fs/jffs2/Kconfig

   1 config JFFS2_FS
   2         tristate "Journalling Flash File System v2 (JFFS2) support"
   3         select CRC32
   4         depends on MTD
   5         help
   6           JFFS2 is the second generation of the Journalling Flash File System
   7           for use on diskless embedded devices. It provides improved wear
   8           levelling, compression and support for hard links. You cannot use
   9           this on normal block devices, only on 'MTD' devices.
  10
  11           Further information on the design and implementation of JFFS2 is
  12           available at <http://sources.redhat.com/jffs2/>.
  13
  14 config JFFS2_FS_DEBUG
  15         int "JFFS2 debugging verbosity (0 = quiet, 2 = noisy)"
  16         depends on JFFS2_FS
  17         default "0"
  18         help
  19           This controls the amount of debugging messages produced by the JFFS2
  20           code. Set it to zero for use in production systems. For evaluation,
  21           testing and debugging, it's advisable to set it to one. This will
  22           enable a few assertions and will print debugging messages at the
  23           KERN_DEBUG loglevel, where they won't normally be visible. Level 2
  24           is unlikely to be useful - it enables extra debugging in certain
  25           areas which at one point needed debugging, but when the bugs were
  26           located and fixed, the detailed messages were relegated to level 2.
  27
  28           If reporting bugs, please try to have available a full dump of the
  29           messages at debug level 1 while the misbehaviour was occurring.
  30
  31 config JFFS2_FS_WRITEBUFFER
  32         bool "JFFS2 write-buffering support"
  33         depends on JFFS2_FS
  34         default y
  35         help
  36           This enables the write-buffering support in JFFS2.
  37
  38           This functionality is required to support JFFS2 on the following
  39           types of flash devices:
  40             - NAND flash
  41             - NOR flash with transparent ECC
  42             - DataFlash
  43
  44 config JFFS2_FS_WBUF_VERIFY
  45         bool "Verify JFFS2 write-buffer reads"
  46         depends on JFFS2_FS_WRITEBUFFER
  47         default n
  48         help
  49           This causes JFFS2 to read back every page written through the
  50           write-buffer, and check for errors.
  51
  52 config JFFS2_SUMMARY
  53         bool "JFFS2 summary support"
  54         depends on JFFS2_FS
  55         default n
  56         help
  57           This feature makes it possible to use summary information
  58           for faster filesystem mount.
  59
  60           The summary information can be inserted into a filesystem image
  61           by the utility 'sumtool'.
  62
  63           If unsure, say 'N'.
  64
  65 config JFFS2_FS_XATTR
  66         bool "JFFS2 XATTR support"
  67         depends on JFFS2_FS
  68         default n
  69         help
  70           Extended attributes are name:value pairs associated with inodes by
  71           the kernel or by users (see the attr(5) manual page, or visit
  72           <http://acl.bestbits.at/> for details).
  73
  74           If unsure, say N.
  75
  76 config JFFS2_FS_POSIX_ACL
  77         bool "JFFS2 POSIX Access Control Lists"
  78         depends on JFFS2_FS_XATTR
  79         default y
  80         select FS_POSIX_ACL
  81         help
  82           Posix Access Control Lists (ACLs) support permissions for users and
  83           groups beyond the owner/group/world scheme.
  84
  85           To learn more about Access Control Lists, visit the Posix ACLs for
  86           Linux website <http://acl.bestbits.at/>.
  87
  88           If you don't know what Access Control Lists are, say N
  89
  90 config JFFS2_FS_SECURITY
  91         bool "JFFS2 Security Labels"
  92         depends on JFFS2_FS_XATTR
  93         default y
  94         help
  95           Security labels support alternative access control models
  96           implemented by security modules like SELinux.  This option
  97           enables an extended attribute handler for file security
  98           labels in the jffs2 filesystem.
  99
 100           If you are not using a security module that requires using
 101           extended attributes for file security labels, say N.
 102
 103 config JFFS2_COMPRESSION_OPTIONS
 104         bool "Advanced compression options for JFFS2"
 105         depends on JFFS2_FS
 106         default n
 107         help
 108           Enabling this option allows you to explicitly choose which
 109           compression modules, if any, are enabled in JFFS2. Removing
 110           compressors can mean you cannot read existing file systems,
 111           and enabling experimental compressors can mean that you
 112           write a file system which cannot be read by a standard kernel.
 113
 114           If unsure, you should _definitely_ say 'N'.
 115
 116 config JFFS2_ZLIB
 117         bool "JFFS2 ZLIB compression support" if JFFS2_COMPRESSION_OPTIONS
 118         select ZLIB_INFLATE
 119         select ZLIB_DEFLATE
 120         depends on JFFS2_FS
 121         default y
 122         help
 123           Zlib is designed to be a free, general-purpose, legally unencumbered,
 124           lossless data-compression library for use on virtually any computer
 125           hardware and operating system. See <http://www.gzip.org/zlib/> for
 126           further information.
 127
 128           Say 'Y' if unsure.
 129
 130 config JFFS2_LZO
 131         bool "JFFS2 LZO compression support" if JFFS2_COMPRESSION_OPTIONS
 132         select LZO_COMPRESS
 133         select LZO_DECOMPRESS
 134         depends on JFFS2_FS
 135         default n
 136         help
 137           minilzo-based compression. Generally works better than Zlib.
 138
 139           This feature was added in July, 2007. Say 'N' if you need
 140           compatibility with older bootloaders or kernels.
 141
 142 config JFFS2_RTIME
 143         bool "JFFS2 RTIME compression support" if JFFS2_COMPRESSION_OPTIONS
 144         depends on JFFS2_FS
 145         default y
 146         help
 147           Rtime does manage to recompress already-compressed data. Say 'Y' if unsure.
 148
 149 config JFFS2_RUBIN
 150         bool "JFFS2 RUBIN compression support" if JFFS2_COMPRESSION_OPTIONS
 151         depends on JFFS2_FS
 152         default n
 153         help
 154           RUBINMIPS and DYNRUBIN compressors. Say 'N' if unsure.
 155
 156 choice
 157         prompt "JFFS2 default compression mode" if JFFS2_COMPRESSION_OPTIONS
 158         default JFFS2_CMODE_PRIORITY
 159         depends on JFFS2_FS
 160         help
 161           You can set here the default compression mode of JFFS2 from
 162           the available compression modes. Don't touch if unsure.
 163
 164 config JFFS2_CMODE_NONE
 165         bool "no compression"
 166         help
 167           Uses no compression.
 168
 169 config JFFS2_CMODE_PRIORITY
 170         bool "priority"
 171         help
 172           Tries the compressors in a predefined order and chooses the first
 173           successful one.
 174
 175 config JFFS2_CMODE_SIZE
 176         bool "size"
 177         help
 178           Tries all compressors and chooses the one which has the smallest
 179           result.
 180
 181 config JFFS2_CMODE_FAVOURLZO
 182         bool "Favour LZO"
 183         help
 184           Tries all compressors and chooses the one which has the smallest
 185           result but gives some preference to LZO (which has faster
 186           decompression) at the expense of size.
 187
 188 endchoice