162306a36Sopenharmony_ci# SPDX-License-Identifier: GPL-2.0-only 262306a36Sopenharmony_ciconfig ROMFS_FS 362306a36Sopenharmony_ci tristate "ROM file system support" 462306a36Sopenharmony_ci depends on BLOCK || MTD 562306a36Sopenharmony_ci help 662306a36Sopenharmony_ci This is a very small read-only file system mainly intended for 762306a36Sopenharmony_ci initial ram disks of installation disks, but it could be used for 862306a36Sopenharmony_ci other read-only media as well. Read 962306a36Sopenharmony_ci <file:Documentation/filesystems/romfs.rst> for details. 1062306a36Sopenharmony_ci 1162306a36Sopenharmony_ci To compile this file system support as a module, choose M here: the 1262306a36Sopenharmony_ci module will be called romfs. Note that the file system of your 1362306a36Sopenharmony_ci root partition (the one containing the directory /) cannot be a 1462306a36Sopenharmony_ci module. 1562306a36Sopenharmony_ci 1662306a36Sopenharmony_ci If you don't know whether you need it, then you don't need it: 1762306a36Sopenharmony_ci answer N. 1862306a36Sopenharmony_ci 1962306a36Sopenharmony_ci# 2062306a36Sopenharmony_ci# Select the backing stores to be supported 2162306a36Sopenharmony_ci# 2262306a36Sopenharmony_cichoice 2362306a36Sopenharmony_ci prompt "RomFS backing stores" 2462306a36Sopenharmony_ci depends on ROMFS_FS 2562306a36Sopenharmony_ci default ROMFS_BACKED_BY_BLOCK 2662306a36Sopenharmony_ci help 2762306a36Sopenharmony_ci Select the backing stores to be supported. 2862306a36Sopenharmony_ci 2962306a36Sopenharmony_ciconfig ROMFS_BACKED_BY_BLOCK 3062306a36Sopenharmony_ci bool "Block device-backed ROM file system support" 3162306a36Sopenharmony_ci depends on BLOCK 3262306a36Sopenharmony_ci help 3362306a36Sopenharmony_ci This permits ROMFS to use block devices buffered through the page 3462306a36Sopenharmony_ci cache as the medium from which to retrieve data. It does not allow 3562306a36Sopenharmony_ci direct mapping of the medium. 3662306a36Sopenharmony_ci 3762306a36Sopenharmony_ci If unsure, answer Y. 3862306a36Sopenharmony_ci 3962306a36Sopenharmony_ciconfig ROMFS_BACKED_BY_MTD 4062306a36Sopenharmony_ci bool "MTD-backed ROM file system support" 4162306a36Sopenharmony_ci depends on MTD=y || (ROMFS_FS=m && MTD) 4262306a36Sopenharmony_ci help 4362306a36Sopenharmony_ci This permits ROMFS to use MTD based devices directly, without the 4462306a36Sopenharmony_ci intercession of the block layer (which may have been disabled). It 4562306a36Sopenharmony_ci also allows direct mapping of MTD devices through romfs files under 4662306a36Sopenharmony_ci NOMMU conditions if the underlying device is directly addressable by 4762306a36Sopenharmony_ci the CPU. 4862306a36Sopenharmony_ci 4962306a36Sopenharmony_ci If unsure, answer Y. 5062306a36Sopenharmony_ci 5162306a36Sopenharmony_ciconfig ROMFS_BACKED_BY_BOTH 5262306a36Sopenharmony_ci bool "Both the above" 5362306a36Sopenharmony_ci depends on BLOCK && (MTD=y || (ROMFS_FS=m && MTD)) 5462306a36Sopenharmony_ciendchoice 5562306a36Sopenharmony_ci 5662306a36Sopenharmony_ci 5762306a36Sopenharmony_ciconfig ROMFS_ON_BLOCK 5862306a36Sopenharmony_ci bool 5962306a36Sopenharmony_ci default y if ROMFS_BACKED_BY_BLOCK || ROMFS_BACKED_BY_BOTH 6062306a36Sopenharmony_ci select BUFFER_HEAD 6162306a36Sopenharmony_ci 6262306a36Sopenharmony_ciconfig ROMFS_ON_MTD 6362306a36Sopenharmony_ci bool 6462306a36Sopenharmony_ci default y if ROMFS_BACKED_BY_MTD || ROMFS_BACKED_BY_BOTH 65