fs/jffs2/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 config JFFS2_FS
   3         tristate "Journalling Flash File System v2 (JFFS2) support"
   4         select CRC32
   5         depends on MTD
   6         help
   7           JFFS2 is the second generation of the Journalling Flash File System
   8           for use on diskless embedded devices. It provides improved wear
   9           levelling, compression and support for hard links. You cannot use
  10           this on normal block devices, only on 'MTD' devices.
  11
  12           Further information on the design and implementation of JFFS2 is
  13           available at <http://sources.redhat.com/jffs2/>.
  14
  15 config JFFS2_FS_DEBUG
  16         int "JFFS2 debugging verbosity (0 = quiet, 2 = noisy)"
  17         depends on JFFS2_FS
  18         default "0"
  19         help
  20           This controls the amount of debugging messages produced by the JFFS2
  21           code. Set it to zero for use in production systems. For evaluation,
  22           testing and debugging, it's advisable to set it to one. This will
  23           enable a few assertions and will print debugging messages at the
  24           KERN_DEBUG loglevel, where they won't normally be visible. Level 2
  25           is unlikely to be useful - it enables extra debugging in certain
  26           areas which at one point needed debugging, but when the bugs were
  27           located and fixed, the detailed messages were relegated to level 2.
  28
  29           If reporting bugs, please try to have available a full dump of the
  30           messages at debug level 1 while the misbehaviour was occurring.
  31
  32 config JFFS2_FS_WRITEBUFFER
  33         bool "JFFS2 write-buffering support"
  34         depends on JFFS2_FS
  35         default y
  36         help
  37           This enables the write-buffering support in JFFS2.
  38
  39           This functionality is required to support JFFS2 on the following
  40           types of flash devices:
  41             - NAND flash
  42             - NOR flash with transparent ECC
  43             - DataFlash
  44
  45 config JFFS2_FS_WBUF_VERIFY
  46         bool "Verify JFFS2 write-buffer reads"
  47         depends on JFFS2_FS_WRITEBUFFER
  48         default n
  49         help
  50           This causes JFFS2 to read back every page written through the
  51           write-buffer, and check for errors.
  52
  53 config JFFS2_SUMMARY
  54         bool "JFFS2 summary support"
  55         depends on JFFS2_FS
  56         default n
  57         help
  58           This feature makes it possible to use summary information
  59           for faster filesystem mount.
  60
  61           The summary information can be inserted into a filesystem image
  62           by the utility 'sumtool'.
  63
  64           If unsure, say 'N'.
  65
  66 config JFFS2_FS_XATTR
  67         bool "JFFS2 XATTR support"
  68         depends on JFFS2_FS
  69         default n
  70         help
  71           Extended attributes are name:value pairs associated with inodes by
  72           the kernel or by users (see the attr(5) manual page 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           If you don't know what Access Control Lists are, say N
  86
  87 config JFFS2_FS_SECURITY
  88         bool "JFFS2 Security Labels"
  89         depends on JFFS2_FS_XATTR
  90         default y
  91         help
  92           Security labels support alternative access control models
  93           implemented by security modules like SELinux.  This option
  94           enables an extended attribute handler for file security
  95           labels in the jffs2 filesystem.
  96
  97           If you are not using a security module that requires using
  98           extended attributes for file security labels, say N.
  99
 100 config JFFS2_COMPRESSION_OPTIONS
 101         bool "Advanced compression options for JFFS2"
 102         depends on JFFS2_FS
 103         default n
 104         help
 105           Enabling this option allows you to explicitly choose which
 106           compression modules, if any, are enabled in JFFS2. Removing
 107           compressors can mean you cannot read existing file systems,
 108           and enabling experimental compressors can mean that you
 109           write a file system which cannot be read by a standard kernel.
 110
 111           If unsure, you should _definitely_ say 'N'.
 112
 113 config JFFS2_ZLIB
 114         bool "JFFS2 ZLIB compression support" if JFFS2_COMPRESSION_OPTIONS
 115         select ZLIB_INFLATE
 116         select ZLIB_DEFLATE
 117         depends on JFFS2_FS
 118         default y
 119         help
 120           Zlib is designed to be a free, general-purpose, legally unencumbered,
 121           lossless data-compression library for use on virtually any computer
 122           hardware and operating system. See <http://www.gzip.org/zlib/> for
 123           further information.
 124
 125           Say 'Y' if unsure.
 126
 127 config JFFS2_LZO
 128         bool "JFFS2 LZO compression support" if JFFS2_COMPRESSION_OPTIONS
 129         select LZO_COMPRESS
 130         select LZO_DECOMPRESS
 131         depends on JFFS2_FS
 132         default n
 133         help
 134           minilzo-based compression. Generally works better than Zlib.
 135
 136           This feature was added in July, 2007. Say 'N' if you need
 137           compatibility with older bootloaders or kernels.
 138
 139 config JFFS2_RTIME
 140         bool "JFFS2 RTIME compression support" if JFFS2_COMPRESSION_OPTIONS
 141         depends on JFFS2_FS
 142         default y
 143         help
 144           Rtime does manage to recompress already-compressed data. Say 'Y' if unsure.
 145
 146 config JFFS2_RUBIN
 147         bool "JFFS2 RUBIN compression support" if JFFS2_COMPRESSION_OPTIONS
 148         depends on JFFS2_FS
 149         default n
 150         help
 151           RUBINMIPS and DYNRUBIN compressors. Say 'N' if unsure.
 152
 153 choice
 154         prompt "JFFS2 default compression mode" if JFFS2_COMPRESSION_OPTIONS
 155         default JFFS2_CMODE_PRIORITY
 156         depends on JFFS2_FS
 157         help
 158           You can set here the default compression mode of JFFS2 from
 159           the available compression modes. Don't touch if unsure.
 160
 161 config JFFS2_CMODE_NONE
 162         bool "no compression"
 163         help
 164           Uses no compression.
 165
 166 config JFFS2_CMODE_PRIORITY
 167         bool "priority"
 168         help
 169           Tries the compressors in a predefined order and chooses the first
 170           successful one.
 171
 172 config JFFS2_CMODE_SIZE
 173         bool "size"
 174         help
 175           Tries all compressors and chooses the one which has the smallest
 176           result.
 177
 178 config JFFS2_CMODE_FAVOURLZO
 179         bool "Favour LZO"
 180         help
 181           Tries all compressors and chooses the one which has the smallest
 182           result but gives some preference to LZO (which has faster
 183           decompression) at the expense of size.
 184
 185 endchoice