config ROMFS_FS tristate "ROM file system support" depends on BLOCK ---help--- This is a very small read-only file system mainly intended for initial ram disks of installation disks, but it could be used for other read-only media as well. Read for details. To compile this file system support as a module, choose M here: the module will be called romfs. Note that the file system of your root partition (the one containing the directory /) cannot be a module. If you don't know whether you need it, then you don't need it: answer N.