Kconfig 17 KB

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  1. # SPDX-License-Identifier: GPL-2.0
  2. #
  3. # Character device configuration
  4. #
  5. menu "Character devices"
  6. source "drivers/tty/Kconfig"
  7. config TTY_PRINTK
  8. tristate "TTY driver to output user messages via printk"
  9. depends on EXPERT && TTY
  10. default n
  11. help
  12. If you say Y here, the support for writing user messages (i.e.
  13. console messages) via printk is available.
  14. The feature is useful to inline user messages with kernel
  15. messages.
  16. In order to use this feature, you should output user messages
  17. to /dev/ttyprintk or redirect console to this TTY.
  18. If unsure, say N.
  19. config TTY_PRINTK_LEVEL
  20. depends on TTY_PRINTK
  21. int "ttyprintk log level (1-7)"
  22. range 1 7
  23. default "6"
  24. help
  25. Printk log level to use for ttyprintk messages.
  26. config PRINTER
  27. tristate "Parallel printer support"
  28. depends on PARPORT
  29. help
  30. If you intend to attach a printer to the parallel port of your Linux
  31. box (as opposed to using a serial printer; if the connector at the
  32. printer has 9 or 25 holes ["female"], then it's serial), say Y.
  33. Also read the Printing-HOWTO, available from
  34. <https://www.tldp.org/docs.html#howto>.
  35. It is possible to share one parallel port among several devices
  36. (e.g. printer and ZIP drive) and it is safe to compile the
  37. corresponding drivers into the kernel.
  38. To compile this driver as a module, choose M here and read
  39. <file:Documentation/admin-guide/parport.rst>. The module will be called lp.
  40. If you have several parallel ports, you can specify which ports to
  41. use with the "lp" kernel command line option. (Try "man bootparam"
  42. or see the documentation of your boot loader (lilo or loadlin) about
  43. how to pass options to the kernel at boot time.) The syntax of the
  44. "lp" command line option can be found in <file:drivers/char/lp.c>.
  45. If you have more than 8 printers, you need to increase the LP_NO
  46. macro in lp.c and the PARPORT_MAX macro in parport.h.
  47. config LP_CONSOLE
  48. bool "Support for console on line printer"
  49. depends on PRINTER
  50. help
  51. If you want kernel messages to be printed out as they occur, you
  52. can have a console on the printer. This option adds support for
  53. doing that; to actually get it to happen you need to pass the
  54. option "console=lp0" to the kernel at boot time.
  55. If the printer is out of paper (or off, or unplugged, or too
  56. busy..) the kernel will stall until the printer is ready again.
  57. By defining CONSOLE_LP_STRICT to 0 (at your own risk) you
  58. can make the kernel continue when this happens,
  59. but it'll lose the kernel messages.
  60. If unsure, say N.
  61. config PPDEV
  62. tristate "Support for user-space parallel port device drivers"
  63. depends on PARPORT
  64. help
  65. Saying Y to this adds support for /dev/parport device nodes. This
  66. is needed for programs that want portable access to the parallel
  67. port, for instance deviceid (which displays Plug-and-Play device
  68. IDs).
  69. This is the parallel port equivalent of SCSI generic support (sg).
  70. It is safe to say N to this -- it is not needed for normal printing
  71. or parallel port CD-ROM/disk support.
  72. To compile this driver as a module, choose M here: the
  73. module will be called ppdev.
  74. If unsure, say N.
  75. config VIRTIO_CONSOLE
  76. tristate "Virtio console"
  77. depends on TTY
  78. select HVC_DRIVER
  79. select VIRTIO
  80. help
  81. Virtio console for use with hypervisors.
  82. Also serves as a general-purpose serial device for data
  83. transfer between the guest and host. Character devices at
  84. /dev/vportNpn will be created when corresponding ports are
  85. found, where N is the device number and n is the port number
  86. within that device. If specified by the host, a sysfs
  87. attribute called 'name' will be populated with a name for
  88. the port which can be used by udev scripts to create a
  89. symlink to the device.
  90. config IBM_BSR
  91. tristate "IBM POWER Barrier Synchronization Register support"
  92. depends on PPC_PSERIES
  93. help
  94. This devices exposes a hardware mechanism for fast synchronization
  95. of threads across a large system which avoids bouncing a cacheline
  96. between several cores on a system
  97. config POWERNV_OP_PANEL
  98. tristate "IBM POWERNV Operator Panel Display support"
  99. depends on PPC_POWERNV
  100. default m
  101. help
  102. If you say Y here, a special character device node, /dev/op_panel,
  103. will be created which exposes the operator panel display on IBM
  104. Power Systems machines with FSPs.
  105. If you don't require access to the operator panel display from user
  106. space, say N.
  107. If unsure, say M here to build it as a module called powernv-op-panel.
  108. source "drivers/char/ipmi/Kconfig"
  109. config DS1620
  110. tristate "NetWinder thermometer support"
  111. depends on ARCH_NETWINDER
  112. help
  113. Say Y here to include support for the thermal management hardware
  114. found in the NetWinder. This driver allows the user to control the
  115. temperature set points and to read the current temperature.
  116. It is also possible to say M here to build it as a module (ds1620)
  117. It is recommended to be used on a NetWinder, but it is not a
  118. necessity.
  119. config NWBUTTON
  120. tristate "NetWinder Button"
  121. depends on ARCH_NETWINDER
  122. help
  123. If you say Y here and create a character device node /dev/nwbutton
  124. with major and minor numbers 10 and 158 ("man mknod"), then every
  125. time the orange button is pressed a number of times, the number of
  126. times the button was pressed will be written to that device.
  127. This is most useful for applications, as yet unwritten, which
  128. perform actions based on how many times the button is pressed in a
  129. row.
  130. Do not hold the button down for too long, as the driver does not
  131. alter the behaviour of the hardware reset circuitry attached to the
  132. button; it will still execute a hard reset if the button is held
  133. down for longer than approximately five seconds.
  134. To compile this driver as a module, choose M here: the
  135. module will be called nwbutton.
  136. Most people will answer Y to this question and "Reboot Using Button"
  137. below to be able to initiate a system shutdown from the button.
  138. config NWBUTTON_REBOOT
  139. bool "Reboot Using Button"
  140. depends on NWBUTTON
  141. help
  142. If you say Y here, then you will be able to initiate a system
  143. shutdown and reboot by pressing the orange button a number of times.
  144. The number of presses to initiate the shutdown is two by default,
  145. but this can be altered by modifying the value of NUM_PRESSES_REBOOT
  146. in nwbutton.h and recompiling the driver or, if you compile the
  147. driver as a module, you can specify the number of presses at load
  148. time with "insmod button reboot_count=<something>".
  149. config NWFLASH
  150. tristate "NetWinder flash support"
  151. depends on ARCH_NETWINDER
  152. help
  153. If you say Y here and create a character device /dev/flash with
  154. major 10 and minor 160 you can manipulate the flash ROM containing
  155. the NetWinder firmware. Be careful as accidentally overwriting the
  156. flash contents can render your computer unbootable. On no account
  157. allow random users access to this device. :-)
  158. To compile this driver as a module, choose M here: the
  159. module will be called nwflash.
  160. If you're not sure, say N.
  161. source "drivers/char/hw_random/Kconfig"
  162. config DTLK
  163. tristate "Double Talk PC internal speech card support"
  164. depends on ISA
  165. help
  166. This driver is for the DoubleTalk PC, a speech synthesizer
  167. manufactured by RC Systems (<https://www.rcsys.com/>). It is also
  168. called the `internal DoubleTalk'.
  169. To compile this driver as a module, choose M here: the
  170. module will be called dtlk.
  171. config XILINX_HWICAP
  172. tristate "Xilinx HWICAP Support"
  173. depends on MICROBLAZE
  174. help
  175. This option enables support for Xilinx Internal Configuration
  176. Access Port (ICAP) driver. The ICAP is used on Xilinx Virtex
  177. FPGA platforms to partially reconfigure the FPGA at runtime.
  178. If unsure, say N.
  179. config R3964
  180. tristate "Siemens R3964 line discipline"
  181. depends on TTY && BROKEN
  182. help
  183. This driver allows synchronous communication with devices using the
  184. Siemens R3964 packet protocol. Unless you are dealing with special
  185. hardware like PLCs, you are unlikely to need this.
  186. To compile this driver as a module, choose M here: the
  187. module will be called n_r3964.
  188. If unsure, say N.
  189. config APPLICOM
  190. tristate "Applicom intelligent fieldbus card support"
  191. depends on PCI
  192. help
  193. This driver provides the kernel-side support for the intelligent
  194. fieldbus cards made by Applicom International. More information
  195. about these cards can be found on the WWW at the address
  196. <https://www.applicom-int.com/>, or by email from David Woodhouse
  197. <dwmw2@infradead.org>.
  198. To compile this driver as a module, choose M here: the
  199. module will be called applicom.
  200. If unsure, say N.
  201. config SONYPI
  202. tristate "Sony Vaio Programmable I/O Control Device support"
  203. depends on X86_32 && PCI && INPUT
  204. help
  205. This driver enables access to the Sony Programmable I/O Control
  206. Device which can be found in many (all ?) Sony Vaio laptops.
  207. If you have one of those laptops, read
  208. <file:Documentation/admin-guide/laptops/sonypi.rst>, and say Y or M here.
  209. To compile this driver as a module, choose M here: the
  210. module will be called sonypi.
  211. config GPIO_TB0219
  212. tristate "TANBAC TB0219 GPIO support"
  213. depends on TANBAC_TB022X
  214. select GPIO_VR41XX
  215. source "drivers/char/pcmcia/Kconfig"
  216. config MWAVE
  217. tristate "ACP Modem (Mwave) support"
  218. depends on X86 && TTY
  219. select SERIAL_8250
  220. help
  221. The ACP modem (Mwave) for Linux is a WinModem. It is composed of a
  222. kernel driver and a user level application. Together these components
  223. support direct attachment to public switched telephone networks (PSTNs)
  224. and support selected world wide countries.
  225. This version of the ACP Modem driver supports the IBM Thinkpad 600E,
  226. 600, and 770 that include on board ACP modem hardware.
  227. The modem also supports the standard communications port interface
  228. (ttySx) and is compatible with the Hayes AT Command Set.
  229. The user level application needed to use this driver can be found at
  230. the IBM Linux Technology Center (LTC) web site:
  231. <http://www.ibm.com/linux/ltc/>.
  232. If you own one of the above IBM Thinkpads which has the Mwave chipset
  233. in it, say Y.
  234. To compile this driver as a module, choose M here: the
  235. module will be called mwave.
  236. config SCx200_GPIO
  237. tristate "NatSemi SCx200 GPIO Support"
  238. depends on SCx200
  239. select NSC_GPIO
  240. help
  241. Give userspace access to the GPIO pins on the National
  242. Semiconductor SCx200 processors.
  243. If compiled as a module, it will be called scx200_gpio.
  244. config PC8736x_GPIO
  245. tristate "NatSemi PC8736x GPIO Support"
  246. depends on X86_32 && !UML
  247. default SCx200_GPIO # mostly N
  248. select NSC_GPIO # needed for support routines
  249. help
  250. Give userspace access to the GPIO pins on the National
  251. Semiconductor PC-8736x (x=[03456]) SuperIO chip. The chip
  252. has multiple functional units, inc several managed by
  253. hwmon/pc87360 driver. Tested with PC-87366
  254. If compiled as a module, it will be called pc8736x_gpio.
  255. config NSC_GPIO
  256. tristate "NatSemi Base GPIO Support"
  257. depends on X86_32
  258. # selected by SCx200_GPIO and PC8736x_GPIO
  259. # what about 2 selectors differing: m != y
  260. help
  261. Common support used (and needed) by scx200_gpio and
  262. pc8736x_gpio drivers. If those drivers are built as
  263. modules, this one will be too, named nsc_gpio
  264. config DEVMEM
  265. bool "/dev/mem virtual device support"
  266. default y
  267. help
  268. Say Y here if you want to support the /dev/mem device.
  269. The /dev/mem device is used to access areas of physical
  270. memory.
  271. When in doubt, say "Y".
  272. config DEVKMEM
  273. bool "/dev/kmem virtual device support"
  274. # On arm64, VMALLOC_START < PAGE_OFFSET, which confuses kmem read/write
  275. depends on !ARM64
  276. help
  277. Say Y here if you want to support the /dev/kmem device. The
  278. /dev/kmem device is rarely used, but can be used for certain
  279. kind of kernel debugging operations.
  280. When in doubt, say "N".
  281. config NVRAM
  282. tristate "/dev/nvram support"
  283. depends on X86 || HAVE_ARCH_NVRAM_OPS
  284. default M68K || PPC
  285. help
  286. If you say Y here and create a character special file /dev/nvram
  287. with major number 10 and minor number 144 using mknod ("man mknod"),
  288. you get read and write access to the non-volatile memory.
  289. /dev/nvram may be used to view settings in NVRAM or to change them
  290. (with some utility). It could also be used to frequently
  291. save a few bits of very important data that may not be lost over
  292. power-off and for which writing to disk is too insecure. Note
  293. however that most NVRAM space in a PC belongs to the BIOS and you
  294. should NEVER idly tamper with it. See Ralf Brown's interrupt list
  295. for a guide to the use of CMOS bytes by your BIOS.
  296. This memory is conventionally called "NVRAM" on PowerPC machines,
  297. "CMOS RAM" on PCs, "NVRAM" on Ataris and "PRAM" on Macintoshes.
  298. To compile this driver as a module, choose M here: the
  299. module will be called nvram.
  300. config RAW_DRIVER
  301. tristate "RAW driver (/dev/raw/rawN)"
  302. depends on BLOCK
  303. help
  304. The raw driver permits block devices to be bound to /dev/raw/rawN.
  305. Once bound, I/O against /dev/raw/rawN uses efficient zero-copy I/O.
  306. See the raw(8) manpage for more details.
  307. Applications should preferably open the device (eg /dev/hda1)
  308. with the O_DIRECT flag.
  309. config MAX_RAW_DEVS
  310. int "Maximum number of RAW devices to support (1-65536)"
  311. depends on RAW_DRIVER
  312. range 1 65536
  313. default "256"
  314. help
  315. The maximum number of RAW devices that are supported.
  316. Default is 256. Increase this number in case you need lots of
  317. raw devices.
  318. config DEVPORT
  319. bool "/dev/port character device"
  320. depends on ISA || PCI
  321. default y
  322. help
  323. Say Y here if you want to support the /dev/port device. The /dev/port
  324. device is similar to /dev/mem, but for I/O ports.
  325. config HPET
  326. bool "HPET - High Precision Event Timer" if (X86 || IA64)
  327. default n
  328. depends on ACPI
  329. help
  330. If you say Y here, you will have a miscdevice named "/dev/hpet/". Each
  331. open selects one of the timers supported by the HPET. The timers are
  332. non-periodic and/or periodic.
  333. config HPET_MMAP
  334. bool "Allow mmap of HPET"
  335. default y
  336. depends on HPET
  337. help
  338. If you say Y here, user applications will be able to mmap
  339. the HPET registers.
  340. config HPET_MMAP_DEFAULT
  341. bool "Enable HPET MMAP access by default"
  342. default y
  343. depends on HPET_MMAP
  344. help
  345. In some hardware implementations, the page containing HPET
  346. registers may also contain other things that shouldn't be
  347. exposed to the user. This option selects the default (if
  348. kernel parameter hpet_mmap is not set) user access to the
  349. registers for applications that require it.
  350. config HANGCHECK_TIMER
  351. tristate "Hangcheck timer"
  352. depends on X86 || IA64 || PPC64 || S390
  353. help
  354. The hangcheck-timer module detects when the system has gone
  355. out to lunch past a certain margin. It can reboot the system
  356. or merely print a warning.
  357. config UV_MMTIMER
  358. tristate "UV_MMTIMER Memory mapped RTC for SGI UV"
  359. depends on X86_UV
  360. default m
  361. help
  362. The uv_mmtimer device allows direct userspace access to the
  363. UV system timer.
  364. source "drivers/char/tpm/Kconfig"
  365. config TELCLOCK
  366. tristate "Telecom clock driver for ATCA SBC"
  367. depends on X86
  368. default n
  369. help
  370. The telecom clock device is specific to the MPCBL0010 and MPCBL0050
  371. ATCA computers and allows direct userspace access to the
  372. configuration of the telecom clock configuration settings. This
  373. device is used for hardware synchronization across the ATCA backplane
  374. fabric. Upon loading, the driver exports a sysfs directory,
  375. /sys/devices/platform/telco_clock, with a number of files for
  376. controlling the behavior of this hardware.
  377. source "drivers/s390/char/Kconfig"
  378. source "drivers/char/xillybus/Kconfig"
  379. config ADI
  380. tristate "SPARC Privileged ADI driver"
  381. depends on SPARC64
  382. default m
  383. help
  384. SPARC M7 and newer processors utilize ADI (Application Data
  385. Integrity) to version and protect memory. This driver provides
  386. read/write access to the ADI versions for privileged processes.
  387. This feature is also known as MCD (Memory Corruption Detection)
  388. and SSM (Silicon Secured Memory). Intended consumers of this
  389. driver include crash and makedumpfile.
  390. endmenu
  391. config RANDOM_TRUST_CPU
  392. bool "Trust the CPU manufacturer to initialize Linux's CRNG"
  393. depends on ARCH_RANDOM
  394. default n
  395. help
  396. Assume that CPU manufacturer (e.g., Intel or AMD for RDSEED or
  397. RDRAND, IBM for the S390 and Power PC architectures) is trustworthy
  398. for the purposes of initializing Linux's CRNG. Since this is not
  399. something that can be independently audited, this amounts to trusting
  400. that CPU manufacturer (perhaps with the insistence or mandate
  401. of a Nation State's intelligence or law enforcement agencies)
  402. has not installed a hidden back door to compromise the CPU's
  403. random number generation facilities. This can also be configured
  404. at boot with "random.trust_cpu=on/off".
  405. config RANDOM_TRUST_BOOTLOADER
  406. bool "Trust the bootloader to initialize Linux's CRNG"
  407. help
  408. Some bootloaders can provide entropy to increase the kernel's initial
  409. device randomness. Say Y here to assume the entropy provided by the
  410. booloader is trustworthy so it will be added to the kernel's entropy
  411. pool. Otherwise, say N here so it will be regarded as device input that
  412. only mixes the entropy pool.