18c2ecf20Sopenharmony_ci# SPDX-License-Identifier: GPL-2.0-only 28c2ecf20Sopenharmony_ciconfig ROMFS_FS 38c2ecf20Sopenharmony_ci tristate "ROM file system support" 48c2ecf20Sopenharmony_ci depends on BLOCK || MTD 58c2ecf20Sopenharmony_ci help 68c2ecf20Sopenharmony_ci This is a very small read-only file system mainly intended for 78c2ecf20Sopenharmony_ci initial ram disks of installation disks, but it could be used for 88c2ecf20Sopenharmony_ci other read-only media as well. Read 98c2ecf20Sopenharmony_ci <file:Documentation/filesystems/romfs.rst> for details. 108c2ecf20Sopenharmony_ci 118c2ecf20Sopenharmony_ci To compile this file system support as a module, choose M here: the 128c2ecf20Sopenharmony_ci module will be called romfs. Note that the file system of your 138c2ecf20Sopenharmony_ci root partition (the one containing the directory /) cannot be a 148c2ecf20Sopenharmony_ci module. 158c2ecf20Sopenharmony_ci 168c2ecf20Sopenharmony_ci If you don't know whether you need it, then you don't need it: 178c2ecf20Sopenharmony_ci answer N. 188c2ecf20Sopenharmony_ci 198c2ecf20Sopenharmony_ci# 208c2ecf20Sopenharmony_ci# Select the backing stores to be supported 218c2ecf20Sopenharmony_ci# 228c2ecf20Sopenharmony_cichoice 238c2ecf20Sopenharmony_ci prompt "RomFS backing stores" 248c2ecf20Sopenharmony_ci depends on ROMFS_FS 258c2ecf20Sopenharmony_ci default ROMFS_BACKED_BY_BLOCK 268c2ecf20Sopenharmony_ci help 278c2ecf20Sopenharmony_ci Select the backing stores to be supported. 288c2ecf20Sopenharmony_ci 298c2ecf20Sopenharmony_ciconfig ROMFS_BACKED_BY_BLOCK 308c2ecf20Sopenharmony_ci bool "Block device-backed ROM file system support" 318c2ecf20Sopenharmony_ci depends on BLOCK 328c2ecf20Sopenharmony_ci help 338c2ecf20Sopenharmony_ci This permits ROMFS to use block devices buffered through the page 348c2ecf20Sopenharmony_ci cache as the medium from which to retrieve data. It does not allow 358c2ecf20Sopenharmony_ci direct mapping of the medium. 368c2ecf20Sopenharmony_ci 378c2ecf20Sopenharmony_ci If unsure, answer Y. 388c2ecf20Sopenharmony_ci 398c2ecf20Sopenharmony_ciconfig ROMFS_BACKED_BY_MTD 408c2ecf20Sopenharmony_ci bool "MTD-backed ROM file system support" 418c2ecf20Sopenharmony_ci depends on MTD=y || (ROMFS_FS=m && MTD) 428c2ecf20Sopenharmony_ci help 438c2ecf20Sopenharmony_ci This permits ROMFS to use MTD based devices directly, without the 448c2ecf20Sopenharmony_ci intercession of the block layer (which may have been disabled). It 458c2ecf20Sopenharmony_ci also allows direct mapping of MTD devices through romfs files under 468c2ecf20Sopenharmony_ci NOMMU conditions if the underlying device is directly addressable by 478c2ecf20Sopenharmony_ci the CPU. 488c2ecf20Sopenharmony_ci 498c2ecf20Sopenharmony_ci If unsure, answer Y. 508c2ecf20Sopenharmony_ci 518c2ecf20Sopenharmony_ciconfig ROMFS_BACKED_BY_BOTH 528c2ecf20Sopenharmony_ci bool "Both the above" 538c2ecf20Sopenharmony_ci depends on BLOCK && (MTD=y || (ROMFS_FS=m && MTD)) 548c2ecf20Sopenharmony_ciendchoice 558c2ecf20Sopenharmony_ci 568c2ecf20Sopenharmony_ci 578c2ecf20Sopenharmony_ciconfig ROMFS_ON_BLOCK 588c2ecf20Sopenharmony_ci bool 598c2ecf20Sopenharmony_ci default y if ROMFS_BACKED_BY_BLOCK || ROMFS_BACKED_BY_BOTH 608c2ecf20Sopenharmony_ci 618c2ecf20Sopenharmony_ciconfig ROMFS_ON_MTD 628c2ecf20Sopenharmony_ci bool 638c2ecf20Sopenharmony_ci default y if ROMFS_BACKED_BY_MTD || ROMFS_BACKED_BY_BOTH 64