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_TAGS_ECC
94 bool "Disable YAFFS from doing ECC on tags by default"
95 depends on YAFFS_FS && YAFFS_YAFFS2
98 This defaults Yaffs to using its own ECC calculations on tags instead of
99 just relying on the MTD.
100 This behavior can also be overridden with tags_ecc_on and
101 tags_ecc_off mount options.
105 config YAFFS_DISABLE_LAZY_LOAD
106 bool "Disable lazy loading"
107 depends on YAFFS_YAFFS2
110 "Lazy loading" defers loading file details until they are
111 required. This saves mount time, but makes the first look-up
114 Lazy loading will only happen if enabled by this option being 'n'
115 and if the appropriate tags are available, else yaffs2 will
116 automatically fall back to immediate loading and do the right
119 Lazy laoding will be required by checkpointing.
121 Setting this to 'y' will disable lazy loading.
126 config YAFFS_DISABLE_WIDE_TNODES
127 bool "Turn off wide tnodes"
131 Wide tnodes are only used for NAND arrays >=32MB for 512-byte
132 page devices and >=128MB for 2k page devices. They use slightly
133 more RAM but are faster since they eliminate chunk group
136 Setting this to 'y' will force tnode width to 16 bits and save
137 memory but make large arrays slower.
141 config YAFFS_ALWAYS_CHECK_CHUNK_ERASED
142 bool "Force chunk erase check"
146 Normally YAFFS only checks chunks before writing until an erased
147 chunk is found. This helps to detect any partially written
148 chunks that might have happened due to power loss.
150 Enabling this forces on the test that chunks are erased in flash
151 before writing to them. This takes more time but is potentially
154 Suggest setting Y during development and ironing out driver
155 issues etc. Suggest setting to N if you want faster writing.
159 config YAFFS_SHORT_NAMES_IN_RAM
160 bool "Cache short names in RAM"
164 If this config is set, then short names are stored with the
165 yaffs_Object. This costs an extra 16 bytes of RAM per object,
166 but makes look-ups faster.