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
24 config GENERIC_LOCKBREAK
30 config GENERIC_CMOS_UPDATE
33 config CLOCKSOURCE_WATCHDOG
36 config GENERIC_CLOCKEVENTS
39 config GENERIC_CLOCKEVENTS_BROADCAST
41 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
43 config LOCKDEP_SUPPORT
46 config STACKTRACE_SUPPORT
49 config HAVE_LATENCYTOP_SUPPORT
52 config SEMAPHORE_SLEEPERS
67 config GENERIC_ISA_DMA
77 config GENERIC_HWEIGHT
83 config ARCH_MAY_HAVE_PC_FDC
89 config RWSEM_GENERIC_SPINLOCK
92 config RWSEM_XCHGADD_ALGORITHM
95 config ARCH_HAS_ILOG2_U32
98 config ARCH_HAS_ILOG2_U64
101 config GENERIC_CALIBRATE_DELAY
104 config GENERIC_TIME_VSYSCALL
108 config HAVE_SETUP_PER_CPU_AREA
113 config ARCH_HIBERNATION_POSSIBLE
115 depends on !SMP || !X86_VOYAGER
117 config ARCH_SUSPEND_POSSIBLE
119 depends on !X86_VOYAGER
125 config ARCH_POPULATES_NODE_MAP
132 # Use the generic interrupt handling code in kernel/irq/:
133 config GENERIC_HARDIRQS
137 config GENERIC_IRQ_PROBE
141 config GENERIC_PENDING_IRQ
143 depends on GENERIC_HARDIRQS && SMP
148 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
153 depends on X86_32 && SMP
157 depends on X86_64 && SMP
162 depends on (X86_32 && !(X86_VISWS || X86_VOYAGER)) || (X86_64 && !MK8)
165 config X86_BIOS_REBOOT
167 depends on X86_32 && !(X86_VISWS || X86_VOYAGER)
170 config X86_TRAMPOLINE
172 depends on X86_SMP || (X86_VOYAGER && SMP)
177 source "init/Kconfig"
179 menu "Processor type and features"
181 source "kernel/time/Kconfig"
184 bool "Symmetric multi-processing support"
186 This enables support for systems with more than one CPU. If you have
187 a system with only one CPU, like most personal computers, say N. If
188 you have a system with more than one CPU, say Y.
190 If you say N here, the kernel will run on single and multiprocessor
191 machines, but will use only one CPU of a multiprocessor machine. If
192 you say Y here, the kernel will run on many, but not all,
193 singleprocessor machines. On a singleprocessor machine, the kernel
194 will run faster if you say N here.
196 Note that if you say Y here and choose architecture "586" or
197 "Pentium" under "Processor family", the kernel will not work on 486
198 architectures. Similarly, multiprocessor kernels for the "PPro"
199 architecture may not work on all Pentium based boards.
201 People using multiprocessor machines who say Y here should also say
202 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
203 Management" code will be disabled if you say Y here.
205 See also <file:Documentation/i386/IO-APIC.txt>,
206 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
207 <http://www.tldp.org/docs.html#howto>.
209 If you don't know what to do here, say N.
212 prompt "Subarchitecture Type"
218 Choose this option if your computer is a standard PC or compatible.
224 Select this for an AMD Elan processor.
226 Do not use this option for K6/Athlon/Opteron processors!
228 If unsure, choose "PC-compatible" instead.
233 select SMP if !BROKEN
235 Voyager is an MCA-based 32-way capable SMP architecture proprietary
236 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
240 If you do not specifically know you have a Voyager based machine,
241 say N here, otherwise the kernel you build will not be bootable.
244 bool "NUMAQ (IBM/Sequent)"
249 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
250 multiquad box. This changes the way that processors are bootstrapped,
251 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
252 You will need a new lynxer.elf file to flash your firmware with - send
253 email to <Martin.Bligh@us.ibm.com>.
256 bool "Summit/EXA (IBM x440)"
257 depends on X86_32 && SMP
259 This option is needed for IBM systems that use the Summit/EXA chipset.
260 In particular, it is needed for the x440.
262 If you don't have one of these computers, you should say N here.
263 If you want to build a NUMA kernel, you must select ACPI.
266 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
267 depends on X86_32 && SMP
269 This option is needed for the systems that have more than 8 CPUs
270 and if the system is not of any sub-arch type above.
272 If you don't have such a system, you should say N here.
275 bool "SGI 320/540 (Visual Workstation)"
278 The SGI Visual Workstation series is an IA32-based workstation
279 based on SGI systems chips with some legacy PC hardware attached.
281 Say Y here to create a kernel to run on the SGI 320 or 540.
283 A kernel compiled for the Visual Workstation will not run on PCs
284 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
286 config X86_GENERICARCH
287 bool "Generic architecture (Summit, bigsmp, ES7000, default)"
290 This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
291 It is intended for a generic binary kernel.
292 If you want a NUMA kernel, select ACPI. We need SRAT for NUMA.
295 bool "Support for Unisys ES7000 IA32 series"
296 depends on X86_32 && SMP
298 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
299 supposed to run on an IA32-based Unisys ES7000 system.
300 Only choose this option if you have such a system, otherwise you
304 bool "RDC R-321x SoC"
307 select X86_REBOOTFIXUPS
312 This option is needed for RDC R-321x system-on-chip, also known
314 If you don't have one of these chips, you should say N here.
317 bool "Support for ScaleMP vSMP"
318 depends on X86_64 && PCI
320 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
321 supposed to run on these EM64T-based machines. Only choose this option
322 if you have one of these machines.
326 config SCHED_NO_NO_OMIT_FRAME_POINTER
328 prompt "Single-depth WCHAN output"
331 Calculate simpler /proc/<PID>/wchan values. If this option
332 is disabled then wchan values will recurse back to the
333 caller function. This provides more accurate wchan values,
334 at the expense of slightly more scheduling overhead.
336 If in doubt, say "Y".
338 menuconfig PARAVIRT_GUEST
339 bool "Paravirtualized guest support"
341 Say Y here to get to see options related to running Linux under
342 various hypervisors. This option alone does not add any kernel code.
344 If you say N, all options in this submenu will be skipped and disabled.
348 source "arch/x86/xen/Kconfig"
351 bool "VMI Guest support"
354 depends on !(X86_VISWS || X86_VOYAGER)
356 VMI provides a paravirtualized interface to the VMware ESX server
357 (it could be used by other hypervisors in theory too, but is not
358 at the moment), by linking the kernel to a GPL-ed ROM module
359 provided by the hypervisor.
361 source "arch/x86/lguest/Kconfig"
364 bool "Enable paravirtualization code"
365 depends on !(X86_VISWS || X86_VOYAGER)
367 This changes the kernel so it can modify itself when it is run
368 under a hypervisor, potentially improving performance significantly
369 over full virtualization. However, when run without a hypervisor
370 the kernel is theoretically slower and slightly larger.
376 depends on X86_32 && ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
379 config HAVE_ARCH_PARSE_SRAT
383 config X86_SUMMIT_NUMA
385 depends on X86_32 && NUMA && (X86_SUMMIT || X86_GENERICARCH)
387 config X86_CYCLONE_TIMER
389 depends on X86_32 && X86_SUMMIT || X86_GENERICARCH
391 config ES7000_CLUSTERED_APIC
393 depends on SMP && X86_ES7000 && MPENTIUMIII
395 source "arch/x86/Kconfig.cpu"
399 prompt "HPET Timer Support" if X86_32
401 Use the IA-PC HPET (High Precision Event Timer) to manage
402 time in preference to the PIT and RTC, if a HPET is
404 HPET is the next generation timer replacing legacy 8254s.
405 The HPET provides a stable time base on SMP
406 systems, unlike the TSC, but it is more expensive to access,
407 as it is off-chip. You can find the HPET spec at
408 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
410 You can safely choose Y here. However, HPET will only be
411 activated if the platform and the BIOS support this feature.
412 Otherwise the 8254 will be used for timing services.
414 Choose N to continue using the legacy 8254 timer.
416 config HPET_EMULATE_RTC
418 depends on HPET_TIMER && (RTC=y || RTC=m)
420 # Mark as embedded because too many people got it wrong.
421 # The code disables itself when not needed.
423 bool "GART IOMMU support" if EMBEDDED
427 depends on X86_64 && PCI
429 Support for full DMA access of devices with 32bit memory access only
430 on systems with more than 3GB. This is usually needed for USB,
431 sound, many IDE/SATA chipsets and some other devices.
432 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
433 based hardware IOMMU and a software bounce buffer based IOMMU used
434 on Intel systems and as fallback.
435 The code is only active when needed (enough memory and limited
436 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
440 bool "IBM Calgary IOMMU support"
442 depends on X86_64 && PCI && EXPERIMENTAL
444 Support for hardware IOMMUs in IBM's xSeries x366 and x460
445 systems. Needed to run systems with more than 3GB of memory
446 properly with 32-bit PCI devices that do not support DAC
447 (Double Address Cycle). Calgary also supports bus level
448 isolation, where all DMAs pass through the IOMMU. This
449 prevents them from going anywhere except their intended
450 destination. This catches hard-to-find kernel bugs and
451 mis-behaving drivers and devices that do not use the DMA-API
452 properly to set up their DMA buffers. The IOMMU can be
453 turned off at boot time with the iommu=off parameter.
454 Normally the kernel will make the right choice by itself.
457 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
459 prompt "Should Calgary be enabled by default?"
460 depends on CALGARY_IOMMU
462 Should Calgary be enabled by default? if you choose 'y', Calgary
463 will be used (if it exists). If you choose 'n', Calgary will not be
464 used even if it exists. If you choose 'n' and would like to use
465 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
469 def_bool (CALGARY_IOMMU || GART_IOMMU)
471 # need this always selected by IOMMU for the VIA workaround
475 Support for software bounce buffers used on x86-64 systems
476 which don't have a hardware IOMMU (e.g. the current generation
477 of Intel's x86-64 CPUs). Using this PCI devices which can only
478 access 32-bits of memory can be used on systems with more than
479 3 GB of memory. If unsure, say Y.
483 int "Maximum number of CPUs (2-255)"
486 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
489 This allows you to specify the maximum number of CPUs which this
490 kernel will support. The maximum supported value is 255 and the
491 minimum value which makes sense is 2.
493 This is purely to save memory - each supported CPU adds
494 approximately eight kilobytes to the kernel image.
497 bool "SMT (Hyperthreading) scheduler support"
498 depends on (X86_64 && SMP) || (X86_32 && X86_HT)
500 SMT scheduler support improves the CPU scheduler's decision making
501 when dealing with Intel Pentium 4 chips with HyperThreading at a
502 cost of slightly increased overhead in some places. If unsure say
507 prompt "Multi-core scheduler support"
508 depends on (X86_64 && SMP) || (X86_32 && X86_HT)
510 Multi-core scheduler support improves the CPU scheduler's decision
511 making when dealing with multi-core CPU chips at a cost of slightly
512 increased overhead in some places. If unsure say N here.
514 source "kernel/Kconfig.preempt"
517 bool "Local APIC support on uniprocessors"
518 depends on X86_32 && !SMP && !(X86_VISWS || X86_VOYAGER || X86_GENERICARCH)
520 A local APIC (Advanced Programmable Interrupt Controller) is an
521 integrated interrupt controller in the CPU. If you have a single-CPU
522 system which has a processor with a local APIC, you can say Y here to
523 enable and use it. If you say Y here even though your machine doesn't
524 have a local APIC, then the kernel will still run with no slowdown at
525 all. The local APIC supports CPU-generated self-interrupts (timer,
526 performance counters), and the NMI watchdog which detects hard
530 bool "IO-APIC support on uniprocessors"
531 depends on X86_UP_APIC
533 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
534 SMP-capable replacement for PC-style interrupt controllers. Most
535 SMP systems and many recent uniprocessor systems have one.
537 If you have a single-CPU system with an IO-APIC, you can say Y here
538 to use it. If you say Y here even though your machine doesn't have
539 an IO-APIC, then the kernel will still run with no slowdown at all.
541 config X86_LOCAL_APIC
543 depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH))
547 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH))
549 config X86_VISWS_APIC
551 depends on X86_32 && X86_VISWS
554 bool "Machine Check Exception"
555 depends on !X86_VOYAGER
557 Machine Check Exception support allows the processor to notify the
558 kernel if it detects a problem (e.g. overheating, component failure).
559 The action the kernel takes depends on the severity of the problem,
560 ranging from a warning message on the console, to halting the machine.
561 Your processor must be a Pentium or newer to support this - check the
562 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
563 have a design flaw which leads to false MCE events - hence MCE is
564 disabled on all P5 processors, unless explicitly enabled with "mce"
565 as a boot argument. Similarly, if MCE is built in and creates a
566 problem on some new non-standard machine, you can boot with "nomce"
567 to disable it. MCE support simply ignores non-MCE processors like
568 the 386 and 486, so nearly everyone can say Y here.
572 prompt "Intel MCE features"
573 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
575 Additional support for intel specific MCE features such as
580 prompt "AMD MCE features"
581 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
583 Additional support for AMD specific MCE features such as
584 the DRAM Error Threshold.
586 config X86_MCE_NONFATAL
587 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
588 depends on X86_32 && X86_MCE
590 Enabling this feature starts a timer that triggers every 5 seconds which
591 will look at the machine check registers to see if anything happened.
592 Non-fatal problems automatically get corrected (but still logged).
593 Disable this if you don't want to see these messages.
594 Seeing the messages this option prints out may be indicative of dying
595 or out-of-spec (ie, overclocked) hardware.
596 This option only does something on certain CPUs.
597 (AMD Athlon/Duron and Intel Pentium 4)
599 config X86_MCE_P4THERMAL
600 bool "check for P4 thermal throttling interrupt."
601 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP) && !X86_VISWS
603 Enabling this feature will cause a message to be printed when the P4
604 enters thermal throttling.
607 bool "Enable VM86 support" if EMBEDDED
611 This option is required by programs like DOSEMU to run 16-bit legacy
612 code on X86 processors. It also may be needed by software like
613 XFree86 to initialize some video cards via BIOS. Disabling this
614 option saves about 6k.
617 tristate "Toshiba Laptop support"
620 This adds a driver to safely access the System Management Mode of
621 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
622 not work on models with a Phoenix BIOS. The System Management Mode
623 is used to set the BIOS and power saving options on Toshiba portables.
625 For information on utilities to make use of this driver see the
626 Toshiba Linux utilities web site at:
627 <http://www.buzzard.org.uk/toshiba/>.
629 Say Y if you intend to run this kernel on a Toshiba portable.
633 tristate "Dell laptop support"
636 This adds a driver to safely access the System Management Mode
637 of the CPU on the Dell Inspiron 8000. The System Management Mode
638 is used to read cpu temperature and cooling fan status and to
639 control the fans on the I8K portables.
641 This driver has been tested only on the Inspiron 8000 but it may
642 also work with other Dell laptops. You can force loading on other
643 models by passing the parameter `force=1' to the module. Use at
646 For information on utilities to make use of this driver see the
647 I8K Linux utilities web site at:
648 <http://people.debian.org/~dz/i8k/>
650 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
653 config X86_REBOOTFIXUPS
655 prompt "Enable X86 board specific fixups for reboot"
656 depends on X86_32 && X86
658 This enables chipset and/or board specific fixups to be done
659 in order to get reboot to work correctly. This is only needed on
660 some combinations of hardware and BIOS. The symptom, for which
661 this config is intended, is when reboot ends with a stalled/hung
664 Currently, the only fixup is for the Geode machines using
665 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
667 Say Y if you want to enable the fixup. Currently, it's safe to
668 enable this option even if you don't need it.
672 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
675 If you say Y here, you will be able to update the microcode on
676 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
677 Pentium III, Pentium 4, Xeon etc. You will obviously need the
678 actual microcode binary data itself which is not shipped with the
681 For latest news and information on obtaining all the required
682 ingredients for this driver, check:
683 <http://www.urbanmyth.org/microcode/>.
685 To compile this driver as a module, choose M here: the
686 module will be called microcode.
688 config MICROCODE_OLD_INTERFACE
693 tristate "/dev/cpu/*/msr - Model-specific register support"
695 This device gives privileged processes access to the x86
696 Model-Specific Registers (MSRs). It is a character device with
697 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
698 MSR accesses are directed to a specific CPU on multi-processor
702 tristate "/dev/cpu/*/cpuid - CPU information support"
704 This device gives processes access to the x86 CPUID instruction to
705 be executed on a specific processor. It is a character device
706 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
710 prompt "High Memory Support"
711 default HIGHMEM4G if !X86_NUMAQ
712 default HIGHMEM64G if X86_NUMAQ
717 depends on !X86_NUMAQ
719 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
720 However, the address space of 32-bit x86 processors is only 4
721 Gigabytes large. That means that, if you have a large amount of
722 physical memory, not all of it can be "permanently mapped" by the
723 kernel. The physical memory that's not permanently mapped is called
726 If you are compiling a kernel which will never run on a machine with
727 more than 1 Gigabyte total physical RAM, answer "off" here (default
728 choice and suitable for most users). This will result in a "3GB/1GB"
729 split: 3GB are mapped so that each process sees a 3GB virtual memory
730 space and the remaining part of the 4GB virtual memory space is used
731 by the kernel to permanently map as much physical memory as
734 If the machine has between 1 and 4 Gigabytes physical RAM, then
737 If more than 4 Gigabytes is used then answer "64GB" here. This
738 selection turns Intel PAE (Physical Address Extension) mode on.
739 PAE implements 3-level paging on IA32 processors. PAE is fully
740 supported by Linux, PAE mode is implemented on all recent Intel
741 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
742 then the kernel will not boot on CPUs that don't support PAE!
744 The actual amount of total physical memory will either be
745 auto detected or can be forced by using a kernel command line option
746 such as "mem=256M". (Try "man bootparam" or see the documentation of
747 your boot loader (lilo or loadlin) about how to pass options to the
748 kernel at boot time.)
750 If unsure, say "off".
754 depends on !X86_NUMAQ
756 Select this if you have a 32-bit processor and between 1 and 4
757 gigabytes of physical RAM.
761 depends on !M386 && !M486
764 Select this if you have a 32-bit processor and more than 4
765 gigabytes of physical RAM.
770 depends on EXPERIMENTAL
771 prompt "Memory split" if EMBEDDED
775 Select the desired split between kernel and user memory.
777 If the address range available to the kernel is less than the
778 physical memory installed, the remaining memory will be available
779 as "high memory". Accessing high memory is a little more costly
780 than low memory, as it needs to be mapped into the kernel first.
781 Note that increasing the kernel address space limits the range
782 available to user programs, making the address space there
783 tighter. Selecting anything other than the default 3G/1G split
784 will also likely make your kernel incompatible with binary-only
787 If you are not absolutely sure what you are doing, leave this
791 bool "3G/1G user/kernel split"
792 config VMSPLIT_3G_OPT
794 bool "3G/1G user/kernel split (for full 1G low memory)"
796 bool "2G/2G user/kernel split"
797 config VMSPLIT_2G_OPT
799 bool "2G/2G user/kernel split (for full 2G low memory)"
801 bool "1G/3G user/kernel split"
806 default 0xB0000000 if VMSPLIT_3G_OPT
807 default 0x80000000 if VMSPLIT_2G
808 default 0x78000000 if VMSPLIT_2G_OPT
809 default 0x40000000 if VMSPLIT_1G
815 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
819 prompt "PAE (Physical Address Extension) Support"
820 depends on X86_32 && !HIGHMEM4G
821 select RESOURCES_64BIT
823 PAE is required for NX support, and furthermore enables
824 larger swapspace support for non-overcommit purposes. It
825 has the cost of more pagetable lookup overhead, and also
826 consumes more pagetable space per process.
828 # Common NUMA Features
830 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
832 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) && EXPERIMENTAL)
834 default y if (X86_NUMAQ || X86_SUMMIT)
836 Enable NUMA (Non Uniform Memory Access) support.
837 The kernel will try to allocate memory used by a CPU on the
838 local memory controller of the CPU and add some more
839 NUMA awareness to the kernel.
841 For i386 this is currently highly experimental and should be only
842 used for kernel development. It might also cause boot failures.
843 For x86_64 this is recommended on all multiprocessor Opteron systems.
844 If the system is EM64T, you should say N unless your system is
847 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
848 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
852 prompt "Old style AMD Opteron NUMA detection"
853 depends on X86_64 && NUMA && PCI
855 Enable K8 NUMA node topology detection. You should say Y here if
856 you have a multi processor AMD K8 system. This uses an old
857 method to read the NUMA configuration directly from the builtin
858 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
859 instead, which also takes priority if both are compiled in.
861 config X86_64_ACPI_NUMA
863 prompt "ACPI NUMA detection"
864 depends on X86_64 && NUMA && ACPI && PCI
867 Enable ACPI SRAT based node topology detection.
870 bool "NUMA emulation"
871 depends on X86_64 && NUMA
873 Enable NUMA emulation. A flat machine will be split
874 into virtual nodes when booted with "numa=fake=N", where N is the
875 number of nodes. This is only useful for debugging.
880 default "6" if X86_64
881 default "4" if X86_NUMAQ
883 depends on NEED_MULTIPLE_NODES
885 config HAVE_ARCH_BOOTMEM_NODE
887 depends on X86_32 && NUMA
889 config ARCH_HAVE_MEMORY_PRESENT
891 depends on X86_32 && DISCONTIGMEM
893 config NEED_NODE_MEMMAP_SIZE
895 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
897 config HAVE_ARCH_ALLOC_REMAP
899 depends on X86_32 && NUMA
901 config ARCH_FLATMEM_ENABLE
903 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC && !NUMA
905 config ARCH_DISCONTIGMEM_ENABLE
907 depends on NUMA && X86_32
909 config ARCH_DISCONTIGMEM_DEFAULT
911 depends on NUMA && X86_32
913 config ARCH_SPARSEMEM_DEFAULT
917 config ARCH_SPARSEMEM_ENABLE
919 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC)
920 select SPARSEMEM_STATIC if X86_32
921 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
923 config ARCH_SELECT_MEMORY_MODEL
925 depends on ARCH_SPARSEMEM_ENABLE
927 config ARCH_MEMORY_PROBE
929 depends on MEMORY_HOTPLUG
934 bool "Allocate 3rd-level pagetables from highmem"
935 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
937 The VM uses one page table entry for each page of physical memory.
938 For systems with a lot of RAM, this can be wasteful of precious
939 low memory. Setting this option will put user-space page table
940 entries in high memory.
942 config MATH_EMULATION
944 prompt "Math emulation" if X86_32
946 Linux can emulate a math coprocessor (used for floating point
947 operations) if you don't have one. 486DX and Pentium processors have
948 a math coprocessor built in, 486SX and 386 do not, unless you added
949 a 487DX or 387, respectively. (The messages during boot time can
950 give you some hints here ["man dmesg"].) Everyone needs either a
951 coprocessor or this emulation.
953 If you don't have a math coprocessor, you need to say Y here; if you
954 say Y here even though you have a coprocessor, the coprocessor will
955 be used nevertheless. (This behavior can be changed with the kernel
956 command line option "no387", which comes handy if your coprocessor
957 is broken. Try "man bootparam" or see the documentation of your boot
958 loader (lilo or loadlin) about how to pass options to the kernel at
959 boot time.) This means that it is a good idea to say Y here if you
960 intend to use this kernel on different machines.
962 More information about the internals of the Linux math coprocessor
963 emulation can be found in <file:arch/x86/math-emu/README>.
965 If you are not sure, say Y; apart from resulting in a 66 KB bigger
966 kernel, it won't hurt.
969 bool "MTRR (Memory Type Range Register) support"
971 On Intel P6 family processors (Pentium Pro, Pentium II and later)
972 the Memory Type Range Registers (MTRRs) may be used to control
973 processor access to memory ranges. This is most useful if you have
974 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
975 allows bus write transfers to be combined into a larger transfer
976 before bursting over the PCI/AGP bus. This can increase performance
977 of image write operations 2.5 times or more. Saying Y here creates a
978 /proc/mtrr file which may be used to manipulate your processor's
979 MTRRs. Typically the X server should use this.
981 This code has a reasonably generic interface so that similar
982 control registers on other processors can be easily supported
985 The Cyrix 6x86, 6x86MX and M II processors have Address Range
986 Registers (ARRs) which provide a similar functionality to MTRRs. For
987 these, the ARRs are used to emulate the MTRRs.
988 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
989 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
990 write-combining. All of these processors are supported by this code
991 and it makes sense to say Y here if you have one of them.
993 Saying Y here also fixes a problem with buggy SMP BIOSes which only
994 set the MTRRs for the boot CPU and not for the secondary CPUs. This
995 can lead to all sorts of problems, so it's good to say Y here.
997 You can safely say Y even if your machine doesn't have MTRRs, you'll
998 just add about 9 KB to your kernel.
1000 See <file:Documentation/mtrr.txt> for more information.
1004 prompt "EFI runtime service support"
1007 This enables the kernel to use EFI runtime services that are
1008 available (such as the EFI variable services).
1010 This option is only useful on systems that have EFI firmware.
1011 In addition, you should use the latest ELILO loader available
1012 at <http://elilo.sourceforge.net> in order to take advantage
1013 of EFI runtime services. However, even with this option, the
1014 resultant kernel should continue to boot on existing non-EFI
1019 prompt "Enable kernel irq balancing"
1020 depends on X86_32 && SMP && X86_IO_APIC
1022 The default yes will allow the kernel to do irq load balancing.
1023 Saying no will keep the kernel from doing irq load balancing.
1027 prompt "Enable seccomp to safely compute untrusted bytecode"
1030 This kernel feature is useful for number crunching applications
1031 that may need to compute untrusted bytecode during their
1032 execution. By using pipes or other transports made available to
1033 the process as file descriptors supporting the read/write
1034 syscalls, it's possible to isolate those applications in
1035 their own address space using seccomp. Once seccomp is
1036 enabled via /proc/<pid>/seccomp, it cannot be disabled
1037 and the task is only allowed to execute a few safe syscalls
1038 defined by each seccomp mode.
1040 If unsure, say Y. Only embedded should say N here.
1042 config CC_STACKPROTECTOR
1043 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1044 depends on X86_64 && EXPERIMENTAL
1046 This option turns on the -fstack-protector GCC feature. This
1047 feature puts, at the beginning of critical functions, a canary
1048 value on the stack just before the return address, and validates
1049 the value just before actually returning. Stack based buffer
1050 overflows (that need to overwrite this return address) now also
1051 overwrite the canary, which gets detected and the attack is then
1052 neutralized via a kernel panic.
1054 This feature requires gcc version 4.2 or above, or a distribution
1055 gcc with the feature backported. Older versions are automatically
1056 detected and for those versions, this configuration option is ignored.
1058 config CC_STACKPROTECTOR_ALL
1059 bool "Use stack-protector for all functions"
1060 depends on CC_STACKPROTECTOR
1062 Normally, GCC only inserts the canary value protection for
1063 functions that use large-ish on-stack buffers. By enabling
1064 this option, GCC will be asked to do this for ALL functions.
1066 source kernel/Kconfig.hz
1069 bool "kexec system call"
1071 kexec is a system call that implements the ability to shutdown your
1072 current kernel, and to start another kernel. It is like a reboot
1073 but it is independent of the system firmware. And like a reboot
1074 you can start any kernel with it, not just Linux.
1076 The name comes from the similarity to the exec system call.
1078 It is an ongoing process to be certain the hardware in a machine
1079 is properly shutdown, so do not be surprised if this code does not
1080 initially work for you. It may help to enable device hotplugging
1081 support. As of this writing the exact hardware interface is
1082 strongly in flux, so no good recommendation can be made.
1085 bool "kernel crash dumps (EXPERIMENTAL)"
1086 depends on EXPERIMENTAL
1087 depends on X86_64 || (X86_32 && HIGHMEM)
1089 Generate crash dump after being started by kexec.
1090 This should be normally only set in special crash dump kernels
1091 which are loaded in the main kernel with kexec-tools into
1092 a specially reserved region and then later executed after
1093 a crash by kdump/kexec. The crash dump kernel must be compiled
1094 to a memory address not used by the main kernel or BIOS using
1095 PHYSICAL_START, or it must be built as a relocatable image
1096 (CONFIG_RELOCATABLE=y).
1097 For more details see Documentation/kdump/kdump.txt
1099 config PHYSICAL_START
1100 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1101 default "0x1000000" if X86_NUMAQ
1102 default "0x200000" if X86_64
1105 This gives the physical address where the kernel is loaded.
1107 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1108 bzImage will decompress itself to above physical address and
1109 run from there. Otherwise, bzImage will run from the address where
1110 it has been loaded by the boot loader and will ignore above physical
1113 In normal kdump cases one does not have to set/change this option
1114 as now bzImage can be compiled as a completely relocatable image
1115 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1116 address. This option is mainly useful for the folks who don't want
1117 to use a bzImage for capturing the crash dump and want to use a
1118 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1119 to be specifically compiled to run from a specific memory area
1120 (normally a reserved region) and this option comes handy.
1122 So if you are using bzImage for capturing the crash dump, leave
1123 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1124 Otherwise if you plan to use vmlinux for capturing the crash dump
1125 change this value to start of the reserved region (Typically 16MB
1126 0x1000000). In other words, it can be set based on the "X" value as
1127 specified in the "crashkernel=YM@XM" command line boot parameter
1128 passed to the panic-ed kernel. Typically this parameter is set as
1129 crashkernel=64M@16M. Please take a look at
1130 Documentation/kdump/kdump.txt for more details about crash dumps.
1132 Usage of bzImage for capturing the crash dump is recommended as
1133 one does not have to build two kernels. Same kernel can be used
1134 as production kernel and capture kernel. Above option should have
1135 gone away after relocatable bzImage support is introduced. But it
1136 is present because there are users out there who continue to use
1137 vmlinux for dump capture. This option should go away down the
1140 Don't change this unless you know what you are doing.
1143 bool "Build a relocatable kernel (EXPERIMENTAL)"
1144 depends on EXPERIMENTAL
1146 This builds a kernel image that retains relocation information
1147 so it can be loaded someplace besides the default 1MB.
1148 The relocations tend to make the kernel binary about 10% larger,
1149 but are discarded at runtime.
1151 One use is for the kexec on panic case where the recovery kernel
1152 must live at a different physical address than the primary
1155 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1156 it has been loaded at and the compile time physical address
1157 (CONFIG_PHYSICAL_START) is ignored.
1159 config PHYSICAL_ALIGN
1161 prompt "Alignment value to which kernel should be aligned" if X86_32
1162 default "0x100000" if X86_32
1163 default "0x200000" if X86_64
1164 range 0x2000 0x400000
1166 This value puts the alignment restrictions on physical address
1167 where kernel is loaded and run from. Kernel is compiled for an
1168 address which meets above alignment restriction.
1170 If bootloader loads the kernel at a non-aligned address and
1171 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1172 address aligned to above value and run from there.
1174 If bootloader loads the kernel at a non-aligned address and
1175 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1176 load address and decompress itself to the address it has been
1177 compiled for and run from there. The address for which kernel is
1178 compiled already meets above alignment restrictions. Hence the
1179 end result is that kernel runs from a physical address meeting
1180 above alignment restrictions.
1182 Don't change this unless you know what you are doing.
1185 bool "Support for suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
1186 depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
1188 Say Y here to experiment with turning CPUs off and on, and to
1189 enable suspend on SMP systems. CPUs can be controlled through
1190 /sys/devices/system/cpu.
1191 Say N if you want to disable CPU hotplug and don't need to
1196 prompt "Compat VDSO support"
1197 depends on X86_32 || IA32_EMULATION
1199 Map the 32-bit VDSO to the predictable old-style address too.
1201 Say N here if you are running a sufficiently recent glibc
1202 version (2.3.3 or later), to remove the high-mapped
1203 VDSO mapping and to exclusively use the randomized VDSO.
1209 config ARCH_ENABLE_MEMORY_HOTPLUG
1211 depends on X86_64 || (X86_32 && HIGHMEM)
1213 config HAVE_ARCH_EARLY_PFN_TO_NID
1217 menu "Power management options"
1218 depends on !X86_VOYAGER
1220 config ARCH_HIBERNATION_HEADER
1222 depends on X86_64 && HIBERNATION
1224 source "kernel/power/Kconfig"
1226 source "drivers/acpi/Kconfig"
1231 depends on APM || APM_MODULE
1234 tristate "APM (Advanced Power Management) BIOS support"
1235 depends on X86_32 && PM_SLEEP && !X86_VISWS
1237 APM is a BIOS specification for saving power using several different
1238 techniques. This is mostly useful for battery powered laptops with
1239 APM compliant BIOSes. If you say Y here, the system time will be
1240 reset after a RESUME operation, the /proc/apm device will provide
1241 battery status information, and user-space programs will receive
1242 notification of APM "events" (e.g. battery status change).
1244 If you select "Y" here, you can disable actual use of the APM
1245 BIOS by passing the "apm=off" option to the kernel at boot time.
1247 Note that the APM support is almost completely disabled for
1248 machines with more than one CPU.
1250 In order to use APM, you will need supporting software. For location
1251 and more information, read <file:Documentation/pm.txt> and the
1252 Battery Powered Linux mini-HOWTO, available from
1253 <http://www.tldp.org/docs.html#howto>.
1255 This driver does not spin down disk drives (see the hdparm(8)
1256 manpage ("man 8 hdparm") for that), and it doesn't turn off
1257 VESA-compliant "green" monitors.
1259 This driver does not support the TI 4000M TravelMate and the ACER
1260 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1261 desktop machines also don't have compliant BIOSes, and this driver
1262 may cause those machines to panic during the boot phase.
1264 Generally, if you don't have a battery in your machine, there isn't
1265 much point in using this driver and you should say N. If you get
1266 random kernel OOPSes or reboots that don't seem to be related to
1267 anything, try disabling/enabling this option (or disabling/enabling
1270 Some other things you should try when experiencing seemingly random,
1273 1) make sure that you have enough swap space and that it is
1275 2) pass the "no-hlt" option to the kernel
1276 3) switch on floating point emulation in the kernel and pass
1277 the "no387" option to the kernel
1278 4) pass the "floppy=nodma" option to the kernel
1279 5) pass the "mem=4M" option to the kernel (thereby disabling
1280 all but the first 4 MB of RAM)
1281 6) make sure that the CPU is not over clocked.
1282 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1283 8) disable the cache from your BIOS settings
1284 9) install a fan for the video card or exchange video RAM
1285 10) install a better fan for the CPU
1286 11) exchange RAM chips
1287 12) exchange the motherboard.
1289 To compile this driver as a module, choose M here: the
1290 module will be called apm.
1294 config APM_IGNORE_USER_SUSPEND
1295 bool "Ignore USER SUSPEND"
1297 This option will ignore USER SUSPEND requests. On machines with a
1298 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1299 series notebooks, it is necessary to say Y because of a BIOS bug.
1301 config APM_DO_ENABLE
1302 bool "Enable PM at boot time"
1304 Enable APM features at boot time. From page 36 of the APM BIOS
1305 specification: "When disabled, the APM BIOS does not automatically
1306 power manage devices, enter the Standby State, enter the Suspend
1307 State, or take power saving steps in response to CPU Idle calls."
1308 This driver will make CPU Idle calls when Linux is idle (unless this
1309 feature is turned off -- see "Do CPU IDLE calls", below). This
1310 should always save battery power, but more complicated APM features
1311 will be dependent on your BIOS implementation. You may need to turn
1312 this option off if your computer hangs at boot time when using APM
1313 support, or if it beeps continuously instead of suspending. Turn
1314 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1315 T400CDT. This is off by default since most machines do fine without
1319 bool "Make CPU Idle calls when idle"
1321 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1322 On some machines, this can activate improved power savings, such as
1323 a slowed CPU clock rate, when the machine is idle. These idle calls
1324 are made after the idle loop has run for some length of time (e.g.,
1325 333 mS). On some machines, this will cause a hang at boot time or
1326 whenever the CPU becomes idle. (On machines with more than one CPU,
1327 this option does nothing.)
1329 config APM_DISPLAY_BLANK
1330 bool "Enable console blanking using APM"
1332 Enable console blanking using the APM. Some laptops can use this to
1333 turn off the LCD backlight when the screen blanker of the Linux
1334 virtual console blanks the screen. Note that this is only used by
1335 the virtual console screen blanker, and won't turn off the backlight
1336 when using the X Window system. This also doesn't have anything to
1337 do with your VESA-compliant power-saving monitor. Further, this
1338 option doesn't work for all laptops -- it might not turn off your
1339 backlight at all, or it might print a lot of errors to the console,
1340 especially if you are using gpm.
1342 config APM_ALLOW_INTS
1343 bool "Allow interrupts during APM BIOS calls"
1345 Normally we disable external interrupts while we are making calls to
1346 the APM BIOS as a measure to lessen the effects of a badly behaving
1347 BIOS implementation. The BIOS should reenable interrupts if it
1348 needs to. Unfortunately, some BIOSes do not -- especially those in
1349 many of the newer IBM Thinkpads. If you experience hangs when you
1350 suspend, try setting this to Y. Otherwise, say N.
1352 config APM_REAL_MODE_POWER_OFF
1353 bool "Use real mode APM BIOS call to power off"
1355 Use real mode APM BIOS calls to switch off the computer. This is
1356 a work-around for a number of buggy BIOSes. Switch this option on if
1357 your computer crashes instead of powering off properly.
1361 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1363 source "drivers/cpuidle/Kconfig"
1368 menu "Bus options (PCI etc.)"
1371 bool "PCI support" if !X86_VISWS
1372 depends on !X86_VOYAGER
1374 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1376 Find out whether you have a PCI motherboard. PCI is the name of a
1377 bus system, i.e. the way the CPU talks to the other stuff inside
1378 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1379 VESA. If you have PCI, say Y, otherwise N.
1382 prompt "PCI access mode"
1383 depends on X86_32 && PCI && !X86_VISWS
1386 On PCI systems, the BIOS can be used to detect the PCI devices and
1387 determine their configuration. However, some old PCI motherboards
1388 have BIOS bugs and may crash if this is done. Also, some embedded
1389 PCI-based systems don't have any BIOS at all. Linux can also try to
1390 detect the PCI hardware directly without using the BIOS.
1392 With this option, you can specify how Linux should detect the
1393 PCI devices. If you choose "BIOS", the BIOS will be used,
1394 if you choose "Direct", the BIOS won't be used, and if you
1395 choose "MMConfig", then PCI Express MMCONFIG will be used.
1396 If you choose "Any", the kernel will try MMCONFIG, then the
1397 direct access method and falls back to the BIOS if that doesn't
1398 work. If unsure, go with the default, which is "Any".
1403 config PCI_GOMMCONFIG
1416 depends on X86_32 && !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1418 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1421 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1425 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1432 bool "Support mmconfig PCI config space access"
1433 depends on X86_64 && PCI && ACPI
1436 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1437 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1439 DMA remapping (DMAR) devices support enables independent address
1440 translations for Direct Memory Access (DMA) from devices.
1441 These DMA remapping devices are reported via ACPI tables
1442 and include PCI device scope covered by these DMA
1447 prompt "Support for Graphics workaround"
1450 Current Graphics drivers tend to use physical address
1451 for DMA and avoid using DMA APIs. Setting this config
1452 option permits the IOMMU driver to set a unity map for
1453 all the OS-visible memory. Hence the driver can continue
1454 to use physical addresses for DMA.
1456 config DMAR_FLOPPY_WA
1460 Floppy disk drivers are know to bypass DMA API calls
1461 thereby failing to work when IOMMU is enabled. This
1462 workaround will setup a 1:1 mapping for the first
1463 16M to make floppy (an ISA device) work.
1465 source "drivers/pci/pcie/Kconfig"
1467 source "drivers/pci/Kconfig"
1469 # x86_64 have no ISA slots, but do have ISA-style DMA.
1477 depends on !(X86_VOYAGER || X86_VISWS)
1479 Find out whether you have ISA slots on your motherboard. ISA is the
1480 name of a bus system, i.e. the way the CPU talks to the other stuff
1481 inside your box. Other bus systems are PCI, EISA, MicroChannel
1482 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1483 newer boards don't support it. If you have ISA, say Y, otherwise N.
1489 The Extended Industry Standard Architecture (EISA) bus was
1490 developed as an open alternative to the IBM MicroChannel bus.
1492 The EISA bus provided some of the features of the IBM MicroChannel
1493 bus while maintaining backward compatibility with cards made for
1494 the older ISA bus. The EISA bus saw limited use between 1988 and
1495 1995 when it was made obsolete by the PCI bus.
1497 Say Y here if you are building a kernel for an EISA-based machine.
1501 source "drivers/eisa/Kconfig"
1504 bool "MCA support" if !(X86_VISWS || X86_VOYAGER)
1505 default y if X86_VOYAGER
1507 MicroChannel Architecture is found in some IBM PS/2 machines and
1508 laptops. It is a bus system similar to PCI or ISA. See
1509 <file:Documentation/mca.txt> (and especially the web page given
1510 there) before attempting to build an MCA bus kernel.
1512 source "drivers/mca/Kconfig"
1515 tristate "NatSemi SCx200 support"
1516 depends on !X86_VOYAGER
1518 This provides basic support for National Semiconductor's
1519 (now AMD's) Geode processors. The driver probes for the
1520 PCI-IDs of several on-chip devices, so its a good dependency
1521 for other scx200_* drivers.
1523 If compiled as a module, the driver is named scx200.
1525 config SCx200HR_TIMER
1526 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1527 depends on SCx200 && GENERIC_TIME
1530 This driver provides a clocksource built upon the on-chip
1531 27MHz high-resolution timer. Its also a workaround for
1532 NSC Geode SC-1100's buggy TSC, which loses time when the
1533 processor goes idle (as is done by the scheduler). The
1534 other workaround is idle=poll boot option.
1536 config GEODE_MFGPT_TIMER
1538 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1539 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1541 This driver provides a clock event source based on the MFGPT
1542 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1543 MFGPTs have a better resolution and max interval than the
1544 generic PIT, and are suitable for use as high-res timers.
1550 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1552 source "drivers/pcmcia/Kconfig"
1554 source "drivers/pci/hotplug/Kconfig"
1559 menu "Executable file formats / Emulations"
1561 source "fs/Kconfig.binfmt"
1563 config IA32_EMULATION
1564 bool "IA32 Emulation"
1566 select COMPAT_BINFMT_ELF
1568 Include code to run 32-bit programs under a 64-bit kernel. You should
1569 likely turn this on, unless you're 100% sure that you don't have any
1570 32-bit programs left.
1573 tristate "IA32 a.out support"
1574 depends on IA32_EMULATION
1576 Support old a.out binaries in the 32bit emulation.
1580 depends on IA32_EMULATION
1582 config COMPAT_FOR_U64_ALIGNMENT
1586 config SYSVIPC_COMPAT
1588 depends on X86_64 && COMPAT && SYSVIPC
1593 source "net/Kconfig"
1595 source "drivers/Kconfig"
1597 source "drivers/firmware/Kconfig"
1601 source "arch/x86/Kconfig.debug"
1603 source "security/Kconfig"
1605 source "crypto/Kconfig"
1607 source "arch/x86/kvm/Kconfig"
1609 source "lib/Kconfig"
projects / linux-2.6 / blob