xref: /openbmc/linux/drivers/tty/Kconfig (revision be709d48)
1config TTY
2	bool "Enable TTY" if EXPERT
3	default y
4	---help---
5	  Allows you to remove TTY support which can save space, and
6	  blocks features that require TTY from inclusion in the kernel.
7	  TTY is required for any text terminals or serial port
8	  communication. Most users should leave this enabled.
9
10if TTY
11
12config VT
13	bool "Virtual terminal" if EXPERT
14	depends on !UML
15	select INPUT
16	default y
17	---help---
18	  If you say Y here, you will get support for terminal devices with
19	  display and keyboard devices. These are called "virtual" because you
20	  can run several virtual terminals (also called virtual consoles) on
21	  one physical terminal. This is rather useful, for example one
22	  virtual terminal can collect system messages and warnings, another
23	  one can be used for a text-mode user session, and a third could run
24	  an X session, all in parallel. Switching between virtual terminals
25	  is done with certain key combinations, usually Alt-<function key>.
26
27	  The setterm command ("man setterm") can be used to change the
28	  properties (such as colors or beeping) of a virtual terminal. The
29	  man page console_codes(4) ("man console_codes") contains the special
30	  character sequences that can be used to change those properties
31	  directly. The fonts used on virtual terminals can be changed with
32	  the setfont ("man setfont") command and the key bindings are defined
33	  with the loadkeys ("man loadkeys") command.
34
35	  You need at least one virtual terminal device in order to make use
36	  of your keyboard and monitor. Therefore, only people configuring an
37	  embedded system would want to say N here in order to save some
38	  memory; the only way to log into such a system is then via a serial
39	  or network connection.
40
41	  If unsure, say Y, or else you won't be able to do much with your new
42	  shiny Linux system :-)
43
44config CONSOLE_TRANSLATIONS
45	depends on VT
46	default y
47	bool "Enable character translations in console" if EXPERT
48	---help---
49	  This enables support for font mapping and Unicode translation
50	  on virtual consoles.
51
52config VT_CONSOLE
53	bool "Support for console on virtual terminal" if EXPERT
54	depends on VT
55	default y
56	---help---
57	  The system console is the device which receives all kernel messages
58	  and warnings and which allows logins in single user mode. If you
59	  answer Y here, a virtual terminal (the device used to interact with
60	  a physical terminal) can be used as system console. This is the most
61	  common mode of operations, so you should say Y here unless you want
62	  the kernel messages be output only to a serial port (in which case
63	  you should say Y to "Console on serial port", below).
64
65	  If you do say Y here, by default the currently visible virtual
66	  terminal (/dev/tty0) will be used as system console. You can change
67	  that with a kernel command line option such as "console=tty3" which
68	  would use the third virtual terminal as system console. (Try "man
69	  bootparam" or see the documentation of your boot loader (lilo or
70	  loadlin) about how to pass options to the kernel at boot time.)
71
72	  If unsure, say Y.
73
74config VT_CONSOLE_SLEEP
75	def_bool y
76	depends on VT_CONSOLE && PM_SLEEP
77
78config HW_CONSOLE
79	bool
80	depends on VT && !UML
81	default y
82
83config VT_HW_CONSOLE_BINDING
84       bool "Support for binding and unbinding console drivers"
85       depends on HW_CONSOLE
86       default n
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/console/console.txt> for more
97	 information. For framebuffer console users, please refer to
98	 <file:Documentation/fb/fbcon.txt>.
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
140
141config LEGACY_PTY_COUNT
142	int "Maximum number of legacy PTY in use"
143	depends on LEGACY_PTYS
144	range 0 256
145	default "256"
146	---help---
147	  The maximum number of legacy PTYs that can be used at any one time.
148	  The default is 256, and should be more than enough.  Embedded
149	  systems may want to reduce this to save memory.
150
151	  When not in use, each legacy PTY occupies 12 bytes on 32-bit
152	  architectures and 24 bytes on 64-bit architectures.
153
154config SERIAL_NONSTANDARD
155	bool "Non-standard serial port support"
156	depends on HAS_IOMEM
157	---help---
158	  Say Y here if you have any non-standard serial boards -- boards
159	  which aren't supported using the standard "dumb" serial driver.
160	  This includes intelligent serial boards such as Cyclades,
161	  Digiboards, etc. These are usually used for systems that need many
162	  serial ports because they serve many terminals or dial-in
163	  connections.
164
165	  Note that the answer to this question won't directly affect the
166	  kernel: saying N will just cause the configurator to skip all
167	  the questions about non-standard serial boards.
168
169	  Most people can say N here.
170
171config ROCKETPORT
172	tristate "Comtrol RocketPort support"
173	depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI)
174	help
175	  This driver supports Comtrol RocketPort and RocketModem PCI boards.
176          These boards provide 2, 4, 8, 16, or 32 high-speed serial ports or
177          modems.  For information about the RocketPort/RocketModem  boards
178          and this driver read <file:Documentation/serial/rocket.txt>.
179
180	  To compile this driver as a module, choose M here: the
181	  module will be called rocket.
182
183	  If you want to compile this driver into the kernel, say Y here.  If
184          you don't have a Comtrol RocketPort/RocketModem card installed, say N.
185
186config CYCLADES
187	tristate "Cyclades async mux support"
188	depends on SERIAL_NONSTANDARD && (PCI || ISA)
189	select FW_LOADER
190	---help---
191	  This driver supports Cyclades Z and Y multiserial boards.
192	  You would need something like this to connect more than two modems to
193	  your Linux box, for instance in order to become a dial-in server.
194
195	  For information about the Cyclades-Z card, read
196	  <file:Documentation/serial/README.cycladesZ>.
197
198	  To compile this driver as a module, choose M here: the
199	  module will be called cyclades.
200
201	  If you haven't heard about it, it's safe to say N.
202
203config CYZ_INTR
204	bool "Cyclades-Z interrupt mode operation"
205	depends on CYCLADES && PCI
206	help
207	  The Cyclades-Z family of multiport cards allows 2 (two) driver op
208	  modes: polling and interrupt. In polling mode, the driver will check
209	  the status of the Cyclades-Z ports every certain amount of time
210	  (which is called polling cycle and is configurable). In interrupt
211	  mode, it will use an interrupt line (IRQ) in order to check the
212	  status of the Cyclades-Z ports. The default op mode is polling. If
213	  unsure, say N.
214
215config MOXA_INTELLIO
216	tristate "Moxa Intellio support"
217	depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI)
218	select FW_LOADER
219	help
220	  Say Y here if you have a Moxa Intellio multiport serial card.
221
222	  To compile this driver as a module, choose M here: the
223	  module will be called moxa.
224
225config MOXA_SMARTIO
226	tristate "Moxa SmartIO support v. 2.0"
227	depends on SERIAL_NONSTANDARD && (PCI || EISA || ISA)
228	help
229	  Say Y here if you have a Moxa SmartIO multiport serial card and/or
230	  want to help develop a new version of this driver.
231
232	  This is upgraded (1.9.1) driver from original Moxa drivers with
233	  changes finally resulting in PCI probing.
234
235	  This driver can also be built as a module. The module will be called
236	  mxser. If you want to do that, say M here.
237
238config SYNCLINK
239	tristate "Microgate SyncLink card support"
240	depends on SERIAL_NONSTANDARD && PCI && ISA_DMA_API
241	help
242	  Provides support for the SyncLink ISA and PCI multiprotocol serial
243	  adapters. These adapters support asynchronous and HDLC bit
244	  synchronous communication up to 10Mbps (PCI adapter).
245
246	  This driver can only be built as a module ( = code which can be
247	  inserted in and removed from the running kernel whenever you want).
248	  The module will be called synclink.  If you want to do that, say M
249	  here.
250
251config SYNCLINKMP
252	tristate "SyncLink Multiport support"
253	depends on SERIAL_NONSTANDARD && PCI
254	help
255	  Enable support for the SyncLink Multiport (2 or 4 ports)
256	  serial adapter, running asynchronous and HDLC communications up
257	  to 2.048Mbps. Each ports is independently selectable for
258	  RS-232, V.35, RS-449, RS-530, and X.21
259
260	  This driver may be built as a module ( = code which can be
261	  inserted in and removed from the running kernel whenever you want).
262	  The module will be called synclinkmp.  If you want to do that, say M
263	  here.
264
265config SYNCLINK_GT
266	tristate "SyncLink GT/AC support"
267	depends on SERIAL_NONSTANDARD && PCI
268	help
269	  Support for SyncLink GT and SyncLink AC families of
270	  synchronous and asynchronous serial adapters
271	  manufactured by Microgate Systems, Ltd. (www.microgate.com)
272
273config NOZOMI
274	tristate "HSDPA Broadband Wireless Data Card - Globe Trotter"
275	depends on PCI
276	help
277	  If you have a HSDPA driver Broadband Wireless Data Card -
278	  Globe Trotter PCMCIA card, say Y here.
279
280	  To compile this driver as a module, choose M here, the module
281	  will be called nozomi.
282
283config ISI
284	tristate "Multi-Tech multiport card support"
285	depends on SERIAL_NONSTANDARD && PCI
286	select FW_LOADER
287	help
288	  This is a driver for the Multi-Tech cards which provide several
289	  serial ports.  The driver is experimental and can currently only be
290	  built as a module. The module will be called isicom.
291	  If you want to do that, choose M here.
292
293config N_HDLC
294	tristate "HDLC line discipline support"
295	depends on SERIAL_NONSTANDARD
296	help
297	  Allows synchronous HDLC communications with tty device drivers that
298	  support synchronous HDLC such as the Microgate SyncLink adapter.
299
300	  This driver can be built as a module ( = code which can be
301	  inserted in and removed from the running kernel whenever you want).
302	  The module will be called n_hdlc. If you want to do that, say M
303	  here.
304
305config N_GSM
306	tristate "GSM MUX line discipline support (EXPERIMENTAL)"
307	depends on NET
308	help
309	  This line discipline provides support for the GSM MUX protocol and
310	  presents the mux as a set of 61 individual tty devices.
311
312config TRACE_ROUTER
313	tristate "Trace data router for MIPI P1149.7 cJTAG standard"
314	depends on TRACE_SINK
315	default n
316	help
317	  The trace router uses the Linux tty line discipline framework to
318	  route trace data coming from a tty port (say UART for example) to
319	  the trace sink line discipline driver and to another tty port (say
320	  USB). This is part of a solution for the MIPI P1149.7, compact JTAG,
321	  standard, which is for debugging mobile devices. The PTI driver in
322	  drivers/misc/pti.c defines the majority of this MIPI solution.
323
324	  You should select this driver if the target kernel is meant for
325	  a mobile device containing a modem.  Then you will need to select
326	  "Trace data sink for MIPI P1149.7 cJTAG standard" line discipline
327	  driver.
328
329config TRACE_SINK
330	tristate "Trace data sink for MIPI P1149.7 cJTAG standard"
331	default n
332	help
333	  The trace sink uses the Linux line discipline framework to receive
334	  trace data coming from the trace router line discipline driver
335	  to a user-defined tty port target, like USB.
336	  This is to provide a way to extract modem trace data on
337	  devices that do not have a PTI HW module, or just need modem
338	  trace data to come out of a different HW output port.
339	  This is part of a solution for the P1149.7, compact JTAG, standard.
340
341	  If you select this option, you need to select
342	  "Trace data router for MIPI P1149.7 cJTAG standard".
343
344config PPC_EPAPR_HV_BYTECHAN
345	bool "ePAPR hypervisor byte channel driver"
346	depends on PPC
347	select EPAPR_PARAVIRT
348	help
349	  This driver creates /dev entries for each ePAPR hypervisor byte
350	  channel, thereby allowing applications to communicate with byte
351	  channels as if they were serial ports.
352
353config PPC_EARLY_DEBUG_EHV_BC
354	bool "Early console (udbg) support for ePAPR hypervisors"
355	depends on PPC_EPAPR_HV_BYTECHAN=y
356	help
357	  Select this option to enable early console (a.k.a. "udbg") support
358	  via an ePAPR byte channel.  You also need to choose the byte channel
359	  handle below.
360
361config PPC_EARLY_DEBUG_EHV_BC_HANDLE
362	int "Byte channel handle for early console (udbg)"
363	depends on PPC_EARLY_DEBUG_EHV_BC
364	default 0
365	help
366	  If you want early console (udbg) output through a byte channel,
367	  specify the handle of the byte channel to use.
368
369	  For this to work, the byte channel driver must be compiled
370	  in-kernel, not as a module.
371
372	  Note that only one early console driver can be enabled, so don't
373	  enable any others if you enable this one.
374
375	  If the number you specify is not a valid byte channel handle, then
376	  there simply will be no early console output.  This is true also
377	  if you don't boot under a hypervisor at all.
378
379config GOLDFISH_TTY
380	tristate "Goldfish TTY Driver"
381	depends on GOLDFISH
382	select SERIAL_CORE
383	select SERIAL_CORE_CONSOLE
384	help
385	  Console and system TTY driver for the Goldfish virtual platform.
386
387config GOLDFISH_TTY_EARLY_CONSOLE
388	bool
389	default y if GOLDFISH_TTY=y
390	select SERIAL_EARLYCON
391
392config MIPS_EJTAG_FDC_TTY
393	bool "MIPS EJTAG Fast Debug Channel TTY"
394	depends on MIPS_CDMM
395	help
396	  This enables a TTY and console on the MIPS EJTAG Fast Debug Channels,
397	  if they are present. This can be useful when working with an EJTAG
398	  probe which supports it, to get console output and a login prompt via
399	  EJTAG without needing to connect a serial cable.
400
401	  TTY devices are named e.g. ttyFDC3c2 (for FDC channel 2 of the FDC on
402	  CPU3).
403
404	  The console can be enabled with console=fdc1 (for FDC channel 1 on all
405	  CPUs). Do not use the console unless there is a debug probe attached
406	  to drain the FDC TX FIFO.
407
408	  If unsure, say N.
409
410config MIPS_EJTAG_FDC_EARLYCON
411	bool "Early FDC console"
412	depends on MIPS_EJTAG_FDC_TTY
413	help
414	  This registers a console on FDC channel 1 very early during boot (from
415	  MIPS arch code). This is useful for bring-up and debugging early boot
416	  issues.
417
418	  Do not enable unless there is a debug probe attached to drain the FDC
419	  TX FIFO.
420
421	  If unsure, say N.
422
423config MIPS_EJTAG_FDC_KGDB
424	bool "Use KGDB over an FDC channel"
425	depends on MIPS_EJTAG_FDC_TTY && KGDB
426	default y
427	help
428          This enables the use of KGDB over an FDC channel, allowing KGDB to be
429          used remotely or when a serial port isn't available.
430
431config MIPS_EJTAG_FDC_KGDB_CHAN
432	int "KGDB FDC channel"
433	depends on MIPS_EJTAG_FDC_KGDB
434	range 2 15
435	default 3
436	help
437	  FDC channel number to use for KGDB.
438
439config VCC
440	tristate "Sun Virtual Console Concentrator"
441	depends on SUN_LDOMS
442	help
443	  Support for Sun logical domain consoles.
444
445config LDISC_AUTOLOAD
446	bool "Automatically load TTY Line Disciplines"
447	default y
448	help
449	  Historically the kernel has always automatically loaded any
450	  line discipline that is in a kernel module when a user asks
451	  for it to be loaded with the TIOCSETD ioctl, or through other
452	  means.  This is not always the best thing to do on systems
453	  where you know you will not be using some of the more
454	  "ancient" line disciplines, so prevent the kernel from doing
455	  this unless the request is coming from a process with the
456	  CAP_SYS_MODULE permissions.
457
458	  Say 'Y' here if you trust your userspace users to do the right
459	  thing, or if you have only provided the line disciplines that
460	  you know you will be using, or if you wish to continue to use
461	  the traditional method of on-demand loading of these modules
462	  by any user.
463
464	  This functionality can be changed at runtime with the
465	  dev.tty.ldisc_autoload sysctl, this configuration option will
466	  only set the default value of this functionality.
467
468endif # TTY
469