Kconfig 18 KB

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  1. # SPDX-License-Identifier: GPL-2.0
  2. config TTY
  3. bool "Enable TTY" if EXPERT
  4. default y
  5. help
  6. Allows you to remove TTY support which can save space, and
  7. blocks features that require TTY from inclusion in the kernel.
  8. TTY is required for any text terminals or serial port
  9. communication. Most users should leave this enabled.
  10. if TTY
  11. config VT
  12. bool "Virtual terminal" if EXPERT
  13. depends on !UML
  14. select INPUT
  15. default y
  16. help
  17. If you say Y here, you will get support for terminal devices with
  18. display and keyboard devices. These are called "virtual" because you
  19. can run several virtual terminals (also called virtual consoles) on
  20. one physical terminal. This is rather useful, for example one
  21. virtual terminal can collect system messages and warnings, another
  22. one can be used for a text-mode user session, and a third could run
  23. an X session, all in parallel. Switching between virtual terminals
  24. is done with certain key combinations, usually Alt-<function key>.
  25. The setterm command ("man setterm") can be used to change the
  26. properties (such as colors or beeping) of a virtual terminal. The
  27. man page console_codes(4) ("man console_codes") contains the special
  28. character sequences that can be used to change those properties
  29. directly. The fonts used on virtual terminals can be changed with
  30. the setfont ("man setfont") command and the key bindings are defined
  31. with the loadkeys ("man loadkeys") command.
  32. You need at least one virtual terminal device in order to make use
  33. of your keyboard and monitor. Therefore, only people configuring an
  34. embedded system would want to say N here in order to save some
  35. memory; the only way to log into such a system is then via a serial
  36. or network connection.
  37. If unsure, say Y, or else you won't be able to do much with your new
  38. shiny Linux system :-)
  39. config CONSOLE_TRANSLATIONS
  40. depends on VT
  41. default y
  42. bool "Enable character translations in console" if EXPERT
  43. help
  44. This enables support for font mapping and Unicode translation
  45. on virtual consoles.
  46. config VT_CONSOLE
  47. bool "Support for console on virtual terminal" if EXPERT
  48. depends on VT
  49. default y
  50. help
  51. The system console is the device which receives all kernel messages
  52. and warnings and which allows logins in single user mode. If you
  53. answer Y here, a virtual terminal (the device used to interact with
  54. a physical terminal) can be used as system console. This is the most
  55. common mode of operations, so you should say Y here unless you want
  56. the kernel messages be output only to a serial port (in which case
  57. you should say Y to "Console on serial port", below).
  58. If you do say Y here, by default the currently visible virtual
  59. terminal (/dev/tty0) will be used as system console. You can change
  60. that with a kernel command line option such as "console=tty3" which
  61. would use the third virtual terminal as system console. (Try "man
  62. bootparam" or see the documentation of your boot loader (lilo or
  63. loadlin) about how to pass options to the kernel at boot time.)
  64. If unsure, say Y.
  65. config VT_CONSOLE_SLEEP
  66. def_bool y
  67. depends on VT_CONSOLE && PM_SLEEP
  68. config HW_CONSOLE
  69. bool
  70. depends on VT && !UML
  71. default y
  72. config VT_HW_CONSOLE_BINDING
  73. bool "Support for binding and unbinding console drivers"
  74. depends on HW_CONSOLE
  75. help
  76. The virtual terminal is the device that interacts with the physical
  77. terminal through console drivers. On these systems, at least one
  78. console driver is loaded. In other configurations, additional console
  79. drivers may be enabled, such as the framebuffer console. If more than
  80. 1 console driver is enabled, setting this to 'y' will allow you to
  81. select the console driver that will serve as the backend for the
  82. virtual terminals.
  83. See <file:Documentation/driver-api/console.rst> for more
  84. information. For framebuffer console users, please refer to
  85. <file:Documentation/fb/fbcon.rst>.
  86. config UNIX98_PTYS
  87. bool "Unix98 PTY support" if EXPERT
  88. default y
  89. help
  90. A pseudo terminal (PTY) is a software device consisting of two
  91. halves: a master and a slave. The slave device behaves identical to
  92. a physical terminal; the master device is used by a process to
  93. read data from and write data to the slave, thereby emulating a
  94. terminal. Typical programs for the master side are telnet servers
  95. and xterms.
  96. Linux has traditionally used the BSD-like names /dev/ptyxx for
  97. masters and /dev/ttyxx for slaves of pseudo terminals. This scheme
  98. has a number of problems. The GNU C library glibc 2.1 and later,
  99. however, supports the Unix98 naming standard: in order to acquire a
  100. pseudo terminal, a process opens /dev/ptmx; the number of the pseudo
  101. terminal is then made available to the process and the pseudo
  102. terminal slave can be accessed as /dev/pts/<number>. What was
  103. traditionally /dev/ttyp2 will then be /dev/pts/2, for example.
  104. All modern Linux systems use the Unix98 ptys. Say Y unless
  105. you're on an embedded system and want to conserve memory.
  106. config LEGACY_PTYS
  107. bool "Legacy (BSD) PTY support"
  108. default y
  109. help
  110. A pseudo terminal (PTY) is a software device consisting of two
  111. halves: a master and a slave. The slave device behaves identical to
  112. a physical terminal; the master device is used by a process to
  113. read data from and write data to the slave, thereby emulating a
  114. terminal. Typical programs for the master side are telnet servers
  115. and xterms.
  116. Linux has traditionally used the BSD-like names /dev/ptyxx
  117. for masters and /dev/ttyxx for slaves of pseudo
  118. terminals. This scheme has a number of problems, including
  119. security. This option enables these legacy devices; on most
  120. systems, it is safe to say N.
  121. config LEGACY_PTY_COUNT
  122. int "Maximum number of legacy PTY in use"
  123. depends on LEGACY_PTYS
  124. range 0 256
  125. default "256"
  126. help
  127. The maximum number of legacy PTYs that can be used at any one time.
  128. The default is 256, and should be more than enough. Embedded
  129. systems may want to reduce this to save memory.
  130. When not in use, each legacy PTY occupies 12 bytes on 32-bit
  131. architectures and 24 bytes on 64-bit architectures.
  132. config LDISC_AUTOLOAD
  133. bool "Automatically load TTY Line Disciplines"
  134. default y
  135. help
  136. Historically the kernel has always automatically loaded any
  137. line discipline that is in a kernel module when a user asks
  138. for it to be loaded with the TIOCSETD ioctl, or through other
  139. means. This is not always the best thing to do on systems
  140. where you know you will not be using some of the more
  141. "ancient" line disciplines, so prevent the kernel from doing
  142. this unless the request is coming from a process with the
  143. CAP_SYS_MODULE permissions.
  144. Say 'Y' here if you trust your userspace users to do the right
  145. thing, or if you have only provided the line disciplines that
  146. you know you will be using, or if you wish to continue to use
  147. the traditional method of on-demand loading of these modules
  148. by any user.
  149. This functionality can be changed at runtime with the
  150. dev.tty.ldisc_autoload sysctl, this configuration option will
  151. only set the default value of this functionality.
  152. source "drivers/tty/serial/Kconfig"
  153. config SERIAL_NONSTANDARD
  154. bool "Non-standard serial port support"
  155. depends on HAS_IOMEM
  156. help
  157. Say Y here if you have any non-standard serial boards -- boards
  158. which aren't supported using the standard "dumb" serial driver.
  159. This includes intelligent serial boards such as Cyclades,
  160. Digiboards, etc. These are usually used for systems that need many
  161. serial ports because they serve many terminals or dial-in
  162. connections.
  163. Note that the answer to this question won't directly affect the
  164. kernel: saying N will just cause the configurator to skip all
  165. the questions about non-standard serial boards.
  166. Most people can say N here.
  167. config ROCKETPORT
  168. tristate "Comtrol RocketPort support"
  169. depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI)
  170. help
  171. This driver supports Comtrol RocketPort and RocketModem PCI boards.
  172. These boards provide 2, 4, 8, 16, or 32 high-speed serial ports or
  173. modems. For information about the RocketPort/RocketModem boards
  174. and this driver read <file:Documentation/driver-api/serial/rocket.rst>.
  175. To compile this driver as a module, choose M here: the
  176. module will be called rocket.
  177. If you want to compile this driver into the kernel, say Y here. If
  178. you don't have a Comtrol RocketPort/RocketModem card installed, say N.
  179. config CYCLADES
  180. tristate "Cyclades async mux support"
  181. depends on SERIAL_NONSTANDARD && (PCI || ISA)
  182. select FW_LOADER
  183. help
  184. This driver supports Cyclades Z and Y multiserial boards.
  185. You would need something like this to connect more than two modems to
  186. your Linux box, for instance in order to become a dial-in server.
  187. For information about the Cyclades-Z card, read
  188. <file:Documentation/driver-api/serial/cyclades_z.rst>.
  189. To compile this driver as a module, choose M here: the
  190. module will be called cyclades.
  191. If you haven't heard about it, it's safe to say N.
  192. config CYZ_INTR
  193. bool "Cyclades-Z interrupt mode operation"
  194. depends on CYCLADES && PCI
  195. help
  196. The Cyclades-Z family of multiport cards allows 2 (two) driver op
  197. modes: polling and interrupt. In polling mode, the driver will check
  198. the status of the Cyclades-Z ports every certain amount of time
  199. (which is called polling cycle and is configurable). In interrupt
  200. mode, it will use an interrupt line (IRQ) in order to check the
  201. status of the Cyclades-Z ports. The default op mode is polling. If
  202. unsure, say N.
  203. config MOXA_INTELLIO
  204. tristate "Moxa Intellio support"
  205. depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI)
  206. select FW_LOADER
  207. help
  208. Say Y here if you have a Moxa Intellio multiport serial card.
  209. To compile this driver as a module, choose M here: the
  210. module will be called moxa.
  211. config MOXA_SMARTIO
  212. tristate "Moxa SmartIO support v. 2.0"
  213. depends on SERIAL_NONSTANDARD && (PCI || EISA || ISA)
  214. help
  215. Say Y here if you have a Moxa SmartIO multiport serial card and/or
  216. want to help develop a new version of this driver.
  217. This is upgraded (1.9.1) driver from original Moxa drivers with
  218. changes finally resulting in PCI probing.
  219. This driver can also be built as a module. The module will be called
  220. mxser. If you want to do that, say M here.
  221. config SYNCLINK
  222. tristate "Microgate SyncLink card support"
  223. depends on SERIAL_NONSTANDARD && PCI && ISA_DMA_API
  224. help
  225. Provides support for the SyncLink ISA and PCI multiprotocol serial
  226. adapters. These adapters support asynchronous and HDLC bit
  227. synchronous communication up to 10Mbps (PCI adapter).
  228. This driver can only be built as a module ( = code which can be
  229. inserted in and removed from the running kernel whenever you want).
  230. The module will be called synclink. If you want to do that, say M
  231. here.
  232. config SYNCLINKMP
  233. tristate "SyncLink Multiport support"
  234. depends on SERIAL_NONSTANDARD && PCI
  235. help
  236. Enable support for the SyncLink Multiport (2 or 4 ports)
  237. serial adapter, running asynchronous and HDLC communications up
  238. to 2.048Mbps. Each ports is independently selectable for
  239. RS-232, V.35, RS-449, RS-530, and X.21
  240. This driver may be built as a module ( = code which can be
  241. inserted in and removed from the running kernel whenever you want).
  242. The module will be called synclinkmp. If you want to do that, say M
  243. here.
  244. config SYNCLINK_GT
  245. tristate "SyncLink GT/AC support"
  246. depends on SERIAL_NONSTANDARD && PCI
  247. help
  248. Support for SyncLink GT and SyncLink AC families of
  249. synchronous and asynchronous serial adapters
  250. manufactured by Microgate Systems, Ltd. (www.microgate.com)
  251. config ISI
  252. tristate "Multi-Tech multiport card support"
  253. depends on SERIAL_NONSTANDARD && PCI
  254. select FW_LOADER
  255. help
  256. This is a driver for the Multi-Tech cards which provide several
  257. serial ports. The driver is experimental and can currently only be
  258. built as a module. The module will be called isicom.
  259. If you want to do that, choose M here.
  260. config N_HDLC
  261. tristate "HDLC line discipline support"
  262. depends on SERIAL_NONSTANDARD
  263. help
  264. Allows synchronous HDLC communications with tty device drivers that
  265. support synchronous HDLC such as the Microgate SyncLink adapter.
  266. This driver can be built as a module ( = code which can be
  267. inserted in and removed from the running kernel whenever you want).
  268. The module will be called n_hdlc. If you want to do that, say M
  269. here.
  270. config PPC_EPAPR_HV_BYTECHAN
  271. bool "ePAPR hypervisor byte channel driver"
  272. depends on PPC
  273. select EPAPR_PARAVIRT
  274. help
  275. This driver creates /dev entries for each ePAPR hypervisor byte
  276. channel, thereby allowing applications to communicate with byte
  277. channels as if they were serial ports.
  278. config PPC_EARLY_DEBUG_EHV_BC
  279. bool "Early console (udbg) support for ePAPR hypervisors"
  280. depends on PPC_EPAPR_HV_BYTECHAN=y
  281. help
  282. Select this option to enable early console (a.k.a. "udbg") support
  283. via an ePAPR byte channel. You also need to choose the byte channel
  284. handle below.
  285. config PPC_EARLY_DEBUG_EHV_BC_HANDLE
  286. int "Byte channel handle for early console (udbg)"
  287. depends on PPC_EARLY_DEBUG_EHV_BC
  288. default 0
  289. help
  290. If you want early console (udbg) output through a byte channel,
  291. specify the handle of the byte channel to use.
  292. For this to work, the byte channel driver must be compiled
  293. in-kernel, not as a module.
  294. Note that only one early console driver can be enabled, so don't
  295. enable any others if you enable this one.
  296. If the number you specify is not a valid byte channel handle, then
  297. there simply will be no early console output. This is true also
  298. if you don't boot under a hypervisor at all.
  299. config GOLDFISH_TTY
  300. tristate "Goldfish TTY Driver"
  301. depends on GOLDFISH
  302. select SERIAL_CORE
  303. select SERIAL_CORE_CONSOLE
  304. help
  305. Console and system TTY driver for the Goldfish virtual platform.
  306. config GOLDFISH_TTY_EARLY_CONSOLE
  307. bool
  308. default y if GOLDFISH_TTY=y
  309. select SERIAL_EARLYCON
  310. config N_GSM
  311. tristate "GSM MUX line discipline support (EXPERIMENTAL)"
  312. depends on NET
  313. help
  314. This line discipline provides support for the GSM MUX protocol and
  315. presents the mux as a set of 61 individual tty devices.
  316. config NOZOMI
  317. tristate "HSDPA Broadband Wireless Data Card - Globe Trotter"
  318. depends on PCI
  319. help
  320. If you have a HSDPA driver Broadband Wireless Data Card -
  321. Globe Trotter PCMCIA card, say Y here.
  322. To compile this driver as a module, choose M here, the module
  323. will be called nozomi.
  324. config MIPS_EJTAG_FDC_TTY
  325. bool "MIPS EJTAG Fast Debug Channel TTY"
  326. depends on MIPS_CDMM
  327. help
  328. This enables a TTY and console on the MIPS EJTAG Fast Debug Channels,
  329. if they are present. This can be useful when working with an EJTAG
  330. probe which supports it, to get console output and a login prompt via
  331. EJTAG without needing to connect a serial cable.
  332. TTY devices are named e.g. ttyFDC3c2 (for FDC channel 2 of the FDC on
  333. CPU3).
  334. The console can be enabled with console=fdc1 (for FDC channel 1 on all
  335. CPUs). Do not use the console unless there is a debug probe attached
  336. to drain the FDC TX FIFO.
  337. If unsure, say N.
  338. config MIPS_EJTAG_FDC_EARLYCON
  339. bool "Early FDC console"
  340. depends on MIPS_EJTAG_FDC_TTY
  341. help
  342. This registers a console on FDC channel 1 very early during boot (from
  343. MIPS arch code). This is useful for bring-up and debugging early boot
  344. issues.
  345. Do not enable unless there is a debug probe attached to drain the FDC
  346. TX FIFO.
  347. If unsure, say N.
  348. config MIPS_EJTAG_FDC_KGDB
  349. bool "Use KGDB over an FDC channel"
  350. depends on MIPS_EJTAG_FDC_TTY && KGDB
  351. default y
  352. help
  353. This enables the use of KGDB over an FDC channel, allowing KGDB to be
  354. used remotely or when a serial port isn't available.
  355. config MIPS_EJTAG_FDC_KGDB_CHAN
  356. int "KGDB FDC channel"
  357. depends on MIPS_EJTAG_FDC_KGDB
  358. range 2 15
  359. default 3
  360. help
  361. FDC channel number to use for KGDB.
  362. config NULL_TTY
  363. tristate "NULL TTY driver"
  364. help
  365. Say Y here if you want a NULL TTY which simply discards messages.
  366. This is useful to allow userspace applications which expect a console
  367. device to work without modifications even when no console is
  368. available or desired.
  369. In order to use this driver, you should redirect the console to this
  370. TTY, or boot the kernel with console=ttynull.
  371. If unsure, say N.
  372. config TRACE_ROUTER
  373. tristate "Trace data router for MIPI P1149.7 cJTAG standard"
  374. depends on TRACE_SINK
  375. help
  376. The trace router uses the Linux tty line discipline framework to
  377. route trace data coming from a tty port (say UART for example) to
  378. the trace sink line discipline driver and to another tty port (say
  379. USB). This is part of a solution for the MIPI P1149.7, compact JTAG,
  380. standard, which is for debugging mobile devices. The PTI driver in
  381. drivers/misc/pti.c defines the majority of this MIPI solution.
  382. You should select this driver if the target kernel is meant for
  383. a mobile device containing a modem. Then you will need to select
  384. "Trace data sink for MIPI P1149.7 cJTAG standard" line discipline
  385. driver.
  386. config TRACE_SINK
  387. tristate "Trace data sink for MIPI P1149.7 cJTAG standard"
  388. help
  389. The trace sink uses the Linux line discipline framework to receive
  390. trace data coming from the trace router line discipline driver
  391. to a user-defined tty port target, like USB.
  392. This is to provide a way to extract modem trace data on
  393. devices that do not have a PTI HW module, or just need modem
  394. trace data to come out of a different HW output port.
  395. This is part of a solution for the P1149.7, compact JTAG, standard.
  396. If you select this option, you need to select
  397. "Trace data router for MIPI P1149.7 cJTAG standard".
  398. config VCC
  399. tristate "Sun Virtual Console Concentrator"
  400. depends on SUN_LDOMS
  401. help
  402. Support for Sun logical domain consoles.
  403. source "drivers/tty/hvc/Kconfig"
  404. endif # TTY
  405. source "drivers/tty/serdev/Kconfig"