2 # Character device configuration
5 menu "Character devices"
8 bool "Virtual terminal" if EMBEDDED
13 If you say Y here, you will get support for terminal devices with
14 display and keyboard devices. These are called "virtual" because you
15 can run several virtual terminals (also called virtual consoles) on
16 one physical terminal. This is rather useful, for example one
17 virtual terminal can collect system messages and warnings, another
18 one can be used for a text-mode user session, and a third could run
19 an X session, all in parallel. Switching between virtual terminals
20 is done with certain key combinations, usually Alt-<function key>.
22 The setterm command ("man setterm") can be used to change the
23 properties (such as colors or beeping) of a virtual terminal. The
24 man page console_codes(4) ("man console_codes") contains the special
25 character sequences that can be used to change those properties
26 directly. The fonts used on virtual terminals can be changed with
27 the setfont ("man setfont") command and the key bindings are defined
28 with the loadkeys ("man loadkeys") command.
30 You need at least one virtual terminal device in order to make use
31 of your keyboard and monitor. Therefore, only people configuring an
32 embedded system would want to say N here in order to save some
33 memory; the only way to log into such a system is then via a serial
34 or network connection.
36 If unsure, say Y, or else you won't be able to do much with your new
37 shiny Linux system :-)
39 config CONSOLE_TRANSLATIONS
42 bool "Enable character translations in console" if EMBEDDED
44 This enables support for font mapping and Unicode translation
48 bool "Support for console on virtual terminal" if EMBEDDED
52 The system console is the device which receives all kernel messages
53 and warnings and which allows logins in single user mode. If you
54 answer Y here, a virtual terminal (the device used to interact with
55 a physical terminal) can be used as system console. This is the most
56 common mode of operations, so you should say Y here unless you want
57 the kernel messages be output only to a serial port (in which case
58 you should say Y to "Console on serial port", below).
60 If you do say Y here, by default the currently visible virtual
61 terminal (/dev/tty0) will be used as system console. You can change
62 that with a kernel command line option such as "console=tty3" which
63 would use the third virtual terminal as system console. (Try "man
64 bootparam" or see the documentation of your boot loader (lilo or
65 loadlin) about how to pass options to the kernel at boot time.)
71 depends on VT && !S390 && !UML
74 config VT_HW_CONSOLE_BINDING
75 bool "Support for binding and unbinding console drivers"
79 The virtual terminal is the device that interacts with the physical
80 terminal through console drivers. On these systems, at least one
81 console driver is loaded. In other configurations, additional console
82 drivers may be enabled, such as the framebuffer console. If more than
83 1 console driver is enabled, setting this to 'y' will allow you to
84 select the console driver that will serve as the backend for the
87 See <file:Documentation/console/console.txt> for more
88 information. For framebuffer console users, please refer to
89 <file:Documentation/fb/fbcon.txt>.
92 bool "/dev/kmem virtual device support"
95 Say Y here if you want to support the /dev/kmem device. The
96 /dev/kmem device is rarely used, but can be used for certain
97 kind of kernel debugging operations.
98 When in doubt, say "N".
100 config BFIN_JTAG_COMM
101 tristate "Blackfin JTAG Communication"
104 Add support for emulating a TTY device over the Blackfin JTAG.
106 To compile this driver as a module, choose M here: the
107 module will be called bfin_jtag_comm.
109 config BFIN_JTAG_COMM_CONSOLE
110 bool "Console on Blackfin JTAG"
111 depends on BFIN_JTAG_COMM=y
113 config SERIAL_NONSTANDARD
114 bool "Non-standard serial port support"
117 Say Y here if you have any non-standard serial boards -- boards
118 which aren't supported using the standard "dumb" serial driver.
119 This includes intelligent serial boards such as Cyclades,
120 Digiboards, etc. These are usually used for systems that need many
121 serial ports because they serve many terminals or dial-in
124 Note that the answer to this question won't directly affect the
125 kernel: saying N will just cause the configurator to skip all
126 the questions about non-standard serial boards.
128 Most people can say N here.
131 tristate "Computone IntelliPort Plus serial support"
132 depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI)
134 This driver supports the entire family of Intelliport II/Plus
135 controllers with the exception of the MicroChannel controllers and
136 products previous to the Intelliport II. These are multiport cards,
137 which give you many serial ports. You would need something like this
138 to connect more than two modems to your Linux box, for instance in
139 order to become a dial-in server. If you have a card like that, say
140 Y here and read <file:Documentation/serial/computone.txt>.
142 To compile this driver as module, choose M here: the
143 module will be called ip2.
146 tristate "Comtrol RocketPort support"
147 depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI)
149 This driver supports Comtrol RocketPort and RocketModem PCI boards.
150 These boards provide 2, 4, 8, 16, or 32 high-speed serial ports or
151 modems. For information about the RocketPort/RocketModem boards
152 and this driver read <file:Documentation/serial/rocket.txt>.
154 To compile this driver as a module, choose M here: the
155 module will be called rocket.
157 If you want to compile this driver into the kernel, say Y here. If
158 you don't have a Comtrol RocketPort/RocketModem card installed, say N.
161 tristate "Cyclades async mux support"
162 depends on SERIAL_NONSTANDARD && (PCI || ISA)
165 This driver supports Cyclades Z and Y multiserial boards.
166 You would need something like this to connect more than two modems to
167 your Linux box, for instance in order to become a dial-in server.
169 For information about the Cyclades-Z card, read
170 <file:Documentation/serial/README.cycladesZ>.
172 To compile this driver as a module, choose M here: the
173 module will be called cyclades.
175 If you haven't heard about it, it's safe to say N.
178 bool "Cyclades-Z interrupt mode operation (EXPERIMENTAL)"
179 depends on EXPERIMENTAL && CYCLADES
181 The Cyclades-Z family of multiport cards allows 2 (two) driver op
182 modes: polling and interrupt. In polling mode, the driver will check
183 the status of the Cyclades-Z ports every certain amount of time
184 (which is called polling cycle and is configurable). In interrupt
185 mode, it will use an interrupt line (IRQ) in order to check the
186 status of the Cyclades-Z ports. The default op mode is polling. If
190 tristate "Digiboard Intelligent Async Support"
191 depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI)
193 This is a driver for Digi International's Xx, Xeve, and Xem series
194 of cards which provide multiple serial ports. You would need
195 something like this to connect more than two modems to your Linux
196 box, for instance in order to become a dial-in server. This driver
197 supports the original PC (ISA) boards as well as PCI, and EISA. If
198 you have a card like this, say Y here and read the file
199 <file:Documentation/serial/digiepca.txt>.
201 To compile this driver as a module, choose M here: the
202 module will be called epca.
205 tristate "Moxa Intellio support"
206 depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI)
209 Say Y here if you have a Moxa Intellio multiport serial card.
211 To compile this driver as a module, choose M here: the
212 module will be called moxa.
215 tristate "Moxa SmartIO support v. 2.0"
216 depends on SERIAL_NONSTANDARD && (PCI || EISA || ISA)
218 Say Y here if you have a Moxa SmartIO multiport serial card and/or
219 want to help develop a new version of this driver.
221 This is upgraded (1.9.1) driver from original Moxa drivers with
222 changes finally resulting in PCI probing.
224 This driver can also be built as a module. The module will be called
225 mxser. If you want to do that, say M here.
228 tristate "Multi-Tech multiport card support (EXPERIMENTAL)"
229 depends on SERIAL_NONSTANDARD && PCI
232 This is a driver for the Multi-Tech cards which provide several
233 serial ports. The driver is experimental and can currently only be
234 built as a module. The module will be called isicom.
235 If you want to do that, choose M here.
238 tristate "Microgate SyncLink card support"
239 depends on SERIAL_NONSTANDARD && PCI && ISA_DMA_API
241 Provides support for the SyncLink ISA and PCI multiprotocol serial
242 adapters. These adapters support asynchronous and HDLC bit
243 synchronous communication up to 10Mbps (PCI adapter).
245 This driver can only be built as a module ( = code which can be
246 inserted in and removed from the running kernel whenever you want).
247 The module will be called synclink. If you want to do that, say M
251 tristate "SyncLink Multiport support"
252 depends on SERIAL_NONSTANDARD && PCI
254 Enable support for the SyncLink Multiport (2 or 4 ports)
255 serial adapter, running asynchronous and HDLC communications up
256 to 2.048Mbps. Each ports is independently selectable for
257 RS-232, V.35, RS-449, RS-530, and X.21
259 This driver may be built as a module ( = code which can be
260 inserted in and removed from the running kernel whenever you want).
261 The module will be called synclinkmp. If you want to do that, say M
265 tristate "SyncLink GT/AC support"
266 depends on SERIAL_NONSTANDARD && PCI
268 Support for SyncLink GT and SyncLink AC families of
269 synchronous and asynchronous serial adapters
270 manufactured by Microgate Systems, Ltd. (www.microgate.com)
273 tristate "HDLC line discipline support"
274 depends on SERIAL_NONSTANDARD
276 Allows synchronous HDLC communications with tty device drivers that
277 support synchronous HDLC such as the Microgate SyncLink adapter.
279 This driver can be built as a module ( = code which can be
280 inserted in and removed from the running kernel whenever you want).
281 The module will be called n_hdlc. If you want to do that, say M
285 tristate "GSM MUX line discipline support (EXPERIMENTAL)"
286 depends on EXPERIMENTAL
289 This line discipline provides support for the GSM MUX protocol and
290 presents the mux as a set of 61 individual tty devices.
293 tristate "SDL RISCom/8 card support"
294 depends on SERIAL_NONSTANDARD
296 This is a driver for the SDL Communications RISCom/8 multiport card,
297 which gives you many serial ports. You would need something like
298 this to connect more than two modems to your Linux box, for instance
299 in order to become a dial-in server. If you have a card like that,
300 say Y here and read the file <file:Documentation/serial/riscom8.txt>.
302 Also it's possible to say M here and compile this driver as kernel
303 loadable module; the module will be called riscom8.
306 tristate "Specialix IO8+ card support"
307 depends on SERIAL_NONSTANDARD
309 This is a driver for the Specialix IO8+ multiport card (both the
310 ISA and the PCI version) which gives you many serial ports. You
311 would need something like this to connect more than two modems to
312 your Linux box, for instance in order to become a dial-in server.
314 If you have a card like that, say Y here and read the file
315 <file:Documentation/serial/specialix.txt>. Also it's possible to say
316 M here and compile this driver as kernel loadable module which will be
320 tristate "Specialix SX (and SI) card support"
321 depends on SERIAL_NONSTANDARD && (PCI || EISA || ISA) && BROKEN
323 This is a driver for the SX and SI multiport serial cards.
324 Please read the file <file:Documentation/serial/sx.txt> for details.
326 This driver can only be built as a module ( = code which can be
327 inserted in and removed from the running kernel whenever you want).
328 The module will be called sx. If you want to do that, say M here.
331 tristate "Specialix RIO system support"
332 depends on SERIAL_NONSTANDARD && BROKEN
334 This is a driver for the Specialix RIO, a smart serial card which
335 drives an outboard box that can support up to 128 ports. Product
336 information is at <http://www.perle.com/support/documentation.html#multiport>.
337 There are both ISA and PCI versions.
340 bool "Support really old RIO/PCI cards"
343 Older RIO PCI cards need some initialization-time configuration to
344 determine the IRQ and some control addresses. If you have a RIO and
345 this doesn't seem to work, try setting this to Y.
348 bool "Stallion multiport serial support"
349 depends on SERIAL_NONSTANDARD
351 Stallion cards give you many serial ports. You would need something
352 like this to connect more than two modems to your Linux box, for
353 instance in order to become a dial-in server. If you say Y here,
354 you will be asked for your specific card model in the next
355 questions. Make sure to read <file:Documentation/serial/stallion.txt>
356 in this case. If you have never heard about all this, it's safe to
360 tristate "Stallion EasyIO or EC8/32 support"
361 depends on STALDRV && (ISA || EISA || PCI)
363 If you have an EasyIO or EasyConnection 8/32 multiport Stallion
364 card, then this is for you; say Y. Make sure to read
365 <file:Documentation/serial/stallion.txt>.
367 To compile this driver as a module, choose M here: the
368 module will be called stallion.
371 tristate "Stallion EC8/64, ONboard, Brumby support"
372 depends on STALDRV && (ISA || EISA || PCI)
374 If you have an EasyConnection 8/64, ONboard, Brumby or Stallion
375 serial multiport card, say Y here. Make sure to read
376 <file:Documentation/serial/stallion.txt>.
378 To compile this driver as a module, choose M here: the
379 module will be called istallion.
382 tristate "HSDPA Broadband Wireless Data Card - Globe Trotter"
383 depends on PCI && EXPERIMENTAL
385 If you have a HSDPA driver Broadband Wireless Data Card -
386 Globe Trotter PCMCIA card, say Y here.
388 To compile this driver as a module, choose M here, the module
389 will be called nozomi.
392 tristate "Commodore A2232 serial support (EXPERIMENTAL)"
393 depends on EXPERIMENTAL && ZORRO && BROKEN
395 This option supports the 2232 7-port serial card shipped with the
396 Amiga 2000 and other Zorro-bus machines, dating from 1989. At
397 a max of 19,200 bps, the ports are served by a 6551 ACIA UART chip
398 each, plus a 8520 CIA, and a master 6502 CPU and buffer as well. The
399 ports were connected with 8 pin DIN connectors on the card bracket,
400 for which 8 pin to DB25 adapters were supplied. The card also had
401 jumpers internally to toggle various pinning configurations.
403 This driver can be built as a module; but then "generic_serial"
404 will also be built as a module. This has to be loaded before
405 "ser_a2232". If you want to do this, answer M here.
408 bool "SGI Altix system controller communication support"
409 depends on (IA64_SGI_SN2 || IA64_GENERIC)
411 If you have an SGI Altix and you want to enable system
412 controller communication from user space (you want this!),
413 say Y. Otherwise, say N.
416 bool "SGI TIO CX driver support"
417 depends on (IA64_SGI_SN2 || IA64_GENERIC)
419 If you have an SGI Altix and you have fpga devices attached
420 to your TIO, say Y here, otherwise say N.
423 tristate "SGI FPGA Core Services driver support"
426 If you have an SGI Altix with an attached SABrick
427 say Y or M here, otherwise say N.
429 source "drivers/serial/Kconfig"
432 bool "Unix98 PTY support" if EMBEDDED
435 A pseudo terminal (PTY) is a software device consisting of two
436 halves: a master and a slave. The slave device behaves identical to
437 a physical terminal; the master device is used by a process to
438 read data from and write data to the slave, thereby emulating a
439 terminal. Typical programs for the master side are telnet servers
442 Linux has traditionally used the BSD-like names /dev/ptyxx for
443 masters and /dev/ttyxx for slaves of pseudo terminals. This scheme
444 has a number of problems. The GNU C library glibc 2.1 and later,
445 however, supports the Unix98 naming standard: in order to acquire a
446 pseudo terminal, a process opens /dev/ptmx; the number of the pseudo
447 terminal is then made available to the process and the pseudo
448 terminal slave can be accessed as /dev/pts/<number>. What was
449 traditionally /dev/ttyp2 will then be /dev/pts/2, for example.
451 All modern Linux systems use the Unix98 ptys. Say Y unless
452 you're on an embedded system and want to conserve memory.
454 config DEVPTS_MULTIPLE_INSTANCES
455 bool "Support multiple instances of devpts"
456 depends on UNIX98_PTYS
459 Enable support for multiple instances of devpts filesystem.
460 If you want to have isolated PTY namespaces (eg: in containers),
461 say Y here. Otherwise, say N. If enabled, each mount of devpts
462 filesystem with the '-o newinstance' option will create an
463 independent PTY namespace.
466 bool "Legacy (BSD) PTY support"
469 A pseudo terminal (PTY) is a software device consisting of two
470 halves: a master and a slave. The slave device behaves identical to
471 a physical terminal; the master device is used by a process to
472 read data from and write data to the slave, thereby emulating a
473 terminal. Typical programs for the master side are telnet servers
476 Linux has traditionally used the BSD-like names /dev/ptyxx
477 for masters and /dev/ttyxx for slaves of pseudo
478 terminals. This scheme has a number of problems, including
479 security. This option enables these legacy devices; on most
480 systems, it is safe to say N.
483 config LEGACY_PTY_COUNT
484 int "Maximum number of legacy PTY in use"
485 depends on LEGACY_PTYS
489 The maximum number of legacy PTYs that can be used at any one time.
490 The default is 256, and should be more than enough. Embedded
491 systems may want to reduce this to save memory.
493 When not in use, each legacy PTY occupies 12 bytes on 32-bit
494 architectures and 24 bytes on 64-bit architectures.
497 tristate 'Total Impact briQ front panel driver'
500 The briQ is a small footprint CHRP computer with a frontpanel VFD, a
501 tristate led and two switches. It is the size of a CDROM drive.
503 If you have such one and want anything showing on the VFD then you
506 To compile this driver as a module, choose M here: the
507 module will be called briq_panel.
509 It's safe to say N here.
512 tristate "Blackfin On-Chip OTP Memory Support"
513 depends on BLACKFIN && (BF51x || BF52x || BF54x)
516 If you say Y here, you will get support for a character device
517 interface into the One Time Programmable memory pages that are
518 stored on the Blackfin processor. This will not get you access
519 to the secure memory pages however. You will need to write your
520 own secure code and reader for that.
522 To compile this driver as a module, choose M here: the module
523 will be called bfin-otp.
525 If unsure, it is safe to say Y.
527 config BFIN_OTP_WRITE_ENABLE
528 bool "Enable writing support of OTP pages"
532 If you say Y here, you will enable support for writing of the
533 OTP pages. This is dangerous by nature as you can only program
534 the pages once, so only enable this option when you actually
535 need it so as to not inadvertently clobber data.
540 tristate "Parallel printer support"
543 If you intend to attach a printer to the parallel port of your Linux
544 box (as opposed to using a serial printer; if the connector at the
545 printer has 9 or 25 holes ["female"], then it's serial), say Y.
546 Also read the Printing-HOWTO, available from
547 <http://www.tldp.org/docs.html#howto>.
549 It is possible to share one parallel port among several devices
550 (e.g. printer and ZIP drive) and it is safe to compile the
551 corresponding drivers into the kernel.
553 To compile this driver as a module, choose M here and read
554 <file:Documentation/parport.txt>. The module will be called lp.
556 If you have several parallel ports, you can specify which ports to
557 use with the "lp" kernel command line option. (Try "man bootparam"
558 or see the documentation of your boot loader (lilo or loadlin) about
559 how to pass options to the kernel at boot time.) The syntax of the
560 "lp" command line option can be found in <file:drivers/char/lp.c>.
562 If you have more than 8 printers, you need to increase the LP_NO
563 macro in lp.c and the PARPORT_MAX macro in parport.h.
566 bool "Support for console on line printer"
569 If you want kernel messages to be printed out as they occur, you
570 can have a console on the printer. This option adds support for
571 doing that; to actually get it to happen you need to pass the
572 option "console=lp0" to the kernel at boot time.
574 If the printer is out of paper (or off, or unplugged, or too
575 busy..) the kernel will stall until the printer is ready again.
576 By defining CONSOLE_LP_STRICT to 0 (at your own risk) you
577 can make the kernel continue when this happens,
578 but it'll lose the kernel messages.
583 tristate "Support for user-space parallel port device drivers"
586 Saying Y to this adds support for /dev/parport device nodes. This
587 is needed for programs that want portable access to the parallel
588 port, for instance deviceid (which displays Plug-and-Play device
591 This is the parallel port equivalent of SCSI generic support (sg).
592 It is safe to say N to this -- it is not needed for normal printing
593 or parallel port CD-ROM/disk support.
595 To compile this driver as a module, choose M here: the
596 module will be called ppdev.
603 Generic "hypervisor virtual console" infrastructure for various
604 hypervisors (pSeries, iSeries, Xen, lguest).
605 It will automatically be selected if one of the back-end console drivers
612 bool "pSeries Hypervisor Virtual Console support"
613 depends on PPC_PSERIES
617 pSeries machines when partitioned support a hypervisor virtual
618 console. This driver allows each pSeries partition to have a console
619 which is accessed via the HMC.
622 bool "iSeries Hypervisor Virtual Console support"
623 depends on PPC_ISERIES
629 iSeries machines support a hypervisor virtual console.
632 bool "IBM RTAS Console support"
636 IBM Console device driver which makes use of RTAS
639 bool "Toshiba's Beat Hypervisor Console support"
640 depends on PPC_CELLEB
643 Toshiba's Cell Reference Set Beat Console device driver
646 bool "z/VM IUCV Hypervisor console support (VM only)"
652 This driver provides a Hypervisor console (HVC) back-end to access
653 a Linux (console) terminal via a z/VM IUCV communication path.
656 bool "Xen Hypervisor Console support"
662 Xen virtual console device driver
665 bool "udbg based fake hypervisor console"
666 depends on PPC && EXPERIMENTAL
670 config VIRTIO_CONSOLE
671 tristate "Virtio console"
675 Virtio console for use with lguest and other hypervisors.
677 Also serves as a general-purpose serial device for data
678 transfer between the guest and host. Character devices at
679 /dev/vportNpn will be created when corresponding ports are
680 found, where N is the device number and n is the port number
681 within that device. If specified by the host, a sysfs
682 attribute called 'name' will be populated with a name for
683 the port which can be used by udev scripts to create a
684 symlink to the device.
687 tristate "IBM Hypervisor Virtual Console Server support"
688 depends on PPC_PSERIES && HVC_CONSOLE
690 Partitionable IBM Power5 ppc64 machines allow hosting of
691 firmware virtual consoles from one Linux partition by
692 another Linux partition. This driver allows console data
693 from Linux partitions to be accessed through TTY device
694 interfaces in the device tree of a Linux partition running
697 To compile this driver as a module, choose M here: the
698 module will be called hvcs. Additionally, this module
699 will depend on arch specific APIs exported from hvcserver.ko
700 which will also be compiled when this driver is built as a
704 tristate "IBM POWER Barrier Synchronization Register support"
705 depends on PPC_PSERIES
707 This devices exposes a hardware mechanism for fast synchronization
708 of threads across a large system which avoids bouncing a cacheline
709 between several cores on a system
711 source "drivers/char/ipmi/Kconfig"
714 tristate "NetWinder thermometer support"
715 depends on ARCH_NETWINDER
717 Say Y here to include support for the thermal management hardware
718 found in the NetWinder. This driver allows the user to control the
719 temperature set points and to read the current temperature.
721 It is also possible to say M here to build it as a module (ds1620)
722 It is recommended to be used on a NetWinder, but it is not a
726 tristate "NetWinder Button"
727 depends on ARCH_NETWINDER
729 If you say Y here and create a character device node /dev/nwbutton
730 with major and minor numbers 10 and 158 ("man mknod"), then every
731 time the orange button is pressed a number of times, the number of
732 times the button was pressed will be written to that device.
734 This is most useful for applications, as yet unwritten, which
735 perform actions based on how many times the button is pressed in a
738 Do not hold the button down for too long, as the driver does not
739 alter the behaviour of the hardware reset circuitry attached to the
740 button; it will still execute a hard reset if the button is held
741 down for longer than approximately five seconds.
743 To compile this driver as a module, choose M here: the
744 module will be called nwbutton.
746 Most people will answer Y to this question and "Reboot Using Button"
747 below to be able to initiate a system shutdown from the button.
749 config NWBUTTON_REBOOT
750 bool "Reboot Using Button"
753 If you say Y here, then you will be able to initiate a system
754 shutdown and reboot by pressing the orange button a number of times.
755 The number of presses to initiate the shutdown is two by default,
756 but this can be altered by modifying the value of NUM_PRESSES_REBOOT
757 in nwbutton.h and recompiling the driver or, if you compile the
758 driver as a module, you can specify the number of presses at load
759 time with "insmod button reboot_count=<something>".
762 tristate "NetWinder flash support"
763 depends on ARCH_NETWINDER
765 If you say Y here and create a character device /dev/flash with
766 major 10 and minor 160 you can manipulate the flash ROM containing
767 the NetWinder firmware. Be careful as accidentally overwriting the
768 flash contents can render your computer unbootable. On no account
769 allow random users access to this device. :-)
771 To compile this driver as a module, choose M here: the
772 module will be called nwflash.
774 If you're not sure, say N.
776 source "drivers/char/hw_random/Kconfig"
779 tristate "/dev/nvram support"
780 depends on ATARI || X86 || (ARM && RTC_DRV_CMOS) || GENERIC_NVRAM
782 If you say Y here and create a character special file /dev/nvram
783 with major number 10 and minor number 144 using mknod ("man mknod"),
784 you get read and write access to the extra bytes of non-volatile
785 memory in the real time clock (RTC), which is contained in every PC
786 and most Ataris. The actual number of bytes varies, depending on the
787 nvram in the system, but is usually 114 (128-14 for the RTC).
789 This memory is conventionally called "CMOS RAM" on PCs and "NVRAM"
790 on Ataris. /dev/nvram may be used to view settings there, or to
791 change them (with some utility). It could also be used to frequently
792 save a few bits of very important data that may not be lost over
793 power-off and for which writing to disk is too insecure. Note
794 however that most NVRAM space in a PC belongs to the BIOS and you
795 should NEVER idly tamper with it. See Ralf Brown's interrupt list
796 for a guide to the use of CMOS bytes by your BIOS.
798 On Atari machines, /dev/nvram is always configured and does not need
801 To compile this driver as a module, choose M here: the
802 module will be called nvram.
805 # These legacy RTC drivers just cause too many conflicts with the generic
806 # RTC framework ... let's not even try to coexist any more.
811 tristate "Enhanced Real Time Clock Support (legacy PC RTC driver)"
812 depends on !PPC && !PARISC && !IA64 && !M68K && !SPARC && !FRV \
813 && !ARM && !SUPERH && !S390 && !AVR32 && !BLACKFIN
815 If you say Y here and create a character special file /dev/rtc with
816 major number 10 and minor number 135 using mknod ("man mknod"), you
817 will get access to the real time clock (or hardware clock) built
820 Every PC has such a clock built in. It can be used to generate
821 signals from as low as 1Hz up to 8192Hz, and can also be used
822 as a 24 hour alarm. It reports status information via the file
823 /proc/driver/rtc and its behaviour is set by various ioctls on
826 If you run Linux on a multiprocessor machine and said Y to
827 "Symmetric Multi Processing" above, you should say Y here to read
828 and set the RTC in an SMP compatible fashion.
830 If you think you have a use for such a device (such as periodic data
831 sampling), then say Y here, and read <file:Documentation/rtc.txt>
834 To compile this driver as a module, choose M here: the
835 module will be called rtc.
838 tristate "Enhanced Real Time Clock Support"
839 depends on SPARC32 && PCI
841 If you say Y here and create a character special file /dev/rtc with
842 major number 10 and minor number 135 using mknod ("man mknod"), you
843 will get access to the real time clock (or hardware clock) built
846 Every PC has such a clock built in. It can be used to generate
847 signals from as low as 1Hz up to 8192Hz, and can also be used
848 as a 24 hour alarm. It reports status information via the file
849 /proc/driver/rtc and its behaviour is set by various ioctls on
852 If you think you have a use for such a device (such as periodic data
853 sampling), then say Y here, and read <file:Documentation/rtc.txt>
856 To compile this driver as a module, choose M here: the
857 module will be called js-rtc.
860 tristate "Generic /dev/rtc emulation"
861 depends on RTC!=y && !IA64 && !ARM && !M32R && !MIPS && !SPARC && !FRV && !S390 && !SUPERH && !AVR32 && !BLACKFIN
863 If you say Y here and create a character special file /dev/rtc with
864 major number 10 and minor number 135 using mknod ("man mknod"), you
865 will get access to the real time clock (or hardware clock) built
868 It reports status information via the file /proc/driver/rtc and its
869 behaviour is set by various ioctls on /dev/rtc. If you enable the
870 "extended RTC operation" below it will also provide an emulation
871 for RTC_UIE which is required by some programs and may improve
872 precision in some cases.
874 To compile this driver as a module, choose M here: the
875 module will be called genrtc.
878 bool "Extended RTC operation"
881 Provides an emulation for RTC_UIE which is required by some programs
882 and may improve precision of the generic RTC support in some cases.
885 bool "EFI Real Time Clock Services"
889 tristate "DS1302 RTC support"
890 depends on M32R && (PLAT_M32700UT || PLAT_OPSPUT)
892 If you say Y here and create a character special file /dev/rtc with
893 major number 121 and minor number 0 using mknod ("man mknod"), you
894 will get access to the real time clock (or hardware clock) built
900 tristate "Double Talk PC internal speech card support"
903 This driver is for the DoubleTalk PC, a speech synthesizer
904 manufactured by RC Systems (<http://www.rcsys.com/>). It is also
905 called the `internal DoubleTalk'.
907 To compile this driver as a module, choose M here: the
908 module will be called dtlk.
911 tristate "Xilinx HWICAP Support"
912 depends on XILINX_VIRTEX || MICROBLAZE
914 This option enables support for Xilinx Internal Configuration
915 Access Port (ICAP) driver. The ICAP is used on Xilinx Virtex
916 FPGA platforms to partially reconfigure the FPGA at runtime.
921 tristate "Siemens R3964 line discipline"
923 This driver allows synchronous communication with devices using the
924 Siemens R3964 packet protocol. Unless you are dealing with special
925 hardware like PLCs, you are unlikely to need this.
927 To compile this driver as a module, choose M here: the
928 module will be called n_r3964.
933 tristate "Applicom intelligent fieldbus card support"
936 This driver provides the kernel-side support for the intelligent
937 fieldbus cards made by Applicom International. More information
938 about these cards can be found on the WWW at the address
939 <http://www.applicom-int.com/>, or by email from David Woodhouse
940 <dwmw2@infradead.org>.
942 To compile this driver as a module, choose M here: the
943 module will be called applicom.
948 tristate "Sony Vaio Programmable I/O Control Device support (EXPERIMENTAL)"
949 depends on EXPERIMENTAL && X86 && PCI && INPUT && !64BIT
951 This driver enables access to the Sony Programmable I/O Control
952 Device which can be found in many (all ?) Sony Vaio laptops.
954 If you have one of those laptops, read
955 <file:Documentation/laptops/sonypi.txt>, and say Y or M here.
957 To compile this driver as a module, choose M here: the
958 module will be called sonypi.
961 tristate "TANBAC TB0219 GPIO support"
962 depends on TANBAC_TB022X
965 source "drivers/char/pcmcia/Kconfig"
968 tristate "ACP Modem (Mwave) support"
972 The ACP modem (Mwave) for Linux is a WinModem. It is composed of a
973 kernel driver and a user level application. Together these components
974 support direct attachment to public switched telephone networks (PSTNs)
975 and support selected world wide countries.
977 This version of the ACP Modem driver supports the IBM Thinkpad 600E,
978 600, and 770 that include on board ACP modem hardware.
980 The modem also supports the standard communications port interface
981 (ttySx) and is compatible with the Hayes AT Command Set.
983 The user level application needed to use this driver can be found at
984 the IBM Linux Technology Center (LTC) web site:
985 <http://www.ibm.com/linux/ltc/>.
987 If you own one of the above IBM Thinkpads which has the Mwave chipset
990 To compile this driver as a module, choose M here: the
991 module will be called mwave.
994 tristate "NatSemi SCx200 GPIO Support"
998 Give userspace access to the GPIO pins on the National
999 Semiconductor SCx200 processors.
1001 If compiled as a module, it will be called scx200_gpio.
1004 tristate "NatSemi PC8736x GPIO Support"
1006 default SCx200_GPIO # mostly N
1007 select NSC_GPIO # needed for support routines
1009 Give userspace access to the GPIO pins on the National
1010 Semiconductor PC-8736x (x=[03456]) SuperIO chip. The chip
1011 has multiple functional units, inc several managed by
1012 hwmon/pc87360 driver. Tested with PC-87366
1014 If compiled as a module, it will be called pc8736x_gpio.
1017 tristate "NatSemi Base GPIO Support"
1019 # selected by SCx200_GPIO and PC8736x_GPIO
1020 # what about 2 selectors differing: m != y
1022 Common support used (and needed) by scx200_gpio and
1023 pc8736x_gpio drivers. If those drivers are built as
1024 modules, this one will be too, named nsc_gpio
1027 tristate "AMD CS5535/CS5536 GPIO (Geode Companion Device)"
1030 Give userspace access to the GPIO pins on the AMD CS5535 and
1031 CS5536 Geode companion devices.
1033 If compiled as a module, it will be called cs5535_gpio.
1036 tristate "RAW driver (/dev/raw/rawN)"
1039 The raw driver permits block devices to be bound to /dev/raw/rawN.
1040 Once bound, I/O against /dev/raw/rawN uses efficient zero-copy I/O.
1041 See the raw(8) manpage for more details.
1043 Applications should preferably open the device (eg /dev/hda1)
1044 with the O_DIRECT flag.
1047 int "Maximum number of RAW devices to support (1-8192)"
1048 depends on RAW_DRIVER
1051 The maximum number of RAW devices that are supported.
1052 Default is 256. Increase this number in case you need lots of
1056 bool "HPET - High Precision Event Timer" if (X86 || IA64)
1060 If you say Y here, you will have a miscdevice named "/dev/hpet/". Each
1061 open selects one of the timers supported by the HPET. The timers are
1062 non-periodic and/or periodic.
1065 bool "Allow mmap of HPET"
1069 If you say Y here, user applications will be able to mmap
1072 In some hardware implementations, the page containing HPET
1073 registers may also contain other things that shouldn't be
1074 exposed to the user. If this applies to your hardware,
1077 config HANGCHECK_TIMER
1078 tristate "Hangcheck timer"
1079 depends on X86 || IA64 || PPC64 || S390
1081 The hangcheck-timer module detects when the system has gone
1082 out to lunch past a certain margin. It can reboot the system
1083 or merely print a warning.
1086 tristate "MMTIMER Memory mapped RTC for SGI Altix"
1087 depends on IA64_GENERIC || IA64_SGI_SN2
1090 The mmtimer device allows direct userspace access to the
1094 tristate "UV_MMTIMER Memory mapped RTC for SGI UV"
1098 The uv_mmtimer device allows direct userspace access to the
1101 source "drivers/char/tpm/Kconfig"
1104 tristate "Telecom clock driver for ATCA SBC"
1105 depends on EXPERIMENTAL && X86
1108 The telecom clock device is specific to the MPCBL0010 and MPCBL0050
1109 ATCA computers and allows direct userspace access to the
1110 configuration of the telecom clock configuration settings. This
1111 device is used for hardware synchronization across the ATCA backplane
1112 fabric. Upon loading, the driver exports a sysfs directory,
1113 /sys/devices/platform/telco_clock, with a number of files for
1114 controlling the behavior of this hardware.
1119 depends on ISA || PCI
1122 source "drivers/s390/char/Kconfig"
1125 tristate "Log panic/oops to a RAM buffer"
1126 depends on HAS_IOMEM
1129 This enables panic and oops messages to be logged to a circular
1130 buffer in RAM where it can be read back at some later point.