Create a bbt if none axists */
#define NAND_BBT_CREATE 0x00000200
-/* Write bbt if neccecary */
+/* Write bbt if necessary */
#define NAND_BBT_WRITE 0x00001000
/* Read and write back block contents when writing bbt */
#define NAND_BBT_SAVECONTENT 0x00002000