2 mainmenu "Linux Kernel Configuration for x86"
6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
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
21 select HAVE_AOUT if X86_32
22 select HAVE_UNSTABLE_SCHED_CLOCK
25 select HAVE_IOREMAP_PROT
27 select ARCH_WANT_OPTIONAL_GPIOLIB
28 select HAVE_KRETPROBES
29 select HAVE_FTRACE_MCOUNT_RECORD
30 select HAVE_DYNAMIC_FTRACE
31 select HAVE_FUNCTION_TRACER
32 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
33 select HAVE_ARCH_KGDB if !X86_VOYAGER
34 select HAVE_ARCH_TRACEHOOK
35 select HAVE_GENERIC_DMA_COHERENT if X86_32
36 select HAVE_EFFICIENT_UNALIGNED_ACCESS
40 default "arch/x86/configs/i386_defconfig" if X86_32
41 default "arch/x86/configs/x86_64_defconfig" if X86_64
46 config GENERIC_CMOS_UPDATE
49 config CLOCKSOURCE_WATCHDOG
52 config GENERIC_CLOCKEVENTS
55 config GENERIC_CLOCKEVENTS_BROADCAST
57 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
59 config LOCKDEP_SUPPORT
62 config STACKTRACE_SUPPORT
65 config HAVE_LATENCYTOP_SUPPORT
68 config FAST_CMPXCHG_LOCAL
81 config GENERIC_ISA_DMA
91 config GENERIC_HWEIGHT
97 config ARCH_MAY_HAVE_PC_FDC
100 config RWSEM_GENERIC_SPINLOCK
103 config RWSEM_XCHGADD_ALGORITHM
106 config ARCH_HAS_CPU_IDLE_WAIT
109 config GENERIC_CALIBRATE_DELAY
112 config GENERIC_TIME_VSYSCALL
116 config ARCH_HAS_CPU_RELAX
119 config ARCH_HAS_DEFAULT_IDLE
122 config ARCH_HAS_CACHE_LINE_SIZE
125 config HAVE_SETUP_PER_CPU_AREA
126 def_bool X86_64_SMP || (X86_SMP && !X86_VOYAGER)
128 config HAVE_CPUMASK_OF_CPU_MAP
131 config ARCH_HIBERNATION_POSSIBLE
133 depends on !SMP || !X86_VOYAGER
135 config ARCH_SUSPEND_POSSIBLE
137 depends on !X86_VOYAGER
143 config ARCH_POPULATES_NODE_MAP
150 config ARCH_SUPPORTS_OPTIMIZED_INLINING
153 # Use the generic interrupt handling code in kernel/irq/:
154 config GENERIC_HARDIRQS
158 config GENERIC_IRQ_PROBE
162 config GENERIC_PENDING_IRQ
164 depends on GENERIC_HARDIRQS && SMP
169 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
172 config USE_GENERIC_SMP_HELPERS
178 depends on X86_32 && SMP
182 depends on X86_64 && SMP
187 depends on (X86_32 && !X86_VOYAGER) || X86_64
190 config X86_BIOS_REBOOT
192 depends on !X86_VOYAGER
195 config X86_TRAMPOLINE
197 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
202 source "init/Kconfig"
203 source "kernel/Kconfig.freezer"
205 menu "Processor type and features"
207 source "kernel/time/Kconfig"
210 bool "Symmetric multi-processing support"
212 This enables support for systems with more than one CPU. If you have
213 a system with only one CPU, like most personal computers, say N. If
214 you have a system with more than one CPU, say Y.
216 If you say N here, the kernel will run on single and multiprocessor
217 machines, but will use only one CPU of a multiprocessor machine. If
218 you say Y here, the kernel will run on many, but not all,
219 singleprocessor machines. On a singleprocessor machine, the kernel
220 will run faster if you say N here.
222 Note that if you say Y here and choose architecture "586" or
223 "Pentium" under "Processor family", the kernel will not work on 486
224 architectures. Similarly, multiprocessor kernels for the "PPro"
225 architecture may not work on all Pentium based boards.
227 People using multiprocessor machines who say Y here should also say
228 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
229 Management" code will be disabled if you say Y here.
231 See also <file:Documentation/i386/IO-APIC.txt>,
232 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
233 <http://www.tldp.org/docs.html#howto>.
235 If you don't know what to do here, say N.
237 config X86_HAS_BOOT_CPU_ID
239 depends on X86_VOYAGER
242 bool "Support sparse irq numbering"
243 depends on (PCI_MSI || HT_IRQ) && SMP
246 This enables support for sparse irq, esp for msi/msi-x. You may need
247 if you have lots of cards supports msi-x installed.
249 If you don't know what to do here, say Y.
251 config NUMA_MIGRATE_IRQ_DESC
252 bool "Move irq desc when changing irq smp_affinity"
253 depends on SPARSE_IRQ && SMP
256 This enables moving irq_desc to cpu/node that irq will use handled.
258 If you don't know what to do here, say N.
260 config X86_FIND_SMP_CONFIG
262 depends on X86_MPPARSE || X86_VOYAGER
267 bool "Enable MPS table"
268 depends on X86_LOCAL_APIC
270 For old smp systems that do not have proper acpi support. Newer systems
271 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
277 depends on X86_LOCAL_APIC
281 prompt "Subarchitecture Type"
287 Choose this option if your computer is a standard PC or compatible.
293 Select this for an AMD Elan processor.
295 Do not use this option for K6/Athlon/Opteron processors!
297 If unsure, choose "PC-compatible" instead.
301 depends on X86_32 && (SMP || BROKEN) && !PCI
303 Voyager is an MCA-based 32-way capable SMP architecture proprietary
304 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
308 If you do not specifically know you have a Voyager based machine,
309 say N here, otherwise the kernel you build will not be bootable.
311 config X86_GENERICARCH
312 bool "Generic architecture"
315 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
316 subarchitectures. It is intended for a generic binary kernel.
317 if you select them all, kernel will probe it one by one. and will
323 bool "NUMAQ (IBM/Sequent)"
324 depends on SMP && X86_32 && PCI && X86_MPPARSE
327 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
328 NUMA multiquad box. This changes the way that processors are
329 bootstrapped, and uses Clustered Logical APIC addressing mode instead
330 of Flat Logical. You will need a new lynxer.elf file to flash your
331 firmware with - send email to <Martin.Bligh@us.ibm.com>.
334 bool "Summit/EXA (IBM x440)"
335 depends on X86_32 && SMP
337 This option is needed for IBM systems that use the Summit/EXA chipset.
338 In particular, it is needed for the x440.
341 bool "Support for Unisys ES7000 IA32 series"
342 depends on X86_32 && SMP
344 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
345 supposed to run on an IA32-based Unisys ES7000 system.
348 bool "Support for big SMP systems with more than 8 CPUs"
349 depends on X86_32 && SMP
351 This option is needed for the systems that have more than 8 CPUs
352 and if the system is not of any sub-arch type above.
357 bool "Support for ScaleMP vSMP"
359 depends on X86_64 && PCI
361 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
362 supposed to run on these EM64T-based machines. Only choose this option
363 if you have one of these machines.
368 bool "SGI 320/540 (Visual Workstation)"
369 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
371 The SGI Visual Workstation series is an IA32-based workstation
372 based on SGI systems chips with some legacy PC hardware attached.
374 Say Y here to create a kernel to run on the SGI 320 or 540.
376 A kernel compiled for the Visual Workstation will run on general
377 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
380 bool "RDC R-321x SoC"
383 select X86_REBOOTFIXUPS
385 This option is needed for RDC R-321x system-on-chip, also known
387 If you don't have one of these chips, you should say N here.
389 config SCHED_NO_NO_OMIT_FRAME_POINTER
391 prompt "Single-depth WCHAN output"
394 Calculate simpler /proc/<PID>/wchan values. If this option
395 is disabled then wchan values will recurse back to the
396 caller function. This provides more accurate wchan values,
397 at the expense of slightly more scheduling overhead.
399 If in doubt, say "Y".
401 menuconfig PARAVIRT_GUEST
402 bool "Paravirtualized guest support"
404 Say Y here to get to see options related to running Linux under
405 various hypervisors. This option alone does not add any kernel code.
407 If you say N, all options in this submenu will be skipped and disabled.
411 source "arch/x86/xen/Kconfig"
414 bool "VMI Guest support"
417 depends on !X86_VOYAGER
419 VMI provides a paravirtualized interface to the VMware ESX server
420 (it could be used by other hypervisors in theory too, but is not
421 at the moment), by linking the kernel to a GPL-ed ROM module
422 provided by the hypervisor.
425 bool "KVM paravirtualized clock"
427 select PARAVIRT_CLOCK
428 depends on !X86_VOYAGER
430 Turning on this option will allow you to run a paravirtualized clock
431 when running over the KVM hypervisor. Instead of relying on a PIT
432 (or probably other) emulation by the underlying device model, the host
433 provides the guest with timing infrastructure such as time of day, and
437 bool "KVM Guest support"
439 depends on !X86_VOYAGER
441 This option enables various optimizations for running under the KVM
444 source "arch/x86/lguest/Kconfig"
447 bool "Enable paravirtualization code"
448 depends on !X86_VOYAGER
450 This changes the kernel so it can modify itself when it is run
451 under a hypervisor, potentially improving performance significantly
452 over full virtualization. However, when run without a hypervisor
453 the kernel is theoretically slower and slightly larger.
455 config PARAVIRT_CLOCK
461 config PARAVIRT_DEBUG
462 bool "paravirt-ops debugging"
463 depends on PARAVIRT && DEBUG_KERNEL
465 Enable to debug paravirt_ops internals. Specifically, BUG if
466 a paravirt_op is missing when it is called.
471 This option adds a kernel parameter 'memtest', which allows memtest
473 memtest=0, mean disabled; -- default
474 memtest=1, mean do 1 test pattern;
476 memtest=4, mean do 4 test patterns.
477 If you are unsure how to answer this question, answer N.
479 config X86_SUMMIT_NUMA
481 depends on X86_32 && NUMA && X86_GENERICARCH
483 config X86_CYCLONE_TIMER
485 depends on X86_GENERICARCH
487 config ES7000_CLUSTERED_APIC
489 depends on SMP && X86_ES7000 && MPENTIUMIII
491 source "arch/x86/Kconfig.cpu"
495 prompt "HPET Timer Support" if X86_32
497 Use the IA-PC HPET (High Precision Event Timer) to manage
498 time in preference to the PIT and RTC, if a HPET is
500 HPET is the next generation timer replacing legacy 8254s.
501 The HPET provides a stable time base on SMP
502 systems, unlike the TSC, but it is more expensive to access,
503 as it is off-chip. You can find the HPET spec at
504 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
506 You can safely choose Y here. However, HPET will only be
507 activated if the platform and the BIOS support this feature.
508 Otherwise the 8254 will be used for timing services.
510 Choose N to continue using the legacy 8254 timer.
512 config HPET_EMULATE_RTC
514 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
516 # Mark as embedded because too many people got it wrong.
517 # The code disables itself when not needed.
520 bool "Enable DMI scanning" if EMBEDDED
522 Enabled scanning of DMI to identify machine quirks. Say Y
523 here unless you have verified that your setup is not
524 affected by entries in the DMI blacklist. Required by PNP
528 bool "GART IOMMU support" if EMBEDDED
532 depends on X86_64 && PCI
534 Support for full DMA access of devices with 32bit memory access only
535 on systems with more than 3GB. This is usually needed for USB,
536 sound, many IDE/SATA chipsets and some other devices.
537 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
538 based hardware IOMMU and a software bounce buffer based IOMMU used
539 on Intel systems and as fallback.
540 The code is only active when needed (enough memory and limited
541 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
545 bool "IBM Calgary IOMMU support"
547 depends on X86_64 && PCI && EXPERIMENTAL
549 Support for hardware IOMMUs in IBM's xSeries x366 and x460
550 systems. Needed to run systems with more than 3GB of memory
551 properly with 32-bit PCI devices that do not support DAC
552 (Double Address Cycle). Calgary also supports bus level
553 isolation, where all DMAs pass through the IOMMU. This
554 prevents them from going anywhere except their intended
555 destination. This catches hard-to-find kernel bugs and
556 mis-behaving drivers and devices that do not use the DMA-API
557 properly to set up their DMA buffers. The IOMMU can be
558 turned off at boot time with the iommu=off parameter.
559 Normally the kernel will make the right choice by itself.
562 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
564 prompt "Should Calgary be enabled by default?"
565 depends on CALGARY_IOMMU
567 Should Calgary be enabled by default? if you choose 'y', Calgary
568 will be used (if it exists). If you choose 'n', Calgary will not be
569 used even if it exists. If you choose 'n' and would like to use
570 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
574 bool "AMD IOMMU support"
577 depends on X86_64 && PCI && ACPI
579 With this option you can enable support for AMD IOMMU hardware in
580 your system. An IOMMU is a hardware component which provides
581 remapping of DMA memory accesses from devices. With an AMD IOMMU you
582 can isolate the the DMA memory of different devices and protect the
583 system from misbehaving device drivers or hardware.
585 You can find out if your system has an AMD IOMMU if you look into
586 your BIOS for an option to enable it or if you have an IVRS ACPI
589 # need this always selected by IOMMU for the VIA workaround
593 Support for software bounce buffers used on x86-64 systems
594 which don't have a hardware IOMMU (e.g. the current generation
595 of Intel's x86-64 CPUs). Using this PCI devices which can only
596 access 32-bits of memory can be used on systems with more than
597 3 GB of memory. If unsure, say Y.
600 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
603 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
604 depends on X86_64 && SMP && BROKEN
607 Configure maximum number of CPUS and NUMA Nodes for this architecture.
611 int "Maximum number of CPUs (2-512)" if !MAXSMP
614 default "4096" if MAXSMP
615 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
618 This allows you to specify the maximum number of CPUs which this
619 kernel will support. The maximum supported value is 512 and the
620 minimum value which makes sense is 2.
622 This is purely to save memory - each supported CPU adds
623 approximately eight kilobytes to the kernel image.
626 bool "SMT (Hyperthreading) scheduler support"
629 SMT scheduler support improves the CPU scheduler's decision making
630 when dealing with Intel Pentium 4 chips with HyperThreading at a
631 cost of slightly increased overhead in some places. If unsure say
636 prompt "Multi-core scheduler support"
639 Multi-core scheduler support improves the CPU scheduler's decision
640 making when dealing with multi-core CPU chips at a cost of slightly
641 increased overhead in some places. If unsure say N here.
643 source "kernel/Kconfig.preempt"
646 bool "Local APIC support on uniprocessors"
647 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
649 A local APIC (Advanced Programmable Interrupt Controller) is an
650 integrated interrupt controller in the CPU. If you have a single-CPU
651 system which has a processor with a local APIC, you can say Y here to
652 enable and use it. If you say Y here even though your machine doesn't
653 have a local APIC, then the kernel will still run with no slowdown at
654 all. The local APIC supports CPU-generated self-interrupts (timer,
655 performance counters), and the NMI watchdog which detects hard
659 bool "IO-APIC support on uniprocessors"
660 depends on X86_UP_APIC
662 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
663 SMP-capable replacement for PC-style interrupt controllers. Most
664 SMP systems and many recent uniprocessor systems have one.
666 If you have a single-CPU system with an IO-APIC, you can say Y here
667 to use it. If you say Y here even though your machine doesn't have
668 an IO-APIC, then the kernel will still run with no slowdown at all.
670 config X86_LOCAL_APIC
672 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
676 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
678 config X86_VISWS_APIC
680 depends on X86_32 && X86_VISWS
683 bool "Machine Check Exception"
684 depends on !X86_VOYAGER
686 Machine Check Exception support allows the processor to notify the
687 kernel if it detects a problem (e.g. overheating, component failure).
688 The action the kernel takes depends on the severity of the problem,
689 ranging from a warning message on the console, to halting the machine.
690 Your processor must be a Pentium or newer to support this - check the
691 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
692 have a design flaw which leads to false MCE events - hence MCE is
693 disabled on all P5 processors, unless explicitly enabled with "mce"
694 as a boot argument. Similarly, if MCE is built in and creates a
695 problem on some new non-standard machine, you can boot with "nomce"
696 to disable it. MCE support simply ignores non-MCE processors like
697 the 386 and 486, so nearly everyone can say Y here.
701 prompt "Intel MCE features"
702 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
704 Additional support for intel specific MCE features such as
709 prompt "AMD MCE features"
710 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
712 Additional support for AMD specific MCE features such as
713 the DRAM Error Threshold.
715 config X86_MCE_NONFATAL
716 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
717 depends on X86_32 && X86_MCE
719 Enabling this feature starts a timer that triggers every 5 seconds which
720 will look at the machine check registers to see if anything happened.
721 Non-fatal problems automatically get corrected (but still logged).
722 Disable this if you don't want to see these messages.
723 Seeing the messages this option prints out may be indicative of dying
724 or out-of-spec (ie, overclocked) hardware.
725 This option only does something on certain CPUs.
726 (AMD Athlon/Duron and Intel Pentium 4)
728 config X86_MCE_P4THERMAL
729 bool "check for P4 thermal throttling interrupt."
730 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
732 Enabling this feature will cause a message to be printed when the P4
733 enters thermal throttling.
736 bool "Enable VM86 support" if EMBEDDED
740 This option is required by programs like DOSEMU to run 16-bit legacy
741 code on X86 processors. It also may be needed by software like
742 XFree86 to initialize some video cards via BIOS. Disabling this
743 option saves about 6k.
746 tristate "Toshiba Laptop support"
749 This adds a driver to safely access the System Management Mode of
750 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
751 not work on models with a Phoenix BIOS. The System Management Mode
752 is used to set the BIOS and power saving options on Toshiba portables.
754 For information on utilities to make use of this driver see the
755 Toshiba Linux utilities web site at:
756 <http://www.buzzard.org.uk/toshiba/>.
758 Say Y if you intend to run this kernel on a Toshiba portable.
762 tristate "Dell laptop support"
764 This adds a driver to safely access the System Management Mode
765 of the CPU on the Dell Inspiron 8000. The System Management Mode
766 is used to read cpu temperature and cooling fan status and to
767 control the fans on the I8K portables.
769 This driver has been tested only on the Inspiron 8000 but it may
770 also work with other Dell laptops. You can force loading on other
771 models by passing the parameter `force=1' to the module. Use at
774 For information on utilities to make use of this driver see the
775 I8K Linux utilities web site at:
776 <http://people.debian.org/~dz/i8k/>
778 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
781 config X86_REBOOTFIXUPS
782 bool "Enable X86 board specific fixups for reboot"
785 This enables chipset and/or board specific fixups to be done
786 in order to get reboot to work correctly. This is only needed on
787 some combinations of hardware and BIOS. The symptom, for which
788 this config is intended, is when reboot ends with a stalled/hung
791 Currently, the only fixup is for the Geode machines using
792 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
794 Say Y if you want to enable the fixup. Currently, it's safe to
795 enable this option even if you don't need it.
799 tristate "/dev/cpu/microcode - microcode support"
802 If you say Y here, you will be able to update the microcode on
803 certain Intel and AMD processors. The Intel support is for the
804 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
805 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
806 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
807 You will obviously need the actual microcode binary data itself
808 which is not shipped with the Linux kernel.
810 This option selects the general module only, you need to select
811 at least one vendor specific module as well.
813 To compile this driver as a module, choose M here: the
814 module will be called microcode.
816 config MICROCODE_INTEL
817 bool "Intel microcode patch loading support"
822 This options enables microcode patch loading support for Intel
825 For latest news and information on obtaining all the required
826 Intel ingredients for this driver, check:
827 <http://www.urbanmyth.org/microcode/>.
830 bool "AMD microcode patch loading support"
834 If you select this option, microcode patch loading support for AMD
835 processors will be enabled.
837 config MICROCODE_OLD_INTERFACE
842 tristate "/dev/cpu/*/msr - Model-specific register support"
844 This device gives privileged processes access to the x86
845 Model-Specific Registers (MSRs). It is a character device with
846 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
847 MSR accesses are directed to a specific CPU on multi-processor
851 tristate "/dev/cpu/*/cpuid - CPU information support"
853 This device gives processes access to the x86 CPUID instruction to
854 be executed on a specific processor. It is a character device
855 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
859 prompt "High Memory Support"
860 default HIGHMEM4G if !X86_NUMAQ
861 default HIGHMEM64G if X86_NUMAQ
866 depends on !X86_NUMAQ
868 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
869 However, the address space of 32-bit x86 processors is only 4
870 Gigabytes large. That means that, if you have a large amount of
871 physical memory, not all of it can be "permanently mapped" by the
872 kernel. The physical memory that's not permanently mapped is called
875 If you are compiling a kernel which will never run on a machine with
876 more than 1 Gigabyte total physical RAM, answer "off" here (default
877 choice and suitable for most users). This will result in a "3GB/1GB"
878 split: 3GB are mapped so that each process sees a 3GB virtual memory
879 space and the remaining part of the 4GB virtual memory space is used
880 by the kernel to permanently map as much physical memory as
883 If the machine has between 1 and 4 Gigabytes physical RAM, then
886 If more than 4 Gigabytes is used then answer "64GB" here. This
887 selection turns Intel PAE (Physical Address Extension) mode on.
888 PAE implements 3-level paging on IA32 processors. PAE is fully
889 supported by Linux, PAE mode is implemented on all recent Intel
890 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
891 then the kernel will not boot on CPUs that don't support PAE!
893 The actual amount of total physical memory will either be
894 auto detected or can be forced by using a kernel command line option
895 such as "mem=256M". (Try "man bootparam" or see the documentation of
896 your boot loader (lilo or loadlin) about how to pass options to the
897 kernel at boot time.)
899 If unsure, say "off".
903 depends on !X86_NUMAQ
905 Select this if you have a 32-bit processor and between 1 and 4
906 gigabytes of physical RAM.
910 depends on !M386 && !M486
913 Select this if you have a 32-bit processor and more than 4
914 gigabytes of physical RAM.
919 depends on EXPERIMENTAL
920 prompt "Memory split" if EMBEDDED
924 Select the desired split between kernel and user memory.
926 If the address range available to the kernel is less than the
927 physical memory installed, the remaining memory will be available
928 as "high memory". Accessing high memory is a little more costly
929 than low memory, as it needs to be mapped into the kernel first.
930 Note that increasing the kernel address space limits the range
931 available to user programs, making the address space there
932 tighter. Selecting anything other than the default 3G/1G split
933 will also likely make your kernel incompatible with binary-only
936 If you are not absolutely sure what you are doing, leave this
940 bool "3G/1G user/kernel split"
941 config VMSPLIT_3G_OPT
943 bool "3G/1G user/kernel split (for full 1G low memory)"
945 bool "2G/2G user/kernel split"
946 config VMSPLIT_2G_OPT
948 bool "2G/2G user/kernel split (for full 2G low memory)"
950 bool "1G/3G user/kernel split"
955 default 0xB0000000 if VMSPLIT_3G_OPT
956 default 0x80000000 if VMSPLIT_2G
957 default 0x78000000 if VMSPLIT_2G_OPT
958 default 0x40000000 if VMSPLIT_1G
964 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
967 bool "PAE (Physical Address Extension) Support"
968 depends on X86_32 && !HIGHMEM4G
970 PAE is required for NX support, and furthermore enables
971 larger swapspace support for non-overcommit purposes. It
972 has the cost of more pagetable lookup overhead, and also
973 consumes more pagetable space per process.
975 config ARCH_PHYS_ADDR_T_64BIT
976 def_bool X86_64 || X86_PAE
978 # Common NUMA Features
980 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
982 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
984 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
986 Enable NUMA (Non Uniform Memory Access) support.
987 The kernel will try to allocate memory used by a CPU on the
988 local memory controller of the CPU and add some more
989 NUMA awareness to the kernel.
991 For 32-bit this is currently highly experimental and should be only
992 used for kernel development. It might also cause boot failures.
993 For 64-bit this is recommended on all multiprocessor Opteron systems.
994 If the system is EM64T, you should say N unless your system is
997 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
998 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1002 prompt "Old style AMD Opteron NUMA detection"
1003 depends on X86_64 && NUMA && PCI
1005 Enable K8 NUMA node topology detection. You should say Y here if
1006 you have a multi processor AMD K8 system. This uses an old
1007 method to read the NUMA configuration directly from the builtin
1008 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1009 instead, which also takes priority if both are compiled in.
1011 config X86_64_ACPI_NUMA
1013 prompt "ACPI NUMA detection"
1014 depends on X86_64 && NUMA && ACPI && PCI
1017 Enable ACPI SRAT based node topology detection.
1019 # Some NUMA nodes have memory ranges that span
1020 # other nodes. Even though a pfn is valid and
1021 # between a node's start and end pfns, it may not
1022 # reside on that node. See memmap_init_zone()
1024 config NODES_SPAN_OTHER_NODES
1026 depends on X86_64_ACPI_NUMA
1029 bool "NUMA emulation"
1030 depends on X86_64 && NUMA
1032 Enable NUMA emulation. A flat machine will be split
1033 into virtual nodes when booted with "numa=fake=N", where N is the
1034 number of nodes. This is only useful for debugging.
1037 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1039 default "9" if MAXSMP
1040 default "6" if X86_64
1041 default "4" if X86_NUMAQ
1043 depends on NEED_MULTIPLE_NODES
1045 Specify the maximum number of NUMA Nodes available on the target
1046 system. Increases memory reserved to accomodate various tables.
1048 config HAVE_ARCH_BOOTMEM_NODE
1050 depends on X86_32 && NUMA
1052 config ARCH_HAVE_MEMORY_PRESENT
1054 depends on X86_32 && DISCONTIGMEM
1056 config NEED_NODE_MEMMAP_SIZE
1058 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1060 config HAVE_ARCH_ALLOC_REMAP
1062 depends on X86_32 && NUMA
1064 config ARCH_FLATMEM_ENABLE
1066 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1068 config ARCH_DISCONTIGMEM_ENABLE
1070 depends on NUMA && X86_32
1072 config ARCH_DISCONTIGMEM_DEFAULT
1074 depends on NUMA && X86_32
1076 config ARCH_SPARSEMEM_DEFAULT
1080 config ARCH_SPARSEMEM_ENABLE
1082 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH
1083 select SPARSEMEM_STATIC if X86_32
1084 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1086 config ARCH_SELECT_MEMORY_MODEL
1088 depends on ARCH_SPARSEMEM_ENABLE
1090 config ARCH_MEMORY_PROBE
1092 depends on MEMORY_HOTPLUG
1097 bool "Allocate 3rd-level pagetables from highmem"
1098 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1100 The VM uses one page table entry for each page of physical memory.
1101 For systems with a lot of RAM, this can be wasteful of precious
1102 low memory. Setting this option will put user-space page table
1103 entries in high memory.
1105 config X86_CHECK_BIOS_CORRUPTION
1106 bool "Check for low memory corruption"
1108 Periodically check for memory corruption in low memory, which
1109 is suspected to be caused by BIOS. Even when enabled in the
1110 configuration, it is disabled at runtime. Enable it by
1111 setting "memory_corruption_check=1" on the kernel command
1112 line. By default it scans the low 64k of memory every 60
1113 seconds; see the memory_corruption_check_size and
1114 memory_corruption_check_period parameters in
1115 Documentation/kernel-parameters.txt to adjust this.
1117 When enabled with the default parameters, this option has
1118 almost no overhead, as it reserves a relatively small amount
1119 of memory and scans it infrequently. It both detects corruption
1120 and prevents it from affecting the running system.
1122 It is, however, intended as a diagnostic tool; if repeatable
1123 BIOS-originated corruption always affects the same memory,
1124 you can use memmap= to prevent the kernel from using that
1127 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1128 bool "Set the default setting of memory_corruption_check"
1129 depends on X86_CHECK_BIOS_CORRUPTION
1132 Set whether the default state of memory_corruption_check is
1135 config X86_RESERVE_LOW_64K
1136 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1139 Reserve the first 64K of physical RAM on BIOSes that are known
1140 to potentially corrupt that memory range. A numbers of BIOSes are
1141 known to utilize this area during suspend/resume, so it must not
1142 be used by the kernel.
1144 Set this to N if you are absolutely sure that you trust the BIOS
1145 to get all its memory reservations and usages right.
1147 If you have doubts about the BIOS (e.g. suspend/resume does not
1148 work or there's kernel crashes after certain hardware hotplug
1149 events) and it's not AMI or Phoenix, then you might want to enable
1150 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1151 corruption patterns.
1155 config MATH_EMULATION
1157 prompt "Math emulation" if X86_32
1159 Linux can emulate a math coprocessor (used for floating point
1160 operations) if you don't have one. 486DX and Pentium processors have
1161 a math coprocessor built in, 486SX and 386 do not, unless you added
1162 a 487DX or 387, respectively. (The messages during boot time can
1163 give you some hints here ["man dmesg"].) Everyone needs either a
1164 coprocessor or this emulation.
1166 If you don't have a math coprocessor, you need to say Y here; if you
1167 say Y here even though you have a coprocessor, the coprocessor will
1168 be used nevertheless. (This behavior can be changed with the kernel
1169 command line option "no387", which comes handy if your coprocessor
1170 is broken. Try "man bootparam" or see the documentation of your boot
1171 loader (lilo or loadlin) about how to pass options to the kernel at
1172 boot time.) This means that it is a good idea to say Y here if you
1173 intend to use this kernel on different machines.
1175 More information about the internals of the Linux math coprocessor
1176 emulation can be found in <file:arch/x86/math-emu/README>.
1178 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1179 kernel, it won't hurt.
1182 bool "MTRR (Memory Type Range Register) support"
1184 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1185 the Memory Type Range Registers (MTRRs) may be used to control
1186 processor access to memory ranges. This is most useful if you have
1187 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1188 allows bus write transfers to be combined into a larger transfer
1189 before bursting over the PCI/AGP bus. This can increase performance
1190 of image write operations 2.5 times or more. Saying Y here creates a
1191 /proc/mtrr file which may be used to manipulate your processor's
1192 MTRRs. Typically the X server should use this.
1194 This code has a reasonably generic interface so that similar
1195 control registers on other processors can be easily supported
1198 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1199 Registers (ARRs) which provide a similar functionality to MTRRs. For
1200 these, the ARRs are used to emulate the MTRRs.
1201 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1202 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1203 write-combining. All of these processors are supported by this code
1204 and it makes sense to say Y here if you have one of them.
1206 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1207 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1208 can lead to all sorts of problems, so it's good to say Y here.
1210 You can safely say Y even if your machine doesn't have MTRRs, you'll
1211 just add about 9 KB to your kernel.
1213 See <file:Documentation/x86/mtrr.txt> for more information.
1215 config MTRR_SANITIZER
1217 prompt "MTRR cleanup support"
1220 Convert MTRR layout from continuous to discrete, so X drivers can
1221 add writeback entries.
1223 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1224 The largest mtrr entry size for a continous block can be set with
1229 config MTRR_SANITIZER_ENABLE_DEFAULT
1230 int "MTRR cleanup enable value (0-1)"
1233 depends on MTRR_SANITIZER
1235 Enable mtrr cleanup default value
1237 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1238 int "MTRR cleanup spare reg num (0-7)"
1241 depends on MTRR_SANITIZER
1243 mtrr cleanup spare entries default, it can be changed via
1244 mtrr_spare_reg_nr=N on the kernel command line.
1248 prompt "x86 PAT support"
1251 Use PAT attributes to setup page level cache control.
1253 PATs are the modern equivalents of MTRRs and are much more
1254 flexible than MTRRs.
1256 Say N here if you see bootup problems (boot crash, boot hang,
1257 spontaneous reboots) or a non-working video driver.
1262 bool "EFI runtime service support"
1265 This enables the kernel to use EFI runtime services that are
1266 available (such as the EFI variable services).
1268 This option is only useful on systems that have EFI firmware.
1269 In addition, you should use the latest ELILO loader available
1270 at <http://elilo.sourceforge.net> in order to take advantage
1271 of EFI runtime services. However, even with this option, the
1272 resultant kernel should continue to boot on existing non-EFI
1277 prompt "Enable seccomp to safely compute untrusted bytecode"
1279 This kernel feature is useful for number crunching applications
1280 that may need to compute untrusted bytecode during their
1281 execution. By using pipes or other transports made available to
1282 the process as file descriptors supporting the read/write
1283 syscalls, it's possible to isolate those applications in
1284 their own address space using seccomp. Once seccomp is
1285 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1286 and the task is only allowed to execute a few safe syscalls
1287 defined by each seccomp mode.
1289 If unsure, say Y. Only embedded should say N here.
1291 config CC_STACKPROTECTOR
1292 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1293 depends on X86_64 && EXPERIMENTAL && BROKEN
1295 This option turns on the -fstack-protector GCC feature. This
1296 feature puts, at the beginning of critical functions, a canary
1297 value on the stack just before the return address, and validates
1298 the value just before actually returning. Stack based buffer
1299 overflows (that need to overwrite this return address) now also
1300 overwrite the canary, which gets detected and the attack is then
1301 neutralized via a kernel panic.
1303 This feature requires gcc version 4.2 or above, or a distribution
1304 gcc with the feature backported. Older versions are automatically
1305 detected and for those versions, this configuration option is ignored.
1307 config CC_STACKPROTECTOR_ALL
1308 bool "Use stack-protector for all functions"
1309 depends on CC_STACKPROTECTOR
1311 Normally, GCC only inserts the canary value protection for
1312 functions that use large-ish on-stack buffers. By enabling
1313 this option, GCC will be asked to do this for ALL functions.
1315 source kernel/Kconfig.hz
1318 bool "kexec system call"
1319 depends on X86_BIOS_REBOOT
1321 kexec is a system call that implements the ability to shutdown your
1322 current kernel, and to start another kernel. It is like a reboot
1323 but it is independent of the system firmware. And like a reboot
1324 you can start any kernel with it, not just Linux.
1326 The name comes from the similarity to the exec system call.
1328 It is an ongoing process to be certain the hardware in a machine
1329 is properly shutdown, so do not be surprised if this code does not
1330 initially work for you. It may help to enable device hotplugging
1331 support. As of this writing the exact hardware interface is
1332 strongly in flux, so no good recommendation can be made.
1335 bool "kernel crash dumps"
1336 depends on X86_64 || (X86_32 && HIGHMEM)
1338 Generate crash dump after being started by kexec.
1339 This should be normally only set in special crash dump kernels
1340 which are loaded in the main kernel with kexec-tools into
1341 a specially reserved region and then later executed after
1342 a crash by kdump/kexec. The crash dump kernel must be compiled
1343 to a memory address not used by the main kernel or BIOS using
1344 PHYSICAL_START, or it must be built as a relocatable image
1345 (CONFIG_RELOCATABLE=y).
1346 For more details see Documentation/kdump/kdump.txt
1349 bool "kexec jump (EXPERIMENTAL)"
1350 depends on EXPERIMENTAL
1351 depends on KEXEC && HIBERNATION && X86_32
1353 Jump between original kernel and kexeced kernel and invoke
1354 code in physical address mode via KEXEC
1356 config PHYSICAL_START
1357 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1358 default "0x1000000" if X86_NUMAQ
1359 default "0x200000" if X86_64
1362 This gives the physical address where the kernel is loaded.
1364 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1365 bzImage will decompress itself to above physical address and
1366 run from there. Otherwise, bzImage will run from the address where
1367 it has been loaded by the boot loader and will ignore above physical
1370 In normal kdump cases one does not have to set/change this option
1371 as now bzImage can be compiled as a completely relocatable image
1372 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1373 address. This option is mainly useful for the folks who don't want
1374 to use a bzImage for capturing the crash dump and want to use a
1375 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1376 to be specifically compiled to run from a specific memory area
1377 (normally a reserved region) and this option comes handy.
1379 So if you are using bzImage for capturing the crash dump, leave
1380 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1381 Otherwise if you plan to use vmlinux for capturing the crash dump
1382 change this value to start of the reserved region (Typically 16MB
1383 0x1000000). In other words, it can be set based on the "X" value as
1384 specified in the "crashkernel=YM@XM" command line boot parameter
1385 passed to the panic-ed kernel. Typically this parameter is set as
1386 crashkernel=64M@16M. Please take a look at
1387 Documentation/kdump/kdump.txt for more details about crash dumps.
1389 Usage of bzImage for capturing the crash dump is recommended as
1390 one does not have to build two kernels. Same kernel can be used
1391 as production kernel and capture kernel. Above option should have
1392 gone away after relocatable bzImage support is introduced. But it
1393 is present because there are users out there who continue to use
1394 vmlinux for dump capture. This option should go away down the
1397 Don't change this unless you know what you are doing.
1400 bool "Build a relocatable kernel (EXPERIMENTAL)"
1401 depends on EXPERIMENTAL
1403 This builds a kernel image that retains relocation information
1404 so it can be loaded someplace besides the default 1MB.
1405 The relocations tend to make the kernel binary about 10% larger,
1406 but are discarded at runtime.
1408 One use is for the kexec on panic case where the recovery kernel
1409 must live at a different physical address than the primary
1412 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1413 it has been loaded at and the compile time physical address
1414 (CONFIG_PHYSICAL_START) is ignored.
1416 config PHYSICAL_ALIGN
1418 prompt "Alignment value to which kernel should be aligned" if X86_32
1419 default "0x100000" if X86_32
1420 default "0x200000" if X86_64
1421 range 0x2000 0x400000
1423 This value puts the alignment restrictions on physical address
1424 where kernel is loaded and run from. Kernel is compiled for an
1425 address which meets above alignment restriction.
1427 If bootloader loads the kernel at a non-aligned address and
1428 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1429 address aligned to above value and run from there.
1431 If bootloader loads the kernel at a non-aligned address and
1432 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1433 load address and decompress itself to the address it has been
1434 compiled for and run from there. The address for which kernel is
1435 compiled already meets above alignment restrictions. Hence the
1436 end result is that kernel runs from a physical address meeting
1437 above alignment restrictions.
1439 Don't change this unless you know what you are doing.
1442 bool "Support for hot-pluggable CPUs"
1443 depends on SMP && HOTPLUG && !X86_VOYAGER
1445 Say Y here to allow turning CPUs off and on. CPUs can be
1446 controlled through /sys/devices/system/cpu.
1447 ( Note: power management support will enable this option
1448 automatically on SMP systems. )
1449 Say N if you want to disable CPU hotplug.
1453 prompt "Compat VDSO support"
1454 depends on X86_32 || IA32_EMULATION
1456 Map the 32-bit VDSO to the predictable old-style address too.
1458 Say N here if you are running a sufficiently recent glibc
1459 version (2.3.3 or later), to remove the high-mapped
1460 VDSO mapping and to exclusively use the randomized VDSO.
1465 bool "Built-in kernel command line"
1468 Allow for specifying boot arguments to the kernel at
1469 build time. On some systems (e.g. embedded ones), it is
1470 necessary or convenient to provide some or all of the
1471 kernel boot arguments with the kernel itself (that is,
1472 to not rely on the boot loader to provide them.)
1474 To compile command line arguments into the kernel,
1475 set this option to 'Y', then fill in the
1476 the boot arguments in CONFIG_CMDLINE.
1478 Systems with fully functional boot loaders (i.e. non-embedded)
1479 should leave this option set to 'N'.
1482 string "Built-in kernel command string"
1483 depends on CMDLINE_BOOL
1486 Enter arguments here that should be compiled into the kernel
1487 image and used at boot time. If the boot loader provides a
1488 command line at boot time, it is appended to this string to
1489 form the full kernel command line, when the system boots.
1491 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1492 change this behavior.
1494 In most cases, the command line (whether built-in or provided
1495 by the boot loader) should specify the device for the root
1498 config CMDLINE_OVERRIDE
1499 bool "Built-in command line overrides boot loader arguments"
1501 depends on CMDLINE_BOOL
1503 Set this option to 'Y' to have the kernel ignore the boot loader
1504 command line, and use ONLY the built-in command line.
1506 This is used to work around broken boot loaders. This should
1507 be set to 'N' under normal conditions.
1511 config ARCH_ENABLE_MEMORY_HOTPLUG
1513 depends on X86_64 || (X86_32 && HIGHMEM)
1515 config HAVE_ARCH_EARLY_PFN_TO_NID
1519 menu "Power management and ACPI options"
1520 depends on !X86_VOYAGER
1522 config ARCH_HIBERNATION_HEADER
1524 depends on X86_64 && HIBERNATION
1526 source "kernel/power/Kconfig"
1528 source "drivers/acpi/Kconfig"
1533 depends on APM || APM_MODULE
1536 tristate "APM (Advanced Power Management) BIOS support"
1537 depends on X86_32 && PM_SLEEP
1539 APM is a BIOS specification for saving power using several different
1540 techniques. This is mostly useful for battery powered laptops with
1541 APM compliant BIOSes. If you say Y here, the system time will be
1542 reset after a RESUME operation, the /proc/apm device will provide
1543 battery status information, and user-space programs will receive
1544 notification of APM "events" (e.g. battery status change).
1546 If you select "Y" here, you can disable actual use of the APM
1547 BIOS by passing the "apm=off" option to the kernel at boot time.
1549 Note that the APM support is almost completely disabled for
1550 machines with more than one CPU.
1552 In order to use APM, you will need supporting software. For location
1553 and more information, read <file:Documentation/power/pm.txt> and the
1554 Battery Powered Linux mini-HOWTO, available from
1555 <http://www.tldp.org/docs.html#howto>.
1557 This driver does not spin down disk drives (see the hdparm(8)
1558 manpage ("man 8 hdparm") for that), and it doesn't turn off
1559 VESA-compliant "green" monitors.
1561 This driver does not support the TI 4000M TravelMate and the ACER
1562 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1563 desktop machines also don't have compliant BIOSes, and this driver
1564 may cause those machines to panic during the boot phase.
1566 Generally, if you don't have a battery in your machine, there isn't
1567 much point in using this driver and you should say N. If you get
1568 random kernel OOPSes or reboots that don't seem to be related to
1569 anything, try disabling/enabling this option (or disabling/enabling
1572 Some other things you should try when experiencing seemingly random,
1575 1) make sure that you have enough swap space and that it is
1577 2) pass the "no-hlt" option to the kernel
1578 3) switch on floating point emulation in the kernel and pass
1579 the "no387" option to the kernel
1580 4) pass the "floppy=nodma" option to the kernel
1581 5) pass the "mem=4M" option to the kernel (thereby disabling
1582 all but the first 4 MB of RAM)
1583 6) make sure that the CPU is not over clocked.
1584 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1585 8) disable the cache from your BIOS settings
1586 9) install a fan for the video card or exchange video RAM
1587 10) install a better fan for the CPU
1588 11) exchange RAM chips
1589 12) exchange the motherboard.
1591 To compile this driver as a module, choose M here: the
1592 module will be called apm.
1596 config APM_IGNORE_USER_SUSPEND
1597 bool "Ignore USER SUSPEND"
1599 This option will ignore USER SUSPEND requests. On machines with a
1600 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1601 series notebooks, it is necessary to say Y because of a BIOS bug.
1603 config APM_DO_ENABLE
1604 bool "Enable PM at boot time"
1606 Enable APM features at boot time. From page 36 of the APM BIOS
1607 specification: "When disabled, the APM BIOS does not automatically
1608 power manage devices, enter the Standby State, enter the Suspend
1609 State, or take power saving steps in response to CPU Idle calls."
1610 This driver will make CPU Idle calls when Linux is idle (unless this
1611 feature is turned off -- see "Do CPU IDLE calls", below). This
1612 should always save battery power, but more complicated APM features
1613 will be dependent on your BIOS implementation. You may need to turn
1614 this option off if your computer hangs at boot time when using APM
1615 support, or if it beeps continuously instead of suspending. Turn
1616 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1617 T400CDT. This is off by default since most machines do fine without
1621 bool "Make CPU Idle calls when idle"
1623 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1624 On some machines, this can activate improved power savings, such as
1625 a slowed CPU clock rate, when the machine is idle. These idle calls
1626 are made after the idle loop has run for some length of time (e.g.,
1627 333 mS). On some machines, this will cause a hang at boot time or
1628 whenever the CPU becomes idle. (On machines with more than one CPU,
1629 this option does nothing.)
1631 config APM_DISPLAY_BLANK
1632 bool "Enable console blanking using APM"
1634 Enable console blanking using the APM. Some laptops can use this to
1635 turn off the LCD backlight when the screen blanker of the Linux
1636 virtual console blanks the screen. Note that this is only used by
1637 the virtual console screen blanker, and won't turn off the backlight
1638 when using the X Window system. This also doesn't have anything to
1639 do with your VESA-compliant power-saving monitor. Further, this
1640 option doesn't work for all laptops -- it might not turn off your
1641 backlight at all, or it might print a lot of errors to the console,
1642 especially if you are using gpm.
1644 config APM_ALLOW_INTS
1645 bool "Allow interrupts during APM BIOS calls"
1647 Normally we disable external interrupts while we are making calls to
1648 the APM BIOS as a measure to lessen the effects of a badly behaving
1649 BIOS implementation. The BIOS should reenable interrupts if it
1650 needs to. Unfortunately, some BIOSes do not -- especially those in
1651 many of the newer IBM Thinkpads. If you experience hangs when you
1652 suspend, try setting this to Y. Otherwise, say N.
1654 config APM_REAL_MODE_POWER_OFF
1655 bool "Use real mode APM BIOS call to power off"
1657 Use real mode APM BIOS calls to switch off the computer. This is
1658 a work-around for a number of buggy BIOSes. Switch this option on if
1659 your computer crashes instead of powering off properly.
1663 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1665 source "drivers/cpuidle/Kconfig"
1667 source "drivers/idle/Kconfig"
1672 menu "Bus options (PCI etc.)"
1677 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1679 Find out whether you have a PCI motherboard. PCI is the name of a
1680 bus system, i.e. the way the CPU talks to the other stuff inside
1681 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1682 VESA. If you have PCI, say Y, otherwise N.
1685 prompt "PCI access mode"
1686 depends on X86_32 && PCI
1689 On PCI systems, the BIOS can be used to detect the PCI devices and
1690 determine their configuration. However, some old PCI motherboards
1691 have BIOS bugs and may crash if this is done. Also, some embedded
1692 PCI-based systems don't have any BIOS at all. Linux can also try to
1693 detect the PCI hardware directly without using the BIOS.
1695 With this option, you can specify how Linux should detect the
1696 PCI devices. If you choose "BIOS", the BIOS will be used,
1697 if you choose "Direct", the BIOS won't be used, and if you
1698 choose "MMConfig", then PCI Express MMCONFIG will be used.
1699 If you choose "Any", the kernel will try MMCONFIG, then the
1700 direct access method and falls back to the BIOS if that doesn't
1701 work. If unsure, go with the default, which is "Any".
1706 config PCI_GOMMCONFIG
1723 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1725 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1728 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1732 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1736 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1743 bool "Support mmconfig PCI config space access"
1744 depends on X86_64 && PCI && ACPI
1747 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1748 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1750 DMA remapping (DMAR) devices support enables independent address
1751 translations for Direct Memory Access (DMA) from devices.
1752 These DMA remapping devices are reported via ACPI tables
1753 and include PCI device scope covered by these DMA
1758 prompt "Support for Graphics workaround"
1761 Current Graphics drivers tend to use physical address
1762 for DMA and avoid using DMA APIs. Setting this config
1763 option permits the IOMMU driver to set a unity map for
1764 all the OS-visible memory. Hence the driver can continue
1765 to use physical addresses for DMA.
1767 config DMAR_FLOPPY_WA
1771 Floppy disk drivers are know to bypass DMA API calls
1772 thereby failing to work when IOMMU is enabled. This
1773 workaround will setup a 1:1 mapping for the first
1774 16M to make floppy (an ISA device) work.
1777 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1778 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1780 Supports Interrupt remapping for IO-APIC and MSI devices.
1781 To use x2apic mode in the CPU's which support x2APIC enhancements or
1782 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1784 source "drivers/pci/pcie/Kconfig"
1786 source "drivers/pci/Kconfig"
1788 # x86_64 have no ISA slots, but do have ISA-style DMA.
1796 depends on !X86_VOYAGER
1798 Find out whether you have ISA slots on your motherboard. ISA is the
1799 name of a bus system, i.e. the way the CPU talks to the other stuff
1800 inside your box. Other bus systems are PCI, EISA, MicroChannel
1801 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1802 newer boards don't support it. If you have ISA, say Y, otherwise N.
1808 The Extended Industry Standard Architecture (EISA) bus was
1809 developed as an open alternative to the IBM MicroChannel bus.
1811 The EISA bus provided some of the features of the IBM MicroChannel
1812 bus while maintaining backward compatibility with cards made for
1813 the older ISA bus. The EISA bus saw limited use between 1988 and
1814 1995 when it was made obsolete by the PCI bus.
1816 Say Y here if you are building a kernel for an EISA-based machine.
1820 source "drivers/eisa/Kconfig"
1823 bool "MCA support" if !X86_VOYAGER
1824 default y if X86_VOYAGER
1826 MicroChannel Architecture is found in some IBM PS/2 machines and
1827 laptops. It is a bus system similar to PCI or ISA. See
1828 <file:Documentation/mca.txt> (and especially the web page given
1829 there) before attempting to build an MCA bus kernel.
1831 source "drivers/mca/Kconfig"
1834 tristate "NatSemi SCx200 support"
1835 depends on !X86_VOYAGER
1837 This provides basic support for National Semiconductor's
1838 (now AMD's) Geode processors. The driver probes for the
1839 PCI-IDs of several on-chip devices, so its a good dependency
1840 for other scx200_* drivers.
1842 If compiled as a module, the driver is named scx200.
1844 config SCx200HR_TIMER
1845 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1846 depends on SCx200 && GENERIC_TIME
1849 This driver provides a clocksource built upon the on-chip
1850 27MHz high-resolution timer. Its also a workaround for
1851 NSC Geode SC-1100's buggy TSC, which loses time when the
1852 processor goes idle (as is done by the scheduler). The
1853 other workaround is idle=poll boot option.
1855 config GEODE_MFGPT_TIMER
1857 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1858 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1860 This driver provides a clock event source based on the MFGPT
1861 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1862 MFGPTs have a better resolution and max interval than the
1863 generic PIT, and are suitable for use as high-res timers.
1866 bool "One Laptop Per Child support"
1869 Add support for detecting the unique features of the OLPC
1876 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1878 source "drivers/pcmcia/Kconfig"
1880 source "drivers/pci/hotplug/Kconfig"
1885 menu "Executable file formats / Emulations"
1887 source "fs/Kconfig.binfmt"
1889 config IA32_EMULATION
1890 bool "IA32 Emulation"
1892 select COMPAT_BINFMT_ELF
1894 Include code to run 32-bit programs under a 64-bit kernel. You should
1895 likely turn this on, unless you're 100% sure that you don't have any
1896 32-bit programs left.
1899 tristate "IA32 a.out support"
1900 depends on IA32_EMULATION
1902 Support old a.out binaries in the 32bit emulation.
1906 depends on IA32_EMULATION
1908 config COMPAT_FOR_U64_ALIGNMENT
1912 config SYSVIPC_COMPAT
1914 depends on COMPAT && SYSVIPC
1919 config HAVE_ATOMIC_IOMAP
1923 source "net/Kconfig"
1925 source "drivers/Kconfig"
1927 source "drivers/firmware/Kconfig"
1931 source "arch/x86/Kconfig.debug"
1933 source "security/Kconfig"
1935 source "crypto/Kconfig"
1937 source "arch/x86/kvm/Kconfig"
1939 source "lib/Kconfig"
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