1# SPDX-License-Identifier: GPL-2.0-only 2config ROMFS_FS 3 tristate "ROM file system support" 4 depends on BLOCK || MTD 5 help 6 This is a very small read-only file system mainly intended for 7 initial ram disks of installation disks, but it could be used for 8 other read-only media as well. Read 9 <file:Documentation/filesystems/romfs.rst> for details. 10 11 To compile this file system support as a module, choose M here: the 12 module will be called romfs. Note that the file system of your 13 root partition (the one containing the directory /) cannot be a 14 module. 15 16 If you don't know whether you need it, then you don't need it: 17 answer N. 18 19# 20# Select the backing stores to be supported 21# 22choice 23 prompt "RomFS backing stores" 24 depends on ROMFS_FS 25 default ROMFS_BACKED_BY_BLOCK 26 help 27 Select the backing stores to be supported. 28 29config ROMFS_BACKED_BY_BLOCK 30 bool "Block device-backed ROM file system support" 31 depends on BLOCK 32 help 33 This permits ROMFS to use block devices buffered through the page 34 cache as the medium from which to retrieve data. It does not allow 35 direct mapping of the medium. 36 37 If unsure, answer Y. 38 39config ROMFS_BACKED_BY_MTD 40 bool "MTD-backed ROM file system support" 41 depends on MTD=y || (ROMFS_FS=m && MTD) 42 help 43 This permits ROMFS to use MTD based devices directly, without the 44 intercession of the block layer (which may have been disabled). It 45 also allows direct mapping of MTD devices through romfs files under 46 NOMMU conditions if the underlying device is directly addressable by 47 the CPU. 48 49 If unsure, answer Y. 50 51config ROMFS_BACKED_BY_BOTH 52 bool "Both the above" 53 depends on BLOCK && (MTD=y || (ROMFS_FS=m && MTD)) 54endchoice 55 56 57config ROMFS_ON_BLOCK 58 bool 59 default y if ROMFS_BACKED_BY_BLOCK || ROMFS_BACKED_BY_BOTH 60 select BUFFER_HEAD 61 62config ROMFS_ON_MTD 63 bool 64 default y if ROMFS_BACKED_BY_MTD || ROMFS_BACKED_BY_BOTH 65