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
24 select HAVE_UNSTABLE_SCHED_CLOCK
27 select HAVE_IOREMAP_PROT
29 select ARCH_WANT_OPTIONAL_GPIOLIB
30 select ARCH_WANT_FRAME_POINTERS
31 select HAVE_KRETPROBES
32 select HAVE_FTRACE_MCOUNT_RECORD
33 select HAVE_DYNAMIC_FTRACE
34 select HAVE_FUNCTION_TRACER
35 select HAVE_FUNCTION_GRAPH_TRACER
36 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
39 select HAVE_ARCH_TRACEHOOK
40 select HAVE_GENERIC_DMA_COHERENT if X86_32
41 select HAVE_EFFICIENT_UNALIGNED_ACCESS
42 select USER_STACKTRACE_SUPPORT
43 select HAVE_KERNEL_GZIP
44 select HAVE_KERNEL_BZIP2
45 select HAVE_KERNEL_LZMA
49 default "arch/x86/configs/i386_defconfig" if X86_32
50 default "arch/x86/configs/x86_64_defconfig" if X86_64
55 config GENERIC_CMOS_UPDATE
58 config CLOCKSOURCE_WATCHDOG
61 config GENERIC_CLOCKEVENTS
64 config GENERIC_CLOCKEVENTS_BROADCAST
66 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
68 config LOCKDEP_SUPPORT
71 config STACKTRACE_SUPPORT
74 config HAVE_LATENCYTOP_SUPPORT
77 config FAST_CMPXCHG_LOCAL
90 config GENERIC_ISA_DMA
99 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
101 config GENERIC_BUG_RELATIVE_POINTERS
104 config GENERIC_HWEIGHT
110 config ARCH_MAY_HAVE_PC_FDC
113 config RWSEM_GENERIC_SPINLOCK
116 config RWSEM_XCHGADD_ALGORITHM
119 config ARCH_HAS_CPU_IDLE_WAIT
122 config GENERIC_CALIBRATE_DELAY
125 config GENERIC_TIME_VSYSCALL
129 config ARCH_HAS_CPU_RELAX
132 config ARCH_HAS_DEFAULT_IDLE
135 config ARCH_HAS_CACHE_LINE_SIZE
138 config HAVE_SETUP_PER_CPU_AREA
141 config HAVE_CPUMASK_OF_CPU_MAP
144 config ARCH_HIBERNATION_POSSIBLE
147 config ARCH_SUSPEND_POSSIBLE
154 config ARCH_POPULATES_NODE_MAP
161 config ARCH_SUPPORTS_OPTIMIZED_INLINING
164 # Use the generic interrupt handling code in kernel/irq/:
165 config GENERIC_HARDIRQS
169 config GENERIC_IRQ_PROBE
173 config GENERIC_PENDING_IRQ
175 depends on GENERIC_HARDIRQS && SMP
178 config USE_GENERIC_SMP_HELPERS
184 depends on X86_32 && SMP
188 depends on X86_64 && SMP
195 config X86_TRAMPOLINE
197 depends on SMP || (64BIT && ACPI_SLEEP)
200 config X86_32_LAZY_GS
202 depends on X86_32 && !CC_STACKPROTECTOR
206 source "init/Kconfig"
207 source "kernel/Kconfig.freezer"
209 menu "Processor type and features"
211 source "kernel/time/Kconfig"
214 bool "Symmetric multi-processing support"
216 This enables support for systems with more than one CPU. If you have
217 a system with only one CPU, like most personal computers, say N. If
218 you have a system with more than one CPU, say Y.
220 If you say N here, the kernel will run on single and multiprocessor
221 machines, but will use only one CPU of a multiprocessor machine. If
222 you say Y here, the kernel will run on many, but not all,
223 singleprocessor machines. On a singleprocessor machine, the kernel
224 will run faster if you say N here.
226 Note that if you say Y here and choose architecture "586" or
227 "Pentium" under "Processor family", the kernel will not work on 486
228 architectures. Similarly, multiprocessor kernels for the "PPro"
229 architecture may not work on all Pentium based boards.
231 People using multiprocessor machines who say Y here should also say
232 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
233 Management" code will be disabled if you say Y here.
235 See also <file:Documentation/i386/IO-APIC.txt>,
236 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
237 <http://www.tldp.org/docs.html#howto>.
239 If you don't know what to do here, say N.
242 bool "Support x2apic"
243 depends on X86_LOCAL_APIC && X86_64
245 This enables x2apic support on CPUs that have this feature.
247 This allows 32-bit apic IDs (so it can support very large systems),
248 and accesses the local apic via MSRs not via mmio.
250 ( On certain CPU models you may need to enable INTR_REMAP too,
251 to get functional x2apic mode. )
253 If you don't know what to do here, say N.
256 bool "Support sparse irq numbering"
257 depends on PCI_MSI || HT_IRQ
259 This enables support for sparse irqs. This is useful for distro
260 kernels that want to define a high CONFIG_NR_CPUS value but still
261 want to have low kernel memory footprint on smaller machines.
263 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
264 out the irq_desc[] array in a more NUMA-friendly way. )
266 If you don't know what to do here, say N.
268 config NUMA_MIGRATE_IRQ_DESC
269 bool "Move irq desc when changing irq smp_affinity"
270 depends on SPARSE_IRQ && NUMA
273 This enables moving irq_desc to cpu/node that irq will use handled.
275 If you don't know what to do here, say N.
278 bool "Enable MPS table" if ACPI
280 depends on X86_LOCAL_APIC
282 For old smp systems that do not have proper acpi support. Newer systems
283 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
286 bool "Support for big SMP systems with more than 8 CPUs"
287 depends on X86_32 && SMP
289 This option is needed for the systems that have more than 8 CPUs
292 config X86_EXTENDED_PLATFORM
293 bool "Support for extended (non-PC) x86 platforms"
296 If you disable this option then the kernel will only support
297 standard PC platforms. (which covers the vast majority of
300 If you enable this option then you'll be able to select support
301 for the following (non-PC) 32 bit x86 platforms:
305 SGI 320/540 (Visual Workstation)
306 Summit/EXA (IBM x440)
307 Unisys ES7000 IA32 series
309 If you have one of these systems, or if you want to build a
310 generic distribution kernel, say Y here - otherwise say N.
314 config X86_EXTENDED_PLATFORM
315 bool "Support for extended (non-PC) x86 platforms"
318 If you disable this option then the kernel will only support
319 standard PC platforms. (which covers the vast majority of
322 If you enable this option then you'll be able to select support
323 for the following (non-PC) 64 bit x86 platforms:
327 If you have one of these systems, or if you want to build a
328 generic distribution kernel, say Y here - otherwise say N.
330 # This is an alphabetically sorted list of 64 bit extended platforms
331 # Please maintain the alphabetic order if and when there are additions
336 depends on X86_64 && PCI
337 depends on X86_EXTENDED_PLATFORM
339 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
340 supposed to run on these EM64T-based machines. Only choose this option
341 if you have one of these machines.
344 bool "SGI Ultraviolet"
346 depends on X86_EXTENDED_PLATFORM
349 This option is needed in order to support SGI Ultraviolet systems.
350 If you don't have one of these, you should say N here.
352 # Following is an alphabetically sorted list of 32 bit extended platforms
353 # Please maintain the alphabetic order if and when there are additions
358 depends on X86_EXTENDED_PLATFORM
360 Select this for an AMD Elan processor.
362 Do not use this option for K6/Athlon/Opteron processors!
364 If unsure, choose "PC-compatible" instead.
367 bool "RDC R-321x SoC"
369 depends on X86_EXTENDED_PLATFORM
371 select X86_REBOOTFIXUPS
373 This option is needed for RDC R-321x system-on-chip, also known
375 If you don't have one of these chips, you should say N here.
377 config X86_32_NON_STANDARD
378 bool "Support non-standard 32-bit SMP architectures"
379 depends on X86_32 && SMP
380 depends on X86_EXTENDED_PLATFORM
382 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
383 subarchitectures. It is intended for a generic binary kernel.
384 if you select them all, kernel will probe it one by one. and will
387 # Alphabetically sorted list of Non standard 32 bit platforms
390 bool "NUMAQ (IBM/Sequent)"
391 depends on X86_32_NON_STANDARD
395 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
396 NUMA multiquad box. This changes the way that processors are
397 bootstrapped, and uses Clustered Logical APIC addressing mode instead
398 of Flat Logical. You will need a new lynxer.elf file to flash your
399 firmware with - send email to <Martin.Bligh@us.ibm.com>.
402 bool "SGI 320/540 (Visual Workstation)"
403 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
404 depends on X86_32_NON_STANDARD
406 The SGI Visual Workstation series is an IA32-based workstation
407 based on SGI systems chips with some legacy PC hardware attached.
409 Say Y here to create a kernel to run on the SGI 320 or 540.
411 A kernel compiled for the Visual Workstation will run on general
412 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
415 bool "Summit/EXA (IBM x440)"
416 depends on X86_32_NON_STANDARD
418 This option is needed for IBM systems that use the Summit/EXA chipset.
419 In particular, it is needed for the x440.
422 bool "Unisys ES7000 IA32 series"
423 depends on X86_32_NON_STANDARD && X86_BIGSMP
425 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
426 supposed to run on an IA32-based Unisys ES7000 system.
428 config SCHED_OMIT_FRAME_POINTER
430 prompt "Single-depth WCHAN output"
433 Calculate simpler /proc/<PID>/wchan values. If this option
434 is disabled then wchan values will recurse back to the
435 caller function. This provides more accurate wchan values,
436 at the expense of slightly more scheduling overhead.
438 If in doubt, say "Y".
440 menuconfig PARAVIRT_GUEST
441 bool "Paravirtualized guest support"
443 Say Y here to get to see options related to running Linux under
444 various hypervisors. This option alone does not add any kernel code.
446 If you say N, all options in this submenu will be skipped and disabled.
450 source "arch/x86/xen/Kconfig"
453 bool "VMI Guest support"
457 VMI provides a paravirtualized interface to the VMware ESX server
458 (it could be used by other hypervisors in theory too, but is not
459 at the moment), by linking the kernel to a GPL-ed ROM module
460 provided by the hypervisor.
463 bool "KVM paravirtualized clock"
465 select PARAVIRT_CLOCK
467 Turning on this option will allow you to run a paravirtualized clock
468 when running over the KVM hypervisor. Instead of relying on a PIT
469 (or probably other) emulation by the underlying device model, the host
470 provides the guest with timing infrastructure such as time of day, and
474 bool "KVM Guest support"
477 This option enables various optimizations for running under the KVM
480 source "arch/x86/lguest/Kconfig"
483 bool "Enable paravirtualization code"
485 This changes the kernel so it can modify itself when it is run
486 under a hypervisor, potentially improving performance significantly
487 over full virtualization. However, when run without a hypervisor
488 the kernel is theoretically slower and slightly larger.
490 config PARAVIRT_CLOCK
496 config PARAVIRT_DEBUG
497 bool "paravirt-ops debugging"
498 depends on PARAVIRT && DEBUG_KERNEL
500 Enable to debug paravirt_ops internals. Specifically, BUG if
501 a paravirt_op is missing when it is called.
506 This option adds a kernel parameter 'memtest', which allows memtest
508 memtest=0, mean disabled; -- default
509 memtest=1, mean do 1 test pattern;
511 memtest=4, mean do 4 test patterns.
512 If you are unsure how to answer this question, answer N.
514 config X86_SUMMIT_NUMA
516 depends on X86_32 && NUMA && X86_32_NON_STANDARD
518 config X86_CYCLONE_TIMER
520 depends on X86_32_NON_STANDARD
522 source "arch/x86/Kconfig.cpu"
526 prompt "HPET Timer Support" if X86_32
528 Use the IA-PC HPET (High Precision Event Timer) to manage
529 time in preference to the PIT and RTC, if a HPET is
531 HPET is the next generation timer replacing legacy 8254s.
532 The HPET provides a stable time base on SMP
533 systems, unlike the TSC, but it is more expensive to access,
534 as it is off-chip. You can find the HPET spec at
535 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
537 You can safely choose Y here. However, HPET will only be
538 activated if the platform and the BIOS support this feature.
539 Otherwise the 8254 will be used for timing services.
541 Choose N to continue using the legacy 8254 timer.
543 config HPET_EMULATE_RTC
545 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
547 # Mark as embedded because too many people got it wrong.
548 # The code disables itself when not needed.
551 bool "Enable DMI scanning" if EMBEDDED
553 Enabled scanning of DMI to identify machine quirks. Say Y
554 here unless you have verified that your setup is not
555 affected by entries in the DMI blacklist. Required by PNP
559 bool "GART IOMMU support" if EMBEDDED
563 depends on X86_64 && PCI
565 Support for full DMA access of devices with 32bit memory access only
566 on systems with more than 3GB. This is usually needed for USB,
567 sound, many IDE/SATA chipsets and some other devices.
568 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
569 based hardware IOMMU and a software bounce buffer based IOMMU used
570 on Intel systems and as fallback.
571 The code is only active when needed (enough memory and limited
572 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
576 bool "IBM Calgary IOMMU support"
578 depends on X86_64 && PCI && EXPERIMENTAL
580 Support for hardware IOMMUs in IBM's xSeries x366 and x460
581 systems. Needed to run systems with more than 3GB of memory
582 properly with 32-bit PCI devices that do not support DAC
583 (Double Address Cycle). Calgary also supports bus level
584 isolation, where all DMAs pass through the IOMMU. This
585 prevents them from going anywhere except their intended
586 destination. This catches hard-to-find kernel bugs and
587 mis-behaving drivers and devices that do not use the DMA-API
588 properly to set up their DMA buffers. The IOMMU can be
589 turned off at boot time with the iommu=off parameter.
590 Normally the kernel will make the right choice by itself.
593 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
595 prompt "Should Calgary be enabled by default?"
596 depends on CALGARY_IOMMU
598 Should Calgary be enabled by default? if you choose 'y', Calgary
599 will be used (if it exists). If you choose 'n', Calgary will not be
600 used even if it exists. If you choose 'n' and would like to use
601 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
605 bool "AMD IOMMU support"
608 depends on X86_64 && PCI && ACPI
610 With this option you can enable support for AMD IOMMU hardware in
611 your system. An IOMMU is a hardware component which provides
612 remapping of DMA memory accesses from devices. With an AMD IOMMU you
613 can isolate the the DMA memory of different devices and protect the
614 system from misbehaving device drivers or hardware.
616 You can find out if your system has an AMD IOMMU if you look into
617 your BIOS for an option to enable it or if you have an IVRS ACPI
620 config AMD_IOMMU_STATS
621 bool "Export AMD IOMMU statistics to debugfs"
625 This option enables code in the AMD IOMMU driver to collect various
626 statistics about whats happening in the driver and exports that
627 information to userspace via debugfs.
630 # need this always selected by IOMMU for the VIA workaround
634 Support for software bounce buffers used on x86-64 systems
635 which don't have a hardware IOMMU (e.g. the current generation
636 of Intel's x86-64 CPUs). Using this PCI devices which can only
637 access 32-bits of memory can be used on systems with more than
638 3 GB of memory. If unsure, say Y.
641 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
644 def_bool (AMD_IOMMU || DMAR)
647 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
648 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
649 select CPUMASK_OFFSTACK
652 Configure maximum number of CPUS and NUMA Nodes for this architecture.
656 int "Maximum number of CPUs" if SMP && !MAXSMP
657 range 2 512 if SMP && !MAXSMP
659 default "4096" if MAXSMP
660 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
663 This allows you to specify the maximum number of CPUs which this
664 kernel will support. The maximum supported value is 512 and the
665 minimum value which makes sense is 2.
667 This is purely to save memory - each supported CPU adds
668 approximately eight kilobytes to the kernel image.
671 bool "SMT (Hyperthreading) scheduler support"
674 SMT scheduler support improves the CPU scheduler's decision making
675 when dealing with Intel Pentium 4 chips with HyperThreading at a
676 cost of slightly increased overhead in some places. If unsure say
681 prompt "Multi-core scheduler support"
684 Multi-core scheduler support improves the CPU scheduler's decision
685 making when dealing with multi-core CPU chips at a cost of slightly
686 increased overhead in some places. If unsure say N here.
688 source "kernel/Kconfig.preempt"
691 bool "Local APIC support on uniprocessors"
692 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
694 A local APIC (Advanced Programmable Interrupt Controller) is an
695 integrated interrupt controller in the CPU. If you have a single-CPU
696 system which has a processor with a local APIC, you can say Y here to
697 enable and use it. If you say Y here even though your machine doesn't
698 have a local APIC, then the kernel will still run with no slowdown at
699 all. The local APIC supports CPU-generated self-interrupts (timer,
700 performance counters), and the NMI watchdog which detects hard
704 bool "IO-APIC support on uniprocessors"
705 depends on X86_UP_APIC
707 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
708 SMP-capable replacement for PC-style interrupt controllers. Most
709 SMP systems and many recent uniprocessor systems have one.
711 If you have a single-CPU system with an IO-APIC, you can say Y here
712 to use it. If you say Y here even though your machine doesn't have
713 an IO-APIC, then the kernel will still run with no slowdown at all.
715 config X86_LOCAL_APIC
717 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
721 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
723 config X86_VISWS_APIC
725 depends on X86_32 && X86_VISWS
727 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
728 bool "Reroute for broken boot IRQs"
730 depends on X86_IO_APIC
732 This option enables a workaround that fixes a source of
733 spurious interrupts. This is recommended when threaded
734 interrupt handling is used on systems where the generation of
735 superfluous "boot interrupts" cannot be disabled.
737 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
738 entry in the chipset's IO-APIC is masked (as, e.g. the RT
739 kernel does during interrupt handling). On chipsets where this
740 boot IRQ generation cannot be disabled, this workaround keeps
741 the original IRQ line masked so that only the equivalent "boot
742 IRQ" is delivered to the CPUs. The workaround also tells the
743 kernel to set up the IRQ handler on the boot IRQ line. In this
744 way only one interrupt is delivered to the kernel. Otherwise
745 the spurious second interrupt may cause the kernel to bring
746 down (vital) interrupt lines.
748 Only affects "broken" chipsets. Interrupt sharing may be
749 increased on these systems.
752 bool "Machine Check Exception"
754 Machine Check Exception support allows the processor to notify the
755 kernel if it detects a problem (e.g. overheating, component failure).
756 The action the kernel takes depends on the severity of the problem,
757 ranging from a warning message on the console, to halting the machine.
758 Your processor must be a Pentium or newer to support this - check the
759 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
760 have a design flaw which leads to false MCE events - hence MCE is
761 disabled on all P5 processors, unless explicitly enabled with "mce"
762 as a boot argument. Similarly, if MCE is built in and creates a
763 problem on some new non-standard machine, you can boot with "nomce"
764 to disable it. MCE support simply ignores non-MCE processors like
765 the 386 and 486, so nearly everyone can say Y here.
769 prompt "Intel MCE features"
770 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
772 Additional support for intel specific MCE features such as
777 prompt "AMD MCE features"
778 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
780 Additional support for AMD specific MCE features such as
781 the DRAM Error Threshold.
783 config X86_MCE_NONFATAL
784 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
785 depends on X86_32 && X86_MCE
787 Enabling this feature starts a timer that triggers every 5 seconds which
788 will look at the machine check registers to see if anything happened.
789 Non-fatal problems automatically get corrected (but still logged).
790 Disable this if you don't want to see these messages.
791 Seeing the messages this option prints out may be indicative of dying
792 or out-of-spec (ie, overclocked) hardware.
793 This option only does something on certain CPUs.
794 (AMD Athlon/Duron and Intel Pentium 4)
796 config X86_MCE_P4THERMAL
797 bool "check for P4 thermal throttling interrupt."
798 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
800 Enabling this feature will cause a message to be printed when the P4
801 enters thermal throttling.
804 bool "Enable VM86 support" if EMBEDDED
808 This option is required by programs like DOSEMU to run 16-bit legacy
809 code on X86 processors. It also may be needed by software like
810 XFree86 to initialize some video cards via BIOS. Disabling this
811 option saves about 6k.
814 tristate "Toshiba Laptop support"
817 This adds a driver to safely access the System Management Mode of
818 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
819 not work on models with a Phoenix BIOS. The System Management Mode
820 is used to set the BIOS and power saving options on Toshiba portables.
822 For information on utilities to make use of this driver see the
823 Toshiba Linux utilities web site at:
824 <http://www.buzzard.org.uk/toshiba/>.
826 Say Y if you intend to run this kernel on a Toshiba portable.
830 tristate "Dell laptop support"
832 This adds a driver to safely access the System Management Mode
833 of the CPU on the Dell Inspiron 8000. The System Management Mode
834 is used to read cpu temperature and cooling fan status and to
835 control the fans on the I8K portables.
837 This driver has been tested only on the Inspiron 8000 but it may
838 also work with other Dell laptops. You can force loading on other
839 models by passing the parameter `force=1' to the module. Use at
842 For information on utilities to make use of this driver see the
843 I8K Linux utilities web site at:
844 <http://people.debian.org/~dz/i8k/>
846 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
849 config X86_REBOOTFIXUPS
850 bool "Enable X86 board specific fixups for reboot"
853 This enables chipset and/or board specific fixups to be done
854 in order to get reboot to work correctly. This is only needed on
855 some combinations of hardware and BIOS. The symptom, for which
856 this config is intended, is when reboot ends with a stalled/hung
859 Currently, the only fixup is for the Geode machines using
860 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
862 Say Y if you want to enable the fixup. Currently, it's safe to
863 enable this option even if you don't need it.
867 tristate "/dev/cpu/microcode - microcode support"
870 If you say Y here, you will be able to update the microcode on
871 certain Intel and AMD processors. The Intel support is for the
872 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
873 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
874 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
875 You will obviously need the actual microcode binary data itself
876 which is not shipped with the Linux kernel.
878 This option selects the general module only, you need to select
879 at least one vendor specific module as well.
881 To compile this driver as a module, choose M here: the
882 module will be called microcode.
884 config MICROCODE_INTEL
885 bool "Intel microcode patch loading support"
890 This options enables microcode patch loading support for Intel
893 For latest news and information on obtaining all the required
894 Intel ingredients for this driver, check:
895 <http://www.urbanmyth.org/microcode/>.
898 bool "AMD microcode patch loading support"
902 If you select this option, microcode patch loading support for AMD
903 processors will be enabled.
905 config MICROCODE_OLD_INTERFACE
910 tristate "/dev/cpu/*/msr - Model-specific register support"
912 This device gives privileged processes access to the x86
913 Model-Specific Registers (MSRs). It is a character device with
914 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
915 MSR accesses are directed to a specific CPU on multi-processor
919 tristate "/dev/cpu/*/cpuid - CPU information support"
921 This device gives processes access to the x86 CPUID instruction to
922 be executed on a specific processor. It is a character device
923 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
927 prompt "High Memory Support"
928 default HIGHMEM4G if !X86_NUMAQ
929 default HIGHMEM64G if X86_NUMAQ
934 depends on !X86_NUMAQ
936 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
937 However, the address space of 32-bit x86 processors is only 4
938 Gigabytes large. That means that, if you have a large amount of
939 physical memory, not all of it can be "permanently mapped" by the
940 kernel. The physical memory that's not permanently mapped is called
943 If you are compiling a kernel which will never run on a machine with
944 more than 1 Gigabyte total physical RAM, answer "off" here (default
945 choice and suitable for most users). This will result in a "3GB/1GB"
946 split: 3GB are mapped so that each process sees a 3GB virtual memory
947 space and the remaining part of the 4GB virtual memory space is used
948 by the kernel to permanently map as much physical memory as
951 If the machine has between 1 and 4 Gigabytes physical RAM, then
954 If more than 4 Gigabytes is used then answer "64GB" here. This
955 selection turns Intel PAE (Physical Address Extension) mode on.
956 PAE implements 3-level paging on IA32 processors. PAE is fully
957 supported by Linux, PAE mode is implemented on all recent Intel
958 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
959 then the kernel will not boot on CPUs that don't support PAE!
961 The actual amount of total physical memory will either be
962 auto detected or can be forced by using a kernel command line option
963 such as "mem=256M". (Try "man bootparam" or see the documentation of
964 your boot loader (lilo or loadlin) about how to pass options to the
965 kernel at boot time.)
967 If unsure, say "off".
971 depends on !X86_NUMAQ
973 Select this if you have a 32-bit processor and between 1 and 4
974 gigabytes of physical RAM.
978 depends on !M386 && !M486
981 Select this if you have a 32-bit processor and more than 4
982 gigabytes of physical RAM.
987 depends on EXPERIMENTAL
988 prompt "Memory split" if EMBEDDED
992 Select the desired split between kernel and user memory.
994 If the address range available to the kernel is less than the
995 physical memory installed, the remaining memory will be available
996 as "high memory". Accessing high memory is a little more costly
997 than low memory, as it needs to be mapped into the kernel first.
998 Note that increasing the kernel address space limits the range
999 available to user programs, making the address space there
1000 tighter. Selecting anything other than the default 3G/1G split
1001 will also likely make your kernel incompatible with binary-only
1004 If you are not absolutely sure what you are doing, leave this
1008 bool "3G/1G user/kernel split"
1009 config VMSPLIT_3G_OPT
1011 bool "3G/1G user/kernel split (for full 1G low memory)"
1013 bool "2G/2G user/kernel split"
1014 config VMSPLIT_2G_OPT
1016 bool "2G/2G user/kernel split (for full 2G low memory)"
1018 bool "1G/3G user/kernel split"
1023 default 0xB0000000 if VMSPLIT_3G_OPT
1024 default 0x80000000 if VMSPLIT_2G
1025 default 0x78000000 if VMSPLIT_2G_OPT
1026 default 0x40000000 if VMSPLIT_1G
1032 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1035 bool "PAE (Physical Address Extension) Support"
1036 depends on X86_32 && !HIGHMEM4G
1038 PAE is required for NX support, and furthermore enables
1039 larger swapspace support for non-overcommit purposes. It
1040 has the cost of more pagetable lookup overhead, and also
1041 consumes more pagetable space per process.
1043 config ARCH_PHYS_ADDR_T_64BIT
1044 def_bool X86_64 || X86_PAE
1046 config DIRECT_GBPAGES
1047 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1051 Allow the kernel linear mapping to use 1GB pages on CPUs that
1052 support it. This can improve the kernel's performance a tiny bit by
1053 reducing TLB pressure. If in doubt, say "Y".
1055 # Common NUMA Features
1057 bool "Numa Memory Allocation and Scheduler Support"
1059 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1060 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1062 Enable NUMA (Non Uniform Memory Access) support.
1064 The kernel will try to allocate memory used by a CPU on the
1065 local memory controller of the CPU and add some more
1066 NUMA awareness to the kernel.
1068 For 64-bit this is recommended if the system is Intel Core i7
1069 (or later), AMD Opteron, or EM64T NUMA.
1071 For 32-bit this is only needed on (rare) 32-bit-only platforms
1072 that support NUMA topologies, such as NUMAQ / Summit, or if you
1073 boot a 32-bit kernel on a 64-bit NUMA platform.
1075 Otherwise, you should say N.
1077 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1078 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1082 prompt "Old style AMD Opteron NUMA detection"
1083 depends on X86_64 && NUMA && PCI
1085 Enable K8 NUMA node topology detection. You should say Y here if
1086 you have a multi processor AMD K8 system. This uses an old
1087 method to read the NUMA configuration directly from the builtin
1088 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1089 instead, which also takes priority if both are compiled in.
1091 config X86_64_ACPI_NUMA
1093 prompt "ACPI NUMA detection"
1094 depends on X86_64 && NUMA && ACPI && PCI
1097 Enable ACPI SRAT based node topology detection.
1099 # Some NUMA nodes have memory ranges that span
1100 # other nodes. Even though a pfn is valid and
1101 # between a node's start and end pfns, it may not
1102 # reside on that node. See memmap_init_zone()
1104 config NODES_SPAN_OTHER_NODES
1106 depends on X86_64_ACPI_NUMA
1109 bool "NUMA emulation"
1110 depends on X86_64 && NUMA
1112 Enable NUMA emulation. A flat machine will be split
1113 into virtual nodes when booted with "numa=fake=N", where N is the
1114 number of nodes. This is only useful for debugging.
1117 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1119 default "9" if MAXSMP
1120 default "6" if X86_64
1121 default "4" if X86_NUMAQ
1123 depends on NEED_MULTIPLE_NODES
1125 Specify the maximum number of NUMA Nodes available on the target
1126 system. Increases memory reserved to accomodate various tables.
1128 config HAVE_ARCH_BOOTMEM_NODE
1130 depends on X86_32 && NUMA
1132 config ARCH_HAVE_MEMORY_PRESENT
1134 depends on X86_32 && DISCONTIGMEM
1136 config NEED_NODE_MEMMAP_SIZE
1138 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1140 config HAVE_ARCH_ALLOC_REMAP
1142 depends on X86_32 && NUMA
1144 config ARCH_FLATMEM_ENABLE
1146 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1148 config ARCH_DISCONTIGMEM_ENABLE
1150 depends on NUMA && X86_32
1152 config ARCH_DISCONTIGMEM_DEFAULT
1154 depends on NUMA && X86_32
1156 config ARCH_SPARSEMEM_DEFAULT
1160 config ARCH_SPARSEMEM_ENABLE
1162 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1163 select SPARSEMEM_STATIC if X86_32
1164 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1166 config ARCH_SELECT_MEMORY_MODEL
1168 depends on ARCH_SPARSEMEM_ENABLE
1170 config ARCH_MEMORY_PROBE
1172 depends on MEMORY_HOTPLUG
1177 bool "Allocate 3rd-level pagetables from highmem"
1178 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1180 The VM uses one page table entry for each page of physical memory.
1181 For systems with a lot of RAM, this can be wasteful of precious
1182 low memory. Setting this option will put user-space page table
1183 entries in high memory.
1185 config X86_CHECK_BIOS_CORRUPTION
1186 bool "Check for low memory corruption"
1188 Periodically check for memory corruption in low memory, which
1189 is suspected to be caused by BIOS. Even when enabled in the
1190 configuration, it is disabled at runtime. Enable it by
1191 setting "memory_corruption_check=1" on the kernel command
1192 line. By default it scans the low 64k of memory every 60
1193 seconds; see the memory_corruption_check_size and
1194 memory_corruption_check_period parameters in
1195 Documentation/kernel-parameters.txt to adjust this.
1197 When enabled with the default parameters, this option has
1198 almost no overhead, as it reserves a relatively small amount
1199 of memory and scans it infrequently. It both detects corruption
1200 and prevents it from affecting the running system.
1202 It is, however, intended as a diagnostic tool; if repeatable
1203 BIOS-originated corruption always affects the same memory,
1204 you can use memmap= to prevent the kernel from using that
1207 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1208 bool "Set the default setting of memory_corruption_check"
1209 depends on X86_CHECK_BIOS_CORRUPTION
1212 Set whether the default state of memory_corruption_check is
1215 config X86_RESERVE_LOW_64K
1216 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1219 Reserve the first 64K of physical RAM on BIOSes that are known
1220 to potentially corrupt that memory range. A numbers of BIOSes are
1221 known to utilize this area during suspend/resume, so it must not
1222 be used by the kernel.
1224 Set this to N if you are absolutely sure that you trust the BIOS
1225 to get all its memory reservations and usages right.
1227 If you have doubts about the BIOS (e.g. suspend/resume does not
1228 work or there's kernel crashes after certain hardware hotplug
1229 events) and it's not AMI or Phoenix, then you might want to enable
1230 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1231 corruption patterns.
1235 config MATH_EMULATION
1237 prompt "Math emulation" if X86_32
1239 Linux can emulate a math coprocessor (used for floating point
1240 operations) if you don't have one. 486DX and Pentium processors have
1241 a math coprocessor built in, 486SX and 386 do not, unless you added
1242 a 487DX or 387, respectively. (The messages during boot time can
1243 give you some hints here ["man dmesg"].) Everyone needs either a
1244 coprocessor or this emulation.
1246 If you don't have a math coprocessor, you need to say Y here; if you
1247 say Y here even though you have a coprocessor, the coprocessor will
1248 be used nevertheless. (This behavior can be changed with the kernel
1249 command line option "no387", which comes handy if your coprocessor
1250 is broken. Try "man bootparam" or see the documentation of your boot
1251 loader (lilo or loadlin) about how to pass options to the kernel at
1252 boot time.) This means that it is a good idea to say Y here if you
1253 intend to use this kernel on different machines.
1255 More information about the internals of the Linux math coprocessor
1256 emulation can be found in <file:arch/x86/math-emu/README>.
1258 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1259 kernel, it won't hurt.
1262 bool "MTRR (Memory Type Range Register) support"
1264 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1265 the Memory Type Range Registers (MTRRs) may be used to control
1266 processor access to memory ranges. This is most useful if you have
1267 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1268 allows bus write transfers to be combined into a larger transfer
1269 before bursting over the PCI/AGP bus. This can increase performance
1270 of image write operations 2.5 times or more. Saying Y here creates a
1271 /proc/mtrr file which may be used to manipulate your processor's
1272 MTRRs. Typically the X server should use this.
1274 This code has a reasonably generic interface so that similar
1275 control registers on other processors can be easily supported
1278 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1279 Registers (ARRs) which provide a similar functionality to MTRRs. For
1280 these, the ARRs are used to emulate the MTRRs.
1281 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1282 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1283 write-combining. All of these processors are supported by this code
1284 and it makes sense to say Y here if you have one of them.
1286 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1287 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1288 can lead to all sorts of problems, so it's good to say Y here.
1290 You can safely say Y even if your machine doesn't have MTRRs, you'll
1291 just add about 9 KB to your kernel.
1293 See <file:Documentation/x86/mtrr.txt> for more information.
1295 config MTRR_SANITIZER
1297 prompt "MTRR cleanup support"
1300 Convert MTRR layout from continuous to discrete, so X drivers can
1301 add writeback entries.
1303 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1304 The largest mtrr entry size for a continous block can be set with
1309 config MTRR_SANITIZER_ENABLE_DEFAULT
1310 int "MTRR cleanup enable value (0-1)"
1313 depends on MTRR_SANITIZER
1315 Enable mtrr cleanup default value
1317 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1318 int "MTRR cleanup spare reg num (0-7)"
1321 depends on MTRR_SANITIZER
1323 mtrr cleanup spare entries default, it can be changed via
1324 mtrr_spare_reg_nr=N on the kernel command line.
1328 prompt "x86 PAT support"
1331 Use PAT attributes to setup page level cache control.
1333 PATs are the modern equivalents of MTRRs and are much more
1334 flexible than MTRRs.
1336 Say N here if you see bootup problems (boot crash, boot hang,
1337 spontaneous reboots) or a non-working video driver.
1342 bool "EFI runtime service support"
1345 This enables the kernel to use EFI runtime services that are
1346 available (such as the EFI variable services).
1348 This option is only useful on systems that have EFI firmware.
1349 In addition, you should use the latest ELILO loader available
1350 at <http://elilo.sourceforge.net> in order to take advantage
1351 of EFI runtime services. However, even with this option, the
1352 resultant kernel should continue to boot on existing non-EFI
1357 prompt "Enable seccomp to safely compute untrusted bytecode"
1359 This kernel feature is useful for number crunching applications
1360 that may need to compute untrusted bytecode during their
1361 execution. By using pipes or other transports made available to
1362 the process as file descriptors supporting the read/write
1363 syscalls, it's possible to isolate those applications in
1364 their own address space using seccomp. Once seccomp is
1365 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1366 and the task is only allowed to execute a few safe syscalls
1367 defined by each seccomp mode.
1369 If unsure, say Y. Only embedded should say N here.
1371 config CC_STACKPROTECTOR_ALL
1374 config CC_STACKPROTECTOR
1375 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1376 select CC_STACKPROTECTOR_ALL
1378 This option turns on the -fstack-protector GCC feature. This
1379 feature puts, at the beginning of functions, a canary value on
1380 the stack just before the return address, and validates
1381 the value just before actually returning. Stack based buffer
1382 overflows (that need to overwrite this return address) now also
1383 overwrite the canary, which gets detected and the attack is then
1384 neutralized via a kernel panic.
1386 This feature requires gcc version 4.2 or above, or a distribution
1387 gcc with the feature backported. Older versions are automatically
1388 detected and for those versions, this configuration option is
1389 ignored. (and a warning is printed during bootup)
1391 source kernel/Kconfig.hz
1394 bool "kexec system call"
1396 kexec is a system call that implements the ability to shutdown your
1397 current kernel, and to start another kernel. It is like a reboot
1398 but it is independent of the system firmware. And like a reboot
1399 you can start any kernel with it, not just Linux.
1401 The name comes from the similarity to the exec system call.
1403 It is an ongoing process to be certain the hardware in a machine
1404 is properly shutdown, so do not be surprised if this code does not
1405 initially work for you. It may help to enable device hotplugging
1406 support. As of this writing the exact hardware interface is
1407 strongly in flux, so no good recommendation can be made.
1410 bool "kernel crash dumps"
1411 depends on X86_64 || (X86_32 && HIGHMEM)
1413 Generate crash dump after being started by kexec.
1414 This should be normally only set in special crash dump kernels
1415 which are loaded in the main kernel with kexec-tools into
1416 a specially reserved region and then later executed after
1417 a crash by kdump/kexec. The crash dump kernel must be compiled
1418 to a memory address not used by the main kernel or BIOS using
1419 PHYSICAL_START, or it must be built as a relocatable image
1420 (CONFIG_RELOCATABLE=y).
1421 For more details see Documentation/kdump/kdump.txt
1424 bool "kexec jump (EXPERIMENTAL)"
1425 depends on EXPERIMENTAL
1426 depends on KEXEC && HIBERNATION && X86_32
1428 Jump between original kernel and kexeced kernel and invoke
1429 code in physical address mode via KEXEC
1431 config PHYSICAL_START
1432 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1433 default "0x1000000" if X86_NUMAQ
1434 default "0x200000" if X86_64
1437 This gives the physical address where the kernel is loaded.
1439 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1440 bzImage will decompress itself to above physical address and
1441 run from there. Otherwise, bzImage will run from the address where
1442 it has been loaded by the boot loader and will ignore above physical
1445 In normal kdump cases one does not have to set/change this option
1446 as now bzImage can be compiled as a completely relocatable image
1447 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1448 address. This option is mainly useful for the folks who don't want
1449 to use a bzImage for capturing the crash dump and want to use a
1450 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1451 to be specifically compiled to run from a specific memory area
1452 (normally a reserved region) and this option comes handy.
1454 So if you are using bzImage for capturing the crash dump, leave
1455 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1456 Otherwise if you plan to use vmlinux for capturing the crash dump
1457 change this value to start of the reserved region (Typically 16MB
1458 0x1000000). In other words, it can be set based on the "X" value as
1459 specified in the "crashkernel=YM@XM" command line boot parameter
1460 passed to the panic-ed kernel. Typically this parameter is set as
1461 crashkernel=64M@16M. Please take a look at
1462 Documentation/kdump/kdump.txt for more details about crash dumps.
1464 Usage of bzImage for capturing the crash dump is recommended as
1465 one does not have to build two kernels. Same kernel can be used
1466 as production kernel and capture kernel. Above option should have
1467 gone away after relocatable bzImage support is introduced. But it
1468 is present because there are users out there who continue to use
1469 vmlinux for dump capture. This option should go away down the
1472 Don't change this unless you know what you are doing.
1475 bool "Build a relocatable kernel (EXPERIMENTAL)"
1476 depends on EXPERIMENTAL
1478 This builds a kernel image that retains relocation information
1479 so it can be loaded someplace besides the default 1MB.
1480 The relocations tend to make the kernel binary about 10% larger,
1481 but are discarded at runtime.
1483 One use is for the kexec on panic case where the recovery kernel
1484 must live at a different physical address than the primary
1487 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1488 it has been loaded at and the compile time physical address
1489 (CONFIG_PHYSICAL_START) is ignored.
1491 config PHYSICAL_ALIGN
1493 prompt "Alignment value to which kernel should be aligned" if X86_32
1494 default "0x100000" if X86_32
1495 default "0x200000" if X86_64
1496 range 0x2000 0x400000
1498 This value puts the alignment restrictions on physical address
1499 where kernel is loaded and run from. Kernel is compiled for an
1500 address which meets above alignment restriction.
1502 If bootloader loads the kernel at a non-aligned address and
1503 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1504 address aligned to above value and run from there.
1506 If bootloader loads the kernel at a non-aligned address and
1507 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1508 load address and decompress itself to the address it has been
1509 compiled for and run from there. The address for which kernel is
1510 compiled already meets above alignment restrictions. Hence the
1511 end result is that kernel runs from a physical address meeting
1512 above alignment restrictions.
1514 Don't change this unless you know what you are doing.
1517 bool "Support for hot-pluggable CPUs"
1518 depends on SMP && HOTPLUG
1520 Say Y here to allow turning CPUs off and on. CPUs can be
1521 controlled through /sys/devices/system/cpu.
1522 ( Note: power management support will enable this option
1523 automatically on SMP systems. )
1524 Say N if you want to disable CPU hotplug.
1528 prompt "Compat VDSO support"
1529 depends on X86_32 || IA32_EMULATION
1531 Map the 32-bit VDSO to the predictable old-style address too.
1533 Say N here if you are running a sufficiently recent glibc
1534 version (2.3.3 or later), to remove the high-mapped
1535 VDSO mapping and to exclusively use the randomized VDSO.
1540 bool "Built-in kernel command line"
1543 Allow for specifying boot arguments to the kernel at
1544 build time. On some systems (e.g. embedded ones), it is
1545 necessary or convenient to provide some or all of the
1546 kernel boot arguments with the kernel itself (that is,
1547 to not rely on the boot loader to provide them.)
1549 To compile command line arguments into the kernel,
1550 set this option to 'Y', then fill in the
1551 the boot arguments in CONFIG_CMDLINE.
1553 Systems with fully functional boot loaders (i.e. non-embedded)
1554 should leave this option set to 'N'.
1557 string "Built-in kernel command string"
1558 depends on CMDLINE_BOOL
1561 Enter arguments here that should be compiled into the kernel
1562 image and used at boot time. If the boot loader provides a
1563 command line at boot time, it is appended to this string to
1564 form the full kernel command line, when the system boots.
1566 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1567 change this behavior.
1569 In most cases, the command line (whether built-in or provided
1570 by the boot loader) should specify the device for the root
1573 config CMDLINE_OVERRIDE
1574 bool "Built-in command line overrides boot loader arguments"
1576 depends on CMDLINE_BOOL
1578 Set this option to 'Y' to have the kernel ignore the boot loader
1579 command line, and use ONLY the built-in command line.
1581 This is used to work around broken boot loaders. This should
1582 be set to 'N' under normal conditions.
1586 config ARCH_ENABLE_MEMORY_HOTPLUG
1588 depends on X86_64 || (X86_32 && HIGHMEM)
1590 config ARCH_ENABLE_MEMORY_HOTREMOVE
1592 depends on MEMORY_HOTPLUG
1594 config HAVE_ARCH_EARLY_PFN_TO_NID
1598 menu "Power management and ACPI options"
1600 config ARCH_HIBERNATION_HEADER
1602 depends on X86_64 && HIBERNATION
1604 source "kernel/power/Kconfig"
1606 source "drivers/acpi/Kconfig"
1611 depends on APM || APM_MODULE
1614 tristate "APM (Advanced Power Management) BIOS support"
1615 depends on X86_32 && PM_SLEEP
1617 APM is a BIOS specification for saving power using several different
1618 techniques. This is mostly useful for battery powered laptops with
1619 APM compliant BIOSes. If you say Y here, the system time will be
1620 reset after a RESUME operation, the /proc/apm device will provide
1621 battery status information, and user-space programs will receive
1622 notification of APM "events" (e.g. battery status change).
1624 If you select "Y" here, you can disable actual use of the APM
1625 BIOS by passing the "apm=off" option to the kernel at boot time.
1627 Note that the APM support is almost completely disabled for
1628 machines with more than one CPU.
1630 In order to use APM, you will need supporting software. For location
1631 and more information, read <file:Documentation/power/pm.txt> and the
1632 Battery Powered Linux mini-HOWTO, available from
1633 <http://www.tldp.org/docs.html#howto>.
1635 This driver does not spin down disk drives (see the hdparm(8)
1636 manpage ("man 8 hdparm") for that), and it doesn't turn off
1637 VESA-compliant "green" monitors.
1639 This driver does not support the TI 4000M TravelMate and the ACER
1640 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1641 desktop machines also don't have compliant BIOSes, and this driver
1642 may cause those machines to panic during the boot phase.
1644 Generally, if you don't have a battery in your machine, there isn't
1645 much point in using this driver and you should say N. If you get
1646 random kernel OOPSes or reboots that don't seem to be related to
1647 anything, try disabling/enabling this option (or disabling/enabling
1650 Some other things you should try when experiencing seemingly random,
1653 1) make sure that you have enough swap space and that it is
1655 2) pass the "no-hlt" option to the kernel
1656 3) switch on floating point emulation in the kernel and pass
1657 the "no387" option to the kernel
1658 4) pass the "floppy=nodma" option to the kernel
1659 5) pass the "mem=4M" option to the kernel (thereby disabling
1660 all but the first 4 MB of RAM)
1661 6) make sure that the CPU is not over clocked.
1662 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1663 8) disable the cache from your BIOS settings
1664 9) install a fan for the video card or exchange video RAM
1665 10) install a better fan for the CPU
1666 11) exchange RAM chips
1667 12) exchange the motherboard.
1669 To compile this driver as a module, choose M here: the
1670 module will be called apm.
1674 config APM_IGNORE_USER_SUSPEND
1675 bool "Ignore USER SUSPEND"
1677 This option will ignore USER SUSPEND requests. On machines with a
1678 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1679 series notebooks, it is necessary to say Y because of a BIOS bug.
1681 config APM_DO_ENABLE
1682 bool "Enable PM at boot time"
1684 Enable APM features at boot time. From page 36 of the APM BIOS
1685 specification: "When disabled, the APM BIOS does not automatically
1686 power manage devices, enter the Standby State, enter the Suspend
1687 State, or take power saving steps in response to CPU Idle calls."
1688 This driver will make CPU Idle calls when Linux is idle (unless this
1689 feature is turned off -- see "Do CPU IDLE calls", below). This
1690 should always save battery power, but more complicated APM features
1691 will be dependent on your BIOS implementation. You may need to turn
1692 this option off if your computer hangs at boot time when using APM
1693 support, or if it beeps continuously instead of suspending. Turn
1694 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1695 T400CDT. This is off by default since most machines do fine without
1699 bool "Make CPU Idle calls when idle"
1701 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1702 On some machines, this can activate improved power savings, such as
1703 a slowed CPU clock rate, when the machine is idle. These idle calls
1704 are made after the idle loop has run for some length of time (e.g.,
1705 333 mS). On some machines, this will cause a hang at boot time or
1706 whenever the CPU becomes idle. (On machines with more than one CPU,
1707 this option does nothing.)
1709 config APM_DISPLAY_BLANK
1710 bool "Enable console blanking using APM"
1712 Enable console blanking using the APM. Some laptops can use this to
1713 turn off the LCD backlight when the screen blanker of the Linux
1714 virtual console blanks the screen. Note that this is only used by
1715 the virtual console screen blanker, and won't turn off the backlight
1716 when using the X Window system. This also doesn't have anything to
1717 do with your VESA-compliant power-saving monitor. Further, this
1718 option doesn't work for all laptops -- it might not turn off your
1719 backlight at all, or it might print a lot of errors to the console,
1720 especially if you are using gpm.
1722 config APM_ALLOW_INTS
1723 bool "Allow interrupts during APM BIOS calls"
1725 Normally we disable external interrupts while we are making calls to
1726 the APM BIOS as a measure to lessen the effects of a badly behaving
1727 BIOS implementation. The BIOS should reenable interrupts if it
1728 needs to. Unfortunately, some BIOSes do not -- especially those in
1729 many of the newer IBM Thinkpads. If you experience hangs when you
1730 suspend, try setting this to Y. Otherwise, say N.
1734 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1736 source "drivers/cpuidle/Kconfig"
1738 source "drivers/idle/Kconfig"
1743 menu "Bus options (PCI etc.)"
1748 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1750 Find out whether you have a PCI motherboard. PCI is the name of a
1751 bus system, i.e. the way the CPU talks to the other stuff inside
1752 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1753 VESA. If you have PCI, say Y, otherwise N.
1756 prompt "PCI access mode"
1757 depends on X86_32 && PCI
1760 On PCI systems, the BIOS can be used to detect the PCI devices and
1761 determine their configuration. However, some old PCI motherboards
1762 have BIOS bugs and may crash if this is done. Also, some embedded
1763 PCI-based systems don't have any BIOS at all. Linux can also try to
1764 detect the PCI hardware directly without using the BIOS.
1766 With this option, you can specify how Linux should detect the
1767 PCI devices. If you choose "BIOS", the BIOS will be used,
1768 if you choose "Direct", the BIOS won't be used, and if you
1769 choose "MMConfig", then PCI Express MMCONFIG will be used.
1770 If you choose "Any", the kernel will try MMCONFIG, then the
1771 direct access method and falls back to the BIOS if that doesn't
1772 work. If unsure, go with the default, which is "Any".
1777 config PCI_GOMMCONFIG
1794 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1796 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1799 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1803 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1807 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1814 bool "Support mmconfig PCI config space access"
1815 depends on X86_64 && PCI && ACPI
1818 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1819 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1821 DMA remapping (DMAR) devices support enables independent address
1822 translations for Direct Memory Access (DMA) from devices.
1823 These DMA remapping devices are reported via ACPI tables
1824 and include PCI device scope covered by these DMA
1827 config DMAR_DEFAULT_ON
1829 prompt "Enable DMA Remapping Devices by default"
1832 Selecting this option will enable a DMAR device at boot time if
1833 one is found. If this option is not selected, DMAR support can
1834 be enabled by passing intel_iommu=on to the kernel. It is
1835 recommended you say N here while the DMAR code remains
1840 prompt "Support for Graphics workaround"
1843 Current Graphics drivers tend to use physical address
1844 for DMA and avoid using DMA APIs. Setting this config
1845 option permits the IOMMU driver to set a unity map for
1846 all the OS-visible memory. Hence the driver can continue
1847 to use physical addresses for DMA.
1849 config DMAR_FLOPPY_WA
1853 Floppy disk drivers are know to bypass DMA API calls
1854 thereby failing to work when IOMMU is enabled. This
1855 workaround will setup a 1:1 mapping for the first
1856 16M to make floppy (an ISA device) work.
1859 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1860 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1863 Supports Interrupt remapping for IO-APIC and MSI devices.
1864 To use x2apic mode in the CPU's which support x2APIC enhancements or
1865 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1867 source "drivers/pci/pcie/Kconfig"
1869 source "drivers/pci/Kconfig"
1871 # x86_64 have no ISA slots, but do have ISA-style DMA.
1880 Find out whether you have ISA slots on your motherboard. ISA is the
1881 name of a bus system, i.e. the way the CPU talks to the other stuff
1882 inside your box. Other bus systems are PCI, EISA, MicroChannel
1883 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1884 newer boards don't support it. If you have ISA, say Y, otherwise N.
1890 The Extended Industry Standard Architecture (EISA) bus was
1891 developed as an open alternative to the IBM MicroChannel bus.
1893 The EISA bus provided some of the features of the IBM MicroChannel
1894 bus while maintaining backward compatibility with cards made for
1895 the older ISA bus. The EISA bus saw limited use between 1988 and
1896 1995 when it was made obsolete by the PCI bus.
1898 Say Y here if you are building a kernel for an EISA-based machine.
1902 source "drivers/eisa/Kconfig"
1907 MicroChannel Architecture is found in some IBM PS/2 machines and
1908 laptops. It is a bus system similar to PCI or ISA. See
1909 <file:Documentation/mca.txt> (and especially the web page given
1910 there) before attempting to build an MCA bus kernel.
1912 source "drivers/mca/Kconfig"
1915 tristate "NatSemi SCx200 support"
1917 This provides basic support for National Semiconductor's
1918 (now AMD's) Geode processors. The driver probes for the
1919 PCI-IDs of several on-chip devices, so its a good dependency
1920 for other scx200_* drivers.
1922 If compiled as a module, the driver is named scx200.
1924 config SCx200HR_TIMER
1925 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1926 depends on SCx200 && GENERIC_TIME
1929 This driver provides a clocksource built upon the on-chip
1930 27MHz high-resolution timer. Its also a workaround for
1931 NSC Geode SC-1100's buggy TSC, which loses time when the
1932 processor goes idle (as is done by the scheduler). The
1933 other workaround is idle=poll boot option.
1935 config GEODE_MFGPT_TIMER
1937 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1938 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1940 This driver provides a clock event source based on the MFGPT
1941 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1942 MFGPTs have a better resolution and max interval than the
1943 generic PIT, and are suitable for use as high-res timers.
1946 bool "One Laptop Per Child support"
1949 Add support for detecting the unique features of the OLPC
1956 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1958 source "drivers/pcmcia/Kconfig"
1960 source "drivers/pci/hotplug/Kconfig"
1965 menu "Executable file formats / Emulations"
1967 source "fs/Kconfig.binfmt"
1969 config IA32_EMULATION
1970 bool "IA32 Emulation"
1972 select COMPAT_BINFMT_ELF
1974 Include code to run 32-bit programs under a 64-bit kernel. You should
1975 likely turn this on, unless you're 100% sure that you don't have any
1976 32-bit programs left.
1979 tristate "IA32 a.out support"
1980 depends on IA32_EMULATION
1982 Support old a.out binaries in the 32bit emulation.
1986 depends on IA32_EMULATION
1988 config COMPAT_FOR_U64_ALIGNMENT
1992 config SYSVIPC_COMPAT
1994 depends on COMPAT && SYSVIPC
1999 config HAVE_ATOMIC_IOMAP
2003 source "net/Kconfig"
2005 source "drivers/Kconfig"
2007 source "drivers/firmware/Kconfig"
2011 source "arch/x86/Kconfig.debug"
2013 source "security/Kconfig"
2015 source "crypto/Kconfig"
2017 source "arch/x86/kvm/Kconfig"
2019 source "lib/Kconfig"
projects / linux-2.6 / blob