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_DYNAMIC_PER_CPU_AREA
144 config HAVE_CPUMASK_OF_CPU_MAP
147 config ARCH_HIBERNATION_POSSIBLE
150 config ARCH_SUSPEND_POSSIBLE
157 config ARCH_POPULATES_NODE_MAP
164 config ARCH_SUPPORTS_OPTIMIZED_INLINING
167 # Use the generic interrupt handling code in kernel/irq/:
168 config GENERIC_HARDIRQS
172 config GENERIC_IRQ_PROBE
176 config GENERIC_PENDING_IRQ
178 depends on GENERIC_HARDIRQS && SMP
181 config USE_GENERIC_SMP_HELPERS
187 depends on X86_32 && SMP
191 depends on X86_64 && SMP
198 config X86_TRAMPOLINE
200 depends on SMP || (64BIT && ACPI_SLEEP)
203 config X86_32_LAZY_GS
205 depends on X86_32 && !CC_STACKPROTECTOR
209 source "init/Kconfig"
210 source "kernel/Kconfig.freezer"
212 menu "Processor type and features"
214 source "kernel/time/Kconfig"
217 bool "Symmetric multi-processing support"
219 This enables support for systems with more than one CPU. If you have
220 a system with only one CPU, like most personal computers, say N. If
221 you have a system with more than one CPU, say Y.
223 If you say N here, the kernel will run on single and multiprocessor
224 machines, but will use only one CPU of a multiprocessor machine. If
225 you say Y here, the kernel will run on many, but not all,
226 singleprocessor machines. On a singleprocessor machine, the kernel
227 will run faster if you say N here.
229 Note that if you say Y here and choose architecture "586" or
230 "Pentium" under "Processor family", the kernel will not work on 486
231 architectures. Similarly, multiprocessor kernels for the "PPro"
232 architecture may not work on all Pentium based boards.
234 People using multiprocessor machines who say Y here should also say
235 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
236 Management" code will be disabled if you say Y here.
238 See also <file:Documentation/i386/IO-APIC.txt>,
239 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
240 <http://www.tldp.org/docs.html#howto>.
242 If you don't know what to do here, say N.
245 bool "Support x2apic"
246 depends on X86_LOCAL_APIC && X86_64
248 This enables x2apic support on CPUs that have this feature.
250 This allows 32-bit apic IDs (so it can support very large systems),
251 and accesses the local apic via MSRs not via mmio.
253 ( On certain CPU models you may need to enable INTR_REMAP too,
254 to get functional x2apic mode. )
256 If you don't know what to do here, say N.
259 bool "Support sparse irq numbering"
260 depends on PCI_MSI || HT_IRQ
262 This enables support for sparse irqs. This is useful for distro
263 kernels that want to define a high CONFIG_NR_CPUS value but still
264 want to have low kernel memory footprint on smaller machines.
266 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
267 out the irq_desc[] array in a more NUMA-friendly way. )
269 If you don't know what to do here, say N.
271 config NUMA_MIGRATE_IRQ_DESC
272 bool "Move irq desc when changing irq smp_affinity"
273 depends on SPARSE_IRQ && NUMA
276 This enables moving irq_desc to cpu/node that irq will use handled.
278 If you don't know what to do here, say N.
281 bool "Enable MPS table" if ACPI
283 depends on X86_LOCAL_APIC
285 For old smp systems that do not have proper acpi support. Newer systems
286 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
289 bool "Support for big SMP systems with more than 8 CPUs"
290 depends on X86_32 && SMP
292 This option is needed for the systems that have more than 8 CPUs
295 config X86_EXTENDED_PLATFORM
296 bool "Support for extended (non-PC) x86 platforms"
299 If you disable this option then the kernel will only support
300 standard PC platforms. (which covers the vast majority of
303 If you enable this option then you'll be able to select support
304 for the following (non-PC) 32 bit x86 platforms:
308 SGI 320/540 (Visual Workstation)
309 Summit/EXA (IBM x440)
310 Unisys ES7000 IA32 series
312 If you have one of these systems, or if you want to build a
313 generic distribution kernel, say Y here - otherwise say N.
317 config X86_EXTENDED_PLATFORM
318 bool "Support for extended (non-PC) x86 platforms"
321 If you disable this option then the kernel will only support
322 standard PC platforms. (which covers the vast majority of
325 If you enable this option then you'll be able to select support
326 for the following (non-PC) 64 bit x86 platforms:
330 If you have one of these systems, or if you want to build a
331 generic distribution kernel, say Y here - otherwise say N.
333 # This is an alphabetically sorted list of 64 bit extended platforms
334 # Please maintain the alphabetic order if and when there are additions
339 depends on X86_64 && PCI
340 depends on X86_EXTENDED_PLATFORM
342 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
343 supposed to run on these EM64T-based machines. Only choose this option
344 if you have one of these machines.
347 bool "SGI Ultraviolet"
349 depends on X86_EXTENDED_PLATFORM
352 This option is needed in order to support SGI Ultraviolet systems.
353 If you don't have one of these, you should say N here.
355 # Following is an alphabetically sorted list of 32 bit extended platforms
356 # Please maintain the alphabetic order if and when there are additions
361 depends on X86_EXTENDED_PLATFORM
363 Select this for an AMD Elan processor.
365 Do not use this option for K6/Athlon/Opteron processors!
367 If unsure, choose "PC-compatible" instead.
370 bool "RDC R-321x SoC"
372 depends on X86_EXTENDED_PLATFORM
374 select X86_REBOOTFIXUPS
376 This option is needed for RDC R-321x system-on-chip, also known
378 If you don't have one of these chips, you should say N here.
380 config X86_32_NON_STANDARD
381 bool "Support non-standard 32-bit SMP architectures"
382 depends on X86_32 && SMP
383 depends on X86_EXTENDED_PLATFORM
385 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
386 subarchitectures. It is intended for a generic binary kernel.
387 if you select them all, kernel will probe it one by one. and will
390 # Alphabetically sorted list of Non standard 32 bit platforms
393 bool "NUMAQ (IBM/Sequent)"
394 depends on X86_32_NON_STANDARD
398 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
399 NUMA multiquad box. This changes the way that processors are
400 bootstrapped, and uses Clustered Logical APIC addressing mode instead
401 of Flat Logical. You will need a new lynxer.elf file to flash your
402 firmware with - send email to <Martin.Bligh@us.ibm.com>.
405 bool "SGI 320/540 (Visual Workstation)"
406 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
407 depends on X86_32_NON_STANDARD
409 The SGI Visual Workstation series is an IA32-based workstation
410 based on SGI systems chips with some legacy PC hardware attached.
412 Say Y here to create a kernel to run on the SGI 320 or 540.
414 A kernel compiled for the Visual Workstation will run on general
415 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
418 bool "Summit/EXA (IBM x440)"
419 depends on X86_32_NON_STANDARD
421 This option is needed for IBM systems that use the Summit/EXA chipset.
422 In particular, it is needed for the x440.
425 bool "Unisys ES7000 IA32 series"
426 depends on X86_32_NON_STANDARD && X86_BIGSMP
428 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
429 supposed to run on an IA32-based Unisys ES7000 system.
431 config SCHED_OMIT_FRAME_POINTER
433 prompt "Single-depth WCHAN output"
436 Calculate simpler /proc/<PID>/wchan values. If this option
437 is disabled then wchan values will recurse back to the
438 caller function. This provides more accurate wchan values,
439 at the expense of slightly more scheduling overhead.
441 If in doubt, say "Y".
443 menuconfig PARAVIRT_GUEST
444 bool "Paravirtualized guest support"
446 Say Y here to get to see options related to running Linux under
447 various hypervisors. This option alone does not add any kernel code.
449 If you say N, all options in this submenu will be skipped and disabled.
453 source "arch/x86/xen/Kconfig"
456 bool "VMI Guest support"
460 VMI provides a paravirtualized interface to the VMware ESX server
461 (it could be used by other hypervisors in theory too, but is not
462 at the moment), by linking the kernel to a GPL-ed ROM module
463 provided by the hypervisor.
466 bool "KVM paravirtualized clock"
468 select PARAVIRT_CLOCK
470 Turning on this option will allow you to run a paravirtualized clock
471 when running over the KVM hypervisor. Instead of relying on a PIT
472 (or probably other) emulation by the underlying device model, the host
473 provides the guest with timing infrastructure such as time of day, and
477 bool "KVM Guest support"
480 This option enables various optimizations for running under the KVM
483 source "arch/x86/lguest/Kconfig"
486 bool "Enable paravirtualization code"
488 This changes the kernel so it can modify itself when it is run
489 under a hypervisor, potentially improving performance significantly
490 over full virtualization. However, when run without a hypervisor
491 the kernel is theoretically slower and slightly larger.
493 config PARAVIRT_CLOCK
499 config PARAVIRT_DEBUG
500 bool "paravirt-ops debugging"
501 depends on PARAVIRT && DEBUG_KERNEL
503 Enable to debug paravirt_ops internals. Specifically, BUG if
504 a paravirt_op is missing when it is called.
509 This option adds a kernel parameter 'memtest', which allows memtest
511 memtest=0, mean disabled; -- default
512 memtest=1, mean do 1 test pattern;
514 memtest=4, mean do 4 test patterns.
515 If you are unsure how to answer this question, answer N.
517 config X86_SUMMIT_NUMA
519 depends on X86_32 && NUMA && X86_32_NON_STANDARD
521 config X86_CYCLONE_TIMER
523 depends on X86_32_NON_STANDARD
525 source "arch/x86/Kconfig.cpu"
529 prompt "HPET Timer Support" if X86_32
531 Use the IA-PC HPET (High Precision Event Timer) to manage
532 time in preference to the PIT and RTC, if a HPET is
534 HPET is the next generation timer replacing legacy 8254s.
535 The HPET provides a stable time base on SMP
536 systems, unlike the TSC, but it is more expensive to access,
537 as it is off-chip. You can find the HPET spec at
538 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
540 You can safely choose Y here. However, HPET will only be
541 activated if the platform and the BIOS support this feature.
542 Otherwise the 8254 will be used for timing services.
544 Choose N to continue using the legacy 8254 timer.
546 config HPET_EMULATE_RTC
548 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
550 # Mark as embedded because too many people got it wrong.
551 # The code disables itself when not needed.
554 bool "Enable DMI scanning" if EMBEDDED
556 Enabled scanning of DMI to identify machine quirks. Say Y
557 here unless you have verified that your setup is not
558 affected by entries in the DMI blacklist. Required by PNP
562 bool "GART IOMMU support" if EMBEDDED
566 depends on X86_64 && PCI
568 Support for full DMA access of devices with 32bit memory access only
569 on systems with more than 3GB. This is usually needed for USB,
570 sound, many IDE/SATA chipsets and some other devices.
571 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
572 based hardware IOMMU and a software bounce buffer based IOMMU used
573 on Intel systems and as fallback.
574 The code is only active when needed (enough memory and limited
575 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
579 bool "IBM Calgary IOMMU support"
581 depends on X86_64 && PCI && EXPERIMENTAL
583 Support for hardware IOMMUs in IBM's xSeries x366 and x460
584 systems. Needed to run systems with more than 3GB of memory
585 properly with 32-bit PCI devices that do not support DAC
586 (Double Address Cycle). Calgary also supports bus level
587 isolation, where all DMAs pass through the IOMMU. This
588 prevents them from going anywhere except their intended
589 destination. This catches hard-to-find kernel bugs and
590 mis-behaving drivers and devices that do not use the DMA-API
591 properly to set up their DMA buffers. The IOMMU can be
592 turned off at boot time with the iommu=off parameter.
593 Normally the kernel will make the right choice by itself.
596 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
598 prompt "Should Calgary be enabled by default?"
599 depends on CALGARY_IOMMU
601 Should Calgary be enabled by default? if you choose 'y', Calgary
602 will be used (if it exists). If you choose 'n', Calgary will not be
603 used even if it exists. If you choose 'n' and would like to use
604 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
608 bool "AMD IOMMU support"
611 depends on X86_64 && PCI && ACPI
613 With this option you can enable support for AMD IOMMU hardware in
614 your system. An IOMMU is a hardware component which provides
615 remapping of DMA memory accesses from devices. With an AMD IOMMU you
616 can isolate the the DMA memory of different devices and protect the
617 system from misbehaving device drivers or hardware.
619 You can find out if your system has an AMD IOMMU if you look into
620 your BIOS for an option to enable it or if you have an IVRS ACPI
623 config AMD_IOMMU_STATS
624 bool "Export AMD IOMMU statistics to debugfs"
628 This option enables code in the AMD IOMMU driver to collect various
629 statistics about whats happening in the driver and exports that
630 information to userspace via debugfs.
633 # need this always selected by IOMMU for the VIA workaround
637 Support for software bounce buffers used on x86-64 systems
638 which don't have a hardware IOMMU (e.g. the current generation
639 of Intel's x86-64 CPUs). Using this PCI devices which can only
640 access 32-bits of memory can be used on systems with more than
641 3 GB of memory. If unsure, say Y.
644 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
647 def_bool (AMD_IOMMU || DMAR)
650 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
651 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
652 select CPUMASK_OFFSTACK
655 Configure maximum number of CPUS and NUMA Nodes for this architecture.
659 int "Maximum number of CPUs" if SMP && !MAXSMP
660 range 2 512 if SMP && !MAXSMP
662 default "4096" if MAXSMP
663 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
666 This allows you to specify the maximum number of CPUs which this
667 kernel will support. The maximum supported value is 512 and the
668 minimum value which makes sense is 2.
670 This is purely to save memory - each supported CPU adds
671 approximately eight kilobytes to the kernel image.
674 bool "SMT (Hyperthreading) scheduler support"
677 SMT scheduler support improves the CPU scheduler's decision making
678 when dealing with Intel Pentium 4 chips with HyperThreading at a
679 cost of slightly increased overhead in some places. If unsure say
684 prompt "Multi-core scheduler support"
687 Multi-core scheduler support improves the CPU scheduler's decision
688 making when dealing with multi-core CPU chips at a cost of slightly
689 increased overhead in some places. If unsure say N here.
691 source "kernel/Kconfig.preempt"
694 bool "Local APIC support on uniprocessors"
695 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
697 A local APIC (Advanced Programmable Interrupt Controller) is an
698 integrated interrupt controller in the CPU. If you have a single-CPU
699 system which has a processor with a local APIC, you can say Y here to
700 enable and use it. If you say Y here even though your machine doesn't
701 have a local APIC, then the kernel will still run with no slowdown at
702 all. The local APIC supports CPU-generated self-interrupts (timer,
703 performance counters), and the NMI watchdog which detects hard
707 bool "IO-APIC support on uniprocessors"
708 depends on X86_UP_APIC
710 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
711 SMP-capable replacement for PC-style interrupt controllers. Most
712 SMP systems and many recent uniprocessor systems have one.
714 If you have a single-CPU system with an IO-APIC, you can say Y here
715 to use it. If you say Y here even though your machine doesn't have
716 an IO-APIC, then the kernel will still run with no slowdown at all.
718 config X86_LOCAL_APIC
720 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
724 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
726 config X86_VISWS_APIC
728 depends on X86_32 && X86_VISWS
730 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
731 bool "Reroute for broken boot IRQs"
733 depends on X86_IO_APIC
735 This option enables a workaround that fixes a source of
736 spurious interrupts. This is recommended when threaded
737 interrupt handling is used on systems where the generation of
738 superfluous "boot interrupts" cannot be disabled.
740 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
741 entry in the chipset's IO-APIC is masked (as, e.g. the RT
742 kernel does during interrupt handling). On chipsets where this
743 boot IRQ generation cannot be disabled, this workaround keeps
744 the original IRQ line masked so that only the equivalent "boot
745 IRQ" is delivered to the CPUs. The workaround also tells the
746 kernel to set up the IRQ handler on the boot IRQ line. In this
747 way only one interrupt is delivered to the kernel. Otherwise
748 the spurious second interrupt may cause the kernel to bring
749 down (vital) interrupt lines.
751 Only affects "broken" chipsets. Interrupt sharing may be
752 increased on these systems.
755 bool "Machine Check Exception"
757 Machine Check Exception support allows the processor to notify the
758 kernel if it detects a problem (e.g. overheating, component failure).
759 The action the kernel takes depends on the severity of the problem,
760 ranging from a warning message on the console, to halting the machine.
761 Your processor must be a Pentium or newer to support this - check the
762 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
763 have a design flaw which leads to false MCE events - hence MCE is
764 disabled on all P5 processors, unless explicitly enabled with "mce"
765 as a boot argument. Similarly, if MCE is built in and creates a
766 problem on some new non-standard machine, you can boot with "nomce"
767 to disable it. MCE support simply ignores non-MCE processors like
768 the 386 and 486, so nearly everyone can say Y here.
772 prompt "Intel MCE features"
773 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
775 Additional support for intel specific MCE features such as
780 prompt "AMD MCE features"
781 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
783 Additional support for AMD specific MCE features such as
784 the DRAM Error Threshold.
786 config X86_MCE_THRESHOLD
787 depends on X86_MCE_AMD || X86_MCE_INTEL
791 config X86_MCE_NONFATAL
792 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
793 depends on X86_32 && X86_MCE
795 Enabling this feature starts a timer that triggers every 5 seconds which
796 will look at the machine check registers to see if anything happened.
797 Non-fatal problems automatically get corrected (but still logged).
798 Disable this if you don't want to see these messages.
799 Seeing the messages this option prints out may be indicative of dying
800 or out-of-spec (ie, overclocked) hardware.
801 This option only does something on certain CPUs.
802 (AMD Athlon/Duron and Intel Pentium 4)
804 config X86_MCE_P4THERMAL
805 bool "check for P4 thermal throttling interrupt."
806 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
808 Enabling this feature will cause a message to be printed when the P4
809 enters thermal throttling.
812 bool "Enable VM86 support" if EMBEDDED
816 This option is required by programs like DOSEMU to run 16-bit legacy
817 code on X86 processors. It also may be needed by software like
818 XFree86 to initialize some video cards via BIOS. Disabling this
819 option saves about 6k.
822 tristate "Toshiba Laptop support"
825 This adds a driver to safely access the System Management Mode of
826 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
827 not work on models with a Phoenix BIOS. The System Management Mode
828 is used to set the BIOS and power saving options on Toshiba portables.
830 For information on utilities to make use of this driver see the
831 Toshiba Linux utilities web site at:
832 <http://www.buzzard.org.uk/toshiba/>.
834 Say Y if you intend to run this kernel on a Toshiba portable.
838 tristate "Dell laptop support"
840 This adds a driver to safely access the System Management Mode
841 of the CPU on the Dell Inspiron 8000. The System Management Mode
842 is used to read cpu temperature and cooling fan status and to
843 control the fans on the I8K portables.
845 This driver has been tested only on the Inspiron 8000 but it may
846 also work with other Dell laptops. You can force loading on other
847 models by passing the parameter `force=1' to the module. Use at
850 For information on utilities to make use of this driver see the
851 I8K Linux utilities web site at:
852 <http://people.debian.org/~dz/i8k/>
854 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
857 config X86_REBOOTFIXUPS
858 bool "Enable X86 board specific fixups for reboot"
861 This enables chipset and/or board specific fixups to be done
862 in order to get reboot to work correctly. This is only needed on
863 some combinations of hardware and BIOS. The symptom, for which
864 this config is intended, is when reboot ends with a stalled/hung
867 Currently, the only fixup is for the Geode machines using
868 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
870 Say Y if you want to enable the fixup. Currently, it's safe to
871 enable this option even if you don't need it.
875 tristate "/dev/cpu/microcode - microcode support"
878 If you say Y here, you will be able to update the microcode on
879 certain Intel and AMD processors. The Intel support is for the
880 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
881 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
882 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
883 You will obviously need the actual microcode binary data itself
884 which is not shipped with the Linux kernel.
886 This option selects the general module only, you need to select
887 at least one vendor specific module as well.
889 To compile this driver as a module, choose M here: the
890 module will be called microcode.
892 config MICROCODE_INTEL
893 bool "Intel microcode patch loading support"
898 This options enables microcode patch loading support for Intel
901 For latest news and information on obtaining all the required
902 Intel ingredients for this driver, check:
903 <http://www.urbanmyth.org/microcode/>.
906 bool "AMD microcode patch loading support"
910 If you select this option, microcode patch loading support for AMD
911 processors will be enabled.
913 config MICROCODE_OLD_INTERFACE
918 tristate "/dev/cpu/*/msr - Model-specific register support"
920 This device gives privileged processes access to the x86
921 Model-Specific Registers (MSRs). It is a character device with
922 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
923 MSR accesses are directed to a specific CPU on multi-processor
927 tristate "/dev/cpu/*/cpuid - CPU information support"
929 This device gives processes access to the x86 CPUID instruction to
930 be executed on a specific processor. It is a character device
931 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
935 prompt "High Memory Support"
936 default HIGHMEM4G if !X86_NUMAQ
937 default HIGHMEM64G if X86_NUMAQ
942 depends on !X86_NUMAQ
944 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
945 However, the address space of 32-bit x86 processors is only 4
946 Gigabytes large. That means that, if you have a large amount of
947 physical memory, not all of it can be "permanently mapped" by the
948 kernel. The physical memory that's not permanently mapped is called
951 If you are compiling a kernel which will never run on a machine with
952 more than 1 Gigabyte total physical RAM, answer "off" here (default
953 choice and suitable for most users). This will result in a "3GB/1GB"
954 split: 3GB are mapped so that each process sees a 3GB virtual memory
955 space and the remaining part of the 4GB virtual memory space is used
956 by the kernel to permanently map as much physical memory as
959 If the machine has between 1 and 4 Gigabytes physical RAM, then
962 If more than 4 Gigabytes is used then answer "64GB" here. This
963 selection turns Intel PAE (Physical Address Extension) mode on.
964 PAE implements 3-level paging on IA32 processors. PAE is fully
965 supported by Linux, PAE mode is implemented on all recent Intel
966 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
967 then the kernel will not boot on CPUs that don't support PAE!
969 The actual amount of total physical memory will either be
970 auto detected or can be forced by using a kernel command line option
971 such as "mem=256M". (Try "man bootparam" or see the documentation of
972 your boot loader (lilo or loadlin) about how to pass options to the
973 kernel at boot time.)
975 If unsure, say "off".
979 depends on !X86_NUMAQ
981 Select this if you have a 32-bit processor and between 1 and 4
982 gigabytes of physical RAM.
986 depends on !M386 && !M486
989 Select this if you have a 32-bit processor and more than 4
990 gigabytes of physical RAM.
995 depends on EXPERIMENTAL
996 prompt "Memory split" if EMBEDDED
1000 Select the desired split between kernel and user memory.
1002 If the address range available to the kernel is less than the
1003 physical memory installed, the remaining memory will be available
1004 as "high memory". Accessing high memory is a little more costly
1005 than low memory, as it needs to be mapped into the kernel first.
1006 Note that increasing the kernel address space limits the range
1007 available to user programs, making the address space there
1008 tighter. Selecting anything other than the default 3G/1G split
1009 will also likely make your kernel incompatible with binary-only
1012 If you are not absolutely sure what you are doing, leave this
1016 bool "3G/1G user/kernel split"
1017 config VMSPLIT_3G_OPT
1019 bool "3G/1G user/kernel split (for full 1G low memory)"
1021 bool "2G/2G user/kernel split"
1022 config VMSPLIT_2G_OPT
1024 bool "2G/2G user/kernel split (for full 2G low memory)"
1026 bool "1G/3G user/kernel split"
1031 default 0xB0000000 if VMSPLIT_3G_OPT
1032 default 0x80000000 if VMSPLIT_2G
1033 default 0x78000000 if VMSPLIT_2G_OPT
1034 default 0x40000000 if VMSPLIT_1G
1040 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1043 bool "PAE (Physical Address Extension) Support"
1044 depends on X86_32 && !HIGHMEM4G
1046 PAE is required for NX support, and furthermore enables
1047 larger swapspace support for non-overcommit purposes. It
1048 has the cost of more pagetable lookup overhead, and also
1049 consumes more pagetable space per process.
1051 config ARCH_PHYS_ADDR_T_64BIT
1052 def_bool X86_64 || X86_PAE
1054 config DIRECT_GBPAGES
1055 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1059 Allow the kernel linear mapping to use 1GB pages on CPUs that
1060 support it. This can improve the kernel's performance a tiny bit by
1061 reducing TLB pressure. If in doubt, say "Y".
1063 # Common NUMA Features
1065 bool "Numa Memory Allocation and Scheduler Support"
1067 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1068 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1070 Enable NUMA (Non Uniform Memory Access) support.
1072 The kernel will try to allocate memory used by a CPU on the
1073 local memory controller of the CPU and add some more
1074 NUMA awareness to the kernel.
1076 For 64-bit this is recommended if the system is Intel Core i7
1077 (or later), AMD Opteron, or EM64T NUMA.
1079 For 32-bit this is only needed on (rare) 32-bit-only platforms
1080 that support NUMA topologies, such as NUMAQ / Summit, or if you
1081 boot a 32-bit kernel on a 64-bit NUMA platform.
1083 Otherwise, you should say N.
1085 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1086 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1090 prompt "Old style AMD Opteron NUMA detection"
1091 depends on X86_64 && NUMA && PCI
1093 Enable K8 NUMA node topology detection. You should say Y here if
1094 you have a multi processor AMD K8 system. This uses an old
1095 method to read the NUMA configuration directly from the builtin
1096 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1097 instead, which also takes priority if both are compiled in.
1099 config X86_64_ACPI_NUMA
1101 prompt "ACPI NUMA detection"
1102 depends on X86_64 && NUMA && ACPI && PCI
1105 Enable ACPI SRAT based node topology detection.
1107 # Some NUMA nodes have memory ranges that span
1108 # other nodes. Even though a pfn is valid and
1109 # between a node's start and end pfns, it may not
1110 # reside on that node. See memmap_init_zone()
1112 config NODES_SPAN_OTHER_NODES
1114 depends on X86_64_ACPI_NUMA
1117 bool "NUMA emulation"
1118 depends on X86_64 && NUMA
1120 Enable NUMA emulation. A flat machine will be split
1121 into virtual nodes when booted with "numa=fake=N", where N is the
1122 number of nodes. This is only useful for debugging.
1125 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1127 default "9" if MAXSMP
1128 default "6" if X86_64
1129 default "4" if X86_NUMAQ
1131 depends on NEED_MULTIPLE_NODES
1133 Specify the maximum number of NUMA Nodes available on the target
1134 system. Increases memory reserved to accomodate various tables.
1136 config HAVE_ARCH_BOOTMEM
1138 depends on X86_32 && NUMA
1140 config ARCH_HAVE_MEMORY_PRESENT
1142 depends on X86_32 && DISCONTIGMEM
1144 config NEED_NODE_MEMMAP_SIZE
1146 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1148 config HAVE_ARCH_ALLOC_REMAP
1150 depends on X86_32 && NUMA
1152 config ARCH_FLATMEM_ENABLE
1154 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1156 config ARCH_DISCONTIGMEM_ENABLE
1158 depends on NUMA && X86_32
1160 config ARCH_DISCONTIGMEM_DEFAULT
1162 depends on NUMA && X86_32
1164 config ARCH_SPARSEMEM_DEFAULT
1168 config ARCH_SPARSEMEM_ENABLE
1170 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1171 select SPARSEMEM_STATIC if X86_32
1172 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1174 config ARCH_SELECT_MEMORY_MODEL
1176 depends on ARCH_SPARSEMEM_ENABLE
1178 config ARCH_MEMORY_PROBE
1180 depends on MEMORY_HOTPLUG
1185 bool "Allocate 3rd-level pagetables from highmem"
1186 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1188 The VM uses one page table entry for each page of physical memory.
1189 For systems with a lot of RAM, this can be wasteful of precious
1190 low memory. Setting this option will put user-space page table
1191 entries in high memory.
1193 config X86_CHECK_BIOS_CORRUPTION
1194 bool "Check for low memory corruption"
1196 Periodically check for memory corruption in low memory, which
1197 is suspected to be caused by BIOS. Even when enabled in the
1198 configuration, it is disabled at runtime. Enable it by
1199 setting "memory_corruption_check=1" on the kernel command
1200 line. By default it scans the low 64k of memory every 60
1201 seconds; see the memory_corruption_check_size and
1202 memory_corruption_check_period parameters in
1203 Documentation/kernel-parameters.txt to adjust this.
1205 When enabled with the default parameters, this option has
1206 almost no overhead, as it reserves a relatively small amount
1207 of memory and scans it infrequently. It both detects corruption
1208 and prevents it from affecting the running system.
1210 It is, however, intended as a diagnostic tool; if repeatable
1211 BIOS-originated corruption always affects the same memory,
1212 you can use memmap= to prevent the kernel from using that
1215 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1216 bool "Set the default setting of memory_corruption_check"
1217 depends on X86_CHECK_BIOS_CORRUPTION
1220 Set whether the default state of memory_corruption_check is
1223 config X86_RESERVE_LOW_64K
1224 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1227 Reserve the first 64K of physical RAM on BIOSes that are known
1228 to potentially corrupt that memory range. A numbers of BIOSes are
1229 known to utilize this area during suspend/resume, so it must not
1230 be used by the kernel.
1232 Set this to N if you are absolutely sure that you trust the BIOS
1233 to get all its memory reservations and usages right.
1235 If you have doubts about the BIOS (e.g. suspend/resume does not
1236 work or there's kernel crashes after certain hardware hotplug
1237 events) and it's not AMI or Phoenix, then you might want to enable
1238 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1239 corruption patterns.
1243 config MATH_EMULATION
1245 prompt "Math emulation" if X86_32
1247 Linux can emulate a math coprocessor (used for floating point
1248 operations) if you don't have one. 486DX and Pentium processors have
1249 a math coprocessor built in, 486SX and 386 do not, unless you added
1250 a 487DX or 387, respectively. (The messages during boot time can
1251 give you some hints here ["man dmesg"].) Everyone needs either a
1252 coprocessor or this emulation.
1254 If you don't have a math coprocessor, you need to say Y here; if you
1255 say Y here even though you have a coprocessor, the coprocessor will
1256 be used nevertheless. (This behavior can be changed with the kernel
1257 command line option "no387", which comes handy if your coprocessor
1258 is broken. Try "man bootparam" or see the documentation of your boot
1259 loader (lilo or loadlin) about how to pass options to the kernel at
1260 boot time.) This means that it is a good idea to say Y here if you
1261 intend to use this kernel on different machines.
1263 More information about the internals of the Linux math coprocessor
1264 emulation can be found in <file:arch/x86/math-emu/README>.
1266 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1267 kernel, it won't hurt.
1270 bool "MTRR (Memory Type Range Register) support"
1272 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1273 the Memory Type Range Registers (MTRRs) may be used to control
1274 processor access to memory ranges. This is most useful if you have
1275 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1276 allows bus write transfers to be combined into a larger transfer
1277 before bursting over the PCI/AGP bus. This can increase performance
1278 of image write operations 2.5 times or more. Saying Y here creates a
1279 /proc/mtrr file which may be used to manipulate your processor's
1280 MTRRs. Typically the X server should use this.
1282 This code has a reasonably generic interface so that similar
1283 control registers on other processors can be easily supported
1286 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1287 Registers (ARRs) which provide a similar functionality to MTRRs. For
1288 these, the ARRs are used to emulate the MTRRs.
1289 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1290 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1291 write-combining. All of these processors are supported by this code
1292 and it makes sense to say Y here if you have one of them.
1294 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1295 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1296 can lead to all sorts of problems, so it's good to say Y here.
1298 You can safely say Y even if your machine doesn't have MTRRs, you'll
1299 just add about 9 KB to your kernel.
1301 See <file:Documentation/x86/mtrr.txt> for more information.
1303 config MTRR_SANITIZER
1305 prompt "MTRR cleanup support"
1308 Convert MTRR layout from continuous to discrete, so X drivers can
1309 add writeback entries.
1311 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1312 The largest mtrr entry size for a continous block can be set with
1317 config MTRR_SANITIZER_ENABLE_DEFAULT
1318 int "MTRR cleanup enable value (0-1)"
1321 depends on MTRR_SANITIZER
1323 Enable mtrr cleanup default value
1325 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1326 int "MTRR cleanup spare reg num (0-7)"
1329 depends on MTRR_SANITIZER
1331 mtrr cleanup spare entries default, it can be changed via
1332 mtrr_spare_reg_nr=N on the kernel command line.
1336 prompt "x86 PAT support"
1339 Use PAT attributes to setup page level cache control.
1341 PATs are the modern equivalents of MTRRs and are much more
1342 flexible than MTRRs.
1344 Say N here if you see bootup problems (boot crash, boot hang,
1345 spontaneous reboots) or a non-working video driver.
1350 bool "EFI runtime service support"
1353 This enables the kernel to use EFI runtime services that are
1354 available (such as the EFI variable services).
1356 This option is only useful on systems that have EFI firmware.
1357 In addition, you should use the latest ELILO loader available
1358 at <http://elilo.sourceforge.net> in order to take advantage
1359 of EFI runtime services. However, even with this option, the
1360 resultant kernel should continue to boot on existing non-EFI
1365 prompt "Enable seccomp to safely compute untrusted bytecode"
1367 This kernel feature is useful for number crunching applications
1368 that may need to compute untrusted bytecode during their
1369 execution. By using pipes or other transports made available to
1370 the process as file descriptors supporting the read/write
1371 syscalls, it's possible to isolate those applications in
1372 their own address space using seccomp. Once seccomp is
1373 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1374 and the task is only allowed to execute a few safe syscalls
1375 defined by each seccomp mode.
1377 If unsure, say Y. Only embedded should say N here.
1379 config CC_STACKPROTECTOR_ALL
1382 config CC_STACKPROTECTOR
1383 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1384 select CC_STACKPROTECTOR_ALL
1386 This option turns on the -fstack-protector GCC feature. This
1387 feature puts, at the beginning of functions, a canary value on
1388 the stack just before the return address, and validates
1389 the value just before actually returning. Stack based buffer
1390 overflows (that need to overwrite this return address) now also
1391 overwrite the canary, which gets detected and the attack is then
1392 neutralized via a kernel panic.
1394 This feature requires gcc version 4.2 or above, or a distribution
1395 gcc with the feature backported. Older versions are automatically
1396 detected and for those versions, this configuration option is
1397 ignored. (and a warning is printed during bootup)
1399 source kernel/Kconfig.hz
1402 bool "kexec system call"
1404 kexec is a system call that implements the ability to shutdown your
1405 current kernel, and to start another kernel. It is like a reboot
1406 but it is independent of the system firmware. And like a reboot
1407 you can start any kernel with it, not just Linux.
1409 The name comes from the similarity to the exec system call.
1411 It is an ongoing process to be certain the hardware in a machine
1412 is properly shutdown, so do not be surprised if this code does not
1413 initially work for you. It may help to enable device hotplugging
1414 support. As of this writing the exact hardware interface is
1415 strongly in flux, so no good recommendation can be made.
1418 bool "kernel crash dumps"
1419 depends on X86_64 || (X86_32 && HIGHMEM)
1421 Generate crash dump after being started by kexec.
1422 This should be normally only set in special crash dump kernels
1423 which are loaded in the main kernel with kexec-tools into
1424 a specially reserved region and then later executed after
1425 a crash by kdump/kexec. The crash dump kernel must be compiled
1426 to a memory address not used by the main kernel or BIOS using
1427 PHYSICAL_START, or it must be built as a relocatable image
1428 (CONFIG_RELOCATABLE=y).
1429 For more details see Documentation/kdump/kdump.txt
1432 bool "kexec jump (EXPERIMENTAL)"
1433 depends on EXPERIMENTAL
1434 depends on KEXEC && HIBERNATION && X86_32
1436 Jump between original kernel and kexeced kernel and invoke
1437 code in physical address mode via KEXEC
1439 config PHYSICAL_START
1440 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1441 default "0x1000000" if X86_NUMAQ
1442 default "0x200000" if X86_64
1445 This gives the physical address where the kernel is loaded.
1447 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1448 bzImage will decompress itself to above physical address and
1449 run from there. Otherwise, bzImage will run from the address where
1450 it has been loaded by the boot loader and will ignore above physical
1453 In normal kdump cases one does not have to set/change this option
1454 as now bzImage can be compiled as a completely relocatable image
1455 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1456 address. This option is mainly useful for the folks who don't want
1457 to use a bzImage for capturing the crash dump and want to use a
1458 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1459 to be specifically compiled to run from a specific memory area
1460 (normally a reserved region) and this option comes handy.
1462 So if you are using bzImage for capturing the crash dump, leave
1463 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1464 Otherwise if you plan to use vmlinux for capturing the crash dump
1465 change this value to start of the reserved region (Typically 16MB
1466 0x1000000). In other words, it can be set based on the "X" value as
1467 specified in the "crashkernel=YM@XM" command line boot parameter
1468 passed to the panic-ed kernel. Typically this parameter is set as
1469 crashkernel=64M@16M. Please take a look at
1470 Documentation/kdump/kdump.txt for more details about crash dumps.
1472 Usage of bzImage for capturing the crash dump is recommended as
1473 one does not have to build two kernels. Same kernel can be used
1474 as production kernel and capture kernel. Above option should have
1475 gone away after relocatable bzImage support is introduced. But it
1476 is present because there are users out there who continue to use
1477 vmlinux for dump capture. This option should go away down the
1480 Don't change this unless you know what you are doing.
1483 bool "Build a relocatable kernel (EXPERIMENTAL)"
1484 depends on EXPERIMENTAL
1486 This builds a kernel image that retains relocation information
1487 so it can be loaded someplace besides the default 1MB.
1488 The relocations tend to make the kernel binary about 10% larger,
1489 but are discarded at runtime.
1491 One use is for the kexec on panic case where the recovery kernel
1492 must live at a different physical address than the primary
1495 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1496 it has been loaded at and the compile time physical address
1497 (CONFIG_PHYSICAL_START) is ignored.
1499 config PHYSICAL_ALIGN
1501 prompt "Alignment value to which kernel should be aligned" if X86_32
1502 default "0x100000" if X86_32
1503 default "0x200000" if X86_64
1504 range 0x2000 0x400000
1506 This value puts the alignment restrictions on physical address
1507 where kernel is loaded and run from. Kernel is compiled for an
1508 address which meets above alignment restriction.
1510 If bootloader loads the kernel at a non-aligned address and
1511 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1512 address aligned to above value and run from there.
1514 If bootloader loads the kernel at a non-aligned address and
1515 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1516 load address and decompress itself to the address it has been
1517 compiled for and run from there. The address for which kernel is
1518 compiled already meets above alignment restrictions. Hence the
1519 end result is that kernel runs from a physical address meeting
1520 above alignment restrictions.
1522 Don't change this unless you know what you are doing.
1525 bool "Support for hot-pluggable CPUs"
1526 depends on SMP && HOTPLUG
1528 Say Y here to allow turning CPUs off and on. CPUs can be
1529 controlled through /sys/devices/system/cpu.
1530 ( Note: power management support will enable this option
1531 automatically on SMP systems. )
1532 Say N if you want to disable CPU hotplug.
1536 prompt "Compat VDSO support"
1537 depends on X86_32 || IA32_EMULATION
1539 Map the 32-bit VDSO to the predictable old-style address too.
1541 Say N here if you are running a sufficiently recent glibc
1542 version (2.3.3 or later), to remove the high-mapped
1543 VDSO mapping and to exclusively use the randomized VDSO.
1548 bool "Built-in kernel command line"
1551 Allow for specifying boot arguments to the kernel at
1552 build time. On some systems (e.g. embedded ones), it is
1553 necessary or convenient to provide some or all of the
1554 kernel boot arguments with the kernel itself (that is,
1555 to not rely on the boot loader to provide them.)
1557 To compile command line arguments into the kernel,
1558 set this option to 'Y', then fill in the
1559 the boot arguments in CONFIG_CMDLINE.
1561 Systems with fully functional boot loaders (i.e. non-embedded)
1562 should leave this option set to 'N'.
1565 string "Built-in kernel command string"
1566 depends on CMDLINE_BOOL
1569 Enter arguments here that should be compiled into the kernel
1570 image and used at boot time. If the boot loader provides a
1571 command line at boot time, it is appended to this string to
1572 form the full kernel command line, when the system boots.
1574 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1575 change this behavior.
1577 In most cases, the command line (whether built-in or provided
1578 by the boot loader) should specify the device for the root
1581 config CMDLINE_OVERRIDE
1582 bool "Built-in command line overrides boot loader arguments"
1584 depends on CMDLINE_BOOL
1586 Set this option to 'Y' to have the kernel ignore the boot loader
1587 command line, and use ONLY the built-in command line.
1589 This is used to work around broken boot loaders. This should
1590 be set to 'N' under normal conditions.
1594 config ARCH_ENABLE_MEMORY_HOTPLUG
1596 depends on X86_64 || (X86_32 && HIGHMEM)
1598 config ARCH_ENABLE_MEMORY_HOTREMOVE
1600 depends on MEMORY_HOTPLUG
1602 config HAVE_ARCH_EARLY_PFN_TO_NID
1606 menu "Power management and ACPI options"
1608 config ARCH_HIBERNATION_HEADER
1610 depends on X86_64 && HIBERNATION
1612 source "kernel/power/Kconfig"
1614 source "drivers/acpi/Kconfig"
1619 depends on APM || APM_MODULE
1622 tristate "APM (Advanced Power Management) BIOS support"
1623 depends on X86_32 && PM_SLEEP
1625 APM is a BIOS specification for saving power using several different
1626 techniques. This is mostly useful for battery powered laptops with
1627 APM compliant BIOSes. If you say Y here, the system time will be
1628 reset after a RESUME operation, the /proc/apm device will provide
1629 battery status information, and user-space programs will receive
1630 notification of APM "events" (e.g. battery status change).
1632 If you select "Y" here, you can disable actual use of the APM
1633 BIOS by passing the "apm=off" option to the kernel at boot time.
1635 Note that the APM support is almost completely disabled for
1636 machines with more than one CPU.
1638 In order to use APM, you will need supporting software. For location
1639 and more information, read <file:Documentation/power/pm.txt> and the
1640 Battery Powered Linux mini-HOWTO, available from
1641 <http://www.tldp.org/docs.html#howto>.
1643 This driver does not spin down disk drives (see the hdparm(8)
1644 manpage ("man 8 hdparm") for that), and it doesn't turn off
1645 VESA-compliant "green" monitors.
1647 This driver does not support the TI 4000M TravelMate and the ACER
1648 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1649 desktop machines also don't have compliant BIOSes, and this driver
1650 may cause those machines to panic during the boot phase.
1652 Generally, if you don't have a battery in your machine, there isn't
1653 much point in using this driver and you should say N. If you get
1654 random kernel OOPSes or reboots that don't seem to be related to
1655 anything, try disabling/enabling this option (or disabling/enabling
1658 Some other things you should try when experiencing seemingly random,
1661 1) make sure that you have enough swap space and that it is
1663 2) pass the "no-hlt" option to the kernel
1664 3) switch on floating point emulation in the kernel and pass
1665 the "no387" option to the kernel
1666 4) pass the "floppy=nodma" option to the kernel
1667 5) pass the "mem=4M" option to the kernel (thereby disabling
1668 all but the first 4 MB of RAM)
1669 6) make sure that the CPU is not over clocked.
1670 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1671 8) disable the cache from your BIOS settings
1672 9) install a fan for the video card or exchange video RAM
1673 10) install a better fan for the CPU
1674 11) exchange RAM chips
1675 12) exchange the motherboard.
1677 To compile this driver as a module, choose M here: the
1678 module will be called apm.
1682 config APM_IGNORE_USER_SUSPEND
1683 bool "Ignore USER SUSPEND"
1685 This option will ignore USER SUSPEND requests. On machines with a
1686 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1687 series notebooks, it is necessary to say Y because of a BIOS bug.
1689 config APM_DO_ENABLE
1690 bool "Enable PM at boot time"
1692 Enable APM features at boot time. From page 36 of the APM BIOS
1693 specification: "When disabled, the APM BIOS does not automatically
1694 power manage devices, enter the Standby State, enter the Suspend
1695 State, or take power saving steps in response to CPU Idle calls."
1696 This driver will make CPU Idle calls when Linux is idle (unless this
1697 feature is turned off -- see "Do CPU IDLE calls", below). This
1698 should always save battery power, but more complicated APM features
1699 will be dependent on your BIOS implementation. You may need to turn
1700 this option off if your computer hangs at boot time when using APM
1701 support, or if it beeps continuously instead of suspending. Turn
1702 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1703 T400CDT. This is off by default since most machines do fine without
1707 bool "Make CPU Idle calls when idle"
1709 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1710 On some machines, this can activate improved power savings, such as
1711 a slowed CPU clock rate, when the machine is idle. These idle calls
1712 are made after the idle loop has run for some length of time (e.g.,
1713 333 mS). On some machines, this will cause a hang at boot time or
1714 whenever the CPU becomes idle. (On machines with more than one CPU,
1715 this option does nothing.)
1717 config APM_DISPLAY_BLANK
1718 bool "Enable console blanking using APM"
1720 Enable console blanking using the APM. Some laptops can use this to
1721 turn off the LCD backlight when the screen blanker of the Linux
1722 virtual console blanks the screen. Note that this is only used by
1723 the virtual console screen blanker, and won't turn off the backlight
1724 when using the X Window system. This also doesn't have anything to
1725 do with your VESA-compliant power-saving monitor. Further, this
1726 option doesn't work for all laptops -- it might not turn off your
1727 backlight at all, or it might print a lot of errors to the console,
1728 especially if you are using gpm.
1730 config APM_ALLOW_INTS
1731 bool "Allow interrupts during APM BIOS calls"
1733 Normally we disable external interrupts while we are making calls to
1734 the APM BIOS as a measure to lessen the effects of a badly behaving
1735 BIOS implementation. The BIOS should reenable interrupts if it
1736 needs to. Unfortunately, some BIOSes do not -- especially those in
1737 many of the newer IBM Thinkpads. If you experience hangs when you
1738 suspend, try setting this to Y. Otherwise, say N.
1742 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1744 source "drivers/cpuidle/Kconfig"
1746 source "drivers/idle/Kconfig"
1751 menu "Bus options (PCI etc.)"
1756 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1758 Find out whether you have a PCI motherboard. PCI is the name of a
1759 bus system, i.e. the way the CPU talks to the other stuff inside
1760 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1761 VESA. If you have PCI, say Y, otherwise N.
1764 prompt "PCI access mode"
1765 depends on X86_32 && PCI
1768 On PCI systems, the BIOS can be used to detect the PCI devices and
1769 determine their configuration. However, some old PCI motherboards
1770 have BIOS bugs and may crash if this is done. Also, some embedded
1771 PCI-based systems don't have any BIOS at all. Linux can also try to
1772 detect the PCI hardware directly without using the BIOS.
1774 With this option, you can specify how Linux should detect the
1775 PCI devices. If you choose "BIOS", the BIOS will be used,
1776 if you choose "Direct", the BIOS won't be used, and if you
1777 choose "MMConfig", then PCI Express MMCONFIG will be used.
1778 If you choose "Any", the kernel will try MMCONFIG, then the
1779 direct access method and falls back to the BIOS if that doesn't
1780 work. If unsure, go with the default, which is "Any".
1785 config PCI_GOMMCONFIG
1802 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1804 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1807 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1811 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1815 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1822 bool "Support mmconfig PCI config space access"
1823 depends on X86_64 && PCI && ACPI
1826 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1827 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1829 DMA remapping (DMAR) devices support enables independent address
1830 translations for Direct Memory Access (DMA) from devices.
1831 These DMA remapping devices are reported via ACPI tables
1832 and include PCI device scope covered by these DMA
1835 config DMAR_DEFAULT_ON
1837 prompt "Enable DMA Remapping Devices by default"
1840 Selecting this option will enable a DMAR device at boot time if
1841 one is found. If this option is not selected, DMAR support can
1842 be enabled by passing intel_iommu=on to the kernel. It is
1843 recommended you say N here while the DMAR code remains
1848 prompt "Support for Graphics workaround"
1851 Current Graphics drivers tend to use physical address
1852 for DMA and avoid using DMA APIs. Setting this config
1853 option permits the IOMMU driver to set a unity map for
1854 all the OS-visible memory. Hence the driver can continue
1855 to use physical addresses for DMA.
1857 config DMAR_FLOPPY_WA
1861 Floppy disk drivers are know to bypass DMA API calls
1862 thereby failing to work when IOMMU is enabled. This
1863 workaround will setup a 1:1 mapping for the first
1864 16M to make floppy (an ISA device) work.
1867 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1868 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1871 Supports Interrupt remapping for IO-APIC and MSI devices.
1872 To use x2apic mode in the CPU's which support x2APIC enhancements or
1873 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1875 source "drivers/pci/pcie/Kconfig"
1877 source "drivers/pci/Kconfig"
1879 # x86_64 have no ISA slots, but do have ISA-style DMA.
1888 Find out whether you have ISA slots on your motherboard. ISA is the
1889 name of a bus system, i.e. the way the CPU talks to the other stuff
1890 inside your box. Other bus systems are PCI, EISA, MicroChannel
1891 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1892 newer boards don't support it. If you have ISA, say Y, otherwise N.
1898 The Extended Industry Standard Architecture (EISA) bus was
1899 developed as an open alternative to the IBM MicroChannel bus.
1901 The EISA bus provided some of the features of the IBM MicroChannel
1902 bus while maintaining backward compatibility with cards made for
1903 the older ISA bus. The EISA bus saw limited use between 1988 and
1904 1995 when it was made obsolete by the PCI bus.
1906 Say Y here if you are building a kernel for an EISA-based machine.
1910 source "drivers/eisa/Kconfig"
1915 MicroChannel Architecture is found in some IBM PS/2 machines and
1916 laptops. It is a bus system similar to PCI or ISA. See
1917 <file:Documentation/mca.txt> (and especially the web page given
1918 there) before attempting to build an MCA bus kernel.
1920 source "drivers/mca/Kconfig"
1923 tristate "NatSemi SCx200 support"
1925 This provides basic support for National Semiconductor's
1926 (now AMD's) Geode processors. The driver probes for the
1927 PCI-IDs of several on-chip devices, so its a good dependency
1928 for other scx200_* drivers.
1930 If compiled as a module, the driver is named scx200.
1932 config SCx200HR_TIMER
1933 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1934 depends on SCx200 && GENERIC_TIME
1937 This driver provides a clocksource built upon the on-chip
1938 27MHz high-resolution timer. Its also a workaround for
1939 NSC Geode SC-1100's buggy TSC, which loses time when the
1940 processor goes idle (as is done by the scheduler). The
1941 other workaround is idle=poll boot option.
1943 config GEODE_MFGPT_TIMER
1945 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1946 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1948 This driver provides a clock event source based on the MFGPT
1949 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1950 MFGPTs have a better resolution and max interval than the
1951 generic PIT, and are suitable for use as high-res timers.
1954 bool "One Laptop Per Child support"
1957 Add support for detecting the unique features of the OLPC
1964 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1966 source "drivers/pcmcia/Kconfig"
1968 source "drivers/pci/hotplug/Kconfig"
1973 menu "Executable file formats / Emulations"
1975 source "fs/Kconfig.binfmt"
1977 config IA32_EMULATION
1978 bool "IA32 Emulation"
1980 select COMPAT_BINFMT_ELF
1982 Include code to run 32-bit programs under a 64-bit kernel. You should
1983 likely turn this on, unless you're 100% sure that you don't have any
1984 32-bit programs left.
1987 tristate "IA32 a.out support"
1988 depends on IA32_EMULATION
1990 Support old a.out binaries in the 32bit emulation.
1994 depends on IA32_EMULATION
1996 config COMPAT_FOR_U64_ALIGNMENT
2000 config SYSVIPC_COMPAT
2002 depends on COMPAT && SYSVIPC
2007 config HAVE_ATOMIC_IOMAP
2011 source "net/Kconfig"
2013 source "drivers/Kconfig"
2015 source "drivers/firmware/Kconfig"
2019 source "arch/x86/Kconfig.debug"
2021 source "security/Kconfig"
2023 source "crypto/Kconfig"
2025 source "arch/x86/kvm/Kconfig"
2027 source "lib/Kconfig"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blob