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_ARCH_KMEMCHECK
56 default "elf32-i386" if X86_32
57 default "elf64-x86-64" if X86_64
61 default "arch/x86/configs/i386_defconfig" if X86_32
62 default "arch/x86/configs/x86_64_defconfig" if X86_64
67 config GENERIC_CMOS_UPDATE
70 config CLOCKSOURCE_WATCHDOG
73 config GENERIC_CLOCKEVENTS
76 config GENERIC_CLOCKEVENTS_BROADCAST
78 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
80 config LOCKDEP_SUPPORT
83 config STACKTRACE_SUPPORT
86 config HAVE_LATENCYTOP_SUPPORT
89 config FAST_CMPXCHG_LOCAL
102 config GENERIC_ISA_DMA
111 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
113 config GENERIC_BUG_RELATIVE_POINTERS
116 config GENERIC_HWEIGHT
122 config ARCH_MAY_HAVE_PC_FDC
125 config RWSEM_GENERIC_SPINLOCK
128 config RWSEM_XCHGADD_ALGORITHM
131 config ARCH_HAS_CPU_IDLE_WAIT
134 config GENERIC_CALIBRATE_DELAY
137 config GENERIC_TIME_VSYSCALL
141 config ARCH_HAS_CPU_RELAX
144 config ARCH_HAS_DEFAULT_IDLE
147 config ARCH_HAS_CACHE_LINE_SIZE
150 config HAVE_SETUP_PER_CPU_AREA
153 config NEED_PER_CPU_EMBED_FIRST_CHUNK
156 config NEED_PER_CPU_PAGE_FIRST_CHUNK
159 config HAVE_CPUMASK_OF_CPU_MAP
162 config ARCH_HIBERNATION_POSSIBLE
165 config ARCH_SUSPEND_POSSIBLE
172 config ARCH_POPULATES_NODE_MAP
179 config ARCH_SUPPORTS_OPTIMIZED_INLINING
182 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
185 config HAVE_INTEL_TXT
187 depends on EXPERIMENTAL && DMAR && ACPI
189 # Use the generic interrupt handling code in kernel/irq/:
190 config GENERIC_HARDIRQS
194 config GENERIC_HARDIRQS_NO__DO_IRQ
197 config GENERIC_IRQ_PROBE
201 config GENERIC_PENDING_IRQ
203 depends on GENERIC_HARDIRQS && SMP
206 config USE_GENERIC_SMP_HELPERS
212 depends on X86_32 && SMP
216 depends on X86_64 && SMP
223 config X86_TRAMPOLINE
225 depends on SMP || (64BIT && ACPI_SLEEP)
228 config X86_32_LAZY_GS
230 depends on X86_32 && !CC_STACKPROTECTOR
234 source "init/Kconfig"
235 source "kernel/Kconfig.freezer"
237 menu "Processor type and features"
239 source "kernel/time/Kconfig"
242 bool "Symmetric multi-processing support"
244 This enables support for systems with more than one CPU. If you have
245 a system with only one CPU, like most personal computers, say N. If
246 you have a system with more than one CPU, say Y.
248 If you say N here, the kernel will run on single and multiprocessor
249 machines, but will use only one CPU of a multiprocessor machine. If
250 you say Y here, the kernel will run on many, but not all,
251 singleprocessor machines. On a singleprocessor machine, the kernel
252 will run faster if you say N here.
254 Note that if you say Y here and choose architecture "586" or
255 "Pentium" under "Processor family", the kernel will not work on 486
256 architectures. Similarly, multiprocessor kernels for the "PPro"
257 architecture may not work on all Pentium based boards.
259 People using multiprocessor machines who say Y here should also say
260 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
261 Management" code will be disabled if you say Y here.
263 See also <file:Documentation/i386/IO-APIC.txt>,
264 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
265 <http://www.tldp.org/docs.html#howto>.
267 If you don't know what to do here, say N.
270 bool "Support x2apic"
271 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
273 This enables x2apic support on CPUs that have this feature.
275 This allows 32-bit apic IDs (so it can support very large systems),
276 and accesses the local apic via MSRs not via mmio.
278 If you don't know what to do here, say N.
281 bool "Support sparse irq numbering"
282 depends on PCI_MSI || HT_IRQ
284 This enables support for sparse irqs. This is useful for distro
285 kernels that want to define a high CONFIG_NR_CPUS value but still
286 want to have low kernel memory footprint on smaller machines.
288 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
289 out the irq_desc[] array in a more NUMA-friendly way. )
291 If you don't know what to do here, say N.
295 depends on SPARSE_IRQ && NUMA
298 bool "Enable MPS table" if ACPI
300 depends on X86_LOCAL_APIC
302 For old smp systems that do not have proper acpi support. Newer systems
303 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
306 bool "Support for big SMP systems with more than 8 CPUs"
307 depends on X86_32 && SMP
309 This option is needed for the systems that have more than 8 CPUs
312 config X86_EXTENDED_PLATFORM
313 bool "Support for extended (non-PC) x86 platforms"
316 If you disable this option then the kernel will only support
317 standard PC platforms. (which covers the vast majority of
320 If you enable this option then you'll be able to select support
321 for the following (non-PC) 32 bit x86 platforms:
325 SGI 320/540 (Visual Workstation)
326 Summit/EXA (IBM x440)
327 Unisys ES7000 IA32 series
328 Moorestown MID devices
330 If you have one of these systems, or if you want to build a
331 generic distribution kernel, say Y here - otherwise say N.
335 config X86_EXTENDED_PLATFORM
336 bool "Support for extended (non-PC) x86 platforms"
339 If you disable this option then the kernel will only support
340 standard PC platforms. (which covers the vast majority of
343 If you enable this option then you'll be able to select support
344 for the following (non-PC) 64 bit x86 platforms:
348 If you have one of these systems, or if you want to build a
349 generic distribution kernel, say Y here - otherwise say N.
351 # This is an alphabetically sorted list of 64 bit extended platforms
352 # Please maintain the alphabetic order if and when there are additions
357 depends on X86_64 && PCI
358 depends on X86_EXTENDED_PLATFORM
360 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
361 supposed to run on these EM64T-based machines. Only choose this option
362 if you have one of these machines.
365 bool "SGI Ultraviolet"
367 depends on X86_EXTENDED_PLATFORM
369 depends on X86_X2APIC
371 This option is needed in order to support SGI Ultraviolet systems.
372 If you don't have one of these, you should say N here.
374 # Following is an alphabetically sorted list of 32 bit extended platforms
375 # Please maintain the alphabetic order if and when there are additions
380 depends on X86_EXTENDED_PLATFORM
382 Select this for an AMD Elan processor.
384 Do not use this option for K6/Athlon/Opteron processors!
386 If unsure, choose "PC-compatible" instead.
389 bool "Moorestown MID platform"
391 depends on X86_EXTENDED_PLATFORM
393 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
394 Internet Device(MID) platform. Moorestown consists of two chips:
395 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
396 Unlike standard x86 PCs, Moorestown does not have many legacy devices
397 nor standard legacy replacement devices/features. e.g. Moorestown does
398 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
401 bool "RDC R-321x SoC"
403 depends on X86_EXTENDED_PLATFORM
405 select X86_REBOOTFIXUPS
407 This option is needed for RDC R-321x system-on-chip, also known
409 If you don't have one of these chips, you should say N here.
411 config X86_32_NON_STANDARD
412 bool "Support non-standard 32-bit SMP architectures"
413 depends on X86_32 && SMP
414 depends on X86_EXTENDED_PLATFORM
416 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
417 subarchitectures. It is intended for a generic binary kernel.
418 if you select them all, kernel will probe it one by one. and will
421 # Alphabetically sorted list of Non standard 32 bit platforms
424 bool "NUMAQ (IBM/Sequent)"
425 depends on X86_32_NON_STANDARD
429 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
430 NUMA multiquad box. This changes the way that processors are
431 bootstrapped, and uses Clustered Logical APIC addressing mode instead
432 of Flat Logical. You will need a new lynxer.elf file to flash your
433 firmware with - send email to <Martin.Bligh@us.ibm.com>.
435 config X86_SUPPORTS_MEMORY_FAILURE
437 # MCE code calls memory_failure():
439 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
440 depends on !X86_NUMAQ
441 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
442 depends on X86_64 || !SPARSEMEM
443 select ARCH_SUPPORTS_MEMORY_FAILURE
447 bool "SGI 320/540 (Visual Workstation)"
448 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
449 depends on X86_32_NON_STANDARD
451 The SGI Visual Workstation series is an IA32-based workstation
452 based on SGI systems chips with some legacy PC hardware attached.
454 Say Y here to create a kernel to run on the SGI 320 or 540.
456 A kernel compiled for the Visual Workstation will run on general
457 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
460 bool "Summit/EXA (IBM x440)"
461 depends on X86_32_NON_STANDARD
463 This option is needed for IBM systems that use the Summit/EXA chipset.
464 In particular, it is needed for the x440.
467 bool "Unisys ES7000 IA32 series"
468 depends on X86_32_NON_STANDARD && X86_BIGSMP
470 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
471 supposed to run on an IA32-based Unisys ES7000 system.
473 config SCHED_OMIT_FRAME_POINTER
475 prompt "Single-depth WCHAN output"
478 Calculate simpler /proc/<PID>/wchan values. If this option
479 is disabled then wchan values will recurse back to the
480 caller function. This provides more accurate wchan values,
481 at the expense of slightly more scheduling overhead.
483 If in doubt, say "Y".
485 menuconfig PARAVIRT_GUEST
486 bool "Paravirtualized guest support"
488 Say Y here to get to see options related to running Linux under
489 various hypervisors. This option alone does not add any kernel code.
491 If you say N, all options in this submenu will be skipped and disabled.
495 source "arch/x86/xen/Kconfig"
498 bool "VMI Guest support"
502 VMI provides a paravirtualized interface to the VMware ESX server
503 (it could be used by other hypervisors in theory too, but is not
504 at the moment), by linking the kernel to a GPL-ed ROM module
505 provided by the hypervisor.
508 bool "KVM paravirtualized clock"
510 select PARAVIRT_CLOCK
512 Turning on this option will allow you to run a paravirtualized clock
513 when running over the KVM hypervisor. Instead of relying on a PIT
514 (or probably other) emulation by the underlying device model, the host
515 provides the guest with timing infrastructure such as time of day, and
519 bool "KVM Guest support"
522 This option enables various optimizations for running under the KVM
525 source "arch/x86/lguest/Kconfig"
528 bool "Enable paravirtualization code"
530 This changes the kernel so it can modify itself when it is run
531 under a hypervisor, potentially improving performance significantly
532 over full virtualization. However, when run without a hypervisor
533 the kernel is theoretically slower and slightly larger.
535 config PARAVIRT_SPINLOCKS
536 bool "Paravirtualization layer for spinlocks"
537 depends on PARAVIRT && SMP && EXPERIMENTAL
539 Paravirtualized spinlocks allow a pvops backend to replace the
540 spinlock implementation with something virtualization-friendly
541 (for example, block the virtual CPU rather than spinning).
543 Unfortunately the downside is an up to 5% performance hit on
544 native kernels, with various workloads.
546 If you are unsure how to answer this question, answer N.
548 config PARAVIRT_CLOCK
554 config PARAVIRT_DEBUG
555 bool "paravirt-ops debugging"
556 depends on PARAVIRT && DEBUG_KERNEL
558 Enable to debug paravirt_ops internals. Specifically, BUG if
559 a paravirt_op is missing when it is called.
564 This option adds a kernel parameter 'memtest', which allows memtest
566 memtest=0, mean disabled; -- default
567 memtest=1, mean do 1 test pattern;
569 memtest=4, mean do 4 test patterns.
570 If you are unsure how to answer this question, answer N.
572 config X86_SUMMIT_NUMA
574 depends on X86_32 && NUMA && X86_32_NON_STANDARD
576 config X86_CYCLONE_TIMER
578 depends on X86_32_NON_STANDARD
580 source "arch/x86/Kconfig.cpu"
584 prompt "HPET Timer Support" if X86_32
586 Use the IA-PC HPET (High Precision Event Timer) to manage
587 time in preference to the PIT and RTC, if a HPET is
589 HPET is the next generation timer replacing legacy 8254s.
590 The HPET provides a stable time base on SMP
591 systems, unlike the TSC, but it is more expensive to access,
592 as it is off-chip. You can find the HPET spec at
593 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
595 You can safely choose Y here. However, HPET will only be
596 activated if the platform and the BIOS support this feature.
597 Otherwise the 8254 will be used for timing services.
599 Choose N to continue using the legacy 8254 timer.
601 config HPET_EMULATE_RTC
603 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
605 # Mark as embedded because too many people got it wrong.
606 # The code disables itself when not needed.
609 bool "Enable DMI scanning" if EMBEDDED
611 Enabled scanning of DMI to identify machine quirks. Say Y
612 here unless you have verified that your setup is not
613 affected by entries in the DMI blacklist. Required by PNP
617 bool "GART IOMMU support" if EMBEDDED
620 depends on X86_64 && PCI
622 Support for full DMA access of devices with 32bit memory access only
623 on systems with more than 3GB. This is usually needed for USB,
624 sound, many IDE/SATA chipsets and some other devices.
625 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
626 based hardware IOMMU and a software bounce buffer based IOMMU used
627 on Intel systems and as fallback.
628 The code is only active when needed (enough memory and limited
629 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
633 bool "IBM Calgary IOMMU support"
635 depends on X86_64 && PCI && EXPERIMENTAL
637 Support for hardware IOMMUs in IBM's xSeries x366 and x460
638 systems. Needed to run systems with more than 3GB of memory
639 properly with 32-bit PCI devices that do not support DAC
640 (Double Address Cycle). Calgary also supports bus level
641 isolation, where all DMAs pass through the IOMMU. This
642 prevents them from going anywhere except their intended
643 destination. This catches hard-to-find kernel bugs and
644 mis-behaving drivers and devices that do not use the DMA-API
645 properly to set up their DMA buffers. The IOMMU can be
646 turned off at boot time with the iommu=off parameter.
647 Normally the kernel will make the right choice by itself.
650 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
652 prompt "Should Calgary be enabled by default?"
653 depends on CALGARY_IOMMU
655 Should Calgary be enabled by default? if you choose 'y', Calgary
656 will be used (if it exists). If you choose 'n', Calgary will not be
657 used even if it exists. If you choose 'n' and would like to use
658 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
662 bool "AMD IOMMU support"
665 depends on X86_64 && PCI && ACPI
667 With this option you can enable support for AMD IOMMU hardware in
668 your system. An IOMMU is a hardware component which provides
669 remapping of DMA memory accesses from devices. With an AMD IOMMU you
670 can isolate the the DMA memory of different devices and protect the
671 system from misbehaving device drivers or hardware.
673 You can find out if your system has an AMD IOMMU if you look into
674 your BIOS for an option to enable it or if you have an IVRS ACPI
677 config AMD_IOMMU_STATS
678 bool "Export AMD IOMMU statistics to debugfs"
682 This option enables code in the AMD IOMMU driver to collect various
683 statistics about whats happening in the driver and exports that
684 information to userspace via debugfs.
687 # need this always selected by IOMMU for the VIA workaround
691 Support for software bounce buffers used on x86-64 systems
692 which don't have a hardware IOMMU (e.g. the current generation
693 of Intel's x86-64 CPUs). Using this PCI devices which can only
694 access 32-bits of memory can be used on systems with more than
695 3 GB of memory. If unsure, say Y.
698 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
701 def_bool (AMD_IOMMU || DMAR)
704 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
705 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
706 select CPUMASK_OFFSTACK
709 Configure maximum number of CPUS and NUMA Nodes for this architecture.
713 int "Maximum number of CPUs" if SMP && !MAXSMP
714 range 2 8 if SMP && X86_32 && !X86_BIGSMP
715 range 2 512 if SMP && !MAXSMP
717 default "4096" if MAXSMP
718 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
721 This allows you to specify the maximum number of CPUs which this
722 kernel will support. The maximum supported value is 512 and the
723 minimum value which makes sense is 2.
725 This is purely to save memory - each supported CPU adds
726 approximately eight kilobytes to the kernel image.
729 bool "SMT (Hyperthreading) scheduler support"
732 SMT scheduler support improves the CPU scheduler's decision making
733 when dealing with Intel Pentium 4 chips with HyperThreading at a
734 cost of slightly increased overhead in some places. If unsure say
739 prompt "Multi-core scheduler support"
742 Multi-core scheduler support improves the CPU scheduler's decision
743 making when dealing with multi-core CPU chips at a cost of slightly
744 increased overhead in some places. If unsure say N here.
746 source "kernel/Kconfig.preempt"
749 bool "Local APIC support on uniprocessors"
750 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
752 A local APIC (Advanced Programmable Interrupt Controller) is an
753 integrated interrupt controller in the CPU. If you have a single-CPU
754 system which has a processor with a local APIC, you can say Y here to
755 enable and use it. If you say Y here even though your machine doesn't
756 have a local APIC, then the kernel will still run with no slowdown at
757 all. The local APIC supports CPU-generated self-interrupts (timer,
758 performance counters), and the NMI watchdog which detects hard
762 bool "IO-APIC support on uniprocessors"
763 depends on X86_UP_APIC
765 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
766 SMP-capable replacement for PC-style interrupt controllers. Most
767 SMP systems and many recent uniprocessor systems have one.
769 If you have a single-CPU system with an IO-APIC, you can say Y here
770 to use it. If you say Y here even though your machine doesn't have
771 an IO-APIC, then the kernel will still run with no slowdown at all.
773 config X86_LOCAL_APIC
775 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
779 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
781 config X86_VISWS_APIC
783 depends on X86_32 && X86_VISWS
785 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
786 bool "Reroute for broken boot IRQs"
788 depends on X86_IO_APIC
790 This option enables a workaround that fixes a source of
791 spurious interrupts. This is recommended when threaded
792 interrupt handling is used on systems where the generation of
793 superfluous "boot interrupts" cannot be disabled.
795 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
796 entry in the chipset's IO-APIC is masked (as, e.g. the RT
797 kernel does during interrupt handling). On chipsets where this
798 boot IRQ generation cannot be disabled, this workaround keeps
799 the original IRQ line masked so that only the equivalent "boot
800 IRQ" is delivered to the CPUs. The workaround also tells the
801 kernel to set up the IRQ handler on the boot IRQ line. In this
802 way only one interrupt is delivered to the kernel. Otherwise
803 the spurious second interrupt may cause the kernel to bring
804 down (vital) interrupt lines.
806 Only affects "broken" chipsets. Interrupt sharing may be
807 increased on these systems.
810 bool "Machine Check / overheating reporting"
812 Machine Check support allows the processor to notify the
813 kernel if it detects a problem (e.g. overheating, data corruption).
814 The action the kernel takes depends on the severity of the problem,
815 ranging from warning messages to halting the machine.
819 prompt "Intel MCE features"
820 depends on X86_MCE && X86_LOCAL_APIC
822 Additional support for intel specific MCE features such as
827 prompt "AMD MCE features"
828 depends on X86_MCE && X86_LOCAL_APIC
830 Additional support for AMD specific MCE features such as
831 the DRAM Error Threshold.
833 config X86_ANCIENT_MCE
835 depends on X86_32 && X86_MCE
836 prompt "Support for old Pentium 5 / WinChip machine checks"
838 Include support for machine check handling on old Pentium 5 or WinChip
839 systems. These typically need to be enabled explicitely on the command
842 config X86_MCE_THRESHOLD
843 depends on X86_MCE_AMD || X86_MCE_INTEL
847 config X86_MCE_INJECT
849 tristate "Machine check injector support"
851 Provide support for injecting machine checks for testing purposes.
852 If you don't know what a machine check is and you don't do kernel
853 QA it is safe to say n.
855 config X86_THERMAL_VECTOR
857 depends on X86_MCE_INTEL
860 bool "Enable VM86 support" if EMBEDDED
864 This option is required by programs like DOSEMU to run 16-bit legacy
865 code on X86 processors. It also may be needed by software like
866 XFree86 to initialize some video cards via BIOS. Disabling this
867 option saves about 6k.
870 tristate "Toshiba Laptop support"
873 This adds a driver to safely access the System Management Mode of
874 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
875 not work on models with a Phoenix BIOS. The System Management Mode
876 is used to set the BIOS and power saving options on Toshiba portables.
878 For information on utilities to make use of this driver see the
879 Toshiba Linux utilities web site at:
880 <http://www.buzzard.org.uk/toshiba/>.
882 Say Y if you intend to run this kernel on a Toshiba portable.
886 tristate "Dell laptop support"
888 This adds a driver to safely access the System Management Mode
889 of the CPU on the Dell Inspiron 8000. The System Management Mode
890 is used to read cpu temperature and cooling fan status and to
891 control the fans on the I8K portables.
893 This driver has been tested only on the Inspiron 8000 but it may
894 also work with other Dell laptops. You can force loading on other
895 models by passing the parameter `force=1' to the module. Use at
898 For information on utilities to make use of this driver see the
899 I8K Linux utilities web site at:
900 <http://people.debian.org/~dz/i8k/>
902 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
905 config X86_REBOOTFIXUPS
906 bool "Enable X86 board specific fixups for reboot"
909 This enables chipset and/or board specific fixups to be done
910 in order to get reboot to work correctly. This is only needed on
911 some combinations of hardware and BIOS. The symptom, for which
912 this config is intended, is when reboot ends with a stalled/hung
915 Currently, the only fixup is for the Geode machines using
916 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
918 Say Y if you want to enable the fixup. Currently, it's safe to
919 enable this option even if you don't need it.
923 tristate "/dev/cpu/microcode - microcode support"
926 If you say Y here, you will be able to update the microcode on
927 certain Intel and AMD processors. The Intel support is for the
928 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
929 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
930 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
931 You will obviously need the actual microcode binary data itself
932 which is not shipped with the Linux kernel.
934 This option selects the general module only, you need to select
935 at least one vendor specific module as well.
937 To compile this driver as a module, choose M here: the
938 module will be called microcode.
940 config MICROCODE_INTEL
941 bool "Intel microcode patch loading support"
946 This options enables microcode patch loading support for Intel
949 For latest news and information on obtaining all the required
950 Intel ingredients for this driver, check:
951 <http://www.urbanmyth.org/microcode/>.
954 bool "AMD microcode patch loading support"
958 If you select this option, microcode patch loading support for AMD
959 processors will be enabled.
961 config MICROCODE_OLD_INTERFACE
966 tristate "/dev/cpu/*/msr - Model-specific register support"
968 This device gives privileged processes access to the x86
969 Model-Specific Registers (MSRs). It is a character device with
970 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
971 MSR accesses are directed to a specific CPU on multi-processor
975 tristate "/dev/cpu/*/cpuid - CPU information support"
977 This device gives processes access to the x86 CPUID instruction to
978 be executed on a specific processor. It is a character device
979 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
983 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
985 If you select this option, this will provide various x86 CPUs
986 information through debugfs.
989 prompt "High Memory Support"
990 default HIGHMEM4G if !X86_NUMAQ
991 default HIGHMEM64G if X86_NUMAQ
996 depends on !X86_NUMAQ
998 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
999 However, the address space of 32-bit x86 processors is only 4
1000 Gigabytes large. That means that, if you have a large amount of
1001 physical memory, not all of it can be "permanently mapped" by the
1002 kernel. The physical memory that's not permanently mapped is called
1005 If you are compiling a kernel which will never run on a machine with
1006 more than 1 Gigabyte total physical RAM, answer "off" here (default
1007 choice and suitable for most users). This will result in a "3GB/1GB"
1008 split: 3GB are mapped so that each process sees a 3GB virtual memory
1009 space and the remaining part of the 4GB virtual memory space is used
1010 by the kernel to permanently map as much physical memory as
1013 If the machine has between 1 and 4 Gigabytes physical RAM, then
1016 If more than 4 Gigabytes is used then answer "64GB" here. This
1017 selection turns Intel PAE (Physical Address Extension) mode on.
1018 PAE implements 3-level paging on IA32 processors. PAE is fully
1019 supported by Linux, PAE mode is implemented on all recent Intel
1020 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1021 then the kernel will not boot on CPUs that don't support PAE!
1023 The actual amount of total physical memory will either be
1024 auto detected or can be forced by using a kernel command line option
1025 such as "mem=256M". (Try "man bootparam" or see the documentation of
1026 your boot loader (lilo or loadlin) about how to pass options to the
1027 kernel at boot time.)
1029 If unsure, say "off".
1033 depends on !X86_NUMAQ
1035 Select this if you have a 32-bit processor and between 1 and 4
1036 gigabytes of physical RAM.
1040 depends on !M386 && !M486
1043 Select this if you have a 32-bit processor and more than 4
1044 gigabytes of physical RAM.
1049 depends on EXPERIMENTAL
1050 prompt "Memory split" if EMBEDDED
1054 Select the desired split between kernel and user memory.
1056 If the address range available to the kernel is less than the
1057 physical memory installed, the remaining memory will be available
1058 as "high memory". Accessing high memory is a little more costly
1059 than low memory, as it needs to be mapped into the kernel first.
1060 Note that increasing the kernel address space limits the range
1061 available to user programs, making the address space there
1062 tighter. Selecting anything other than the default 3G/1G split
1063 will also likely make your kernel incompatible with binary-only
1066 If you are not absolutely sure what you are doing, leave this
1070 bool "3G/1G user/kernel split"
1071 config VMSPLIT_3G_OPT
1073 bool "3G/1G user/kernel split (for full 1G low memory)"
1075 bool "2G/2G user/kernel split"
1076 config VMSPLIT_2G_OPT
1078 bool "2G/2G user/kernel split (for full 2G low memory)"
1080 bool "1G/3G user/kernel split"
1085 default 0xB0000000 if VMSPLIT_3G_OPT
1086 default 0x80000000 if VMSPLIT_2G
1087 default 0x78000000 if VMSPLIT_2G_OPT
1088 default 0x40000000 if VMSPLIT_1G
1094 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1097 bool "PAE (Physical Address Extension) Support"
1098 depends on X86_32 && !HIGHMEM4G
1100 PAE is required for NX support, and furthermore enables
1101 larger swapspace support for non-overcommit purposes. It
1102 has the cost of more pagetable lookup overhead, and also
1103 consumes more pagetable space per process.
1105 config ARCH_PHYS_ADDR_T_64BIT
1106 def_bool X86_64 || X86_PAE
1108 config DIRECT_GBPAGES
1109 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1113 Allow the kernel linear mapping to use 1GB pages on CPUs that
1114 support it. This can improve the kernel's performance a tiny bit by
1115 reducing TLB pressure. If in doubt, say "Y".
1117 # Common NUMA Features
1119 bool "Numa Memory Allocation and Scheduler Support"
1121 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1122 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1124 Enable NUMA (Non Uniform Memory Access) support.
1126 The kernel will try to allocate memory used by a CPU on the
1127 local memory controller of the CPU and add some more
1128 NUMA awareness to the kernel.
1130 For 64-bit this is recommended if the system is Intel Core i7
1131 (or later), AMD Opteron, or EM64T NUMA.
1133 For 32-bit this is only needed on (rare) 32-bit-only platforms
1134 that support NUMA topologies, such as NUMAQ / Summit, or if you
1135 boot a 32-bit kernel on a 64-bit NUMA platform.
1137 Otherwise, you should say N.
1139 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1140 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1144 prompt "Old style AMD Opteron NUMA detection"
1145 depends on X86_64 && NUMA && PCI
1147 Enable K8 NUMA node topology detection. You should say Y here if
1148 you have a multi processor AMD K8 system. This uses an old
1149 method to read the NUMA configuration directly from the builtin
1150 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1151 instead, which also takes priority if both are compiled in.
1153 config X86_64_ACPI_NUMA
1155 prompt "ACPI NUMA detection"
1156 depends on X86_64 && NUMA && ACPI && PCI
1159 Enable ACPI SRAT based node topology detection.
1161 # Some NUMA nodes have memory ranges that span
1162 # other nodes. Even though a pfn is valid and
1163 # between a node's start and end pfns, it may not
1164 # reside on that node. See memmap_init_zone()
1166 config NODES_SPAN_OTHER_NODES
1168 depends on X86_64_ACPI_NUMA
1171 bool "NUMA emulation"
1172 depends on X86_64 && NUMA
1174 Enable NUMA emulation. A flat machine will be split
1175 into virtual nodes when booted with "numa=fake=N", where N is the
1176 number of nodes. This is only useful for debugging.
1179 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1181 default "9" if MAXSMP
1182 default "6" if X86_64
1183 default "4" if X86_NUMAQ
1185 depends on NEED_MULTIPLE_NODES
1187 Specify the maximum number of NUMA Nodes available on the target
1188 system. Increases memory reserved to accommodate various tables.
1190 config HAVE_ARCH_BOOTMEM
1192 depends on X86_32 && NUMA
1194 config ARCH_HAVE_MEMORY_PRESENT
1196 depends on X86_32 && DISCONTIGMEM
1198 config NEED_NODE_MEMMAP_SIZE
1200 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1202 config HAVE_ARCH_ALLOC_REMAP
1204 depends on X86_32 && NUMA
1206 config ARCH_FLATMEM_ENABLE
1208 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1210 config ARCH_DISCONTIGMEM_ENABLE
1212 depends on NUMA && X86_32
1214 config ARCH_DISCONTIGMEM_DEFAULT
1216 depends on NUMA && X86_32
1218 config ARCH_PROC_KCORE_TEXT
1220 depends on X86_64 && PROC_KCORE
1222 config ARCH_SPARSEMEM_DEFAULT
1226 config ARCH_SPARSEMEM_ENABLE
1228 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1229 select SPARSEMEM_STATIC if X86_32
1230 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1232 config ARCH_SELECT_MEMORY_MODEL
1234 depends on ARCH_SPARSEMEM_ENABLE
1236 config ARCH_MEMORY_PROBE
1238 depends on MEMORY_HOTPLUG
1243 bool "Allocate 3rd-level pagetables from highmem"
1244 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1246 The VM uses one page table entry for each page of physical memory.
1247 For systems with a lot of RAM, this can be wasteful of precious
1248 low memory. Setting this option will put user-space page table
1249 entries in high memory.
1251 config X86_CHECK_BIOS_CORRUPTION
1252 bool "Check for low memory corruption"
1254 Periodically check for memory corruption in low memory, which
1255 is suspected to be caused by BIOS. Even when enabled in the
1256 configuration, it is disabled at runtime. Enable it by
1257 setting "memory_corruption_check=1" on the kernel command
1258 line. By default it scans the low 64k of memory every 60
1259 seconds; see the memory_corruption_check_size and
1260 memory_corruption_check_period parameters in
1261 Documentation/kernel-parameters.txt to adjust this.
1263 When enabled with the default parameters, this option has
1264 almost no overhead, as it reserves a relatively small amount
1265 of memory and scans it infrequently. It both detects corruption
1266 and prevents it from affecting the running system.
1268 It is, however, intended as a diagnostic tool; if repeatable
1269 BIOS-originated corruption always affects the same memory,
1270 you can use memmap= to prevent the kernel from using that
1273 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1274 bool "Set the default setting of memory_corruption_check"
1275 depends on X86_CHECK_BIOS_CORRUPTION
1278 Set whether the default state of memory_corruption_check is
1281 config X86_RESERVE_LOW_64K
1282 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1285 Reserve the first 64K of physical RAM on BIOSes that are known
1286 to potentially corrupt that memory range. A numbers of BIOSes are
1287 known to utilize this area during suspend/resume, so it must not
1288 be used by the kernel.
1290 Set this to N if you are absolutely sure that you trust the BIOS
1291 to get all its memory reservations and usages right.
1293 If you have doubts about the BIOS (e.g. suspend/resume does not
1294 work or there's kernel crashes after certain hardware hotplug
1295 events) and it's not AMI or Phoenix, then you might want to enable
1296 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1297 corruption patterns.
1301 config MATH_EMULATION
1303 prompt "Math emulation" if X86_32
1305 Linux can emulate a math coprocessor (used for floating point
1306 operations) if you don't have one. 486DX and Pentium processors have
1307 a math coprocessor built in, 486SX and 386 do not, unless you added
1308 a 487DX or 387, respectively. (The messages during boot time can
1309 give you some hints here ["man dmesg"].) Everyone needs either a
1310 coprocessor or this emulation.
1312 If you don't have a math coprocessor, you need to say Y here; if you
1313 say Y here even though you have a coprocessor, the coprocessor will
1314 be used nevertheless. (This behavior can be changed with the kernel
1315 command line option "no387", which comes handy if your coprocessor
1316 is broken. Try "man bootparam" or see the documentation of your boot
1317 loader (lilo or loadlin) about how to pass options to the kernel at
1318 boot time.) This means that it is a good idea to say Y here if you
1319 intend to use this kernel on different machines.
1321 More information about the internals of the Linux math coprocessor
1322 emulation can be found in <file:arch/x86/math-emu/README>.
1324 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1325 kernel, it won't hurt.
1328 bool "MTRR (Memory Type Range Register) support"
1330 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1331 the Memory Type Range Registers (MTRRs) may be used to control
1332 processor access to memory ranges. This is most useful if you have
1333 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1334 allows bus write transfers to be combined into a larger transfer
1335 before bursting over the PCI/AGP bus. This can increase performance
1336 of image write operations 2.5 times or more. Saying Y here creates a
1337 /proc/mtrr file which may be used to manipulate your processor's
1338 MTRRs. Typically the X server should use this.
1340 This code has a reasonably generic interface so that similar
1341 control registers on other processors can be easily supported
1344 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1345 Registers (ARRs) which provide a similar functionality to MTRRs. For
1346 these, the ARRs are used to emulate the MTRRs.
1347 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1348 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1349 write-combining. All of these processors are supported by this code
1350 and it makes sense to say Y here if you have one of them.
1352 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1353 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1354 can lead to all sorts of problems, so it's good to say Y here.
1356 You can safely say Y even if your machine doesn't have MTRRs, you'll
1357 just add about 9 KB to your kernel.
1359 See <file:Documentation/x86/mtrr.txt> for more information.
1361 config MTRR_SANITIZER
1363 prompt "MTRR cleanup support"
1366 Convert MTRR layout from continuous to discrete, so X drivers can
1367 add writeback entries.
1369 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1370 The largest mtrr entry size for a continuous block can be set with
1375 config MTRR_SANITIZER_ENABLE_DEFAULT
1376 int "MTRR cleanup enable value (0-1)"
1379 depends on MTRR_SANITIZER
1381 Enable mtrr cleanup default value
1383 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1384 int "MTRR cleanup spare reg num (0-7)"
1387 depends on MTRR_SANITIZER
1389 mtrr cleanup spare entries default, it can be changed via
1390 mtrr_spare_reg_nr=N on the kernel command line.
1394 prompt "x86 PAT support"
1397 Use PAT attributes to setup page level cache control.
1399 PATs are the modern equivalents of MTRRs and are much more
1400 flexible than MTRRs.
1402 Say N here if you see bootup problems (boot crash, boot hang,
1403 spontaneous reboots) or a non-working video driver.
1407 config ARCH_USES_PG_UNCACHED
1412 bool "EFI runtime service support"
1415 This enables the kernel to use EFI runtime services that are
1416 available (such as the EFI variable services).
1418 This option is only useful on systems that have EFI firmware.
1419 In addition, you should use the latest ELILO loader available
1420 at <http://elilo.sourceforge.net> in order to take advantage
1421 of EFI runtime services. However, even with this option, the
1422 resultant kernel should continue to boot on existing non-EFI
1427 prompt "Enable seccomp to safely compute untrusted bytecode"
1429 This kernel feature is useful for number crunching applications
1430 that may need to compute untrusted bytecode during their
1431 execution. By using pipes or other transports made available to
1432 the process as file descriptors supporting the read/write
1433 syscalls, it's possible to isolate those applications in
1434 their own address space using seccomp. Once seccomp is
1435 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1436 and the task is only allowed to execute a few safe syscalls
1437 defined by each seccomp mode.
1439 If unsure, say Y. Only embedded should say N here.
1441 config CC_STACKPROTECTOR_ALL
1444 config CC_STACKPROTECTOR
1445 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1446 select CC_STACKPROTECTOR_ALL
1448 This option turns on the -fstack-protector GCC feature. This
1449 feature puts, at the beginning of functions, a canary value on
1450 the stack just before the return address, and validates
1451 the value just before actually returning. Stack based buffer
1452 overflows (that need to overwrite this return address) now also
1453 overwrite the canary, which gets detected and the attack is then
1454 neutralized via a kernel panic.
1456 This feature requires gcc version 4.2 or above, or a distribution
1457 gcc with the feature backported. Older versions are automatically
1458 detected and for those versions, this configuration option is
1459 ignored. (and a warning is printed during bootup)
1461 source kernel/Kconfig.hz
1464 bool "kexec system call"
1466 kexec is a system call that implements the ability to shutdown your
1467 current kernel, and to start another kernel. It is like a reboot
1468 but it is independent of the system firmware. And like a reboot
1469 you can start any kernel with it, not just Linux.
1471 The name comes from the similarity to the exec system call.
1473 It is an ongoing process to be certain the hardware in a machine
1474 is properly shutdown, so do not be surprised if this code does not
1475 initially work for you. It may help to enable device hotplugging
1476 support. As of this writing the exact hardware interface is
1477 strongly in flux, so no good recommendation can be made.
1480 bool "kernel crash dumps"
1481 depends on X86_64 || (X86_32 && HIGHMEM)
1483 Generate crash dump after being started by kexec.
1484 This should be normally only set in special crash dump kernels
1485 which are loaded in the main kernel with kexec-tools into
1486 a specially reserved region and then later executed after
1487 a crash by kdump/kexec. The crash dump kernel must be compiled
1488 to a memory address not used by the main kernel or BIOS using
1489 PHYSICAL_START, or it must be built as a relocatable image
1490 (CONFIG_RELOCATABLE=y).
1491 For more details see Documentation/kdump/kdump.txt
1494 bool "kexec jump (EXPERIMENTAL)"
1495 depends on EXPERIMENTAL
1496 depends on KEXEC && HIBERNATION
1498 Jump between original kernel and kexeced kernel and invoke
1499 code in physical address mode via KEXEC
1501 config PHYSICAL_START
1502 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1505 This gives the physical address where the kernel is loaded.
1507 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1508 bzImage will decompress itself to above physical address and
1509 run from there. Otherwise, bzImage will run from the address where
1510 it has been loaded by the boot loader and will ignore above physical
1513 In normal kdump cases one does not have to set/change this option
1514 as now bzImage can be compiled as a completely relocatable image
1515 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1516 address. This option is mainly useful for the folks who don't want
1517 to use a bzImage for capturing the crash dump and want to use a
1518 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1519 to be specifically compiled to run from a specific memory area
1520 (normally a reserved region) and this option comes handy.
1522 So if you are using bzImage for capturing the crash dump,
1523 leave the value here unchanged to 0x1000000 and set
1524 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1525 for capturing the crash dump change this value to start of
1526 the reserved region. In other words, it can be set based on
1527 the "X" value as specified in the "crashkernel=YM@XM"
1528 command line boot parameter passed to the panic-ed
1529 kernel. Please take a look at Documentation/kdump/kdump.txt
1530 for more details about crash dumps.
1532 Usage of bzImage for capturing the crash dump is recommended as
1533 one does not have to build two kernels. Same kernel can be used
1534 as production kernel and capture kernel. Above option should have
1535 gone away after relocatable bzImage support is introduced. But it
1536 is present because there are users out there who continue to use
1537 vmlinux for dump capture. This option should go away down the
1540 Don't change this unless you know what you are doing.
1543 bool "Build a relocatable kernel"
1546 This builds a kernel image that retains relocation information
1547 so it can be loaded someplace besides the default 1MB.
1548 The relocations tend to make the kernel binary about 10% larger,
1549 but are discarded at runtime.
1551 One use is for the kexec on panic case where the recovery kernel
1552 must live at a different physical address than the primary
1555 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1556 it has been loaded at and the compile time physical address
1557 (CONFIG_PHYSICAL_START) is ignored.
1559 # Relocation on x86-32 needs some additional build support
1560 config X86_NEED_RELOCS
1562 depends on X86_32 && RELOCATABLE
1564 config PHYSICAL_ALIGN
1566 prompt "Alignment value to which kernel should be aligned" if X86_32
1568 range 0x2000 0x1000000
1570 This value puts the alignment restrictions on physical address
1571 where kernel is loaded and run from. Kernel is compiled for an
1572 address which meets above alignment restriction.
1574 If bootloader loads the kernel at a non-aligned address and
1575 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1576 address aligned to above value and run from there.
1578 If bootloader loads the kernel at a non-aligned address and
1579 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1580 load address and decompress itself to the address it has been
1581 compiled for and run from there. The address for which kernel is
1582 compiled already meets above alignment restrictions. Hence the
1583 end result is that kernel runs from a physical address meeting
1584 above alignment restrictions.
1586 Don't change this unless you know what you are doing.
1589 bool "Support for hot-pluggable CPUs"
1590 depends on SMP && HOTPLUG
1592 Say Y here to allow turning CPUs off and on. CPUs can be
1593 controlled through /sys/devices/system/cpu.
1594 ( Note: power management support will enable this option
1595 automatically on SMP systems. )
1596 Say N if you want to disable CPU hotplug.
1600 prompt "Compat VDSO support"
1601 depends on X86_32 || IA32_EMULATION
1603 Map the 32-bit VDSO to the predictable old-style address too.
1605 Say N here if you are running a sufficiently recent glibc
1606 version (2.3.3 or later), to remove the high-mapped
1607 VDSO mapping and to exclusively use the randomized VDSO.
1612 bool "Built-in kernel command line"
1615 Allow for specifying boot arguments to the kernel at
1616 build time. On some systems (e.g. embedded ones), it is
1617 necessary or convenient to provide some or all of the
1618 kernel boot arguments with the kernel itself (that is,
1619 to not rely on the boot loader to provide them.)
1621 To compile command line arguments into the kernel,
1622 set this option to 'Y', then fill in the
1623 the boot arguments in CONFIG_CMDLINE.
1625 Systems with fully functional boot loaders (i.e. non-embedded)
1626 should leave this option set to 'N'.
1629 string "Built-in kernel command string"
1630 depends on CMDLINE_BOOL
1633 Enter arguments here that should be compiled into the kernel
1634 image and used at boot time. If the boot loader provides a
1635 command line at boot time, it is appended to this string to
1636 form the full kernel command line, when the system boots.
1638 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1639 change this behavior.
1641 In most cases, the command line (whether built-in or provided
1642 by the boot loader) should specify the device for the root
1645 config CMDLINE_OVERRIDE
1646 bool "Built-in command line overrides boot loader arguments"
1648 depends on CMDLINE_BOOL
1650 Set this option to 'Y' to have the kernel ignore the boot loader
1651 command line, and use ONLY the built-in command line.
1653 This is used to work around broken boot loaders. This should
1654 be set to 'N' under normal conditions.
1658 config ARCH_ENABLE_MEMORY_HOTPLUG
1660 depends on X86_64 || (X86_32 && HIGHMEM)
1662 config ARCH_ENABLE_MEMORY_HOTREMOVE
1664 depends on MEMORY_HOTPLUG
1666 config HAVE_ARCH_EARLY_PFN_TO_NID
1670 menu "Power management and ACPI options"
1672 config ARCH_HIBERNATION_HEADER
1674 depends on X86_64 && HIBERNATION
1676 source "kernel/power/Kconfig"
1678 source "drivers/acpi/Kconfig"
1680 source "drivers/sfi/Kconfig"
1685 depends on APM || APM_MODULE
1688 tristate "APM (Advanced Power Management) BIOS support"
1689 depends on X86_32 && PM_SLEEP
1691 APM is a BIOS specification for saving power using several different
1692 techniques. This is mostly useful for battery powered laptops with
1693 APM compliant BIOSes. If you say Y here, the system time will be
1694 reset after a RESUME operation, the /proc/apm device will provide
1695 battery status information, and user-space programs will receive
1696 notification of APM "events" (e.g. battery status change).
1698 If you select "Y" here, you can disable actual use of the APM
1699 BIOS by passing the "apm=off" option to the kernel at boot time.
1701 Note that the APM support is almost completely disabled for
1702 machines with more than one CPU.
1704 In order to use APM, you will need supporting software. For location
1705 and more information, read <file:Documentation/power/pm.txt> and the
1706 Battery Powered Linux mini-HOWTO, available from
1707 <http://www.tldp.org/docs.html#howto>.
1709 This driver does not spin down disk drives (see the hdparm(8)
1710 manpage ("man 8 hdparm") for that), and it doesn't turn off
1711 VESA-compliant "green" monitors.
1713 This driver does not support the TI 4000M TravelMate and the ACER
1714 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1715 desktop machines also don't have compliant BIOSes, and this driver
1716 may cause those machines to panic during the boot phase.
1718 Generally, if you don't have a battery in your machine, there isn't
1719 much point in using this driver and you should say N. If you get
1720 random kernel OOPSes or reboots that don't seem to be related to
1721 anything, try disabling/enabling this option (or disabling/enabling
1724 Some other things you should try when experiencing seemingly random,
1727 1) make sure that you have enough swap space and that it is
1729 2) pass the "no-hlt" option to the kernel
1730 3) switch on floating point emulation in the kernel and pass
1731 the "no387" option to the kernel
1732 4) pass the "floppy=nodma" option to the kernel
1733 5) pass the "mem=4M" option to the kernel (thereby disabling
1734 all but the first 4 MB of RAM)
1735 6) make sure that the CPU is not over clocked.
1736 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1737 8) disable the cache from your BIOS settings
1738 9) install a fan for the video card or exchange video RAM
1739 10) install a better fan for the CPU
1740 11) exchange RAM chips
1741 12) exchange the motherboard.
1743 To compile this driver as a module, choose M here: the
1744 module will be called apm.
1748 config APM_IGNORE_USER_SUSPEND
1749 bool "Ignore USER SUSPEND"
1751 This option will ignore USER SUSPEND requests. On machines with a
1752 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1753 series notebooks, it is necessary to say Y because of a BIOS bug.
1755 config APM_DO_ENABLE
1756 bool "Enable PM at boot time"
1758 Enable APM features at boot time. From page 36 of the APM BIOS
1759 specification: "When disabled, the APM BIOS does not automatically
1760 power manage devices, enter the Standby State, enter the Suspend
1761 State, or take power saving steps in response to CPU Idle calls."
1762 This driver will make CPU Idle calls when Linux is idle (unless this
1763 feature is turned off -- see "Do CPU IDLE calls", below). This
1764 should always save battery power, but more complicated APM features
1765 will be dependent on your BIOS implementation. You may need to turn
1766 this option off if your computer hangs at boot time when using APM
1767 support, or if it beeps continuously instead of suspending. Turn
1768 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1769 T400CDT. This is off by default since most machines do fine without
1773 bool "Make CPU Idle calls when idle"
1775 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1776 On some machines, this can activate improved power savings, such as
1777 a slowed CPU clock rate, when the machine is idle. These idle calls
1778 are made after the idle loop has run for some length of time (e.g.,
1779 333 mS). On some machines, this will cause a hang at boot time or
1780 whenever the CPU becomes idle. (On machines with more than one CPU,
1781 this option does nothing.)
1783 config APM_DISPLAY_BLANK
1784 bool "Enable console blanking using APM"
1786 Enable console blanking using the APM. Some laptops can use this to
1787 turn off the LCD backlight when the screen blanker of the Linux
1788 virtual console blanks the screen. Note that this is only used by
1789 the virtual console screen blanker, and won't turn off the backlight
1790 when using the X Window system. This also doesn't have anything to
1791 do with your VESA-compliant power-saving monitor. Further, this
1792 option doesn't work for all laptops -- it might not turn off your
1793 backlight at all, or it might print a lot of errors to the console,
1794 especially if you are using gpm.
1796 config APM_ALLOW_INTS
1797 bool "Allow interrupts during APM BIOS calls"
1799 Normally we disable external interrupts while we are making calls to
1800 the APM BIOS as a measure to lessen the effects of a badly behaving
1801 BIOS implementation. The BIOS should reenable interrupts if it
1802 needs to. Unfortunately, some BIOSes do not -- especially those in
1803 many of the newer IBM Thinkpads. If you experience hangs when you
1804 suspend, try setting this to Y. Otherwise, say N.
1808 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1810 source "drivers/cpuidle/Kconfig"
1812 source "drivers/idle/Kconfig"
1817 menu "Bus options (PCI etc.)"
1822 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1824 Find out whether you have a PCI motherboard. PCI is the name of a
1825 bus system, i.e. the way the CPU talks to the other stuff inside
1826 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1827 VESA. If you have PCI, say Y, otherwise N.
1830 prompt "PCI access mode"
1831 depends on X86_32 && PCI
1834 On PCI systems, the BIOS can be used to detect the PCI devices and
1835 determine their configuration. However, some old PCI motherboards
1836 have BIOS bugs and may crash if this is done. Also, some embedded
1837 PCI-based systems don't have any BIOS at all. Linux can also try to
1838 detect the PCI hardware directly without using the BIOS.
1840 With this option, you can specify how Linux should detect the
1841 PCI devices. If you choose "BIOS", the BIOS will be used,
1842 if you choose "Direct", the BIOS won't be used, and if you
1843 choose "MMConfig", then PCI Express MMCONFIG will be used.
1844 If you choose "Any", the kernel will try MMCONFIG, then the
1845 direct access method and falls back to the BIOS if that doesn't
1846 work. If unsure, go with the default, which is "Any".
1851 config PCI_GOMMCONFIG
1868 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1870 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1873 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1877 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1881 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1888 bool "Support mmconfig PCI config space access"
1889 depends on X86_64 && PCI && ACPI
1892 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1893 depends on PCI_MSI && ACPI && EXPERIMENTAL
1895 DMA remapping (DMAR) devices support enables independent address
1896 translations for Direct Memory Access (DMA) from devices.
1897 These DMA remapping devices are reported via ACPI tables
1898 and include PCI device scope covered by these DMA
1901 config DMAR_DEFAULT_ON
1903 prompt "Enable DMA Remapping Devices by default"
1906 Selecting this option will enable a DMAR device at boot time if
1907 one is found. If this option is not selected, DMAR support can
1908 be enabled by passing intel_iommu=on to the kernel. It is
1909 recommended you say N here while the DMAR code remains
1912 config DMAR_BROKEN_GFX_WA
1914 prompt "Workaround broken graphics drivers (going away soon)"
1915 depends on DMAR && BROKEN
1917 Current Graphics drivers tend to use physical address
1918 for DMA and avoid using DMA APIs. Setting this config
1919 option permits the IOMMU driver to set a unity map for
1920 all the OS-visible memory. Hence the driver can continue
1921 to use physical addresses for DMA, at least until this
1922 option is removed in the 2.6.32 kernel.
1924 config DMAR_FLOPPY_WA
1928 Floppy disk drivers are known to bypass DMA API calls
1929 thereby failing to work when IOMMU is enabled. This
1930 workaround will setup a 1:1 mapping for the first
1931 16MiB to make floppy (an ISA device) work.
1934 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1935 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1937 Supports Interrupt remapping for IO-APIC and MSI devices.
1938 To use x2apic mode in the CPU's which support x2APIC enhancements or
1939 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1941 source "drivers/pci/pcie/Kconfig"
1943 source "drivers/pci/Kconfig"
1945 # x86_64 have no ISA slots, but do have ISA-style DMA.
1954 Find out whether you have ISA slots on your motherboard. ISA is the
1955 name of a bus system, i.e. the way the CPU talks to the other stuff
1956 inside your box. Other bus systems are PCI, EISA, MicroChannel
1957 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1958 newer boards don't support it. If you have ISA, say Y, otherwise N.
1964 The Extended Industry Standard Architecture (EISA) bus was
1965 developed as an open alternative to the IBM MicroChannel bus.
1967 The EISA bus provided some of the features of the IBM MicroChannel
1968 bus while maintaining backward compatibility with cards made for
1969 the older ISA bus. The EISA bus saw limited use between 1988 and
1970 1995 when it was made obsolete by the PCI bus.
1972 Say Y here if you are building a kernel for an EISA-based machine.
1976 source "drivers/eisa/Kconfig"
1981 MicroChannel Architecture is found in some IBM PS/2 machines and
1982 laptops. It is a bus system similar to PCI or ISA. See
1983 <file:Documentation/mca.txt> (and especially the web page given
1984 there) before attempting to build an MCA bus kernel.
1986 source "drivers/mca/Kconfig"
1989 tristate "NatSemi SCx200 support"
1991 This provides basic support for National Semiconductor's
1992 (now AMD's) Geode processors. The driver probes for the
1993 PCI-IDs of several on-chip devices, so its a good dependency
1994 for other scx200_* drivers.
1996 If compiled as a module, the driver is named scx200.
1998 config SCx200HR_TIMER
1999 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2000 depends on SCx200 && GENERIC_TIME
2003 This driver provides a clocksource built upon the on-chip
2004 27MHz high-resolution timer. Its also a workaround for
2005 NSC Geode SC-1100's buggy TSC, which loses time when the
2006 processor goes idle (as is done by the scheduler). The
2007 other workaround is idle=poll boot option.
2009 config GEODE_MFGPT_TIMER
2011 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2012 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2014 This driver provides a clock event source based on the MFGPT
2015 timer(s) in the CS5535 and CS5536 companion chip for the geode.
2016 MFGPTs have a better resolution and max interval than the
2017 generic PIT, and are suitable for use as high-res timers.
2020 bool "One Laptop Per Child support"
2023 Add support for detecting the unique features of the OLPC
2030 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2032 source "drivers/pcmcia/Kconfig"
2034 source "drivers/pci/hotplug/Kconfig"
2039 menu "Executable file formats / Emulations"
2041 source "fs/Kconfig.binfmt"
2043 config IA32_EMULATION
2044 bool "IA32 Emulation"
2046 select COMPAT_BINFMT_ELF
2048 Include code to run 32-bit programs under a 64-bit kernel. You should
2049 likely turn this on, unless you're 100% sure that you don't have any
2050 32-bit programs left.
2053 tristate "IA32 a.out support"
2054 depends on IA32_EMULATION
2056 Support old a.out binaries in the 32bit emulation.
2060 depends on IA32_EMULATION
2062 config COMPAT_FOR_U64_ALIGNMENT
2066 config SYSVIPC_COMPAT
2068 depends on COMPAT && SYSVIPC
2073 config HAVE_ATOMIC_IOMAP
2077 source "net/Kconfig"
2079 source "drivers/Kconfig"
2081 source "drivers/firmware/Kconfig"
2085 source "arch/x86/Kconfig.debug"
2087 source "security/Kconfig"
2089 source "crypto/Kconfig"
2091 source "arch/x86/kvm/Kconfig"
2093 source "lib/Kconfig"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blob