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.
277 config NUMA_MIGRATE_IRQ_DESC
278 bool "Move irq desc when changing irq smp_affinity"
279 depends on SPARSE_IRQ && NUMA
283 This enables moving irq_desc to cpu/node that irq will use handled.
285 If you don't know what to do here, say N.
288 bool "Enable MPS table" if ACPI
290 depends on X86_LOCAL_APIC
292 For old smp systems that do not have proper acpi support. Newer systems
293 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
296 bool "Support for big SMP systems with more than 8 CPUs"
297 depends on X86_32 && SMP
299 This option is needed for the systems that have more than 8 CPUs
302 config X86_EXTENDED_PLATFORM
303 bool "Support for extended (non-PC) x86 platforms"
306 If you disable this option then the kernel will only support
307 standard PC platforms. (which covers the vast majority of
310 If you enable this option then you'll be able to select support
311 for the following (non-PC) 32 bit x86 platforms:
315 SGI 320/540 (Visual Workstation)
316 Summit/EXA (IBM x440)
317 Unisys ES7000 IA32 series
319 If you have one of these systems, or if you want to build a
320 generic distribution kernel, say Y here - otherwise say N.
324 config X86_EXTENDED_PLATFORM
325 bool "Support for extended (non-PC) x86 platforms"
328 If you disable this option then the kernel will only support
329 standard PC platforms. (which covers the vast majority of
332 If you enable this option then you'll be able to select support
333 for the following (non-PC) 64 bit x86 platforms:
337 If you have one of these systems, or if you want to build a
338 generic distribution kernel, say Y here - otherwise say N.
340 # This is an alphabetically sorted list of 64 bit extended platforms
341 # Please maintain the alphabetic order if and when there are additions
346 depends on X86_64 && PCI
347 depends on X86_EXTENDED_PLATFORM
349 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
350 supposed to run on these EM64T-based machines. Only choose this option
351 if you have one of these machines.
354 bool "SGI Ultraviolet"
356 depends on X86_EXTENDED_PLATFORM
360 This option is needed in order to support SGI Ultraviolet systems.
361 If you don't have one of these, you should say N here.
363 # Following is an alphabetically sorted list of 32 bit extended platforms
364 # Please maintain the alphabetic order if and when there are additions
369 depends on X86_EXTENDED_PLATFORM
371 Select this for an AMD Elan processor.
373 Do not use this option for K6/Athlon/Opteron processors!
375 If unsure, choose "PC-compatible" instead.
378 bool "RDC R-321x SoC"
380 depends on X86_EXTENDED_PLATFORM
382 select X86_REBOOTFIXUPS
384 This option is needed for RDC R-321x system-on-chip, also known
386 If you don't have one of these chips, you should say N here.
388 config X86_32_NON_STANDARD
389 bool "Support non-standard 32-bit SMP architectures"
390 depends on X86_32 && SMP
391 depends on X86_EXTENDED_PLATFORM
393 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
394 subarchitectures. It is intended for a generic binary kernel.
395 if you select them all, kernel will probe it one by one. and will
398 # Alphabetically sorted list of Non standard 32 bit platforms
401 bool "NUMAQ (IBM/Sequent)"
402 depends on X86_32_NON_STANDARD
406 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
407 NUMA multiquad box. This changes the way that processors are
408 bootstrapped, and uses Clustered Logical APIC addressing mode instead
409 of Flat Logical. You will need a new lynxer.elf file to flash your
410 firmware with - send email to <Martin.Bligh@us.ibm.com>.
413 bool "SGI 320/540 (Visual Workstation)"
414 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
415 depends on X86_32_NON_STANDARD
417 The SGI Visual Workstation series is an IA32-based workstation
418 based on SGI systems chips with some legacy PC hardware attached.
420 Say Y here to create a kernel to run on the SGI 320 or 540.
422 A kernel compiled for the Visual Workstation will run on general
423 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
426 bool "Summit/EXA (IBM x440)"
427 depends on X86_32_NON_STANDARD
429 This option is needed for IBM systems that use the Summit/EXA chipset.
430 In particular, it is needed for the x440.
433 bool "Unisys ES7000 IA32 series"
434 depends on X86_32_NON_STANDARD && X86_BIGSMP
436 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
437 supposed to run on an IA32-based Unisys ES7000 system.
439 config SCHED_OMIT_FRAME_POINTER
441 prompt "Single-depth WCHAN output"
444 Calculate simpler /proc/<PID>/wchan values. If this option
445 is disabled then wchan values will recurse back to the
446 caller function. This provides more accurate wchan values,
447 at the expense of slightly more scheduling overhead.
449 If in doubt, say "Y".
451 menuconfig PARAVIRT_GUEST
452 bool "Paravirtualized guest support"
454 Say Y here to get to see options related to running Linux under
455 various hypervisors. This option alone does not add any kernel code.
457 If you say N, all options in this submenu will be skipped and disabled.
461 source "arch/x86/xen/Kconfig"
464 bool "VMI Guest support"
468 VMI provides a paravirtualized interface to the VMware ESX server
469 (it could be used by other hypervisors in theory too, but is not
470 at the moment), by linking the kernel to a GPL-ed ROM module
471 provided by the hypervisor.
474 bool "KVM paravirtualized clock"
476 select PARAVIRT_CLOCK
478 Turning on this option will allow you to run a paravirtualized clock
479 when running over the KVM hypervisor. Instead of relying on a PIT
480 (or probably other) emulation by the underlying device model, the host
481 provides the guest with timing infrastructure such as time of day, and
485 bool "KVM Guest support"
488 This option enables various optimizations for running under the KVM
491 source "arch/x86/lguest/Kconfig"
494 bool "Enable paravirtualization code"
496 This changes the kernel so it can modify itself when it is run
497 under a hypervisor, potentially improving performance significantly
498 over full virtualization. However, when run without a hypervisor
499 the kernel is theoretically slower and slightly larger.
501 config PARAVIRT_SPINLOCKS
502 bool "Paravirtualization layer for spinlocks"
503 depends on PARAVIRT && SMP && EXPERIMENTAL
505 Paravirtualized spinlocks allow a pvops backend to replace the
506 spinlock implementation with something virtualization-friendly
507 (for example, block the virtual CPU rather than spinning).
509 Unfortunately the downside is an up to 5% performance hit on
510 native kernels, with various workloads.
512 If you are unsure how to answer this question, answer N.
514 config PARAVIRT_CLOCK
520 config PARAVIRT_DEBUG
521 bool "paravirt-ops debugging"
522 depends on PARAVIRT && DEBUG_KERNEL
524 Enable to debug paravirt_ops internals. Specifically, BUG if
525 a paravirt_op is missing when it is called.
530 This option adds a kernel parameter 'memtest', which allows memtest
532 memtest=0, mean disabled; -- default
533 memtest=1, mean do 1 test pattern;
535 memtest=4, mean do 4 test patterns.
536 If you are unsure how to answer this question, answer N.
538 config X86_SUMMIT_NUMA
540 depends on X86_32 && NUMA && X86_32_NON_STANDARD
542 config X86_CYCLONE_TIMER
544 depends on X86_32_NON_STANDARD
546 source "arch/x86/Kconfig.cpu"
550 prompt "HPET Timer Support" if X86_32
552 Use the IA-PC HPET (High Precision Event Timer) to manage
553 time in preference to the PIT and RTC, if a HPET is
555 HPET is the next generation timer replacing legacy 8254s.
556 The HPET provides a stable time base on SMP
557 systems, unlike the TSC, but it is more expensive to access,
558 as it is off-chip. You can find the HPET spec at
559 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
561 You can safely choose Y here. However, HPET will only be
562 activated if the platform and the BIOS support this feature.
563 Otherwise the 8254 will be used for timing services.
565 Choose N to continue using the legacy 8254 timer.
567 config HPET_EMULATE_RTC
569 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
571 # Mark as embedded because too many people got it wrong.
572 # The code disables itself when not needed.
575 bool "Enable DMI scanning" if EMBEDDED
577 Enabled scanning of DMI to identify machine quirks. Say Y
578 here unless you have verified that your setup is not
579 affected by entries in the DMI blacklist. Required by PNP
583 bool "GART IOMMU support" if EMBEDDED
587 depends on X86_64 && PCI
589 Support for full DMA access of devices with 32bit memory access only
590 on systems with more than 3GB. This is usually needed for USB,
591 sound, many IDE/SATA chipsets and some other devices.
592 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
593 based hardware IOMMU and a software bounce buffer based IOMMU used
594 on Intel systems and as fallback.
595 The code is only active when needed (enough memory and limited
596 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
600 bool "IBM Calgary IOMMU support"
602 depends on X86_64 && PCI && EXPERIMENTAL
604 Support for hardware IOMMUs in IBM's xSeries x366 and x460
605 systems. Needed to run systems with more than 3GB of memory
606 properly with 32-bit PCI devices that do not support DAC
607 (Double Address Cycle). Calgary also supports bus level
608 isolation, where all DMAs pass through the IOMMU. This
609 prevents them from going anywhere except their intended
610 destination. This catches hard-to-find kernel bugs and
611 mis-behaving drivers and devices that do not use the DMA-API
612 properly to set up their DMA buffers. The IOMMU can be
613 turned off at boot time with the iommu=off parameter.
614 Normally the kernel will make the right choice by itself.
617 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
619 prompt "Should Calgary be enabled by default?"
620 depends on CALGARY_IOMMU
622 Should Calgary be enabled by default? if you choose 'y', Calgary
623 will be used (if it exists). If you choose 'n', Calgary will not be
624 used even if it exists. If you choose 'n' and would like to use
625 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
629 bool "AMD IOMMU support"
632 depends on X86_64 && PCI && ACPI
634 With this option you can enable support for AMD IOMMU hardware in
635 your system. An IOMMU is a hardware component which provides
636 remapping of DMA memory accesses from devices. With an AMD IOMMU you
637 can isolate the the DMA memory of different devices and protect the
638 system from misbehaving device drivers or hardware.
640 You can find out if your system has an AMD IOMMU if you look into
641 your BIOS for an option to enable it or if you have an IVRS ACPI
644 config AMD_IOMMU_STATS
645 bool "Export AMD IOMMU statistics to debugfs"
649 This option enables code in the AMD IOMMU driver to collect various
650 statistics about whats happening in the driver and exports that
651 information to userspace via debugfs.
654 # need this always selected by IOMMU for the VIA workaround
658 Support for software bounce buffers used on x86-64 systems
659 which don't have a hardware IOMMU (e.g. the current generation
660 of Intel's x86-64 CPUs). Using this PCI devices which can only
661 access 32-bits of memory can be used on systems with more than
662 3 GB of memory. If unsure, say Y.
665 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
668 def_bool (AMD_IOMMU || DMAR)
671 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
672 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
673 select CPUMASK_OFFSTACK
676 Configure maximum number of CPUS and NUMA Nodes for this architecture.
680 int "Maximum number of CPUs" if SMP && !MAXSMP
681 range 2 8 if SMP && X86_32 && !X86_BIGSMP
682 range 2 512 if SMP && !MAXSMP
684 default "4096" if MAXSMP
685 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
688 This allows you to specify the maximum number of CPUs which this
689 kernel will support. The maximum supported value is 512 and the
690 minimum value which makes sense is 2.
692 This is purely to save memory - each supported CPU adds
693 approximately eight kilobytes to the kernel image.
696 bool "SMT (Hyperthreading) scheduler support"
699 SMT scheduler support improves the CPU scheduler's decision making
700 when dealing with Intel Pentium 4 chips with HyperThreading at a
701 cost of slightly increased overhead in some places. If unsure say
706 prompt "Multi-core scheduler support"
709 Multi-core scheduler support improves the CPU scheduler's decision
710 making when dealing with multi-core CPU chips at a cost of slightly
711 increased overhead in some places. If unsure say N here.
713 source "kernel/Kconfig.preempt"
716 bool "Local APIC support on uniprocessors"
717 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
719 A local APIC (Advanced Programmable Interrupt Controller) is an
720 integrated interrupt controller in the CPU. If you have a single-CPU
721 system which has a processor with a local APIC, you can say Y here to
722 enable and use it. If you say Y here even though your machine doesn't
723 have a local APIC, then the kernel will still run with no slowdown at
724 all. The local APIC supports CPU-generated self-interrupts (timer,
725 performance counters), and the NMI watchdog which detects hard
729 bool "IO-APIC support on uniprocessors"
730 depends on X86_UP_APIC
732 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
733 SMP-capable replacement for PC-style interrupt controllers. Most
734 SMP systems and many recent uniprocessor systems have one.
736 If you have a single-CPU system with an IO-APIC, you can say Y here
737 to use it. If you say Y here even though your machine doesn't have
738 an IO-APIC, then the kernel will still run with no slowdown at all.
740 config X86_LOCAL_APIC
742 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
746 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
748 config X86_VISWS_APIC
750 depends on X86_32 && X86_VISWS
752 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
753 bool "Reroute for broken boot IRQs"
755 depends on X86_IO_APIC
757 This option enables a workaround that fixes a source of
758 spurious interrupts. This is recommended when threaded
759 interrupt handling is used on systems where the generation of
760 superfluous "boot interrupts" cannot be disabled.
762 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
763 entry in the chipset's IO-APIC is masked (as, e.g. the RT
764 kernel does during interrupt handling). On chipsets where this
765 boot IRQ generation cannot be disabled, this workaround keeps
766 the original IRQ line masked so that only the equivalent "boot
767 IRQ" is delivered to the CPUs. The workaround also tells the
768 kernel to set up the IRQ handler on the boot IRQ line. In this
769 way only one interrupt is delivered to the kernel. Otherwise
770 the spurious second interrupt may cause the kernel to bring
771 down (vital) interrupt lines.
773 Only affects "broken" chipsets. Interrupt sharing may be
774 increased on these systems.
777 bool "Machine Check Exception"
779 Machine Check Exception support allows the processor to notify the
780 kernel if it detects a problem (e.g. overheating, component failure).
781 The action the kernel takes depends on the severity of the problem,
782 ranging from a warning message on the console, to halting the machine.
783 Your processor must be a Pentium or newer to support this - check the
784 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
785 have a design flaw which leads to false MCE events - hence MCE is
786 disabled on all P5 processors, unless explicitly enabled with "mce"
787 as a boot argument. Similarly, if MCE is built in and creates a
788 problem on some new non-standard machine, you can boot with "nomce"
789 to disable it. MCE support simply ignores non-MCE processors like
790 the 386 and 486, so nearly everyone can say Y here.
793 depends on X86_32 && X86_MCE
794 bool "Use legacy machine check code (will go away)"
796 select X86_ANCIENT_MCE
798 Use the old i386 machine check code. This is merely intended for
799 testing in a transition period. Try this if you run into any machine
800 check related software problems, but report the problem to
801 linux-kernel. When in doubt say no.
806 default y if (!X86_OLD_MCE && X86_32) || X86_64
810 prompt "Intel MCE features"
811 depends on X86_NEW_MCE && X86_LOCAL_APIC
813 Additional support for intel specific MCE features such as
818 prompt "AMD MCE features"
819 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
821 Additional support for AMD specific MCE features such as
822 the DRAM Error Threshold.
824 config X86_ANCIENT_MCE
827 prompt "Support for old Pentium 5 / WinChip machine checks"
829 Include support for machine check handling on old Pentium 5 or WinChip
830 systems. These typically need to be enabled explicitely on the command
833 config X86_MCE_THRESHOLD
834 depends on X86_MCE_AMD || X86_MCE_INTEL
838 config X86_MCE_NONFATAL
839 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
840 depends on X86_OLD_MCE
842 Enabling this feature starts a timer that triggers every 5 seconds which
843 will look at the machine check registers to see if anything happened.
844 Non-fatal problems automatically get corrected (but still logged).
845 Disable this if you don't want to see these messages.
846 Seeing the messages this option prints out may be indicative of dying
847 or out-of-spec (ie, overclocked) hardware.
848 This option only does something on certain CPUs.
849 (AMD Athlon/Duron and Intel Pentium 4)
851 config X86_MCE_P4THERMAL
852 bool "check for P4 thermal throttling interrupt."
853 depends on X86_OLD_MCE && X86_MCE && (X86_UP_APIC || SMP)
855 Enabling this feature will cause a message to be printed when the P4
856 enters thermal throttling.
858 config X86_THERMAL_VECTOR
860 depends on X86_MCE_P4THERMAL || X86_MCE_INTEL
863 bool "Enable VM86 support" if EMBEDDED
867 This option is required by programs like DOSEMU to run 16-bit legacy
868 code on X86 processors. It also may be needed by software like
869 XFree86 to initialize some video cards via BIOS. Disabling this
870 option saves about 6k.
873 tristate "Toshiba Laptop support"
876 This adds a driver to safely access the System Management Mode of
877 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
878 not work on models with a Phoenix BIOS. The System Management Mode
879 is used to set the BIOS and power saving options on Toshiba portables.
881 For information on utilities to make use of this driver see the
882 Toshiba Linux utilities web site at:
883 <http://www.buzzard.org.uk/toshiba/>.
885 Say Y if you intend to run this kernel on a Toshiba portable.
889 tristate "Dell laptop support"
891 This adds a driver to safely access the System Management Mode
892 of the CPU on the Dell Inspiron 8000. The System Management Mode
893 is used to read cpu temperature and cooling fan status and to
894 control the fans on the I8K portables.
896 This driver has been tested only on the Inspiron 8000 but it may
897 also work with other Dell laptops. You can force loading on other
898 models by passing the parameter `force=1' to the module. Use at
901 For information on utilities to make use of this driver see the
902 I8K Linux utilities web site at:
903 <http://people.debian.org/~dz/i8k/>
905 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
908 config X86_REBOOTFIXUPS
909 bool "Enable X86 board specific fixups for reboot"
912 This enables chipset and/or board specific fixups to be done
913 in order to get reboot to work correctly. This is only needed on
914 some combinations of hardware and BIOS. The symptom, for which
915 this config is intended, is when reboot ends with a stalled/hung
918 Currently, the only fixup is for the Geode machines using
919 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
921 Say Y if you want to enable the fixup. Currently, it's safe to
922 enable this option even if you don't need it.
926 tristate "/dev/cpu/microcode - microcode support"
929 If you say Y here, you will be able to update the microcode on
930 certain Intel and AMD processors. The Intel support is for the
931 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
932 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
933 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
934 You will obviously need the actual microcode binary data itself
935 which is not shipped with the Linux kernel.
937 This option selects the general module only, you need to select
938 at least one vendor specific module as well.
940 To compile this driver as a module, choose M here: the
941 module will be called microcode.
943 config MICROCODE_INTEL
944 bool "Intel microcode patch loading support"
949 This options enables microcode patch loading support for Intel
952 For latest news and information on obtaining all the required
953 Intel ingredients for this driver, check:
954 <http://www.urbanmyth.org/microcode/>.
957 bool "AMD microcode patch loading support"
961 If you select this option, microcode patch loading support for AMD
962 processors will be enabled.
964 config MICROCODE_OLD_INTERFACE
969 tristate "/dev/cpu/*/msr - Model-specific register support"
971 This device gives privileged processes access to the x86
972 Model-Specific Registers (MSRs). It is a character device with
973 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
974 MSR accesses are directed to a specific CPU on multi-processor
978 tristate "/dev/cpu/*/cpuid - CPU information support"
980 This device gives processes access to the x86 CPUID instruction to
981 be executed on a specific processor. It is a character device
982 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
986 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
988 If you select this option, this will provide various x86 CPUs
989 information through debugfs.
992 prompt "High Memory Support"
993 default HIGHMEM4G if !X86_NUMAQ
994 default HIGHMEM64G if X86_NUMAQ
999 depends on !X86_NUMAQ
1001 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1002 However, the address space of 32-bit x86 processors is only 4
1003 Gigabytes large. That means that, if you have a large amount of
1004 physical memory, not all of it can be "permanently mapped" by the
1005 kernel. The physical memory that's not permanently mapped is called
1008 If you are compiling a kernel which will never run on a machine with
1009 more than 1 Gigabyte total physical RAM, answer "off" here (default
1010 choice and suitable for most users). This will result in a "3GB/1GB"
1011 split: 3GB are mapped so that each process sees a 3GB virtual memory
1012 space and the remaining part of the 4GB virtual memory space is used
1013 by the kernel to permanently map as much physical memory as
1016 If the machine has between 1 and 4 Gigabytes physical RAM, then
1019 If more than 4 Gigabytes is used then answer "64GB" here. This
1020 selection turns Intel PAE (Physical Address Extension) mode on.
1021 PAE implements 3-level paging on IA32 processors. PAE is fully
1022 supported by Linux, PAE mode is implemented on all recent Intel
1023 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1024 then the kernel will not boot on CPUs that don't support PAE!
1026 The actual amount of total physical memory will either be
1027 auto detected or can be forced by using a kernel command line option
1028 such as "mem=256M". (Try "man bootparam" or see the documentation of
1029 your boot loader (lilo or loadlin) about how to pass options to the
1030 kernel at boot time.)
1032 If unsure, say "off".
1036 depends on !X86_NUMAQ
1038 Select this if you have a 32-bit processor and between 1 and 4
1039 gigabytes of physical RAM.
1043 depends on !M386 && !M486
1046 Select this if you have a 32-bit processor and more than 4
1047 gigabytes of physical RAM.
1052 depends on EXPERIMENTAL
1053 prompt "Memory split" if EMBEDDED
1057 Select the desired split between kernel and user memory.
1059 If the address range available to the kernel is less than the
1060 physical memory installed, the remaining memory will be available
1061 as "high memory". Accessing high memory is a little more costly
1062 than low memory, as it needs to be mapped into the kernel first.
1063 Note that increasing the kernel address space limits the range
1064 available to user programs, making the address space there
1065 tighter. Selecting anything other than the default 3G/1G split
1066 will also likely make your kernel incompatible with binary-only
1069 If you are not absolutely sure what you are doing, leave this
1073 bool "3G/1G user/kernel split"
1074 config VMSPLIT_3G_OPT
1076 bool "3G/1G user/kernel split (for full 1G low memory)"
1078 bool "2G/2G user/kernel split"
1079 config VMSPLIT_2G_OPT
1081 bool "2G/2G user/kernel split (for full 2G low memory)"
1083 bool "1G/3G user/kernel split"
1088 default 0xB0000000 if VMSPLIT_3G_OPT
1089 default 0x80000000 if VMSPLIT_2G
1090 default 0x78000000 if VMSPLIT_2G_OPT
1091 default 0x40000000 if VMSPLIT_1G
1097 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1100 bool "PAE (Physical Address Extension) Support"
1101 depends on X86_32 && !HIGHMEM4G
1103 PAE is required for NX support, and furthermore enables
1104 larger swapspace support for non-overcommit purposes. It
1105 has the cost of more pagetable lookup overhead, and also
1106 consumes more pagetable space per process.
1108 config ARCH_PHYS_ADDR_T_64BIT
1109 def_bool X86_64 || X86_PAE
1111 config DIRECT_GBPAGES
1112 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1116 Allow the kernel linear mapping to use 1GB pages on CPUs that
1117 support it. This can improve the kernel's performance a tiny bit by
1118 reducing TLB pressure. If in doubt, say "Y".
1120 # Common NUMA Features
1122 bool "Numa Memory Allocation and Scheduler Support"
1124 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1125 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1127 Enable NUMA (Non Uniform Memory Access) support.
1129 The kernel will try to allocate memory used by a CPU on the
1130 local memory controller of the CPU and add some more
1131 NUMA awareness to the kernel.
1133 For 64-bit this is recommended if the system is Intel Core i7
1134 (or later), AMD Opteron, or EM64T NUMA.
1136 For 32-bit this is only needed on (rare) 32-bit-only platforms
1137 that support NUMA topologies, such as NUMAQ / Summit, or if you
1138 boot a 32-bit kernel on a 64-bit NUMA platform.
1140 Otherwise, you should say N.
1142 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1143 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1147 prompt "Old style AMD Opteron NUMA detection"
1148 depends on X86_64 && NUMA && PCI
1150 Enable K8 NUMA node topology detection. You should say Y here if
1151 you have a multi processor AMD K8 system. This uses an old
1152 method to read the NUMA configuration directly from the builtin
1153 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1154 instead, which also takes priority if both are compiled in.
1156 config X86_64_ACPI_NUMA
1158 prompt "ACPI NUMA detection"
1159 depends on X86_64 && NUMA && ACPI && PCI
1162 Enable ACPI SRAT based node topology detection.
1164 # Some NUMA nodes have memory ranges that span
1165 # other nodes. Even though a pfn is valid and
1166 # between a node's start and end pfns, it may not
1167 # reside on that node. See memmap_init_zone()
1169 config NODES_SPAN_OTHER_NODES
1171 depends on X86_64_ACPI_NUMA
1174 bool "NUMA emulation"
1175 depends on X86_64 && NUMA
1177 Enable NUMA emulation. A flat machine will be split
1178 into virtual nodes when booted with "numa=fake=N", where N is the
1179 number of nodes. This is only useful for debugging.
1182 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1184 default "9" if MAXSMP
1185 default "6" if X86_64
1186 default "4" if X86_NUMAQ
1188 depends on NEED_MULTIPLE_NODES
1190 Specify the maximum number of NUMA Nodes available on the target
1191 system. Increases memory reserved to accommodate various tables.
1193 config HAVE_ARCH_BOOTMEM
1195 depends on X86_32 && NUMA
1197 config ARCH_HAVE_MEMORY_PRESENT
1199 depends on X86_32 && DISCONTIGMEM
1201 config NEED_NODE_MEMMAP_SIZE
1203 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1205 config HAVE_ARCH_ALLOC_REMAP
1207 depends on X86_32 && NUMA
1209 config ARCH_FLATMEM_ENABLE
1211 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1213 config ARCH_DISCONTIGMEM_ENABLE
1215 depends on NUMA && X86_32
1217 config ARCH_DISCONTIGMEM_DEFAULT
1219 depends on NUMA && X86_32
1221 config ARCH_SPARSEMEM_DEFAULT
1225 config ARCH_SPARSEMEM_ENABLE
1227 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1228 select SPARSEMEM_STATIC if X86_32
1229 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1231 config ARCH_SELECT_MEMORY_MODEL
1233 depends on ARCH_SPARSEMEM_ENABLE
1235 config ARCH_MEMORY_PROBE
1237 depends on MEMORY_HOTPLUG
1242 bool "Allocate 3rd-level pagetables from highmem"
1243 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1245 The VM uses one page table entry for each page of physical memory.
1246 For systems with a lot of RAM, this can be wasteful of precious
1247 low memory. Setting this option will put user-space page table
1248 entries in high memory.
1250 config X86_CHECK_BIOS_CORRUPTION
1251 bool "Check for low memory corruption"
1253 Periodically check for memory corruption in low memory, which
1254 is suspected to be caused by BIOS. Even when enabled in the
1255 configuration, it is disabled at runtime. Enable it by
1256 setting "memory_corruption_check=1" on the kernel command
1257 line. By default it scans the low 64k of memory every 60
1258 seconds; see the memory_corruption_check_size and
1259 memory_corruption_check_period parameters in
1260 Documentation/kernel-parameters.txt to adjust this.
1262 When enabled with the default parameters, this option has
1263 almost no overhead, as it reserves a relatively small amount
1264 of memory and scans it infrequently. It both detects corruption
1265 and prevents it from affecting the running system.
1267 It is, however, intended as a diagnostic tool; if repeatable
1268 BIOS-originated corruption always affects the same memory,
1269 you can use memmap= to prevent the kernel from using that
1272 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1273 bool "Set the default setting of memory_corruption_check"
1274 depends on X86_CHECK_BIOS_CORRUPTION
1277 Set whether the default state of memory_corruption_check is
1280 config X86_RESERVE_LOW_64K
1281 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1284 Reserve the first 64K of physical RAM on BIOSes that are known
1285 to potentially corrupt that memory range. A numbers of BIOSes are
1286 known to utilize this area during suspend/resume, so it must not
1287 be used by the kernel.
1289 Set this to N if you are absolutely sure that you trust the BIOS
1290 to get all its memory reservations and usages right.
1292 If you have doubts about the BIOS (e.g. suspend/resume does not
1293 work or there's kernel crashes after certain hardware hotplug
1294 events) and it's not AMI or Phoenix, then you might want to enable
1295 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1296 corruption patterns.
1300 config MATH_EMULATION
1302 prompt "Math emulation" if X86_32
1304 Linux can emulate a math coprocessor (used for floating point
1305 operations) if you don't have one. 486DX and Pentium processors have
1306 a math coprocessor built in, 486SX and 386 do not, unless you added
1307 a 487DX or 387, respectively. (The messages during boot time can
1308 give you some hints here ["man dmesg"].) Everyone needs either a
1309 coprocessor or this emulation.
1311 If you don't have a math coprocessor, you need to say Y here; if you
1312 say Y here even though you have a coprocessor, the coprocessor will
1313 be used nevertheless. (This behavior can be changed with the kernel
1314 command line option "no387", which comes handy if your coprocessor
1315 is broken. Try "man bootparam" or see the documentation of your boot
1316 loader (lilo or loadlin) about how to pass options to the kernel at
1317 boot time.) This means that it is a good idea to say Y here if you
1318 intend to use this kernel on different machines.
1320 More information about the internals of the Linux math coprocessor
1321 emulation can be found in <file:arch/x86/math-emu/README>.
1323 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1324 kernel, it won't hurt.
1327 bool "MTRR (Memory Type Range Register) support"
1329 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1330 the Memory Type Range Registers (MTRRs) may be used to control
1331 processor access to memory ranges. This is most useful if you have
1332 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1333 allows bus write transfers to be combined into a larger transfer
1334 before bursting over the PCI/AGP bus. This can increase performance
1335 of image write operations 2.5 times or more. Saying Y here creates a
1336 /proc/mtrr file which may be used to manipulate your processor's
1337 MTRRs. Typically the X server should use this.
1339 This code has a reasonably generic interface so that similar
1340 control registers on other processors can be easily supported
1343 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1344 Registers (ARRs) which provide a similar functionality to MTRRs. For
1345 these, the ARRs are used to emulate the MTRRs.
1346 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1347 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1348 write-combining. All of these processors are supported by this code
1349 and it makes sense to say Y here if you have one of them.
1351 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1352 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1353 can lead to all sorts of problems, so it's good to say Y here.
1355 You can safely say Y even if your machine doesn't have MTRRs, you'll
1356 just add about 9 KB to your kernel.
1358 See <file:Documentation/x86/mtrr.txt> for more information.
1360 config MTRR_SANITIZER
1362 prompt "MTRR cleanup support"
1365 Convert MTRR layout from continuous to discrete, so X drivers can
1366 add writeback entries.
1368 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1369 The largest mtrr entry size for a continuous block can be set with
1374 config MTRR_SANITIZER_ENABLE_DEFAULT
1375 int "MTRR cleanup enable value (0-1)"
1378 depends on MTRR_SANITIZER
1380 Enable mtrr cleanup default value
1382 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1383 int "MTRR cleanup spare reg num (0-7)"
1386 depends on MTRR_SANITIZER
1388 mtrr cleanup spare entries default, it can be changed via
1389 mtrr_spare_reg_nr=N on the kernel command line.
1393 prompt "x86 PAT support"
1396 Use PAT attributes to setup page level cache control.
1398 PATs are the modern equivalents of MTRRs and are much more
1399 flexible than MTRRs.
1401 Say N here if you see bootup problems (boot crash, boot hang,
1402 spontaneous reboots) or a non-working video driver.
1407 bool "EFI runtime service support"
1410 This enables the kernel to use EFI runtime services that are
1411 available (such as the EFI variable services).
1413 This option is only useful on systems that have EFI firmware.
1414 In addition, you should use the latest ELILO loader available
1415 at <http://elilo.sourceforge.net> in order to take advantage
1416 of EFI runtime services. However, even with this option, the
1417 resultant kernel should continue to boot on existing non-EFI
1422 prompt "Enable seccomp to safely compute untrusted bytecode"
1424 This kernel feature is useful for number crunching applications
1425 that may need to compute untrusted bytecode during their
1426 execution. By using pipes or other transports made available to
1427 the process as file descriptors supporting the read/write
1428 syscalls, it's possible to isolate those applications in
1429 their own address space using seccomp. Once seccomp is
1430 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1431 and the task is only allowed to execute a few safe syscalls
1432 defined by each seccomp mode.
1434 If unsure, say Y. Only embedded should say N here.
1436 config CC_STACKPROTECTOR_ALL
1439 config CC_STACKPROTECTOR
1440 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1441 select CC_STACKPROTECTOR_ALL
1443 This option turns on the -fstack-protector GCC feature. This
1444 feature puts, at the beginning of functions, a canary value on
1445 the stack just before the return address, and validates
1446 the value just before actually returning. Stack based buffer
1447 overflows (that need to overwrite this return address) now also
1448 overwrite the canary, which gets detected and the attack is then
1449 neutralized via a kernel panic.
1451 This feature requires gcc version 4.2 or above, or a distribution
1452 gcc with the feature backported. Older versions are automatically
1453 detected and for those versions, this configuration option is
1454 ignored. (and a warning is printed during bootup)
1456 source kernel/Kconfig.hz
1459 bool "kexec system call"
1461 kexec is a system call that implements the ability to shutdown your
1462 current kernel, and to start another kernel. It is like a reboot
1463 but it is independent of the system firmware. And like a reboot
1464 you can start any kernel with it, not just Linux.
1466 The name comes from the similarity to the exec system call.
1468 It is an ongoing process to be certain the hardware in a machine
1469 is properly shutdown, so do not be surprised if this code does not
1470 initially work for you. It may help to enable device hotplugging
1471 support. As of this writing the exact hardware interface is
1472 strongly in flux, so no good recommendation can be made.
1475 bool "kernel crash dumps"
1476 depends on X86_64 || (X86_32 && HIGHMEM)
1478 Generate crash dump after being started by kexec.
1479 This should be normally only set in special crash dump kernels
1480 which are loaded in the main kernel with kexec-tools into
1481 a specially reserved region and then later executed after
1482 a crash by kdump/kexec. The crash dump kernel must be compiled
1483 to a memory address not used by the main kernel or BIOS using
1484 PHYSICAL_START, or it must be built as a relocatable image
1485 (CONFIG_RELOCATABLE=y).
1486 For more details see Documentation/kdump/kdump.txt
1489 bool "kexec jump (EXPERIMENTAL)"
1490 depends on EXPERIMENTAL
1491 depends on KEXEC && HIBERNATION
1493 Jump between original kernel and kexeced kernel and invoke
1494 code in physical address mode via KEXEC
1496 config PHYSICAL_START
1497 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1498 default "0x1000000" if X86_NUMAQ
1499 default "0x200000" if X86_64
1502 This gives the physical address where the kernel is loaded.
1504 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1505 bzImage will decompress itself to above physical address and
1506 run from there. Otherwise, bzImage will run from the address where
1507 it has been loaded by the boot loader and will ignore above physical
1510 In normal kdump cases one does not have to set/change this option
1511 as now bzImage can be compiled as a completely relocatable image
1512 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1513 address. This option is mainly useful for the folks who don't want
1514 to use a bzImage for capturing the crash dump and want to use a
1515 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1516 to be specifically compiled to run from a specific memory area
1517 (normally a reserved region) and this option comes handy.
1519 So if you are using bzImage for capturing the crash dump, leave
1520 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1521 Otherwise if you plan to use vmlinux for capturing the crash dump
1522 change this value to start of the reserved region (Typically 16MB
1523 0x1000000). In other words, it can be set based on the "X" value as
1524 specified in the "crashkernel=YM@XM" command line boot parameter
1525 passed to the panic-ed kernel. Typically this parameter is set as
1526 crashkernel=64M@16M. Please take a look at
1527 Documentation/kdump/kdump.txt for more details about crash dumps.
1529 Usage of bzImage for capturing the crash dump is recommended as
1530 one does not have to build two kernels. Same kernel can be used
1531 as production kernel and capture kernel. Above option should have
1532 gone away after relocatable bzImage support is introduced. But it
1533 is present because there are users out there who continue to use
1534 vmlinux for dump capture. This option should go away down the
1537 Don't change this unless you know what you are doing.
1540 bool "Build a relocatable kernel (EXPERIMENTAL)"
1541 depends on EXPERIMENTAL
1543 This builds a kernel image that retains relocation information
1544 so it can be loaded someplace besides the default 1MB.
1545 The relocations tend to make the kernel binary about 10% larger,
1546 but are discarded at runtime.
1548 One use is for the kexec on panic case where the recovery kernel
1549 must live at a different physical address than the primary
1552 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1553 it has been loaded at and the compile time physical address
1554 (CONFIG_PHYSICAL_START) is ignored.
1556 config PHYSICAL_ALIGN
1558 prompt "Alignment value to which kernel should be aligned" if X86_32
1559 default "0x100000" if X86_32
1560 default "0x200000" if X86_64
1561 range 0x2000 0x400000
1563 This value puts the alignment restrictions on physical address
1564 where kernel is loaded and run from. Kernel is compiled for an
1565 address which meets above alignment restriction.
1567 If bootloader loads the kernel at a non-aligned address and
1568 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1569 address aligned to above value and run from there.
1571 If bootloader loads the kernel at a non-aligned address and
1572 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1573 load address and decompress itself to the address it has been
1574 compiled for and run from there. The address for which kernel is
1575 compiled already meets above alignment restrictions. Hence the
1576 end result is that kernel runs from a physical address meeting
1577 above alignment restrictions.
1579 Don't change this unless you know what you are doing.
1582 bool "Support for hot-pluggable CPUs"
1583 depends on SMP && HOTPLUG
1585 Say Y here to allow turning CPUs off and on. CPUs can be
1586 controlled through /sys/devices/system/cpu.
1587 ( Note: power management support will enable this option
1588 automatically on SMP systems. )
1589 Say N if you want to disable CPU hotplug.
1593 prompt "Compat VDSO support"
1594 depends on X86_32 || IA32_EMULATION
1596 Map the 32-bit VDSO to the predictable old-style address too.
1598 Say N here if you are running a sufficiently recent glibc
1599 version (2.3.3 or later), to remove the high-mapped
1600 VDSO mapping and to exclusively use the randomized VDSO.
1605 bool "Built-in kernel command line"
1608 Allow for specifying boot arguments to the kernel at
1609 build time. On some systems (e.g. embedded ones), it is
1610 necessary or convenient to provide some or all of the
1611 kernel boot arguments with the kernel itself (that is,
1612 to not rely on the boot loader to provide them.)
1614 To compile command line arguments into the kernel,
1615 set this option to 'Y', then fill in the
1616 the boot arguments in CONFIG_CMDLINE.
1618 Systems with fully functional boot loaders (i.e. non-embedded)
1619 should leave this option set to 'N'.
1622 string "Built-in kernel command string"
1623 depends on CMDLINE_BOOL
1626 Enter arguments here that should be compiled into the kernel
1627 image and used at boot time. If the boot loader provides a
1628 command line at boot time, it is appended to this string to
1629 form the full kernel command line, when the system boots.
1631 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1632 change this behavior.
1634 In most cases, the command line (whether built-in or provided
1635 by the boot loader) should specify the device for the root
1638 config CMDLINE_OVERRIDE
1639 bool "Built-in command line overrides boot loader arguments"
1641 depends on CMDLINE_BOOL
1643 Set this option to 'Y' to have the kernel ignore the boot loader
1644 command line, and use ONLY the built-in command line.
1646 This is used to work around broken boot loaders. This should
1647 be set to 'N' under normal conditions.
1651 config ARCH_ENABLE_MEMORY_HOTPLUG
1653 depends on X86_64 || (X86_32 && HIGHMEM)
1655 config ARCH_ENABLE_MEMORY_HOTREMOVE
1657 depends on MEMORY_HOTPLUG
1659 config HAVE_ARCH_EARLY_PFN_TO_NID
1663 menu "Power management and ACPI options"
1665 config ARCH_HIBERNATION_HEADER
1667 depends on X86_64 && HIBERNATION
1669 source "kernel/power/Kconfig"
1671 source "drivers/acpi/Kconfig"
1676 depends on APM || APM_MODULE
1679 tristate "APM (Advanced Power Management) BIOS support"
1680 depends on X86_32 && PM_SLEEP
1682 APM is a BIOS specification for saving power using several different
1683 techniques. This is mostly useful for battery powered laptops with
1684 APM compliant BIOSes. If you say Y here, the system time will be
1685 reset after a RESUME operation, the /proc/apm device will provide
1686 battery status information, and user-space programs will receive
1687 notification of APM "events" (e.g. battery status change).
1689 If you select "Y" here, you can disable actual use of the APM
1690 BIOS by passing the "apm=off" option to the kernel at boot time.
1692 Note that the APM support is almost completely disabled for
1693 machines with more than one CPU.
1695 In order to use APM, you will need supporting software. For location
1696 and more information, read <file:Documentation/power/pm.txt> and the
1697 Battery Powered Linux mini-HOWTO, available from
1698 <http://www.tldp.org/docs.html#howto>.
1700 This driver does not spin down disk drives (see the hdparm(8)
1701 manpage ("man 8 hdparm") for that), and it doesn't turn off
1702 VESA-compliant "green" monitors.
1704 This driver does not support the TI 4000M TravelMate and the ACER
1705 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1706 desktop machines also don't have compliant BIOSes, and this driver
1707 may cause those machines to panic during the boot phase.
1709 Generally, if you don't have a battery in your machine, there isn't
1710 much point in using this driver and you should say N. If you get
1711 random kernel OOPSes or reboots that don't seem to be related to
1712 anything, try disabling/enabling this option (or disabling/enabling
1715 Some other things you should try when experiencing seemingly random,
1718 1) make sure that you have enough swap space and that it is
1720 2) pass the "no-hlt" option to the kernel
1721 3) switch on floating point emulation in the kernel and pass
1722 the "no387" option to the kernel
1723 4) pass the "floppy=nodma" option to the kernel
1724 5) pass the "mem=4M" option to the kernel (thereby disabling
1725 all but the first 4 MB of RAM)
1726 6) make sure that the CPU is not over clocked.
1727 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1728 8) disable the cache from your BIOS settings
1729 9) install a fan for the video card or exchange video RAM
1730 10) install a better fan for the CPU
1731 11) exchange RAM chips
1732 12) exchange the motherboard.
1734 To compile this driver as a module, choose M here: the
1735 module will be called apm.
1739 config APM_IGNORE_USER_SUSPEND
1740 bool "Ignore USER SUSPEND"
1742 This option will ignore USER SUSPEND requests. On machines with a
1743 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1744 series notebooks, it is necessary to say Y because of a BIOS bug.
1746 config APM_DO_ENABLE
1747 bool "Enable PM at boot time"
1749 Enable APM features at boot time. From page 36 of the APM BIOS
1750 specification: "When disabled, the APM BIOS does not automatically
1751 power manage devices, enter the Standby State, enter the Suspend
1752 State, or take power saving steps in response to CPU Idle calls."
1753 This driver will make CPU Idle calls when Linux is idle (unless this
1754 feature is turned off -- see "Do CPU IDLE calls", below). This
1755 should always save battery power, but more complicated APM features
1756 will be dependent on your BIOS implementation. You may need to turn
1757 this option off if your computer hangs at boot time when using APM
1758 support, or if it beeps continuously instead of suspending. Turn
1759 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1760 T400CDT. This is off by default since most machines do fine without
1764 bool "Make CPU Idle calls when idle"
1766 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1767 On some machines, this can activate improved power savings, such as
1768 a slowed CPU clock rate, when the machine is idle. These idle calls
1769 are made after the idle loop has run for some length of time (e.g.,
1770 333 mS). On some machines, this will cause a hang at boot time or
1771 whenever the CPU becomes idle. (On machines with more than one CPU,
1772 this option does nothing.)
1774 config APM_DISPLAY_BLANK
1775 bool "Enable console blanking using APM"
1777 Enable console blanking using the APM. Some laptops can use this to
1778 turn off the LCD backlight when the screen blanker of the Linux
1779 virtual console blanks the screen. Note that this is only used by
1780 the virtual console screen blanker, and won't turn off the backlight
1781 when using the X Window system. This also doesn't have anything to
1782 do with your VESA-compliant power-saving monitor. Further, this
1783 option doesn't work for all laptops -- it might not turn off your
1784 backlight at all, or it might print a lot of errors to the console,
1785 especially if you are using gpm.
1787 config APM_ALLOW_INTS
1788 bool "Allow interrupts during APM BIOS calls"
1790 Normally we disable external interrupts while we are making calls to
1791 the APM BIOS as a measure to lessen the effects of a badly behaving
1792 BIOS implementation. The BIOS should reenable interrupts if it
1793 needs to. Unfortunately, some BIOSes do not -- especially those in
1794 many of the newer IBM Thinkpads. If you experience hangs when you
1795 suspend, try setting this to Y. Otherwise, say N.
1799 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1801 source "drivers/cpuidle/Kconfig"
1803 source "drivers/idle/Kconfig"
1808 menu "Bus options (PCI etc.)"
1813 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1815 Find out whether you have a PCI motherboard. PCI is the name of a
1816 bus system, i.e. the way the CPU talks to the other stuff inside
1817 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1818 VESA. If you have PCI, say Y, otherwise N.
1821 prompt "PCI access mode"
1822 depends on X86_32 && PCI
1825 On PCI systems, the BIOS can be used to detect the PCI devices and
1826 determine their configuration. However, some old PCI motherboards
1827 have BIOS bugs and may crash if this is done. Also, some embedded
1828 PCI-based systems don't have any BIOS at all. Linux can also try to
1829 detect the PCI hardware directly without using the BIOS.
1831 With this option, you can specify how Linux should detect the
1832 PCI devices. If you choose "BIOS", the BIOS will be used,
1833 if you choose "Direct", the BIOS won't be used, and if you
1834 choose "MMConfig", then PCI Express MMCONFIG will be used.
1835 If you choose "Any", the kernel will try MMCONFIG, then the
1836 direct access method and falls back to the BIOS if that doesn't
1837 work. If unsure, go with the default, which is "Any".
1842 config PCI_GOMMCONFIG
1859 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1861 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1864 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1868 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1872 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1879 bool "Support mmconfig PCI config space access"
1880 depends on X86_64 && PCI && ACPI
1883 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1884 depends on PCI_MSI && ACPI && EXPERIMENTAL
1886 DMA remapping (DMAR) devices support enables independent address
1887 translations for Direct Memory Access (DMA) from devices.
1888 These DMA remapping devices are reported via ACPI tables
1889 and include PCI device scope covered by these DMA
1892 config DMAR_DEFAULT_ON
1894 prompt "Enable DMA Remapping Devices by default"
1897 Selecting this option will enable a DMAR device at boot time if
1898 one is found. If this option is not selected, DMAR support can
1899 be enabled by passing intel_iommu=on to the kernel. It is
1900 recommended you say N here while the DMAR code remains
1905 prompt "Support for Graphics workaround"
1908 Current Graphics drivers tend to use physical address
1909 for DMA and avoid using DMA APIs. Setting this config
1910 option permits the IOMMU driver to set a unity map for
1911 all the OS-visible memory. Hence the driver can continue
1912 to use physical addresses for DMA.
1914 config DMAR_FLOPPY_WA
1918 Floppy disk drivers are know to bypass DMA API calls
1919 thereby failing to work when IOMMU is enabled. This
1920 workaround will setup a 1:1 mapping for the first
1921 16M to make floppy (an ISA device) work.
1924 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1925 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1927 Supports Interrupt remapping for IO-APIC and MSI devices.
1928 To use x2apic mode in the CPU's which support x2APIC enhancements or
1929 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1931 source "drivers/pci/pcie/Kconfig"
1933 source "drivers/pci/Kconfig"
1935 # x86_64 have no ISA slots, but do have ISA-style DMA.
1944 Find out whether you have ISA slots on your motherboard. ISA is the
1945 name of a bus system, i.e. the way the CPU talks to the other stuff
1946 inside your box. Other bus systems are PCI, EISA, MicroChannel
1947 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1948 newer boards don't support it. If you have ISA, say Y, otherwise N.
1954 The Extended Industry Standard Architecture (EISA) bus was
1955 developed as an open alternative to the IBM MicroChannel bus.
1957 The EISA bus provided some of the features of the IBM MicroChannel
1958 bus while maintaining backward compatibility with cards made for
1959 the older ISA bus. The EISA bus saw limited use between 1988 and
1960 1995 when it was made obsolete by the PCI bus.
1962 Say Y here if you are building a kernel for an EISA-based machine.
1966 source "drivers/eisa/Kconfig"
1971 MicroChannel Architecture is found in some IBM PS/2 machines and
1972 laptops. It is a bus system similar to PCI or ISA. See
1973 <file:Documentation/mca.txt> (and especially the web page given
1974 there) before attempting to build an MCA bus kernel.
1976 source "drivers/mca/Kconfig"
1979 tristate "NatSemi SCx200 support"
1981 This provides basic support for National Semiconductor's
1982 (now AMD's) Geode processors. The driver probes for the
1983 PCI-IDs of several on-chip devices, so its a good dependency
1984 for other scx200_* drivers.
1986 If compiled as a module, the driver is named scx200.
1988 config SCx200HR_TIMER
1989 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1990 depends on SCx200 && GENERIC_TIME
1993 This driver provides a clocksource built upon the on-chip
1994 27MHz high-resolution timer. Its also a workaround for
1995 NSC Geode SC-1100's buggy TSC, which loses time when the
1996 processor goes idle (as is done by the scheduler). The
1997 other workaround is idle=poll boot option.
1999 config GEODE_MFGPT_TIMER
2001 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2002 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2004 This driver provides a clock event source based on the MFGPT
2005 timer(s) in the CS5535 and CS5536 companion chip for the geode.
2006 MFGPTs have a better resolution and max interval than the
2007 generic PIT, and are suitable for use as high-res timers.
2010 bool "One Laptop Per Child support"
2013 Add support for detecting the unique features of the OLPC
2020 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2022 source "drivers/pcmcia/Kconfig"
2024 source "drivers/pci/hotplug/Kconfig"
2029 menu "Executable file formats / Emulations"
2031 source "fs/Kconfig.binfmt"
2033 config IA32_EMULATION
2034 bool "IA32 Emulation"
2036 select COMPAT_BINFMT_ELF
2038 Include code to run 32-bit programs under a 64-bit kernel. You should
2039 likely turn this on, unless you're 100% sure that you don't have any
2040 32-bit programs left.
2043 tristate "IA32 a.out support"
2044 depends on IA32_EMULATION
2046 Support old a.out binaries in the 32bit emulation.
2050 depends on IA32_EMULATION
2052 config COMPAT_FOR_U64_ALIGNMENT
2056 config SYSVIPC_COMPAT
2058 depends on COMPAT && SYSVIPC
2063 config HAVE_ATOMIC_IOMAP
2067 source "net/Kconfig"
2069 source "drivers/Kconfig"
2071 source "drivers/firmware/Kconfig"
2075 source "arch/x86/Kconfig.debug"
2077 source "security/Kconfig"
2079 source "crypto/Kconfig"
2081 source "arch/x86/kvm/Kconfig"
2083 source "lib/Kconfig"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blob