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_PERF_EVENTS if (!M386 && !M486)
28 select HAVE_IOREMAP_PROT
30 select ARCH_WANT_OPTIONAL_GPIOLIB
31 select ARCH_WANT_FRAME_POINTERS
33 select HAVE_KRETPROBES
34 select HAVE_FTRACE_MCOUNT_RECORD
35 select HAVE_DYNAMIC_FTRACE
36 select HAVE_FUNCTION_TRACER
37 select HAVE_FUNCTION_GRAPH_TRACER
38 select HAVE_FUNCTION_GRAPH_FP_TEST
39 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
40 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
41 select HAVE_SYSCALL_TRACEPOINTS
44 select HAVE_ARCH_TRACEHOOK
45 select HAVE_GENERIC_DMA_COHERENT if X86_32
46 select HAVE_EFFICIENT_UNALIGNED_ACCESS
47 select USER_STACKTRACE_SUPPORT
48 select HAVE_DMA_API_DEBUG
49 select HAVE_KERNEL_GZIP
50 select HAVE_KERNEL_BZIP2
51 select HAVE_KERNEL_LZMA
52 select HAVE_KERNEL_LZO
53 select HAVE_HW_BREAKPOINT
56 select HAVE_ARCH_KMEMCHECK
57 select HAVE_USER_RETURN_NOTIFIER
61 default "elf32-i386" if X86_32
62 default "elf64-x86-64" if X86_64
66 default "arch/x86/configs/i386_defconfig" if X86_32
67 default "arch/x86/configs/x86_64_defconfig" if X86_64
72 config GENERIC_CMOS_UPDATE
75 config CLOCKSOURCE_WATCHDOG
78 config GENERIC_CLOCKEVENTS
81 config GENERIC_CLOCKEVENTS_BROADCAST
83 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
85 config LOCKDEP_SUPPORT
88 config STACKTRACE_SUPPORT
91 config HAVE_LATENCYTOP_SUPPORT
103 config GENERIC_ISA_DMA
112 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
114 config GENERIC_BUG_RELATIVE_POINTERS
117 config GENERIC_HWEIGHT
123 config ARCH_MAY_HAVE_PC_FDC
126 config RWSEM_GENERIC_SPINLOCK
129 config RWSEM_XCHGADD_ALGORITHM
132 config ARCH_HAS_CPU_IDLE_WAIT
135 config GENERIC_CALIBRATE_DELAY
138 config GENERIC_TIME_VSYSCALL
142 config ARCH_HAS_CPU_RELAX
145 config ARCH_HAS_DEFAULT_IDLE
148 config ARCH_HAS_CACHE_LINE_SIZE
151 config HAVE_SETUP_PER_CPU_AREA
154 config NEED_PER_CPU_EMBED_FIRST_CHUNK
157 config NEED_PER_CPU_PAGE_FIRST_CHUNK
160 config HAVE_CPUMASK_OF_CPU_MAP
163 config ARCH_HIBERNATION_POSSIBLE
166 config ARCH_SUSPEND_POSSIBLE
173 config ARCH_POPULATES_NODE_MAP
180 config ARCH_SUPPORTS_OPTIMIZED_INLINING
183 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
186 config HAVE_INTEL_TXT
188 depends on EXPERIMENTAL && DMAR && ACPI
190 # Use the generic interrupt handling code in kernel/irq/:
191 config GENERIC_HARDIRQS
195 config GENERIC_HARDIRQS_NO__DO_IRQ
198 config GENERIC_IRQ_PROBE
202 config GENERIC_PENDING_IRQ
204 depends on GENERIC_HARDIRQS && SMP
207 config USE_GENERIC_SMP_HELPERS
213 depends on X86_32 && SMP
217 depends on X86_64 && SMP
224 config X86_TRAMPOLINE
226 depends on SMP || (64BIT && ACPI_SLEEP)
229 config X86_32_LAZY_GS
231 depends on X86_32 && !CC_STACKPROTECTOR
235 source "init/Kconfig"
236 source "kernel/Kconfig.freezer"
238 menu "Processor type and features"
240 source "kernel/time/Kconfig"
243 bool "Symmetric multi-processing support"
245 This enables support for systems with more than one CPU. If you have
246 a system with only one CPU, like most personal computers, say N. If
247 you have a system with more than one CPU, say Y.
249 If you say N here, the kernel will run on single and multiprocessor
250 machines, but will use only one CPU of a multiprocessor machine. If
251 you say Y here, the kernel will run on many, but not all,
252 singleprocessor machines. On a singleprocessor machine, the kernel
253 will run faster if you say N here.
255 Note that if you say Y here and choose architecture "586" or
256 "Pentium" under "Processor family", the kernel will not work on 486
257 architectures. Similarly, multiprocessor kernels for the "PPro"
258 architecture may not work on all Pentium based boards.
260 People using multiprocessor machines who say Y here should also say
261 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
262 Management" code will be disabled if you say Y here.
264 See also <file:Documentation/i386/IO-APIC.txt>,
265 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
266 <http://www.tldp.org/docs.html#howto>.
268 If you don't know what to do here, say N.
271 bool "Support x2apic"
272 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
274 This enables x2apic support on CPUs that have this feature.
276 This allows 32-bit apic IDs (so it can support very large systems),
277 and accesses the local apic via MSRs not via mmio.
279 If you don't know what to do here, say N.
282 bool "Support sparse irq numbering"
283 depends on PCI_MSI || HT_IRQ
285 This enables support for sparse irqs. This is useful for distro
286 kernels that want to define a high CONFIG_NR_CPUS value but still
287 want to have low kernel memory footprint on smaller machines.
289 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
290 out the irq_desc[] array in a more NUMA-friendly way. )
292 If you don't know what to do here, say N.
296 depends on SPARSE_IRQ && NUMA
299 bool "Enable MPS table" if ACPI
301 depends on X86_LOCAL_APIC
303 For old smp systems that do not have proper acpi support. Newer systems
304 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
307 bool "Support for big SMP systems with more than 8 CPUs"
308 depends on X86_32 && SMP
310 This option is needed for the systems that have more than 8 CPUs
313 config X86_EXTENDED_PLATFORM
314 bool "Support for extended (non-PC) x86 platforms"
317 If you disable this option then the kernel will only support
318 standard PC platforms. (which covers the vast majority of
321 If you enable this option then you'll be able to select support
322 for the following (non-PC) 32 bit x86 platforms:
326 SGI 320/540 (Visual Workstation)
327 Summit/EXA (IBM x440)
328 Unisys ES7000 IA32 series
329 Moorestown MID devices
331 If you have one of these systems, or if you want to build a
332 generic distribution kernel, say Y here - otherwise say N.
336 config X86_EXTENDED_PLATFORM
337 bool "Support for extended (non-PC) x86 platforms"
340 If you disable this option then the kernel will only support
341 standard PC platforms. (which covers the vast majority of
344 If you enable this option then you'll be able to select support
345 for the following (non-PC) 64 bit x86 platforms:
349 If you have one of these systems, or if you want to build a
350 generic distribution kernel, say Y here - otherwise say N.
352 # This is an alphabetically sorted list of 64 bit extended platforms
353 # Please maintain the alphabetic order if and when there are additions
358 depends on X86_64 && PCI
359 depends on X86_EXTENDED_PLATFORM
361 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
362 supposed to run on these EM64T-based machines. Only choose this option
363 if you have one of these machines.
366 bool "SGI Ultraviolet"
368 depends on X86_EXTENDED_PLATFORM
370 depends on X86_X2APIC
372 This option is needed in order to support SGI Ultraviolet systems.
373 If you don't have one of these, you should say N here.
375 # Following is an alphabetically sorted list of 32 bit extended platforms
376 # Please maintain the alphabetic order if and when there are additions
381 depends on X86_EXTENDED_PLATFORM
383 Select this for an AMD Elan processor.
385 Do not use this option for K6/Athlon/Opteron processors!
387 If unsure, choose "PC-compatible" instead.
390 bool "Moorestown MID platform"
392 depends on X86_EXTENDED_PLATFORM
394 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
395 Internet Device(MID) platform. Moorestown consists of two chips:
396 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
397 Unlike standard x86 PCs, Moorestown does not have many legacy devices
398 nor standard legacy replacement devices/features. e.g. Moorestown does
399 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
402 bool "RDC R-321x SoC"
404 depends on X86_EXTENDED_PLATFORM
406 select X86_REBOOTFIXUPS
408 This option is needed for RDC R-321x system-on-chip, also known
410 If you don't have one of these chips, you should say N here.
412 config X86_32_NON_STANDARD
413 bool "Support non-standard 32-bit SMP architectures"
414 depends on X86_32 && SMP
415 depends on X86_EXTENDED_PLATFORM
417 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
418 subarchitectures. It is intended for a generic binary kernel.
419 if you select them all, kernel will probe it one by one. and will
422 # Alphabetically sorted list of Non standard 32 bit platforms
425 bool "NUMAQ (IBM/Sequent)"
426 depends on X86_32_NON_STANDARD
430 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
431 NUMA multiquad box. This changes the way that processors are
432 bootstrapped, and uses Clustered Logical APIC addressing mode instead
433 of Flat Logical. You will need a new lynxer.elf file to flash your
434 firmware with - send email to <Martin.Bligh@us.ibm.com>.
436 config X86_SUPPORTS_MEMORY_FAILURE
438 # MCE code calls memory_failure():
440 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
441 depends on !X86_NUMAQ
442 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
443 depends on X86_64 || !SPARSEMEM
444 select ARCH_SUPPORTS_MEMORY_FAILURE
448 bool "SGI 320/540 (Visual Workstation)"
449 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
450 depends on X86_32_NON_STANDARD
452 The SGI Visual Workstation series is an IA32-based workstation
453 based on SGI systems chips with some legacy PC hardware attached.
455 Say Y here to create a kernel to run on the SGI 320 or 540.
457 A kernel compiled for the Visual Workstation will run on general
458 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
461 bool "Summit/EXA (IBM x440)"
462 depends on X86_32_NON_STANDARD
464 This option is needed for IBM systems that use the Summit/EXA chipset.
465 In particular, it is needed for the x440.
468 bool "Unisys ES7000 IA32 series"
469 depends on X86_32_NON_STANDARD && X86_BIGSMP
471 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
472 supposed to run on an IA32-based Unisys ES7000 system.
474 config SCHED_OMIT_FRAME_POINTER
476 prompt "Single-depth WCHAN output"
479 Calculate simpler /proc/<PID>/wchan values. If this option
480 is disabled then wchan values will recurse back to the
481 caller function. This provides more accurate wchan values,
482 at the expense of slightly more scheduling overhead.
484 If in doubt, say "Y".
486 menuconfig PARAVIRT_GUEST
487 bool "Paravirtualized guest support"
489 Say Y here to get to see options related to running Linux under
490 various hypervisors. This option alone does not add any kernel code.
492 If you say N, all options in this submenu will be skipped and disabled.
496 source "arch/x86/xen/Kconfig"
499 bool "VMI Guest support (DEPRECATED)"
503 VMI provides a paravirtualized interface to the VMware ESX server
504 (it could be used by other hypervisors in theory too, but is not
505 at the moment), by linking the kernel to a GPL-ed ROM module
506 provided by the hypervisor.
508 As of September 2009, VMware has started a phased retirement
509 of this feature from VMware's products. Please see
510 feature-removal-schedule.txt for details. If you are
511 planning to enable this option, please note that you cannot
512 live migrate a VMI enabled VM to a future VMware product,
513 which doesn't support VMI. So if you expect your kernel to
514 seamlessly migrate to newer VMware products, keep this
518 bool "KVM paravirtualized clock"
520 select PARAVIRT_CLOCK
522 Turning on this option will allow you to run a paravirtualized clock
523 when running over the KVM hypervisor. Instead of relying on a PIT
524 (or probably other) emulation by the underlying device model, the host
525 provides the guest with timing infrastructure such as time of day, and
529 bool "KVM Guest support"
532 This option enables various optimizations for running under the KVM
535 source "arch/x86/lguest/Kconfig"
538 bool "Enable paravirtualization code"
540 This changes the kernel so it can modify itself when it is run
541 under a hypervisor, potentially improving performance significantly
542 over full virtualization. However, when run without a hypervisor
543 the kernel is theoretically slower and slightly larger.
545 config PARAVIRT_SPINLOCKS
546 bool "Paravirtualization layer for spinlocks"
547 depends on PARAVIRT && SMP && EXPERIMENTAL
549 Paravirtualized spinlocks allow a pvops backend to replace the
550 spinlock implementation with something virtualization-friendly
551 (for example, block the virtual CPU rather than spinning).
553 Unfortunately the downside is an up to 5% performance hit on
554 native kernels, with various workloads.
556 If you are unsure how to answer this question, answer N.
558 config PARAVIRT_CLOCK
564 config PARAVIRT_DEBUG
565 bool "paravirt-ops debugging"
566 depends on PARAVIRT && DEBUG_KERNEL
568 Enable to debug paravirt_ops internals. Specifically, BUG if
569 a paravirt_op is missing when it is called.
574 This option adds a kernel parameter 'memtest', which allows memtest
576 memtest=0, mean disabled; -- default
577 memtest=1, mean do 1 test pattern;
579 memtest=4, mean do 4 test patterns.
580 If you are unsure how to answer this question, answer N.
582 config X86_SUMMIT_NUMA
584 depends on X86_32 && NUMA && X86_32_NON_STANDARD
586 config X86_CYCLONE_TIMER
588 depends on X86_32_NON_STANDARD
590 source "arch/x86/Kconfig.cpu"
594 prompt "HPET Timer Support" if X86_32
596 Use the IA-PC HPET (High Precision Event Timer) to manage
597 time in preference to the PIT and RTC, if a HPET is
599 HPET is the next generation timer replacing legacy 8254s.
600 The HPET provides a stable time base on SMP
601 systems, unlike the TSC, but it is more expensive to access,
602 as it is off-chip. You can find the HPET spec at
603 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
605 You can safely choose Y here. However, HPET will only be
606 activated if the platform and the BIOS support this feature.
607 Otherwise the 8254 will be used for timing services.
609 Choose N to continue using the legacy 8254 timer.
611 config HPET_EMULATE_RTC
613 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
615 # Mark as embedded because too many people got it wrong.
616 # The code disables itself when not needed.
619 bool "Enable DMI scanning" if EMBEDDED
621 Enabled scanning of DMI to identify machine quirks. Say Y
622 here unless you have verified that your setup is not
623 affected by entries in the DMI blacklist. Required by PNP
627 bool "GART IOMMU support" if EMBEDDED
630 depends on X86_64 && PCI
632 Support for full DMA access of devices with 32bit memory access only
633 on systems with more than 3GB. This is usually needed for USB,
634 sound, many IDE/SATA chipsets and some other devices.
635 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
636 based hardware IOMMU and a software bounce buffer based IOMMU used
637 on Intel systems and as fallback.
638 The code is only active when needed (enough memory and limited
639 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
643 bool "IBM Calgary IOMMU support"
645 depends on X86_64 && PCI && EXPERIMENTAL
647 Support for hardware IOMMUs in IBM's xSeries x366 and x460
648 systems. Needed to run systems with more than 3GB of memory
649 properly with 32-bit PCI devices that do not support DAC
650 (Double Address Cycle). Calgary also supports bus level
651 isolation, where all DMAs pass through the IOMMU. This
652 prevents them from going anywhere except their intended
653 destination. This catches hard-to-find kernel bugs and
654 mis-behaving drivers and devices that do not use the DMA-API
655 properly to set up their DMA buffers. The IOMMU can be
656 turned off at boot time with the iommu=off parameter.
657 Normally the kernel will make the right choice by itself.
660 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
662 prompt "Should Calgary be enabled by default?"
663 depends on CALGARY_IOMMU
665 Should Calgary be enabled by default? if you choose 'y', Calgary
666 will be used (if it exists). If you choose 'n', Calgary will not be
667 used even if it exists. If you choose 'n' and would like to use
668 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
672 bool "AMD IOMMU support"
675 depends on X86_64 && PCI && ACPI
677 With this option you can enable support for AMD IOMMU hardware in
678 your system. An IOMMU is a hardware component which provides
679 remapping of DMA memory accesses from devices. With an AMD IOMMU you
680 can isolate the the DMA memory of different devices and protect the
681 system from misbehaving device drivers or hardware.
683 You can find out if your system has an AMD IOMMU if you look into
684 your BIOS for an option to enable it or if you have an IVRS ACPI
687 config AMD_IOMMU_STATS
688 bool "Export AMD IOMMU statistics to debugfs"
692 This option enables code in the AMD IOMMU driver to collect various
693 statistics about whats happening in the driver and exports that
694 information to userspace via debugfs.
697 # need this always selected by IOMMU for the VIA workaround
701 Support for software bounce buffers used on x86-64 systems
702 which don't have a hardware IOMMU (e.g. the current generation
703 of Intel's x86-64 CPUs). Using this PCI devices which can only
704 access 32-bits of memory can be used on systems with more than
705 3 GB of memory. If unsure, say Y.
708 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
711 def_bool (AMD_IOMMU || DMAR)
714 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
715 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
716 select CPUMASK_OFFSTACK
719 Configure maximum number of CPUS and NUMA Nodes for this architecture.
723 int "Maximum number of CPUs" if SMP && !MAXSMP
724 range 2 8 if SMP && X86_32 && !X86_BIGSMP
725 range 2 512 if SMP && !MAXSMP
727 default "4096" if MAXSMP
728 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
731 This allows you to specify the maximum number of CPUs which this
732 kernel will support. The maximum supported value is 512 and the
733 minimum value which makes sense is 2.
735 This is purely to save memory - each supported CPU adds
736 approximately eight kilobytes to the kernel image.
739 bool "SMT (Hyperthreading) scheduler support"
742 SMT scheduler support improves the CPU scheduler's decision making
743 when dealing with Intel Pentium 4 chips with HyperThreading at a
744 cost of slightly increased overhead in some places. If unsure say
749 prompt "Multi-core scheduler support"
752 Multi-core scheduler support improves the CPU scheduler's decision
753 making when dealing with multi-core CPU chips at a cost of slightly
754 increased overhead in some places. If unsure say N here.
756 source "kernel/Kconfig.preempt"
759 bool "Local APIC support on uniprocessors"
760 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
762 A local APIC (Advanced Programmable Interrupt Controller) is an
763 integrated interrupt controller in the CPU. If you have a single-CPU
764 system which has a processor with a local APIC, you can say Y here to
765 enable and use it. If you say Y here even though your machine doesn't
766 have a local APIC, then the kernel will still run with no slowdown at
767 all. The local APIC supports CPU-generated self-interrupts (timer,
768 performance counters), and the NMI watchdog which detects hard
772 bool "IO-APIC support on uniprocessors"
773 depends on X86_UP_APIC
775 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
776 SMP-capable replacement for PC-style interrupt controllers. Most
777 SMP systems and many recent uniprocessor systems have one.
779 If you have a single-CPU system with an IO-APIC, you can say Y here
780 to use it. If you say Y here even though your machine doesn't have
781 an IO-APIC, then the kernel will still run with no slowdown at all.
783 config X86_LOCAL_APIC
785 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
789 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
791 config X86_VISWS_APIC
793 depends on X86_32 && X86_VISWS
795 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
796 bool "Reroute for broken boot IRQs"
798 depends on X86_IO_APIC
800 This option enables a workaround that fixes a source of
801 spurious interrupts. This is recommended when threaded
802 interrupt handling is used on systems where the generation of
803 superfluous "boot interrupts" cannot be disabled.
805 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
806 entry in the chipset's IO-APIC is masked (as, e.g. the RT
807 kernel does during interrupt handling). On chipsets where this
808 boot IRQ generation cannot be disabled, this workaround keeps
809 the original IRQ line masked so that only the equivalent "boot
810 IRQ" is delivered to the CPUs. The workaround also tells the
811 kernel to set up the IRQ handler on the boot IRQ line. In this
812 way only one interrupt is delivered to the kernel. Otherwise
813 the spurious second interrupt may cause the kernel to bring
814 down (vital) interrupt lines.
816 Only affects "broken" chipsets. Interrupt sharing may be
817 increased on these systems.
820 bool "Machine Check / overheating reporting"
822 Machine Check support allows the processor to notify the
823 kernel if it detects a problem (e.g. overheating, data corruption).
824 The action the kernel takes depends on the severity of the problem,
825 ranging from warning messages to halting the machine.
829 prompt "Intel MCE features"
830 depends on X86_MCE && X86_LOCAL_APIC
832 Additional support for intel specific MCE features such as
837 prompt "AMD MCE features"
838 depends on X86_MCE && X86_LOCAL_APIC
840 Additional support for AMD specific MCE features such as
841 the DRAM Error Threshold.
843 config X86_ANCIENT_MCE
845 depends on X86_32 && X86_MCE
846 prompt "Support for old Pentium 5 / WinChip machine checks"
848 Include support for machine check handling on old Pentium 5 or WinChip
849 systems. These typically need to be enabled explicitely on the command
852 config X86_MCE_THRESHOLD
853 depends on X86_MCE_AMD || X86_MCE_INTEL
857 config X86_MCE_INJECT
859 tristate "Machine check injector support"
861 Provide support for injecting machine checks for testing purposes.
862 If you don't know what a machine check is and you don't do kernel
863 QA it is safe to say n.
865 config X86_THERMAL_VECTOR
867 depends on X86_MCE_INTEL
870 bool "Enable VM86 support" if EMBEDDED
874 This option is required by programs like DOSEMU to run 16-bit legacy
875 code on X86 processors. It also may be needed by software like
876 XFree86 to initialize some video cards via BIOS. Disabling this
877 option saves about 6k.
880 tristate "Toshiba Laptop support"
883 This adds a driver to safely access the System Management Mode of
884 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
885 not work on models with a Phoenix BIOS. The System Management Mode
886 is used to set the BIOS and power saving options on Toshiba portables.
888 For information on utilities to make use of this driver see the
889 Toshiba Linux utilities web site at:
890 <http://www.buzzard.org.uk/toshiba/>.
892 Say Y if you intend to run this kernel on a Toshiba portable.
896 tristate "Dell laptop support"
898 This adds a driver to safely access the System Management Mode
899 of the CPU on the Dell Inspiron 8000. The System Management Mode
900 is used to read cpu temperature and cooling fan status and to
901 control the fans on the I8K portables.
903 This driver has been tested only on the Inspiron 8000 but it may
904 also work with other Dell laptops. You can force loading on other
905 models by passing the parameter `force=1' to the module. Use at
908 For information on utilities to make use of this driver see the
909 I8K Linux utilities web site at:
910 <http://people.debian.org/~dz/i8k/>
912 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
915 config X86_REBOOTFIXUPS
916 bool "Enable X86 board specific fixups for reboot"
919 This enables chipset and/or board specific fixups to be done
920 in order to get reboot to work correctly. This is only needed on
921 some combinations of hardware and BIOS. The symptom, for which
922 this config is intended, is when reboot ends with a stalled/hung
925 Currently, the only fixup is for the Geode machines using
926 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
928 Say Y if you want to enable the fixup. Currently, it's safe to
929 enable this option even if you don't need it.
933 tristate "/dev/cpu/microcode - microcode support"
936 If you say Y here, you will be able to update the microcode on
937 certain Intel and AMD processors. The Intel support is for the
938 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
939 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
940 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
941 You will obviously need the actual microcode binary data itself
942 which is not shipped with the Linux kernel.
944 This option selects the general module only, you need to select
945 at least one vendor specific module as well.
947 To compile this driver as a module, choose M here: the
948 module will be called microcode.
950 config MICROCODE_INTEL
951 bool "Intel microcode patch loading support"
956 This options enables microcode patch loading support for Intel
959 For latest news and information on obtaining all the required
960 Intel ingredients for this driver, check:
961 <http://www.urbanmyth.org/microcode/>.
964 bool "AMD microcode patch loading support"
968 If you select this option, microcode patch loading support for AMD
969 processors will be enabled.
971 config MICROCODE_OLD_INTERFACE
976 tristate "/dev/cpu/*/msr - Model-specific register support"
978 This device gives privileged processes access to the x86
979 Model-Specific Registers (MSRs). It is a character device with
980 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
981 MSR accesses are directed to a specific CPU on multi-processor
985 tristate "/dev/cpu/*/cpuid - CPU information support"
987 This device gives processes access to the x86 CPUID instruction to
988 be executed on a specific processor. It is a character device
989 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
993 prompt "High Memory Support"
994 default HIGHMEM4G if !X86_NUMAQ
995 default HIGHMEM64G if X86_NUMAQ
1000 depends on !X86_NUMAQ
1002 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1003 However, the address space of 32-bit x86 processors is only 4
1004 Gigabytes large. That means that, if you have a large amount of
1005 physical memory, not all of it can be "permanently mapped" by the
1006 kernel. The physical memory that's not permanently mapped is called
1009 If you are compiling a kernel which will never run on a machine with
1010 more than 1 Gigabyte total physical RAM, answer "off" here (default
1011 choice and suitable for most users). This will result in a "3GB/1GB"
1012 split: 3GB are mapped so that each process sees a 3GB virtual memory
1013 space and the remaining part of the 4GB virtual memory space is used
1014 by the kernel to permanently map as much physical memory as
1017 If the machine has between 1 and 4 Gigabytes physical RAM, then
1020 If more than 4 Gigabytes is used then answer "64GB" here. This
1021 selection turns Intel PAE (Physical Address Extension) mode on.
1022 PAE implements 3-level paging on IA32 processors. PAE is fully
1023 supported by Linux, PAE mode is implemented on all recent Intel
1024 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1025 then the kernel will not boot on CPUs that don't support PAE!
1027 The actual amount of total physical memory will either be
1028 auto detected or can be forced by using a kernel command line option
1029 such as "mem=256M". (Try "man bootparam" or see the documentation of
1030 your boot loader (lilo or loadlin) about how to pass options to the
1031 kernel at boot time.)
1033 If unsure, say "off".
1037 depends on !X86_NUMAQ
1039 Select this if you have a 32-bit processor and between 1 and 4
1040 gigabytes of physical RAM.
1044 depends on !M386 && !M486
1047 Select this if you have a 32-bit processor and more than 4
1048 gigabytes of physical RAM.
1053 depends on EXPERIMENTAL
1054 prompt "Memory split" if EMBEDDED
1058 Select the desired split between kernel and user memory.
1060 If the address range available to the kernel is less than the
1061 physical memory installed, the remaining memory will be available
1062 as "high memory". Accessing high memory is a little more costly
1063 than low memory, as it needs to be mapped into the kernel first.
1064 Note that increasing the kernel address space limits the range
1065 available to user programs, making the address space there
1066 tighter. Selecting anything other than the default 3G/1G split
1067 will also likely make your kernel incompatible with binary-only
1070 If you are not absolutely sure what you are doing, leave this
1074 bool "3G/1G user/kernel split"
1075 config VMSPLIT_3G_OPT
1077 bool "3G/1G user/kernel split (for full 1G low memory)"
1079 bool "2G/2G user/kernel split"
1080 config VMSPLIT_2G_OPT
1082 bool "2G/2G user/kernel split (for full 2G low memory)"
1084 bool "1G/3G user/kernel split"
1089 default 0xB0000000 if VMSPLIT_3G_OPT
1090 default 0x80000000 if VMSPLIT_2G
1091 default 0x78000000 if VMSPLIT_2G_OPT
1092 default 0x40000000 if VMSPLIT_1G
1098 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1101 bool "PAE (Physical Address Extension) Support"
1102 depends on X86_32 && !HIGHMEM4G
1104 PAE is required for NX support, and furthermore enables
1105 larger swapspace support for non-overcommit purposes. It
1106 has the cost of more pagetable lookup overhead, and also
1107 consumes more pagetable space per process.
1109 config ARCH_PHYS_ADDR_T_64BIT
1110 def_bool X86_64 || X86_PAE
1112 config DIRECT_GBPAGES
1113 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1117 Allow the kernel linear mapping to use 1GB pages on CPUs that
1118 support it. This can improve the kernel's performance a tiny bit by
1119 reducing TLB pressure. If in doubt, say "Y".
1121 # Common NUMA Features
1123 bool "Numa Memory Allocation and Scheduler Support"
1125 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1126 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1128 Enable NUMA (Non Uniform Memory Access) support.
1130 The kernel will try to allocate memory used by a CPU on the
1131 local memory controller of the CPU and add some more
1132 NUMA awareness to the kernel.
1134 For 64-bit this is recommended if the system is Intel Core i7
1135 (or later), AMD Opteron, or EM64T NUMA.
1137 For 32-bit this is only needed on (rare) 32-bit-only platforms
1138 that support NUMA topologies, such as NUMAQ / Summit, or if you
1139 boot a 32-bit kernel on a 64-bit NUMA platform.
1141 Otherwise, you should say N.
1143 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1144 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1148 prompt "Old style AMD Opteron NUMA detection"
1149 depends on X86_64 && NUMA && PCI
1151 Enable K8 NUMA node topology detection. You should say Y here if
1152 you have a multi processor AMD K8 system. This uses an old
1153 method to read the NUMA configuration directly from the builtin
1154 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1155 instead, which also takes priority if both are compiled in.
1157 config X86_64_ACPI_NUMA
1159 prompt "ACPI NUMA detection"
1160 depends on X86_64 && NUMA && ACPI && PCI
1163 Enable ACPI SRAT based node topology detection.
1165 # Some NUMA nodes have memory ranges that span
1166 # other nodes. Even though a pfn is valid and
1167 # between a node's start and end pfns, it may not
1168 # reside on that node. See memmap_init_zone()
1170 config NODES_SPAN_OTHER_NODES
1172 depends on X86_64_ACPI_NUMA
1175 bool "NUMA emulation"
1176 depends on X86_64 && NUMA
1178 Enable NUMA emulation. A flat machine will be split
1179 into virtual nodes when booted with "numa=fake=N", where N is the
1180 number of nodes. This is only useful for debugging.
1183 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1185 default "9" if MAXSMP
1186 default "6" if X86_64
1187 default "4" if X86_NUMAQ
1189 depends on NEED_MULTIPLE_NODES
1191 Specify the maximum number of NUMA Nodes available on the target
1192 system. Increases memory reserved to accommodate various tables.
1194 config HAVE_ARCH_BOOTMEM
1196 depends on X86_32 && NUMA
1198 config ARCH_HAVE_MEMORY_PRESENT
1200 depends on X86_32 && DISCONTIGMEM
1202 config NEED_NODE_MEMMAP_SIZE
1204 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1206 config HAVE_ARCH_ALLOC_REMAP
1208 depends on X86_32 && NUMA
1210 config ARCH_FLATMEM_ENABLE
1212 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1214 config ARCH_DISCONTIGMEM_ENABLE
1216 depends on NUMA && X86_32
1218 config ARCH_DISCONTIGMEM_DEFAULT
1220 depends on NUMA && X86_32
1222 config ARCH_PROC_KCORE_TEXT
1224 depends on X86_64 && PROC_KCORE
1226 config ARCH_SPARSEMEM_DEFAULT
1230 config ARCH_SPARSEMEM_ENABLE
1232 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1233 select SPARSEMEM_STATIC if X86_32
1234 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1236 config ARCH_SELECT_MEMORY_MODEL
1238 depends on ARCH_SPARSEMEM_ENABLE
1240 config ARCH_MEMORY_PROBE
1242 depends on MEMORY_HOTPLUG
1244 config ILLEGAL_POINTER_VALUE
1247 default 0xdead000000000000 if X86_64
1252 bool "Allocate 3rd-level pagetables from highmem"
1253 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1255 The VM uses one page table entry for each page of physical memory.
1256 For systems with a lot of RAM, this can be wasteful of precious
1257 low memory. Setting this option will put user-space page table
1258 entries in high memory.
1260 config X86_CHECK_BIOS_CORRUPTION
1261 bool "Check for low memory corruption"
1263 Periodically check for memory corruption in low memory, which
1264 is suspected to be caused by BIOS. Even when enabled in the
1265 configuration, it is disabled at runtime. Enable it by
1266 setting "memory_corruption_check=1" on the kernel command
1267 line. By default it scans the low 64k of memory every 60
1268 seconds; see the memory_corruption_check_size and
1269 memory_corruption_check_period parameters in
1270 Documentation/kernel-parameters.txt to adjust this.
1272 When enabled with the default parameters, this option has
1273 almost no overhead, as it reserves a relatively small amount
1274 of memory and scans it infrequently. It both detects corruption
1275 and prevents it from affecting the running system.
1277 It is, however, intended as a diagnostic tool; if repeatable
1278 BIOS-originated corruption always affects the same memory,
1279 you can use memmap= to prevent the kernel from using that
1282 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1283 bool "Set the default setting of memory_corruption_check"
1284 depends on X86_CHECK_BIOS_CORRUPTION
1287 Set whether the default state of memory_corruption_check is
1290 config X86_RESERVE_LOW_64K
1291 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1294 Reserve the first 64K of physical RAM on BIOSes that are known
1295 to potentially corrupt that memory range. A numbers of BIOSes are
1296 known to utilize this area during suspend/resume, so it must not
1297 be used by the kernel.
1299 Set this to N if you are absolutely sure that you trust the BIOS
1300 to get all its memory reservations and usages right.
1302 If you have doubts about the BIOS (e.g. suspend/resume does not
1303 work or there's kernel crashes after certain hardware hotplug
1304 events) and it's not AMI or Phoenix, then you might want to enable
1305 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1306 corruption patterns.
1310 config MATH_EMULATION
1312 prompt "Math emulation" if X86_32
1314 Linux can emulate a math coprocessor (used for floating point
1315 operations) if you don't have one. 486DX and Pentium processors have
1316 a math coprocessor built in, 486SX and 386 do not, unless you added
1317 a 487DX or 387, respectively. (The messages during boot time can
1318 give you some hints here ["man dmesg"].) Everyone needs either a
1319 coprocessor or this emulation.
1321 If you don't have a math coprocessor, you need to say Y here; if you
1322 say Y here even though you have a coprocessor, the coprocessor will
1323 be used nevertheless. (This behavior can be changed with the kernel
1324 command line option "no387", which comes handy if your coprocessor
1325 is broken. Try "man bootparam" or see the documentation of your boot
1326 loader (lilo or loadlin) about how to pass options to the kernel at
1327 boot time.) This means that it is a good idea to say Y here if you
1328 intend to use this kernel on different machines.
1330 More information about the internals of the Linux math coprocessor
1331 emulation can be found in <file:arch/x86/math-emu/README>.
1333 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1334 kernel, it won't hurt.
1339 prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1341 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1342 the Memory Type Range Registers (MTRRs) may be used to control
1343 processor access to memory ranges. This is most useful if you have
1344 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1345 allows bus write transfers to be combined into a larger transfer
1346 before bursting over the PCI/AGP bus. This can increase performance
1347 of image write operations 2.5 times or more. Saying Y here creates a
1348 /proc/mtrr file which may be used to manipulate your processor's
1349 MTRRs. Typically the X server should use this.
1351 This code has a reasonably generic interface so that similar
1352 control registers on other processors can be easily supported
1355 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1356 Registers (ARRs) which provide a similar functionality to MTRRs. For
1357 these, the ARRs are used to emulate the MTRRs.
1358 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1359 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1360 write-combining. All of these processors are supported by this code
1361 and it makes sense to say Y here if you have one of them.
1363 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1364 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1365 can lead to all sorts of problems, so it's good to say Y here.
1367 You can safely say Y even if your machine doesn't have MTRRs, you'll
1368 just add about 9 KB to your kernel.
1370 See <file:Documentation/x86/mtrr.txt> for more information.
1372 config MTRR_SANITIZER
1374 prompt "MTRR cleanup support"
1377 Convert MTRR layout from continuous to discrete, so X drivers can
1378 add writeback entries.
1380 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1381 The largest mtrr entry size for a continuous block can be set with
1386 config MTRR_SANITIZER_ENABLE_DEFAULT
1387 int "MTRR cleanup enable value (0-1)"
1390 depends on MTRR_SANITIZER
1392 Enable mtrr cleanup default value
1394 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1395 int "MTRR cleanup spare reg num (0-7)"
1398 depends on MTRR_SANITIZER
1400 mtrr cleanup spare entries default, it can be changed via
1401 mtrr_spare_reg_nr=N on the kernel command line.
1406 prompt "x86 PAT support" if EMBEDDED
1409 Use PAT attributes to setup page level cache control.
1411 PATs are the modern equivalents of MTRRs and are much more
1412 flexible than MTRRs.
1414 Say N here if you see bootup problems (boot crash, boot hang,
1415 spontaneous reboots) or a non-working video driver.
1419 config ARCH_USES_PG_UNCACHED
1424 bool "EFI runtime service support"
1427 This enables the kernel to use EFI runtime services that are
1428 available (such as the EFI variable services).
1430 This option is only useful on systems that have EFI firmware.
1431 In addition, you should use the latest ELILO loader available
1432 at <http://elilo.sourceforge.net> in order to take advantage
1433 of EFI runtime services. However, even with this option, the
1434 resultant kernel should continue to boot on existing non-EFI
1439 prompt "Enable seccomp to safely compute untrusted bytecode"
1441 This kernel feature is useful for number crunching applications
1442 that may need to compute untrusted bytecode during their
1443 execution. By using pipes or other transports made available to
1444 the process as file descriptors supporting the read/write
1445 syscalls, it's possible to isolate those applications in
1446 their own address space using seccomp. Once seccomp is
1447 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1448 and the task is only allowed to execute a few safe syscalls
1449 defined by each seccomp mode.
1451 If unsure, say Y. Only embedded should say N here.
1453 config CC_STACKPROTECTOR
1454 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1456 This option turns on the -fstack-protector GCC feature. This
1457 feature puts, at the beginning of functions, a canary value on
1458 the stack just before the return address, and validates
1459 the value just before actually returning. Stack based buffer
1460 overflows (that need to overwrite this return address) now also
1461 overwrite the canary, which gets detected and the attack is then
1462 neutralized via a kernel panic.
1464 This feature requires gcc version 4.2 or above, or a distribution
1465 gcc with the feature backported. Older versions are automatically
1466 detected and for those versions, this configuration option is
1467 ignored. (and a warning is printed during bootup)
1469 source kernel/Kconfig.hz
1472 bool "kexec system call"
1474 kexec is a system call that implements the ability to shutdown your
1475 current kernel, and to start another kernel. It is like a reboot
1476 but it is independent of the system firmware. And like a reboot
1477 you can start any kernel with it, not just Linux.
1479 The name comes from the similarity to the exec system call.
1481 It is an ongoing process to be certain the hardware in a machine
1482 is properly shutdown, so do not be surprised if this code does not
1483 initially work for you. It may help to enable device hotplugging
1484 support. As of this writing the exact hardware interface is
1485 strongly in flux, so no good recommendation can be made.
1488 bool "kernel crash dumps"
1489 depends on X86_64 || (X86_32 && HIGHMEM)
1491 Generate crash dump after being started by kexec.
1492 This should be normally only set in special crash dump kernels
1493 which are loaded in the main kernel with kexec-tools into
1494 a specially reserved region and then later executed after
1495 a crash by kdump/kexec. The crash dump kernel must be compiled
1496 to a memory address not used by the main kernel or BIOS using
1497 PHYSICAL_START, or it must be built as a relocatable image
1498 (CONFIG_RELOCATABLE=y).
1499 For more details see Documentation/kdump/kdump.txt
1502 bool "kexec jump (EXPERIMENTAL)"
1503 depends on EXPERIMENTAL
1504 depends on KEXEC && HIBERNATION
1506 Jump between original kernel and kexeced kernel and invoke
1507 code in physical address mode via KEXEC
1509 config PHYSICAL_START
1510 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1513 This gives the physical address where the kernel is loaded.
1515 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1516 bzImage will decompress itself to above physical address and
1517 run from there. Otherwise, bzImage will run from the address where
1518 it has been loaded by the boot loader and will ignore above physical
1521 In normal kdump cases one does not have to set/change this option
1522 as now bzImage can be compiled as a completely relocatable image
1523 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1524 address. This option is mainly useful for the folks who don't want
1525 to use a bzImage for capturing the crash dump and want to use a
1526 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1527 to be specifically compiled to run from a specific memory area
1528 (normally a reserved region) and this option comes handy.
1530 So if you are using bzImage for capturing the crash dump,
1531 leave the value here unchanged to 0x1000000 and set
1532 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1533 for capturing the crash dump change this value to start of
1534 the reserved region. In other words, it can be set based on
1535 the "X" value as specified in the "crashkernel=YM@XM"
1536 command line boot parameter passed to the panic-ed
1537 kernel. Please take a look at Documentation/kdump/kdump.txt
1538 for more details about crash dumps.
1540 Usage of bzImage for capturing the crash dump is recommended as
1541 one does not have to build two kernels. Same kernel can be used
1542 as production kernel and capture kernel. Above option should have
1543 gone away after relocatable bzImage support is introduced. But it
1544 is present because there are users out there who continue to use
1545 vmlinux for dump capture. This option should go away down the
1548 Don't change this unless you know what you are doing.
1551 bool "Build a relocatable kernel"
1554 This builds a kernel image that retains relocation information
1555 so it can be loaded someplace besides the default 1MB.
1556 The relocations tend to make the kernel binary about 10% larger,
1557 but are discarded at runtime.
1559 One use is for the kexec on panic case where the recovery kernel
1560 must live at a different physical address than the primary
1563 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1564 it has been loaded at and the compile time physical address
1565 (CONFIG_PHYSICAL_START) is ignored.
1567 # Relocation on x86-32 needs some additional build support
1568 config X86_NEED_RELOCS
1570 depends on X86_32 && RELOCATABLE
1572 config PHYSICAL_ALIGN
1574 prompt "Alignment value to which kernel should be aligned" if X86_32
1576 range 0x2000 0x1000000
1578 This value puts the alignment restrictions on physical address
1579 where kernel is loaded and run from. Kernel is compiled for an
1580 address which meets above alignment restriction.
1582 If bootloader loads the kernel at a non-aligned address and
1583 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1584 address aligned to above value and run from there.
1586 If bootloader loads the kernel at a non-aligned address and
1587 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1588 load address and decompress itself to the address it has been
1589 compiled for and run from there. The address for which kernel is
1590 compiled already meets above alignment restrictions. Hence the
1591 end result is that kernel runs from a physical address meeting
1592 above alignment restrictions.
1594 Don't change this unless you know what you are doing.
1597 bool "Support for hot-pluggable CPUs"
1598 depends on SMP && HOTPLUG
1600 Say Y here to allow turning CPUs off and on. CPUs can be
1601 controlled through /sys/devices/system/cpu.
1602 ( Note: power management support will enable this option
1603 automatically on SMP systems. )
1604 Say N if you want to disable CPU hotplug.
1608 prompt "Compat VDSO support"
1609 depends on X86_32 || IA32_EMULATION
1611 Map the 32-bit VDSO to the predictable old-style address too.
1613 Say N here if you are running a sufficiently recent glibc
1614 version (2.3.3 or later), to remove the high-mapped
1615 VDSO mapping and to exclusively use the randomized VDSO.
1620 bool "Built-in kernel command line"
1623 Allow for specifying boot arguments to the kernel at
1624 build time. On some systems (e.g. embedded ones), it is
1625 necessary or convenient to provide some or all of the
1626 kernel boot arguments with the kernel itself (that is,
1627 to not rely on the boot loader to provide them.)
1629 To compile command line arguments into the kernel,
1630 set this option to 'Y', then fill in the
1631 the boot arguments in CONFIG_CMDLINE.
1633 Systems with fully functional boot loaders (i.e. non-embedded)
1634 should leave this option set to 'N'.
1637 string "Built-in kernel command string"
1638 depends on CMDLINE_BOOL
1641 Enter arguments here that should be compiled into the kernel
1642 image and used at boot time. If the boot loader provides a
1643 command line at boot time, it is appended to this string to
1644 form the full kernel command line, when the system boots.
1646 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1647 change this behavior.
1649 In most cases, the command line (whether built-in or provided
1650 by the boot loader) should specify the device for the root
1653 config CMDLINE_OVERRIDE
1654 bool "Built-in command line overrides boot loader arguments"
1656 depends on CMDLINE_BOOL
1658 Set this option to 'Y' to have the kernel ignore the boot loader
1659 command line, and use ONLY the built-in command line.
1661 This is used to work around broken boot loaders. This should
1662 be set to 'N' under normal conditions.
1666 config ARCH_ENABLE_MEMORY_HOTPLUG
1668 depends on X86_64 || (X86_32 && HIGHMEM)
1670 config ARCH_ENABLE_MEMORY_HOTREMOVE
1672 depends on MEMORY_HOTPLUG
1674 config HAVE_ARCH_EARLY_PFN_TO_NID
1678 menu "Power management and ACPI options"
1680 config ARCH_HIBERNATION_HEADER
1682 depends on X86_64 && HIBERNATION
1684 source "kernel/power/Kconfig"
1686 source "drivers/acpi/Kconfig"
1688 source "drivers/sfi/Kconfig"
1693 depends on APM || APM_MODULE
1696 tristate "APM (Advanced Power Management) BIOS support"
1697 depends on X86_32 && PM_SLEEP
1699 APM is a BIOS specification for saving power using several different
1700 techniques. This is mostly useful for battery powered laptops with
1701 APM compliant BIOSes. If you say Y here, the system time will be
1702 reset after a RESUME operation, the /proc/apm device will provide
1703 battery status information, and user-space programs will receive
1704 notification of APM "events" (e.g. battery status change).
1706 If you select "Y" here, you can disable actual use of the APM
1707 BIOS by passing the "apm=off" option to the kernel at boot time.
1709 Note that the APM support is almost completely disabled for
1710 machines with more than one CPU.
1712 In order to use APM, you will need supporting software. For location
1713 and more information, read <file:Documentation/power/pm.txt> and the
1714 Battery Powered Linux mini-HOWTO, available from
1715 <http://www.tldp.org/docs.html#howto>.
1717 This driver does not spin down disk drives (see the hdparm(8)
1718 manpage ("man 8 hdparm") for that), and it doesn't turn off
1719 VESA-compliant "green" monitors.
1721 This driver does not support the TI 4000M TravelMate and the ACER
1722 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1723 desktop machines also don't have compliant BIOSes, and this driver
1724 may cause those machines to panic during the boot phase.
1726 Generally, if you don't have a battery in your machine, there isn't
1727 much point in using this driver and you should say N. If you get
1728 random kernel OOPSes or reboots that don't seem to be related to
1729 anything, try disabling/enabling this option (or disabling/enabling
1732 Some other things you should try when experiencing seemingly random,
1735 1) make sure that you have enough swap space and that it is
1737 2) pass the "no-hlt" option to the kernel
1738 3) switch on floating point emulation in the kernel and pass
1739 the "no387" option to the kernel
1740 4) pass the "floppy=nodma" option to the kernel
1741 5) pass the "mem=4M" option to the kernel (thereby disabling
1742 all but the first 4 MB of RAM)
1743 6) make sure that the CPU is not over clocked.
1744 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1745 8) disable the cache from your BIOS settings
1746 9) install a fan for the video card or exchange video RAM
1747 10) install a better fan for the CPU
1748 11) exchange RAM chips
1749 12) exchange the motherboard.
1751 To compile this driver as a module, choose M here: the
1752 module will be called apm.
1756 config APM_IGNORE_USER_SUSPEND
1757 bool "Ignore USER SUSPEND"
1759 This option will ignore USER SUSPEND requests. On machines with a
1760 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1761 series notebooks, it is necessary to say Y because of a BIOS bug.
1763 config APM_DO_ENABLE
1764 bool "Enable PM at boot time"
1766 Enable APM features at boot time. From page 36 of the APM BIOS
1767 specification: "When disabled, the APM BIOS does not automatically
1768 power manage devices, enter the Standby State, enter the Suspend
1769 State, or take power saving steps in response to CPU Idle calls."
1770 This driver will make CPU Idle calls when Linux is idle (unless this
1771 feature is turned off -- see "Do CPU IDLE calls", below). This
1772 should always save battery power, but more complicated APM features
1773 will be dependent on your BIOS implementation. You may need to turn
1774 this option off if your computer hangs at boot time when using APM
1775 support, or if it beeps continuously instead of suspending. Turn
1776 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1777 T400CDT. This is off by default since most machines do fine without
1781 bool "Make CPU Idle calls when idle"
1783 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1784 On some machines, this can activate improved power savings, such as
1785 a slowed CPU clock rate, when the machine is idle. These idle calls
1786 are made after the idle loop has run for some length of time (e.g.,
1787 333 mS). On some machines, this will cause a hang at boot time or
1788 whenever the CPU becomes idle. (On machines with more than one CPU,
1789 this option does nothing.)
1791 config APM_DISPLAY_BLANK
1792 bool "Enable console blanking using APM"
1794 Enable console blanking using the APM. Some laptops can use this to
1795 turn off the LCD backlight when the screen blanker of the Linux
1796 virtual console blanks the screen. Note that this is only used by
1797 the virtual console screen blanker, and won't turn off the backlight
1798 when using the X Window system. This also doesn't have anything to
1799 do with your VESA-compliant power-saving monitor. Further, this
1800 option doesn't work for all laptops -- it might not turn off your
1801 backlight at all, or it might print a lot of errors to the console,
1802 especially if you are using gpm.
1804 config APM_ALLOW_INTS
1805 bool "Allow interrupts during APM BIOS calls"
1807 Normally we disable external interrupts while we are making calls to
1808 the APM BIOS as a measure to lessen the effects of a badly behaving
1809 BIOS implementation. The BIOS should reenable interrupts if it
1810 needs to. Unfortunately, some BIOSes do not -- especially those in
1811 many of the newer IBM Thinkpads. If you experience hangs when you
1812 suspend, try setting this to Y. Otherwise, say N.
1816 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1818 source "drivers/cpuidle/Kconfig"
1820 source "drivers/idle/Kconfig"
1825 menu "Bus options (PCI etc.)"
1830 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1832 Find out whether you have a PCI motherboard. PCI is the name of a
1833 bus system, i.e. the way the CPU talks to the other stuff inside
1834 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1835 VESA. If you have PCI, say Y, otherwise N.
1838 prompt "PCI access mode"
1839 depends on X86_32 && PCI
1842 On PCI systems, the BIOS can be used to detect the PCI devices and
1843 determine their configuration. However, some old PCI motherboards
1844 have BIOS bugs and may crash if this is done. Also, some embedded
1845 PCI-based systems don't have any BIOS at all. Linux can also try to
1846 detect the PCI hardware directly without using the BIOS.
1848 With this option, you can specify how Linux should detect the
1849 PCI devices. If you choose "BIOS", the BIOS will be used,
1850 if you choose "Direct", the BIOS won't be used, and if you
1851 choose "MMConfig", then PCI Express MMCONFIG will be used.
1852 If you choose "Any", the kernel will try MMCONFIG, then the
1853 direct access method and falls back to the BIOS if that doesn't
1854 work. If unsure, go with the default, which is "Any".
1859 config PCI_GOMMCONFIG
1876 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1878 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1881 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1885 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1889 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1896 bool "Support mmconfig PCI config space access"
1897 depends on X86_64 && PCI && ACPI
1900 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1901 depends on PCI_MSI && ACPI && EXPERIMENTAL
1903 DMA remapping (DMAR) devices support enables independent address
1904 translations for Direct Memory Access (DMA) from devices.
1905 These DMA remapping devices are reported via ACPI tables
1906 and include PCI device scope covered by these DMA
1909 config DMAR_DEFAULT_ON
1911 prompt "Enable DMA Remapping Devices by default"
1914 Selecting this option will enable a DMAR device at boot time if
1915 one is found. If this option is not selected, DMAR support can
1916 be enabled by passing intel_iommu=on to the kernel. It is
1917 recommended you say N here while the DMAR code remains
1920 config DMAR_BROKEN_GFX_WA
1922 prompt "Workaround broken graphics drivers (going away soon)"
1923 depends on DMAR && BROKEN
1925 Current Graphics drivers tend to use physical address
1926 for DMA and avoid using DMA APIs. Setting this config
1927 option permits the IOMMU driver to set a unity map for
1928 all the OS-visible memory. Hence the driver can continue
1929 to use physical addresses for DMA, at least until this
1930 option is removed in the 2.6.32 kernel.
1932 config DMAR_FLOPPY_WA
1936 Floppy disk drivers are known to bypass DMA API calls
1937 thereby failing to work when IOMMU is enabled. This
1938 workaround will setup a 1:1 mapping for the first
1939 16MiB to make floppy (an ISA device) work.
1942 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1943 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1945 Supports Interrupt remapping for IO-APIC and MSI devices.
1946 To use x2apic mode in the CPU's which support x2APIC enhancements or
1947 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1949 source "drivers/pci/pcie/Kconfig"
1951 source "drivers/pci/Kconfig"
1953 # x86_64 have no ISA slots, but do have ISA-style DMA.
1962 Find out whether you have ISA slots on your motherboard. ISA is the
1963 name of a bus system, i.e. the way the CPU talks to the other stuff
1964 inside your box. Other bus systems are PCI, EISA, MicroChannel
1965 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1966 newer boards don't support it. If you have ISA, say Y, otherwise N.
1972 The Extended Industry Standard Architecture (EISA) bus was
1973 developed as an open alternative to the IBM MicroChannel bus.
1975 The EISA bus provided some of the features of the IBM MicroChannel
1976 bus while maintaining backward compatibility with cards made for
1977 the older ISA bus. The EISA bus saw limited use between 1988 and
1978 1995 when it was made obsolete by the PCI bus.
1980 Say Y here if you are building a kernel for an EISA-based machine.
1984 source "drivers/eisa/Kconfig"
1989 MicroChannel Architecture is found in some IBM PS/2 machines and
1990 laptops. It is a bus system similar to PCI or ISA. See
1991 <file:Documentation/mca.txt> (and especially the web page given
1992 there) before attempting to build an MCA bus kernel.
1994 source "drivers/mca/Kconfig"
1997 tristate "NatSemi SCx200 support"
1999 This provides basic support for National Semiconductor's
2000 (now AMD's) Geode processors. The driver probes for the
2001 PCI-IDs of several on-chip devices, so its a good dependency
2002 for other scx200_* drivers.
2004 If compiled as a module, the driver is named scx200.
2006 config SCx200HR_TIMER
2007 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2008 depends on SCx200 && GENERIC_TIME
2011 This driver provides a clocksource built upon the on-chip
2012 27MHz high-resolution timer. Its also a workaround for
2013 NSC Geode SC-1100's buggy TSC, which loses time when the
2014 processor goes idle (as is done by the scheduler). The
2015 other workaround is idle=poll boot option.
2018 bool "One Laptop Per Child support"
2022 Add support for detecting the unique features of the OLPC
2029 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2031 source "drivers/pcmcia/Kconfig"
2033 source "drivers/pci/hotplug/Kconfig"
2038 menu "Executable file formats / Emulations"
2040 source "fs/Kconfig.binfmt"
2042 config IA32_EMULATION
2043 bool "IA32 Emulation"
2045 select COMPAT_BINFMT_ELF
2047 Include code to run 32-bit programs under a 64-bit kernel. You should
2048 likely turn this on, unless you're 100% sure that you don't have any
2049 32-bit programs left.
2052 tristate "IA32 a.out support"
2053 depends on IA32_EMULATION
2055 Support old a.out binaries in the 32bit emulation.
2059 depends on IA32_EMULATION
2061 config COMPAT_FOR_U64_ALIGNMENT
2065 config SYSVIPC_COMPAT
2067 depends on COMPAT && SYSVIPC
2072 config HAVE_ATOMIC_IOMAP
2076 source "net/Kconfig"
2078 source "drivers/Kconfig"
2080 source "drivers/firmware/Kconfig"
2084 source "arch/x86/Kconfig.debug"
2086 source "security/Kconfig"
2088 source "crypto/Kconfig"
2090 source "arch/x86/kvm/Kconfig"
2092 source "lib/Kconfig"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blob