Kconfig 2.1 KB

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  1. # SPDX-License-Identifier: GPL-2.0-only
  2. config CRAMFS
  3. tristate "Compressed ROM file system support (cramfs)"
  4. select ZLIB_INFLATE
  5. help
  6. Saying Y here includes support for CramFs (Compressed ROM File
  7. System). CramFs is designed to be a simple, small, and compressed
  8. file system for ROM based embedded systems. CramFs is read-only,
  9. limited to 256MB file systems (with 16MB files), and doesn't support
  10. 16/32 bits uid/gid, hard links and timestamps.
  11. See <file:Documentation/filesystems/cramfs.rst> and
  12. <file:fs/cramfs/README> for further information.
  13. To compile this as a module, choose M here: the module will be called
  14. cramfs. Note that the root file system (the one containing the
  15. directory /) cannot be compiled as a module.
  16. This filesystem is limited in capabilities and performance on
  17. purpose to remain small and low on RAM usage. It is most suitable
  18. for small embedded systems. If you have ample RAM to spare, you may
  19. consider a more capable compressed filesystem such as SquashFS
  20. which is much better in terms of performance and features.
  21. If unsure, say N.
  22. config CRAMFS_BLOCKDEV
  23. bool "Support CramFs image over a regular block device" if EXPERT
  24. depends on CRAMFS && BLOCK
  25. default y
  26. help
  27. This option allows the CramFs driver to load data from a regular
  28. block device such a disk partition or a ramdisk.
  29. config CRAMFS_MTD
  30. bool "Support CramFs image directly mapped in physical memory"
  31. depends on CRAMFS && CRAMFS <= MTD
  32. default y if !CRAMFS_BLOCKDEV
  33. help
  34. This option allows the CramFs driver to load data directly from
  35. a linear adressed memory range (usually non volatile memory
  36. like flash) instead of going through the block device layer.
  37. This saves some memory since no intermediate buffering is
  38. necessary.
  39. The location of the CramFs image is determined by a
  40. MTD device capable of direct memory mapping e.g. from
  41. the 'physmap' map driver or a resulting MTD partition.
  42. For example, this would mount the cramfs image stored in
  43. the MTD partition named "xip_fs" on the /mnt mountpoint:
  44. mount -t cramfs mtd:xip_fs /mnt
  45. If unsure, say N.