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
37 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
38 select HAVE_FTRACE_SYSCALLS
41 select HAVE_ARCH_TRACEHOOK
42 select HAVE_GENERIC_DMA_COHERENT if X86_32
43 select HAVE_EFFICIENT_UNALIGNED_ACCESS
44 select USER_STACKTRACE_SUPPORT
45 select HAVE_KERNEL_GZIP
46 select HAVE_KERNEL_BZIP2
47 select HAVE_KERNEL_LZMA
51 default "arch/x86/configs/i386_defconfig" if X86_32
52 default "arch/x86/configs/x86_64_defconfig" if X86_64
57 config GENERIC_CMOS_UPDATE
60 config CLOCKSOURCE_WATCHDOG
63 config GENERIC_CLOCKEVENTS
66 config GENERIC_CLOCKEVENTS_BROADCAST
68 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
70 config LOCKDEP_SUPPORT
73 config STACKTRACE_SUPPORT
76 config HAVE_LATENCYTOP_SUPPORT
79 config FAST_CMPXCHG_LOCAL
92 config GENERIC_ISA_DMA
101 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
103 config GENERIC_BUG_RELATIVE_POINTERS
106 config GENERIC_HWEIGHT
112 config ARCH_MAY_HAVE_PC_FDC
115 config RWSEM_GENERIC_SPINLOCK
118 config RWSEM_XCHGADD_ALGORITHM
121 config ARCH_HAS_CPU_IDLE_WAIT
124 config GENERIC_CALIBRATE_DELAY
127 config GENERIC_TIME_VSYSCALL
131 config ARCH_HAS_CPU_RELAX
134 config ARCH_HAS_DEFAULT_IDLE
137 config ARCH_HAS_CACHE_LINE_SIZE
140 config HAVE_SETUP_PER_CPU_AREA
143 config HAVE_DYNAMIC_PER_CPU_AREA
146 config HAVE_CPUMASK_OF_CPU_MAP
149 config ARCH_HIBERNATION_POSSIBLE
152 config ARCH_SUSPEND_POSSIBLE
159 config ARCH_POPULATES_NODE_MAP
166 config ARCH_SUPPORTS_OPTIMIZED_INLINING
169 # Use the generic interrupt handling code in kernel/irq/:
170 config GENERIC_HARDIRQS
174 config GENERIC_IRQ_PROBE
178 config GENERIC_PENDING_IRQ
180 depends on GENERIC_HARDIRQS && SMP
183 config USE_GENERIC_SMP_HELPERS
189 depends on X86_32 && SMP
193 depends on X86_64 && SMP
200 config X86_TRAMPOLINE
202 depends on SMP || (64BIT && ACPI_SLEEP)
205 config X86_32_LAZY_GS
207 depends on X86_32 && !CC_STACKPROTECTOR
211 source "init/Kconfig"
212 source "kernel/Kconfig.freezer"
214 menu "Processor type and features"
216 source "kernel/time/Kconfig"
219 bool "Symmetric multi-processing support"
221 This enables support for systems with more than one CPU. If you have
222 a system with only one CPU, like most personal computers, say N. If
223 you have a system with more than one CPU, say Y.
225 If you say N here, the kernel will run on single and multiprocessor
226 machines, but will use only one CPU of a multiprocessor machine. If
227 you say Y here, the kernel will run on many, but not all,
228 singleprocessor machines. On a singleprocessor machine, the kernel
229 will run faster if you say N here.
231 Note that if you say Y here and choose architecture "586" or
232 "Pentium" under "Processor family", the kernel will not work on 486
233 architectures. Similarly, multiprocessor kernels for the "PPro"
234 architecture may not work on all Pentium based boards.
236 People using multiprocessor machines who say Y here should also say
237 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
238 Management" code will be disabled if you say Y here.
240 See also <file:Documentation/i386/IO-APIC.txt>,
241 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
242 <http://www.tldp.org/docs.html#howto>.
244 If you don't know what to do here, say N.
247 bool "Support x2apic"
248 depends on X86_LOCAL_APIC && X86_64
250 This enables x2apic support on CPUs that have this feature.
252 This allows 32-bit apic IDs (so it can support very large systems),
253 and accesses the local apic via MSRs not via mmio.
255 ( On certain CPU models you may need to enable INTR_REMAP too,
256 to get functional x2apic mode. )
258 If you don't know what to do here, say N.
261 bool "Support sparse irq numbering"
262 depends on PCI_MSI || HT_IRQ
264 This enables support for sparse irqs. This is useful for distro
265 kernels that want to define a high CONFIG_NR_CPUS value but still
266 want to have low kernel memory footprint on smaller machines.
268 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
269 out the irq_desc[] array in a more NUMA-friendly way. )
271 If you don't know what to do here, say N.
273 config NUMA_MIGRATE_IRQ_DESC
274 bool "Move irq desc when changing irq smp_affinity"
275 depends on SPARSE_IRQ && NUMA
278 This enables moving irq_desc to cpu/node that irq will use handled.
280 If you don't know what to do here, say N.
283 bool "Enable MPS table" if ACPI
285 depends on X86_LOCAL_APIC
287 For old smp systems that do not have proper acpi support. Newer systems
288 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
291 bool "Support for big SMP systems with more than 8 CPUs"
292 depends on X86_32 && SMP
294 This option is needed for the systems that have more than 8 CPUs
297 config X86_EXTENDED_PLATFORM
298 bool "Support for extended (non-PC) x86 platforms"
301 If you disable this option then the kernel will only support
302 standard PC platforms. (which covers the vast majority of
305 If you enable this option then you'll be able to select support
306 for the following (non-PC) 32 bit x86 platforms:
310 SGI 320/540 (Visual Workstation)
311 Summit/EXA (IBM x440)
312 Unisys ES7000 IA32 series
314 If you have one of these systems, or if you want to build a
315 generic distribution kernel, say Y here - otherwise say N.
319 config X86_EXTENDED_PLATFORM
320 bool "Support for extended (non-PC) x86 platforms"
323 If you disable this option then the kernel will only support
324 standard PC platforms. (which covers the vast majority of
327 If you enable this option then you'll be able to select support
328 for the following (non-PC) 64 bit x86 platforms:
332 If you have one of these systems, or if you want to build a
333 generic distribution kernel, say Y here - otherwise say N.
335 # This is an alphabetically sorted list of 64 bit extended platforms
336 # Please maintain the alphabetic order if and when there are additions
341 depends on X86_64 && PCI
342 depends on X86_EXTENDED_PLATFORM
344 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
345 supposed to run on these EM64T-based machines. Only choose this option
346 if you have one of these machines.
349 bool "SGI Ultraviolet"
351 depends on X86_EXTENDED_PLATFORM
354 This option is needed in order to support SGI Ultraviolet systems.
355 If you don't have one of these, you should say N here.
357 # Following is an alphabetically sorted list of 32 bit extended platforms
358 # Please maintain the alphabetic order if and when there are additions
363 depends on X86_EXTENDED_PLATFORM
365 Select this for an AMD Elan processor.
367 Do not use this option for K6/Athlon/Opteron processors!
369 If unsure, choose "PC-compatible" instead.
372 bool "RDC R-321x SoC"
374 depends on X86_EXTENDED_PLATFORM
376 select X86_REBOOTFIXUPS
378 This option is needed for RDC R-321x system-on-chip, also known
380 If you don't have one of these chips, you should say N here.
382 config X86_32_NON_STANDARD
383 bool "Support non-standard 32-bit SMP architectures"
384 depends on X86_32 && SMP
385 depends on X86_EXTENDED_PLATFORM
387 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
388 subarchitectures. It is intended for a generic binary kernel.
389 if you select them all, kernel will probe it one by one. and will
392 # Alphabetically sorted list of Non standard 32 bit platforms
395 bool "NUMAQ (IBM/Sequent)"
396 depends on X86_32_NON_STANDARD
400 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
401 NUMA multiquad box. This changes the way that processors are
402 bootstrapped, and uses Clustered Logical APIC addressing mode instead
403 of Flat Logical. You will need a new lynxer.elf file to flash your
404 firmware with - send email to <Martin.Bligh@us.ibm.com>.
407 bool "SGI 320/540 (Visual Workstation)"
408 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
409 depends on X86_32_NON_STANDARD
411 The SGI Visual Workstation series is an IA32-based workstation
412 based on SGI systems chips with some legacy PC hardware attached.
414 Say Y here to create a kernel to run on the SGI 320 or 540.
416 A kernel compiled for the Visual Workstation will run on general
417 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
420 bool "Summit/EXA (IBM x440)"
421 depends on X86_32_NON_STANDARD
423 This option is needed for IBM systems that use the Summit/EXA chipset.
424 In particular, it is needed for the x440.
427 bool "Unisys ES7000 IA32 series"
428 depends on X86_32_NON_STANDARD && X86_BIGSMP
430 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
431 supposed to run on an IA32-based Unisys ES7000 system.
433 config SCHED_OMIT_FRAME_POINTER
435 prompt "Single-depth WCHAN output"
438 Calculate simpler /proc/<PID>/wchan values. If this option
439 is disabled then wchan values will recurse back to the
440 caller function. This provides more accurate wchan values,
441 at the expense of slightly more scheduling overhead.
443 If in doubt, say "Y".
445 menuconfig PARAVIRT_GUEST
446 bool "Paravirtualized guest support"
448 Say Y here to get to see options related to running Linux under
449 various hypervisors. This option alone does not add any kernel code.
451 If you say N, all options in this submenu will be skipped and disabled.
455 source "arch/x86/xen/Kconfig"
458 bool "VMI Guest support"
462 VMI provides a paravirtualized interface to the VMware ESX server
463 (it could be used by other hypervisors in theory too, but is not
464 at the moment), by linking the kernel to a GPL-ed ROM module
465 provided by the hypervisor.
468 bool "KVM paravirtualized clock"
470 select PARAVIRT_CLOCK
472 Turning on this option will allow you to run a paravirtualized clock
473 when running over the KVM hypervisor. Instead of relying on a PIT
474 (or probably other) emulation by the underlying device model, the host
475 provides the guest with timing infrastructure such as time of day, and
479 bool "KVM Guest support"
482 This option enables various optimizations for running under the KVM
485 source "arch/x86/lguest/Kconfig"
488 bool "Enable paravirtualization code"
490 This changes the kernel so it can modify itself when it is run
491 under a hypervisor, potentially improving performance significantly
492 over full virtualization. However, when run without a hypervisor
493 the kernel is theoretically slower and slightly larger.
495 config PARAVIRT_CLOCK
501 config PARAVIRT_DEBUG
502 bool "paravirt-ops debugging"
503 depends on PARAVIRT && DEBUG_KERNEL
505 Enable to debug paravirt_ops internals. Specifically, BUG if
506 a paravirt_op is missing when it is called.
511 This option adds a kernel parameter 'memtest', which allows memtest
513 memtest=0, mean disabled; -- default
514 memtest=1, mean do 1 test pattern;
516 memtest=4, mean do 4 test patterns.
517 If you are unsure how to answer this question, answer N.
519 config X86_SUMMIT_NUMA
521 depends on X86_32 && NUMA && X86_32_NON_STANDARD
523 config X86_CYCLONE_TIMER
525 depends on X86_32_NON_STANDARD
527 source "arch/x86/Kconfig.cpu"
531 prompt "HPET Timer Support" if X86_32
533 Use the IA-PC HPET (High Precision Event Timer) to manage
534 time in preference to the PIT and RTC, if a HPET is
536 HPET is the next generation timer replacing legacy 8254s.
537 The HPET provides a stable time base on SMP
538 systems, unlike the TSC, but it is more expensive to access,
539 as it is off-chip. You can find the HPET spec at
540 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
542 You can safely choose Y here. However, HPET will only be
543 activated if the platform and the BIOS support this feature.
544 Otherwise the 8254 will be used for timing services.
546 Choose N to continue using the legacy 8254 timer.
548 config HPET_EMULATE_RTC
550 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
552 # Mark as embedded because too many people got it wrong.
553 # The code disables itself when not needed.
556 bool "Enable DMI scanning" if EMBEDDED
558 Enabled scanning of DMI to identify machine quirks. Say Y
559 here unless you have verified that your setup is not
560 affected by entries in the DMI blacklist. Required by PNP
564 bool "GART IOMMU support" if EMBEDDED
568 depends on X86_64 && PCI
570 Support for full DMA access of devices with 32bit memory access only
571 on systems with more than 3GB. This is usually needed for USB,
572 sound, many IDE/SATA chipsets and some other devices.
573 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
574 based hardware IOMMU and a software bounce buffer based IOMMU used
575 on Intel systems and as fallback.
576 The code is only active when needed (enough memory and limited
577 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
581 bool "IBM Calgary IOMMU support"
583 depends on X86_64 && PCI && EXPERIMENTAL
585 Support for hardware IOMMUs in IBM's xSeries x366 and x460
586 systems. Needed to run systems with more than 3GB of memory
587 properly with 32-bit PCI devices that do not support DAC
588 (Double Address Cycle). Calgary also supports bus level
589 isolation, where all DMAs pass through the IOMMU. This
590 prevents them from going anywhere except their intended
591 destination. This catches hard-to-find kernel bugs and
592 mis-behaving drivers and devices that do not use the DMA-API
593 properly to set up their DMA buffers. The IOMMU can be
594 turned off at boot time with the iommu=off parameter.
595 Normally the kernel will make the right choice by itself.
598 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
600 prompt "Should Calgary be enabled by default?"
601 depends on CALGARY_IOMMU
603 Should Calgary be enabled by default? if you choose 'y', Calgary
604 will be used (if it exists). If you choose 'n', Calgary will not be
605 used even if it exists. If you choose 'n' and would like to use
606 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
610 bool "AMD IOMMU support"
613 depends on X86_64 && PCI && ACPI
615 With this option you can enable support for AMD IOMMU hardware in
616 your system. An IOMMU is a hardware component which provides
617 remapping of DMA memory accesses from devices. With an AMD IOMMU you
618 can isolate the the DMA memory of different devices and protect the
619 system from misbehaving device drivers or hardware.
621 You can find out if your system has an AMD IOMMU if you look into
622 your BIOS for an option to enable it or if you have an IVRS ACPI
625 config AMD_IOMMU_STATS
626 bool "Export AMD IOMMU statistics to debugfs"
630 This option enables code in the AMD IOMMU driver to collect various
631 statistics about whats happening in the driver and exports that
632 information to userspace via debugfs.
635 # need this always selected by IOMMU for the VIA workaround
639 Support for software bounce buffers used on x86-64 systems
640 which don't have a hardware IOMMU (e.g. the current generation
641 of Intel's x86-64 CPUs). Using this PCI devices which can only
642 access 32-bits of memory can be used on systems with more than
643 3 GB of memory. If unsure, say Y.
646 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
649 def_bool (AMD_IOMMU || DMAR)
652 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
653 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
654 select CPUMASK_OFFSTACK
657 Configure maximum number of CPUS and NUMA Nodes for this architecture.
661 int "Maximum number of CPUs" if SMP && !MAXSMP
662 range 2 512 if SMP && !MAXSMP
664 default "4096" if MAXSMP
665 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
668 This allows you to specify the maximum number of CPUs which this
669 kernel will support. The maximum supported value is 512 and the
670 minimum value which makes sense is 2.
672 This is purely to save memory - each supported CPU adds
673 approximately eight kilobytes to the kernel image.
676 bool "SMT (Hyperthreading) scheduler support"
679 SMT scheduler support improves the CPU scheduler's decision making
680 when dealing with Intel Pentium 4 chips with HyperThreading at a
681 cost of slightly increased overhead in some places. If unsure say
686 prompt "Multi-core scheduler support"
689 Multi-core scheduler support improves the CPU scheduler's decision
690 making when dealing with multi-core CPU chips at a cost of slightly
691 increased overhead in some places. If unsure say N here.
693 source "kernel/Kconfig.preempt"
696 bool "Local APIC support on uniprocessors"
697 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
699 A local APIC (Advanced Programmable Interrupt Controller) is an
700 integrated interrupt controller in the CPU. If you have a single-CPU
701 system which has a processor with a local APIC, you can say Y here to
702 enable and use it. If you say Y here even though your machine doesn't
703 have a local APIC, then the kernel will still run with no slowdown at
704 all. The local APIC supports CPU-generated self-interrupts (timer,
705 performance counters), and the NMI watchdog which detects hard
709 bool "IO-APIC support on uniprocessors"
710 depends on X86_UP_APIC
712 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
713 SMP-capable replacement for PC-style interrupt controllers. Most
714 SMP systems and many recent uniprocessor systems have one.
716 If you have a single-CPU system with an IO-APIC, you can say Y here
717 to use it. If you say Y here even though your machine doesn't have
718 an IO-APIC, then the kernel will still run with no slowdown at all.
720 config X86_LOCAL_APIC
722 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
726 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
728 config X86_VISWS_APIC
730 depends on X86_32 && X86_VISWS
732 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
733 bool "Reroute for broken boot IRQs"
735 depends on X86_IO_APIC
737 This option enables a workaround that fixes a source of
738 spurious interrupts. This is recommended when threaded
739 interrupt handling is used on systems where the generation of
740 superfluous "boot interrupts" cannot be disabled.
742 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
743 entry in the chipset's IO-APIC is masked (as, e.g. the RT
744 kernel does during interrupt handling). On chipsets where this
745 boot IRQ generation cannot be disabled, this workaround keeps
746 the original IRQ line masked so that only the equivalent "boot
747 IRQ" is delivered to the CPUs. The workaround also tells the
748 kernel to set up the IRQ handler on the boot IRQ line. In this
749 way only one interrupt is delivered to the kernel. Otherwise
750 the spurious second interrupt may cause the kernel to bring
751 down (vital) interrupt lines.
753 Only affects "broken" chipsets. Interrupt sharing may be
754 increased on these systems.
757 bool "Machine Check Exception"
759 Machine Check Exception support allows the processor to notify the
760 kernel if it detects a problem (e.g. overheating, component failure).
761 The action the kernel takes depends on the severity of the problem,
762 ranging from a warning message on the console, to halting the machine.
763 Your processor must be a Pentium or newer to support this - check the
764 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
765 have a design flaw which leads to false MCE events - hence MCE is
766 disabled on all P5 processors, unless explicitly enabled with "mce"
767 as a boot argument. Similarly, if MCE is built in and creates a
768 problem on some new non-standard machine, you can boot with "nomce"
769 to disable it. MCE support simply ignores non-MCE processors like
770 the 386 and 486, so nearly everyone can say Y here.
774 prompt "Intel MCE features"
775 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
777 Additional support for intel specific MCE features such as
782 prompt "AMD MCE features"
783 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
785 Additional support for AMD specific MCE features such as
786 the DRAM Error Threshold.
788 config X86_MCE_THRESHOLD
789 depends on X86_MCE_AMD || X86_MCE_INTEL
793 config X86_MCE_NONFATAL
794 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
795 depends on X86_32 && X86_MCE
797 Enabling this feature starts a timer that triggers every 5 seconds which
798 will look at the machine check registers to see if anything happened.
799 Non-fatal problems automatically get corrected (but still logged).
800 Disable this if you don't want to see these messages.
801 Seeing the messages this option prints out may be indicative of dying
802 or out-of-spec (ie, overclocked) hardware.
803 This option only does something on certain CPUs.
804 (AMD Athlon/Duron and Intel Pentium 4)
806 config X86_MCE_P4THERMAL
807 bool "check for P4 thermal throttling interrupt."
808 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
810 Enabling this feature will cause a message to be printed when the P4
811 enters thermal throttling.
814 bool "Enable VM86 support" if EMBEDDED
818 This option is required by programs like DOSEMU to run 16-bit legacy
819 code on X86 processors. It also may be needed by software like
820 XFree86 to initialize some video cards via BIOS. Disabling this
821 option saves about 6k.
824 tristate "Toshiba Laptop support"
827 This adds a driver to safely access the System Management Mode of
828 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
829 not work on models with a Phoenix BIOS. The System Management Mode
830 is used to set the BIOS and power saving options on Toshiba portables.
832 For information on utilities to make use of this driver see the
833 Toshiba Linux utilities web site at:
834 <http://www.buzzard.org.uk/toshiba/>.
836 Say Y if you intend to run this kernel on a Toshiba portable.
840 tristate "Dell laptop support"
842 This adds a driver to safely access the System Management Mode
843 of the CPU on the Dell Inspiron 8000. The System Management Mode
844 is used to read cpu temperature and cooling fan status and to
845 control the fans on the I8K portables.
847 This driver has been tested only on the Inspiron 8000 but it may
848 also work with other Dell laptops. You can force loading on other
849 models by passing the parameter `force=1' to the module. Use at
852 For information on utilities to make use of this driver see the
853 I8K Linux utilities web site at:
854 <http://people.debian.org/~dz/i8k/>
856 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
859 config X86_REBOOTFIXUPS
860 bool "Enable X86 board specific fixups for reboot"
863 This enables chipset and/or board specific fixups to be done
864 in order to get reboot to work correctly. This is only needed on
865 some combinations of hardware and BIOS. The symptom, for which
866 this config is intended, is when reboot ends with a stalled/hung
869 Currently, the only fixup is for the Geode machines using
870 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
872 Say Y if you want to enable the fixup. Currently, it's safe to
873 enable this option even if you don't need it.
877 tristate "/dev/cpu/microcode - microcode support"
880 If you say Y here, you will be able to update the microcode on
881 certain Intel and AMD processors. The Intel support is for the
882 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
883 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
884 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
885 You will obviously need the actual microcode binary data itself
886 which is not shipped with the Linux kernel.
888 This option selects the general module only, you need to select
889 at least one vendor specific module as well.
891 To compile this driver as a module, choose M here: the
892 module will be called microcode.
894 config MICROCODE_INTEL
895 bool "Intel microcode patch loading support"
900 This options enables microcode patch loading support for Intel
903 For latest news and information on obtaining all the required
904 Intel ingredients for this driver, check:
905 <http://www.urbanmyth.org/microcode/>.
908 bool "AMD microcode patch loading support"
912 If you select this option, microcode patch loading support for AMD
913 processors will be enabled.
915 config MICROCODE_OLD_INTERFACE
920 tristate "/dev/cpu/*/msr - Model-specific register support"
922 This device gives privileged processes access to the x86
923 Model-Specific Registers (MSRs). It is a character device with
924 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
925 MSR accesses are directed to a specific CPU on multi-processor
929 tristate "/dev/cpu/*/cpuid - CPU information support"
931 This device gives processes access to the x86 CPUID instruction to
932 be executed on a specific processor. It is a character device
933 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
937 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
939 If you select this option, this will provide various x86 CPUs
940 information through debugfs.
943 prompt "High Memory Support"
944 default HIGHMEM4G if !X86_NUMAQ
945 default HIGHMEM64G if X86_NUMAQ
950 depends on !X86_NUMAQ
952 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
953 However, the address space of 32-bit x86 processors is only 4
954 Gigabytes large. That means that, if you have a large amount of
955 physical memory, not all of it can be "permanently mapped" by the
956 kernel. The physical memory that's not permanently mapped is called
959 If you are compiling a kernel which will never run on a machine with
960 more than 1 Gigabyte total physical RAM, answer "off" here (default
961 choice and suitable for most users). This will result in a "3GB/1GB"
962 split: 3GB are mapped so that each process sees a 3GB virtual memory
963 space and the remaining part of the 4GB virtual memory space is used
964 by the kernel to permanently map as much physical memory as
967 If the machine has between 1 and 4 Gigabytes physical RAM, then
970 If more than 4 Gigabytes is used then answer "64GB" here. This
971 selection turns Intel PAE (Physical Address Extension) mode on.
972 PAE implements 3-level paging on IA32 processors. PAE is fully
973 supported by Linux, PAE mode is implemented on all recent Intel
974 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
975 then the kernel will not boot on CPUs that don't support PAE!
977 The actual amount of total physical memory will either be
978 auto detected or can be forced by using a kernel command line option
979 such as "mem=256M". (Try "man bootparam" or see the documentation of
980 your boot loader (lilo or loadlin) about how to pass options to the
981 kernel at boot time.)
983 If unsure, say "off".
987 depends on !X86_NUMAQ
989 Select this if you have a 32-bit processor and between 1 and 4
990 gigabytes of physical RAM.
994 depends on !M386 && !M486
997 Select this if you have a 32-bit processor and more than 4
998 gigabytes of physical RAM.
1003 depends on EXPERIMENTAL
1004 prompt "Memory split" if EMBEDDED
1008 Select the desired split between kernel and user memory.
1010 If the address range available to the kernel is less than the
1011 physical memory installed, the remaining memory will be available
1012 as "high memory". Accessing high memory is a little more costly
1013 than low memory, as it needs to be mapped into the kernel first.
1014 Note that increasing the kernel address space limits the range
1015 available to user programs, making the address space there
1016 tighter. Selecting anything other than the default 3G/1G split
1017 will also likely make your kernel incompatible with binary-only
1020 If you are not absolutely sure what you are doing, leave this
1024 bool "3G/1G user/kernel split"
1025 config VMSPLIT_3G_OPT
1027 bool "3G/1G user/kernel split (for full 1G low memory)"
1029 bool "2G/2G user/kernel split"
1030 config VMSPLIT_2G_OPT
1032 bool "2G/2G user/kernel split (for full 2G low memory)"
1034 bool "1G/3G user/kernel split"
1039 default 0xB0000000 if VMSPLIT_3G_OPT
1040 default 0x80000000 if VMSPLIT_2G
1041 default 0x78000000 if VMSPLIT_2G_OPT
1042 default 0x40000000 if VMSPLIT_1G
1048 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1051 bool "PAE (Physical Address Extension) Support"
1052 depends on X86_32 && !HIGHMEM4G
1054 PAE is required for NX support, and furthermore enables
1055 larger swapspace support for non-overcommit purposes. It
1056 has the cost of more pagetable lookup overhead, and also
1057 consumes more pagetable space per process.
1059 config ARCH_PHYS_ADDR_T_64BIT
1060 def_bool X86_64 || X86_PAE
1062 config DIRECT_GBPAGES
1063 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1067 Allow the kernel linear mapping to use 1GB pages on CPUs that
1068 support it. This can improve the kernel's performance a tiny bit by
1069 reducing TLB pressure. If in doubt, say "Y".
1071 # Common NUMA Features
1073 bool "Numa Memory Allocation and Scheduler Support"
1075 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1076 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1078 Enable NUMA (Non Uniform Memory Access) support.
1080 The kernel will try to allocate memory used by a CPU on the
1081 local memory controller of the CPU and add some more
1082 NUMA awareness to the kernel.
1084 For 64-bit this is recommended if the system is Intel Core i7
1085 (or later), AMD Opteron, or EM64T NUMA.
1087 For 32-bit this is only needed on (rare) 32-bit-only platforms
1088 that support NUMA topologies, such as NUMAQ / Summit, or if you
1089 boot a 32-bit kernel on a 64-bit NUMA platform.
1091 Otherwise, you should say N.
1093 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1094 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1098 prompt "Old style AMD Opteron NUMA detection"
1099 depends on X86_64 && NUMA && PCI
1101 Enable K8 NUMA node topology detection. You should say Y here if
1102 you have a multi processor AMD K8 system. This uses an old
1103 method to read the NUMA configuration directly from the builtin
1104 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1105 instead, which also takes priority if both are compiled in.
1107 config X86_64_ACPI_NUMA
1109 prompt "ACPI NUMA detection"
1110 depends on X86_64 && NUMA && ACPI && PCI
1113 Enable ACPI SRAT based node topology detection.
1115 # Some NUMA nodes have memory ranges that span
1116 # other nodes. Even though a pfn is valid and
1117 # between a node's start and end pfns, it may not
1118 # reside on that node. See memmap_init_zone()
1120 config NODES_SPAN_OTHER_NODES
1122 depends on X86_64_ACPI_NUMA
1125 bool "NUMA emulation"
1126 depends on X86_64 && NUMA
1128 Enable NUMA emulation. A flat machine will be split
1129 into virtual nodes when booted with "numa=fake=N", where N is the
1130 number of nodes. This is only useful for debugging.
1133 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1135 default "9" if MAXSMP
1136 default "6" if X86_64
1137 default "4" if X86_NUMAQ
1139 depends on NEED_MULTIPLE_NODES
1141 Specify the maximum number of NUMA Nodes available on the target
1142 system. Increases memory reserved to accomodate various tables.
1144 config HAVE_ARCH_BOOTMEM
1146 depends on X86_32 && NUMA
1148 config ARCH_HAVE_MEMORY_PRESENT
1150 depends on X86_32 && DISCONTIGMEM
1152 config NEED_NODE_MEMMAP_SIZE
1154 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1156 config HAVE_ARCH_ALLOC_REMAP
1158 depends on X86_32 && NUMA
1160 config ARCH_FLATMEM_ENABLE
1162 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1164 config ARCH_DISCONTIGMEM_ENABLE
1166 depends on NUMA && X86_32
1168 config ARCH_DISCONTIGMEM_DEFAULT
1170 depends on NUMA && X86_32
1172 config ARCH_SPARSEMEM_DEFAULT
1176 config ARCH_SPARSEMEM_ENABLE
1178 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1179 select SPARSEMEM_STATIC if X86_32
1180 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1182 config ARCH_SELECT_MEMORY_MODEL
1184 depends on ARCH_SPARSEMEM_ENABLE
1186 config ARCH_MEMORY_PROBE
1188 depends on MEMORY_HOTPLUG
1193 bool "Allocate 3rd-level pagetables from highmem"
1194 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1196 The VM uses one page table entry for each page of physical memory.
1197 For systems with a lot of RAM, this can be wasteful of precious
1198 low memory. Setting this option will put user-space page table
1199 entries in high memory.
1201 config X86_CHECK_BIOS_CORRUPTION
1202 bool "Check for low memory corruption"
1204 Periodically check for memory corruption in low memory, which
1205 is suspected to be caused by BIOS. Even when enabled in the
1206 configuration, it is disabled at runtime. Enable it by
1207 setting "memory_corruption_check=1" on the kernel command
1208 line. By default it scans the low 64k of memory every 60
1209 seconds; see the memory_corruption_check_size and
1210 memory_corruption_check_period parameters in
1211 Documentation/kernel-parameters.txt to adjust this.
1213 When enabled with the default parameters, this option has
1214 almost no overhead, as it reserves a relatively small amount
1215 of memory and scans it infrequently. It both detects corruption
1216 and prevents it from affecting the running system.
1218 It is, however, intended as a diagnostic tool; if repeatable
1219 BIOS-originated corruption always affects the same memory,
1220 you can use memmap= to prevent the kernel from using that
1223 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1224 bool "Set the default setting of memory_corruption_check"
1225 depends on X86_CHECK_BIOS_CORRUPTION
1228 Set whether the default state of memory_corruption_check is
1231 config X86_RESERVE_LOW_64K
1232 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1235 Reserve the first 64K of physical RAM on BIOSes that are known
1236 to potentially corrupt that memory range. A numbers of BIOSes are
1237 known to utilize this area during suspend/resume, so it must not
1238 be used by the kernel.
1240 Set this to N if you are absolutely sure that you trust the BIOS
1241 to get all its memory reservations and usages right.
1243 If you have doubts about the BIOS (e.g. suspend/resume does not
1244 work or there's kernel crashes after certain hardware hotplug
1245 events) and it's not AMI or Phoenix, then you might want to enable
1246 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1247 corruption patterns.
1251 config MATH_EMULATION
1253 prompt "Math emulation" if X86_32
1255 Linux can emulate a math coprocessor (used for floating point
1256 operations) if you don't have one. 486DX and Pentium processors have
1257 a math coprocessor built in, 486SX and 386 do not, unless you added
1258 a 487DX or 387, respectively. (The messages during boot time can
1259 give you some hints here ["man dmesg"].) Everyone needs either a
1260 coprocessor or this emulation.
1262 If you don't have a math coprocessor, you need to say Y here; if you
1263 say Y here even though you have a coprocessor, the coprocessor will
1264 be used nevertheless. (This behavior can be changed with the kernel
1265 command line option "no387", which comes handy if your coprocessor
1266 is broken. Try "man bootparam" or see the documentation of your boot
1267 loader (lilo or loadlin) about how to pass options to the kernel at
1268 boot time.) This means that it is a good idea to say Y here if you
1269 intend to use this kernel on different machines.
1271 More information about the internals of the Linux math coprocessor
1272 emulation can be found in <file:arch/x86/math-emu/README>.
1274 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1275 kernel, it won't hurt.
1278 bool "MTRR (Memory Type Range Register) support"
1280 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1281 the Memory Type Range Registers (MTRRs) may be used to control
1282 processor access to memory ranges. This is most useful if you have
1283 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1284 allows bus write transfers to be combined into a larger transfer
1285 before bursting over the PCI/AGP bus. This can increase performance
1286 of image write operations 2.5 times or more. Saying Y here creates a
1287 /proc/mtrr file which may be used to manipulate your processor's
1288 MTRRs. Typically the X server should use this.
1290 This code has a reasonably generic interface so that similar
1291 control registers on other processors can be easily supported
1294 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1295 Registers (ARRs) which provide a similar functionality to MTRRs. For
1296 these, the ARRs are used to emulate the MTRRs.
1297 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1298 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1299 write-combining. All of these processors are supported by this code
1300 and it makes sense to say Y here if you have one of them.
1302 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1303 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1304 can lead to all sorts of problems, so it's good to say Y here.
1306 You can safely say Y even if your machine doesn't have MTRRs, you'll
1307 just add about 9 KB to your kernel.
1309 See <file:Documentation/x86/mtrr.txt> for more information.
1311 config MTRR_SANITIZER
1313 prompt "MTRR cleanup support"
1316 Convert MTRR layout from continuous to discrete, so X drivers can
1317 add writeback entries.
1319 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1320 The largest mtrr entry size for a continous block can be set with
1325 config MTRR_SANITIZER_ENABLE_DEFAULT
1326 int "MTRR cleanup enable value (0-1)"
1329 depends on MTRR_SANITIZER
1331 Enable mtrr cleanup default value
1333 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1334 int "MTRR cleanup spare reg num (0-7)"
1337 depends on MTRR_SANITIZER
1339 mtrr cleanup spare entries default, it can be changed via
1340 mtrr_spare_reg_nr=N on the kernel command line.
1344 prompt "x86 PAT support"
1347 Use PAT attributes to setup page level cache control.
1349 PATs are the modern equivalents of MTRRs and are much more
1350 flexible than MTRRs.
1352 Say N here if you see bootup problems (boot crash, boot hang,
1353 spontaneous reboots) or a non-working video driver.
1358 bool "EFI runtime service support"
1361 This enables the kernel to use EFI runtime services that are
1362 available (such as the EFI variable services).
1364 This option is only useful on systems that have EFI firmware.
1365 In addition, you should use the latest ELILO loader available
1366 at <http://elilo.sourceforge.net> in order to take advantage
1367 of EFI runtime services. However, even with this option, the
1368 resultant kernel should continue to boot on existing non-EFI
1373 prompt "Enable seccomp to safely compute untrusted bytecode"
1375 This kernel feature is useful for number crunching applications
1376 that may need to compute untrusted bytecode during their
1377 execution. By using pipes or other transports made available to
1378 the process as file descriptors supporting the read/write
1379 syscalls, it's possible to isolate those applications in
1380 their own address space using seccomp. Once seccomp is
1381 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1382 and the task is only allowed to execute a few safe syscalls
1383 defined by each seccomp mode.
1385 If unsure, say Y. Only embedded should say N here.
1387 config CC_STACKPROTECTOR_ALL
1390 config CC_STACKPROTECTOR
1391 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1392 select CC_STACKPROTECTOR_ALL
1394 This option turns on the -fstack-protector GCC feature. This
1395 feature puts, at the beginning of functions, a canary value on
1396 the stack just before the return address, and validates
1397 the value just before actually returning. Stack based buffer
1398 overflows (that need to overwrite this return address) now also
1399 overwrite the canary, which gets detected and the attack is then
1400 neutralized via a kernel panic.
1402 This feature requires gcc version 4.2 or above, or a distribution
1403 gcc with the feature backported. Older versions are automatically
1404 detected and for those versions, this configuration option is
1405 ignored. (and a warning is printed during bootup)
1407 source kernel/Kconfig.hz
1410 bool "kexec system call"
1412 kexec is a system call that implements the ability to shutdown your
1413 current kernel, and to start another kernel. It is like a reboot
1414 but it is independent of the system firmware. And like a reboot
1415 you can start any kernel with it, not just Linux.
1417 The name comes from the similarity to the exec system call.
1419 It is an ongoing process to be certain the hardware in a machine
1420 is properly shutdown, so do not be surprised if this code does not
1421 initially work for you. It may help to enable device hotplugging
1422 support. As of this writing the exact hardware interface is
1423 strongly in flux, so no good recommendation can be made.
1426 bool "kernel crash dumps"
1427 depends on X86_64 || (X86_32 && HIGHMEM)
1429 Generate crash dump after being started by kexec.
1430 This should be normally only set in special crash dump kernels
1431 which are loaded in the main kernel with kexec-tools into
1432 a specially reserved region and then later executed after
1433 a crash by kdump/kexec. The crash dump kernel must be compiled
1434 to a memory address not used by the main kernel or BIOS using
1435 PHYSICAL_START, or it must be built as a relocatable image
1436 (CONFIG_RELOCATABLE=y).
1437 For more details see Documentation/kdump/kdump.txt
1440 bool "kexec jump (EXPERIMENTAL)"
1441 depends on EXPERIMENTAL
1442 depends on KEXEC && HIBERNATION
1444 Jump between original kernel and kexeced kernel and invoke
1445 code in physical address mode via KEXEC
1447 config PHYSICAL_START
1448 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1449 default "0x1000000" if X86_NUMAQ
1450 default "0x200000" if X86_64
1453 This gives the physical address where the kernel is loaded.
1455 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1456 bzImage will decompress itself to above physical address and
1457 run from there. Otherwise, bzImage will run from the address where
1458 it has been loaded by the boot loader and will ignore above physical
1461 In normal kdump cases one does not have to set/change this option
1462 as now bzImage can be compiled as a completely relocatable image
1463 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1464 address. This option is mainly useful for the folks who don't want
1465 to use a bzImage for capturing the crash dump and want to use a
1466 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1467 to be specifically compiled to run from a specific memory area
1468 (normally a reserved region) and this option comes handy.
1470 So if you are using bzImage for capturing the crash dump, leave
1471 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1472 Otherwise if you plan to use vmlinux for capturing the crash dump
1473 change this value to start of the reserved region (Typically 16MB
1474 0x1000000). In other words, it can be set based on the "X" value as
1475 specified in the "crashkernel=YM@XM" command line boot parameter
1476 passed to the panic-ed kernel. Typically this parameter is set as
1477 crashkernel=64M@16M. Please take a look at
1478 Documentation/kdump/kdump.txt for more details about crash dumps.
1480 Usage of bzImage for capturing the crash dump is recommended as
1481 one does not have to build two kernels. Same kernel can be used
1482 as production kernel and capture kernel. Above option should have
1483 gone away after relocatable bzImage support is introduced. But it
1484 is present because there are users out there who continue to use
1485 vmlinux for dump capture. This option should go away down the
1488 Don't change this unless you know what you are doing.
1491 bool "Build a relocatable kernel (EXPERIMENTAL)"
1492 depends on EXPERIMENTAL
1494 This builds a kernel image that retains relocation information
1495 so it can be loaded someplace besides the default 1MB.
1496 The relocations tend to make the kernel binary about 10% larger,
1497 but are discarded at runtime.
1499 One use is for the kexec on panic case where the recovery kernel
1500 must live at a different physical address than the primary
1503 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1504 it has been loaded at and the compile time physical address
1505 (CONFIG_PHYSICAL_START) is ignored.
1507 config PHYSICAL_ALIGN
1509 prompt "Alignment value to which kernel should be aligned" if X86_32
1510 default "0x100000" if X86_32
1511 default "0x200000" if X86_64
1512 range 0x2000 0x400000
1514 This value puts the alignment restrictions on physical address
1515 where kernel is loaded and run from. Kernel is compiled for an
1516 address which meets above alignment restriction.
1518 If bootloader loads the kernel at a non-aligned address and
1519 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1520 address aligned to above value and run from there.
1522 If bootloader loads the kernel at a non-aligned address and
1523 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1524 load address and decompress itself to the address it has been
1525 compiled for and run from there. The address for which kernel is
1526 compiled already meets above alignment restrictions. Hence the
1527 end result is that kernel runs from a physical address meeting
1528 above alignment restrictions.
1530 Don't change this unless you know what you are doing.
1533 bool "Support for hot-pluggable CPUs"
1534 depends on SMP && HOTPLUG
1536 Say Y here to allow turning CPUs off and on. CPUs can be
1537 controlled through /sys/devices/system/cpu.
1538 ( Note: power management support will enable this option
1539 automatically on SMP systems. )
1540 Say N if you want to disable CPU hotplug.
1544 prompt "Compat VDSO support"
1545 depends on X86_32 || IA32_EMULATION
1547 Map the 32-bit VDSO to the predictable old-style address too.
1549 Say N here if you are running a sufficiently recent glibc
1550 version (2.3.3 or later), to remove the high-mapped
1551 VDSO mapping and to exclusively use the randomized VDSO.
1556 bool "Built-in kernel command line"
1559 Allow for specifying boot arguments to the kernel at
1560 build time. On some systems (e.g. embedded ones), it is
1561 necessary or convenient to provide some or all of the
1562 kernel boot arguments with the kernel itself (that is,
1563 to not rely on the boot loader to provide them.)
1565 To compile command line arguments into the kernel,
1566 set this option to 'Y', then fill in the
1567 the boot arguments in CONFIG_CMDLINE.
1569 Systems with fully functional boot loaders (i.e. non-embedded)
1570 should leave this option set to 'N'.
1573 string "Built-in kernel command string"
1574 depends on CMDLINE_BOOL
1577 Enter arguments here that should be compiled into the kernel
1578 image and used at boot time. If the boot loader provides a
1579 command line at boot time, it is appended to this string to
1580 form the full kernel command line, when the system boots.
1582 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1583 change this behavior.
1585 In most cases, the command line (whether built-in or provided
1586 by the boot loader) should specify the device for the root
1589 config CMDLINE_OVERRIDE
1590 bool "Built-in command line overrides boot loader arguments"
1592 depends on CMDLINE_BOOL
1594 Set this option to 'Y' to have the kernel ignore the boot loader
1595 command line, and use ONLY the built-in command line.
1597 This is used to work around broken boot loaders. This should
1598 be set to 'N' under normal conditions.
1602 config ARCH_ENABLE_MEMORY_HOTPLUG
1604 depends on X86_64 || (X86_32 && HIGHMEM)
1606 config ARCH_ENABLE_MEMORY_HOTREMOVE
1608 depends on MEMORY_HOTPLUG
1610 config HAVE_ARCH_EARLY_PFN_TO_NID
1614 menu "Power management and ACPI options"
1616 config ARCH_HIBERNATION_HEADER
1618 depends on X86_64 && HIBERNATION
1620 source "kernel/power/Kconfig"
1622 source "drivers/acpi/Kconfig"
1627 depends on APM || APM_MODULE
1630 tristate "APM (Advanced Power Management) BIOS support"
1631 depends on X86_32 && PM_SLEEP
1633 APM is a BIOS specification for saving power using several different
1634 techniques. This is mostly useful for battery powered laptops with
1635 APM compliant BIOSes. If you say Y here, the system time will be
1636 reset after a RESUME operation, the /proc/apm device will provide
1637 battery status information, and user-space programs will receive
1638 notification of APM "events" (e.g. battery status change).
1640 If you select "Y" here, you can disable actual use of the APM
1641 BIOS by passing the "apm=off" option to the kernel at boot time.
1643 Note that the APM support is almost completely disabled for
1644 machines with more than one CPU.
1646 In order to use APM, you will need supporting software. For location
1647 and more information, read <file:Documentation/power/pm.txt> and the
1648 Battery Powered Linux mini-HOWTO, available from
1649 <http://www.tldp.org/docs.html#howto>.
1651 This driver does not spin down disk drives (see the hdparm(8)
1652 manpage ("man 8 hdparm") for that), and it doesn't turn off
1653 VESA-compliant "green" monitors.
1655 This driver does not support the TI 4000M TravelMate and the ACER
1656 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1657 desktop machines also don't have compliant BIOSes, and this driver
1658 may cause those machines to panic during the boot phase.
1660 Generally, if you don't have a battery in your machine, there isn't
1661 much point in using this driver and you should say N. If you get
1662 random kernel OOPSes or reboots that don't seem to be related to
1663 anything, try disabling/enabling this option (or disabling/enabling
1666 Some other things you should try when experiencing seemingly random,
1669 1) make sure that you have enough swap space and that it is
1671 2) pass the "no-hlt" option to the kernel
1672 3) switch on floating point emulation in the kernel and pass
1673 the "no387" option to the kernel
1674 4) pass the "floppy=nodma" option to the kernel
1675 5) pass the "mem=4M" option to the kernel (thereby disabling
1676 all but the first 4 MB of RAM)
1677 6) make sure that the CPU is not over clocked.
1678 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1679 8) disable the cache from your BIOS settings
1680 9) install a fan for the video card or exchange video RAM
1681 10) install a better fan for the CPU
1682 11) exchange RAM chips
1683 12) exchange the motherboard.
1685 To compile this driver as a module, choose M here: the
1686 module will be called apm.
1690 config APM_IGNORE_USER_SUSPEND
1691 bool "Ignore USER SUSPEND"
1693 This option will ignore USER SUSPEND requests. On machines with a
1694 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1695 series notebooks, it is necessary to say Y because of a BIOS bug.
1697 config APM_DO_ENABLE
1698 bool "Enable PM at boot time"
1700 Enable APM features at boot time. From page 36 of the APM BIOS
1701 specification: "When disabled, the APM BIOS does not automatically
1702 power manage devices, enter the Standby State, enter the Suspend
1703 State, or take power saving steps in response to CPU Idle calls."
1704 This driver will make CPU Idle calls when Linux is idle (unless this
1705 feature is turned off -- see "Do CPU IDLE calls", below). This
1706 should always save battery power, but more complicated APM features
1707 will be dependent on your BIOS implementation. You may need to turn
1708 this option off if your computer hangs at boot time when using APM
1709 support, or if it beeps continuously instead of suspending. Turn
1710 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1711 T400CDT. This is off by default since most machines do fine without
1715 bool "Make CPU Idle calls when idle"
1717 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1718 On some machines, this can activate improved power savings, such as
1719 a slowed CPU clock rate, when the machine is idle. These idle calls
1720 are made after the idle loop has run for some length of time (e.g.,
1721 333 mS). On some machines, this will cause a hang at boot time or
1722 whenever the CPU becomes idle. (On machines with more than one CPU,
1723 this option does nothing.)
1725 config APM_DISPLAY_BLANK
1726 bool "Enable console blanking using APM"
1728 Enable console blanking using the APM. Some laptops can use this to
1729 turn off the LCD backlight when the screen blanker of the Linux
1730 virtual console blanks the screen. Note that this is only used by
1731 the virtual console screen blanker, and won't turn off the backlight
1732 when using the X Window system. This also doesn't have anything to
1733 do with your VESA-compliant power-saving monitor. Further, this
1734 option doesn't work for all laptops -- it might not turn off your
1735 backlight at all, or it might print a lot of errors to the console,
1736 especially if you are using gpm.
1738 config APM_ALLOW_INTS
1739 bool "Allow interrupts during APM BIOS calls"
1741 Normally we disable external interrupts while we are making calls to
1742 the APM BIOS as a measure to lessen the effects of a badly behaving
1743 BIOS implementation. The BIOS should reenable interrupts if it
1744 needs to. Unfortunately, some BIOSes do not -- especially those in
1745 many of the newer IBM Thinkpads. If you experience hangs when you
1746 suspend, try setting this to Y. Otherwise, say N.
1750 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1752 source "drivers/cpuidle/Kconfig"
1754 source "drivers/idle/Kconfig"
1759 menu "Bus options (PCI etc.)"
1764 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1766 Find out whether you have a PCI motherboard. PCI is the name of a
1767 bus system, i.e. the way the CPU talks to the other stuff inside
1768 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1769 VESA. If you have PCI, say Y, otherwise N.
1772 prompt "PCI access mode"
1773 depends on X86_32 && PCI
1776 On PCI systems, the BIOS can be used to detect the PCI devices and
1777 determine their configuration. However, some old PCI motherboards
1778 have BIOS bugs and may crash if this is done. Also, some embedded
1779 PCI-based systems don't have any BIOS at all. Linux can also try to
1780 detect the PCI hardware directly without using the BIOS.
1782 With this option, you can specify how Linux should detect the
1783 PCI devices. If you choose "BIOS", the BIOS will be used,
1784 if you choose "Direct", the BIOS won't be used, and if you
1785 choose "MMConfig", then PCI Express MMCONFIG will be used.
1786 If you choose "Any", the kernel will try MMCONFIG, then the
1787 direct access method and falls back to the BIOS if that doesn't
1788 work. If unsure, go with the default, which is "Any".
1793 config PCI_GOMMCONFIG
1810 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1812 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1815 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1819 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1823 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1830 bool "Support mmconfig PCI config space access"
1831 depends on X86_64 && PCI && ACPI
1834 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1835 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1837 DMA remapping (DMAR) devices support enables independent address
1838 translations for Direct Memory Access (DMA) from devices.
1839 These DMA remapping devices are reported via ACPI tables
1840 and include PCI device scope covered by these DMA
1843 config DMAR_DEFAULT_ON
1845 prompt "Enable DMA Remapping Devices by default"
1848 Selecting this option will enable a DMAR device at boot time if
1849 one is found. If this option is not selected, DMAR support can
1850 be enabled by passing intel_iommu=on to the kernel. It is
1851 recommended you say N here while the DMAR code remains
1856 prompt "Support for Graphics workaround"
1859 Current Graphics drivers tend to use physical address
1860 for DMA and avoid using DMA APIs. Setting this config
1861 option permits the IOMMU driver to set a unity map for
1862 all the OS-visible memory. Hence the driver can continue
1863 to use physical addresses for DMA.
1865 config DMAR_FLOPPY_WA
1869 Floppy disk drivers are know to bypass DMA API calls
1870 thereby failing to work when IOMMU is enabled. This
1871 workaround will setup a 1:1 mapping for the first
1872 16M to make floppy (an ISA device) work.
1875 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1876 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1879 Supports Interrupt remapping for IO-APIC and MSI devices.
1880 To use x2apic mode in the CPU's which support x2APIC enhancements or
1881 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1883 source "drivers/pci/pcie/Kconfig"
1885 source "drivers/pci/Kconfig"
1887 # x86_64 have no ISA slots, but do have ISA-style DMA.
1896 Find out whether you have ISA slots on your motherboard. ISA is the
1897 name of a bus system, i.e. the way the CPU talks to the other stuff
1898 inside your box. Other bus systems are PCI, EISA, MicroChannel
1899 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1900 newer boards don't support it. If you have ISA, say Y, otherwise N.
1906 The Extended Industry Standard Architecture (EISA) bus was
1907 developed as an open alternative to the IBM MicroChannel bus.
1909 The EISA bus provided some of the features of the IBM MicroChannel
1910 bus while maintaining backward compatibility with cards made for
1911 the older ISA bus. The EISA bus saw limited use between 1988 and
1912 1995 when it was made obsolete by the PCI bus.
1914 Say Y here if you are building a kernel for an EISA-based machine.
1918 source "drivers/eisa/Kconfig"
1923 MicroChannel Architecture is found in some IBM PS/2 machines and
1924 laptops. It is a bus system similar to PCI or ISA. See
1925 <file:Documentation/mca.txt> (and especially the web page given
1926 there) before attempting to build an MCA bus kernel.
1928 source "drivers/mca/Kconfig"
1931 tristate "NatSemi SCx200 support"
1933 This provides basic support for National Semiconductor's
1934 (now AMD's) Geode processors. The driver probes for the
1935 PCI-IDs of several on-chip devices, so its a good dependency
1936 for other scx200_* drivers.
1938 If compiled as a module, the driver is named scx200.
1940 config SCx200HR_TIMER
1941 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1942 depends on SCx200 && GENERIC_TIME
1945 This driver provides a clocksource built upon the on-chip
1946 27MHz high-resolution timer. Its also a workaround for
1947 NSC Geode SC-1100's buggy TSC, which loses time when the
1948 processor goes idle (as is done by the scheduler). The
1949 other workaround is idle=poll boot option.
1951 config GEODE_MFGPT_TIMER
1953 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1954 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1956 This driver provides a clock event source based on the MFGPT
1957 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1958 MFGPTs have a better resolution and max interval than the
1959 generic PIT, and are suitable for use as high-res timers.
1962 bool "One Laptop Per Child support"
1965 Add support for detecting the unique features of the OLPC
1972 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1974 source "drivers/pcmcia/Kconfig"
1976 source "drivers/pci/hotplug/Kconfig"
1981 menu "Executable file formats / Emulations"
1983 source "fs/Kconfig.binfmt"
1985 config IA32_EMULATION
1986 bool "IA32 Emulation"
1988 select COMPAT_BINFMT_ELF
1990 Include code to run 32-bit programs under a 64-bit kernel. You should
1991 likely turn this on, unless you're 100% sure that you don't have any
1992 32-bit programs left.
1995 tristate "IA32 a.out support"
1996 depends on IA32_EMULATION
1998 Support old a.out binaries in the 32bit emulation.
2002 depends on IA32_EMULATION
2004 config COMPAT_FOR_U64_ALIGNMENT
2008 config SYSVIPC_COMPAT
2010 depends on COMPAT && SYSVIPC
2015 config HAVE_ATOMIC_IOMAP
2019 source "net/Kconfig"
2021 source "drivers/Kconfig"
2023 source "drivers/firmware/Kconfig"
2027 source "arch/x86/Kconfig.debug"
2029 source "security/Kconfig"
2031 source "crypto/Kconfig"
2033 source "arch/x86/kvm/Kconfig"
2035 source "lib/Kconfig"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blob