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