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_DMA_API_DEBUG
46 select HAVE_KERNEL_GZIP
47 select HAVE_KERNEL_BZIP2
48 select HAVE_KERNEL_LZMA
52 default "arch/x86/configs/i386_defconfig" if X86_32
53 default "arch/x86/configs/x86_64_defconfig" if X86_64
58 config GENERIC_CMOS_UPDATE
61 config CLOCKSOURCE_WATCHDOG
64 config GENERIC_CLOCKEVENTS
67 config GENERIC_CLOCKEVENTS_BROADCAST
69 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
71 config LOCKDEP_SUPPORT
74 config STACKTRACE_SUPPORT
77 config HAVE_LATENCYTOP_SUPPORT
80 config FAST_CMPXCHG_LOCAL
93 config GENERIC_ISA_DMA
102 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
104 config GENERIC_BUG_RELATIVE_POINTERS
107 config GENERIC_HWEIGHT
113 config ARCH_MAY_HAVE_PC_FDC
116 config RWSEM_GENERIC_SPINLOCK
119 config RWSEM_XCHGADD_ALGORITHM
122 config ARCH_HAS_CPU_IDLE_WAIT
125 config GENERIC_CALIBRATE_DELAY
128 config GENERIC_TIME_VSYSCALL
132 config ARCH_HAS_CPU_RELAX
135 config ARCH_HAS_DEFAULT_IDLE
138 config ARCH_HAS_CACHE_LINE_SIZE
141 config HAVE_SETUP_PER_CPU_AREA
144 config HAVE_DYNAMIC_PER_CPU_AREA
147 config HAVE_CPUMASK_OF_CPU_MAP
150 config ARCH_HIBERNATION_POSSIBLE
153 config ARCH_SUSPEND_POSSIBLE
160 config ARCH_POPULATES_NODE_MAP
167 config ARCH_SUPPORTS_OPTIMIZED_INLINING
170 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
173 # Use the generic interrupt handling code in kernel/irq/:
174 config GENERIC_HARDIRQS
178 config GENERIC_HARDIRQS_NO__DO_IRQ
181 config GENERIC_IRQ_PROBE
185 config GENERIC_PENDING_IRQ
187 depends on GENERIC_HARDIRQS && SMP
190 config USE_GENERIC_SMP_HELPERS
196 depends on X86_32 && SMP
200 depends on X86_64 && SMP
207 config X86_TRAMPOLINE
209 depends on SMP || (64BIT && ACPI_SLEEP)
212 config X86_32_LAZY_GS
214 depends on X86_32 && !CC_STACKPROTECTOR
218 source "init/Kconfig"
219 source "kernel/Kconfig.freezer"
221 menu "Processor type and features"
223 source "kernel/time/Kconfig"
226 bool "Symmetric multi-processing support"
228 This enables support for systems with more than one CPU. If you have
229 a system with only one CPU, like most personal computers, say N. If
230 you have a system with more than one CPU, say Y.
232 If you say N here, the kernel will run on single and multiprocessor
233 machines, but will use only one CPU of a multiprocessor machine. If
234 you say Y here, the kernel will run on many, but not all,
235 singleprocessor machines. On a singleprocessor machine, the kernel
236 will run faster if you say N here.
238 Note that if you say Y here and choose architecture "586" or
239 "Pentium" under "Processor family", the kernel will not work on 486
240 architectures. Similarly, multiprocessor kernels for the "PPro"
241 architecture may not work on all Pentium based boards.
243 People using multiprocessor machines who say Y here should also say
244 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
245 Management" code will be disabled if you say Y here.
247 See also <file:Documentation/i386/IO-APIC.txt>,
248 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
249 <http://www.tldp.org/docs.html#howto>.
251 If you don't know what to do here, say N.
254 bool "Support x2apic"
255 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
257 This enables x2apic support on CPUs that have this feature.
259 This allows 32-bit apic IDs (so it can support very large systems),
260 and accesses the local apic via MSRs not via mmio.
262 If you don't know what to do here, say N.
265 bool "Support sparse irq numbering"
266 depends on PCI_MSI || HT_IRQ
268 This enables support for sparse irqs. This is useful for distro
269 kernels that want to define a high CONFIG_NR_CPUS value but still
270 want to have low kernel memory footprint on smaller machines.
272 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
273 out the irq_desc[] array in a more NUMA-friendly way. )
275 If you don't know what to do here, say N.
278 bool "Enable MPS table" if ACPI
280 depends on X86_LOCAL_APIC
282 For old smp systems that do not have proper acpi support. Newer systems
283 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
286 bool "Support for big SMP systems with more than 8 CPUs"
287 depends on X86_32 && SMP
289 This option is needed for the systems that have more than 8 CPUs
292 config X86_EXTENDED_PLATFORM
293 bool "Support for extended (non-PC) x86 platforms"
296 If you disable this option then the kernel will only support
297 standard PC platforms. (which covers the vast majority of
300 If you enable this option then you'll be able to select support
301 for the following (non-PC) 32 bit x86 platforms:
305 SGI 320/540 (Visual Workstation)
306 Summit/EXA (IBM x440)
307 Unisys ES7000 IA32 series
309 If you have one of these systems, or if you want to build a
310 generic distribution kernel, say Y here - otherwise say N.
314 config X86_EXTENDED_PLATFORM
315 bool "Support for extended (non-PC) x86 platforms"
318 If you disable this option then the kernel will only support
319 standard PC platforms. (which covers the vast majority of
322 If you enable this option then you'll be able to select support
323 for the following (non-PC) 64 bit x86 platforms:
327 If you have one of these systems, or if you want to build a
328 generic distribution kernel, say Y here - otherwise say N.
330 # This is an alphabetically sorted list of 64 bit extended platforms
331 # Please maintain the alphabetic order if and when there are additions
336 depends on X86_64 && PCI
337 depends on X86_EXTENDED_PLATFORM
339 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
340 supposed to run on these EM64T-based machines. Only choose this option
341 if you have one of these machines.
344 bool "SGI Ultraviolet"
346 depends on X86_EXTENDED_PLATFORM
350 This option is needed in order to support SGI Ultraviolet systems.
351 If you don't have one of these, you should say N here.
353 # Following is an alphabetically sorted list of 32 bit extended platforms
354 # Please maintain the alphabetic order if and when there are additions
359 depends on X86_EXTENDED_PLATFORM
361 Select this for an AMD Elan processor.
363 Do not use this option for K6/Athlon/Opteron processors!
365 If unsure, choose "PC-compatible" instead.
368 bool "RDC R-321x SoC"
370 depends on X86_EXTENDED_PLATFORM
372 select X86_REBOOTFIXUPS
374 This option is needed for RDC R-321x system-on-chip, also known
376 If you don't have one of these chips, you should say N here.
378 config X86_32_NON_STANDARD
379 bool "Support non-standard 32-bit SMP architectures"
380 depends on X86_32 && SMP
381 depends on X86_EXTENDED_PLATFORM
383 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
384 subarchitectures. It is intended for a generic binary kernel.
385 if you select them all, kernel will probe it one by one. and will
388 # Alphabetically sorted list of Non standard 32 bit platforms
391 bool "NUMAQ (IBM/Sequent)"
392 depends on X86_32_NON_STANDARD
396 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
397 NUMA multiquad box. This changes the way that processors are
398 bootstrapped, and uses Clustered Logical APIC addressing mode instead
399 of Flat Logical. You will need a new lynxer.elf file to flash your
400 firmware with - send email to <Martin.Bligh@us.ibm.com>.
403 bool "SGI 320/540 (Visual Workstation)"
404 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
405 depends on X86_32_NON_STANDARD
407 The SGI Visual Workstation series is an IA32-based workstation
408 based on SGI systems chips with some legacy PC hardware attached.
410 Say Y here to create a kernel to run on the SGI 320 or 540.
412 A kernel compiled for the Visual Workstation will run on general
413 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
416 bool "Summit/EXA (IBM x440)"
417 depends on X86_32_NON_STANDARD
419 This option is needed for IBM systems that use the Summit/EXA chipset.
420 In particular, it is needed for the x440.
423 bool "Unisys ES7000 IA32 series"
424 depends on X86_32_NON_STANDARD && X86_BIGSMP
426 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
427 supposed to run on an IA32-based Unisys ES7000 system.
429 config SCHED_OMIT_FRAME_POINTER
431 prompt "Single-depth WCHAN output"
434 Calculate simpler /proc/<PID>/wchan values. If this option
435 is disabled then wchan values will recurse back to the
436 caller function. This provides more accurate wchan values,
437 at the expense of slightly more scheduling overhead.
439 If in doubt, say "Y".
441 menuconfig PARAVIRT_GUEST
442 bool "Paravirtualized guest support"
444 Say Y here to get to see options related to running Linux under
445 various hypervisors. This option alone does not add any kernel code.
447 If you say N, all options in this submenu will be skipped and disabled.
451 source "arch/x86/xen/Kconfig"
454 bool "VMI Guest support"
458 VMI provides a paravirtualized interface to the VMware ESX server
459 (it could be used by other hypervisors in theory too, but is not
460 at the moment), by linking the kernel to a GPL-ed ROM module
461 provided by the hypervisor.
464 bool "KVM paravirtualized clock"
466 select PARAVIRT_CLOCK
468 Turning on this option will allow you to run a paravirtualized clock
469 when running over the KVM hypervisor. Instead of relying on a PIT
470 (or probably other) emulation by the underlying device model, the host
471 provides the guest with timing infrastructure such as time of day, and
475 bool "KVM Guest support"
478 This option enables various optimizations for running under the KVM
481 source "arch/x86/lguest/Kconfig"
484 bool "Enable paravirtualization code"
486 This changes the kernel so it can modify itself when it is run
487 under a hypervisor, potentially improving performance significantly
488 over full virtualization. However, when run without a hypervisor
489 the kernel is theoretically slower and slightly larger.
491 config PARAVIRT_CLOCK
497 config PARAVIRT_DEBUG
498 bool "paravirt-ops debugging"
499 depends on PARAVIRT && DEBUG_KERNEL
501 Enable to debug paravirt_ops internals. Specifically, BUG if
502 a paravirt_op is missing when it is called.
507 This option adds a kernel parameter 'memtest', which allows memtest
509 memtest=0, mean disabled; -- default
510 memtest=1, mean do 1 test pattern;
512 memtest=4, mean do 4 test patterns.
513 If you are unsure how to answer this question, answer N.
515 config X86_SUMMIT_NUMA
517 depends on X86_32 && NUMA && X86_32_NON_STANDARD
519 config X86_CYCLONE_TIMER
521 depends on X86_32_NON_STANDARD
523 source "arch/x86/Kconfig.cpu"
527 prompt "HPET Timer Support" if X86_32
529 Use the IA-PC HPET (High Precision Event Timer) to manage
530 time in preference to the PIT and RTC, if a HPET is
532 HPET is the next generation timer replacing legacy 8254s.
533 The HPET provides a stable time base on SMP
534 systems, unlike the TSC, but it is more expensive to access,
535 as it is off-chip. You can find the HPET spec at
536 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
538 You can safely choose Y here. However, HPET will only be
539 activated if the platform and the BIOS support this feature.
540 Otherwise the 8254 will be used for timing services.
542 Choose N to continue using the legacy 8254 timer.
544 config HPET_EMULATE_RTC
546 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
548 # Mark as embedded because too many people got it wrong.
549 # The code disables itself when not needed.
552 bool "Enable DMI scanning" if EMBEDDED
554 Enabled scanning of DMI to identify machine quirks. Say Y
555 here unless you have verified that your setup is not
556 affected by entries in the DMI blacklist. Required by PNP
560 bool "GART IOMMU support" if EMBEDDED
564 depends on X86_64 && PCI
566 Support for full DMA access of devices with 32bit memory access only
567 on systems with more than 3GB. This is usually needed for USB,
568 sound, many IDE/SATA chipsets and some other devices.
569 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
570 based hardware IOMMU and a software bounce buffer based IOMMU used
571 on Intel systems and as fallback.
572 The code is only active when needed (enough memory and limited
573 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
577 bool "IBM Calgary IOMMU support"
579 depends on X86_64 && PCI && EXPERIMENTAL
581 Support for hardware IOMMUs in IBM's xSeries x366 and x460
582 systems. Needed to run systems with more than 3GB of memory
583 properly with 32-bit PCI devices that do not support DAC
584 (Double Address Cycle). Calgary also supports bus level
585 isolation, where all DMAs pass through the IOMMU. This
586 prevents them from going anywhere except their intended
587 destination. This catches hard-to-find kernel bugs and
588 mis-behaving drivers and devices that do not use the DMA-API
589 properly to set up their DMA buffers. The IOMMU can be
590 turned off at boot time with the iommu=off parameter.
591 Normally the kernel will make the right choice by itself.
594 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
596 prompt "Should Calgary be enabled by default?"
597 depends on CALGARY_IOMMU
599 Should Calgary be enabled by default? if you choose 'y', Calgary
600 will be used (if it exists). If you choose 'n', Calgary will not be
601 used even if it exists. If you choose 'n' and would like to use
602 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
606 bool "AMD IOMMU support"
609 depends on X86_64 && PCI && ACPI
611 With this option you can enable support for AMD IOMMU hardware in
612 your system. An IOMMU is a hardware component which provides
613 remapping of DMA memory accesses from devices. With an AMD IOMMU you
614 can isolate the the DMA memory of different devices and protect the
615 system from misbehaving device drivers or hardware.
617 You can find out if your system has an AMD IOMMU if you look into
618 your BIOS for an option to enable it or if you have an IVRS ACPI
621 config AMD_IOMMU_STATS
622 bool "Export AMD IOMMU statistics to debugfs"
626 This option enables code in the AMD IOMMU driver to collect various
627 statistics about whats happening in the driver and exports that
628 information to userspace via debugfs.
631 # need this always selected by IOMMU for the VIA workaround
635 Support for software bounce buffers used on x86-64 systems
636 which don't have a hardware IOMMU (e.g. the current generation
637 of Intel's x86-64 CPUs). Using this PCI devices which can only
638 access 32-bits of memory can be used on systems with more than
639 3 GB of memory. If unsure, say Y.
642 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
645 def_bool (AMD_IOMMU || DMAR)
648 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
649 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
650 select CPUMASK_OFFSTACK
653 Configure maximum number of CPUS and NUMA Nodes for this architecture.
657 int "Maximum number of CPUs" if SMP && !MAXSMP
658 range 2 8 if SMP && X86_32 && !X86_BIGSMP
659 range 2 512 if SMP && !MAXSMP
661 default "4096" if MAXSMP
662 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
665 This allows you to specify the maximum number of CPUs which this
666 kernel will support. The maximum supported value is 512 and the
667 minimum value which makes sense is 2.
669 This is purely to save memory - each supported CPU adds
670 approximately eight kilobytes to the kernel image.
673 bool "SMT (Hyperthreading) scheduler support"
676 SMT scheduler support improves the CPU scheduler's decision making
677 when dealing with Intel Pentium 4 chips with HyperThreading at a
678 cost of slightly increased overhead in some places. If unsure say
683 prompt "Multi-core scheduler support"
686 Multi-core scheduler support improves the CPU scheduler's decision
687 making when dealing with multi-core CPU chips at a cost of slightly
688 increased overhead in some places. If unsure say N here.
690 source "kernel/Kconfig.preempt"
693 bool "Local APIC support on uniprocessors"
694 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
696 A local APIC (Advanced Programmable Interrupt Controller) is an
697 integrated interrupt controller in the CPU. If you have a single-CPU
698 system which has a processor with a local APIC, you can say Y here to
699 enable and use it. If you say Y here even though your machine doesn't
700 have a local APIC, then the kernel will still run with no slowdown at
701 all. The local APIC supports CPU-generated self-interrupts (timer,
702 performance counters), and the NMI watchdog which detects hard
706 bool "IO-APIC support on uniprocessors"
707 depends on X86_UP_APIC
709 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
710 SMP-capable replacement for PC-style interrupt controllers. Most
711 SMP systems and many recent uniprocessor systems have one.
713 If you have a single-CPU system with an IO-APIC, you can say Y here
714 to use it. If you say Y here even though your machine doesn't have
715 an IO-APIC, then the kernel will still run with no slowdown at all.
717 config X86_LOCAL_APIC
719 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
723 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
725 config X86_VISWS_APIC
727 depends on X86_32 && X86_VISWS
729 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
730 bool "Reroute for broken boot IRQs"
732 depends on X86_IO_APIC
734 This option enables a workaround that fixes a source of
735 spurious interrupts. This is recommended when threaded
736 interrupt handling is used on systems where the generation of
737 superfluous "boot interrupts" cannot be disabled.
739 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
740 entry in the chipset's IO-APIC is masked (as, e.g. the RT
741 kernel does during interrupt handling). On chipsets where this
742 boot IRQ generation cannot be disabled, this workaround keeps
743 the original IRQ line masked so that only the equivalent "boot
744 IRQ" is delivered to the CPUs. The workaround also tells the
745 kernel to set up the IRQ handler on the boot IRQ line. In this
746 way only one interrupt is delivered to the kernel. Otherwise
747 the spurious second interrupt may cause the kernel to bring
748 down (vital) interrupt lines.
750 Only affects "broken" chipsets. Interrupt sharing may be
751 increased on these systems.
754 bool "Machine Check Exception"
756 Machine Check Exception support allows the processor to notify the
757 kernel if it detects a problem (e.g. overheating, component failure).
758 The action the kernel takes depends on the severity of the problem,
759 ranging from a warning message on the console, to halting the machine.
760 Your processor must be a Pentium or newer to support this - check the
761 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
762 have a design flaw which leads to false MCE events - hence MCE is
763 disabled on all P5 processors, unless explicitly enabled with "mce"
764 as a boot argument. Similarly, if MCE is built in and creates a
765 problem on some new non-standard machine, you can boot with "nomce"
766 to disable it. MCE support simply ignores non-MCE processors like
767 the 386 and 486, so nearly everyone can say Y here.
771 prompt "Intel MCE features"
772 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
774 Additional support for intel specific MCE features such as
779 prompt "AMD MCE features"
780 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
782 Additional support for AMD specific MCE features such as
783 the DRAM Error Threshold.
785 config X86_MCE_THRESHOLD
786 depends on X86_MCE_AMD || X86_MCE_INTEL
790 config X86_MCE_NONFATAL
791 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
792 depends on X86_32 && X86_MCE
794 Enabling this feature starts a timer that triggers every 5 seconds which
795 will look at the machine check registers to see if anything happened.
796 Non-fatal problems automatically get corrected (but still logged).
797 Disable this if you don't want to see these messages.
798 Seeing the messages this option prints out may be indicative of dying
799 or out-of-spec (ie, overclocked) hardware.
800 This option only does something on certain CPUs.
801 (AMD Athlon/Duron and Intel Pentium 4)
803 config X86_MCE_P4THERMAL
804 bool "check for P4 thermal throttling interrupt."
805 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
807 Enabling this feature will cause a message to be printed when the P4
808 enters thermal throttling.
811 bool "Enable VM86 support" if EMBEDDED
815 This option is required by programs like DOSEMU to run 16-bit legacy
816 code on X86 processors. It also may be needed by software like
817 XFree86 to initialize some video cards via BIOS. Disabling this
818 option saves about 6k.
821 tristate "Toshiba Laptop support"
824 This adds a driver to safely access the System Management Mode of
825 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
826 not work on models with a Phoenix BIOS. The System Management Mode
827 is used to set the BIOS and power saving options on Toshiba portables.
829 For information on utilities to make use of this driver see the
830 Toshiba Linux utilities web site at:
831 <http://www.buzzard.org.uk/toshiba/>.
833 Say Y if you intend to run this kernel on a Toshiba portable.
837 tristate "Dell laptop support"
839 This adds a driver to safely access the System Management Mode
840 of the CPU on the Dell Inspiron 8000. The System Management Mode
841 is used to read cpu temperature and cooling fan status and to
842 control the fans on the I8K portables.
844 This driver has been tested only on the Inspiron 8000 but it may
845 also work with other Dell laptops. You can force loading on other
846 models by passing the parameter `force=1' to the module. Use at
849 For information on utilities to make use of this driver see the
850 I8K Linux utilities web site at:
851 <http://people.debian.org/~dz/i8k/>
853 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
856 config X86_REBOOTFIXUPS
857 bool "Enable X86 board specific fixups for reboot"
860 This enables chipset and/or board specific fixups to be done
861 in order to get reboot to work correctly. This is only needed on
862 some combinations of hardware and BIOS. The symptom, for which
863 this config is intended, is when reboot ends with a stalled/hung
866 Currently, the only fixup is for the Geode machines using
867 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
869 Say Y if you want to enable the fixup. Currently, it's safe to
870 enable this option even if you don't need it.
874 tristate "/dev/cpu/microcode - microcode support"
877 If you say Y here, you will be able to update the microcode on
878 certain Intel and AMD processors. The Intel support is for the
879 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
880 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
881 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
882 You will obviously need the actual microcode binary data itself
883 which is not shipped with the Linux kernel.
885 This option selects the general module only, you need to select
886 at least one vendor specific module as well.
888 To compile this driver as a module, choose M here: the
889 module will be called microcode.
891 config MICROCODE_INTEL
892 bool "Intel microcode patch loading support"
897 This options enables microcode patch loading support for Intel
900 For latest news and information on obtaining all the required
901 Intel ingredients for this driver, check:
902 <http://www.urbanmyth.org/microcode/>.
905 bool "AMD microcode patch loading support"
909 If you select this option, microcode patch loading support for AMD
910 processors will be enabled.
912 config MICROCODE_OLD_INTERFACE
917 tristate "/dev/cpu/*/msr - Model-specific register support"
919 This device gives privileged processes access to the x86
920 Model-Specific Registers (MSRs). It is a character device with
921 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
922 MSR accesses are directed to a specific CPU on multi-processor
926 tristate "/dev/cpu/*/cpuid - CPU information support"
928 This device gives processes access to the x86 CPUID instruction to
929 be executed on a specific processor. It is a character device
930 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
934 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
936 If you select this option, this will provide various x86 CPUs
937 information through debugfs.
940 prompt "High Memory Support"
941 default HIGHMEM4G if !X86_NUMAQ
942 default HIGHMEM64G if X86_NUMAQ
947 depends on !X86_NUMAQ
949 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
950 However, the address space of 32-bit x86 processors is only 4
951 Gigabytes large. That means that, if you have a large amount of
952 physical memory, not all of it can be "permanently mapped" by the
953 kernel. The physical memory that's not permanently mapped is called
956 If you are compiling a kernel which will never run on a machine with
957 more than 1 Gigabyte total physical RAM, answer "off" here (default
958 choice and suitable for most users). This will result in a "3GB/1GB"
959 split: 3GB are mapped so that each process sees a 3GB virtual memory
960 space and the remaining part of the 4GB virtual memory space is used
961 by the kernel to permanently map as much physical memory as
964 If the machine has between 1 and 4 Gigabytes physical RAM, then
967 If more than 4 Gigabytes is used then answer "64GB" here. This
968 selection turns Intel PAE (Physical Address Extension) mode on.
969 PAE implements 3-level paging on IA32 processors. PAE is fully
970 supported by Linux, PAE mode is implemented on all recent Intel
971 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
972 then the kernel will not boot on CPUs that don't support PAE!
974 The actual amount of total physical memory will either be
975 auto detected or can be forced by using a kernel command line option
976 such as "mem=256M". (Try "man bootparam" or see the documentation of
977 your boot loader (lilo or loadlin) about how to pass options to the
978 kernel at boot time.)
980 If unsure, say "off".
984 depends on !X86_NUMAQ
986 Select this if you have a 32-bit processor and between 1 and 4
987 gigabytes of physical RAM.
991 depends on !M386 && !M486
994 Select this if you have a 32-bit processor and more than 4
995 gigabytes of physical RAM.
1000 depends on EXPERIMENTAL
1001 prompt "Memory split" if EMBEDDED
1005 Select the desired split between kernel and user memory.
1007 If the address range available to the kernel is less than the
1008 physical memory installed, the remaining memory will be available
1009 as "high memory". Accessing high memory is a little more costly
1010 than low memory, as it needs to be mapped into the kernel first.
1011 Note that increasing the kernel address space limits the range
1012 available to user programs, making the address space there
1013 tighter. Selecting anything other than the default 3G/1G split
1014 will also likely make your kernel incompatible with binary-only
1017 If you are not absolutely sure what you are doing, leave this
1021 bool "3G/1G user/kernel split"
1022 config VMSPLIT_3G_OPT
1024 bool "3G/1G user/kernel split (for full 1G low memory)"
1026 bool "2G/2G user/kernel split"
1027 config VMSPLIT_2G_OPT
1029 bool "2G/2G user/kernel split (for full 2G low memory)"
1031 bool "1G/3G user/kernel split"
1036 default 0xB0000000 if VMSPLIT_3G_OPT
1037 default 0x80000000 if VMSPLIT_2G
1038 default 0x78000000 if VMSPLIT_2G_OPT
1039 default 0x40000000 if VMSPLIT_1G
1045 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1048 bool "PAE (Physical Address Extension) Support"
1049 depends on X86_32 && !HIGHMEM4G
1051 PAE is required for NX support, and furthermore enables
1052 larger swapspace support for non-overcommit purposes. It
1053 has the cost of more pagetable lookup overhead, and also
1054 consumes more pagetable space per process.
1056 config ARCH_PHYS_ADDR_T_64BIT
1057 def_bool X86_64 || X86_PAE
1059 config DIRECT_GBPAGES
1060 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1064 Allow the kernel linear mapping to use 1GB pages on CPUs that
1065 support it. This can improve the kernel's performance a tiny bit by
1066 reducing TLB pressure. If in doubt, say "Y".
1068 # Common NUMA Features
1070 bool "Numa Memory Allocation and Scheduler Support"
1072 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1073 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1075 Enable NUMA (Non Uniform Memory Access) support.
1077 The kernel will try to allocate memory used by a CPU on the
1078 local memory controller of the CPU and add some more
1079 NUMA awareness to the kernel.
1081 For 64-bit this is recommended if the system is Intel Core i7
1082 (or later), AMD Opteron, or EM64T NUMA.
1084 For 32-bit this is only needed on (rare) 32-bit-only platforms
1085 that support NUMA topologies, such as NUMAQ / Summit, or if you
1086 boot a 32-bit kernel on a 64-bit NUMA platform.
1088 Otherwise, you should say N.
1090 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1091 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1095 prompt "Old style AMD Opteron NUMA detection"
1096 depends on X86_64 && NUMA && PCI
1098 Enable K8 NUMA node topology detection. You should say Y here if
1099 you have a multi processor AMD K8 system. This uses an old
1100 method to read the NUMA configuration directly from the builtin
1101 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1102 instead, which also takes priority if both are compiled in.
1104 config X86_64_ACPI_NUMA
1106 prompt "ACPI NUMA detection"
1107 depends on X86_64 && NUMA && ACPI && PCI
1110 Enable ACPI SRAT based node topology detection.
1112 # Some NUMA nodes have memory ranges that span
1113 # other nodes. Even though a pfn is valid and
1114 # between a node's start and end pfns, it may not
1115 # reside on that node. See memmap_init_zone()
1117 config NODES_SPAN_OTHER_NODES
1119 depends on X86_64_ACPI_NUMA
1122 bool "NUMA emulation"
1123 depends on X86_64 && NUMA
1125 Enable NUMA emulation. A flat machine will be split
1126 into virtual nodes when booted with "numa=fake=N", where N is the
1127 number of nodes. This is only useful for debugging.
1130 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1132 default "9" if MAXSMP
1133 default "6" if X86_64
1134 default "4" if X86_NUMAQ
1136 depends on NEED_MULTIPLE_NODES
1138 Specify the maximum number of NUMA Nodes available on the target
1139 system. Increases memory reserved to accommodate various tables.
1141 config HAVE_ARCH_BOOTMEM
1143 depends on X86_32 && NUMA
1145 config ARCH_HAVE_MEMORY_PRESENT
1147 depends on X86_32 && DISCONTIGMEM
1149 config NEED_NODE_MEMMAP_SIZE
1151 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1153 config HAVE_ARCH_ALLOC_REMAP
1155 depends on X86_32 && NUMA
1157 config ARCH_FLATMEM_ENABLE
1159 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1161 config ARCH_DISCONTIGMEM_ENABLE
1163 depends on NUMA && X86_32
1165 config ARCH_DISCONTIGMEM_DEFAULT
1167 depends on NUMA && X86_32
1169 config ARCH_SPARSEMEM_DEFAULT
1173 config ARCH_SPARSEMEM_ENABLE
1175 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1176 select SPARSEMEM_STATIC if X86_32
1177 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1179 config ARCH_SELECT_MEMORY_MODEL
1181 depends on ARCH_SPARSEMEM_ENABLE
1183 config ARCH_MEMORY_PROBE
1185 depends on MEMORY_HOTPLUG
1190 bool "Allocate 3rd-level pagetables from highmem"
1191 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1193 The VM uses one page table entry for each page of physical memory.
1194 For systems with a lot of RAM, this can be wasteful of precious
1195 low memory. Setting this option will put user-space page table
1196 entries in high memory.
1198 config X86_CHECK_BIOS_CORRUPTION
1199 bool "Check for low memory corruption"
1201 Periodically check for memory corruption in low memory, which
1202 is suspected to be caused by BIOS. Even when enabled in the
1203 configuration, it is disabled at runtime. Enable it by
1204 setting "memory_corruption_check=1" on the kernel command
1205 line. By default it scans the low 64k of memory every 60
1206 seconds; see the memory_corruption_check_size and
1207 memory_corruption_check_period parameters in
1208 Documentation/kernel-parameters.txt to adjust this.
1210 When enabled with the default parameters, this option has
1211 almost no overhead, as it reserves a relatively small amount
1212 of memory and scans it infrequently. It both detects corruption
1213 and prevents it from affecting the running system.
1215 It is, however, intended as a diagnostic tool; if repeatable
1216 BIOS-originated corruption always affects the same memory,
1217 you can use memmap= to prevent the kernel from using that
1220 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1221 bool "Set the default setting of memory_corruption_check"
1222 depends on X86_CHECK_BIOS_CORRUPTION
1225 Set whether the default state of memory_corruption_check is
1228 config X86_RESERVE_LOW_64K
1229 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1232 Reserve the first 64K of physical RAM on BIOSes that are known
1233 to potentially corrupt that memory range. A numbers of BIOSes are
1234 known to utilize this area during suspend/resume, so it must not
1235 be used by the kernel.
1237 Set this to N if you are absolutely sure that you trust the BIOS
1238 to get all its memory reservations and usages right.
1240 If you have doubts about the BIOS (e.g. suspend/resume does not
1241 work or there's kernel crashes after certain hardware hotplug
1242 events) and it's not AMI or Phoenix, then you might want to enable
1243 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1244 corruption patterns.
1248 config MATH_EMULATION
1250 prompt "Math emulation" if X86_32
1252 Linux can emulate a math coprocessor (used for floating point
1253 operations) if you don't have one. 486DX and Pentium processors have
1254 a math coprocessor built in, 486SX and 386 do not, unless you added
1255 a 487DX or 387, respectively. (The messages during boot time can
1256 give you some hints here ["man dmesg"].) Everyone needs either a
1257 coprocessor or this emulation.
1259 If you don't have a math coprocessor, you need to say Y here; if you
1260 say Y here even though you have a coprocessor, the coprocessor will
1261 be used nevertheless. (This behavior can be changed with the kernel
1262 command line option "no387", which comes handy if your coprocessor
1263 is broken. Try "man bootparam" or see the documentation of your boot
1264 loader (lilo or loadlin) about how to pass options to the kernel at
1265 boot time.) This means that it is a good idea to say Y here if you
1266 intend to use this kernel on different machines.
1268 More information about the internals of the Linux math coprocessor
1269 emulation can be found in <file:arch/x86/math-emu/README>.
1271 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1272 kernel, it won't hurt.
1275 bool "MTRR (Memory Type Range Register) support"
1277 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1278 the Memory Type Range Registers (MTRRs) may be used to control
1279 processor access to memory ranges. This is most useful if you have
1280 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1281 allows bus write transfers to be combined into a larger transfer
1282 before bursting over the PCI/AGP bus. This can increase performance
1283 of image write operations 2.5 times or more. Saying Y here creates a
1284 /proc/mtrr file which may be used to manipulate your processor's
1285 MTRRs. Typically the X server should use this.
1287 This code has a reasonably generic interface so that similar
1288 control registers on other processors can be easily supported
1291 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1292 Registers (ARRs) which provide a similar functionality to MTRRs. For
1293 these, the ARRs are used to emulate the MTRRs.
1294 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1295 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1296 write-combining. All of these processors are supported by this code
1297 and it makes sense to say Y here if you have one of them.
1299 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1300 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1301 can lead to all sorts of problems, so it's good to say Y here.
1303 You can safely say Y even if your machine doesn't have MTRRs, you'll
1304 just add about 9 KB to your kernel.
1306 See <file:Documentation/x86/mtrr.txt> for more information.
1308 config MTRR_SANITIZER
1310 prompt "MTRR cleanup support"
1313 Convert MTRR layout from continuous to discrete, so X drivers can
1314 add writeback entries.
1316 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1317 The largest mtrr entry size for a continuous block can be set with
1322 config MTRR_SANITIZER_ENABLE_DEFAULT
1323 int "MTRR cleanup enable value (0-1)"
1326 depends on MTRR_SANITIZER
1328 Enable mtrr cleanup default value
1330 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1331 int "MTRR cleanup spare reg num (0-7)"
1334 depends on MTRR_SANITIZER
1336 mtrr cleanup spare entries default, it can be changed via
1337 mtrr_spare_reg_nr=N on the kernel command line.
1341 prompt "x86 PAT support"
1344 Use PAT attributes to setup page level cache control.
1346 PATs are the modern equivalents of MTRRs and are much more
1347 flexible than MTRRs.
1349 Say N here if you see bootup problems (boot crash, boot hang,
1350 spontaneous reboots) or a non-working video driver.
1355 bool "EFI runtime service support"
1358 This enables the kernel to use EFI runtime services that are
1359 available (such as the EFI variable services).
1361 This option is only useful on systems that have EFI firmware.
1362 In addition, you should use the latest ELILO loader available
1363 at <http://elilo.sourceforge.net> in order to take advantage
1364 of EFI runtime services. However, even with this option, the
1365 resultant kernel should continue to boot on existing non-EFI
1370 prompt "Enable seccomp to safely compute untrusted bytecode"
1372 This kernel feature is useful for number crunching applications
1373 that may need to compute untrusted bytecode during their
1374 execution. By using pipes or other transports made available to
1375 the process as file descriptors supporting the read/write
1376 syscalls, it's possible to isolate those applications in
1377 their own address space using seccomp. Once seccomp is
1378 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1379 and the task is only allowed to execute a few safe syscalls
1380 defined by each seccomp mode.
1382 If unsure, say Y. Only embedded should say N here.
1384 config CC_STACKPROTECTOR_ALL
1387 config CC_STACKPROTECTOR
1388 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1389 select CC_STACKPROTECTOR_ALL
1391 This option turns on the -fstack-protector GCC feature. This
1392 feature puts, at the beginning of functions, a canary value on
1393 the stack just before the return address, and validates
1394 the value just before actually returning. Stack based buffer
1395 overflows (that need to overwrite this return address) now also
1396 overwrite the canary, which gets detected and the attack is then
1397 neutralized via a kernel panic.
1399 This feature requires gcc version 4.2 or above, or a distribution
1400 gcc with the feature backported. Older versions are automatically
1401 detected and for those versions, this configuration option is
1402 ignored. (and a warning is printed during bootup)
1404 source kernel/Kconfig.hz
1407 bool "kexec system call"
1409 kexec is a system call that implements the ability to shutdown your
1410 current kernel, and to start another kernel. It is like a reboot
1411 but it is independent of the system firmware. And like a reboot
1412 you can start any kernel with it, not just Linux.
1414 The name comes from the similarity to the exec system call.
1416 It is an ongoing process to be certain the hardware in a machine
1417 is properly shutdown, so do not be surprised if this code does not
1418 initially work for you. It may help to enable device hotplugging
1419 support. As of this writing the exact hardware interface is
1420 strongly in flux, so no good recommendation can be made.
1423 bool "kernel crash dumps"
1424 depends on X86_64 || (X86_32 && HIGHMEM)
1426 Generate crash dump after being started by kexec.
1427 This should be normally only set in special crash dump kernels
1428 which are loaded in the main kernel with kexec-tools into
1429 a specially reserved region and then later executed after
1430 a crash by kdump/kexec. The crash dump kernel must be compiled
1431 to a memory address not used by the main kernel or BIOS using
1432 PHYSICAL_START, or it must be built as a relocatable image
1433 (CONFIG_RELOCATABLE=y).
1434 For more details see Documentation/kdump/kdump.txt
1437 bool "kexec jump (EXPERIMENTAL)"
1438 depends on EXPERIMENTAL
1439 depends on KEXEC && HIBERNATION
1441 Jump between original kernel and kexeced kernel and invoke
1442 code in physical address mode via KEXEC
1444 config PHYSICAL_START
1445 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1446 default "0x1000000" if X86_NUMAQ
1447 default "0x200000" if X86_64
1450 This gives the physical address where the kernel is loaded.
1452 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1453 bzImage will decompress itself to above physical address and
1454 run from there. Otherwise, bzImage will run from the address where
1455 it has been loaded by the boot loader and will ignore above physical
1458 In normal kdump cases one does not have to set/change this option
1459 as now bzImage can be compiled as a completely relocatable image
1460 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1461 address. This option is mainly useful for the folks who don't want
1462 to use a bzImage for capturing the crash dump and want to use a
1463 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1464 to be specifically compiled to run from a specific memory area
1465 (normally a reserved region) and this option comes handy.
1467 So if you are using bzImage for capturing the crash dump, leave
1468 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1469 Otherwise if you plan to use vmlinux for capturing the crash dump
1470 change this value to start of the reserved region (Typically 16MB
1471 0x1000000). In other words, it can be set based on the "X" value as
1472 specified in the "crashkernel=YM@XM" command line boot parameter
1473 passed to the panic-ed kernel. Typically this parameter is set as
1474 crashkernel=64M@16M. Please take a look at
1475 Documentation/kdump/kdump.txt for more details about crash dumps.
1477 Usage of bzImage for capturing the crash dump is recommended as
1478 one does not have to build two kernels. Same kernel can be used
1479 as production kernel and capture kernel. Above option should have
1480 gone away after relocatable bzImage support is introduced. But it
1481 is present because there are users out there who continue to use
1482 vmlinux for dump capture. This option should go away down the
1485 Don't change this unless you know what you are doing.
1488 bool "Build a relocatable kernel (EXPERIMENTAL)"
1489 depends on EXPERIMENTAL
1491 This builds a kernel image that retains relocation information
1492 so it can be loaded someplace besides the default 1MB.
1493 The relocations tend to make the kernel binary about 10% larger,
1494 but are discarded at runtime.
1496 One use is for the kexec on panic case where the recovery kernel
1497 must live at a different physical address than the primary
1500 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1501 it has been loaded at and the compile time physical address
1502 (CONFIG_PHYSICAL_START) is ignored.
1504 config PHYSICAL_ALIGN
1506 prompt "Alignment value to which kernel should be aligned" if X86_32
1507 default "0x100000" if X86_32
1508 default "0x200000" if X86_64
1509 range 0x2000 0x400000
1511 This value puts the alignment restrictions on physical address
1512 where kernel is loaded and run from. Kernel is compiled for an
1513 address which meets above alignment restriction.
1515 If bootloader loads the kernel at a non-aligned address and
1516 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1517 address aligned to above value and run from there.
1519 If bootloader loads the kernel at a non-aligned address and
1520 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1521 load address and decompress itself to the address it has been
1522 compiled for and run from there. The address for which kernel is
1523 compiled already meets above alignment restrictions. Hence the
1524 end result is that kernel runs from a physical address meeting
1525 above alignment restrictions.
1527 Don't change this unless you know what you are doing.
1530 bool "Support for hot-pluggable CPUs"
1531 depends on SMP && HOTPLUG
1533 Say Y here to allow turning CPUs off and on. CPUs can be
1534 controlled through /sys/devices/system/cpu.
1535 ( Note: power management support will enable this option
1536 automatically on SMP systems. )
1537 Say N if you want to disable CPU hotplug.
1541 prompt "Compat VDSO support"
1542 depends on X86_32 || IA32_EMULATION
1544 Map the 32-bit VDSO to the predictable old-style address too.
1546 Say N here if you are running a sufficiently recent glibc
1547 version (2.3.3 or later), to remove the high-mapped
1548 VDSO mapping and to exclusively use the randomized VDSO.
1553 bool "Built-in kernel command line"
1556 Allow for specifying boot arguments to the kernel at
1557 build time. On some systems (e.g. embedded ones), it is
1558 necessary or convenient to provide some or all of the
1559 kernel boot arguments with the kernel itself (that is,
1560 to not rely on the boot loader to provide them.)
1562 To compile command line arguments into the kernel,
1563 set this option to 'Y', then fill in the
1564 the boot arguments in CONFIG_CMDLINE.
1566 Systems with fully functional boot loaders (i.e. non-embedded)
1567 should leave this option set to 'N'.
1570 string "Built-in kernel command string"
1571 depends on CMDLINE_BOOL
1574 Enter arguments here that should be compiled into the kernel
1575 image and used at boot time. If the boot loader provides a
1576 command line at boot time, it is appended to this string to
1577 form the full kernel command line, when the system boots.
1579 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1580 change this behavior.
1582 In most cases, the command line (whether built-in or provided
1583 by the boot loader) should specify the device for the root
1586 config CMDLINE_OVERRIDE
1587 bool "Built-in command line overrides boot loader arguments"
1589 depends on CMDLINE_BOOL
1591 Set this option to 'Y' to have the kernel ignore the boot loader
1592 command line, and use ONLY the built-in command line.
1594 This is used to work around broken boot loaders. This should
1595 be set to 'N' under normal conditions.
1599 config ARCH_ENABLE_MEMORY_HOTPLUG
1601 depends on X86_64 || (X86_32 && HIGHMEM)
1603 config ARCH_ENABLE_MEMORY_HOTREMOVE
1605 depends on MEMORY_HOTPLUG
1607 config HAVE_ARCH_EARLY_PFN_TO_NID
1611 menu "Power management and ACPI options"
1613 config ARCH_HIBERNATION_HEADER
1615 depends on X86_64 && HIBERNATION
1617 source "kernel/power/Kconfig"
1619 source "drivers/acpi/Kconfig"
1624 depends on APM || APM_MODULE
1627 tristate "APM (Advanced Power Management) BIOS support"
1628 depends on X86_32 && PM_SLEEP
1630 APM is a BIOS specification for saving power using several different
1631 techniques. This is mostly useful for battery powered laptops with
1632 APM compliant BIOSes. If you say Y here, the system time will be
1633 reset after a RESUME operation, the /proc/apm device will provide
1634 battery status information, and user-space programs will receive
1635 notification of APM "events" (e.g. battery status change).
1637 If you select "Y" here, you can disable actual use of the APM
1638 BIOS by passing the "apm=off" option to the kernel at boot time.
1640 Note that the APM support is almost completely disabled for
1641 machines with more than one CPU.
1643 In order to use APM, you will need supporting software. For location
1644 and more information, read <file:Documentation/power/pm.txt> and the
1645 Battery Powered Linux mini-HOWTO, available from
1646 <http://www.tldp.org/docs.html#howto>.
1648 This driver does not spin down disk drives (see the hdparm(8)
1649 manpage ("man 8 hdparm") for that), and it doesn't turn off
1650 VESA-compliant "green" monitors.
1652 This driver does not support the TI 4000M TravelMate and the ACER
1653 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1654 desktop machines also don't have compliant BIOSes, and this driver
1655 may cause those machines to panic during the boot phase.
1657 Generally, if you don't have a battery in your machine, there isn't
1658 much point in using this driver and you should say N. If you get
1659 random kernel OOPSes or reboots that don't seem to be related to
1660 anything, try disabling/enabling this option (or disabling/enabling
1663 Some other things you should try when experiencing seemingly random,
1666 1) make sure that you have enough swap space and that it is
1668 2) pass the "no-hlt" option to the kernel
1669 3) switch on floating point emulation in the kernel and pass
1670 the "no387" option to the kernel
1671 4) pass the "floppy=nodma" option to the kernel
1672 5) pass the "mem=4M" option to the kernel (thereby disabling
1673 all but the first 4 MB of RAM)
1674 6) make sure that the CPU is not over clocked.
1675 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1676 8) disable the cache from your BIOS settings
1677 9) install a fan for the video card or exchange video RAM
1678 10) install a better fan for the CPU
1679 11) exchange RAM chips
1680 12) exchange the motherboard.
1682 To compile this driver as a module, choose M here: the
1683 module will be called apm.
1687 config APM_IGNORE_USER_SUSPEND
1688 bool "Ignore USER SUSPEND"
1690 This option will ignore USER SUSPEND requests. On machines with a
1691 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1692 series notebooks, it is necessary to say Y because of a BIOS bug.
1694 config APM_DO_ENABLE
1695 bool "Enable PM at boot time"
1697 Enable APM features at boot time. From page 36 of the APM BIOS
1698 specification: "When disabled, the APM BIOS does not automatically
1699 power manage devices, enter the Standby State, enter the Suspend
1700 State, or take power saving steps in response to CPU Idle calls."
1701 This driver will make CPU Idle calls when Linux is idle (unless this
1702 feature is turned off -- see "Do CPU IDLE calls", below). This
1703 should always save battery power, but more complicated APM features
1704 will be dependent on your BIOS implementation. You may need to turn
1705 this option off if your computer hangs at boot time when using APM
1706 support, or if it beeps continuously instead of suspending. Turn
1707 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1708 T400CDT. This is off by default since most machines do fine without
1712 bool "Make CPU Idle calls when idle"
1714 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1715 On some machines, this can activate improved power savings, such as
1716 a slowed CPU clock rate, when the machine is idle. These idle calls
1717 are made after the idle loop has run for some length of time (e.g.,
1718 333 mS). On some machines, this will cause a hang at boot time or
1719 whenever the CPU becomes idle. (On machines with more than one CPU,
1720 this option does nothing.)
1722 config APM_DISPLAY_BLANK
1723 bool "Enable console blanking using APM"
1725 Enable console blanking using the APM. Some laptops can use this to
1726 turn off the LCD backlight when the screen blanker of the Linux
1727 virtual console blanks the screen. Note that this is only used by
1728 the virtual console screen blanker, and won't turn off the backlight
1729 when using the X Window system. This also doesn't have anything to
1730 do with your VESA-compliant power-saving monitor. Further, this
1731 option doesn't work for all laptops -- it might not turn off your
1732 backlight at all, or it might print a lot of errors to the console,
1733 especially if you are using gpm.
1735 config APM_ALLOW_INTS
1736 bool "Allow interrupts during APM BIOS calls"
1738 Normally we disable external interrupts while we are making calls to
1739 the APM BIOS as a measure to lessen the effects of a badly behaving
1740 BIOS implementation. The BIOS should reenable interrupts if it
1741 needs to. Unfortunately, some BIOSes do not -- especially those in
1742 many of the newer IBM Thinkpads. If you experience hangs when you
1743 suspend, try setting this to Y. Otherwise, say N.
1747 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1749 source "drivers/cpuidle/Kconfig"
1751 source "drivers/idle/Kconfig"
1756 menu "Bus options (PCI etc.)"
1761 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1763 Find out whether you have a PCI motherboard. PCI is the name of a
1764 bus system, i.e. the way the CPU talks to the other stuff inside
1765 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1766 VESA. If you have PCI, say Y, otherwise N.
1769 prompt "PCI access mode"
1770 depends on X86_32 && PCI
1773 On PCI systems, the BIOS can be used to detect the PCI devices and
1774 determine their configuration. However, some old PCI motherboards
1775 have BIOS bugs and may crash if this is done. Also, some embedded
1776 PCI-based systems don't have any BIOS at all. Linux can also try to
1777 detect the PCI hardware directly without using the BIOS.
1779 With this option, you can specify how Linux should detect the
1780 PCI devices. If you choose "BIOS", the BIOS will be used,
1781 if you choose "Direct", the BIOS won't be used, and if you
1782 choose "MMConfig", then PCI Express MMCONFIG will be used.
1783 If you choose "Any", the kernel will try MMCONFIG, then the
1784 direct access method and falls back to the BIOS if that doesn't
1785 work. If unsure, go with the default, which is "Any".
1790 config PCI_GOMMCONFIG
1807 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1809 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1812 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1816 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1820 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1827 bool "Support mmconfig PCI config space access"
1828 depends on X86_64 && PCI && ACPI
1831 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1832 depends on PCI_MSI && ACPI && EXPERIMENTAL
1834 DMA remapping (DMAR) devices support enables independent address
1835 translations for Direct Memory Access (DMA) from devices.
1836 These DMA remapping devices are reported via ACPI tables
1837 and include PCI device scope covered by these DMA
1840 config DMAR_DEFAULT_ON
1842 prompt "Enable DMA Remapping Devices by default"
1845 Selecting this option will enable a DMAR device at boot time if
1846 one is found. If this option is not selected, DMAR support can
1847 be enabled by passing intel_iommu=on to the kernel. It is
1848 recommended you say N here while the DMAR code remains
1853 prompt "Support for Graphics workaround"
1856 Current Graphics drivers tend to use physical address
1857 for DMA and avoid using DMA APIs. Setting this config
1858 option permits the IOMMU driver to set a unity map for
1859 all the OS-visible memory. Hence the driver can continue
1860 to use physical addresses for DMA.
1862 config DMAR_FLOPPY_WA
1866 Floppy disk drivers are know to bypass DMA API calls
1867 thereby failing to work when IOMMU is enabled. This
1868 workaround will setup a 1:1 mapping for the first
1869 16M to make floppy (an ISA device) work.
1872 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1873 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1875 Supports Interrupt remapping for IO-APIC and MSI devices.
1876 To use x2apic mode in the CPU's which support x2APIC enhancements or
1877 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1879 source "drivers/pci/pcie/Kconfig"
1881 source "drivers/pci/Kconfig"
1883 # x86_64 have no ISA slots, but do have ISA-style DMA.
1892 Find out whether you have ISA slots on your motherboard. ISA is the
1893 name of a bus system, i.e. the way the CPU talks to the other stuff
1894 inside your box. Other bus systems are PCI, EISA, MicroChannel
1895 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1896 newer boards don't support it. If you have ISA, say Y, otherwise N.
1902 The Extended Industry Standard Architecture (EISA) bus was
1903 developed as an open alternative to the IBM MicroChannel bus.
1905 The EISA bus provided some of the features of the IBM MicroChannel
1906 bus while maintaining backward compatibility with cards made for
1907 the older ISA bus. The EISA bus saw limited use between 1988 and
1908 1995 when it was made obsolete by the PCI bus.
1910 Say Y here if you are building a kernel for an EISA-based machine.
1914 source "drivers/eisa/Kconfig"
1919 MicroChannel Architecture is found in some IBM PS/2 machines and
1920 laptops. It is a bus system similar to PCI or ISA. See
1921 <file:Documentation/mca.txt> (and especially the web page given
1922 there) before attempting to build an MCA bus kernel.
1924 source "drivers/mca/Kconfig"
1927 tristate "NatSemi SCx200 support"
1929 This provides basic support for National Semiconductor's
1930 (now AMD's) Geode processors. The driver probes for the
1931 PCI-IDs of several on-chip devices, so its a good dependency
1932 for other scx200_* drivers.
1934 If compiled as a module, the driver is named scx200.
1936 config SCx200HR_TIMER
1937 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1938 depends on SCx200 && GENERIC_TIME
1941 This driver provides a clocksource built upon the on-chip
1942 27MHz high-resolution timer. Its also a workaround for
1943 NSC Geode SC-1100's buggy TSC, which loses time when the
1944 processor goes idle (as is done by the scheduler). The
1945 other workaround is idle=poll boot option.
1947 config GEODE_MFGPT_TIMER
1949 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1950 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1952 This driver provides a clock event source based on the MFGPT
1953 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1954 MFGPTs have a better resolution and max interval than the
1955 generic PIT, and are suitable for use as high-res timers.
1958 bool "One Laptop Per Child support"
1961 Add support for detecting the unique features of the OLPC
1968 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1970 source "drivers/pcmcia/Kconfig"
1972 source "drivers/pci/hotplug/Kconfig"
1977 menu "Executable file formats / Emulations"
1979 source "fs/Kconfig.binfmt"
1981 config IA32_EMULATION
1982 bool "IA32 Emulation"
1984 select COMPAT_BINFMT_ELF
1986 Include code to run 32-bit programs under a 64-bit kernel. You should
1987 likely turn this on, unless you're 100% sure that you don't have any
1988 32-bit programs left.
1991 tristate "IA32 a.out support"
1992 depends on IA32_EMULATION
1994 Support old a.out binaries in the 32bit emulation.
1998 depends on IA32_EMULATION
2000 config COMPAT_FOR_U64_ALIGNMENT
2004 config SYSVIPC_COMPAT
2006 depends on COMPAT && SYSVIPC
2011 config HAVE_ATOMIC_IOMAP
2015 source "net/Kconfig"
2017 source "drivers/Kconfig"
2019 source "drivers/firmware/Kconfig"
2023 source "arch/x86/Kconfig.debug"
2025 source "security/Kconfig"
2027 source "crypto/Kconfig"
2029 source "arch/x86/kvm/Kconfig"
2031 source "lib/Kconfig"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blob