2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
6 mainmenu "Linux Kernel Configuration"
12 This is Linux's home port. Linux was originally native to the Intel
13 386, and runs on all the later x86 processors including the Intel
14 486, 586, Pentiums, and various instruction-set-compatible chips by
15 AMD, Cyrix, and others.
17 config SEMAPHORE_SLEEPERS
36 config GENERIC_ISA_DMA
44 config ARCH_MAY_HAVE_PC_FDC
50 menu "Processor type and features"
53 prompt "Subarchitecture Type"
59 Choose this option if your computer is a standard PC or compatible.
64 Select this for an AMD Elan processor.
66 Do not use this option for K6/Athlon/Opteron processors!
68 If unsure, choose "PC-compatible" instead.
73 Voyager is an MCA-based 32-way capable SMP architecture proprietary
74 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
78 If you do not specifically know you have a Voyager based machine,
79 say N here, otherwise the kernel you build will not be bootable.
82 bool "NUMAQ (IBM/Sequent)"
85 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
86 multiquad box. This changes the way that processors are bootstrapped,
87 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
88 You will need a new lynxer.elf file to flash your firmware with - send
89 email to <Martin.Bligh@us.ibm.com>.
92 bool "Summit/EXA (IBM x440)"
95 This option is needed for IBM systems that use the Summit/EXA chipset.
96 In particular, it is needed for the x440.
98 If you don't have one of these computers, you should say N here.
101 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
104 This option is needed for the systems that have more than 8 CPUs
105 and if the system is not of any sub-arch type above.
107 If you don't have such a system, you should say N here.
110 bool "SGI 320/540 (Visual Workstation)"
112 The SGI Visual Workstation series is an IA32-based workstation
113 based on SGI systems chips with some legacy PC hardware attached.
115 Say Y here to create a kernel to run on the SGI 320 or 540.
117 A kernel compiled for the Visual Workstation will not run on PCs
118 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
120 config X86_GENERICARCH
121 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
124 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
125 It is intended for a generic binary kernel.
128 bool "Support for Unisys ES7000 IA32 series"
131 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
132 supposed to run on an IA32-based Unisys ES7000 system.
133 Only choose this option if you have such a system, otherwise you
141 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
143 config X86_SUMMIT_NUMA
146 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
148 config X86_CYCLONE_TIMER
151 depends on X86_SUMMIT || X86_GENERICARCH
153 config ES7000_CLUSTERED_APIC
156 depends on SMP && X86_ES7000 && MPENTIUMIII
158 source "arch/i386/Kconfig.cpu"
161 bool "HPET Timer Support"
163 This enables the use of the HPET for the kernel's internal timer.
164 HPET is the next generation timer replacing legacy 8254s.
165 You can safely choose Y here. However, HPET will only be
166 activated if the platform and the BIOS support this feature.
167 Otherwise the 8254 will be used for timing services.
169 Choose N to continue using the legacy 8254 timer.
171 config HPET_EMULATE_RTC
173 depends on HPET_TIMER && RTC=y
177 bool "Symmetric multi-processing support"
179 This enables support for systems with more than one CPU. If you have
180 a system with only one CPU, like most personal computers, say N. If
181 you have a system with more than one CPU, say Y.
183 If you say N here, the kernel will run on single and multiprocessor
184 machines, but will use only one CPU of a multiprocessor machine. If
185 you say Y here, the kernel will run on many, but not all,
186 singleprocessor machines. On a singleprocessor machine, the kernel
187 will run faster if you say N here.
189 Note that if you say Y here and choose architecture "586" or
190 "Pentium" under "Processor family", the kernel will not work on 486
191 architectures. Similarly, multiprocessor kernels for the "PPro"
192 architecture may not work on all Pentium based boards.
194 People using multiprocessor machines who say Y here should also say
195 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
196 Management" code will be disabled if you say Y here.
198 See also the <file:Documentation/smp.txt>,
199 <file:Documentation/i386/IO-APIC.txt>,
200 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
201 <http://www.tldp.org/docs.html#howto>.
203 If you don't know what to do here, say N.
206 int "Maximum number of CPUs (2-255)"
209 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
212 This allows you to specify the maximum number of CPUs which this
213 kernel will support. The maximum supported value is 255 and the
214 minimum value which makes sense is 2.
216 This is purely to save memory - each supported CPU adds
217 approximately eight kilobytes to the kernel image.
220 bool "SMT (Hyperthreading) scheduler support"
224 SMT scheduler support improves the CPU scheduler's decision making
225 when dealing with Intel Pentium 4 chips with HyperThreading at a
226 cost of slightly increased overhead in some places. If unsure say
229 source "kernel/Kconfig.preempt"
232 bool "Local APIC support on uniprocessors"
233 depends on !SMP && !(X86_VISWS || X86_VOYAGER)
235 A local APIC (Advanced Programmable Interrupt Controller) is an
236 integrated interrupt controller in the CPU. If you have a single-CPU
237 system which has a processor with a local APIC, you can say Y here to
238 enable and use it. If you say Y here even though your machine doesn't
239 have a local APIC, then the kernel will still run with no slowdown at
240 all. The local APIC supports CPU-generated self-interrupts (timer,
241 performance counters), and the NMI watchdog which detects hard
245 bool "IO-APIC support on uniprocessors"
246 depends on X86_UP_APIC
248 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
249 SMP-capable replacement for PC-style interrupt controllers. Most
250 SMP systems and many recent uniprocessor systems have one.
252 If you have a single-CPU system with an IO-APIC, you can say Y here
253 to use it. If you say Y here even though your machine doesn't have
254 an IO-APIC, then the kernel will still run with no slowdown at all.
256 config X86_LOCAL_APIC
258 depends on X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER)
263 depends on X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER))
266 config X86_VISWS_APIC
272 bool "Machine Check Exception"
273 depends on !X86_VOYAGER
275 Machine Check Exception support allows the processor to notify the
276 kernel if it detects a problem (e.g. overheating, component failure).
277 The action the kernel takes depends on the severity of the problem,
278 ranging from a warning message on the console, to halting the machine.
279 Your processor must be a Pentium or newer to support this - check the
280 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
281 have a design flaw which leads to false MCE events - hence MCE is
282 disabled on all P5 processors, unless explicitly enabled with "mce"
283 as a boot argument. Similarly, if MCE is built in and creates a
284 problem on some new non-standard machine, you can boot with "nomce"
285 to disable it. MCE support simply ignores non-MCE processors like
286 the 386 and 486, so nearly everyone can say Y here.
288 config X86_MCE_NONFATAL
289 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
292 Enabling this feature starts a timer that triggers every 5 seconds which
293 will look at the machine check registers to see if anything happened.
294 Non-fatal problems automatically get corrected (but still logged).
295 Disable this if you don't want to see these messages.
296 Seeing the messages this option prints out may be indicative of dying hardware,
297 or out-of-spec (ie, overclocked) hardware.
298 This option only does something on certain CPUs.
299 (AMD Athlon/Duron and Intel Pentium 4)
301 config X86_MCE_P4THERMAL
302 bool "check for P4 thermal throttling interrupt."
303 depends on X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
305 Enabling this feature will cause a message to be printed when the P4
306 enters thermal throttling.
309 tristate "Toshiba Laptop support"
311 This adds a driver to safely access the System Management Mode of
312 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
313 not work on models with a Phoenix BIOS. The System Management Mode
314 is used to set the BIOS and power saving options on Toshiba portables.
316 For information on utilities to make use of this driver see the
317 Toshiba Linux utilities web site at:
318 <http://www.buzzard.org.uk/toshiba/>.
320 Say Y if you intend to run this kernel on a Toshiba portable.
324 tristate "Dell laptop support"
326 This adds a driver to safely access the System Management Mode
327 of the CPU on the Dell Inspiron 8000. The System Management Mode
328 is used to read cpu temperature and cooling fan status and to
329 control the fans on the I8K portables.
331 This driver has been tested only on the Inspiron 8000 but it may
332 also work with other Dell laptops. You can force loading on other
333 models by passing the parameter `force=1' to the module. Use at
336 For information on utilities to make use of this driver see the
337 I8K Linux utilities web site at:
338 <http://people.debian.org/~dz/i8k/>
340 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
343 config X86_REBOOTFIXUPS
344 bool "Enable X86 board specific fixups for reboot"
348 This enables chipset and/or board specific fixups to be done
349 in order to get reboot to work correctly. This is only needed on
350 some combinations of hardware and BIOS. The symptom, for which
351 this config is intended, is when reboot ends with a stalled/hung
354 Currently, the only fixup is for the Geode GX1/CS5530A/TROM2.1.
357 Say Y if you want to enable the fixup. Currently, it's safe to
358 enable this option even if you don't need it.
362 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
364 If you say Y here and also to "/dev file system support" in the
365 'File systems' section, you will be able to update the microcode on
366 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
367 Pentium III, Pentium 4, Xeon etc. You will obviously need the
368 actual microcode binary data itself which is not shipped with the
371 For latest news and information on obtaining all the required
372 ingredients for this driver, check:
373 <http://www.urbanmyth.org/microcode/>.
375 To compile this driver as a module, choose M here: the
376 module will be called microcode.
379 tristate "/dev/cpu/*/msr - Model-specific register support"
381 This device gives privileged processes access to the x86
382 Model-Specific Registers (MSRs). It is a character device with
383 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
384 MSR accesses are directed to a specific CPU on multi-processor
388 tristate "/dev/cpu/*/cpuid - CPU information support"
390 This device gives processes access to the x86 CPUID instruction to
391 be executed on a specific processor. It is a character device
392 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
395 source "drivers/firmware/Kconfig"
398 prompt "High Memory Support"
404 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
405 However, the address space of 32-bit x86 processors is only 4
406 Gigabytes large. That means that, if you have a large amount of
407 physical memory, not all of it can be "permanently mapped" by the
408 kernel. The physical memory that's not permanently mapped is called
411 If you are compiling a kernel which will never run on a machine with
412 more than 1 Gigabyte total physical RAM, answer "off" here (default
413 choice and suitable for most users). This will result in a "3GB/1GB"
414 split: 3GB are mapped so that each process sees a 3GB virtual memory
415 space and the remaining part of the 4GB virtual memory space is used
416 by the kernel to permanently map as much physical memory as
419 If the machine has between 1 and 4 Gigabytes physical RAM, then
422 If more than 4 Gigabytes is used then answer "64GB" here. This
423 selection turns Intel PAE (Physical Address Extension) mode on.
424 PAE implements 3-level paging on IA32 processors. PAE is fully
425 supported by Linux, PAE mode is implemented on all recent Intel
426 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
427 then the kernel will not boot on CPUs that don't support PAE!
429 The actual amount of total physical memory will either be
430 auto detected or can be forced by using a kernel command line option
431 such as "mem=256M". (Try "man bootparam" or see the documentation of
432 your boot loader (lilo or loadlin) about how to pass options to the
433 kernel at boot time.)
435 If unsure, say "off".
440 Select this if you have a 32-bit processor and between 1 and 4
441 gigabytes of physical RAM.
446 Select this if you have a 32-bit processor and more than 4
447 gigabytes of physical RAM.
453 depends on HIGHMEM64G || HIGHMEM4G
458 depends on HIGHMEM64G
461 # Common NUMA Features
463 bool "Numa Memory Allocation and Scheduler Support"
464 depends on SMP && HIGHMEM64G && (X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
466 default y if (X86_NUMAQ || X86_SUMMIT)
468 # Need comments to help the hapless user trying to turn on NUMA support
469 comment "NUMA (NUMA-Q) requires SMP, 64GB highmem support"
470 depends on X86_NUMAQ && (!HIGHMEM64G || !SMP)
472 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
473 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
475 config HAVE_ARCH_BOOTMEM_NODE
480 config ARCH_HAVE_MEMORY_PRESENT
482 depends on DISCONTIGMEM
485 config NEED_NODE_MEMMAP_SIZE
487 depends on DISCONTIGMEM || SPARSEMEM
490 config HAVE_ARCH_ALLOC_REMAP
495 config ARCH_FLATMEM_ENABLE
497 depends on (ARCH_SELECT_MEMORY_MODEL && X86_PC)
499 config ARCH_DISCONTIGMEM_ENABLE
503 config ARCH_DISCONTIGMEM_DEFAULT
507 config ARCH_SPARSEMEM_ENABLE
509 depends on (NUMA || (X86_PC && EXPERIMENTAL))
510 select SPARSEMEM_STATIC
512 config ARCH_SELECT_MEMORY_MODEL
514 depends on ARCH_SPARSEMEM_ENABLE
518 config HAVE_ARCH_EARLY_PFN_TO_NID
524 bool "Allocate 3rd-level pagetables from highmem"
525 depends on HIGHMEM4G || HIGHMEM64G
527 The VM uses one page table entry for each page of physical memory.
528 For systems with a lot of RAM, this can be wasteful of precious
529 low memory. Setting this option will put user-space page table
530 entries in high memory.
532 config MATH_EMULATION
533 bool "Math emulation"
535 Linux can emulate a math coprocessor (used for floating point
536 operations) if you don't have one. 486DX and Pentium processors have
537 a math coprocessor built in, 486SX and 386 do not, unless you added
538 a 487DX or 387, respectively. (The messages during boot time can
539 give you some hints here ["man dmesg"].) Everyone needs either a
540 coprocessor or this emulation.
542 If you don't have a math coprocessor, you need to say Y here; if you
543 say Y here even though you have a coprocessor, the coprocessor will
544 be used nevertheless. (This behavior can be changed with the kernel
545 command line option "no387", which comes handy if your coprocessor
546 is broken. Try "man bootparam" or see the documentation of your boot
547 loader (lilo or loadlin) about how to pass options to the kernel at
548 boot time.) This means that it is a good idea to say Y here if you
549 intend to use this kernel on different machines.
551 More information about the internals of the Linux math coprocessor
552 emulation can be found in <file:arch/i386/math-emu/README>.
554 If you are not sure, say Y; apart from resulting in a 66 KB bigger
555 kernel, it won't hurt.
558 bool "MTRR (Memory Type Range Register) support"
560 On Intel P6 family processors (Pentium Pro, Pentium II and later)
561 the Memory Type Range Registers (MTRRs) may be used to control
562 processor access to memory ranges. This is most useful if you have
563 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
564 allows bus write transfers to be combined into a larger transfer
565 before bursting over the PCI/AGP bus. This can increase performance
566 of image write operations 2.5 times or more. Saying Y here creates a
567 /proc/mtrr file which may be used to manipulate your processor's
568 MTRRs. Typically the X server should use this.
570 This code has a reasonably generic interface so that similar
571 control registers on other processors can be easily supported
574 The Cyrix 6x86, 6x86MX and M II processors have Address Range
575 Registers (ARRs) which provide a similar functionality to MTRRs. For
576 these, the ARRs are used to emulate the MTRRs.
577 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
578 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
579 write-combining. All of these processors are supported by this code
580 and it makes sense to say Y here if you have one of them.
582 Saying Y here also fixes a problem with buggy SMP BIOSes which only
583 set the MTRRs for the boot CPU and not for the secondary CPUs. This
584 can lead to all sorts of problems, so it's good to say Y here.
586 You can safely say Y even if your machine doesn't have MTRRs, you'll
587 just add about 9 KB to your kernel.
589 See <file:Documentation/mtrr.txt> for more information.
592 bool "Boot from EFI support (EXPERIMENTAL)"
596 This enables the the kernel to boot on EFI platforms using
597 system configuration information passed to it from the firmware.
598 This also enables the kernel to use any EFI runtime services that are
599 available (such as the EFI variable services).
601 This option is only useful on systems that have EFI firmware
602 and will result in a kernel image that is ~8k larger. In addition,
603 you must use the latest ELILO loader available at
604 <http://elilo.sourceforge.net> in order to take advantage of
605 kernel initialization using EFI information (neither GRUB nor LILO know
606 anything about EFI). However, even with this option, the resultant
607 kernel should continue to boot on existing non-EFI platforms.
610 bool "Enable kernel irq balancing"
611 depends on SMP && X86_IO_APIC
614 The default yes will allow the kernel to do irq load balancing.
615 Saying no will keep the kernel from doing irq load balancing.
617 # turning this on wastes a bunch of space.
618 # Summit needs it only when NUMA is on
621 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
625 bool "Use register arguments (EXPERIMENTAL)"
626 depends on EXPERIMENTAL
629 Compile the kernel with -mregparm=3. This uses a different ABI
630 and passes the first three arguments of a function call in registers.
631 This will probably break binary only modules.
634 bool "Enable seccomp to safely compute untrusted bytecode"
638 This kernel feature is useful for number crunching applications
639 that may need to compute untrusted bytecode during their
640 execution. By using pipes or other transports made available to
641 the process as file descriptors supporting the read/write
642 syscalls, it's possible to isolate those applications in
643 their own address space using seccomp. Once seccomp is
644 enabled via /proc/<pid>/seccomp, it cannot be disabled
645 and the task is only allowed to execute a few safe syscalls
646 defined by each seccomp mode.
648 If unsure, say Y. Only embedded should say N here.
650 source kernel/Kconfig.hz
652 config PHYSICAL_START
653 hex "Physical address where the kernel is loaded" if EMBEDDED
656 This gives the physical address where the kernel is loaded.
657 Primarily used in the case of kexec on panic where the
658 fail safe kernel needs to run at a different address than
661 Don't change this unless you know what you are doing.
664 bool "kexec system call (EXPERIMENTAL)"
665 depends on EXPERIMENTAL
667 kexec is a system call that implements the ability to shutdown your
668 current kernel, and to start another kernel. It is like a reboot
669 but it is indepedent of the system firmware. And like a reboot
670 you can start any kernel with it, not just Linux.
672 The name comes from the similiarity to the exec system call.
674 It is an ongoing process to be certain the hardware in a machine
675 is properly shutdown, so do not be surprised if this code does not
676 initially work for you. It may help to enable device hotplugging
677 support. As of this writing the exact hardware interface is
678 strongly in flux, so no good recommendation can be made.
681 bool "kernel crash dumps (EXPERIMENTAL)"
683 depends on EXPERIMENTAL
686 Generate crash dump after being started by kexec.
690 menu "Power management options (ACPI, APM)"
691 depends on !X86_VOYAGER
693 source kernel/power/Kconfig
695 source "drivers/acpi/Kconfig"
697 menu "APM (Advanced Power Management) BIOS Support"
698 depends on PM && !X86_VISWS
701 tristate "APM (Advanced Power Management) BIOS support"
702 depends on PM && PM_LEGACY
704 APM is a BIOS specification for saving power using several different
705 techniques. This is mostly useful for battery powered laptops with
706 APM compliant BIOSes. If you say Y here, the system time will be
707 reset after a RESUME operation, the /proc/apm device will provide
708 battery status information, and user-space programs will receive
709 notification of APM "events" (e.g. battery status change).
711 If you select "Y" here, you can disable actual use of the APM
712 BIOS by passing the "apm=off" option to the kernel at boot time.
714 Note that the APM support is almost completely disabled for
715 machines with more than one CPU.
717 In order to use APM, you will need supporting software. For location
718 and more information, read <file:Documentation/pm.txt> and the
719 Battery Powered Linux mini-HOWTO, available from
720 <http://www.tldp.org/docs.html#howto>.
722 This driver does not spin down disk drives (see the hdparm(8)
723 manpage ("man 8 hdparm") for that), and it doesn't turn off
724 VESA-compliant "green" monitors.
726 This driver does not support the TI 4000M TravelMate and the ACER
727 486/DX4/75 because they don't have compliant BIOSes. Many "green"
728 desktop machines also don't have compliant BIOSes, and this driver
729 may cause those machines to panic during the boot phase.
731 Generally, if you don't have a battery in your machine, there isn't
732 much point in using this driver and you should say N. If you get
733 random kernel OOPSes or reboots that don't seem to be related to
734 anything, try disabling/enabling this option (or disabling/enabling
737 Some other things you should try when experiencing seemingly random,
740 1) make sure that you have enough swap space and that it is
742 2) pass the "no-hlt" option to the kernel
743 3) switch on floating point emulation in the kernel and pass
744 the "no387" option to the kernel
745 4) pass the "floppy=nodma" option to the kernel
746 5) pass the "mem=4M" option to the kernel (thereby disabling
747 all but the first 4 MB of RAM)
748 6) make sure that the CPU is not over clocked.
749 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
750 8) disable the cache from your BIOS settings
751 9) install a fan for the video card or exchange video RAM
752 10) install a better fan for the CPU
753 11) exchange RAM chips
754 12) exchange the motherboard.
756 To compile this driver as a module, choose M here: the
757 module will be called apm.
759 config APM_IGNORE_USER_SUSPEND
760 bool "Ignore USER SUSPEND"
763 This option will ignore USER SUSPEND requests. On machines with a
764 compliant APM BIOS, you want to say N. However, on the NEC Versa M
765 series notebooks, it is necessary to say Y because of a BIOS bug.
768 bool "Enable PM at boot time"
771 Enable APM features at boot time. From page 36 of the APM BIOS
772 specification: "When disabled, the APM BIOS does not automatically
773 power manage devices, enter the Standby State, enter the Suspend
774 State, or take power saving steps in response to CPU Idle calls."
775 This driver will make CPU Idle calls when Linux is idle (unless this
776 feature is turned off -- see "Do CPU IDLE calls", below). This
777 should always save battery power, but more complicated APM features
778 will be dependent on your BIOS implementation. You may need to turn
779 this option off if your computer hangs at boot time when using APM
780 support, or if it beeps continuously instead of suspending. Turn
781 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
782 T400CDT. This is off by default since most machines do fine without
786 bool "Make CPU Idle calls when idle"
789 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
790 On some machines, this can activate improved power savings, such as
791 a slowed CPU clock rate, when the machine is idle. These idle calls
792 are made after the idle loop has run for some length of time (e.g.,
793 333 mS). On some machines, this will cause a hang at boot time or
794 whenever the CPU becomes idle. (On machines with more than one CPU,
795 this option does nothing.)
797 config APM_DISPLAY_BLANK
798 bool "Enable console blanking using APM"
801 Enable console blanking using the APM. Some laptops can use this to
802 turn off the LCD backlight when the screen blanker of the Linux
803 virtual console blanks the screen. Note that this is only used by
804 the virtual console screen blanker, and won't turn off the backlight
805 when using the X Window system. This also doesn't have anything to
806 do with your VESA-compliant power-saving monitor. Further, this
807 option doesn't work for all laptops -- it might not turn off your
808 backlight at all, or it might print a lot of errors to the console,
809 especially if you are using gpm.
811 config APM_RTC_IS_GMT
812 bool "RTC stores time in GMT"
815 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
816 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
819 It is in fact recommended to store GMT in your RTC, because then you
820 don't have to worry about daylight savings time changes. The only
821 reason not to use GMT in your RTC is if you also run a broken OS
822 that doesn't understand GMT.
824 config APM_ALLOW_INTS
825 bool "Allow interrupts during APM BIOS calls"
828 Normally we disable external interrupts while we are making calls to
829 the APM BIOS as a measure to lessen the effects of a badly behaving
830 BIOS implementation. The BIOS should reenable interrupts if it
831 needs to. Unfortunately, some BIOSes do not -- especially those in
832 many of the newer IBM Thinkpads. If you experience hangs when you
833 suspend, try setting this to Y. Otherwise, say N.
835 config APM_REAL_MODE_POWER_OFF
836 bool "Use real mode APM BIOS call to power off"
839 Use real mode APM BIOS calls to switch off the computer. This is
840 a work-around for a number of buggy BIOSes. Switch this option on if
841 your computer crashes instead of powering off properly.
845 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
849 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
852 bool "PCI support" if !X86_VISWS
853 depends on !X86_VOYAGER
854 default y if X86_VISWS
856 Find out whether you have a PCI motherboard. PCI is the name of a
857 bus system, i.e. the way the CPU talks to the other stuff inside
858 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
859 VESA. If you have PCI, say Y, otherwise N.
861 The PCI-HOWTO, available from
862 <http://www.tldp.org/docs.html#howto>, contains valuable
863 information about which PCI hardware does work under Linux and which
867 prompt "PCI access mode"
868 depends on PCI && !X86_VISWS
871 On PCI systems, the BIOS can be used to detect the PCI devices and
872 determine their configuration. However, some old PCI motherboards
873 have BIOS bugs and may crash if this is done. Also, some embedded
874 PCI-based systems don't have any BIOS at all. Linux can also try to
875 detect the PCI hardware directly without using the BIOS.
877 With this option, you can specify how Linux should detect the
878 PCI devices. If you choose "BIOS", the BIOS will be used,
879 if you choose "Direct", the BIOS won't be used, and if you
880 choose "MMConfig", then PCI Express MMCONFIG will be used.
881 If you choose "Any", the kernel will try MMCONFIG, then the
882 direct access method and falls back to the BIOS if that doesn't
883 work. If unsure, go with the default, which is "Any".
888 config PCI_GOMMCONFIG
901 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
906 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
911 depends on PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
914 source "drivers/pci/pcie/Kconfig"
916 source "drivers/pci/Kconfig"
924 depends on !(X86_VOYAGER || X86_VISWS)
926 Find out whether you have ISA slots on your motherboard. ISA is the
927 name of a bus system, i.e. the way the CPU talks to the other stuff
928 inside your box. Other bus systems are PCI, EISA, MicroChannel
929 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
930 newer boards don't support it. If you have ISA, say Y, otherwise N.
936 The Extended Industry Standard Architecture (EISA) bus was
937 developed as an open alternative to the IBM MicroChannel bus.
939 The EISA bus provided some of the features of the IBM MicroChannel
940 bus while maintaining backward compatibility with cards made for
941 the older ISA bus. The EISA bus saw limited use between 1988 and
942 1995 when it was made obsolete by the PCI bus.
944 Say Y here if you are building a kernel for an EISA-based machine.
948 source "drivers/eisa/Kconfig"
951 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
952 default y if X86_VOYAGER
954 MicroChannel Architecture is found in some IBM PS/2 machines and
955 laptops. It is a bus system similar to PCI or ISA. See
956 <file:Documentation/mca.txt> (and especially the web page given
957 there) before attempting to build an MCA bus kernel.
959 source "drivers/mca/Kconfig"
962 tristate "NatSemi SCx200 support"
963 depends on !X86_VOYAGER
965 This provides basic support for the National Semiconductor SCx200
966 processor. Right now this is just a driver for the GPIO pins.
968 If you don't know what to do here, say N.
970 This support is also available as a module. If compiled as a
971 module, it will be called scx200.
974 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
975 depends on SMP && HOTPLUG && EXPERIMENTAL
977 Say Y here to experiment with turning CPUs off and on. CPUs
978 can be controlled through /sys/devices/system/cpu.
982 source "drivers/pcmcia/Kconfig"
984 source "drivers/pci/hotplug/Kconfig"
988 menu "Executable file formats"
990 source "fs/Kconfig.binfmt"
996 source "drivers/Kconfig"
1000 menu "Instrumentation Support"
1001 depends on EXPERIMENTAL
1003 source "arch/i386/oprofile/Kconfig"
1006 bool "Kprobes (EXPERIMENTAL)"
1008 Kprobes allows you to trap at almost any kernel address and
1009 execute a callback function. register_kprobe() establishes
1010 a probepoint and specifies the callback. Kprobes is useful
1011 for kernel debugging, non-intrusive instrumentation and testing.
1012 If in doubt, say "N".
1015 source "arch/i386/Kconfig.debug"
1017 source "security/Kconfig"
1019 source "crypto/Kconfig"
1021 source "lib/Kconfig"
1024 # Use the generic interrupt handling code in kernel/irq/:
1026 config GENERIC_HARDIRQS
1030 config GENERIC_IRQ_PROBE
1034 config GENERIC_PENDING_IRQ
1036 depends on GENERIC_HARDIRQS && SMP
1041 depends on SMP && !X86_VOYAGER
1046 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1049 config X86_BIOS_REBOOT
1051 depends on !(X86_VISWS || X86_VOYAGER)
1054 config X86_TRAMPOLINE
1056 depends on X86_SMP || (X86_VOYAGER && SMP)
projects / linux-2.6 / blob