projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| ec8f24b7 | 1 | # SPDX-License-Identifier: GPL-2.0-only |
| 2a22783b | 2 | config CRAMFS |
| 8d59598c | 3 | tristate "Compressed ROM file system support (cramfs)" |
| 2a22783b AD |
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 | ||
| 0c1bc6b8 | 12 | See <file:Documentation/filesystems/cramfs.rst> and |
| 2a22783b AD |
13 | <file:fs/cramfs/README> for further information. |
| 14 | ||
| 15 | To compile this as a module, choose M here: the module will be called | |
| 16 | cramfs. Note that the root file system (the one containing the | |
| 17 | directory /) cannot be compiled as a module. | |
| 18 | ||
| 8d59598c NP |
19 | This filesystem is limited in capabilities and performance on |
| 20 | purpose to remain small and low on RAM usage. It is most suitable | |
| 21 | for small embedded systems. If you have ample RAM to spare, you may | |
| 22 | consider a more capable compressed filesystem such as SquashFS | |
| 23 | which is much better in terms of performance and features. | |
| 54886a71 | 24 | |
| 2a22783b | 25 | If unsure, say N. |
| 99c18ce5 NP |
26 | |
| 27 | config CRAMFS_BLOCKDEV | |
| 28 | bool "Support CramFs image over a regular block device" if EXPERT | |
| 29 | depends on CRAMFS && BLOCK | |
| 30 | default y | |
| 31 | help | |
| 32 | This option allows the CramFs driver to load data from a regular | |
| 33 | block device such a disk partition or a ramdisk. | |
| 34 | ||
| 35 | config CRAMFS_MTD | |
| 36 | bool "Support CramFs image directly mapped in physical memory" | |
| a8c6db00 | 37 | depends on CRAMFS && CRAMFS <= MTD |
| 99c18ce5 NP |
38 | default y if !CRAMFS_BLOCKDEV |
| 39 | help | |
| 40 | This option allows the CramFs driver to load data directly from | |
| a1f46ff2 | 41 | a linear addressed memory range (usually non-volatile memory |
| 99c18ce5 NP |
42 | like flash) instead of going through the block device layer. |
| 43 | This saves some memory since no intermediate buffering is | |
| 44 | necessary. | |
| 45 | ||
| 46 | The location of the CramFs image is determined by a | |
| 47 | MTD device capable of direct memory mapping e.g. from | |
| 48 | the 'physmap' map driver or a resulting MTD partition. | |
| 49 | For example, this would mount the cramfs image stored in | |
| 50 | the MTD partition named "xip_fs" on the /mnt mountpoint: | |
| 51 | ||
| 52 | mount -t cramfs mtd:xip_fs /mnt | |
| 53 | ||
| 54 | If unsure, say N. |