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#
# YAFFS file system configurations
#
config YAFFS_FS
tristate "YAFFS2 file system support"
default n
depends on MTD
select YAFFS_YAFFS1
select YAFFS_YAFFS2
help
YAFFS2, or Yet Another Flash Filing System, is a filing system
optimised for NAND Flash chips.
To compile the YAFFS2 file system support as a module, choose M
here: the module will be called yaffs2.
If unsure, say N.
Further information on YAFFS2 is available at
<http://www.aleph1.co.uk/yaffs/>.
config YAFFS_YAFFS1
bool "512 byte / page devices"
depends on YAFFS_FS
default y
help
Enable YAFFS1 support -- yaffs for 512 byte / page devices
Not needed for 2K-page devices.
If unsure, say Y.
config YAFFS_9BYTE_TAGS
bool "Use older-style on-NAND data format with pageStatus byte"
depends on YAFFS_YAFFS1
default n
help
Older-style on-NAND data format has a "pageStatus" byte to record
chunk/page state. This byte is zero when the page is discarded.
Choose this option if you have existing on-NAND data using this
format that you need to continue to support. New data written
also uses the older-style format. Note: Use of this option
generally requires that MTD's oob layout be adjusted to use the
older-style format. See notes on tags formats and MTD versions.
If unsure, say N.
config YAFFS_DOES_ECC
bool "Lets Yaffs do its own ECC"
depends on YAFFS_FS && YAFFS_YAFFS1 && !YAFFS_9BYTE_TAGS
default n
help
This enables Yaffs to use its own ECC functions instead of using
the ones from the generic MTD-NAND driver.
If unsure, say N.
config YAFFS_ECC_WRONG_ORDER
bool "Use the same ecc byte order as Steven Hill's nand_ecc.c"
depends on YAFFS_FS && YAFFS_DOES_ECC && !YAFFS_9BYTE_TAGS
default n
help
This makes yaffs_ecc.c use the same ecc byte order as Steven
Hill's nand_ecc.c. If not set, then you get the same ecc byte
order as SmartMedia.
If unsure, say N.
config YAFFS_YAFFS2
bool "2048 byte (or larger) / page devices"
depends on YAFFS_FS
default y
help
Enable YAFFS2 support -- yaffs for >= 2K bytes per page devices
If unsure, say Y.
config YAFFS_AUTO_YAFFS2
bool "Autoselect yaffs2 format"
depends on YAFFS_YAFFS2
default y
help
Without this, you need to explicitely use yaffs2 as the file
system type. With this, you can say "yaffs" and yaffs or yaffs2
will be used depending on the device page size (yaffs on
512-byte page devices, yaffs2 on 2K page devices).
If unsure, say Y.
config YAFFS_DISABLE_LAZY_LOAD
bool "Disable lazy loading"
depends on YAFFS_YAFFS2
default n
help
"Lazy loading" defers loading file details until they are
required. This saves mount time, but makes the first look-up
a bit longer.
Lazy loading will only happen if enabled by this option being 'n'
and if the appropriate tags are available, else yaffs2 will
automatically fall back to immediate loading and do the right
thing.
Lazy laoding will be required by checkpointing.
Setting this to 'y' will disable lazy loading.
If unsure, say N.
config YAFFS_CHECKPOINT_RESERVED_BLOCKS
int "Reserved blocks for checkpointing"
depends on YAFFS_YAFFS2
default 10
help
Give the number of Blocks to reserve for checkpointing.
Checkpointing saves the state at unmount so that mounting is
much faster as a scan of all the flash to regenerate this state
is not needed. These Blocks are reserved per partition, so if
you have very small partitions the default (10) may be a mess
for you. You can set this value to 0, but that does not mean
checkpointing is disabled at all. There only won't be any
specially reserved blocks for checkpointing, so if there is
enough free space on the filesystem, it will be used for
checkpointing.
If unsure, leave at default (10), but don't wonder if there are
always 2MB used on your large page device partition (10 x 2k
pagesize). When using small partitions or when being very small
on space, you probably want to set this to zero.
config YAFFS_DISABLE_WIDE_TNODES
bool "Turn off wide tnodes"
depends on YAFFS_FS
default n
help
Wide tnodes are only used for NAND arrays >=32MB for 512-byte
page devices and >=128MB for 2k page devices. They use slightly
more RAM but are faster since they eliminate chunk group
searching.
Setting this to 'y' will force tnode width to 16 bits and save
memory but make large arrays slower.
If unsure, say N.
config YAFFS_ALWAYS_CHECK_CHUNK_ERASED
bool "Force chunk erase check"
depends on YAFFS_FS
default n
help
Normally YAFFS only checks chunks before writing until an erased
chunk is found. This helps to detect any partially written
chunks that might have happened due to power loss.
Enabling this forces on the test that chunks are erased in flash
before writing to them. This takes more time but is potentially
a bit more secure.
Suggest setting Y during development and ironing out driver
issues etc. Suggest setting to N if you want faster writing.
If unsure, say Y.
config YAFFS_SHORT_NAMES_IN_RAM
bool "Cache short names in RAM"
depends on YAFFS_FS
default y
help
If this config is set, then short names are stored with the
yaffs_Object. This costs an extra 16 bytes of RAM per object,
but makes look-ups faster.
If unsure, say Y.
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