| blob | 4a88cf7695b418927c61ce760259db85bbd68cfe |
1 # x86 configuration
2 mainmenu "Linux Kernel Configuration for x86"
4 # Select 32 or 64 bit
5 config 64BIT
6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
8 help
9 Say yes to build a 64-bit kernel - formerly known as x86_64
10 Say no to build a 32-bit kernel - formerly known as i386
12 config X86_32
13 def_bool !64BIT
15 config X86_64
16 def_bool 64BIT
18 ### Arch settings
19 config X86
20 def_bool y
21 select HAVE_IDE
22 select HAVE_OPROFILE
23 select HAVE_KPROBES
24 select HAVE_KVM
27 config GENERIC_LOCKBREAK
28 def_bool n
30 config GENERIC_TIME
31 def_bool y
33 config GENERIC_CMOS_UPDATE
34 def_bool y
36 config CLOCKSOURCE_WATCHDOG
37 def_bool y
39 config GENERIC_CLOCKEVENTS
40 def_bool y
42 config GENERIC_CLOCKEVENTS_BROADCAST
43 def_bool y
44 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
46 config LOCKDEP_SUPPORT
47 def_bool y
49 config STACKTRACE_SUPPORT
50 def_bool y
52 config HAVE_LATENCYTOP_SUPPORT
53 def_bool y
55 config SEMAPHORE_SLEEPERS
56 def_bool y
58 config FAST_CMPXCHG_LOCAL
59 bool
60 default y
62 config MMU
63 def_bool y
65 config ZONE_DMA
66 def_bool y
68 config QUICKLIST
69 def_bool X86_32
71 config SBUS
72 bool
74 config GENERIC_ISA_DMA
75 def_bool y
77 config GENERIC_IOMAP
78 def_bool y
80 config GENERIC_BUG
81 def_bool y
82 depends on BUG
84 config GENERIC_HWEIGHT
85 def_bool y
87 config GENERIC_GPIO
88 def_bool n
90 config ARCH_MAY_HAVE_PC_FDC
91 def_bool y
93 config DMI
94 def_bool y
96 config RWSEM_GENERIC_SPINLOCK
97 def_bool !X86_XADD
99 config RWSEM_XCHGADD_ALGORITHM
100 def_bool X86_XADD
102 config ARCH_HAS_ILOG2_U32
103 def_bool n
105 config ARCH_HAS_ILOG2_U64
106 def_bool n
108 config ARCH_HAS_CPU_IDLE_WAIT
109 def_bool y
111 config GENERIC_CALIBRATE_DELAY
112 def_bool y
114 config GENERIC_TIME_VSYSCALL
115 bool
116 default X86_64
118 config ARCH_HAS_CPU_RELAX
119 def_bool y
121 config HAVE_SETUP_PER_CPU_AREA
122 def_bool X86_64
124 config ARCH_HIBERNATION_POSSIBLE
125 def_bool y
126 depends on !SMP || !X86_VOYAGER
128 config ARCH_SUSPEND_POSSIBLE
129 def_bool y
130 depends on !X86_VOYAGER
132 config ZONE_DMA32
133 bool
134 default X86_64
136 config ARCH_POPULATES_NODE_MAP
137 def_bool y
139 config AUDIT_ARCH
140 bool
141 default X86_64
143 config ARCH_SUPPORTS_AOUT
144 def_bool y
146 # Use the generic interrupt handling code in kernel/irq/:
147 config GENERIC_HARDIRQS
148 bool
149 default y
151 config GENERIC_IRQ_PROBE
152 bool
153 default y
155 config GENERIC_PENDING_IRQ
156 bool
157 depends on GENERIC_HARDIRQS && SMP
158 default y
160 config X86_SMP
161 bool
162 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
163 default y
165 config X86_32_SMP
166 def_bool y
167 depends on X86_32 && SMP
169 config X86_64_SMP
170 def_bool y
171 depends on X86_64 && SMP
173 config X86_HT
174 bool
175 depends on SMP
176 depends on (X86_32 && !(X86_VISWS || X86_VOYAGER)) || (X86_64 && !MK8)
177 default y
179 config X86_BIOS_REBOOT
180 bool
181 depends on X86_32 && !(X86_VISWS || X86_VOYAGER)
182 default y
184 config X86_TRAMPOLINE
185 bool
186 depends on X86_SMP || (X86_VOYAGER && SMP)
187 default y
189 config KTIME_SCALAR
190 def_bool X86_32
191 source "init/Kconfig"
193 menu "Processor type and features"
195 source "kernel/time/Kconfig"
197 config SMP
198 bool "Symmetric multi-processing support"
199 ---help---
200 This enables support for systems with more than one CPU. If you have
201 a system with only one CPU, like most personal computers, say N. If
202 you have a system with more than one CPU, say Y.
204 If you say N here, the kernel will run on single and multiprocessor
205 machines, but will use only one CPU of a multiprocessor machine. If
206 you say Y here, the kernel will run on many, but not all,
207 singleprocessor machines. On a singleprocessor machine, the kernel
208 will run faster if you say N here.
210 Note that if you say Y here and choose architecture "586" or
211 "Pentium" under "Processor family", the kernel will not work on 486
212 architectures. Similarly, multiprocessor kernels for the "PPro"
213 architecture may not work on all Pentium based boards.
215 People using multiprocessor machines who say Y here should also say
216 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
217 Management" code will be disabled if you say Y here.
219 See also <file:Documentation/i386/IO-APIC.txt>,
220 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
221 <http://www.tldp.org/docs.html#howto>.
223 If you don't know what to do here, say N.
225 choice
226 prompt "Subarchitecture Type"
227 default X86_PC
229 config X86_PC
230 bool "PC-compatible"
231 help
232 Choose this option if your computer is a standard PC or compatible.
234 config X86_ELAN
235 bool "AMD Elan"
236 depends on X86_32
237 help
238 Select this for an AMD Elan processor.
240 Do not use this option for K6/Athlon/Opteron processors!
242 If unsure, choose "PC-compatible" instead.
244 config X86_VOYAGER
245 bool "Voyager (NCR)"
246 depends on X86_32
247 select SMP if !BROKEN
248 help
249 Voyager is an MCA-based 32-way capable SMP architecture proprietary
250 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
252 *** WARNING ***
254 If you do not specifically know you have a Voyager based machine,
255 say N here, otherwise the kernel you build will not be bootable.
257 config X86_NUMAQ
258 bool "NUMAQ (IBM/Sequent)"
259 select SMP
260 select NUMA
261 depends on X86_32
262 help
263 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
264 multiquad box. This changes the way that processors are bootstrapped,
265 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
266 You will need a new lynxer.elf file to flash your firmware with - send
267 email to <Martin.Bligh@us.ibm.com>.
269 config X86_SUMMIT
270 bool "Summit/EXA (IBM x440)"
271 depends on X86_32 && SMP
272 help
273 This option is needed for IBM systems that use the Summit/EXA chipset.
274 In particular, it is needed for the x440.
276 If you don't have one of these computers, you should say N here.
277 If you want to build a NUMA kernel, you must select ACPI.
279 config X86_BIGSMP
280 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
281 depends on X86_32 && SMP
282 help
283 This option is needed for the systems that have more than 8 CPUs
284 and if the system is not of any sub-arch type above.
286 If you don't have such a system, you should say N here.
288 config X86_VISWS
289 bool "SGI 320/540 (Visual Workstation)"
290 depends on X86_32
291 help
292 The SGI Visual Workstation series is an IA32-based workstation
293 based on SGI systems chips with some legacy PC hardware attached.
295 Say Y here to create a kernel to run on the SGI 320 or 540.
297 A kernel compiled for the Visual Workstation will not run on PCs
298 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
300 config X86_GENERICARCH
301 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
302 depends on X86_32
303 help
304 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
305 It is intended for a generic binary kernel.
306 If you want a NUMA kernel, select ACPI. We need SRAT for NUMA.
308 config X86_ES7000
309 bool "Support for Unisys ES7000 IA32 series"
310 depends on X86_32 && SMP
311 help
312 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
313 supposed to run on an IA32-based Unisys ES7000 system.
314 Only choose this option if you have such a system, otherwise you
315 should say N here.
317 config X86_RDC321X
318 bool "RDC R-321x SoC"
319 depends on X86_32
320 select M486
321 select X86_REBOOTFIXUPS
322 select GENERIC_GPIO
323 select LEDS_CLASS
324 select LEDS_GPIO
325 help
326 This option is needed for RDC R-321x system-on-chip, also known
327 as R-8610-(G).
328 If you don't have one of these chips, you should say N here.
330 config X86_VSMP
331 bool "Support for ScaleMP vSMP"
332 depends on X86_64 && PCI
333 help
334 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
335 supposed to run on these EM64T-based machines. Only choose this option
336 if you have one of these machines.
338 endchoice
340 config SCHED_NO_NO_OMIT_FRAME_POINTER
341 def_bool y
342 prompt "Single-depth WCHAN output"
343 depends on X86_32
344 help
345 Calculate simpler /proc/<PID>/wchan values. If this option
346 is disabled then wchan values will recurse back to the
347 caller function. This provides more accurate wchan values,
348 at the expense of slightly more scheduling overhead.
350 If in doubt, say "Y".
352 menuconfig PARAVIRT_GUEST
353 bool "Paravirtualized guest support"
354 help
355 Say Y here to get to see options related to running Linux under
356 various hypervisors. This option alone does not add any kernel code.
358 If you say N, all options in this submenu will be skipped and disabled.
360 if PARAVIRT_GUEST
362 source "arch/x86/xen/Kconfig"
364 config VMI
365 bool "VMI Guest support"
366 select PARAVIRT
367 depends on X86_32
368 depends on !(X86_VISWS || X86_VOYAGER)
369 help
370 VMI provides a paravirtualized interface to the VMware ESX server
371 (it could be used by other hypervisors in theory too, but is not
372 at the moment), by linking the kernel to a GPL-ed ROM module
373 provided by the hypervisor.
375 source "arch/x86/lguest/Kconfig"
377 config PARAVIRT
378 bool "Enable paravirtualization code"
379 depends on !(X86_VISWS || X86_VOYAGER)
380 help
381 This changes the kernel so it can modify itself when it is run
382 under a hypervisor, potentially improving performance significantly
383 over full virtualization. However, when run without a hypervisor
384 the kernel is theoretically slower and slightly larger.
386 endif
388 config ACPI_SRAT
389 def_bool y
390 depends on X86_32 && ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
391 select ACPI_NUMA
393 config HAVE_ARCH_PARSE_SRAT
394 def_bool y
395 depends on ACPI_SRAT
397 config X86_SUMMIT_NUMA
398 def_bool y
399 depends on X86_32 && NUMA && (X86_SUMMIT || X86_GENERICARCH)
401 config X86_CYCLONE_TIMER
402 def_bool y
403 depends on X86_32 && X86_SUMMIT || X86_GENERICARCH
405 config ES7000_CLUSTERED_APIC
406 def_bool y
407 depends on SMP && X86_ES7000 && MPENTIUMIII
409 source "arch/x86/Kconfig.cpu"
411 config HPET_TIMER
412 def_bool X86_64
413 prompt "HPET Timer Support" if X86_32
414 help
415 Use the IA-PC HPET (High Precision Event Timer) to manage
416 time in preference to the PIT and RTC, if a HPET is
417 present.
418 HPET is the next generation timer replacing legacy 8254s.
419 The HPET provides a stable time base on SMP
420 systems, unlike the TSC, but it is more expensive to access,
421 as it is off-chip. You can find the HPET spec at
422 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
424 You can safely choose Y here. However, HPET will only be
425 activated if the platform and the BIOS support this feature.
426 Otherwise the 8254 will be used for timing services.
428 Choose N to continue using the legacy 8254 timer.
430 config HPET_EMULATE_RTC
431 def_bool y
432 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
434 # Mark as embedded because too many people got it wrong.
435 # The code disables itself when not needed.
436 config GART_IOMMU
437 bool "GART IOMMU support" if EMBEDDED
438 default y
439 select SWIOTLB
440 select AGP
441 depends on X86_64 && PCI
442 help
443 Support for full DMA access of devices with 32bit memory access only
444 on systems with more than 3GB. This is usually needed for USB,
445 sound, many IDE/SATA chipsets and some other devices.
446 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
447 based hardware IOMMU and a software bounce buffer based IOMMU used
448 on Intel systems and as fallback.
449 The code is only active when needed (enough memory and limited
450 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
451 too.
453 config CALGARY_IOMMU
454 bool "IBM Calgary IOMMU support"
455 select SWIOTLB
456 depends on X86_64 && PCI && EXPERIMENTAL
457 help
458 Support for hardware IOMMUs in IBM's xSeries x366 and x460
459 systems. Needed to run systems with more than 3GB of memory
460 properly with 32-bit PCI devices that do not support DAC
461 (Double Address Cycle). Calgary also supports bus level
462 isolation, where all DMAs pass through the IOMMU. This
463 prevents them from going anywhere except their intended
464 destination. This catches hard-to-find kernel bugs and
465 mis-behaving drivers and devices that do not use the DMA-API
466 properly to set up their DMA buffers. The IOMMU can be
467 turned off at boot time with the iommu=off parameter.
468 Normally the kernel will make the right choice by itself.
469 If unsure, say Y.
471 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
472 def_bool y
473 prompt "Should Calgary be enabled by default?"
474 depends on CALGARY_IOMMU
475 help
476 Should Calgary be enabled by default? if you choose 'y', Calgary
477 will be used (if it exists). If you choose 'n', Calgary will not be
478 used even if it exists. If you choose 'n' and would like to use
479 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
480 If unsure, say Y.
482 config IOMMU_HELPER
483 def_bool (CALGARY_IOMMU || GART_IOMMU)
485 # need this always selected by IOMMU for the VIA workaround
486 config SWIOTLB
487 bool
488 help
489 Support for software bounce buffers used on x86-64 systems
490 which don't have a hardware IOMMU (e.g. the current generation
491 of Intel's x86-64 CPUs). Using this PCI devices which can only
492 access 32-bits of memory can be used on systems with more than
493 3 GB of memory. If unsure, say Y.
496 config NR_CPUS
497 int "Maximum number of CPUs (2-255)"
498 range 2 255
499 depends on SMP
500 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
501 default "8"
502 help
503 This allows you to specify the maximum number of CPUs which this
504 kernel will support. The maximum supported value is 255 and the
505 minimum value which makes sense is 2.
507 This is purely to save memory - each supported CPU adds
508 approximately eight kilobytes to the kernel image.
510 config SCHED_SMT
511 bool "SMT (Hyperthreading) scheduler support"
512 depends on (X86_64 && SMP) || (X86_32 && X86_HT)
513 help
514 SMT scheduler support improves the CPU scheduler's decision making
515 when dealing with Intel Pentium 4 chips with HyperThreading at a
516 cost of slightly increased overhead in some places. If unsure say
517 N here.
519 config SCHED_MC
520 def_bool y
521 prompt "Multi-core scheduler support"
522 depends on (X86_64 && SMP) || (X86_32 && X86_HT)
523 help
524 Multi-core scheduler support improves the CPU scheduler's decision
525 making when dealing with multi-core CPU chips at a cost of slightly
526 increased overhead in some places. If unsure say N here.
528 source "kernel/Kconfig.preempt"
530 config X86_UP_APIC
531 bool "Local APIC support on uniprocessors"
532 depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
533 help
534 A local APIC (Advanced Programmable Interrupt Controller) is an
535 integrated interrupt controller in the CPU. If you have a single-CPU
536 system which has a processor with a local APIC, you can say Y here to
537 enable and use it. If you say Y here even though your machine doesn't
538 have a local APIC, then the kernel will still run with no slowdown at
539 all. The local APIC supports CPU-generated self-interrupts (timer,
540 performance counters), and the NMI watchdog which detects hard
541 lockups.
543 config X86_UP_IOAPIC
544 bool "IO-APIC support on uniprocessors"
545 depends on X86_UP_APIC
546 help
547 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
548 SMP-capable replacement for PC-style interrupt controllers. Most
549 SMP systems and many recent uniprocessor systems have one.
551 If you have a single-CPU system with an IO-APIC, you can say Y here
552 to use it. If you say Y here even though your machine doesn't have
553 an IO-APIC, then the kernel will still run with no slowdown at all.
555 config X86_LOCAL_APIC
556 def_bool y
557 depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH))
559 config X86_IO_APIC
560 def_bool y
561 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH))
563 config X86_VISWS_APIC
564 def_bool y
565 depends on X86_32 && X86_VISWS
567 config X86_MCE
568 bool "Machine Check Exception"
569 depends on !X86_VOYAGER
570 ---help---
571 Machine Check Exception support allows the processor to notify the
572 kernel if it detects a problem (e.g. overheating, component failure).
573 The action the kernel takes depends on the severity of the problem,
574 ranging from a warning message on the console, to halting the machine.
575 Your processor must be a Pentium or newer to support this - check the
576 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
577 have a design flaw which leads to false MCE events - hence MCE is
578 disabled on all P5 processors, unless explicitly enabled with "mce"
579 as a boot argument. Similarly, if MCE is built in and creates a
580 problem on some new non-standard machine, you can boot with "nomce"
581 to disable it. MCE support simply ignores non-MCE processors like
582 the 386 and 486, so nearly everyone can say Y here.
584 config X86_MCE_INTEL
585 def_bool y
586 prompt "Intel MCE features"
587 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
588 help
589 Additional support for intel specific MCE features such as
590 the thermal monitor.
592 config X86_MCE_AMD
593 def_bool y
594 prompt "AMD MCE features"
595 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
596 help
597 Additional support for AMD specific MCE features such as
598 the DRAM Error Threshold.
600 config X86_MCE_NONFATAL
601 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
602 depends on X86_32 && X86_MCE
603 help
604 Enabling this feature starts a timer that triggers every 5 seconds which
605 will look at the machine check registers to see if anything happened.
606 Non-fatal problems automatically get corrected (but still logged).
607 Disable this if you don't want to see these messages.
608 Seeing the messages this option prints out may be indicative of dying
609 or out-of-spec (ie, overclocked) hardware.
610 This option only does something on certain CPUs.
611 (AMD Athlon/Duron and Intel Pentium 4)
613 config X86_MCE_P4THERMAL
614 bool "check for P4 thermal throttling interrupt."
615 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
616 help
617 Enabling this feature will cause a message to be printed when the P4
618 enters thermal throttling.
620 config VM86
621 bool "Enable VM86 support" if EMBEDDED
622 default y
623 depends on X86_32
624 help
625 This option is required by programs like DOSEMU to run 16-bit legacy
626 code on X86 processors. It also may be needed by software like
627 XFree86 to initialize some video cards via BIOS. Disabling this
628 option saves about 6k.
630 config TOSHIBA
631 tristate "Toshiba Laptop support"
632 depends on X86_32
633 ---help---
634 This adds a driver to safely access the System Management Mode of
635 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
636 not work on models with a Phoenix BIOS. The System Management Mode
637 is used to set the BIOS and power saving options on Toshiba portables.
639 For information on utilities to make use of this driver see the
640 Toshiba Linux utilities web site at:
641 <http://www.buzzard.org.uk/toshiba/>.
643 Say Y if you intend to run this kernel on a Toshiba portable.
644 Say N otherwise.
646 config I8K
647 tristate "Dell laptop support"
648 ---help---
649 This adds a driver to safely access the System Management Mode
650 of the CPU on the Dell Inspiron 8000. The System Management Mode
651 is used to read cpu temperature and cooling fan status and to
652 control the fans on the I8K portables.
654 This driver has been tested only on the Inspiron 8000 but it may
655 also work with other Dell laptops. You can force loading on other
656 models by passing the parameter `force=1' to the module. Use at
657 your own risk.
659 For information on utilities to make use of this driver see the
660 I8K Linux utilities web site at:
661 <http://people.debian.org/~dz/i8k/>
663 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
664 Say N otherwise.
666 config X86_REBOOTFIXUPS
667 def_bool n
668 prompt "Enable X86 board specific fixups for reboot"
669 depends on X86_32 && X86
670 ---help---
671 This enables chipset and/or board specific fixups to be done
672 in order to get reboot to work correctly. This is only needed on
673 some combinations of hardware and BIOS. The symptom, for which
674 this config is intended, is when reboot ends with a stalled/hung
675 system.
677 Currently, the only fixup is for the Geode machines using
678 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
680 Say Y if you want to enable the fixup. Currently, it's safe to
681 enable this option even if you don't need it.
682 Say N otherwise.
684 config MICROCODE
685 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
686 select FW_LOADER
687 ---help---
688 If you say Y here, you will be able to update the microcode on
689 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
690 Pentium III, Pentium 4, Xeon etc. You will obviously need the
691 actual microcode binary data itself which is not shipped with the
692 Linux kernel.
694 For latest news and information on obtaining all the required
695 ingredients for this driver, check:
696 <http://www.urbanmyth.org/microcode/>.
698 To compile this driver as a module, choose M here: the
699 module will be called microcode.
701 config MICROCODE_OLD_INTERFACE
702 def_bool y
703 depends on MICROCODE
705 config X86_MSR
706 tristate "/dev/cpu/*/msr - Model-specific register support"
707 help
708 This device gives privileged processes access to the x86
709 Model-Specific Registers (MSRs). It is a character device with
710 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
711 MSR accesses are directed to a specific CPU on multi-processor
712 systems.
714 config X86_CPUID
715 tristate "/dev/cpu/*/cpuid - CPU information support"
716 help
717 This device gives processes access to the x86 CPUID instruction to
718 be executed on a specific processor. It is a character device
719 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
720 /dev/cpu/31/cpuid.
722 choice
723 prompt "High Memory Support"
724 default HIGHMEM4G if !X86_NUMAQ
725 default HIGHMEM64G if X86_NUMAQ
726 depends on X86_32
728 config NOHIGHMEM
729 bool "off"
730 depends on !X86_NUMAQ
731 ---help---
732 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
733 However, the address space of 32-bit x86 processors is only 4
734 Gigabytes large. That means that, if you have a large amount of
735 physical memory, not all of it can be "permanently mapped" by the
736 kernel. The physical memory that's not permanently mapped is called
737 "high memory".
739 If you are compiling a kernel which will never run on a machine with
740 more than 1 Gigabyte total physical RAM, answer "off" here (default
741 choice and suitable for most users). This will result in a "3GB/1GB"
742 split: 3GB are mapped so that each process sees a 3GB virtual memory
743 space and the remaining part of the 4GB virtual memory space is used
744 by the kernel to permanently map as much physical memory as
745 possible.
747 If the machine has between 1 and 4 Gigabytes physical RAM, then
748 answer "4GB" here.
750 If more than 4 Gigabytes is used then answer "64GB" here. This
751 selection turns Intel PAE (Physical Address Extension) mode on.
752 PAE implements 3-level paging on IA32 processors. PAE is fully
753 supported by Linux, PAE mode is implemented on all recent Intel
754 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
755 then the kernel will not boot on CPUs that don't support PAE!
757 The actual amount of total physical memory will either be
758 auto detected or can be forced by using a kernel command line option
759 such as "mem=256M". (Try "man bootparam" or see the documentation of
760 your boot loader (lilo or loadlin) about how to pass options to the
761 kernel at boot time.)
763 If unsure, say "off".
765 config HIGHMEM4G
766 bool "4GB"
767 depends on !X86_NUMAQ
768 help
769 Select this if you have a 32-bit processor and between 1 and 4
770 gigabytes of physical RAM.
772 config HIGHMEM64G
773 bool "64GB"
774 depends on !M386 && !M486
775 select X86_PAE
776 help
777 Select this if you have a 32-bit processor and more than 4
778 gigabytes of physical RAM.
780 endchoice
782 choice
783 depends on EXPERIMENTAL
784 prompt "Memory split" if EMBEDDED
785 default VMSPLIT_3G
786 depends on X86_32
787 help
788 Select the desired split between kernel and user memory.
790 If the address range available to the kernel is less than the
791 physical memory installed, the remaining memory will be available
792 as "high memory". Accessing high memory is a little more costly
793 than low memory, as it needs to be mapped into the kernel first.
794 Note that increasing the kernel address space limits the range
795 available to user programs, making the address space there
796 tighter. Selecting anything other than the default 3G/1G split
797 will also likely make your kernel incompatible with binary-only
798 kernel modules.
800 If you are not absolutely sure what you are doing, leave this
801 option alone!
803 config VMSPLIT_3G
804 bool "3G/1G user/kernel split"
805 config VMSPLIT_3G_OPT
806 depends on !X86_PAE
807 bool "3G/1G user/kernel split (for full 1G low memory)"
808 config VMSPLIT_2G
809 bool "2G/2G user/kernel split"
810 config VMSPLIT_2G_OPT
811 depends on !X86_PAE
812 bool "2G/2G user/kernel split (for full 2G low memory)"
813 config VMSPLIT_1G
814 bool "1G/3G user/kernel split"
815 endchoice
817 config PAGE_OFFSET
818 hex
819 default 0xB0000000 if VMSPLIT_3G_OPT
820 default 0x80000000 if VMSPLIT_2G
821 default 0x78000000 if VMSPLIT_2G_OPT
822 default 0x40000000 if VMSPLIT_1G
823 default 0xC0000000
824 depends on X86_32
826 config HIGHMEM
827 def_bool y
828 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
830 config X86_PAE
831 def_bool n
832 prompt "PAE (Physical Address Extension) Support"
833 depends on X86_32 && !HIGHMEM4G
834 select RESOURCES_64BIT
835 help
836 PAE is required for NX support, and furthermore enables
837 larger swapspace support for non-overcommit purposes. It
838 has the cost of more pagetable lookup overhead, and also
839 consumes more pagetable space per process.
841 # Common NUMA Features
842 config NUMA
843 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
844 depends on SMP
845 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) && EXPERIMENTAL)
846 default n if X86_PC
847 default y if (X86_NUMAQ || X86_SUMMIT)
848 help
849 Enable NUMA (Non Uniform Memory Access) support.
850 The kernel will try to allocate memory used by a CPU on the
851 local memory controller of the CPU and add some more
852 NUMA awareness to the kernel.
854 For i386 this is currently highly experimental and should be only
855 used for kernel development. It might also cause boot failures.
856 For x86_64 this is recommended on all multiprocessor Opteron systems.
857 If the system is EM64T, you should say N unless your system is
858 EM64T NUMA.
860 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
861 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
863 config K8_NUMA
864 def_bool y
865 prompt "Old style AMD Opteron NUMA detection"
866 depends on X86_64 && NUMA && PCI
867 help
868 Enable K8 NUMA node topology detection. You should say Y here if
869 you have a multi processor AMD K8 system. This uses an old
870 method to read the NUMA configuration directly from the builtin
871 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
872 instead, which also takes priority if both are compiled in.
874 config X86_64_ACPI_NUMA
875 def_bool y
876 prompt "ACPI NUMA detection"
877 depends on X86_64 && NUMA && ACPI && PCI
878 select ACPI_NUMA
879 help
880 Enable ACPI SRAT based node topology detection.
882 config NUMA_EMU
883 bool "NUMA emulation"
884 depends on X86_64 && NUMA
885 help
886 Enable NUMA emulation. A flat machine will be split
887 into virtual nodes when booted with "numa=fake=N", where N is the
888 number of nodes. This is only useful for debugging.
890 config NODES_SHIFT
891 int
892 range 1 15 if X86_64
893 default "6" if X86_64
894 default "4" if X86_NUMAQ
895 default "3"
896 depends on NEED_MULTIPLE_NODES
898 config HAVE_ARCH_BOOTMEM_NODE
899 def_bool y
900 depends on X86_32 && NUMA
902 config ARCH_HAVE_MEMORY_PRESENT
903 def_bool y
904 depends on X86_32 && DISCONTIGMEM
906 config NEED_NODE_MEMMAP_SIZE
907 def_bool y
908 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
910 config HAVE_ARCH_ALLOC_REMAP
911 def_bool y
912 depends on X86_32 && NUMA
914 config ARCH_FLATMEM_ENABLE
915 def_bool y
916 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
918 config ARCH_DISCONTIGMEM_ENABLE
919 def_bool y
920 depends on NUMA && X86_32
922 config ARCH_DISCONTIGMEM_DEFAULT
923 def_bool y
924 depends on NUMA && X86_32
926 config ARCH_SPARSEMEM_DEFAULT
927 def_bool y
928 depends on X86_64
930 config ARCH_SPARSEMEM_ENABLE
931 def_bool y
932 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
933 select SPARSEMEM_STATIC if X86_32
934 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
936 config ARCH_SELECT_MEMORY_MODEL
937 def_bool y
938 depends on ARCH_SPARSEMEM_ENABLE
940 config ARCH_MEMORY_PROBE
941 def_bool X86_64
942 depends on MEMORY_HOTPLUG
944 source "mm/Kconfig"
946 config HIGHPTE
947 bool "Allocate 3rd-level pagetables from highmem"
948 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
949 help
950 The VM uses one page table entry for each page of physical memory.
951 For systems with a lot of RAM, this can be wasteful of precious
952 low memory. Setting this option will put user-space page table
953 entries in high memory.
955 config MATH_EMULATION
956 bool
957 prompt "Math emulation" if X86_32
958 ---help---
959 Linux can emulate a math coprocessor (used for floating point
960 operations) if you don't have one. 486DX and Pentium processors have
961 a math coprocessor built in, 486SX and 386 do not, unless you added
962 a 487DX or 387, respectively. (The messages during boot time can
963 give you some hints here ["man dmesg"].) Everyone needs either a
964 coprocessor or this emulation.
966 If you don't have a math coprocessor, you need to say Y here; if you
967 say Y here even though you have a coprocessor, the coprocessor will
968 be used nevertheless. (This behavior can be changed with the kernel
969 command line option "no387", which comes handy if your coprocessor
970 is broken. Try "man bootparam" or see the documentation of your boot
971 loader (lilo or loadlin) about how to pass options to the kernel at
972 boot time.) This means that it is a good idea to say Y here if you
973 intend to use this kernel on different machines.
975 More information about the internals of the Linux math coprocessor
976 emulation can be found in <file:arch/x86/math-emu/README>.
978 If you are not sure, say Y; apart from resulting in a 66 KB bigger
979 kernel, it won't hurt.
981 config MTRR
982 bool "MTRR (Memory Type Range Register) support"
983 ---help---
984 On Intel P6 family processors (Pentium Pro, Pentium II and later)
985 the Memory Type Range Registers (MTRRs) may be used to control
986 processor access to memory ranges. This is most useful if you have
987 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
988 allows bus write transfers to be combined into a larger transfer
989 before bursting over the PCI/AGP bus. This can increase performance
990 of image write operations 2.5 times or more. Saying Y here creates a
991 /proc/mtrr file which may be used to manipulate your processor's
992 MTRRs. Typically the X server should use this.
994 This code has a reasonably generic interface so that similar
995 control registers on other processors can be easily supported
996 as well:
998 The Cyrix 6x86, 6x86MX and M II processors have Address Range
999 Registers (ARRs) which provide a similar functionality to MTRRs. For
1000 these, the ARRs are used to emulate the MTRRs.
1001 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1002 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1003 write-combining. All of these processors are supported by this code
1004 and it makes sense to say Y here if you have one of them.
1006 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1007 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1008 can lead to all sorts of problems, so it's good to say Y here.
1010 You can safely say Y even if your machine doesn't have MTRRs, you'll
1011 just add about 9 KB to your kernel.
1013 See <file:Documentation/mtrr.txt> for more information.
1015 config EFI
1016 def_bool n
1017 prompt "EFI runtime service support"
1018 depends on ACPI
1019 ---help---
1020 This enables the kernel to use EFI runtime services that are
1021 available (such as the EFI variable services).
1023 This option is only useful on systems that have EFI firmware.
1024 In addition, you should use the latest ELILO loader available
1025 at <http://elilo.sourceforge.net> in order to take advantage
1026 of EFI runtime services. However, even with this option, the
1027 resultant kernel should continue to boot on existing non-EFI
1028 platforms.
1030 config IRQBALANCE
1031 def_bool y
1032 prompt "Enable kernel irq balancing"
1033 depends on X86_32 && SMP && X86_IO_APIC
1034 help
1035 The default yes will allow the kernel to do irq load balancing.
1036 Saying no will keep the kernel from doing irq load balancing.
1038 config SECCOMP
1039 def_bool y
1040 prompt "Enable seccomp to safely compute untrusted bytecode"
1041 depends on PROC_FS
1042 help
1043 This kernel feature is useful for number crunching applications
1044 that may need to compute untrusted bytecode during their
1045 execution. By using pipes or other transports made available to
1046 the process as file descriptors supporting the read/write
1047 syscalls, it's possible to isolate those applications in
1048 their own address space using seccomp. Once seccomp is
1049 enabled via /proc/<pid>/seccomp, it cannot be disabled
1050 and the task is only allowed to execute a few safe syscalls
1051 defined by each seccomp mode.
1053 If unsure, say Y. Only embedded should say N here.
1055 config CC_STACKPROTECTOR
1056 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1057 depends on X86_64 && EXPERIMENTAL && BROKEN
1058 help
1059 This option turns on the -fstack-protector GCC feature. This
1060 feature puts, at the beginning of critical functions, a canary
1061 value on the stack just before the return address, and validates
1062 the value just before actually returning. Stack based buffer
1063 overflows (that need to overwrite this return address) now also
1064 overwrite the canary, which gets detected and the attack is then
1065 neutralized via a kernel panic.
1067 This feature requires gcc version 4.2 or above, or a distribution
1068 gcc with the feature backported. Older versions are automatically
1069 detected and for those versions, this configuration option is ignored.
1071 config CC_STACKPROTECTOR_ALL
1072 bool "Use stack-protector for all functions"
1073 depends on CC_STACKPROTECTOR
1074 help
1075 Normally, GCC only inserts the canary value protection for
1076 functions that use large-ish on-stack buffers. By enabling
1077 this option, GCC will be asked to do this for ALL functions.
1079 source kernel/Kconfig.hz
1081 config KEXEC
1082 bool "kexec system call"
1083 help
1084 kexec is a system call that implements the ability to shutdown your
1085 current kernel, and to start another kernel. It is like a reboot
1086 but it is independent of the system firmware. And like a reboot
1087 you can start any kernel with it, not just Linux.
1089 The name comes from the similarity to the exec system call.
1091 It is an ongoing process to be certain the hardware in a machine
1092 is properly shutdown, so do not be surprised if this code does not
1093 initially work for you. It may help to enable device hotplugging
1094 support. As of this writing the exact hardware interface is
1095 strongly in flux, so no good recommendation can be made.
1097 config CRASH_DUMP
1098 bool "kernel crash dumps (EXPERIMENTAL)"
1099 depends on EXPERIMENTAL
1100 depends on X86_64 || (X86_32 && HIGHMEM)
1101 help
1102 Generate crash dump after being started by kexec.
1103 This should be normally only set in special crash dump kernels
1104 which are loaded in the main kernel with kexec-tools into
1105 a specially reserved region and then later executed after
1106 a crash by kdump/kexec. The crash dump kernel must be compiled
1107 to a memory address not used by the main kernel or BIOS using
1108 PHYSICAL_START, or it must be built as a relocatable image
1109 (CONFIG_RELOCATABLE=y).
1110 For more details see Documentation/kdump/kdump.txt
1112 config PHYSICAL_START
1113 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1114 default "0x1000000" if X86_NUMAQ
1115 default "0x200000" if X86_64
1116 default "0x100000"
1117 help
1118 This gives the physical address where the kernel is loaded.
1120 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1121 bzImage will decompress itself to above physical address and
1122 run from there. Otherwise, bzImage will run from the address where
1123 it has been loaded by the boot loader and will ignore above physical
1124 address.
1126 In normal kdump cases one does not have to set/change this option
1127 as now bzImage can be compiled as a completely relocatable image
1128 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1129 address. This option is mainly useful for the folks who don't want
1130 to use a bzImage for capturing the crash dump and want to use a
1131 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1132 to be specifically compiled to run from a specific memory area
1133 (normally a reserved region) and this option comes handy.
1135 So if you are using bzImage for capturing the crash dump, leave
1136 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1137 Otherwise if you plan to use vmlinux for capturing the crash dump
1138 change this value to start of the reserved region (Typically 16MB
1139 0x1000000). In other words, it can be set based on the "X" value as
1140 specified in the "crashkernel=YM@XM" command line boot parameter
1141 passed to the panic-ed kernel. Typically this parameter is set as
1142 crashkernel=64M@16M. Please take a look at
1143 Documentation/kdump/kdump.txt for more details about crash dumps.
1145 Usage of bzImage for capturing the crash dump is recommended as
1146 one does not have to build two kernels. Same kernel can be used
1147 as production kernel and capture kernel. Above option should have
1148 gone away after relocatable bzImage support is introduced. But it
1149 is present because there are users out there who continue to use
1150 vmlinux for dump capture. This option should go away down the
1151 line.
1153 Don't change this unless you know what you are doing.
1155 config RELOCATABLE
1156 bool "Build a relocatable kernel (EXPERIMENTAL)"
1157 depends on EXPERIMENTAL
1158 help
1159 This builds a kernel image that retains relocation information
1160 so it can be loaded someplace besides the default 1MB.
1161 The relocations tend to make the kernel binary about 10% larger,
1162 but are discarded at runtime.
1164 One use is for the kexec on panic case where the recovery kernel
1165 must live at a different physical address than the primary
1166 kernel.
1168 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1169 it has been loaded at and the compile time physical address
1170 (CONFIG_PHYSICAL_START) is ignored.
1172 config PHYSICAL_ALIGN
1173 hex
1174 prompt "Alignment value to which kernel should be aligned" if X86_32
1175 default "0x100000" if X86_32
1176 default "0x200000" if X86_64
1177 range 0x2000 0x400000
1178 help
1179 This value puts the alignment restrictions on physical address
1180 where kernel is loaded and run from. Kernel is compiled for an
1181 address which meets above alignment restriction.
1183 If bootloader loads the kernel at a non-aligned address and
1184 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1185 address aligned to above value and run from there.
1187 If bootloader loads the kernel at a non-aligned address and
1188 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1189 load address and decompress itself to the address it has been
1190 compiled for and run from there. The address for which kernel is
1191 compiled already meets above alignment restrictions. Hence the
1192 end result is that kernel runs from a physical address meeting
1193 above alignment restrictions.
1195 Don't change this unless you know what you are doing.
1197 config HOTPLUG_CPU
1198 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1199 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1200 ---help---
1201 Say Y here to experiment with turning CPUs off and on, and to
1202 enable suspend on SMP systems. CPUs can be controlled through
1203 /sys/devices/system/cpu.
1204 Say N if you want to disable CPU hotplug and don't need to
1205 suspend.
1207 config COMPAT_VDSO
1208 def_bool y
1209 prompt "Compat VDSO support"
1210 depends on X86_32 || IA32_EMULATION
1211 help
1212 Map the 32-bit VDSO to the predictable old-style address too.
1213 ---help---
1214 Say N here if you are running a sufficiently recent glibc
1215 version (2.3.3 or later), to remove the high-mapped
1216 VDSO mapping and to exclusively use the randomized VDSO.
1218 If unsure, say Y.
1220 endmenu
1222 config ARCH_ENABLE_MEMORY_HOTPLUG
1223 def_bool y
1224 depends on X86_64 || (X86_32 && HIGHMEM)
1226 config HAVE_ARCH_EARLY_PFN_TO_NID
1227 def_bool X86_64
1228 depends on NUMA
1230 menu "Power management options"
1231 depends on !X86_VOYAGER
1233 config ARCH_HIBERNATION_HEADER
1234 def_bool y
1235 depends on X86_64 && HIBERNATION
1237 source "kernel/power/Kconfig"
1239 source "drivers/acpi/Kconfig"
1241 config X86_APM_BOOT
1242 bool
1243 default y
1244 depends on APM || APM_MODULE
1246 menuconfig APM
1247 tristate "APM (Advanced Power Management) BIOS support"
1248 depends on X86_32 && PM_SLEEP && !X86_VISWS
1249 ---help---
1250 APM is a BIOS specification for saving power using several different
1251 techniques. This is mostly useful for battery powered laptops with
1252 APM compliant BIOSes. If you say Y here, the system time will be
1253 reset after a RESUME operation, the /proc/apm device will provide
1254 battery status information, and user-space programs will receive
1255 notification of APM "events" (e.g. battery status change).
1257 If you select "Y" here, you can disable actual use of the APM
1258 BIOS by passing the "apm=off" option to the kernel at boot time.
1260 Note that the APM support is almost completely disabled for
1261 machines with more than one CPU.
1263 In order to use APM, you will need supporting software. For location
1264 and more information, read <file:Documentation/pm.txt> and the
1265 Battery Powered Linux mini-HOWTO, available from
1266 <http://www.tldp.org/docs.html#howto>.
1268 This driver does not spin down disk drives (see the hdparm(8)
1269 manpage ("man 8 hdparm") for that), and it doesn't turn off
1270 VESA-compliant "green" monitors.
1272 This driver does not support the TI 4000M TravelMate and the ACER
1273 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1274 desktop machines also don't have compliant BIOSes, and this driver
1275 may cause those machines to panic during the boot phase.
1277 Generally, if you don't have a battery in your machine, there isn't
1278 much point in using this driver and you should say N. If you get
1279 random kernel OOPSes or reboots that don't seem to be related to
1280 anything, try disabling/enabling this option (or disabling/enabling
1281 APM in your BIOS).
1283 Some other things you should try when experiencing seemingly random,
1284 "weird" problems:
1286 1) make sure that you have enough swap space and that it is
1287 enabled.
1288 2) pass the "no-hlt" option to the kernel
1289 3) switch on floating point emulation in the kernel and pass
1290 the "no387" option to the kernel
1291 4) pass the "floppy=nodma" option to the kernel
1292 5) pass the "mem=4M" option to the kernel (thereby disabling
1293 all but the first 4 MB of RAM)
1294 6) make sure that the CPU is not over clocked.
1295 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1296 8) disable the cache from your BIOS settings
1297 9) install a fan for the video card or exchange video RAM
1298 10) install a better fan for the CPU
1299 11) exchange RAM chips
1300 12) exchange the motherboard.
1302 To compile this driver as a module, choose M here: the
1303 module will be called apm.
1305 if APM
1307 config APM_IGNORE_USER_SUSPEND
1308 bool "Ignore USER SUSPEND"
1309 help
1310 This option will ignore USER SUSPEND requests. On machines with a
1311 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1312 series notebooks, it is necessary to say Y because of a BIOS bug.
1314 config APM_DO_ENABLE
1315 bool "Enable PM at boot time"
1316 ---help---
1317 Enable APM features at boot time. From page 36 of the APM BIOS
1318 specification: "When disabled, the APM BIOS does not automatically
1319 power manage devices, enter the Standby State, enter the Suspend
1320 State, or take power saving steps in response to CPU Idle calls."
1321 This driver will make CPU Idle calls when Linux is idle (unless this
1322 feature is turned off -- see "Do CPU IDLE calls", below). This
1323 should always save battery power, but more complicated APM features
1324 will be dependent on your BIOS implementation. You may need to turn
1325 this option off if your computer hangs at boot time when using APM
1326 support, or if it beeps continuously instead of suspending. Turn
1327 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1328 T400CDT. This is off by default since most machines do fine without
1329 this feature.
1331 config APM_CPU_IDLE
1332 bool "Make CPU Idle calls when idle"
1333 help
1334 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1335 On some machines, this can activate improved power savings, such as
1336 a slowed CPU clock rate, when the machine is idle. These idle calls
1337 are made after the idle loop has run for some length of time (e.g.,
1338 333 mS). On some machines, this will cause a hang at boot time or
1339 whenever the CPU becomes idle. (On machines with more than one CPU,
1340 this option does nothing.)
1342 config APM_DISPLAY_BLANK
1343 bool "Enable console blanking using APM"
1344 help
1345 Enable console blanking using the APM. Some laptops can use this to
1346 turn off the LCD backlight when the screen blanker of the Linux
1347 virtual console blanks the screen. Note that this is only used by
1348 the virtual console screen blanker, and won't turn off the backlight
1349 when using the X Window system. This also doesn't have anything to
1350 do with your VESA-compliant power-saving monitor. Further, this
1351 option doesn't work for all laptops -- it might not turn off your
1352 backlight at all, or it might print a lot of errors to the console,
1353 especially if you are using gpm.
1355 config APM_ALLOW_INTS
1356 bool "Allow interrupts during APM BIOS calls"
1357 help
1358 Normally we disable external interrupts while we are making calls to
1359 the APM BIOS as a measure to lessen the effects of a badly behaving
1360 BIOS implementation. The BIOS should reenable interrupts if it
1361 needs to. Unfortunately, some BIOSes do not -- especially those in
1362 many of the newer IBM Thinkpads. If you experience hangs when you
1363 suspend, try setting this to Y. Otherwise, say N.
1365 config APM_REAL_MODE_POWER_OFF
1366 bool "Use real mode APM BIOS call to power off"
1367 help
1368 Use real mode APM BIOS calls to switch off the computer. This is
1369 a work-around for a number of buggy BIOSes. Switch this option on if
1370 your computer crashes instead of powering off properly.
1372 endif # APM
1374 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1376 source "drivers/cpuidle/Kconfig"
1378 endmenu
1381 menu "Bus options (PCI etc.)"
1383 config PCI
1384 bool "PCI support" if !X86_VISWS
1385 depends on !X86_VOYAGER
1386 default y
1387 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1388 help
1389 Find out whether you have a PCI motherboard. PCI is the name of a
1390 bus system, i.e. the way the CPU talks to the other stuff inside
1391 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1392 VESA. If you have PCI, say Y, otherwise N.
1394 choice
1395 prompt "PCI access mode"
1396 depends on X86_32 && PCI && !X86_VISWS
1397 default PCI_GOANY
1398 ---help---
1399 On PCI systems, the BIOS can be used to detect the PCI devices and
1400 determine their configuration. However, some old PCI motherboards
1401 have BIOS bugs and may crash if this is done. Also, some embedded
1402 PCI-based systems don't have any BIOS at all. Linux can also try to
1403 detect the PCI hardware directly without using the BIOS.
1405 With this option, you can specify how Linux should detect the
1406 PCI devices. If you choose "BIOS", the BIOS will be used,
1407 if you choose "Direct", the BIOS won't be used, and if you
1408 choose "MMConfig", then PCI Express MMCONFIG will be used.
1409 If you choose "Any", the kernel will try MMCONFIG, then the
1410 direct access method and falls back to the BIOS if that doesn't
1411 work. If unsure, go with the default, which is "Any".
1413 config PCI_GOBIOS
1414 bool "BIOS"
1416 config PCI_GOMMCONFIG
1417 bool "MMConfig"
1419 config PCI_GODIRECT
1420 bool "Direct"
1422 config PCI_GOANY
1423 bool "Any"
1425 endchoice
1427 config PCI_BIOS
1428 def_bool y
1429 depends on X86_32 && !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1431 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1432 config PCI_DIRECT
1433 def_bool y
1434 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1436 config PCI_MMCONFIG
1437 def_bool y
1438 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1440 config PCI_DOMAINS
1441 def_bool y
1442 depends on PCI
1444 config PCI_MMCONFIG
1445 bool "Support mmconfig PCI config space access"
1446 depends on X86_64 && PCI && ACPI
1448 config DMAR
1449 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1450 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1451 help
1452 DMA remapping (DMAR) devices support enables independent address
1453 translations for Direct Memory Access (DMA) from devices.
1454 These DMA remapping devices are reported via ACPI tables
1455 and include PCI device scope covered by these DMA
1456 remapping devices.
1458 config DMAR_GFX_WA
1459 def_bool y
1460 prompt "Support for Graphics workaround"
1461 depends on DMAR
1462 help
1463 Current Graphics drivers tend to use physical address
1464 for DMA and avoid using DMA APIs. Setting this config
1465 option permits the IOMMU driver to set a unity map for
1466 all the OS-visible memory. Hence the driver can continue
1467 to use physical addresses for DMA.
1469 config DMAR_FLOPPY_WA
1470 def_bool y
1471 depends on DMAR
1472 help
1473 Floppy disk drivers are know to bypass DMA API calls
1474 thereby failing to work when IOMMU is enabled. This
1475 workaround will setup a 1:1 mapping for the first
1476 16M to make floppy (an ISA device) work.
1478 source "drivers/pci/pcie/Kconfig"
1480 source "drivers/pci/Kconfig"
1482 # x86_64 have no ISA slots, but do have ISA-style DMA.
1483 config ISA_DMA_API
1484 def_bool y
1486 if X86_32
1488 config ISA
1489 bool "ISA support"
1490 depends on !(X86_VOYAGER || X86_VISWS)
1491 help
1492 Find out whether you have ISA slots on your motherboard. ISA is the
1493 name of a bus system, i.e. the way the CPU talks to the other stuff
1494 inside your box. Other bus systems are PCI, EISA, MicroChannel
1495 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1496 newer boards don't support it. If you have ISA, say Y, otherwise N.
1498 config EISA
1499 bool "EISA support"
1500 depends on ISA
1501 ---help---
1502 The Extended Industry Standard Architecture (EISA) bus was
1503 developed as an open alternative to the IBM MicroChannel bus.
1505 The EISA bus provided some of the features of the IBM MicroChannel
1506 bus while maintaining backward compatibility with cards made for
1507 the older ISA bus. The EISA bus saw limited use between 1988 and
1508 1995 when it was made obsolete by the PCI bus.
1510 Say Y here if you are building a kernel for an EISA-based machine.
1512 Otherwise, say N.
1514 source "drivers/eisa/Kconfig"
1516 config MCA
1517 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1518 default y if X86_VOYAGER
1519 help
1520 MicroChannel Architecture is found in some IBM PS/2 machines and
1521 laptops. It is a bus system similar to PCI or ISA. See
1522 <file:Documentation/mca.txt> (and especially the web page given
1523 there) before attempting to build an MCA bus kernel.
1525 source "drivers/mca/Kconfig"
1527 config SCx200
1528 tristate "NatSemi SCx200 support"
1529 depends on !X86_VOYAGER
1530 help
1531 This provides basic support for National Semiconductor's
1532 (now AMD's) Geode processors. The driver probes for the
1533 PCI-IDs of several on-chip devices, so its a good dependency
1534 for other scx200_* drivers.
1536 If compiled as a module, the driver is named scx200.
1538 config SCx200HR_TIMER
1539 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1540 depends on SCx200 && GENERIC_TIME
1541 default y
1542 help
1543 This driver provides a clocksource built upon the on-chip
1544 27MHz high-resolution timer. Its also a workaround for
1545 NSC Geode SC-1100's buggy TSC, which loses time when the
1546 processor goes idle (as is done by the scheduler). The
1547 other workaround is idle=poll boot option.
1549 config GEODE_MFGPT_TIMER
1550 def_bool y
1551 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1552 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1553 help
1554 This driver provides a clock event source based on the MFGPT
1555 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1556 MFGPTs have a better resolution and max interval than the
1557 generic PIT, and are suitable for use as high-res timers.
1559 endif # X86_32
1561 config K8_NB
1562 def_bool y
1563 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1565 source "drivers/pcmcia/Kconfig"
1567 source "drivers/pci/hotplug/Kconfig"
1569 endmenu
1572 menu "Executable file formats / Emulations"
1574 source "fs/Kconfig.binfmt"
1576 config IA32_EMULATION
1577 bool "IA32 Emulation"
1578 depends on X86_64
1579 select COMPAT_BINFMT_ELF
1580 help
1581 Include code to run 32-bit programs under a 64-bit kernel. You should
1582 likely turn this on, unless you're 100% sure that you don't have any
1583 32-bit programs left.
1585 config IA32_AOUT
1586 tristate "IA32 a.out support"
1587 depends on IA32_EMULATION && ARCH_SUPPORTS_AOUT
1588 help
1589 Support old a.out binaries in the 32bit emulation.
1591 config COMPAT
1592 def_bool y
1593 depends on IA32_EMULATION
1595 config COMPAT_FOR_U64_ALIGNMENT
1596 def_bool COMPAT
1597 depends on X86_64
1599 config SYSVIPC_COMPAT
1600 def_bool y
1601 depends on X86_64 && COMPAT && SYSVIPC
1603 endmenu
1606 source "net/Kconfig"
1608 source "drivers/Kconfig"
1610 source "drivers/firmware/Kconfig"
1612 source "fs/Kconfig"
1614 source "arch/x86/Kconfig.debug"
1616 source "security/Kconfig"
1618 source "crypto/Kconfig"
1620 source "arch/x86/kvm/Kconfig"
1622 source "lib/Kconfig"