2 mainmenu "Linux Kernel Configuration for x86"
6 bool "64-bit kernel" if ARCH = "x86"
7 default ARCH = "x86_64"
9 Say yes to build a 64-bit kernel - formerly known as x86_64
10 Say no to build a 32-bit kernel - formerly known as i386
21 select HAVE_AOUT if X86_32
24 select HAVE_UNSTABLE_SCHED_CLOCK
27 select HAVE_IOREMAP_PROT
29 select ARCH_WANT_OPTIONAL_GPIOLIB
30 select ARCH_WANT_FRAME_POINTERS
31 select HAVE_KRETPROBES
32 select HAVE_FTRACE_MCOUNT_RECORD
33 select HAVE_DYNAMIC_FTRACE
34 select HAVE_FUNCTION_TRACER
35 select HAVE_FUNCTION_GRAPH_TRACER
36 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
39 select HAVE_ARCH_TRACEHOOK
40 select HAVE_GENERIC_DMA_COHERENT if X86_32
41 select HAVE_EFFICIENT_UNALIGNED_ACCESS
42 select USER_STACKTRACE_SUPPORT
46 default "arch/x86/configs/i386_defconfig" if X86_32
47 default "arch/x86/configs/x86_64_defconfig" if X86_64
52 config GENERIC_CMOS_UPDATE
55 config CLOCKSOURCE_WATCHDOG
58 config GENERIC_CLOCKEVENTS
61 config GENERIC_CLOCKEVENTS_BROADCAST
63 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
65 config LOCKDEP_SUPPORT
68 config STACKTRACE_SUPPORT
71 config HAVE_LATENCYTOP_SUPPORT
74 config FAST_CMPXCHG_LOCAL
87 config GENERIC_ISA_DMA
96 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
98 config GENERIC_BUG_RELATIVE_POINTERS
101 config GENERIC_HWEIGHT
107 config ARCH_MAY_HAVE_PC_FDC
110 config RWSEM_GENERIC_SPINLOCK
113 config RWSEM_XCHGADD_ALGORITHM
116 config ARCH_HAS_CPU_IDLE_WAIT
119 config GENERIC_CALIBRATE_DELAY
122 config GENERIC_TIME_VSYSCALL
126 config ARCH_HAS_CPU_RELAX
129 config ARCH_HAS_DEFAULT_IDLE
132 config ARCH_HAS_CACHE_LINE_SIZE
135 config HAVE_SETUP_PER_CPU_AREA
138 config HAVE_CPUMASK_OF_CPU_MAP
141 config ARCH_HIBERNATION_POSSIBLE
144 config ARCH_SUSPEND_POSSIBLE
151 config ARCH_POPULATES_NODE_MAP
158 config ARCH_SUPPORTS_OPTIMIZED_INLINING
161 # Use the generic interrupt handling code in kernel/irq/:
162 config GENERIC_HARDIRQS
166 config GENERIC_IRQ_PROBE
170 config GENERIC_PENDING_IRQ
172 depends on GENERIC_HARDIRQS && SMP
175 config USE_GENERIC_SMP_HELPERS
181 depends on X86_32 && SMP
185 depends on X86_64 && SMP
192 config X86_TRAMPOLINE
194 depends on SMP || (64BIT && ACPI_SLEEP)
197 config X86_32_LAZY_GS
199 depends on X86_32 && !CC_STACKPROTECTOR
203 source "init/Kconfig"
204 source "kernel/Kconfig.freezer"
206 menu "Processor type and features"
208 source "kernel/time/Kconfig"
211 bool "Symmetric multi-processing support"
213 This enables support for systems with more than one CPU. If you have
214 a system with only one CPU, like most personal computers, say N. If
215 you have a system with more than one CPU, say Y.
217 If you say N here, the kernel will run on single and multiprocessor
218 machines, but will use only one CPU of a multiprocessor machine. If
219 you say Y here, the kernel will run on many, but not all,
220 singleprocessor machines. On a singleprocessor machine, the kernel
221 will run faster if you say N here.
223 Note that if you say Y here and choose architecture "586" or
224 "Pentium" under "Processor family", the kernel will not work on 486
225 architectures. Similarly, multiprocessor kernels for the "PPro"
226 architecture may not work on all Pentium based boards.
228 People using multiprocessor machines who say Y here should also say
229 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
230 Management" code will be disabled if you say Y here.
232 See also <file:Documentation/i386/IO-APIC.txt>,
233 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
234 <http://www.tldp.org/docs.html#howto>.
236 If you don't know what to do here, say N.
239 bool "Support x2apic"
240 depends on X86_LOCAL_APIC && X86_64
242 This enables x2apic support on CPUs that have this feature.
244 This allows 32-bit apic IDs (so it can support very large systems),
245 and accesses the local apic via MSRs not via mmio.
247 ( On certain CPU models you may need to enable INTR_REMAP too,
248 to get functional x2apic mode. )
250 If you don't know what to do here, say N.
253 bool "Support sparse irq numbering"
254 depends on PCI_MSI || HT_IRQ
256 This enables support for sparse irqs. This is useful for distro
257 kernels that want to define a high CONFIG_NR_CPUS value but still
258 want to have low kernel memory footprint on smaller machines.
260 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
261 out the irq_desc[] array in a more NUMA-friendly way. )
263 If you don't know what to do here, say N.
265 config NUMA_MIGRATE_IRQ_DESC
266 bool "Move irq desc when changing irq smp_affinity"
267 depends on SPARSE_IRQ && NUMA
270 This enables moving irq_desc to cpu/node that irq will use handled.
272 If you don't know what to do here, say N.
275 bool "Enable MPS table" if ACPI
277 depends on X86_LOCAL_APIC
279 For old smp systems that do not have proper acpi support. Newer systems
280 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
283 bool "Support for big SMP systems with more than 8 CPUs"
284 depends on X86_32 && SMP
286 This option is needed for the systems that have more than 8 CPUs
289 config X86_EXTENDED_PLATFORM
290 bool "Support for extended (non-PC) x86 platforms"
293 If you disable this option then the kernel will only support
294 standard PC platforms. (which covers the vast majority of
297 If you enable this option then you'll be able to select support
298 for the following (non-PC) 32 bit x86 platforms:
302 SGI 320/540 (Visual Workstation)
303 Summit/EXA (IBM x440)
304 Unisys ES7000 IA32 series
306 If you have one of these systems, or if you want to build a
307 generic distribution kernel, say Y here - otherwise say N.
311 config X86_EXTENDED_PLATFORM
312 bool "Support for extended (non-PC) x86 platforms"
315 If you disable this option then the kernel will only support
316 standard PC platforms. (which covers the vast majority of
319 If you enable this option then you'll be able to select support
320 for the following (non-PC) 64 bit x86 platforms:
324 If you have one of these systems, or if you want to build a
325 generic distribution kernel, say Y here - otherwise say N.
327 # This is an alphabetically sorted list of 64 bit extended platforms
328 # Please maintain the alphabetic order if and when there are additions
333 depends on X86_64 && PCI
334 depends on X86_EXTENDED_PLATFORM
336 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
337 supposed to run on these EM64T-based machines. Only choose this option
338 if you have one of these machines.
341 bool "SGI Ultraviolet"
343 depends on X86_EXTENDED_PLATFORM
346 This option is needed in order to support SGI Ultraviolet systems.
347 If you don't have one of these, you should say N here.
349 # Following is an alphabetically sorted list of 32 bit extended platforms
350 # Please maintain the alphabetic order if and when there are additions
355 depends on X86_EXTENDED_PLATFORM
357 Select this for an AMD Elan processor.
359 Do not use this option for K6/Athlon/Opteron processors!
361 If unsure, choose "PC-compatible" instead.
364 bool "RDC R-321x SoC"
366 depends on X86_EXTENDED_PLATFORM
368 select X86_REBOOTFIXUPS
370 This option is needed for RDC R-321x system-on-chip, also known
372 If you don't have one of these chips, you should say N here.
374 config X86_32_NON_STANDARD
375 bool "Support non-standard 32-bit SMP architectures"
376 depends on X86_32 && SMP
377 depends on X86_EXTENDED_PLATFORM
379 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
380 subarchitectures. It is intended for a generic binary kernel.
381 if you select them all, kernel will probe it one by one. and will
384 # Alphabetically sorted list of Non standard 32 bit platforms
387 bool "NUMAQ (IBM/Sequent)"
388 depends on X86_32_NON_STANDARD
392 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
393 NUMA multiquad box. This changes the way that processors are
394 bootstrapped, and uses Clustered Logical APIC addressing mode instead
395 of Flat Logical. You will need a new lynxer.elf file to flash your
396 firmware with - send email to <Martin.Bligh@us.ibm.com>.
399 bool "SGI 320/540 (Visual Workstation)"
400 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
401 depends on X86_32_NON_STANDARD
403 The SGI Visual Workstation series is an IA32-based workstation
404 based on SGI systems chips with some legacy PC hardware attached.
406 Say Y here to create a kernel to run on the SGI 320 or 540.
408 A kernel compiled for the Visual Workstation will run on general
409 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
412 bool "Summit/EXA (IBM x440)"
413 depends on X86_32_NON_STANDARD
415 This option is needed for IBM systems that use the Summit/EXA chipset.
416 In particular, it is needed for the x440.
419 bool "Unisys ES7000 IA32 series"
420 depends on X86_32_NON_STANDARD && X86_BIGSMP
422 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
423 supposed to run on an IA32-based Unisys ES7000 system.
425 config SCHED_OMIT_FRAME_POINTER
427 prompt "Single-depth WCHAN output"
430 Calculate simpler /proc/<PID>/wchan values. If this option
431 is disabled then wchan values will recurse back to the
432 caller function. This provides more accurate wchan values,
433 at the expense of slightly more scheduling overhead.
435 If in doubt, say "Y".
437 menuconfig PARAVIRT_GUEST
438 bool "Paravirtualized guest support"
440 Say Y here to get to see options related to running Linux under
441 various hypervisors. This option alone does not add any kernel code.
443 If you say N, all options in this submenu will be skipped and disabled.
447 source "arch/x86/xen/Kconfig"
450 bool "VMI Guest support"
454 VMI provides a paravirtualized interface to the VMware ESX server
455 (it could be used by other hypervisors in theory too, but is not
456 at the moment), by linking the kernel to a GPL-ed ROM module
457 provided by the hypervisor.
460 bool "KVM paravirtualized clock"
462 select PARAVIRT_CLOCK
464 Turning on this option will allow you to run a paravirtualized clock
465 when running over the KVM hypervisor. Instead of relying on a PIT
466 (or probably other) emulation by the underlying device model, the host
467 provides the guest with timing infrastructure such as time of day, and
471 bool "KVM Guest support"
474 This option enables various optimizations for running under the KVM
477 source "arch/x86/lguest/Kconfig"
480 bool "Enable paravirtualization code"
482 This changes the kernel so it can modify itself when it is run
483 under a hypervisor, potentially improving performance significantly
484 over full virtualization. However, when run without a hypervisor
485 the kernel is theoretically slower and slightly larger.
487 config PARAVIRT_CLOCK
493 config PARAVIRT_DEBUG
494 bool "paravirt-ops debugging"
495 depends on PARAVIRT && DEBUG_KERNEL
497 Enable to debug paravirt_ops internals. Specifically, BUG if
498 a paravirt_op is missing when it is called.
503 This option adds a kernel parameter 'memtest', which allows memtest
505 memtest=0, mean disabled; -- default
506 memtest=1, mean do 1 test pattern;
508 memtest=4, mean do 4 test patterns.
509 If you are unsure how to answer this question, answer N.
511 config X86_SUMMIT_NUMA
513 depends on X86_32 && NUMA && X86_32_NON_STANDARD
515 config X86_CYCLONE_TIMER
517 depends on X86_32_NON_STANDARD
519 source "arch/x86/Kconfig.cpu"
523 prompt "HPET Timer Support" if X86_32
525 Use the IA-PC HPET (High Precision Event Timer) to manage
526 time in preference to the PIT and RTC, if a HPET is
528 HPET is the next generation timer replacing legacy 8254s.
529 The HPET provides a stable time base on SMP
530 systems, unlike the TSC, but it is more expensive to access,
531 as it is off-chip. You can find the HPET spec at
532 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
534 You can safely choose Y here. However, HPET will only be
535 activated if the platform and the BIOS support this feature.
536 Otherwise the 8254 will be used for timing services.
538 Choose N to continue using the legacy 8254 timer.
540 config HPET_EMULATE_RTC
542 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
544 # Mark as embedded because too many people got it wrong.
545 # The code disables itself when not needed.
548 bool "Enable DMI scanning" if EMBEDDED
550 Enabled scanning of DMI to identify machine quirks. Say Y
551 here unless you have verified that your setup is not
552 affected by entries in the DMI blacklist. Required by PNP
556 bool "GART IOMMU support" if EMBEDDED
560 depends on X86_64 && PCI
562 Support for full DMA access of devices with 32bit memory access only
563 on systems with more than 3GB. This is usually needed for USB,
564 sound, many IDE/SATA chipsets and some other devices.
565 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
566 based hardware IOMMU and a software bounce buffer based IOMMU used
567 on Intel systems and as fallback.
568 The code is only active when needed (enough memory and limited
569 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
573 bool "IBM Calgary IOMMU support"
575 depends on X86_64 && PCI && EXPERIMENTAL
577 Support for hardware IOMMUs in IBM's xSeries x366 and x460
578 systems. Needed to run systems with more than 3GB of memory
579 properly with 32-bit PCI devices that do not support DAC
580 (Double Address Cycle). Calgary also supports bus level
581 isolation, where all DMAs pass through the IOMMU. This
582 prevents them from going anywhere except their intended
583 destination. This catches hard-to-find kernel bugs and
584 mis-behaving drivers and devices that do not use the DMA-API
585 properly to set up their DMA buffers. The IOMMU can be
586 turned off at boot time with the iommu=off parameter.
587 Normally the kernel will make the right choice by itself.
590 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
592 prompt "Should Calgary be enabled by default?"
593 depends on CALGARY_IOMMU
595 Should Calgary be enabled by default? if you choose 'y', Calgary
596 will be used (if it exists). If you choose 'n', Calgary will not be
597 used even if it exists. If you choose 'n' and would like to use
598 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
602 bool "AMD IOMMU support"
605 depends on X86_64 && PCI && ACPI
607 With this option you can enable support for AMD IOMMU hardware in
608 your system. An IOMMU is a hardware component which provides
609 remapping of DMA memory accesses from devices. With an AMD IOMMU you
610 can isolate the the DMA memory of different devices and protect the
611 system from misbehaving device drivers or hardware.
613 You can find out if your system has an AMD IOMMU if you look into
614 your BIOS for an option to enable it or if you have an IVRS ACPI
617 config AMD_IOMMU_STATS
618 bool "Export AMD IOMMU statistics to debugfs"
622 This option enables code in the AMD IOMMU driver to collect various
623 statistics about whats happening in the driver and exports that
624 information to userspace via debugfs.
627 # need this always selected by IOMMU for the VIA workaround
631 Support for software bounce buffers used on x86-64 systems
632 which don't have a hardware IOMMU (e.g. the current generation
633 of Intel's x86-64 CPUs). Using this PCI devices which can only
634 access 32-bits of memory can be used on systems with more than
635 3 GB of memory. If unsure, say Y.
638 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
641 def_bool (AMD_IOMMU || DMAR)
644 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
645 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
646 select CPUMASK_OFFSTACK
649 Configure maximum number of CPUS and NUMA Nodes for this architecture.
653 int "Maximum number of CPUs" if SMP && !MAXSMP
654 range 2 512 if SMP && !MAXSMP
656 default "4096" if MAXSMP
657 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
660 This allows you to specify the maximum number of CPUs which this
661 kernel will support. The maximum supported value is 512 and the
662 minimum value which makes sense is 2.
664 This is purely to save memory - each supported CPU adds
665 approximately eight kilobytes to the kernel image.
668 bool "SMT (Hyperthreading) scheduler support"
671 SMT scheduler support improves the CPU scheduler's decision making
672 when dealing with Intel Pentium 4 chips with HyperThreading at a
673 cost of slightly increased overhead in some places. If unsure say
678 prompt "Multi-core scheduler support"
681 Multi-core scheduler support improves the CPU scheduler's decision
682 making when dealing with multi-core CPU chips at a cost of slightly
683 increased overhead in some places. If unsure say N here.
685 source "kernel/Kconfig.preempt"
688 bool "Local APIC support on uniprocessors"
689 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
691 A local APIC (Advanced Programmable Interrupt Controller) is an
692 integrated interrupt controller in the CPU. If you have a single-CPU
693 system which has a processor with a local APIC, you can say Y here to
694 enable and use it. If you say Y here even though your machine doesn't
695 have a local APIC, then the kernel will still run with no slowdown at
696 all. The local APIC supports CPU-generated self-interrupts (timer,
697 performance counters), and the NMI watchdog which detects hard
701 bool "IO-APIC support on uniprocessors"
702 depends on X86_UP_APIC
704 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
705 SMP-capable replacement for PC-style interrupt controllers. Most
706 SMP systems and many recent uniprocessor systems have one.
708 If you have a single-CPU system with an IO-APIC, you can say Y here
709 to use it. If you say Y here even though your machine doesn't have
710 an IO-APIC, then the kernel will still run with no slowdown at all.
712 config X86_LOCAL_APIC
714 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
715 select HAVE_PERF_COUNTERS if (!M386 && !M486)
719 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
721 config X86_VISWS_APIC
723 depends on X86_32 && X86_VISWS
725 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
726 bool "Reroute for broken boot IRQs"
728 depends on X86_IO_APIC
730 This option enables a workaround that fixes a source of
731 spurious interrupts. This is recommended when threaded
732 interrupt handling is used on systems where the generation of
733 superfluous "boot interrupts" cannot be disabled.
735 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
736 entry in the chipset's IO-APIC is masked (as, e.g. the RT
737 kernel does during interrupt handling). On chipsets where this
738 boot IRQ generation cannot be disabled, this workaround keeps
739 the original IRQ line masked so that only the equivalent "boot
740 IRQ" is delivered to the CPUs. The workaround also tells the
741 kernel to set up the IRQ handler on the boot IRQ line. In this
742 way only one interrupt is delivered to the kernel. Otherwise
743 the spurious second interrupt may cause the kernel to bring
744 down (vital) interrupt lines.
746 Only affects "broken" chipsets. Interrupt sharing may be
747 increased on these systems.
750 bool "Machine Check Exception"
752 Machine Check Exception support allows the processor to notify the
753 kernel if it detects a problem (e.g. overheating, component failure).
754 The action the kernel takes depends on the severity of the problem,
755 ranging from a warning message on the console, to halting the machine.
756 Your processor must be a Pentium or newer to support this - check the
757 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
758 have a design flaw which leads to false MCE events - hence MCE is
759 disabled on all P5 processors, unless explicitly enabled with "mce"
760 as a boot argument. Similarly, if MCE is built in and creates a
761 problem on some new non-standard machine, you can boot with "nomce"
762 to disable it. MCE support simply ignores non-MCE processors like
763 the 386 and 486, so nearly everyone can say Y here.
767 prompt "Intel MCE features"
768 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
770 Additional support for intel specific MCE features such as
775 prompt "AMD MCE features"
776 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
778 Additional support for AMD specific MCE features such as
779 the DRAM Error Threshold.
781 config X86_MCE_NONFATAL
782 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
783 depends on X86_32 && X86_MCE
785 Enabling this feature starts a timer that triggers every 5 seconds which
786 will look at the machine check registers to see if anything happened.
787 Non-fatal problems automatically get corrected (but still logged).
788 Disable this if you don't want to see these messages.
789 Seeing the messages this option prints out may be indicative of dying
790 or out-of-spec (ie, overclocked) hardware.
791 This option only does something on certain CPUs.
792 (AMD Athlon/Duron and Intel Pentium 4)
794 config X86_MCE_P4THERMAL
795 bool "check for P4 thermal throttling interrupt."
796 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
798 Enabling this feature will cause a message to be printed when the P4
799 enters thermal throttling.
802 bool "Enable VM86 support" if EMBEDDED
806 This option is required by programs like DOSEMU to run 16-bit legacy
807 code on X86 processors. It also may be needed by software like
808 XFree86 to initialize some video cards via BIOS. Disabling this
809 option saves about 6k.
812 tristate "Toshiba Laptop support"
815 This adds a driver to safely access the System Management Mode of
816 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
817 not work on models with a Phoenix BIOS. The System Management Mode
818 is used to set the BIOS and power saving options on Toshiba portables.
820 For information on utilities to make use of this driver see the
821 Toshiba Linux utilities web site at:
822 <http://www.buzzard.org.uk/toshiba/>.
824 Say Y if you intend to run this kernel on a Toshiba portable.
828 tristate "Dell laptop support"
830 This adds a driver to safely access the System Management Mode
831 of the CPU on the Dell Inspiron 8000. The System Management Mode
832 is used to read cpu temperature and cooling fan status and to
833 control the fans on the I8K portables.
835 This driver has been tested only on the Inspiron 8000 but it may
836 also work with other Dell laptops. You can force loading on other
837 models by passing the parameter `force=1' to the module. Use at
840 For information on utilities to make use of this driver see the
841 I8K Linux utilities web site at:
842 <http://people.debian.org/~dz/i8k/>
844 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
847 config X86_REBOOTFIXUPS
848 bool "Enable X86 board specific fixups for reboot"
851 This enables chipset and/or board specific fixups to be done
852 in order to get reboot to work correctly. This is only needed on
853 some combinations of hardware and BIOS. The symptom, for which
854 this config is intended, is when reboot ends with a stalled/hung
857 Currently, the only fixup is for the Geode machines using
858 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
860 Say Y if you want to enable the fixup. Currently, it's safe to
861 enable this option even if you don't need it.
865 tristate "/dev/cpu/microcode - microcode support"
868 If you say Y here, you will be able to update the microcode on
869 certain Intel and AMD processors. The Intel support is for the
870 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
871 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
872 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
873 You will obviously need the actual microcode binary data itself
874 which is not shipped with the Linux kernel.
876 This option selects the general module only, you need to select
877 at least one vendor specific module as well.
879 To compile this driver as a module, choose M here: the
880 module will be called microcode.
882 config MICROCODE_INTEL
883 bool "Intel microcode patch loading support"
888 This options enables microcode patch loading support for Intel
891 For latest news and information on obtaining all the required
892 Intel ingredients for this driver, check:
893 <http://www.urbanmyth.org/microcode/>.
896 bool "AMD microcode patch loading support"
900 If you select this option, microcode patch loading support for AMD
901 processors will be enabled.
903 config MICROCODE_OLD_INTERFACE
908 tristate "/dev/cpu/*/msr - Model-specific register support"
910 This device gives privileged processes access to the x86
911 Model-Specific Registers (MSRs). It is a character device with
912 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
913 MSR accesses are directed to a specific CPU on multi-processor
917 tristate "/dev/cpu/*/cpuid - CPU information support"
919 This device gives processes access to the x86 CPUID instruction to
920 be executed on a specific processor. It is a character device
921 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
925 prompt "High Memory Support"
926 default HIGHMEM4G if !X86_NUMAQ
927 default HIGHMEM64G if X86_NUMAQ
932 depends on !X86_NUMAQ
934 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
935 However, the address space of 32-bit x86 processors is only 4
936 Gigabytes large. That means that, if you have a large amount of
937 physical memory, not all of it can be "permanently mapped" by the
938 kernel. The physical memory that's not permanently mapped is called
941 If you are compiling a kernel which will never run on a machine with
942 more than 1 Gigabyte total physical RAM, answer "off" here (default
943 choice and suitable for most users). This will result in a "3GB/1GB"
944 split: 3GB are mapped so that each process sees a 3GB virtual memory
945 space and the remaining part of the 4GB virtual memory space is used
946 by the kernel to permanently map as much physical memory as
949 If the machine has between 1 and 4 Gigabytes physical RAM, then
952 If more than 4 Gigabytes is used then answer "64GB" here. This
953 selection turns Intel PAE (Physical Address Extension) mode on.
954 PAE implements 3-level paging on IA32 processors. PAE is fully
955 supported by Linux, PAE mode is implemented on all recent Intel
956 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
957 then the kernel will not boot on CPUs that don't support PAE!
959 The actual amount of total physical memory will either be
960 auto detected or can be forced by using a kernel command line option
961 such as "mem=256M". (Try "man bootparam" or see the documentation of
962 your boot loader (lilo or loadlin) about how to pass options to the
963 kernel at boot time.)
965 If unsure, say "off".
969 depends on !X86_NUMAQ
971 Select this if you have a 32-bit processor and between 1 and 4
972 gigabytes of physical RAM.
976 depends on !M386 && !M486
979 Select this if you have a 32-bit processor and more than 4
980 gigabytes of physical RAM.
985 depends on EXPERIMENTAL
986 prompt "Memory split" if EMBEDDED
990 Select the desired split between kernel and user memory.
992 If the address range available to the kernel is less than the
993 physical memory installed, the remaining memory will be available
994 as "high memory". Accessing high memory is a little more costly
995 than low memory, as it needs to be mapped into the kernel first.
996 Note that increasing the kernel address space limits the range
997 available to user programs, making the address space there
998 tighter. Selecting anything other than the default 3G/1G split
999 will also likely make your kernel incompatible with binary-only
1002 If you are not absolutely sure what you are doing, leave this
1006 bool "3G/1G user/kernel split"
1007 config VMSPLIT_3G_OPT
1009 bool "3G/1G user/kernel split (for full 1G low memory)"
1011 bool "2G/2G user/kernel split"
1012 config VMSPLIT_2G_OPT
1014 bool "2G/2G user/kernel split (for full 2G low memory)"
1016 bool "1G/3G user/kernel split"
1021 default 0xB0000000 if VMSPLIT_3G_OPT
1022 default 0x80000000 if VMSPLIT_2G
1023 default 0x78000000 if VMSPLIT_2G_OPT
1024 default 0x40000000 if VMSPLIT_1G
1030 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1033 bool "PAE (Physical Address Extension) Support"
1034 depends on X86_32 && !HIGHMEM4G
1036 PAE is required for NX support, and furthermore enables
1037 larger swapspace support for non-overcommit purposes. It
1038 has the cost of more pagetable lookup overhead, and also
1039 consumes more pagetable space per process.
1041 config ARCH_PHYS_ADDR_T_64BIT
1042 def_bool X86_64 || X86_PAE
1044 config DIRECT_GBPAGES
1045 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1049 Allow the kernel linear mapping to use 1GB pages on CPUs that
1050 support it. This can improve the kernel's performance a tiny bit by
1051 reducing TLB pressure. If in doubt, say "Y".
1053 # Common NUMA Features
1055 bool "Numa Memory Allocation and Scheduler Support"
1057 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1058 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1060 Enable NUMA (Non Uniform Memory Access) support.
1062 The kernel will try to allocate memory used by a CPU on the
1063 local memory controller of the CPU and add some more
1064 NUMA awareness to the kernel.
1066 For 64-bit this is recommended if the system is Intel Core i7
1067 (or later), AMD Opteron, or EM64T NUMA.
1069 For 32-bit this is only needed on (rare) 32-bit-only platforms
1070 that support NUMA topologies, such as NUMAQ / Summit, or if you
1071 boot a 32-bit kernel on a 64-bit NUMA platform.
1073 Otherwise, you should say N.
1075 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1076 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1080 prompt "Old style AMD Opteron NUMA detection"
1081 depends on X86_64 && NUMA && PCI
1083 Enable K8 NUMA node topology detection. You should say Y here if
1084 you have a multi processor AMD K8 system. This uses an old
1085 method to read the NUMA configuration directly from the builtin
1086 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1087 instead, which also takes priority if both are compiled in.
1089 config X86_64_ACPI_NUMA
1091 prompt "ACPI NUMA detection"
1092 depends on X86_64 && NUMA && ACPI && PCI
1095 Enable ACPI SRAT based node topology detection.
1097 # Some NUMA nodes have memory ranges that span
1098 # other nodes. Even though a pfn is valid and
1099 # between a node's start and end pfns, it may not
1100 # reside on that node. See memmap_init_zone()
1102 config NODES_SPAN_OTHER_NODES
1104 depends on X86_64_ACPI_NUMA
1107 bool "NUMA emulation"
1108 depends on X86_64 && NUMA
1110 Enable NUMA emulation. A flat machine will be split
1111 into virtual nodes when booted with "numa=fake=N", where N is the
1112 number of nodes. This is only useful for debugging.
1115 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1117 default "9" if MAXSMP
1118 default "6" if X86_64
1119 default "4" if X86_NUMAQ
1121 depends on NEED_MULTIPLE_NODES
1123 Specify the maximum number of NUMA Nodes available on the target
1124 system. Increases memory reserved to accomodate various tables.
1126 config HAVE_ARCH_BOOTMEM_NODE
1128 depends on X86_32 && NUMA
1130 config ARCH_HAVE_MEMORY_PRESENT
1132 depends on X86_32 && DISCONTIGMEM
1134 config NEED_NODE_MEMMAP_SIZE
1136 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1138 config HAVE_ARCH_ALLOC_REMAP
1140 depends on X86_32 && NUMA
1142 config ARCH_FLATMEM_ENABLE
1144 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1146 config ARCH_DISCONTIGMEM_ENABLE
1148 depends on NUMA && X86_32
1150 config ARCH_DISCONTIGMEM_DEFAULT
1152 depends on NUMA && X86_32
1154 config ARCH_SPARSEMEM_DEFAULT
1158 config ARCH_SPARSEMEM_ENABLE
1160 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1161 select SPARSEMEM_STATIC if X86_32
1162 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1164 config ARCH_SELECT_MEMORY_MODEL
1166 depends on ARCH_SPARSEMEM_ENABLE
1168 config ARCH_MEMORY_PROBE
1170 depends on MEMORY_HOTPLUG
1175 bool "Allocate 3rd-level pagetables from highmem"
1176 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1178 The VM uses one page table entry for each page of physical memory.
1179 For systems with a lot of RAM, this can be wasteful of precious
1180 low memory. Setting this option will put user-space page table
1181 entries in high memory.
1183 config X86_CHECK_BIOS_CORRUPTION
1184 bool "Check for low memory corruption"
1186 Periodically check for memory corruption in low memory, which
1187 is suspected to be caused by BIOS. Even when enabled in the
1188 configuration, it is disabled at runtime. Enable it by
1189 setting "memory_corruption_check=1" on the kernel command
1190 line. By default it scans the low 64k of memory every 60
1191 seconds; see the memory_corruption_check_size and
1192 memory_corruption_check_period parameters in
1193 Documentation/kernel-parameters.txt to adjust this.
1195 When enabled with the default parameters, this option has
1196 almost no overhead, as it reserves a relatively small amount
1197 of memory and scans it infrequently. It both detects corruption
1198 and prevents it from affecting the running system.
1200 It is, however, intended as a diagnostic tool; if repeatable
1201 BIOS-originated corruption always affects the same memory,
1202 you can use memmap= to prevent the kernel from using that
1205 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1206 bool "Set the default setting of memory_corruption_check"
1207 depends on X86_CHECK_BIOS_CORRUPTION
1210 Set whether the default state of memory_corruption_check is
1213 config X86_RESERVE_LOW_64K
1214 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1217 Reserve the first 64K of physical RAM on BIOSes that are known
1218 to potentially corrupt that memory range. A numbers of BIOSes are
1219 known to utilize this area during suspend/resume, so it must not
1220 be used by the kernel.
1222 Set this to N if you are absolutely sure that you trust the BIOS
1223 to get all its memory reservations and usages right.
1225 If you have doubts about the BIOS (e.g. suspend/resume does not
1226 work or there's kernel crashes after certain hardware hotplug
1227 events) and it's not AMI or Phoenix, then you might want to enable
1228 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1229 corruption patterns.
1233 config MATH_EMULATION
1235 prompt "Math emulation" if X86_32
1237 Linux can emulate a math coprocessor (used for floating point
1238 operations) if you don't have one. 486DX and Pentium processors have
1239 a math coprocessor built in, 486SX and 386 do not, unless you added
1240 a 487DX or 387, respectively. (The messages during boot time can
1241 give you some hints here ["man dmesg"].) Everyone needs either a
1242 coprocessor or this emulation.
1244 If you don't have a math coprocessor, you need to say Y here; if you
1245 say Y here even though you have a coprocessor, the coprocessor will
1246 be used nevertheless. (This behavior can be changed with the kernel
1247 command line option "no387", which comes handy if your coprocessor
1248 is broken. Try "man bootparam" or see the documentation of your boot
1249 loader (lilo or loadlin) about how to pass options to the kernel at
1250 boot time.) This means that it is a good idea to say Y here if you
1251 intend to use this kernel on different machines.
1253 More information about the internals of the Linux math coprocessor
1254 emulation can be found in <file:arch/x86/math-emu/README>.
1256 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1257 kernel, it won't hurt.
1260 bool "MTRR (Memory Type Range Register) support"
1262 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1263 the Memory Type Range Registers (MTRRs) may be used to control
1264 processor access to memory ranges. This is most useful if you have
1265 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1266 allows bus write transfers to be combined into a larger transfer
1267 before bursting over the PCI/AGP bus. This can increase performance
1268 of image write operations 2.5 times or more. Saying Y here creates a
1269 /proc/mtrr file which may be used to manipulate your processor's
1270 MTRRs. Typically the X server should use this.
1272 This code has a reasonably generic interface so that similar
1273 control registers on other processors can be easily supported
1276 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1277 Registers (ARRs) which provide a similar functionality to MTRRs. For
1278 these, the ARRs are used to emulate the MTRRs.
1279 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1280 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1281 write-combining. All of these processors are supported by this code
1282 and it makes sense to say Y here if you have one of them.
1284 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1285 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1286 can lead to all sorts of problems, so it's good to say Y here.
1288 You can safely say Y even if your machine doesn't have MTRRs, you'll
1289 just add about 9 KB to your kernel.
1291 See <file:Documentation/x86/mtrr.txt> for more information.
1293 config MTRR_SANITIZER
1295 prompt "MTRR cleanup support"
1298 Convert MTRR layout from continuous to discrete, so X drivers can
1299 add writeback entries.
1301 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1302 The largest mtrr entry size for a continous block can be set with
1307 config MTRR_SANITIZER_ENABLE_DEFAULT
1308 int "MTRR cleanup enable value (0-1)"
1311 depends on MTRR_SANITIZER
1313 Enable mtrr cleanup default value
1315 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1316 int "MTRR cleanup spare reg num (0-7)"
1319 depends on MTRR_SANITIZER
1321 mtrr cleanup spare entries default, it can be changed via
1322 mtrr_spare_reg_nr=N on the kernel command line.
1326 prompt "x86 PAT support"
1329 Use PAT attributes to setup page level cache control.
1331 PATs are the modern equivalents of MTRRs and are much more
1332 flexible than MTRRs.
1334 Say N here if you see bootup problems (boot crash, boot hang,
1335 spontaneous reboots) or a non-working video driver.
1340 bool "EFI runtime service support"
1343 This enables the kernel to use EFI runtime services that are
1344 available (such as the EFI variable services).
1346 This option is only useful on systems that have EFI firmware.
1347 In addition, you should use the latest ELILO loader available
1348 at <http://elilo.sourceforge.net> in order to take advantage
1349 of EFI runtime services. However, even with this option, the
1350 resultant kernel should continue to boot on existing non-EFI
1355 prompt "Enable seccomp to safely compute untrusted bytecode"
1357 This kernel feature is useful for number crunching applications
1358 that may need to compute untrusted bytecode during their
1359 execution. By using pipes or other transports made available to
1360 the process as file descriptors supporting the read/write
1361 syscalls, it's possible to isolate those applications in
1362 their own address space using seccomp. Once seccomp is
1363 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1364 and the task is only allowed to execute a few safe syscalls
1365 defined by each seccomp mode.
1367 If unsure, say Y. Only embedded should say N here.
1369 config CC_STACKPROTECTOR_ALL
1372 config CC_STACKPROTECTOR
1373 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1374 select CC_STACKPROTECTOR_ALL
1376 This option turns on the -fstack-protector GCC feature. This
1377 feature puts, at the beginning of functions, a canary value on
1378 the stack just before the return address, and validates
1379 the value just before actually returning. Stack based buffer
1380 overflows (that need to overwrite this return address) now also
1381 overwrite the canary, which gets detected and the attack is then
1382 neutralized via a kernel panic.
1384 This feature requires gcc version 4.2 or above, or a distribution
1385 gcc with the feature backported. Older versions are automatically
1386 detected and for those versions, this configuration option is
1387 ignored. (and a warning is printed during bootup)
1389 source kernel/Kconfig.hz
1392 bool "kexec system call"
1394 kexec is a system call that implements the ability to shutdown your
1395 current kernel, and to start another kernel. It is like a reboot
1396 but it is independent of the system firmware. And like a reboot
1397 you can start any kernel with it, not just Linux.
1399 The name comes from the similarity to the exec system call.
1401 It is an ongoing process to be certain the hardware in a machine
1402 is properly shutdown, so do not be surprised if this code does not
1403 initially work for you. It may help to enable device hotplugging
1404 support. As of this writing the exact hardware interface is
1405 strongly in flux, so no good recommendation can be made.
1408 bool "kernel crash dumps"
1409 depends on X86_64 || (X86_32 && HIGHMEM)
1411 Generate crash dump after being started by kexec.
1412 This should be normally only set in special crash dump kernels
1413 which are loaded in the main kernel with kexec-tools into
1414 a specially reserved region and then later executed after
1415 a crash by kdump/kexec. The crash dump kernel must be compiled
1416 to a memory address not used by the main kernel or BIOS using
1417 PHYSICAL_START, or it must be built as a relocatable image
1418 (CONFIG_RELOCATABLE=y).
1419 For more details see Documentation/kdump/kdump.txt
1422 bool "kexec jump (EXPERIMENTAL)"
1423 depends on EXPERIMENTAL
1424 depends on KEXEC && HIBERNATION && X86_32
1426 Jump between original kernel and kexeced kernel and invoke
1427 code in physical address mode via KEXEC
1429 config PHYSICAL_START
1430 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1431 default "0x1000000" if X86_NUMAQ
1432 default "0x200000" if X86_64
1435 This gives the physical address where the kernel is loaded.
1437 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1438 bzImage will decompress itself to above physical address and
1439 run from there. Otherwise, bzImage will run from the address where
1440 it has been loaded by the boot loader and will ignore above physical
1443 In normal kdump cases one does not have to set/change this option
1444 as now bzImage can be compiled as a completely relocatable image
1445 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1446 address. This option is mainly useful for the folks who don't want
1447 to use a bzImage for capturing the crash dump and want to use a
1448 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1449 to be specifically compiled to run from a specific memory area
1450 (normally a reserved region) and this option comes handy.
1452 So if you are using bzImage for capturing the crash dump, leave
1453 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1454 Otherwise if you plan to use vmlinux for capturing the crash dump
1455 change this value to start of the reserved region (Typically 16MB
1456 0x1000000). In other words, it can be set based on the "X" value as
1457 specified in the "crashkernel=YM@XM" command line boot parameter
1458 passed to the panic-ed kernel. Typically this parameter is set as
1459 crashkernel=64M@16M. Please take a look at
1460 Documentation/kdump/kdump.txt for more details about crash dumps.
1462 Usage of bzImage for capturing the crash dump is recommended as
1463 one does not have to build two kernels. Same kernel can be used
1464 as production kernel and capture kernel. Above option should have
1465 gone away after relocatable bzImage support is introduced. But it
1466 is present because there are users out there who continue to use
1467 vmlinux for dump capture. This option should go away down the
1470 Don't change this unless you know what you are doing.
1473 bool "Build a relocatable kernel (EXPERIMENTAL)"
1474 depends on EXPERIMENTAL
1476 This builds a kernel image that retains relocation information
1477 so it can be loaded someplace besides the default 1MB.
1478 The relocations tend to make the kernel binary about 10% larger,
1479 but are discarded at runtime.
1481 One use is for the kexec on panic case where the recovery kernel
1482 must live at a different physical address than the primary
1485 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1486 it has been loaded at and the compile time physical address
1487 (CONFIG_PHYSICAL_START) is ignored.
1489 config PHYSICAL_ALIGN
1491 prompt "Alignment value to which kernel should be aligned" if X86_32
1492 default "0x100000" if X86_32
1493 default "0x200000" if X86_64
1494 range 0x2000 0x400000
1496 This value puts the alignment restrictions on physical address
1497 where kernel is loaded and run from. Kernel is compiled for an
1498 address which meets above alignment restriction.
1500 If bootloader loads the kernel at a non-aligned address and
1501 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1502 address aligned to above value and run from there.
1504 If bootloader loads the kernel at a non-aligned address and
1505 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1506 load address and decompress itself to the address it has been
1507 compiled for and run from there. The address for which kernel is
1508 compiled already meets above alignment restrictions. Hence the
1509 end result is that kernel runs from a physical address meeting
1510 above alignment restrictions.
1512 Don't change this unless you know what you are doing.
1515 bool "Support for hot-pluggable CPUs"
1516 depends on SMP && HOTPLUG
1518 Say Y here to allow turning CPUs off and on. CPUs can be
1519 controlled through /sys/devices/system/cpu.
1520 ( Note: power management support will enable this option
1521 automatically on SMP systems. )
1522 Say N if you want to disable CPU hotplug.
1526 prompt "Compat VDSO support"
1527 depends on X86_32 || IA32_EMULATION
1529 Map the 32-bit VDSO to the predictable old-style address too.
1531 Say N here if you are running a sufficiently recent glibc
1532 version (2.3.3 or later), to remove the high-mapped
1533 VDSO mapping and to exclusively use the randomized VDSO.
1538 bool "Built-in kernel command line"
1541 Allow for specifying boot arguments to the kernel at
1542 build time. On some systems (e.g. embedded ones), it is
1543 necessary or convenient to provide some or all of the
1544 kernel boot arguments with the kernel itself (that is,
1545 to not rely on the boot loader to provide them.)
1547 To compile command line arguments into the kernel,
1548 set this option to 'Y', then fill in the
1549 the boot arguments in CONFIG_CMDLINE.
1551 Systems with fully functional boot loaders (i.e. non-embedded)
1552 should leave this option set to 'N'.
1555 string "Built-in kernel command string"
1556 depends on CMDLINE_BOOL
1559 Enter arguments here that should be compiled into the kernel
1560 image and used at boot time. If the boot loader provides a
1561 command line at boot time, it is appended to this string to
1562 form the full kernel command line, when the system boots.
1564 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1565 change this behavior.
1567 In most cases, the command line (whether built-in or provided
1568 by the boot loader) should specify the device for the root
1571 config CMDLINE_OVERRIDE
1572 bool "Built-in command line overrides boot loader arguments"
1574 depends on CMDLINE_BOOL
1576 Set this option to 'Y' to have the kernel ignore the boot loader
1577 command line, and use ONLY the built-in command line.
1579 This is used to work around broken boot loaders. This should
1580 be set to 'N' under normal conditions.
1584 config ARCH_ENABLE_MEMORY_HOTPLUG
1586 depends on X86_64 || (X86_32 && HIGHMEM)
1588 config ARCH_ENABLE_MEMORY_HOTREMOVE
1590 depends on MEMORY_HOTPLUG
1592 config HAVE_ARCH_EARLY_PFN_TO_NID
1596 menu "Power management and ACPI options"
1598 config ARCH_HIBERNATION_HEADER
1600 depends on X86_64 && HIBERNATION
1602 source "kernel/power/Kconfig"
1604 source "drivers/acpi/Kconfig"
1609 depends on APM || APM_MODULE
1612 tristate "APM (Advanced Power Management) BIOS support"
1613 depends on X86_32 && PM_SLEEP
1615 APM is a BIOS specification for saving power using several different
1616 techniques. This is mostly useful for battery powered laptops with
1617 APM compliant BIOSes. If you say Y here, the system time will be
1618 reset after a RESUME operation, the /proc/apm device will provide
1619 battery status information, and user-space programs will receive
1620 notification of APM "events" (e.g. battery status change).
1622 If you select "Y" here, you can disable actual use of the APM
1623 BIOS by passing the "apm=off" option to the kernel at boot time.
1625 Note that the APM support is almost completely disabled for
1626 machines with more than one CPU.
1628 In order to use APM, you will need supporting software. For location
1629 and more information, read <file:Documentation/power/pm.txt> and the
1630 Battery Powered Linux mini-HOWTO, available from
1631 <http://www.tldp.org/docs.html#howto>.
1633 This driver does not spin down disk drives (see the hdparm(8)
1634 manpage ("man 8 hdparm") for that), and it doesn't turn off
1635 VESA-compliant "green" monitors.
1637 This driver does not support the TI 4000M TravelMate and the ACER
1638 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1639 desktop machines also don't have compliant BIOSes, and this driver
1640 may cause those machines to panic during the boot phase.
1642 Generally, if you don't have a battery in your machine, there isn't
1643 much point in using this driver and you should say N. If you get
1644 random kernel OOPSes or reboots that don't seem to be related to
1645 anything, try disabling/enabling this option (or disabling/enabling
1648 Some other things you should try when experiencing seemingly random,
1651 1) make sure that you have enough swap space and that it is
1653 2) pass the "no-hlt" option to the kernel
1654 3) switch on floating point emulation in the kernel and pass
1655 the "no387" option to the kernel
1656 4) pass the "floppy=nodma" option to the kernel
1657 5) pass the "mem=4M" option to the kernel (thereby disabling
1658 all but the first 4 MB of RAM)
1659 6) make sure that the CPU is not over clocked.
1660 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1661 8) disable the cache from your BIOS settings
1662 9) install a fan for the video card or exchange video RAM
1663 10) install a better fan for the CPU
1664 11) exchange RAM chips
1665 12) exchange the motherboard.
1667 To compile this driver as a module, choose M here: the
1668 module will be called apm.
1672 config APM_IGNORE_USER_SUSPEND
1673 bool "Ignore USER SUSPEND"
1675 This option will ignore USER SUSPEND requests. On machines with a
1676 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1677 series notebooks, it is necessary to say Y because of a BIOS bug.
1679 config APM_DO_ENABLE
1680 bool "Enable PM at boot time"
1682 Enable APM features at boot time. From page 36 of the APM BIOS
1683 specification: "When disabled, the APM BIOS does not automatically
1684 power manage devices, enter the Standby State, enter the Suspend
1685 State, or take power saving steps in response to CPU Idle calls."
1686 This driver will make CPU Idle calls when Linux is idle (unless this
1687 feature is turned off -- see "Do CPU IDLE calls", below). This
1688 should always save battery power, but more complicated APM features
1689 will be dependent on your BIOS implementation. You may need to turn
1690 this option off if your computer hangs at boot time when using APM
1691 support, or if it beeps continuously instead of suspending. Turn
1692 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1693 T400CDT. This is off by default since most machines do fine without
1697 bool "Make CPU Idle calls when idle"
1699 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1700 On some machines, this can activate improved power savings, such as
1701 a slowed CPU clock rate, when the machine is idle. These idle calls
1702 are made after the idle loop has run for some length of time (e.g.,
1703 333 mS). On some machines, this will cause a hang at boot time or
1704 whenever the CPU becomes idle. (On machines with more than one CPU,
1705 this option does nothing.)
1707 config APM_DISPLAY_BLANK
1708 bool "Enable console blanking using APM"
1710 Enable console blanking using the APM. Some laptops can use this to
1711 turn off the LCD backlight when the screen blanker of the Linux
1712 virtual console blanks the screen. Note that this is only used by
1713 the virtual console screen blanker, and won't turn off the backlight
1714 when using the X Window system. This also doesn't have anything to
1715 do with your VESA-compliant power-saving monitor. Further, this
1716 option doesn't work for all laptops -- it might not turn off your
1717 backlight at all, or it might print a lot of errors to the console,
1718 especially if you are using gpm.
1720 config APM_ALLOW_INTS
1721 bool "Allow interrupts during APM BIOS calls"
1723 Normally we disable external interrupts while we are making calls to
1724 the APM BIOS as a measure to lessen the effects of a badly behaving
1725 BIOS implementation. The BIOS should reenable interrupts if it
1726 needs to. Unfortunately, some BIOSes do not -- especially those in
1727 many of the newer IBM Thinkpads. If you experience hangs when you
1728 suspend, try setting this to Y. Otherwise, say N.
1732 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1734 source "drivers/cpuidle/Kconfig"
1736 source "drivers/idle/Kconfig"
1741 menu "Bus options (PCI etc.)"
1746 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1748 Find out whether you have a PCI motherboard. PCI is the name of a
1749 bus system, i.e. the way the CPU talks to the other stuff inside
1750 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1751 VESA. If you have PCI, say Y, otherwise N.
1754 prompt "PCI access mode"
1755 depends on X86_32 && PCI
1758 On PCI systems, the BIOS can be used to detect the PCI devices and
1759 determine their configuration. However, some old PCI motherboards
1760 have BIOS bugs and may crash if this is done. Also, some embedded
1761 PCI-based systems don't have any BIOS at all. Linux can also try to
1762 detect the PCI hardware directly without using the BIOS.
1764 With this option, you can specify how Linux should detect the
1765 PCI devices. If you choose "BIOS", the BIOS will be used,
1766 if you choose "Direct", the BIOS won't be used, and if you
1767 choose "MMConfig", then PCI Express MMCONFIG will be used.
1768 If you choose "Any", the kernel will try MMCONFIG, then the
1769 direct access method and falls back to the BIOS if that doesn't
1770 work. If unsure, go with the default, which is "Any".
1775 config PCI_GOMMCONFIG
1792 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1794 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1797 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1801 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1805 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1812 bool "Support mmconfig PCI config space access"
1813 depends on X86_64 && PCI && ACPI
1816 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1817 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1819 DMA remapping (DMAR) devices support enables independent address
1820 translations for Direct Memory Access (DMA) from devices.
1821 These DMA remapping devices are reported via ACPI tables
1822 and include PCI device scope covered by these DMA
1825 config DMAR_DEFAULT_ON
1827 prompt "Enable DMA Remapping Devices by default"
1830 Selecting this option will enable a DMAR device at boot time if
1831 one is found. If this option is not selected, DMAR support can
1832 be enabled by passing intel_iommu=on to the kernel. It is
1833 recommended you say N here while the DMAR code remains
1838 prompt "Support for Graphics workaround"
1841 Current Graphics drivers tend to use physical address
1842 for DMA and avoid using DMA APIs. Setting this config
1843 option permits the IOMMU driver to set a unity map for
1844 all the OS-visible memory. Hence the driver can continue
1845 to use physical addresses for DMA.
1847 config DMAR_FLOPPY_WA
1851 Floppy disk drivers are know to bypass DMA API calls
1852 thereby failing to work when IOMMU is enabled. This
1853 workaround will setup a 1:1 mapping for the first
1854 16M to make floppy (an ISA device) work.
1857 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1858 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1861 Supports Interrupt remapping for IO-APIC and MSI devices.
1862 To use x2apic mode in the CPU's which support x2APIC enhancements or
1863 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1865 source "drivers/pci/pcie/Kconfig"
1867 source "drivers/pci/Kconfig"
1869 # x86_64 have no ISA slots, but do have ISA-style DMA.
1878 Find out whether you have ISA slots on your motherboard. ISA is the
1879 name of a bus system, i.e. the way the CPU talks to the other stuff
1880 inside your box. Other bus systems are PCI, EISA, MicroChannel
1881 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1882 newer boards don't support it. If you have ISA, say Y, otherwise N.
1888 The Extended Industry Standard Architecture (EISA) bus was
1889 developed as an open alternative to the IBM MicroChannel bus.
1891 The EISA bus provided some of the features of the IBM MicroChannel
1892 bus while maintaining backward compatibility with cards made for
1893 the older ISA bus. The EISA bus saw limited use between 1988 and
1894 1995 when it was made obsolete by the PCI bus.
1896 Say Y here if you are building a kernel for an EISA-based machine.
1900 source "drivers/eisa/Kconfig"
1905 MicroChannel Architecture is found in some IBM PS/2 machines and
1906 laptops. It is a bus system similar to PCI or ISA. See
1907 <file:Documentation/mca.txt> (and especially the web page given
1908 there) before attempting to build an MCA bus kernel.
1910 source "drivers/mca/Kconfig"
1913 tristate "NatSemi SCx200 support"
1915 This provides basic support for National Semiconductor's
1916 (now AMD's) Geode processors. The driver probes for the
1917 PCI-IDs of several on-chip devices, so its a good dependency
1918 for other scx200_* drivers.
1920 If compiled as a module, the driver is named scx200.
1922 config SCx200HR_TIMER
1923 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1924 depends on SCx200 && GENERIC_TIME
1927 This driver provides a clocksource built upon the on-chip
1928 27MHz high-resolution timer. Its also a workaround for
1929 NSC Geode SC-1100's buggy TSC, which loses time when the
1930 processor goes idle (as is done by the scheduler). The
1931 other workaround is idle=poll boot option.
1933 config GEODE_MFGPT_TIMER
1935 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1936 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1938 This driver provides a clock event source based on the MFGPT
1939 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1940 MFGPTs have a better resolution and max interval than the
1941 generic PIT, and are suitable for use as high-res timers.
1944 bool "One Laptop Per Child support"
1947 Add support for detecting the unique features of the OLPC
1954 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1956 source "drivers/pcmcia/Kconfig"
1958 source "drivers/pci/hotplug/Kconfig"
1963 menu "Executable file formats / Emulations"
1965 source "fs/Kconfig.binfmt"
1967 config IA32_EMULATION
1968 bool "IA32 Emulation"
1970 select COMPAT_BINFMT_ELF
1972 Include code to run 32-bit programs under a 64-bit kernel. You should
1973 likely turn this on, unless you're 100% sure that you don't have any
1974 32-bit programs left.
1977 tristate "IA32 a.out support"
1978 depends on IA32_EMULATION
1980 Support old a.out binaries in the 32bit emulation.
1984 depends on IA32_EMULATION
1986 config COMPAT_FOR_U64_ALIGNMENT
1990 config SYSVIPC_COMPAT
1992 depends on COMPAT && SYSVIPC
1997 config HAVE_ATOMIC_IOMAP
2001 source "net/Kconfig"
2003 source "drivers/Kconfig"
2005 source "drivers/firmware/Kconfig"
2009 source "arch/x86/Kconfig.debug"
2011 source "security/Kconfig"
2013 source "crypto/Kconfig"
2015 source "arch/x86/kvm/Kconfig"
2017 source "lib/Kconfig"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blob