1# SPDX-License-Identifier: GPL-2.0 2config 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 11if TTY 12 13config VT 14 bool "Virtual terminal" if EXPERT 15 depends on !UML 16 select INPUT 17 default y 18 ---help--- 19 If you say Y here, you will get support for terminal devices with 20 display and keyboard devices. These are called "virtual" because you 21 can run several virtual terminals (also called virtual consoles) on 22 one physical terminal. This is rather useful, for example one 23 virtual terminal can collect system messages and warnings, another 24 one can be used for a text-mode user session, and a third could run 25 an X session, all in parallel. Switching between virtual terminals 26 is done with certain key combinations, usually Alt-<function key>. 27 28 The setterm command ("man setterm") can be used to change the 29 properties (such as colors or beeping) of a virtual terminal. The 30 man page console_codes(4) ("man console_codes") contains the special 31 character sequences that can be used to change those properties 32 directly. The fonts used on virtual terminals can be changed with 33 the setfont ("man setfont") command and the key bindings are defined 34 with the loadkeys ("man loadkeys") command. 35 36 You need at least one virtual terminal device in order to make use 37 of your keyboard and monitor. Therefore, only people configuring an 38 embedded system would want to say N here in order to save some 39 memory; the only way to log into such a system is then via a serial 40 or network connection. 41 42 If unsure, say Y, or else you won't be able to do much with your new 43 shiny Linux system :-) 44 45config CONSOLE_TRANSLATIONS 46 depends on VT 47 default y 48 bool "Enable character translations in console" if EXPERT 49 ---help--- 50 This enables support for font mapping and Unicode translation 51 on virtual consoles. 52 53config VT_CONSOLE 54 bool "Support for console on virtual terminal" if EXPERT 55 depends on VT 56 default y 57 ---help--- 58 The system console is the device which receives all kernel messages 59 and warnings and which allows logins in single user mode. If you 60 answer Y here, a virtual terminal (the device used to interact with 61 a physical terminal) can be used as system console. This is the most 62 common mode of operations, so you should say Y here unless you want 63 the kernel messages be output only to a serial port (in which case 64 you should say Y to "Console on serial port", below). 65 66 If you do say Y here, by default the currently visible virtual 67 terminal (/dev/tty0) will be used as system console. You can change 68 that with a kernel command line option such as "console=tty3" which 69 would use the third virtual terminal as system console. (Try "man 70 bootparam" or see the documentation of your boot loader (lilo or 71 loadlin) about how to pass options to the kernel at boot time.) 72 73 If unsure, say Y. 74 75config VT_CONSOLE_SLEEP 76 def_bool y 77 depends on VT_CONSOLE && PM_SLEEP 78 79config HW_CONSOLE 80 bool 81 depends on VT && !UML 82 default y 83 84config VT_HW_CONSOLE_BINDING 85 bool "Support for binding and unbinding console drivers" 86 depends on HW_CONSOLE 87 ---help--- 88 The virtual terminal is the device that interacts with the physical 89 terminal through console drivers. On these systems, at least one 90 console driver is loaded. In other configurations, additional console 91 drivers may be enabled, such as the framebuffer console. If more than 92 1 console driver is enabled, setting this to 'y' will allow you to 93 select the console driver that will serve as the backend for the 94 virtual terminals. 95 96 See <file:Documentation/driver-api/console.rst> for more 97 information. For framebuffer console users, please refer to 98 <file:Documentation/fb/fbcon.rst>. 99 100config UNIX98_PTYS 101 bool "Unix98 PTY support" if EXPERT 102 default y 103 ---help--- 104 A pseudo terminal (PTY) is a software device consisting of two 105 halves: a master and a slave. The slave device behaves identical to 106 a physical terminal; the master device is used by a process to 107 read data from and write data to the slave, thereby emulating a 108 terminal. Typical programs for the master side are telnet servers 109 and xterms. 110 111 Linux has traditionally used the BSD-like names /dev/ptyxx for 112 masters and /dev/ttyxx for slaves of pseudo terminals. This scheme 113 has a number of problems. The GNU C library glibc 2.1 and later, 114 however, supports the Unix98 naming standard: in order to acquire a 115 pseudo terminal, a process opens /dev/ptmx; the number of the pseudo 116 terminal is then made available to the process and the pseudo 117 terminal slave can be accessed as /dev/pts/<number>. What was 118 traditionally /dev/ttyp2 will then be /dev/pts/2, for example. 119 120 All modern Linux systems use the Unix98 ptys. Say Y unless 121 you're on an embedded system and want to conserve memory. 122 123config LEGACY_PTYS 124 bool "Legacy (BSD) PTY support" 125 default y 126 ---help--- 127 A pseudo terminal (PTY) is a software device consisting of two 128 halves: a master and a slave. The slave device behaves identical to 129 a physical terminal; the master device is used by a process to 130 read data from and write data to the slave, thereby emulating a 131 terminal. Typical programs for the master side are telnet servers 132 and xterms. 133 134 Linux has traditionally used the BSD-like names /dev/ptyxx 135 for masters and /dev/ttyxx for slaves of pseudo 136 terminals. This scheme has a number of problems, including 137 security. This option enables these legacy devices; on most 138 systems, it is safe to say N. 139 140config LEGACY_PTY_COUNT 141 int "Maximum number of legacy PTY in use" 142 depends on LEGACY_PTYS 143 range 0 256 144 default "256" 145 ---help--- 146 The maximum number of legacy PTYs that can be used at any one time. 147 The default is 256, and should be more than enough. Embedded 148 systems may want to reduce this to save memory. 149 150 When not in use, each legacy PTY occupies 12 bytes on 32-bit 151 architectures and 24 bytes on 64-bit architectures. 152 153config LDISC_AUTOLOAD 154 bool "Automatically load TTY Line Disciplines" 155 default y 156 help 157 Historically the kernel has always automatically loaded any 158 line discipline that is in a kernel module when a user asks 159 for it to be loaded with the TIOCSETD ioctl, or through other 160 means. This is not always the best thing to do on systems 161 where you know you will not be using some of the more 162 "ancient" line disciplines, so prevent the kernel from doing 163 this unless the request is coming from a process with the 164 CAP_SYS_MODULE permissions. 165 166 Say 'Y' here if you trust your userspace users to do the right 167 thing, or if you have only provided the line disciplines that 168 you know you will be using, or if you wish to continue to use 169 the traditional method of on-demand loading of these modules 170 by any user. 171 172 This functionality can be changed at runtime with the 173 dev.tty.ldisc_autoload sysctl, this configuration option will 174 only set the default value of this functionality. 175 176source "drivers/tty/serial/Kconfig" 177 178config SERIAL_NONSTANDARD 179 bool "Non-standard serial port support" 180 depends on HAS_IOMEM 181 ---help--- 182 Say Y here if you have any non-standard serial boards -- boards 183 which aren't supported using the standard "dumb" serial driver. 184 This includes intelligent serial boards such as Cyclades, 185 Digiboards, etc. These are usually used for systems that need many 186 serial ports because they serve many terminals or dial-in 187 connections. 188 189 Note that the answer to this question won't directly affect the 190 kernel: saying N will just cause the configurator to skip all 191 the questions about non-standard serial boards. 192 193 Most people can say N here. 194 195config ROCKETPORT 196 tristate "Comtrol RocketPort support" 197 depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI) 198 help 199 This driver supports Comtrol RocketPort and RocketModem PCI boards. 200 These boards provide 2, 4, 8, 16, or 32 high-speed serial ports or 201 modems. For information about the RocketPort/RocketModem boards 202 and this driver read <file:Documentation/driver-api/serial/rocket.rst>. 203 204 To compile this driver as a module, choose M here: the 205 module will be called rocket. 206 207 If you want to compile this driver into the kernel, say Y here. If 208 you don't have a Comtrol RocketPort/RocketModem card installed, say N. 209 210config CYCLADES 211 tristate "Cyclades async mux support" 212 depends on SERIAL_NONSTANDARD && (PCI || ISA) 213 select FW_LOADER 214 ---help--- 215 This driver supports Cyclades Z and Y multiserial boards. 216 You would need something like this to connect more than two modems to 217 your Linux box, for instance in order to become a dial-in server. 218 219 For information about the Cyclades-Z card, read 220 <file:Documentation/driver-api/serial/cyclades_z.rst>. 221 222 To compile this driver as a module, choose M here: the 223 module will be called cyclades. 224 225 If you haven't heard about it, it's safe to say N. 226 227config CYZ_INTR 228 bool "Cyclades-Z interrupt mode operation" 229 depends on CYCLADES && PCI 230 help 231 The Cyclades-Z family of multiport cards allows 2 (two) driver op 232 modes: polling and interrupt. In polling mode, the driver will check 233 the status of the Cyclades-Z ports every certain amount of time 234 (which is called polling cycle and is configurable). In interrupt 235 mode, it will use an interrupt line (IRQ) in order to check the 236 status of the Cyclades-Z ports. The default op mode is polling. If 237 unsure, say N. 238 239config MOXA_INTELLIO 240 tristate "Moxa Intellio support" 241 depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI) 242 select FW_LOADER 243 help 244 Say Y here if you have a Moxa Intellio multiport serial card. 245 246 To compile this driver as a module, choose M here: the 247 module will be called moxa. 248 249config MOXA_SMARTIO 250 tristate "Moxa SmartIO support v. 2.0" 251 depends on SERIAL_NONSTANDARD && (PCI || EISA || ISA) 252 help 253 Say Y here if you have a Moxa SmartIO multiport serial card and/or 254 want to help develop a new version of this driver. 255 256 This is upgraded (1.9.1) driver from original Moxa drivers with 257 changes finally resulting in PCI probing. 258 259 This driver can also be built as a module. The module will be called 260 mxser. If you want to do that, say M here. 261 262config SYNCLINK 263 tristate "Microgate SyncLink card support" 264 depends on SERIAL_NONSTANDARD && PCI && ISA_DMA_API 265 help 266 Provides support for the SyncLink ISA and PCI multiprotocol serial 267 adapters. These adapters support asynchronous and HDLC bit 268 synchronous communication up to 10Mbps (PCI adapter). 269 270 This driver can only be built as a module ( = code which can be 271 inserted in and removed from the running kernel whenever you want). 272 The module will be called synclink. If you want to do that, say M 273 here. 274 275config SYNCLINKMP 276 tristate "SyncLink Multiport support" 277 depends on SERIAL_NONSTANDARD && PCI 278 help 279 Enable support for the SyncLink Multiport (2 or 4 ports) 280 serial adapter, running asynchronous and HDLC communications up 281 to 2.048Mbps. Each ports is independently selectable for 282 RS-232, V.35, RS-449, RS-530, and X.21 283 284 This driver may be built as a module ( = code which can be 285 inserted in and removed from the running kernel whenever you want). 286 The module will be called synclinkmp. If you want to do that, say M 287 here. 288 289config SYNCLINK_GT 290 tristate "SyncLink GT/AC support" 291 depends on SERIAL_NONSTANDARD && PCI 292 help 293 Support for SyncLink GT and SyncLink AC families of 294 synchronous and asynchronous serial adapters 295 manufactured by Microgate Systems, Ltd. (www.microgate.com) 296 297config ISI 298 tristate "Multi-Tech multiport card support" 299 depends on SERIAL_NONSTANDARD && PCI 300 select FW_LOADER 301 help 302 This is a driver for the Multi-Tech cards which provide several 303 serial ports. The driver is experimental and can currently only be 304 built as a module. The module will be called isicom. 305 If you want to do that, choose M here. 306 307config N_HDLC 308 tristate "HDLC line discipline support" 309 depends on SERIAL_NONSTANDARD 310 help 311 Allows synchronous HDLC communications with tty device drivers that 312 support synchronous HDLC such as the Microgate SyncLink adapter. 313 314 This driver can be built as a module ( = code which can be 315 inserted in and removed from the running kernel whenever you want). 316 The module will be called n_hdlc. If you want to do that, say M 317 here. 318 319config PPC_EPAPR_HV_BYTECHAN 320 bool "ePAPR hypervisor byte channel driver" 321 depends on PPC 322 select EPAPR_PARAVIRT 323 help 324 This driver creates /dev entries for each ePAPR hypervisor byte 325 channel, thereby allowing applications to communicate with byte 326 channels as if they were serial ports. 327 328config PPC_EARLY_DEBUG_EHV_BC 329 bool "Early console (udbg) support for ePAPR hypervisors" 330 depends on PPC_EPAPR_HV_BYTECHAN=y 331 help 332 Select this option to enable early console (a.k.a. "udbg") support 333 via an ePAPR byte channel. You also need to choose the byte channel 334 handle below. 335 336config PPC_EARLY_DEBUG_EHV_BC_HANDLE 337 int "Byte channel handle for early console (udbg)" 338 depends on PPC_EARLY_DEBUG_EHV_BC 339 default 0 340 help 341 If you want early console (udbg) output through a byte channel, 342 specify the handle of the byte channel to use. 343 344 For this to work, the byte channel driver must be compiled 345 in-kernel, not as a module. 346 347 Note that only one early console driver can be enabled, so don't 348 enable any others if you enable this one. 349 350 If the number you specify is not a valid byte channel handle, then 351 there simply will be no early console output. This is true also 352 if you don't boot under a hypervisor at all. 353 354config GOLDFISH_TTY 355 tristate "Goldfish TTY Driver" 356 depends on GOLDFISH 357 select SERIAL_CORE 358 select SERIAL_CORE_CONSOLE 359 help 360 Console and system TTY driver for the Goldfish virtual platform. 361 362config GOLDFISH_TTY_EARLY_CONSOLE 363 bool 364 default y if GOLDFISH_TTY=y 365 select SERIAL_EARLYCON 366 367config N_GSM 368 tristate "GSM MUX line discipline support (EXPERIMENTAL)" 369 depends on NET 370 help 371 This line discipline provides support for the GSM MUX protocol and 372 presents the mux as a set of 61 individual tty devices. 373 374config NOZOMI 375 tristate "HSDPA Broadband Wireless Data Card - Globe Trotter" 376 depends on PCI 377 help 378 If you have a HSDPA driver Broadband Wireless Data Card - 379 Globe Trotter PCMCIA card, say Y here. 380 381 To compile this driver as a module, choose M here, the module 382 will be called nozomi. 383 384config MIPS_EJTAG_FDC_TTY 385 bool "MIPS EJTAG Fast Debug Channel TTY" 386 depends on MIPS_CDMM 387 help 388 This enables a TTY and console on the MIPS EJTAG Fast Debug Channels, 389 if they are present. This can be useful when working with an EJTAG 390 probe which supports it, to get console output and a login prompt via 391 EJTAG without needing to connect a serial cable. 392 393 TTY devices are named e.g. ttyFDC3c2 (for FDC channel 2 of the FDC on 394 CPU3). 395 396 The console can be enabled with console=fdc1 (for FDC channel 1 on all 397 CPUs). Do not use the console unless there is a debug probe attached 398 to drain the FDC TX FIFO. 399 400 If unsure, say N. 401 402config MIPS_EJTAG_FDC_EARLYCON 403 bool "Early FDC console" 404 depends on MIPS_EJTAG_FDC_TTY 405 help 406 This registers a console on FDC channel 1 very early during boot (from 407 MIPS arch code). This is useful for bring-up and debugging early boot 408 issues. 409 410 Do not enable unless there is a debug probe attached to drain the FDC 411 TX FIFO. 412 413 If unsure, say N. 414 415config MIPS_EJTAG_FDC_KGDB 416 bool "Use KGDB over an FDC channel" 417 depends on MIPS_EJTAG_FDC_TTY && KGDB 418 default y 419 help 420 This enables the use of KGDB over an FDC channel, allowing KGDB to be 421 used remotely or when a serial port isn't available. 422 423config MIPS_EJTAG_FDC_KGDB_CHAN 424 int "KGDB FDC channel" 425 depends on MIPS_EJTAG_FDC_KGDB 426 range 2 15 427 default 3 428 help 429 FDC channel number to use for KGDB. 430 431config NULL_TTY 432 tristate "NULL TTY driver" 433 help 434 Say Y here if you want a NULL TTY which simply discards messages. 435 436 This is useful to allow userspace applications which expect a console 437 device to work without modifications even when no console is 438 available or desired. 439 440 In order to use this driver, you should redirect the console to this 441 TTY, or boot the kernel with console=ttynull. 442 443 If unsure, say N. 444 445config TRACE_ROUTER 446 tristate "Trace data router for MIPI P1149.7 cJTAG standard" 447 depends on TRACE_SINK 448 help 449 The trace router uses the Linux tty line discipline framework to 450 route trace data coming from a tty port (say UART for example) to 451 the trace sink line discipline driver and to another tty port (say 452 USB). This is part of a solution for the MIPI P1149.7, compact JTAG, 453 standard, which is for debugging mobile devices. The PTI driver in 454 drivers/misc/pti.c defines the majority of this MIPI solution. 455 456 You should select this driver if the target kernel is meant for 457 a mobile device containing a modem. Then you will need to select 458 "Trace data sink for MIPI P1149.7 cJTAG standard" line discipline 459 driver. 460 461config TRACE_SINK 462 tristate "Trace data sink for MIPI P1149.7 cJTAG standard" 463 help 464 The trace sink uses the Linux line discipline framework to receive 465 trace data coming from the trace router line discipline driver 466 to a user-defined tty port target, like USB. 467 This is to provide a way to extract modem trace data on 468 devices that do not have a PTI HW module, or just need modem 469 trace data to come out of a different HW output port. 470 This is part of a solution for the P1149.7, compact JTAG, standard. 471 472 If you select this option, you need to select 473 "Trace data router for MIPI P1149.7 cJTAG standard". 474 475config VCC 476 tristate "Sun Virtual Console Concentrator" 477 depends on SUN_LDOMS 478 help 479 Support for Sun logical domain consoles. 480 481source "drivers/tty/hvc/Kconfig" 482 483endif # TTY 484 485source "drivers/tty/serdev/Kconfig" 486