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 106config PARIDE 107 tristate "Parallel port IDE device support" 108 depends on PARPORT_PC 109 help 110 There are many external CD-ROM and disk devices that connect through 111 your computer's parallel port. Most of them are actually IDE devices 112 using a parallel port IDE adapter. This option enables the PARIDE 113 subsystem which contains drivers for many of these external drives. 114 Read <file:Documentation/admin-guide/blockdev/paride.rst> for more information. 115 116 If you have said Y to the "Parallel-port support" configuration 117 option, you may share a single port between your printer and other 118 parallel port devices. Answer Y to build PARIDE support into your 119 kernel, or M if you would like to build it as a loadable module. If 120 your parallel port support is in a loadable module, you must build 121 PARIDE as a module. If you built PARIDE support into your kernel, 122 you may still build the individual protocol modules and high-level 123 drivers as loadable modules. If you build this support as a module, 124 it will be called paride. 125 126 To use the PARIDE support, you must say Y or M here and also to at 127 least one high-level driver (e.g. "Parallel port IDE disks", 128 "Parallel port ATAPI CD-ROMs", "Parallel port ATAPI disks" etc.) and 129 to at least one protocol driver (e.g. "ATEN EH-100 protocol", 130 "MicroSolutions backpack protocol", "DataStor Commuter protocol" 131 etc.). 132 133source "drivers/block/paride/Kconfig" 134 135source "drivers/block/mtip32xx/Kconfig" 136 137source "drivers/block/zram/Kconfig" 138 139config BLK_DEV_UBD 140 bool "Virtual block device" 141 depends on UML 142 help 143 The User-Mode Linux port includes a driver called UBD which will let 144 you access arbitrary files on the host computer as block devices. 145 Unless you know that you do not need such virtual block devices say 146 Y here. 147 148config BLK_DEV_UBD_SYNC 149 bool "Always do synchronous disk IO for UBD" 150 depends on BLK_DEV_UBD 151 help 152 Writes to the virtual block device are not immediately written to the 153 host's disk; this may cause problems if, for example, the User-Mode 154 Linux 'Virtual Machine' uses a journalling filesystem and the host 155 computer crashes. 156 157 Synchronous operation (i.e. always writing data to the host's disk 158 immediately) is configurable on a per-UBD basis by using a special 159 kernel command line option. Alternatively, you can say Y here to 160 turn on synchronous operation by default for all block devices. 161 162 If you're running a journalling file system (like reiserfs, for 163 example) in your virtual machine, you will want to say Y here. If 164 you care for the safety of the data in your virtual machine, Y is a 165 wise choice too. In all other cases (for example, if you're just 166 playing around with User-Mode Linux) you can choose N. 167 168config BLK_DEV_COW_COMMON 169 bool 170 default BLK_DEV_UBD 171 172config BLK_DEV_LOOP 173 tristate "Loopback device support" 174 help 175 Saying Y here will allow you to use a regular file as a block 176 device; you can then create a file system on that block device and 177 mount it just as you would mount other block devices such as hard 178 drive partitions, CD-ROM drives or floppy drives. The loop devices 179 are block special device files with major number 7 and typically 180 called /dev/loop0, /dev/loop1 etc. 181 182 This is useful if you want to check an ISO 9660 file system before 183 burning the CD, or if you want to use floppy images without first 184 writing them to floppy. Furthermore, some Linux distributions avoid 185 the need for a dedicated Linux partition by keeping their complete 186 root file system inside a DOS FAT file using this loop device 187 driver. 188 189 To use the loop device, you need the losetup utility, found in the 190 util-linux package, see 191 <https://www.kernel.org/pub/linux/utils/util-linux/>. 192 193 The loop device driver can also be used to "hide" a file system in 194 a disk partition, floppy, or regular file, either using encryption 195 (scrambling the data) or steganography (hiding the data in the low 196 bits of, say, a sound file). This is also safe if the file resides 197 on a remote file server. 198 199 Note that this loop device has nothing to do with the loopback 200 device used for network connections from the machine to itself. 201 202 To compile this driver as a module, choose M here: the 203 module will be called loop. 204 205 Most users will answer N here. 206 207config BLK_DEV_LOOP_MIN_COUNT 208 int "Number of loop devices to pre-create at init time" 209 depends on BLK_DEV_LOOP 210 default 8 211 help 212 Static number of loop devices to be unconditionally pre-created 213 at init time. 214 215 This default value can be overwritten on the kernel command 216 line or with module-parameter loop.max_loop. 217 218 The historic default is 8. If a late 2011 version of losetup(8) 219 is used, it can be set to 0, since needed loop devices can be 220 dynamically allocated with the /dev/loop-control interface. 221 222source "drivers/block/drbd/Kconfig" 223 224config BLK_DEV_NBD 225 tristate "Network block device support" 226 depends on NET 227 help 228 Saying Y here will allow your computer to be a client for network 229 block devices, i.e. it will be able to use block devices exported by 230 servers (mount file systems on them etc.). Communication between 231 client and server works over TCP/IP networking, but to the client 232 program this is hidden: it looks like a regular local file access to 233 a block device special file such as /dev/nd0. 234 235 Network block devices also allows you to run a block-device in 236 userland (making server and client physically the same computer, 237 communicating using the loopback network device). 238 239 Read <file:Documentation/admin-guide/blockdev/nbd.rst> for more information, 240 especially about where to find the server code, which runs in user 241 space and does not need special kernel support. 242 243 Note that this has nothing to do with the network file systems NFS 244 or Coda; you can say N here even if you intend to use NFS or Coda. 245 246 To compile this driver as a module, choose M here: the 247 module will be called nbd. 248 249 If unsure, say N. 250 251config BLK_DEV_RAM 252 tristate "RAM block device support" 253 help 254 Saying Y here will allow you to use a portion of your RAM memory as 255 a block device, so that you can make file systems on it, read and 256 write to it and do all the other things that you can do with normal 257 block devices (such as hard drives). It is usually used to load and 258 store a copy of a minimal root file system off of a floppy into RAM 259 during the initial install of Linux. 260 261 Note that the kernel command line option "ramdisk=XX" is now obsolete. 262 For details, read <file:Documentation/admin-guide/blockdev/ramdisk.rst>. 263 264 To compile this driver as a module, choose M here: the 265 module will be called brd. An alias "rd" has been defined 266 for historical reasons. 267 268 Most normal users won't need the RAM disk functionality, and can 269 thus say N here. 270 271config BLK_DEV_RAM_COUNT 272 int "Default number of RAM disks" 273 default "16" 274 depends on BLK_DEV_RAM 275 help 276 The default value is 16 RAM disks. Change this if you know what you 277 are doing. If you boot from a filesystem that needs to be extracted 278 in memory, you will need at least one RAM disk (e.g. root on cramfs). 279 280config BLK_DEV_RAM_SIZE 281 int "Default RAM disk size (kbytes)" 282 depends on BLK_DEV_RAM 283 default "4096" 284 help 285 The default value is 4096 kilobytes. Only change this if you know 286 what you are doing. 287 288config CDROM_PKTCDVD 289 tristate "Packet writing on CD/DVD media (DEPRECATED)" 290 depends on !UML 291 depends on SCSI 292 select CDROM 293 help 294 Note: This driver is deprecated and will be removed from the 295 kernel in the near future! 296 297 If you have a CDROM/DVD drive that supports packet writing, say 298 Y to include support. It should work with any MMC/Mt Fuji 299 compliant ATAPI or SCSI drive, which is just about any newer 300 DVD/CD writer. 301 302 Currently only writing to CD-RW, DVD-RW, DVD+RW and DVDRAM discs 303 is possible. 304 DVD-RW disks must be in restricted overwrite mode. 305 306 See the file <file:Documentation/cdrom/packet-writing.rst> 307 for further information on the use of this driver. 308 309 To compile this driver as a module, choose M here: the 310 module will be called pktcdvd. 311 312config CDROM_PKTCDVD_BUFFERS 313 int "Free buffers for data gathering" 314 depends on CDROM_PKTCDVD 315 default "8" 316 help 317 This controls the maximum number of active concurrent packets. More 318 concurrent packets can increase write performance, but also require 319 more memory. Each concurrent packet will require approximately 64Kb 320 of non-swappable kernel memory, memory which will be allocated when 321 a disc is opened for writing. 322 323config CDROM_PKTCDVD_WCACHE 324 bool "Enable write caching" 325 depends on CDROM_PKTCDVD 326 help 327 If enabled, write caching will be set for the CD-R/W device. For now 328 this option is dangerous unless the CD-RW media is known good, as we 329 don't do deferred write error handling yet. 330 331config ATA_OVER_ETH 332 tristate "ATA over Ethernet support" 333 depends on NET 334 help 335 This driver provides Support for ATA over Ethernet block 336 devices like the Coraid EtherDrive (R) Storage Blade. 337 338config SUNVDC 339 tristate "Sun Virtual Disk Client support" 340 depends on SUN_LDOMS 341 help 342 Support for virtual disk devices as a client under Sun 343 Logical Domains. 344 345source "drivers/s390/block/Kconfig" 346 347config XEN_BLKDEV_FRONTEND 348 tristate "Xen virtual block device support" 349 depends on XEN 350 default y 351 select XEN_XENBUS_FRONTEND 352 help 353 This driver implements the front-end of the Xen virtual 354 block device driver. It communicates with a back-end driver 355 in another domain which drives the actual block device. 356 357config XEN_BLKDEV_BACKEND 358 tristate "Xen block-device backend driver" 359 depends on XEN_BACKEND 360 help 361 The block-device backend driver allows the kernel to export its 362 block devices to other guests via a high-performance shared-memory 363 interface. 364 365 The corresponding Linux frontend driver is enabled by the 366 CONFIG_XEN_BLKDEV_FRONTEND configuration option. 367 368 The backend driver attaches itself to a any block device specified 369 in the XenBus configuration. There are no limits to what the block 370 device as long as it has a major and minor. 371 372 If you are compiling a kernel to run in a Xen block backend driver 373 domain (often this is domain 0) you should say Y here. To 374 compile this driver as a module, chose M here: the module 375 will be called xen-blkback. 376 377 378config VIRTIO_BLK 379 tristate "Virtio block driver" 380 depends on VIRTIO 381 select SG_POOL 382 help 383 This is the virtual block driver for virtio. It can be used with 384 QEMU based VMMs (like KVM or Xen). Say Y or M. 385 386config BLK_DEV_RBD 387 tristate "Rados block device (RBD)" 388 depends on INET && BLOCK 389 select CEPH_LIB 390 select LIBCRC32C 391 select CRYPTO_AES 392 select CRYPTO 393 help 394 Say Y here if you want include the Rados block device, which stripes 395 a block device over objects stored in the Ceph distributed object 396 store. 397 398 More information at http://ceph.newdream.net/. 399 400 If unsure, say N. 401 402config BLK_DEV_UBLK 403 tristate "Userspace block driver (Experimental)" 404 select IO_URING 405 help 406 io_uring based userspace block driver. Together with ublk server, ublk 407 has been working well, but interface with userspace or command data 408 definition isn't finalized yet, and might change according to future 409 requirement, so mark is as experimental now. 410 411 Say Y if you want to get better performance because task_work_add() 412 can be used in IO path for replacing io_uring cmd, which will become 413 shared between IO tasks and ubq daemon, meantime task_work_add() can 414 can handle batch more effectively, but task_work_add() isn't exported 415 for module, so ublk has to be built to kernel. 416 417source "drivers/block/rnbd/Kconfig" 418 419endif # BLK_DEV 420