2 # YAFFS file system configurations
6 tristate "YAFFS2 file system support"
12 YAFFS2, or Yet Another Flash Filing System, is a filing system
13 optimised for NAND Flash chips.
15 To compile the YAFFS2 file system support as a module, choose M
16 here: the module will be called yaffs2.
20 Further information on YAFFS2 is available at
21 <http://www.aleph1.co.uk/yaffs/>.
24 bool "512 byte / page devices"
28 Enable YAFFS1 support -- yaffs for 512 byte / page devices
30 Not needed for 2K-page devices.
34 config YAFFS_9BYTE_TAGS
35 bool "Use older-style on-NAND data format with pageStatus byte"
36 depends on YAFFS_YAFFS1
40 Older-style on-NAND data format has a "pageStatus" byte to record
41 chunk/page state. This byte is zero when the page is discarded.
42 Choose this option if you have existing on-NAND data using this
43 format that you need to continue to support. New data written
44 also uses the older-style format. Note: Use of this option
45 generally requires that MTD's oob layout be adjusted to use the
46 older-style format. See notes on tags formats and MTD versions
52 bool "Lets Yaffs do its own ECC"
53 depends on YAFFS_FS && YAFFS_YAFFS1 && !YAFFS_9BYTE_TAGS
56 This enables Yaffs to use its own ECC functions instead of using
57 the ones from the generic MTD-NAND driver.
61 config YAFFS_ECC_WRONG_ORDER
62 bool "Use the same ecc byte order as Steven Hill's nand_ecc.c"
63 depends on YAFFS_FS && YAFFS_DOES_ECC && !YAFFS_9BYTE_TAGS
66 This makes yaffs_ecc.c use the same ecc byte order as Steven
67 Hill's nand_ecc.c. If not set, then you get the same ecc byte
73 bool "2048 byte (or larger) / page devices"
77 Enable YAFFS2 support -- yaffs for >= 2K bytes per page devices
81 config YAFFS_AUTO_YAFFS2
82 bool "Autoselect yaffs2 format"
83 depends on YAFFS_YAFFS2
86 Without this, you need to explicitely use yaffs2 as the file
87 system type. With this, you can say "yaffs" and yaffs or yaffs2
88 will be used depending on the device page size (yaffs on
89 512-byte page devices, yaffs2 on 2K page devices).
93 config YAFFS_DISABLE_LAZY_LOAD
94 bool "Disable lazy loading"
95 depends on YAFFS_YAFFS2
98 "Lazy loading" defers loading file details until they are
99 required. This saves mount time, but makes the first look-up
102 Lazy loading will only happen if enabled by this option being 'n'
103 and if the appropriate tags are available, else yaffs2 will
104 automatically fall back to immediate loading and do the right
107 Lazy laoding will be required by checkpointing.
109 Setting this to 'y' will disable lazy loading.
113 config YAFFS_CHECKPOINT_RESERVED_BLOCKS
114 int "Reserved blocks for checkpointing"
115 depends on YAFFS_YAFFS2
118 Give the number of Blocks to reserve for checkpointing.
119 Checkpointing saves the state at unmount so that mounting is
120 much faster as a scan of all the flash to regenerate this state
121 is not needed. These Blocks are reserved per partition, so if
122 you have very small partitions the default (10) may be a mess
123 for you. You can set this value to 0, but that does not mean
124 checkpointing is disabled at all. There only won't be any
125 specially reserved blocks for checkpointing, so if there is
126 enough free space on the filesystem, it will be used for
129 If unsure, leave at default (10), but don't wonder if there are
130 always 2MB used on your large page device partition (10 x 2k
131 pagesize). When using small partitions or when being very small
132 on space, you probably want to set this to zero.
134 config YAFFS_DISABLE_WIDE_TNODES
135 bool "Turn off wide tnodes"
139 Wide tnodes are only used for NAND arrays >=32MB for 512-byte
140 page devices and >=128MB for 2k page devices. They use slightly
141 more RAM but are faster since they eliminate chunk group
144 Setting this to 'y' will force tnode width to 16 bits and save
145 memory but make large arrays slower.
149 config YAFFS_ALWAYS_CHECK_CHUNK_ERASED
150 bool "Force chunk erase check"
154 Normally YAFFS only checks chunks before writing until an erased
155 chunk is found. This helps to detect any partially written
156 chunks that might have happened due to power loss.
158 Enabling this forces on the test that chunks are erased in flash
159 before writing to them. This takes more time but is potentially
162 Suggest setting Y during development and ironing out driver
163 issues etc. Suggest setting to N if you want faster writing.
167 config YAFFS_SHORT_NAMES_IN_RAM
168 bool "Cache short names in RAM"
172 If this config is set, then short names are stored with the
173 yaffs_Object. This costs an extra 16 bytes of RAM per object,
174 but makes look-ups faster.