[kernel] dissect yaffs patch

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@9249 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 175 insertions, 0 deletions

diff --git a/target/linux/generic-2.6/files/fs/yaffs2/Kconfig b/target/linux/generic-2.6/files/fs/yaffs2/Kconfig
new file mode 100644
index 000000000..f55b3c510
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+++ b/target/linux/generic-2.6/files/fs/yaffs2/Kconfig
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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.