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 "Hayes ESP serial port support"
206 depends on SERIAL_NONSTANDARD && ISA && ISA_DMA_API && BROKEN
208 This is a driver which supports Hayes ESP serial ports. Both single
209 port cards and multiport cards are supported. Make sure to read
210 <file:Documentation/hayes-esp.txt>.
212 To compile this driver as a module, choose M here: the
213 module will be called esp.
218 tristate "Moxa Intellio support"
219 depends on SERIAL_NONSTANDARD && (ISA || EISA || PCI)
222 Say Y here if you have a Moxa Intellio multiport serial card.
224 To compile this driver as a module, choose M here: the
225 module will be called moxa.
228 tristate "Moxa SmartIO support v. 2.0"
229 depends on SERIAL_NONSTANDARD && (PCI || EISA || ISA)
231 Say Y here if you have a Moxa SmartIO multiport serial card and/or
232 want to help develop a new version of this driver.
234 This is upgraded (1.9.1) driver from original Moxa drivers with
235 changes finally resulting in PCI probing.
237 This driver can also be built as a module. The module will be called
238 mxser. If you want to do that, say M here.
241 tristate "Multi-Tech multiport card support (EXPERIMENTAL)"
242 depends on SERIAL_NONSTANDARD && PCI
245 This is a driver for the Multi-Tech cards which provide several
246 serial ports. The driver is experimental and can currently only be
247 built as a module. The module will be called isicom.
248 If you want to do that, choose M here.
251 tristate "Microgate SyncLink card support"
252 depends on SERIAL_NONSTANDARD && PCI && ISA_DMA_API
254 Provides support for the SyncLink ISA and PCI multiprotocol serial
255 adapters. These adapters support asynchronous and HDLC bit
256 synchronous communication up to 10Mbps (PCI adapter).
258 This driver can only be built as a module ( = code which can be
259 inserted in and removed from the running kernel whenever you want).
260 The module will be called synclink. If you want to do that, say M
264 tristate "SyncLink Multiport support"
265 depends on SERIAL_NONSTANDARD && PCI
267 Enable support for the SyncLink Multiport (2 or 4 ports)
268 serial adapter, running asynchronous and HDLC communications up
269 to 2.048Mbps. Each ports is independently selectable for
270 RS-232, V.35, RS-449, RS-530, and X.21
272 This driver may be built as a module ( = code which can be
273 inserted in and removed from the running kernel whenever you want).
274 The module will be called synclinkmp. If you want to do that, say M
278 tristate "SyncLink GT/AC support"
279 depends on SERIAL_NONSTANDARD && PCI
281 Support for SyncLink GT and SyncLink AC families of
282 synchronous and asynchronous serial adapters
283 manufactured by Microgate Systems, Ltd. (www.microgate.com)
286 tristate "HDLC line discipline support"
287 depends on SERIAL_NONSTANDARD
289 Allows synchronous HDLC communications with tty device drivers that
290 support synchronous HDLC such as the Microgate SyncLink adapter.
292 This driver can only be built as a module ( = code which can be
293 inserted in and removed from the running kernel whenever you want).
294 The module will be called n_hdlc. If you want to do that, say M
298 tristate "SDL RISCom/8 card support"
299 depends on SERIAL_NONSTANDARD
301 This is a driver for the SDL Communications RISCom/8 multiport card,
302 which gives you many serial ports. You would need something like
303 this to connect more than two modems to your Linux box, for instance
304 in order to become a dial-in server. If you have a card like that,
305 say Y here and read the file <file:Documentation/serial/riscom8.txt>.
307 Also it's possible to say M here and compile this driver as kernel
308 loadable module; the module will be called riscom8.
311 tristate "Specialix IO8+ card support"
312 depends on SERIAL_NONSTANDARD
314 This is a driver for the Specialix IO8+ multiport card (both the
315 ISA and the PCI version) which gives you many serial ports. You
316 would need something like this to connect more than two modems to
317 your Linux box, for instance in order to become a dial-in server.
319 If you have a card like that, say Y here and read the file
320 <file:Documentation/serial/specialix.txt>. Also it's possible to say
321 M here and compile this driver as kernel loadable module which will be
325 tristate "Specialix SX (and SI) card support"
326 depends on SERIAL_NONSTANDARD && (PCI || EISA || ISA)
328 This is a driver for the SX and SI multiport serial cards.
329 Please read the file <file:Documentation/serial/sx.txt> for details.
331 This driver can only be built as a module ( = code which can be
332 inserted in and removed from the running kernel whenever you want).
333 The module will be called sx. If you want to do that, say M here.
336 tristate "Specialix RIO system support"
337 depends on SERIAL_NONSTANDARD
339 This is a driver for the Specialix RIO, a smart serial card which
340 drives an outboard box that can support up to 128 ports. Product
341 information is at <http://www.perle.com/support/documentation.html#multiport>.
342 There are both ISA and PCI versions.
345 bool "Support really old RIO/PCI cards"
348 Older RIO PCI cards need some initialization-time configuration to
349 determine the IRQ and some control addresses. If you have a RIO and
350 this doesn't seem to work, try setting this to Y.
353 bool "Stallion multiport serial support"
354 depends on SERIAL_NONSTANDARD
356 Stallion cards give you many serial ports. You would need something
357 like this to connect more than two modems to your Linux box, for
358 instance in order to become a dial-in server. If you say Y here,
359 you will be asked for your specific card model in the next
360 questions. Make sure to read <file:Documentation/serial/stallion.txt>
361 in this case. If you have never heard about all this, it's safe to
365 tristate "Stallion EasyIO or EC8/32 support"
366 depends on STALDRV && (ISA || EISA || PCI)
368 If you have an EasyIO or EasyConnection 8/32 multiport Stallion
369 card, then this is for you; say Y. Make sure to read
370 <file:Documentation/serial/stallion.txt>.
372 To compile this driver as a module, choose M here: the
373 module will be called stallion.
376 tristate "Stallion EC8/64, ONboard, Brumby support"
377 depends on STALDRV && (ISA || EISA || PCI)
379 If you have an EasyConnection 8/64, ONboard, Brumby or Stallion
380 serial multiport card, say Y here. Make sure to read
381 <file:Documentation/serial/stallion.txt>.
383 To compile this driver as a module, choose M here: the
384 module will be called istallion.
387 tristate "HSDPA Broadband Wireless Data Card - Globe Trotter"
388 depends on PCI && EXPERIMENTAL
390 If you have a HSDPA driver Broadband Wireless Data Card -
391 Globe Trotter PCMCIA card, say Y here.
393 To compile this driver as a module, choose M here, the module
394 will be called nozomi.
397 tristate "Commodore A2232 serial support (EXPERIMENTAL)"
398 depends on EXPERIMENTAL && ZORRO && BROKEN_ON_SMP
400 This option supports the 2232 7-port serial card shipped with the
401 Amiga 2000 and other Zorro-bus machines, dating from 1989. At
402 a max of 19,200 bps, the ports are served by a 6551 ACIA UART chip
403 each, plus a 8520 CIA, and a master 6502 CPU and buffer as well. The
404 ports were connected with 8 pin DIN connectors on the card bracket,
405 for which 8 pin to DB25 adapters were supplied. The card also had
406 jumpers internally to toggle various pinning configurations.
408 This driver can be built as a module; but then "generic_serial"
409 will also be built as a module. This has to be loaded before
410 "ser_a2232". If you want to do this, answer M here.
413 bool "SGI Altix system controller communication support"
414 depends on (IA64_SGI_SN2 || IA64_GENERIC)
416 If you have an SGI Altix and you want to enable system
417 controller communication from user space (you want this!),
418 say Y. Otherwise, say N.
421 bool "SGI TIO CX driver support"
422 depends on (IA64_SGI_SN2 || IA64_GENERIC)
424 If you have an SGI Altix and you have fpga devices attached
425 to your TIO, say Y here, otherwise say N.
428 tristate "SGI FPGA Core Services driver support"
431 If you have an SGI Altix with an attached SABrick
432 say Y or M here, otherwise say N.
434 source "drivers/serial/Kconfig"
437 bool "Unix98 PTY support" if EMBEDDED
440 A pseudo terminal (PTY) is a software device consisting of two
441 halves: a master and a slave. The slave device behaves identical to
442 a physical terminal; the master device is used by a process to
443 read data from and write data to the slave, thereby emulating a
444 terminal. Typical programs for the master side are telnet servers
447 Linux has traditionally used the BSD-like names /dev/ptyxx for
448 masters and /dev/ttyxx for slaves of pseudo terminals. This scheme
449 has a number of problems. The GNU C library glibc 2.1 and later,
450 however, supports the Unix98 naming standard: in order to acquire a
451 pseudo terminal, a process opens /dev/ptmx; the number of the pseudo
452 terminal is then made available to the process and the pseudo
453 terminal slave can be accessed as /dev/pts/<number>. What was
454 traditionally /dev/ttyp2 will then be /dev/pts/2, for example.
456 All modern Linux systems use the Unix98 ptys. Say Y unless
457 you're on an embedded system and want to conserve memory.
459 config DEVPTS_MULTIPLE_INSTANCES
460 bool "Support multiple instances of devpts"
461 depends on UNIX98_PTYS
464 Enable support for multiple instances of devpts filesystem.
465 If you want to have isolated PTY namespaces (eg: in containers),
466 say Y here. Otherwise, say N. If enabled, each mount of devpts
467 filesystem with the '-o newinstance' option will create an
468 independent PTY namespace.
471 bool "Legacy (BSD) PTY support"
474 A pseudo terminal (PTY) is a software device consisting of two
475 halves: a master and a slave. The slave device behaves identical to
476 a physical terminal; the master device is used by a process to
477 read data from and write data to the slave, thereby emulating a
478 terminal. Typical programs for the master side are telnet servers
481 Linux has traditionally used the BSD-like names /dev/ptyxx
482 for masters and /dev/ttyxx for slaves of pseudo
483 terminals. This scheme has a number of problems, including
484 security. This option enables these legacy devices; on most
485 systems, it is safe to say N.
488 config LEGACY_PTY_COUNT
489 int "Maximum number of legacy PTY in use"
490 depends on LEGACY_PTYS
494 The maximum number of legacy PTYs that can be used at any one time.
495 The default is 256, and should be more than enough. Embedded
496 systems may want to reduce this to save memory.
498 When not in use, each legacy PTY occupies 12 bytes on 32-bit
499 architectures and 24 bytes on 64-bit architectures.
502 tristate 'Total Impact briQ front panel driver'
505 The briQ is a small footprint CHRP computer with a frontpanel VFD, a
506 tristate led and two switches. It is the size of a CDROM drive.
508 If you have such one and want anything showing on the VFD then you
511 To compile this driver as a module, choose M here: the
512 module will be called briq_panel.
514 It's safe to say N here.
517 tristate "Blackfin On-Chip OTP Memory Support"
518 depends on BLACKFIN && (BF52x || BF54x)
521 If you say Y here, you will get support for a character device
522 interface into the One Time Programmable memory pages that are
523 stored on the Blackfin processor. This will not get you access
524 to the secure memory pages however. You will need to write your
525 own secure code and reader for that.
527 To compile this driver as a module, choose M here: the module
528 will be called bfin-otp.
530 If unsure, it is safe to say Y.
532 config BFIN_OTP_WRITE_ENABLE
533 bool "Enable writing support of OTP pages"
537 If you say Y here, you will enable support for writing of the
538 OTP pages. This is dangerous by nature as you can only program
539 the pages once, so only enable this option when you actually
540 need it so as to not inadvertently clobber data.
545 tristate "Parallel printer support"
548 If you intend to attach a printer to the parallel port of your Linux
549 box (as opposed to using a serial printer; if the connector at the
550 printer has 9 or 25 holes ["female"], then it's serial), say Y.
551 Also read the Printing-HOWTO, available from
552 <http://www.tldp.org/docs.html#howto>.
554 It is possible to share one parallel port among several devices
555 (e.g. printer and ZIP drive) and it is safe to compile the
556 corresponding drivers into the kernel.
558 To compile this driver as a module, choose M here and read
559 <file:Documentation/parport.txt>. The module will be called lp.
561 If you have several parallel ports, you can specify which ports to
562 use with the "lp" kernel command line option. (Try "man bootparam"
563 or see the documentation of your boot loader (lilo or loadlin) about
564 how to pass options to the kernel at boot time.) The syntax of the
565 "lp" command line option can be found in <file:drivers/char/lp.c>.
567 If you have more than 8 printers, you need to increase the LP_NO
568 macro in lp.c and the PARPORT_MAX macro in parport.h.
571 bool "Support for console on line printer"
574 If you want kernel messages to be printed out as they occur, you
575 can have a console on the printer. This option adds support for
576 doing that; to actually get it to happen you need to pass the
577 option "console=lp0" to the kernel at boot time.
579 If the printer is out of paper (or off, or unplugged, or too
580 busy..) the kernel will stall until the printer is ready again.
581 By defining CONSOLE_LP_STRICT to 0 (at your own risk) you
582 can make the kernel continue when this happens,
583 but it'll lose the kernel messages.
588 tristate "Support for user-space parallel port device drivers"
591 Saying Y to this adds support for /dev/parport device nodes. This
592 is needed for programs that want portable access to the parallel
593 port, for instance deviceid (which displays Plug-and-Play device
596 This is the parallel port equivalent of SCSI generic support (sg).
597 It is safe to say N to this -- it is not needed for normal printing
598 or parallel port CD-ROM/disk support.
600 To compile this driver as a module, choose M here: the
601 module will be called ppdev.
608 Generic "hypervisor virtual console" infrastructure for various
609 hypervisors (pSeries, iSeries, Xen, lguest).
610 It will automatically be selected if one of the back-end console drivers
617 bool "pSeries Hypervisor Virtual Console support"
618 depends on PPC_PSERIES
622 pSeries machines when partitioned support a hypervisor virtual
623 console. This driver allows each pSeries partition to have a console
624 which is accessed via the HMC.
627 bool "iSeries Hypervisor Virtual Console support"
628 depends on PPC_ISERIES
634 iSeries machines support a hypervisor virtual console.
637 bool "IBM RTAS Console support"
641 IBM Console device driver which makes use of RTAS
644 bool "Toshiba's Beat Hypervisor Console support"
645 depends on PPC_CELLEB
648 Toshiba's Cell Reference Set Beat Console device driver
651 bool "z/VM IUCV Hypervisor console support (VM only)"
657 This driver provides a Hypervisor console (HVC) back-end to access
658 a Linux (console) terminal via a z/VM IUCV communication path.
661 bool "Xen Hypervisor Console support"
667 Xen virtual console device driver
670 bool "udbg based fake hypervisor console"
671 depends on PPC && EXPERIMENTAL
675 config VIRTIO_CONSOLE
676 tristate "Virtio console"
680 Virtio console for use with lguest and other hypervisors.
684 tristate "IBM Hypervisor Virtual Console Server support"
685 depends on PPC_PSERIES
687 Partitionable IBM Power5 ppc64 machines allow hosting of
688 firmware virtual consoles from one Linux partition by
689 another Linux partition. This driver allows console data
690 from Linux partitions to be accessed through TTY device
691 interfaces in the device tree of a Linux partition running
694 To compile this driver as a module, choose M here: the
695 module will be called hvcs. Additionally, this module
696 will depend on arch specific APIs exported from hvcserver.ko
697 which will also be compiled when this driver is built as a
701 tristate "IBM POWER Barrier Synchronization Register support"
702 depends on PPC_PSERIES
704 This devices exposes a hardware mechanism for fast synchronization
705 of threads across a large system which avoids bouncing a cacheline
706 between several cores on a system
708 source "drivers/char/ipmi/Kconfig"
711 tristate "NetWinder thermometer support"
712 depends on ARCH_NETWINDER
714 Say Y here to include support for the thermal management hardware
715 found in the NetWinder. This driver allows the user to control the
716 temperature set points and to read the current temperature.
718 It is also possible to say M here to build it as a module (ds1620)
719 It is recommended to be used on a NetWinder, but it is not a
723 tristate "NetWinder Button"
724 depends on ARCH_NETWINDER
726 If you say Y here and create a character device node /dev/nwbutton
727 with major and minor numbers 10 and 158 ("man mknod"), then every
728 time the orange button is pressed a number of times, the number of
729 times the button was pressed will be written to that device.
731 This is most useful for applications, as yet unwritten, which
732 perform actions based on how many times the button is pressed in a
735 Do not hold the button down for too long, as the driver does not
736 alter the behaviour of the hardware reset circuitry attached to the
737 button; it will still execute a hard reset if the button is held
738 down for longer than approximately five seconds.
740 To compile this driver as a module, choose M here: the
741 module will be called nwbutton.
743 Most people will answer Y to this question and "Reboot Using Button"
744 below to be able to initiate a system shutdown from the button.
746 config NWBUTTON_REBOOT
747 bool "Reboot Using Button"
750 If you say Y here, then you will be able to initiate a system
751 shutdown and reboot by pressing the orange button a number of times.
752 The number of presses to initiate the shutdown is two by default,
753 but this can be altered by modifying the value of NUM_PRESSES_REBOOT
754 in nwbutton.h and recompiling the driver or, if you compile the
755 driver as a module, you can specify the number of presses at load
756 time with "insmod button reboot_count=<something>".
759 tristate "NetWinder flash support"
760 depends on ARCH_NETWINDER
762 If you say Y here and create a character device /dev/flash with
763 major 10 and minor 160 you can manipulate the flash ROM containing
764 the NetWinder firmware. Be careful as accidentally overwriting the
765 flash contents can render your computer unbootable. On no account
766 allow random users access to this device. :-)
768 To compile this driver as a module, choose M here: the
769 module will be called nwflash.
771 If you're not sure, say N.
773 source "drivers/char/hw_random/Kconfig"
776 tristate "/dev/nvram support"
777 depends on ATARI || X86 || (ARM && RTC_DRV_CMOS) || GENERIC_NVRAM
779 If you say Y here and create a character special file /dev/nvram
780 with major number 10 and minor number 144 using mknod ("man mknod"),
781 you get read and write access to the extra bytes of non-volatile
782 memory in the real time clock (RTC), which is contained in every PC
783 and most Ataris. The actual number of bytes varies, depending on the
784 nvram in the system, but is usually 114 (128-14 for the RTC).
786 This memory is conventionally called "CMOS RAM" on PCs and "NVRAM"
787 on Ataris. /dev/nvram may be used to view settings there, or to
788 change them (with some utility). It could also be used to frequently
789 save a few bits of very important data that may not be lost over
790 power-off and for which writing to disk is too insecure. Note
791 however that most NVRAM space in a PC belongs to the BIOS and you
792 should NEVER idly tamper with it. See Ralf Brown's interrupt list
793 for a guide to the use of CMOS bytes by your BIOS.
795 On Atari machines, /dev/nvram is always configured and does not need
798 To compile this driver as a module, choose M here: the
799 module will be called nvram.
802 # These legacy RTC drivers just cause too many conflicts with the generic
803 # RTC framework ... let's not even try to coexist any more.
808 tristate "Enhanced Real Time Clock Support (legacy PC RTC driver)"
809 depends on !PPC && !PARISC && !IA64 && !M68K && !SPARC && !FRV \
810 && !ARM && !SUPERH && !S390 && !AVR32 && !BLACKFIN
812 If you say Y here and create a character special file /dev/rtc with
813 major number 10 and minor number 135 using mknod ("man mknod"), you
814 will get access to the real time clock (or hardware clock) built
817 Every PC has such a clock built in. It can be used to generate
818 signals from as low as 1Hz up to 8192Hz, and can also be used
819 as a 24 hour alarm. It reports status information via the file
820 /proc/driver/rtc and its behaviour is set by various ioctls on
823 If you run Linux on a multiprocessor machine and said Y to
824 "Symmetric Multi Processing" above, you should say Y here to read
825 and set the RTC in an SMP compatible fashion.
827 If you think you have a use for such a device (such as periodic data
828 sampling), then say Y here, and read <file:Documentation/rtc.txt>
831 To compile this driver as a module, choose M here: the
832 module will be called rtc.
835 tristate "Enhanced Real Time Clock Support"
836 depends on SPARC32 && PCI
838 If you say Y here and create a character special file /dev/rtc with
839 major number 10 and minor number 135 using mknod ("man mknod"), you
840 will get access to the real time clock (or hardware clock) built
843 Every PC has such a clock built in. It can be used to generate
844 signals from as low as 1Hz up to 8192Hz, and can also be used
845 as a 24 hour alarm. It reports status information via the file
846 /proc/driver/rtc and its behaviour is set by various ioctls on
849 If you think you have a use for such a device (such as periodic data
850 sampling), then say Y here, and read <file:Documentation/rtc.txt>
853 To compile this driver as a module, choose M here: the
854 module will be called js-rtc.
857 tristate "Generic /dev/rtc emulation"
858 depends on RTC!=y && !IA64 && !ARM && !M32R && !MIPS && !SPARC && !FRV && !S390 && !SUPERH && !AVR32 && !BLACKFIN
860 If you say Y here and create a character special file /dev/rtc with
861 major number 10 and minor number 135 using mknod ("man mknod"), you
862 will get access to the real time clock (or hardware clock) built
865 It reports status information via the file /proc/driver/rtc and its
866 behaviour is set by various ioctls on /dev/rtc. If you enable the
867 "extended RTC operation" below it will also provide an emulation
868 for RTC_UIE which is required by some programs and may improve
869 precision in some cases.
871 To compile this driver as a module, choose M here: the
872 module will be called genrtc.
875 bool "Extended RTC operation"
878 Provides an emulation for RTC_UIE which is required by some programs
879 and may improve precision of the generic RTC support in some cases.
882 bool "EFI Real Time Clock Services"
886 tristate "DS1302 RTC support"
887 depends on M32R && (PLAT_M32700UT || PLAT_OPSPUT)
889 If you say Y here and create a character special file /dev/rtc with
890 major number 121 and minor number 0 using mknod ("man mknod"), you
891 will get access to the real time clock (or hardware clock) built
897 tristate "Double Talk PC internal speech card support"
900 This driver is for the DoubleTalk PC, a speech synthesizer
901 manufactured by RC Systems (<http://www.rcsys.com/>). It is also
902 called the `internal DoubleTalk'.
904 To compile this driver as a module, choose M here: the
905 module will be called dtlk.
908 tristate "Xilinx HWICAP Support"
909 depends on XILINX_VIRTEX || MICROBLAZE
911 This option enables support for Xilinx Internal Configuration
912 Access Port (ICAP) driver. The ICAP is used on Xilinx Virtex
913 FPGA platforms to partially reconfigure the FPGA at runtime.
918 tristate "Siemens R3964 line discipline"
920 This driver allows synchronous communication with devices using the
921 Siemens R3964 packet protocol. Unless you are dealing with special
922 hardware like PLCs, you are unlikely to need this.
924 To compile this driver as a module, choose M here: the
925 module will be called n_r3964.
930 tristate "Applicom intelligent fieldbus card support"
933 This driver provides the kernel-side support for the intelligent
934 fieldbus cards made by Applicom International. More information
935 about these cards can be found on the WWW at the address
936 <http://www.applicom-int.com/>, or by email from David Woodhouse
937 <dwmw2@infradead.org>.
939 To compile this driver as a module, choose M here: the
940 module will be called applicom.
945 tristate "Sony Vaio Programmable I/O Control Device support (EXPERIMENTAL)"
946 depends on EXPERIMENTAL && X86 && PCI && INPUT && !64BIT
948 This driver enables access to the Sony Programmable I/O Control
949 Device which can be found in many (all ?) Sony Vaio laptops.
951 If you have one of those laptops, read
952 <file:Documentation/laptops/sonypi.txt>, and say Y or M here.
954 To compile this driver as a module, choose M here: the
955 module will be called sonypi.
958 tristate "TANBAC TB0219 GPIO support"
959 depends on TANBAC_TB022X
962 source "drivers/char/pcmcia/Kconfig"
965 tristate "ACP Modem (Mwave) support"
969 The ACP modem (Mwave) for Linux is a WinModem. It is composed of a
970 kernel driver and a user level application. Together these components
971 support direct attachment to public switched telephone networks (PSTNs)
972 and support selected world wide countries.
974 This version of the ACP Modem driver supports the IBM Thinkpad 600E,
975 600, and 770 that include on board ACP modem hardware.
977 The modem also supports the standard communications port interface
978 (ttySx) and is compatible with the Hayes AT Command Set.
980 The user level application needed to use this driver can be found at
981 the IBM Linux Technology Center (LTC) web site:
982 <http://www.ibm.com/linux/ltc/>.
984 If you own one of the above IBM Thinkpads which has the Mwave chipset
987 To compile this driver as a module, choose M here: the
988 module will be called mwave.
991 tristate "NatSemi SCx200 GPIO Support"
995 Give userspace access to the GPIO pins on the National
996 Semiconductor SCx200 processors.
998 If compiled as a module, it will be called scx200_gpio.
1001 tristate "NatSemi PC8736x GPIO Support"
1003 default SCx200_GPIO # mostly N
1004 select NSC_GPIO # needed for support routines
1006 Give userspace access to the GPIO pins on the National
1007 Semiconductor PC-8736x (x=[03456]) SuperIO chip. The chip
1008 has multiple functional units, inc several managed by
1009 hwmon/pc87360 driver. Tested with PC-87366
1011 If compiled as a module, it will be called pc8736x_gpio.
1014 tristate "NatSemi Base GPIO Support"
1016 # selected by SCx200_GPIO and PC8736x_GPIO
1017 # what about 2 selectors differing: m != y
1019 Common support used (and needed) by scx200_gpio and
1020 pc8736x_gpio drivers. If those drivers are built as
1021 modules, this one will be too, named nsc_gpio
1024 tristate "AMD CS5535/CS5536 GPIO (Geode Companion Device)"
1027 Give userspace access to the GPIO pins on the AMD CS5535 and
1028 CS5536 Geode companion devices.
1030 If compiled as a module, it will be called cs5535_gpio.
1033 tristate "RAW driver (/dev/raw/rawN)"
1036 The raw driver permits block devices to be bound to /dev/raw/rawN.
1037 Once bound, I/O against /dev/raw/rawN uses efficient zero-copy I/O.
1038 See the raw(8) manpage for more details.
1040 Applications should preferably open the device (eg /dev/hda1)
1041 with the O_DIRECT flag.
1044 int "Maximum number of RAW devices to support (1-8192)"
1045 depends on RAW_DRIVER
1048 The maximum number of RAW devices that are supported.
1049 Default is 256. Increase this number in case you need lots of
1053 bool "HPET - High Precision Event Timer" if (X86 || IA64)
1057 If you say Y here, you will have a miscdevice named "/dev/hpet/". Each
1058 open selects one of the timers supported by the HPET. The timers are
1059 non-periodic and/or periodic.
1062 bool "Allow mmap of HPET"
1066 If you say Y here, user applications will be able to mmap
1069 In some hardware implementations, the page containing HPET
1070 registers may also contain other things that shouldn't be
1071 exposed to the user. If this applies to your hardware,
1074 config HANGCHECK_TIMER
1075 tristate "Hangcheck timer"
1076 depends on X86 || IA64 || PPC64 || S390
1078 The hangcheck-timer module detects when the system has gone
1079 out to lunch past a certain margin. It can reboot the system
1080 or merely print a warning.
1083 tristate "MMTIMER Memory mapped RTC for SGI Altix"
1084 depends on IA64_GENERIC || IA64_SGI_SN2
1087 The mmtimer device allows direct userspace access to the
1090 source "drivers/char/tpm/Kconfig"
1093 tristate "Telecom clock driver for ATCA SBC"
1094 depends on EXPERIMENTAL && X86
1097 The telecom clock device is specific to the MPCBL0010 and MPCBL0050
1098 ATCA computers and allows direct userspace access to the
1099 configuration of the telecom clock configuration settings. This
1100 device is used for hardware synchronization across the ATCA backplane
1101 fabric. Upon loading, the driver exports a sysfs directory,
1102 /sys/devices/platform/telco_clock, with a number of files for
1103 controlling the behavior of this hardware.
1108 depends on ISA || PCI
1111 source "drivers/s390/char/Kconfig"
projects / linux-2.6 / blob