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_NONFATAL
787 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
788 depends on X86_32 && X86_MCE
790 Enabling this feature starts a timer that triggers every 5 seconds which
791 will look at the machine check registers to see if anything happened.
792 Non-fatal problems automatically get corrected (but still logged).
793 Disable this if you don't want to see these messages.
794 Seeing the messages this option prints out may be indicative of dying
795 or out-of-spec (ie, overclocked) hardware.
796 This option only does something on certain CPUs.
797 (AMD Athlon/Duron and Intel Pentium 4)
799 config X86_MCE_P4THERMAL
800 bool "check for P4 thermal throttling interrupt."
801 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
803 Enabling this feature will cause a message to be printed when the P4
804 enters thermal throttling.
807 bool "Enable VM86 support" if EMBEDDED
811 This option is required by programs like DOSEMU to run 16-bit legacy
812 code on X86 processors. It also may be needed by software like
813 XFree86 to initialize some video cards via BIOS. Disabling this
814 option saves about 6k.
817 tristate "Toshiba Laptop support"
820 This adds a driver to safely access the System Management Mode of
821 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
822 not work on models with a Phoenix BIOS. The System Management Mode
823 is used to set the BIOS and power saving options on Toshiba portables.
825 For information on utilities to make use of this driver see the
826 Toshiba Linux utilities web site at:
827 <http://www.buzzard.org.uk/toshiba/>.
829 Say Y if you intend to run this kernel on a Toshiba portable.
833 tristate "Dell laptop support"
835 This adds a driver to safely access the System Management Mode
836 of the CPU on the Dell Inspiron 8000. The System Management Mode
837 is used to read cpu temperature and cooling fan status and to
838 control the fans on the I8K portables.
840 This driver has been tested only on the Inspiron 8000 but it may
841 also work with other Dell laptops. You can force loading on other
842 models by passing the parameter `force=1' to the module. Use at
845 For information on utilities to make use of this driver see the
846 I8K Linux utilities web site at:
847 <http://people.debian.org/~dz/i8k/>
849 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
852 config X86_REBOOTFIXUPS
853 bool "Enable X86 board specific fixups for reboot"
856 This enables chipset and/or board specific fixups to be done
857 in order to get reboot to work correctly. This is only needed on
858 some combinations of hardware and BIOS. The symptom, for which
859 this config is intended, is when reboot ends with a stalled/hung
862 Currently, the only fixup is for the Geode machines using
863 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
865 Say Y if you want to enable the fixup. Currently, it's safe to
866 enable this option even if you don't need it.
870 tristate "/dev/cpu/microcode - microcode support"
873 If you say Y here, you will be able to update the microcode on
874 certain Intel and AMD processors. The Intel support is for the
875 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
876 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
877 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
878 You will obviously need the actual microcode binary data itself
879 which is not shipped with the Linux kernel.
881 This option selects the general module only, you need to select
882 at least one vendor specific module as well.
884 To compile this driver as a module, choose M here: the
885 module will be called microcode.
887 config MICROCODE_INTEL
888 bool "Intel microcode patch loading support"
893 This options enables microcode patch loading support for Intel
896 For latest news and information on obtaining all the required
897 Intel ingredients for this driver, check:
898 <http://www.urbanmyth.org/microcode/>.
901 bool "AMD microcode patch loading support"
905 If you select this option, microcode patch loading support for AMD
906 processors will be enabled.
908 config MICROCODE_OLD_INTERFACE
913 tristate "/dev/cpu/*/msr - Model-specific register support"
915 This device gives privileged processes access to the x86
916 Model-Specific Registers (MSRs). It is a character device with
917 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
918 MSR accesses are directed to a specific CPU on multi-processor
922 tristate "/dev/cpu/*/cpuid - CPU information support"
924 This device gives processes access to the x86 CPUID instruction to
925 be executed on a specific processor. It is a character device
926 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
930 prompt "High Memory Support"
931 default HIGHMEM4G if !X86_NUMAQ
932 default HIGHMEM64G if X86_NUMAQ
937 depends on !X86_NUMAQ
939 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
940 However, the address space of 32-bit x86 processors is only 4
941 Gigabytes large. That means that, if you have a large amount of
942 physical memory, not all of it can be "permanently mapped" by the
943 kernel. The physical memory that's not permanently mapped is called
946 If you are compiling a kernel which will never run on a machine with
947 more than 1 Gigabyte total physical RAM, answer "off" here (default
948 choice and suitable for most users). This will result in a "3GB/1GB"
949 split: 3GB are mapped so that each process sees a 3GB virtual memory
950 space and the remaining part of the 4GB virtual memory space is used
951 by the kernel to permanently map as much physical memory as
954 If the machine has between 1 and 4 Gigabytes physical RAM, then
957 If more than 4 Gigabytes is used then answer "64GB" here. This
958 selection turns Intel PAE (Physical Address Extension) mode on.
959 PAE implements 3-level paging on IA32 processors. PAE is fully
960 supported by Linux, PAE mode is implemented on all recent Intel
961 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
962 then the kernel will not boot on CPUs that don't support PAE!
964 The actual amount of total physical memory will either be
965 auto detected or can be forced by using a kernel command line option
966 such as "mem=256M". (Try "man bootparam" or see the documentation of
967 your boot loader (lilo or loadlin) about how to pass options to the
968 kernel at boot time.)
970 If unsure, say "off".
974 depends on !X86_NUMAQ
976 Select this if you have a 32-bit processor and between 1 and 4
977 gigabytes of physical RAM.
981 depends on !M386 && !M486
984 Select this if you have a 32-bit processor and more than 4
985 gigabytes of physical RAM.
990 depends on EXPERIMENTAL
991 prompt "Memory split" if EMBEDDED
995 Select the desired split between kernel and user memory.
997 If the address range available to the kernel is less than the
998 physical memory installed, the remaining memory will be available
999 as "high memory". Accessing high memory is a little more costly
1000 than low memory, as it needs to be mapped into the kernel first.
1001 Note that increasing the kernel address space limits the range
1002 available to user programs, making the address space there
1003 tighter. Selecting anything other than the default 3G/1G split
1004 will also likely make your kernel incompatible with binary-only
1007 If you are not absolutely sure what you are doing, leave this
1011 bool "3G/1G user/kernel split"
1012 config VMSPLIT_3G_OPT
1014 bool "3G/1G user/kernel split (for full 1G low memory)"
1016 bool "2G/2G user/kernel split"
1017 config VMSPLIT_2G_OPT
1019 bool "2G/2G user/kernel split (for full 2G low memory)"
1021 bool "1G/3G user/kernel split"
1026 default 0xB0000000 if VMSPLIT_3G_OPT
1027 default 0x80000000 if VMSPLIT_2G
1028 default 0x78000000 if VMSPLIT_2G_OPT
1029 default 0x40000000 if VMSPLIT_1G
1035 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1038 bool "PAE (Physical Address Extension) Support"
1039 depends on X86_32 && !HIGHMEM4G
1041 PAE is required for NX support, and furthermore enables
1042 larger swapspace support for non-overcommit purposes. It
1043 has the cost of more pagetable lookup overhead, and also
1044 consumes more pagetable space per process.
1046 config ARCH_PHYS_ADDR_T_64BIT
1047 def_bool X86_64 || X86_PAE
1049 config DIRECT_GBPAGES
1050 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1054 Allow the kernel linear mapping to use 1GB pages on CPUs that
1055 support it. This can improve the kernel's performance a tiny bit by
1056 reducing TLB pressure. If in doubt, say "Y".
1058 # Common NUMA Features
1060 bool "Numa Memory Allocation and Scheduler Support"
1062 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1063 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1065 Enable NUMA (Non Uniform Memory Access) support.
1067 The kernel will try to allocate memory used by a CPU on the
1068 local memory controller of the CPU and add some more
1069 NUMA awareness to the kernel.
1071 For 64-bit this is recommended if the system is Intel Core i7
1072 (or later), AMD Opteron, or EM64T NUMA.
1074 For 32-bit this is only needed on (rare) 32-bit-only platforms
1075 that support NUMA topologies, such as NUMAQ / Summit, or if you
1076 boot a 32-bit kernel on a 64-bit NUMA platform.
1078 Otherwise, you should say N.
1080 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1081 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1085 prompt "Old style AMD Opteron NUMA detection"
1086 depends on X86_64 && NUMA && PCI
1088 Enable K8 NUMA node topology detection. You should say Y here if
1089 you have a multi processor AMD K8 system. This uses an old
1090 method to read the NUMA configuration directly from the builtin
1091 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1092 instead, which also takes priority if both are compiled in.
1094 config X86_64_ACPI_NUMA
1096 prompt "ACPI NUMA detection"
1097 depends on X86_64 && NUMA && ACPI && PCI
1100 Enable ACPI SRAT based node topology detection.
1102 # Some NUMA nodes have memory ranges that span
1103 # other nodes. Even though a pfn is valid and
1104 # between a node's start and end pfns, it may not
1105 # reside on that node. See memmap_init_zone()
1107 config NODES_SPAN_OTHER_NODES
1109 depends on X86_64_ACPI_NUMA
1112 bool "NUMA emulation"
1113 depends on X86_64 && NUMA
1115 Enable NUMA emulation. A flat machine will be split
1116 into virtual nodes when booted with "numa=fake=N", where N is the
1117 number of nodes. This is only useful for debugging.
1120 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1122 default "9" if MAXSMP
1123 default "6" if X86_64
1124 default "4" if X86_NUMAQ
1126 depends on NEED_MULTIPLE_NODES
1128 Specify the maximum number of NUMA Nodes available on the target
1129 system. Increases memory reserved to accomodate various tables.
1131 config HAVE_ARCH_BOOTMEM
1133 depends on X86_32 && NUMA
1135 config ARCH_HAVE_MEMORY_PRESENT
1137 depends on X86_32 && DISCONTIGMEM
1139 config NEED_NODE_MEMMAP_SIZE
1141 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1143 config HAVE_ARCH_ALLOC_REMAP
1145 depends on X86_32 && NUMA
1147 config ARCH_FLATMEM_ENABLE
1149 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1151 config ARCH_DISCONTIGMEM_ENABLE
1153 depends on NUMA && X86_32
1155 config ARCH_DISCONTIGMEM_DEFAULT
1157 depends on NUMA && X86_32
1159 config ARCH_SPARSEMEM_DEFAULT
1163 config ARCH_SPARSEMEM_ENABLE
1165 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1166 select SPARSEMEM_STATIC if X86_32
1167 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1169 config ARCH_SELECT_MEMORY_MODEL
1171 depends on ARCH_SPARSEMEM_ENABLE
1173 config ARCH_MEMORY_PROBE
1175 depends on MEMORY_HOTPLUG
1180 bool "Allocate 3rd-level pagetables from highmem"
1181 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1183 The VM uses one page table entry for each page of physical memory.
1184 For systems with a lot of RAM, this can be wasteful of precious
1185 low memory. Setting this option will put user-space page table
1186 entries in high memory.
1188 config X86_CHECK_BIOS_CORRUPTION
1189 bool "Check for low memory corruption"
1191 Periodically check for memory corruption in low memory, which
1192 is suspected to be caused by BIOS. Even when enabled in the
1193 configuration, it is disabled at runtime. Enable it by
1194 setting "memory_corruption_check=1" on the kernel command
1195 line. By default it scans the low 64k of memory every 60
1196 seconds; see the memory_corruption_check_size and
1197 memory_corruption_check_period parameters in
1198 Documentation/kernel-parameters.txt to adjust this.
1200 When enabled with the default parameters, this option has
1201 almost no overhead, as it reserves a relatively small amount
1202 of memory and scans it infrequently. It both detects corruption
1203 and prevents it from affecting the running system.
1205 It is, however, intended as a diagnostic tool; if repeatable
1206 BIOS-originated corruption always affects the same memory,
1207 you can use memmap= to prevent the kernel from using that
1210 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1211 bool "Set the default setting of memory_corruption_check"
1212 depends on X86_CHECK_BIOS_CORRUPTION
1215 Set whether the default state of memory_corruption_check is
1218 config X86_RESERVE_LOW_64K
1219 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1222 Reserve the first 64K of physical RAM on BIOSes that are known
1223 to potentially corrupt that memory range. A numbers of BIOSes are
1224 known to utilize this area during suspend/resume, so it must not
1225 be used by the kernel.
1227 Set this to N if you are absolutely sure that you trust the BIOS
1228 to get all its memory reservations and usages right.
1230 If you have doubts about the BIOS (e.g. suspend/resume does not
1231 work or there's kernel crashes after certain hardware hotplug
1232 events) and it's not AMI or Phoenix, then you might want to enable
1233 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1234 corruption patterns.
1238 config MATH_EMULATION
1240 prompt "Math emulation" if X86_32
1242 Linux can emulate a math coprocessor (used for floating point
1243 operations) if you don't have one. 486DX and Pentium processors have
1244 a math coprocessor built in, 486SX and 386 do not, unless you added
1245 a 487DX or 387, respectively. (The messages during boot time can
1246 give you some hints here ["man dmesg"].) Everyone needs either a
1247 coprocessor or this emulation.
1249 If you don't have a math coprocessor, you need to say Y here; if you
1250 say Y here even though you have a coprocessor, the coprocessor will
1251 be used nevertheless. (This behavior can be changed with the kernel
1252 command line option "no387", which comes handy if your coprocessor
1253 is broken. Try "man bootparam" or see the documentation of your boot
1254 loader (lilo or loadlin) about how to pass options to the kernel at
1255 boot time.) This means that it is a good idea to say Y here if you
1256 intend to use this kernel on different machines.
1258 More information about the internals of the Linux math coprocessor
1259 emulation can be found in <file:arch/x86/math-emu/README>.
1261 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1262 kernel, it won't hurt.
1265 bool "MTRR (Memory Type Range Register) support"
1267 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1268 the Memory Type Range Registers (MTRRs) may be used to control
1269 processor access to memory ranges. This is most useful if you have
1270 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1271 allows bus write transfers to be combined into a larger transfer
1272 before bursting over the PCI/AGP bus. This can increase performance
1273 of image write operations 2.5 times or more. Saying Y here creates a
1274 /proc/mtrr file which may be used to manipulate your processor's
1275 MTRRs. Typically the X server should use this.
1277 This code has a reasonably generic interface so that similar
1278 control registers on other processors can be easily supported
1281 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1282 Registers (ARRs) which provide a similar functionality to MTRRs. For
1283 these, the ARRs are used to emulate the MTRRs.
1284 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1285 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1286 write-combining. All of these processors are supported by this code
1287 and it makes sense to say Y here if you have one of them.
1289 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1290 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1291 can lead to all sorts of problems, so it's good to say Y here.
1293 You can safely say Y even if your machine doesn't have MTRRs, you'll
1294 just add about 9 KB to your kernel.
1296 See <file:Documentation/x86/mtrr.txt> for more information.
1298 config MTRR_SANITIZER
1300 prompt "MTRR cleanup support"
1303 Convert MTRR layout from continuous to discrete, so X drivers can
1304 add writeback entries.
1306 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1307 The largest mtrr entry size for a continous block can be set with
1312 config MTRR_SANITIZER_ENABLE_DEFAULT
1313 int "MTRR cleanup enable value (0-1)"
1316 depends on MTRR_SANITIZER
1318 Enable mtrr cleanup default value
1320 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1321 int "MTRR cleanup spare reg num (0-7)"
1324 depends on MTRR_SANITIZER
1326 mtrr cleanup spare entries default, it can be changed via
1327 mtrr_spare_reg_nr=N on the kernel command line.
1331 prompt "x86 PAT support"
1334 Use PAT attributes to setup page level cache control.
1336 PATs are the modern equivalents of MTRRs and are much more
1337 flexible than MTRRs.
1339 Say N here if you see bootup problems (boot crash, boot hang,
1340 spontaneous reboots) or a non-working video driver.
1345 bool "EFI runtime service support"
1348 This enables the kernel to use EFI runtime services that are
1349 available (such as the EFI variable services).
1351 This option is only useful on systems that have EFI firmware.
1352 In addition, you should use the latest ELILO loader available
1353 at <http://elilo.sourceforge.net> in order to take advantage
1354 of EFI runtime services. However, even with this option, the
1355 resultant kernel should continue to boot on existing non-EFI
1360 prompt "Enable seccomp to safely compute untrusted bytecode"
1362 This kernel feature is useful for number crunching applications
1363 that may need to compute untrusted bytecode during their
1364 execution. By using pipes or other transports made available to
1365 the process as file descriptors supporting the read/write
1366 syscalls, it's possible to isolate those applications in
1367 their own address space using seccomp. Once seccomp is
1368 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1369 and the task is only allowed to execute a few safe syscalls
1370 defined by each seccomp mode.
1372 If unsure, say Y. Only embedded should say N here.
1374 config CC_STACKPROTECTOR_ALL
1377 config CC_STACKPROTECTOR
1378 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1379 select CC_STACKPROTECTOR_ALL
1381 This option turns on the -fstack-protector GCC feature. This
1382 feature puts, at the beginning of functions, a canary value on
1383 the stack just before the return address, and validates
1384 the value just before actually returning. Stack based buffer
1385 overflows (that need to overwrite this return address) now also
1386 overwrite the canary, which gets detected and the attack is then
1387 neutralized via a kernel panic.
1389 This feature requires gcc version 4.2 or above, or a distribution
1390 gcc with the feature backported. Older versions are automatically
1391 detected and for those versions, this configuration option is
1392 ignored. (and a warning is printed during bootup)
1394 source kernel/Kconfig.hz
1397 bool "kexec system call"
1399 kexec is a system call that implements the ability to shutdown your
1400 current kernel, and to start another kernel. It is like a reboot
1401 but it is independent of the system firmware. And like a reboot
1402 you can start any kernel with it, not just Linux.
1404 The name comes from the similarity to the exec system call.
1406 It is an ongoing process to be certain the hardware in a machine
1407 is properly shutdown, so do not be surprised if this code does not
1408 initially work for you. It may help to enable device hotplugging
1409 support. As of this writing the exact hardware interface is
1410 strongly in flux, so no good recommendation can be made.
1413 bool "kernel crash dumps"
1414 depends on X86_64 || (X86_32 && HIGHMEM)
1416 Generate crash dump after being started by kexec.
1417 This should be normally only set in special crash dump kernels
1418 which are loaded in the main kernel with kexec-tools into
1419 a specially reserved region and then later executed after
1420 a crash by kdump/kexec. The crash dump kernel must be compiled
1421 to a memory address not used by the main kernel or BIOS using
1422 PHYSICAL_START, or it must be built as a relocatable image
1423 (CONFIG_RELOCATABLE=y).
1424 For more details see Documentation/kdump/kdump.txt
1427 bool "kexec jump (EXPERIMENTAL)"
1428 depends on EXPERIMENTAL
1429 depends on KEXEC && HIBERNATION && X86_32
1431 Jump between original kernel and kexeced kernel and invoke
1432 code in physical address mode via KEXEC
1434 config PHYSICAL_START
1435 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1436 default "0x1000000" if X86_NUMAQ
1437 default "0x200000" if X86_64
1440 This gives the physical address where the kernel is loaded.
1442 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1443 bzImage will decompress itself to above physical address and
1444 run from there. Otherwise, bzImage will run from the address where
1445 it has been loaded by the boot loader and will ignore above physical
1448 In normal kdump cases one does not have to set/change this option
1449 as now bzImage can be compiled as a completely relocatable image
1450 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1451 address. This option is mainly useful for the folks who don't want
1452 to use a bzImage for capturing the crash dump and want to use a
1453 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1454 to be specifically compiled to run from a specific memory area
1455 (normally a reserved region) and this option comes handy.
1457 So if you are using bzImage for capturing the crash dump, leave
1458 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1459 Otherwise if you plan to use vmlinux for capturing the crash dump
1460 change this value to start of the reserved region (Typically 16MB
1461 0x1000000). In other words, it can be set based on the "X" value as
1462 specified in the "crashkernel=YM@XM" command line boot parameter
1463 passed to the panic-ed kernel. Typically this parameter is set as
1464 crashkernel=64M@16M. Please take a look at
1465 Documentation/kdump/kdump.txt for more details about crash dumps.
1467 Usage of bzImage for capturing the crash dump is recommended as
1468 one does not have to build two kernels. Same kernel can be used
1469 as production kernel and capture kernel. Above option should have
1470 gone away after relocatable bzImage support is introduced. But it
1471 is present because there are users out there who continue to use
1472 vmlinux for dump capture. This option should go away down the
1475 Don't change this unless you know what you are doing.
1478 bool "Build a relocatable kernel (EXPERIMENTAL)"
1479 depends on EXPERIMENTAL
1481 This builds a kernel image that retains relocation information
1482 so it can be loaded someplace besides the default 1MB.
1483 The relocations tend to make the kernel binary about 10% larger,
1484 but are discarded at runtime.
1486 One use is for the kexec on panic case where the recovery kernel
1487 must live at a different physical address than the primary
1490 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1491 it has been loaded at and the compile time physical address
1492 (CONFIG_PHYSICAL_START) is ignored.
1494 config PHYSICAL_ALIGN
1496 prompt "Alignment value to which kernel should be aligned" if X86_32
1497 default "0x100000" if X86_32
1498 default "0x200000" if X86_64
1499 range 0x2000 0x400000
1501 This value puts the alignment restrictions on physical address
1502 where kernel is loaded and run from. Kernel is compiled for an
1503 address which meets above alignment restriction.
1505 If bootloader loads the kernel at a non-aligned address and
1506 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1507 address aligned to above value and run from there.
1509 If bootloader loads the kernel at a non-aligned address and
1510 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1511 load address and decompress itself to the address it has been
1512 compiled for and run from there. The address for which kernel is
1513 compiled already meets above alignment restrictions. Hence the
1514 end result is that kernel runs from a physical address meeting
1515 above alignment restrictions.
1517 Don't change this unless you know what you are doing.
1520 bool "Support for hot-pluggable CPUs"
1521 depends on SMP && HOTPLUG
1523 Say Y here to allow turning CPUs off and on. CPUs can be
1524 controlled through /sys/devices/system/cpu.
1525 ( Note: power management support will enable this option
1526 automatically on SMP systems. )
1527 Say N if you want to disable CPU hotplug.
1531 prompt "Compat VDSO support"
1532 depends on X86_32 || IA32_EMULATION
1534 Map the 32-bit VDSO to the predictable old-style address too.
1536 Say N here if you are running a sufficiently recent glibc
1537 version (2.3.3 or later), to remove the high-mapped
1538 VDSO mapping and to exclusively use the randomized VDSO.
1543 bool "Built-in kernel command line"
1546 Allow for specifying boot arguments to the kernel at
1547 build time. On some systems (e.g. embedded ones), it is
1548 necessary or convenient to provide some or all of the
1549 kernel boot arguments with the kernel itself (that is,
1550 to not rely on the boot loader to provide them.)
1552 To compile command line arguments into the kernel,
1553 set this option to 'Y', then fill in the
1554 the boot arguments in CONFIG_CMDLINE.
1556 Systems with fully functional boot loaders (i.e. non-embedded)
1557 should leave this option set to 'N'.
1560 string "Built-in kernel command string"
1561 depends on CMDLINE_BOOL
1564 Enter arguments here that should be compiled into the kernel
1565 image and used at boot time. If the boot loader provides a
1566 command line at boot time, it is appended to this string to
1567 form the full kernel command line, when the system boots.
1569 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1570 change this behavior.
1572 In most cases, the command line (whether built-in or provided
1573 by the boot loader) should specify the device for the root
1576 config CMDLINE_OVERRIDE
1577 bool "Built-in command line overrides boot loader arguments"
1579 depends on CMDLINE_BOOL
1581 Set this option to 'Y' to have the kernel ignore the boot loader
1582 command line, and use ONLY the built-in command line.
1584 This is used to work around broken boot loaders. This should
1585 be set to 'N' under normal conditions.
1589 config ARCH_ENABLE_MEMORY_HOTPLUG
1591 depends on X86_64 || (X86_32 && HIGHMEM)
1593 config ARCH_ENABLE_MEMORY_HOTREMOVE
1595 depends on MEMORY_HOTPLUG
1597 config HAVE_ARCH_EARLY_PFN_TO_NID
1601 menu "Power management and ACPI options"
1603 config ARCH_HIBERNATION_HEADER
1605 depends on X86_64 && HIBERNATION
1607 source "kernel/power/Kconfig"
1609 source "drivers/acpi/Kconfig"
1614 depends on APM || APM_MODULE
1617 tristate "APM (Advanced Power Management) BIOS support"
1618 depends on X86_32 && PM_SLEEP
1620 APM is a BIOS specification for saving power using several different
1621 techniques. This is mostly useful for battery powered laptops with
1622 APM compliant BIOSes. If you say Y here, the system time will be
1623 reset after a RESUME operation, the /proc/apm device will provide
1624 battery status information, and user-space programs will receive
1625 notification of APM "events" (e.g. battery status change).
1627 If you select "Y" here, you can disable actual use of the APM
1628 BIOS by passing the "apm=off" option to the kernel at boot time.
1630 Note that the APM support is almost completely disabled for
1631 machines with more than one CPU.
1633 In order to use APM, you will need supporting software. For location
1634 and more information, read <file:Documentation/power/pm.txt> and the
1635 Battery Powered Linux mini-HOWTO, available from
1636 <http://www.tldp.org/docs.html#howto>.
1638 This driver does not spin down disk drives (see the hdparm(8)
1639 manpage ("man 8 hdparm") for that), and it doesn't turn off
1640 VESA-compliant "green" monitors.
1642 This driver does not support the TI 4000M TravelMate and the ACER
1643 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1644 desktop machines also don't have compliant BIOSes, and this driver
1645 may cause those machines to panic during the boot phase.
1647 Generally, if you don't have a battery in your machine, there isn't
1648 much point in using this driver and you should say N. If you get
1649 random kernel OOPSes or reboots that don't seem to be related to
1650 anything, try disabling/enabling this option (or disabling/enabling
1653 Some other things you should try when experiencing seemingly random,
1656 1) make sure that you have enough swap space and that it is
1658 2) pass the "no-hlt" option to the kernel
1659 3) switch on floating point emulation in the kernel and pass
1660 the "no387" option to the kernel
1661 4) pass the "floppy=nodma" option to the kernel
1662 5) pass the "mem=4M" option to the kernel (thereby disabling
1663 all but the first 4 MB of RAM)
1664 6) make sure that the CPU is not over clocked.
1665 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1666 8) disable the cache from your BIOS settings
1667 9) install a fan for the video card or exchange video RAM
1668 10) install a better fan for the CPU
1669 11) exchange RAM chips
1670 12) exchange the motherboard.
1672 To compile this driver as a module, choose M here: the
1673 module will be called apm.
1677 config APM_IGNORE_USER_SUSPEND
1678 bool "Ignore USER SUSPEND"
1680 This option will ignore USER SUSPEND requests. On machines with a
1681 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1682 series notebooks, it is necessary to say Y because of a BIOS bug.
1684 config APM_DO_ENABLE
1685 bool "Enable PM at boot time"
1687 Enable APM features at boot time. From page 36 of the APM BIOS
1688 specification: "When disabled, the APM BIOS does not automatically
1689 power manage devices, enter the Standby State, enter the Suspend
1690 State, or take power saving steps in response to CPU Idle calls."
1691 This driver will make CPU Idle calls when Linux is idle (unless this
1692 feature is turned off -- see "Do CPU IDLE calls", below). This
1693 should always save battery power, but more complicated APM features
1694 will be dependent on your BIOS implementation. You may need to turn
1695 this option off if your computer hangs at boot time when using APM
1696 support, or if it beeps continuously instead of suspending. Turn
1697 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1698 T400CDT. This is off by default since most machines do fine without
1702 bool "Make CPU Idle calls when idle"
1704 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1705 On some machines, this can activate improved power savings, such as
1706 a slowed CPU clock rate, when the machine is idle. These idle calls
1707 are made after the idle loop has run for some length of time (e.g.,
1708 333 mS). On some machines, this will cause a hang at boot time or
1709 whenever the CPU becomes idle. (On machines with more than one CPU,
1710 this option does nothing.)
1712 config APM_DISPLAY_BLANK
1713 bool "Enable console blanking using APM"
1715 Enable console blanking using the APM. Some laptops can use this to
1716 turn off the LCD backlight when the screen blanker of the Linux
1717 virtual console blanks the screen. Note that this is only used by
1718 the virtual console screen blanker, and won't turn off the backlight
1719 when using the X Window system. This also doesn't have anything to
1720 do with your VESA-compliant power-saving monitor. Further, this
1721 option doesn't work for all laptops -- it might not turn off your
1722 backlight at all, or it might print a lot of errors to the console,
1723 especially if you are using gpm.
1725 config APM_ALLOW_INTS
1726 bool "Allow interrupts during APM BIOS calls"
1728 Normally we disable external interrupts while we are making calls to
1729 the APM BIOS as a measure to lessen the effects of a badly behaving
1730 BIOS implementation. The BIOS should reenable interrupts if it
1731 needs to. Unfortunately, some BIOSes do not -- especially those in
1732 many of the newer IBM Thinkpads. If you experience hangs when you
1733 suspend, try setting this to Y. Otherwise, say N.
1737 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1739 source "drivers/cpuidle/Kconfig"
1741 source "drivers/idle/Kconfig"
1746 menu "Bus options (PCI etc.)"
1751 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1753 Find out whether you have a PCI motherboard. PCI is the name of a
1754 bus system, i.e. the way the CPU talks to the other stuff inside
1755 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1756 VESA. If you have PCI, say Y, otherwise N.
1759 prompt "PCI access mode"
1760 depends on X86_32 && PCI
1763 On PCI systems, the BIOS can be used to detect the PCI devices and
1764 determine their configuration. However, some old PCI motherboards
1765 have BIOS bugs and may crash if this is done. Also, some embedded
1766 PCI-based systems don't have any BIOS at all. Linux can also try to
1767 detect the PCI hardware directly without using the BIOS.
1769 With this option, you can specify how Linux should detect the
1770 PCI devices. If you choose "BIOS", the BIOS will be used,
1771 if you choose "Direct", the BIOS won't be used, and if you
1772 choose "MMConfig", then PCI Express MMCONFIG will be used.
1773 If you choose "Any", the kernel will try MMCONFIG, then the
1774 direct access method and falls back to the BIOS if that doesn't
1775 work. If unsure, go with the default, which is "Any".
1780 config PCI_GOMMCONFIG
1797 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1799 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1802 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1806 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1810 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1817 bool "Support mmconfig PCI config space access"
1818 depends on X86_64 && PCI && ACPI
1821 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1822 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1824 DMA remapping (DMAR) devices support enables independent address
1825 translations for Direct Memory Access (DMA) from devices.
1826 These DMA remapping devices are reported via ACPI tables
1827 and include PCI device scope covered by these DMA
1830 config DMAR_DEFAULT_ON
1832 prompt "Enable DMA Remapping Devices by default"
1835 Selecting this option will enable a DMAR device at boot time if
1836 one is found. If this option is not selected, DMAR support can
1837 be enabled by passing intel_iommu=on to the kernel. It is
1838 recommended you say N here while the DMAR code remains
1843 prompt "Support for Graphics workaround"
1846 Current Graphics drivers tend to use physical address
1847 for DMA and avoid using DMA APIs. Setting this config
1848 option permits the IOMMU driver to set a unity map for
1849 all the OS-visible memory. Hence the driver can continue
1850 to use physical addresses for DMA.
1852 config DMAR_FLOPPY_WA
1856 Floppy disk drivers are know to bypass DMA API calls
1857 thereby failing to work when IOMMU is enabled. This
1858 workaround will setup a 1:1 mapping for the first
1859 16M to make floppy (an ISA device) work.
1862 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1863 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1866 Supports Interrupt remapping for IO-APIC and MSI devices.
1867 To use x2apic mode in the CPU's which support x2APIC enhancements or
1868 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1870 source "drivers/pci/pcie/Kconfig"
1872 source "drivers/pci/Kconfig"
1874 # x86_64 have no ISA slots, but do have ISA-style DMA.
1883 Find out whether you have ISA slots on your motherboard. ISA is the
1884 name of a bus system, i.e. the way the CPU talks to the other stuff
1885 inside your box. Other bus systems are PCI, EISA, MicroChannel
1886 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1887 newer boards don't support it. If you have ISA, say Y, otherwise N.
1893 The Extended Industry Standard Architecture (EISA) bus was
1894 developed as an open alternative to the IBM MicroChannel bus.
1896 The EISA bus provided some of the features of the IBM MicroChannel
1897 bus while maintaining backward compatibility with cards made for
1898 the older ISA bus. The EISA bus saw limited use between 1988 and
1899 1995 when it was made obsolete by the PCI bus.
1901 Say Y here if you are building a kernel for an EISA-based machine.
1905 source "drivers/eisa/Kconfig"
1910 MicroChannel Architecture is found in some IBM PS/2 machines and
1911 laptops. It is a bus system similar to PCI or ISA. See
1912 <file:Documentation/mca.txt> (and especially the web page given
1913 there) before attempting to build an MCA bus kernel.
1915 source "drivers/mca/Kconfig"
1918 tristate "NatSemi SCx200 support"
1920 This provides basic support for National Semiconductor's
1921 (now AMD's) Geode processors. The driver probes for the
1922 PCI-IDs of several on-chip devices, so its a good dependency
1923 for other scx200_* drivers.
1925 If compiled as a module, the driver is named scx200.
1927 config SCx200HR_TIMER
1928 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1929 depends on SCx200 && GENERIC_TIME
1932 This driver provides a clocksource built upon the on-chip
1933 27MHz high-resolution timer. Its also a workaround for
1934 NSC Geode SC-1100's buggy TSC, which loses time when the
1935 processor goes idle (as is done by the scheduler). The
1936 other workaround is idle=poll boot option.
1938 config GEODE_MFGPT_TIMER
1940 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1941 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1943 This driver provides a clock event source based on the MFGPT
1944 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1945 MFGPTs have a better resolution and max interval than the
1946 generic PIT, and are suitable for use as high-res timers.
1949 bool "One Laptop Per Child support"
1952 Add support for detecting the unique features of the OLPC
1959 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1961 source "drivers/pcmcia/Kconfig"
1963 source "drivers/pci/hotplug/Kconfig"
1968 menu "Executable file formats / Emulations"
1970 source "fs/Kconfig.binfmt"
1972 config IA32_EMULATION
1973 bool "IA32 Emulation"
1975 select COMPAT_BINFMT_ELF
1977 Include code to run 32-bit programs under a 64-bit kernel. You should
1978 likely turn this on, unless you're 100% sure that you don't have any
1979 32-bit programs left.
1982 tristate "IA32 a.out support"
1983 depends on IA32_EMULATION
1985 Support old a.out binaries in the 32bit emulation.
1989 depends on IA32_EMULATION
1991 config COMPAT_FOR_U64_ALIGNMENT
1995 config SYSVIPC_COMPAT
1997 depends on COMPAT && SYSVIPC
2002 config HAVE_ATOMIC_IOMAP
2006 source "net/Kconfig"
2008 source "drivers/Kconfig"
2010 source "drivers/firmware/Kconfig"
2014 source "arch/x86/Kconfig.debug"
2016 source "security/Kconfig"
2018 source "crypto/Kconfig"
2020 source "arch/x86/kvm/Kconfig"
2022 source "lib/Kconfig"