1# SPDX-License-Identifier: GPL-2.0 2# 3# Block device driver configuration 4# 5 6menuconfig BLK_DEV 7 bool "Block devices" 8 depends on BLOCK 9 default y 10 help 11 Say Y here to get to see options for various different block device 12 drivers. This option alone does not add any kernel code. 13 14 If you say N, all options in this submenu will be skipped and disabled; 15 only do this if you know what you are doing. 16 17if BLK_DEV 18 19source "drivers/block/null_blk/Kconfig" 20 21config BLK_DEV_FD 22 tristate "Normal floppy disk support" 23 depends on ARCH_MAY_HAVE_PC_FDC 24 help 25 If you want to use the floppy disk drive(s) of your PC under Linux, 26 say Y. Information about this driver, especially important for IBM 27 Thinkpad users, is contained in 28 <file:Documentation/admin-guide/blockdev/floppy.rst>. 29 That file also contains the location of the Floppy driver FAQ as 30 well as location of the fdutils package used to configure additional 31 parameters of the driver at run time. 32 33 To compile this driver as a module, choose M here: the 34 module will be called floppy. 35 36config BLK_DEV_FD_RAWCMD 37 bool "Support for raw floppy disk commands (DEPRECATED)" 38 depends on BLK_DEV_FD 39 help 40 If you want to use actual physical floppies and expect to do 41 special low-level hardware accesses to them (access and use 42 non-standard formats, for example), then enable this. 43 44 Note that the code enabled by this option is rarely used and 45 might be unstable or insecure, and distros should not enable it. 46 47 Note: FDRAWCMD is deprecated and will be removed from the kernel 48 in the near future. 49 50 If unsure, say N. 51 52config AMIGA_FLOPPY 53 tristate "Amiga floppy support" 54 depends on AMIGA 55 56config ATARI_FLOPPY 57 tristate "Atari floppy support" 58 depends on ATARI 59 60config MAC_FLOPPY 61 tristate "Support for PowerMac floppy" 62 depends on PPC_PMAC && !PPC_PMAC64 63 help 64 If you have a SWIM-3 (Super Woz Integrated Machine 3; from Apple) 65 floppy controller, say Y here. Most commonly found in PowerMacs. 66 67config BLK_DEV_SWIM 68 tristate "Support for SWIM Macintosh floppy" 69 depends on M68K && MAC && !HIGHMEM 70 help 71 You should select this option if you want floppy support 72 and you don't have a II, IIfx, Q900, Q950 or AV series. 73 74config AMIGA_Z2RAM 75 tristate "Amiga Zorro II ramdisk support" 76 depends on ZORRO 77 help 78 This enables support for using Chip RAM and Zorro II RAM as a 79 ramdisk or as a swap partition. Say Y if you want to include this 80 driver in the kernel. 81 82 To compile this driver as a module, choose M here: the 83 module will be called z2ram. 84 85config N64CART 86 bool "N64 cart support" 87 depends on MACH_NINTENDO64 88 help 89 Support for the N64 cart. 90 91config CDROM 92 tristate 93 94config GDROM 95 tristate "SEGA Dreamcast GD-ROM drive" 96 depends on SH_DREAMCAST 97 select CDROM 98 help 99 A standard SEGA Dreamcast comes with a modified CD ROM drive called a 100 "GD-ROM" by SEGA to signify it is capable of reading special disks 101 with up to 1 GB of data. This drive will also read standard CD ROM 102 disks. Select this option to access any disks in your GD ROM drive. 103 Most users will want to say "Y" here. 104 You can also build this as a module which will be called gdrom. 105 106source "drivers/block/paride/Kconfig" 107 108source "drivers/block/mtip32xx/Kconfig" 109 110source "drivers/block/zram/Kconfig" 111 112config BLK_DEV_UBD 113 bool "Virtual block device" 114 depends on UML 115 help 116 The User-Mode Linux port includes a driver called UBD which will let 117 you access arbitrary files on the host computer as block devices. 118 Unless you know that you do not need such virtual block devices say 119 Y here. 120 121config BLK_DEV_UBD_SYNC 122 bool "Always do synchronous disk IO for UBD" 123 depends on BLK_DEV_UBD 124 help 125 Writes to the virtual block device are not immediately written to the 126 host's disk; this may cause problems if, for example, the User-Mode 127 Linux 'Virtual Machine' uses a journalling filesystem and the host 128 computer crashes. 129 130 Synchronous operation (i.e. always writing data to the host's disk 131 immediately) is configurable on a per-UBD basis by using a special 132 kernel command line option. Alternatively, you can say Y here to 133 turn on synchronous operation by default for all block devices. 134 135 If you're running a journalling file system (like reiserfs, for 136 example) in your virtual machine, you will want to say Y here. If 137 you care for the safety of the data in your virtual machine, Y is a 138 wise choice too. In all other cases (for example, if you're just 139 playing around with User-Mode Linux) you can choose N. 140 141config BLK_DEV_COW_COMMON 142 bool 143 default BLK_DEV_UBD 144 145config BLK_DEV_LOOP 146 tristate "Loopback device support" 147 help 148 Saying Y here will allow you to use a regular file as a block 149 device; you can then create a file system on that block device and 150 mount it just as you would mount other block devices such as hard 151 drive partitions, CD-ROM drives or floppy drives. The loop devices 152 are block special device files with major number 7 and typically 153 called /dev/loop0, /dev/loop1 etc. 154 155 This is useful if you want to check an ISO 9660 file system before 156 burning the CD, or if you want to use floppy images without first 157 writing them to floppy. Furthermore, some Linux distributions avoid 158 the need for a dedicated Linux partition by keeping their complete 159 root file system inside a DOS FAT file using this loop device 160 driver. 161 162 To use the loop device, you need the losetup utility, found in the 163 util-linux package, see 164 <https://www.kernel.org/pub/linux/utils/util-linux/>. 165 166 The loop device driver can also be used to "hide" a file system in 167 a disk partition, floppy, or regular file, either using encryption 168 (scrambling the data) or steganography (hiding the data in the low 169 bits of, say, a sound file). This is also safe if the file resides 170 on a remote file server. 171 172 Note that this loop device has nothing to do with the loopback 173 device used for network connections from the machine to itself. 174 175 To compile this driver as a module, choose M here: the 176 module will be called loop. 177 178 Most users will answer N here. 179 180config BLK_DEV_LOOP_MIN_COUNT 181 int "Number of loop devices to pre-create at init time" 182 depends on BLK_DEV_LOOP 183 default 8 184 help 185 Static number of loop devices to be unconditionally pre-created 186 at init time. 187 188 This default value can be overwritten on the kernel command 189 line or with module-parameter loop.max_loop. 190 191 The historic default is 8. If a late 2011 version of losetup(8) 192 is used, it can be set to 0, since needed loop devices can be 193 dynamically allocated with the /dev/loop-control interface. 194 195source "drivers/block/drbd/Kconfig" 196 197config BLK_DEV_NBD 198 tristate "Network block device support" 199 depends on NET 200 help 201 Saying Y here will allow your computer to be a client for network 202 block devices, i.e. it will be able to use block devices exported by 203 servers (mount file systems on them etc.). Communication between 204 client and server works over TCP/IP networking, but to the client 205 program this is hidden: it looks like a regular local file access to 206 a block device special file such as /dev/nd0. 207 208 Network block devices also allows you to run a block-device in 209 userland (making server and client physically the same computer, 210 communicating using the loopback network device). 211 212 Read <file:Documentation/admin-guide/blockdev/nbd.rst> for more information, 213 especially about where to find the server code, which runs in user 214 space and does not need special kernel support. 215 216 Note that this has nothing to do with the network file systems NFS 217 or Coda; you can say N here even if you intend to use NFS or Coda. 218 219 To compile this driver as a module, choose M here: the 220 module will be called nbd. 221 222 If unsure, say N. 223 224config BLK_DEV_RAM 225 tristate "RAM block device support" 226 help 227 Saying Y here will allow you to use a portion of your RAM memory as 228 a block device, so that you can make file systems on it, read and 229 write to it and do all the other things that you can do with normal 230 block devices (such as hard drives). It is usually used to load and 231 store a copy of a minimal root file system off of a floppy into RAM 232 during the initial install of Linux. 233 234 Note that the kernel command line option "ramdisk=XX" is now obsolete. 235 For details, read <file:Documentation/admin-guide/blockdev/ramdisk.rst>. 236 237 To compile this driver as a module, choose M here: the 238 module will be called brd. An alias "rd" has been defined 239 for historical reasons. 240 241 Most normal users won't need the RAM disk functionality, and can 242 thus say N here. 243 244config BLK_DEV_RAM_COUNT 245 int "Default number of RAM disks" 246 default "16" 247 depends on BLK_DEV_RAM 248 help 249 The default value is 16 RAM disks. Change this if you know what you 250 are doing. If you boot from a filesystem that needs to be extracted 251 in memory, you will need at least one RAM disk (e.g. root on cramfs). 252 253config BLK_DEV_RAM_SIZE 254 int "Default RAM disk size (kbytes)" 255 depends on BLK_DEV_RAM 256 default "4096" 257 help 258 The default value is 4096 kilobytes. Only change this if you know 259 what you are doing. 260 261config ATA_OVER_ETH 262 tristate "ATA over Ethernet support" 263 depends on NET 264 help 265 This driver provides Support for ATA over Ethernet block 266 devices like the Coraid EtherDrive (R) Storage Blade. 267 268config SUNVDC 269 tristate "Sun Virtual Disk Client support" 270 depends on SUN_LDOMS 271 help 272 Support for virtual disk devices as a client under Sun 273 Logical Domains. 274 275source "drivers/s390/block/Kconfig" 276 277config XEN_BLKDEV_FRONTEND 278 tristate "Xen virtual block device support" 279 depends on XEN 280 default y 281 select XEN_XENBUS_FRONTEND 282 help 283 This driver implements the front-end of the Xen virtual 284 block device driver. It communicates with a back-end driver 285 in another domain which drives the actual block device. 286 287config XEN_BLKDEV_BACKEND 288 tristate "Xen block-device backend driver" 289 depends on XEN_BACKEND 290 help 291 The block-device backend driver allows the kernel to export its 292 block devices to other guests via a high-performance shared-memory 293 interface. 294 295 The corresponding Linux frontend driver is enabled by the 296 CONFIG_XEN_BLKDEV_FRONTEND configuration option. 297 298 The backend driver attaches itself to a any block device specified 299 in the XenBus configuration. There are no limits to what the block 300 device as long as it has a major and minor. 301 302 If you are compiling a kernel to run in a Xen block backend driver 303 domain (often this is domain 0) you should say Y here. To 304 compile this driver as a module, chose M here: the module 305 will be called xen-blkback. 306 307 308config VIRTIO_BLK 309 tristate "Virtio block driver" 310 depends on VIRTIO 311 select SG_POOL 312 help 313 This is the virtual block driver for virtio. It can be used with 314 QEMU based VMMs (like KVM or Xen). Say Y or M. 315 316config BLK_DEV_RBD 317 tristate "Rados block device (RBD)" 318 depends on INET && BLOCK 319 select CEPH_LIB 320 select LIBCRC32C 321 select CRYPTO_AES 322 select CRYPTO 323 help 324 Say Y here if you want include the Rados block device, which stripes 325 a block device over objects stored in the Ceph distributed object 326 store. 327 328 More information at http://ceph.newdream.net/. 329 330 If unsure, say N. 331 332config BLK_DEV_UBLK 333 tristate "Userspace block driver (Experimental)" 334 select IO_URING 335 help 336 io_uring based userspace block driver. Together with ublk server, ublk 337 has been working well, but interface with userspace or command data 338 definition isn't finalized yet, and might change according to future 339 requirement, so mark is as experimental now. 340 341 Say Y if you want to get better performance because task_work_add() 342 can be used in IO path for replacing io_uring cmd, which will become 343 shared between IO tasks and ubq daemon, meantime task_work_add() can 344 can handle batch more effectively, but task_work_add() isn't exported 345 for module, so ublk has to be built to kernel. 346 347source "drivers/block/rnbd/Kconfig" 348 349endif # BLK_DEV 350