1# 2# YAFFS file system configurations 3# 4 5config YAFFS_FS 6 tristate "YAFFS2 file system support" 7 default n 8 depends on MTD 9 select YAFFS_YAFFS1 10 select YAFFS_YAFFS2 11 help 12 YAFFS2, or Yet Another Flash Filing System, is a filing system 13 optimised for NAND Flash chips. 14 15 To compile the YAFFS2 file system support as a module, choose M 16 here: the module will be called yaffs2. 17 18 If unsure, say N. 19 20 Further information on YAFFS2 is available at 21 <http://www.aleph1.co.uk/yaffs/>. 22 23config YAFFS_YAFFS1 24 bool "512 byte / page devices" 25 depends on YAFFS_FS 26 default y 27 help 28 Enable YAFFS1 support -- yaffs for 512 byte / page devices 29 30 Not needed for 2K-page devices. 31 32 If unsure, say Y. 33 34config YAFFS_9BYTE_TAGS 35 bool "Use older-style on-NAND data format with pageStatus byte" 36 depends on YAFFS_YAFFS1 37 default n 38 help 39 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 47 in yaffs_mtdif1.c. 48 49 If unsure, say N. 50 51config YAFFS_DOES_ECC 52 bool "Lets Yaffs do its own ECC" 53 depends on YAFFS_FS && YAFFS_YAFFS1 && !YAFFS_9BYTE_TAGS 54 default n 55 help 56 This enables Yaffs to use its own ECC functions instead of using 57 the ones from the generic MTD-NAND driver. 58 59 If unsure, say N. 60 61config 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 64 default n 65 help 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 68 order as SmartMedia. 69 70 If unsure, say N. 71 72config YAFFS_YAFFS2 73 bool "2048 byte (or larger) / page devices" 74 depends on YAFFS_FS 75 default y 76 help 77 Enable YAFFS2 support -- yaffs for >= 2K bytes per page devices 78 79 If unsure, say Y. 80 81config YAFFS_AUTO_YAFFS2 82 bool "Autoselect yaffs2 format" 83 depends on YAFFS_YAFFS2 84 default y 85 help 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). 90 91 If unsure, say Y. 92 93config YAFFS_DISABLE_LAZY_LOAD 94 bool "Disable lazy loading" 95 depends on YAFFS_YAFFS2 96 default n 97 help 98 "Lazy loading" defers loading file details until they are 99 required. This saves mount time, but makes the first look-up 100 a bit longer. 101 102 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 105 thing. 106 107 Lazy laoding will be required by checkpointing. 108 109 Setting this to 'y' will disable lazy loading. 110 111 If unsure, say N. 112 113config YAFFS_CHECKPOINT_RESERVED_BLOCKS 114 int "Reserved blocks for checkpointing" 115 depends on YAFFS_YAFFS2 116 default 10 117 help 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 127 checkpointing. 128 129 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. 133 134config YAFFS_DISABLE_WIDE_TNODES 135 bool "Turn off wide tnodes" 136 depends on YAFFS_FS 137 default n 138 help 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 142 searching. 143 144 Setting this to 'y' will force tnode width to 16 bits and save 145 memory but make large arrays slower. 146 147 If unsure, say N. 148 149config YAFFS_ALWAYS_CHECK_CHUNK_ERASED 150 bool "Force chunk erase check" 151 depends on YAFFS_FS 152 default n 153 help 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. 157 158 Enabling this forces on the test that chunks are erased in flash 159 before writing to them. This takes more time but is potentially 160 a bit more secure. 161 162 Suggest setting Y during development and ironing out driver 163 issues etc. Suggest setting to N if you want faster writing. 164 165 If unsure, say Y. 166 167config YAFFS_SHORT_NAMES_IN_RAM 168 bool "Cache short names in RAM" 169 depends on YAFFS_FS 170 default y 171 help 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. 175 176 If unsure, say Y. 177