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>.
436 bool "SGI 320/540 (Visual Workstation)"
437 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
438 depends on X86_32_NON_STANDARD
440 The SGI Visual Workstation series is an IA32-based workstation
441 based on SGI systems chips with some legacy PC hardware attached.
443 Say Y here to create a kernel to run on the SGI 320 or 540.
445 A kernel compiled for the Visual Workstation will run on general
446 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
449 bool "Summit/EXA (IBM x440)"
450 depends on X86_32_NON_STANDARD
452 This option is needed for IBM systems that use the Summit/EXA chipset.
453 In particular, it is needed for the x440.
456 bool "Unisys ES7000 IA32 series"
457 depends on X86_32_NON_STANDARD && X86_BIGSMP
459 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
460 supposed to run on an IA32-based Unisys ES7000 system.
462 config SCHED_OMIT_FRAME_POINTER
464 prompt "Single-depth WCHAN output"
467 Calculate simpler /proc/<PID>/wchan values. If this option
468 is disabled then wchan values will recurse back to the
469 caller function. This provides more accurate wchan values,
470 at the expense of slightly more scheduling overhead.
472 If in doubt, say "Y".
474 menuconfig PARAVIRT_GUEST
475 bool "Paravirtualized guest support"
477 Say Y here to get to see options related to running Linux under
478 various hypervisors. This option alone does not add any kernel code.
480 If you say N, all options in this submenu will be skipped and disabled.
484 source "arch/x86/xen/Kconfig"
487 bool "VMI Guest support"
491 VMI provides a paravirtualized interface to the VMware ESX server
492 (it could be used by other hypervisors in theory too, but is not
493 at the moment), by linking the kernel to a GPL-ed ROM module
494 provided by the hypervisor.
497 bool "KVM paravirtualized clock"
499 select PARAVIRT_CLOCK
501 Turning on this option will allow you to run a paravirtualized clock
502 when running over the KVM hypervisor. Instead of relying on a PIT
503 (or probably other) emulation by the underlying device model, the host
504 provides the guest with timing infrastructure such as time of day, and
508 bool "KVM Guest support"
511 This option enables various optimizations for running under the KVM
514 source "arch/x86/lguest/Kconfig"
517 bool "Enable paravirtualization code"
519 This changes the kernel so it can modify itself when it is run
520 under a hypervisor, potentially improving performance significantly
521 over full virtualization. However, when run without a hypervisor
522 the kernel is theoretically slower and slightly larger.
524 config PARAVIRT_SPINLOCKS
525 bool "Paravirtualization layer for spinlocks"
526 depends on PARAVIRT && SMP && EXPERIMENTAL
528 Paravirtualized spinlocks allow a pvops backend to replace the
529 spinlock implementation with something virtualization-friendly
530 (for example, block the virtual CPU rather than spinning).
532 Unfortunately the downside is an up to 5% performance hit on
533 native kernels, with various workloads.
535 If you are unsure how to answer this question, answer N.
537 config PARAVIRT_CLOCK
543 config PARAVIRT_DEBUG
544 bool "paravirt-ops debugging"
545 depends on PARAVIRT && DEBUG_KERNEL
547 Enable to debug paravirt_ops internals. Specifically, BUG if
548 a paravirt_op is missing when it is called.
553 This option adds a kernel parameter 'memtest', which allows memtest
555 memtest=0, mean disabled; -- default
556 memtest=1, mean do 1 test pattern;
558 memtest=4, mean do 4 test patterns.
559 If you are unsure how to answer this question, answer N.
561 config X86_SUMMIT_NUMA
563 depends on X86_32 && NUMA && X86_32_NON_STANDARD
565 config X86_CYCLONE_TIMER
567 depends on X86_32_NON_STANDARD
569 source "arch/x86/Kconfig.cpu"
573 prompt "HPET Timer Support" if X86_32
575 Use the IA-PC HPET (High Precision Event Timer) to manage
576 time in preference to the PIT and RTC, if a HPET is
578 HPET is the next generation timer replacing legacy 8254s.
579 The HPET provides a stable time base on SMP
580 systems, unlike the TSC, but it is more expensive to access,
581 as it is off-chip. You can find the HPET spec at
582 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
584 You can safely choose Y here. However, HPET will only be
585 activated if the platform and the BIOS support this feature.
586 Otherwise the 8254 will be used for timing services.
588 Choose N to continue using the legacy 8254 timer.
590 config HPET_EMULATE_RTC
592 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
594 # Mark as embedded because too many people got it wrong.
595 # The code disables itself when not needed.
598 bool "Enable DMI scanning" if EMBEDDED
600 Enabled scanning of DMI to identify machine quirks. Say Y
601 here unless you have verified that your setup is not
602 affected by entries in the DMI blacklist. Required by PNP
606 bool "GART IOMMU support" if EMBEDDED
609 depends on X86_64 && PCI
611 Support for full DMA access of devices with 32bit memory access only
612 on systems with more than 3GB. This is usually needed for USB,
613 sound, many IDE/SATA chipsets and some other devices.
614 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
615 based hardware IOMMU and a software bounce buffer based IOMMU used
616 on Intel systems and as fallback.
617 The code is only active when needed (enough memory and limited
618 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
622 bool "IBM Calgary IOMMU support"
624 depends on X86_64 && PCI && EXPERIMENTAL
626 Support for hardware IOMMUs in IBM's xSeries x366 and x460
627 systems. Needed to run systems with more than 3GB of memory
628 properly with 32-bit PCI devices that do not support DAC
629 (Double Address Cycle). Calgary also supports bus level
630 isolation, where all DMAs pass through the IOMMU. This
631 prevents them from going anywhere except their intended
632 destination. This catches hard-to-find kernel bugs and
633 mis-behaving drivers and devices that do not use the DMA-API
634 properly to set up their DMA buffers. The IOMMU can be
635 turned off at boot time with the iommu=off parameter.
636 Normally the kernel will make the right choice by itself.
639 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
641 prompt "Should Calgary be enabled by default?"
642 depends on CALGARY_IOMMU
644 Should Calgary be enabled by default? if you choose 'y', Calgary
645 will be used (if it exists). If you choose 'n', Calgary will not be
646 used even if it exists. If you choose 'n' and would like to use
647 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
651 bool "AMD IOMMU support"
654 depends on X86_64 && PCI && ACPI
656 With this option you can enable support for AMD IOMMU hardware in
657 your system. An IOMMU is a hardware component which provides
658 remapping of DMA memory accesses from devices. With an AMD IOMMU you
659 can isolate the the DMA memory of different devices and protect the
660 system from misbehaving device drivers or hardware.
662 You can find out if your system has an AMD IOMMU if you look into
663 your BIOS for an option to enable it or if you have an IVRS ACPI
666 config AMD_IOMMU_STATS
667 bool "Export AMD IOMMU statistics to debugfs"
671 This option enables code in the AMD IOMMU driver to collect various
672 statistics about whats happening in the driver and exports that
673 information to userspace via debugfs.
676 # need this always selected by IOMMU for the VIA workaround
680 Support for software bounce buffers used on x86-64 systems
681 which don't have a hardware IOMMU (e.g. the current generation
682 of Intel's x86-64 CPUs). Using this PCI devices which can only
683 access 32-bits of memory can be used on systems with more than
684 3 GB of memory. If unsure, say Y.
687 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
690 def_bool (AMD_IOMMU || DMAR)
693 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
694 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
695 select CPUMASK_OFFSTACK
698 Configure maximum number of CPUS and NUMA Nodes for this architecture.
702 int "Maximum number of CPUs" if SMP && !MAXSMP
703 range 2 8 if SMP && X86_32 && !X86_BIGSMP
704 range 2 512 if SMP && !MAXSMP
706 default "4096" if MAXSMP
707 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
710 This allows you to specify the maximum number of CPUs which this
711 kernel will support. The maximum supported value is 512 and the
712 minimum value which makes sense is 2.
714 This is purely to save memory - each supported CPU adds
715 approximately eight kilobytes to the kernel image.
718 bool "SMT (Hyperthreading) scheduler support"
721 SMT scheduler support improves the CPU scheduler's decision making
722 when dealing with Intel Pentium 4 chips with HyperThreading at a
723 cost of slightly increased overhead in some places. If unsure say
728 prompt "Multi-core scheduler support"
731 Multi-core scheduler support improves the CPU scheduler's decision
732 making when dealing with multi-core CPU chips at a cost of slightly
733 increased overhead in some places. If unsure say N here.
735 source "kernel/Kconfig.preempt"
738 bool "Local APIC support on uniprocessors"
739 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
741 A local APIC (Advanced Programmable Interrupt Controller) is an
742 integrated interrupt controller in the CPU. If you have a single-CPU
743 system which has a processor with a local APIC, you can say Y here to
744 enable and use it. If you say Y here even though your machine doesn't
745 have a local APIC, then the kernel will still run with no slowdown at
746 all. The local APIC supports CPU-generated self-interrupts (timer,
747 performance counters), and the NMI watchdog which detects hard
751 bool "IO-APIC support on uniprocessors"
752 depends on X86_UP_APIC
754 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
755 SMP-capable replacement for PC-style interrupt controllers. Most
756 SMP systems and many recent uniprocessor systems have one.
758 If you have a single-CPU system with an IO-APIC, you can say Y here
759 to use it. If you say Y here even though your machine doesn't have
760 an IO-APIC, then the kernel will still run with no slowdown at all.
762 config X86_LOCAL_APIC
764 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
768 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
770 config X86_VISWS_APIC
772 depends on X86_32 && X86_VISWS
774 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
775 bool "Reroute for broken boot IRQs"
777 depends on X86_IO_APIC
779 This option enables a workaround that fixes a source of
780 spurious interrupts. This is recommended when threaded
781 interrupt handling is used on systems where the generation of
782 superfluous "boot interrupts" cannot be disabled.
784 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
785 entry in the chipset's IO-APIC is masked (as, e.g. the RT
786 kernel does during interrupt handling). On chipsets where this
787 boot IRQ generation cannot be disabled, this workaround keeps
788 the original IRQ line masked so that only the equivalent "boot
789 IRQ" is delivered to the CPUs. The workaround also tells the
790 kernel to set up the IRQ handler on the boot IRQ line. In this
791 way only one interrupt is delivered to the kernel. Otherwise
792 the spurious second interrupt may cause the kernel to bring
793 down (vital) interrupt lines.
795 Only affects "broken" chipsets. Interrupt sharing may be
796 increased on these systems.
799 bool "Machine Check / overheating reporting"
801 Machine Check support allows the processor to notify the
802 kernel if it detects a problem (e.g. overheating, data corruption).
803 The action the kernel takes depends on the severity of the problem,
804 ranging from warning messages to halting the machine.
808 prompt "Intel MCE features"
809 depends on X86_MCE && X86_LOCAL_APIC
811 Additional support for intel specific MCE features such as
816 prompt "AMD MCE features"
817 depends on X86_MCE && X86_LOCAL_APIC
819 Additional support for AMD specific MCE features such as
820 the DRAM Error Threshold.
822 config X86_ANCIENT_MCE
824 depends on X86_32 && X86_MCE
825 prompt "Support for old Pentium 5 / WinChip machine checks"
827 Include support for machine check handling on old Pentium 5 or WinChip
828 systems. These typically need to be enabled explicitely on the command
831 config X86_MCE_THRESHOLD
832 depends on X86_MCE_AMD || X86_MCE_INTEL
836 config X86_MCE_INJECT
838 tristate "Machine check injector support"
840 Provide support for injecting machine checks for testing purposes.
841 If you don't know what a machine check is and you don't do kernel
842 QA it is safe to say n.
844 config X86_THERMAL_VECTOR
846 depends on X86_MCE_INTEL
849 bool "Enable VM86 support" if EMBEDDED
853 This option is required by programs like DOSEMU to run 16-bit legacy
854 code on X86 processors. It also may be needed by software like
855 XFree86 to initialize some video cards via BIOS. Disabling this
856 option saves about 6k.
859 tristate "Toshiba Laptop support"
862 This adds a driver to safely access the System Management Mode of
863 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
864 not work on models with a Phoenix BIOS. The System Management Mode
865 is used to set the BIOS and power saving options on Toshiba portables.
867 For information on utilities to make use of this driver see the
868 Toshiba Linux utilities web site at:
869 <http://www.buzzard.org.uk/toshiba/>.
871 Say Y if you intend to run this kernel on a Toshiba portable.
875 tristate "Dell laptop support"
877 This adds a driver to safely access the System Management Mode
878 of the CPU on the Dell Inspiron 8000. The System Management Mode
879 is used to read cpu temperature and cooling fan status and to
880 control the fans on the I8K portables.
882 This driver has been tested only on the Inspiron 8000 but it may
883 also work with other Dell laptops. You can force loading on other
884 models by passing the parameter `force=1' to the module. Use at
887 For information on utilities to make use of this driver see the
888 I8K Linux utilities web site at:
889 <http://people.debian.org/~dz/i8k/>
891 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
894 config X86_REBOOTFIXUPS
895 bool "Enable X86 board specific fixups for reboot"
898 This enables chipset and/or board specific fixups to be done
899 in order to get reboot to work correctly. This is only needed on
900 some combinations of hardware and BIOS. The symptom, for which
901 this config is intended, is when reboot ends with a stalled/hung
904 Currently, the only fixup is for the Geode machines using
905 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
907 Say Y if you want to enable the fixup. Currently, it's safe to
908 enable this option even if you don't need it.
912 tristate "/dev/cpu/microcode - microcode support"
915 If you say Y here, you will be able to update the microcode on
916 certain Intel and AMD processors. The Intel support is for the
917 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
918 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
919 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
920 You will obviously need the actual microcode binary data itself
921 which is not shipped with the Linux kernel.
923 This option selects the general module only, you need to select
924 at least one vendor specific module as well.
926 To compile this driver as a module, choose M here: the
927 module will be called microcode.
929 config MICROCODE_INTEL
930 bool "Intel microcode patch loading support"
935 This options enables microcode patch loading support for Intel
938 For latest news and information on obtaining all the required
939 Intel ingredients for this driver, check:
940 <http://www.urbanmyth.org/microcode/>.
943 bool "AMD microcode patch loading support"
947 If you select this option, microcode patch loading support for AMD
948 processors will be enabled.
950 config MICROCODE_OLD_INTERFACE
955 tristate "/dev/cpu/*/msr - Model-specific register support"
957 This device gives privileged processes access to the x86
958 Model-Specific Registers (MSRs). It is a character device with
959 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
960 MSR accesses are directed to a specific CPU on multi-processor
964 tristate "/dev/cpu/*/cpuid - CPU information support"
966 This device gives processes access to the x86 CPUID instruction to
967 be executed on a specific processor. It is a character device
968 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
972 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
974 If you select this option, this will provide various x86 CPUs
975 information through debugfs.
978 prompt "High Memory Support"
979 default HIGHMEM4G if !X86_NUMAQ
980 default HIGHMEM64G if X86_NUMAQ
985 depends on !X86_NUMAQ
987 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
988 However, the address space of 32-bit x86 processors is only 4
989 Gigabytes large. That means that, if you have a large amount of
990 physical memory, not all of it can be "permanently mapped" by the
991 kernel. The physical memory that's not permanently mapped is called
994 If you are compiling a kernel which will never run on a machine with
995 more than 1 Gigabyte total physical RAM, answer "off" here (default
996 choice and suitable for most users). This will result in a "3GB/1GB"
997 split: 3GB are mapped so that each process sees a 3GB virtual memory
998 space and the remaining part of the 4GB virtual memory space is used
999 by the kernel to permanently map as much physical memory as
1002 If the machine has between 1 and 4 Gigabytes physical RAM, then
1005 If more than 4 Gigabytes is used then answer "64GB" here. This
1006 selection turns Intel PAE (Physical Address Extension) mode on.
1007 PAE implements 3-level paging on IA32 processors. PAE is fully
1008 supported by Linux, PAE mode is implemented on all recent Intel
1009 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1010 then the kernel will not boot on CPUs that don't support PAE!
1012 The actual amount of total physical memory will either be
1013 auto detected or can be forced by using a kernel command line option
1014 such as "mem=256M". (Try "man bootparam" or see the documentation of
1015 your boot loader (lilo or loadlin) about how to pass options to the
1016 kernel at boot time.)
1018 If unsure, say "off".
1022 depends on !X86_NUMAQ
1024 Select this if you have a 32-bit processor and between 1 and 4
1025 gigabytes of physical RAM.
1029 depends on !M386 && !M486
1032 Select this if you have a 32-bit processor and more than 4
1033 gigabytes of physical RAM.
1038 depends on EXPERIMENTAL
1039 prompt "Memory split" if EMBEDDED
1043 Select the desired split between kernel and user memory.
1045 If the address range available to the kernel is less than the
1046 physical memory installed, the remaining memory will be available
1047 as "high memory". Accessing high memory is a little more costly
1048 than low memory, as it needs to be mapped into the kernel first.
1049 Note that increasing the kernel address space limits the range
1050 available to user programs, making the address space there
1051 tighter. Selecting anything other than the default 3G/1G split
1052 will also likely make your kernel incompatible with binary-only
1055 If you are not absolutely sure what you are doing, leave this
1059 bool "3G/1G user/kernel split"
1060 config VMSPLIT_3G_OPT
1062 bool "3G/1G user/kernel split (for full 1G low memory)"
1064 bool "2G/2G user/kernel split"
1065 config VMSPLIT_2G_OPT
1067 bool "2G/2G user/kernel split (for full 2G low memory)"
1069 bool "1G/3G user/kernel split"
1074 default 0xB0000000 if VMSPLIT_3G_OPT
1075 default 0x80000000 if VMSPLIT_2G
1076 default 0x78000000 if VMSPLIT_2G_OPT
1077 default 0x40000000 if VMSPLIT_1G
1083 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1086 bool "PAE (Physical Address Extension) Support"
1087 depends on X86_32 && !HIGHMEM4G
1089 PAE is required for NX support, and furthermore enables
1090 larger swapspace support for non-overcommit purposes. It
1091 has the cost of more pagetable lookup overhead, and also
1092 consumes more pagetable space per process.
1094 config ARCH_PHYS_ADDR_T_64BIT
1095 def_bool X86_64 || X86_PAE
1097 config DIRECT_GBPAGES
1098 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1102 Allow the kernel linear mapping to use 1GB pages on CPUs that
1103 support it. This can improve the kernel's performance a tiny bit by
1104 reducing TLB pressure. If in doubt, say "Y".
1106 # Common NUMA Features
1108 bool "Numa Memory Allocation and Scheduler Support"
1110 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1111 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1113 Enable NUMA (Non Uniform Memory Access) support.
1115 The kernel will try to allocate memory used by a CPU on the
1116 local memory controller of the CPU and add some more
1117 NUMA awareness to the kernel.
1119 For 64-bit this is recommended if the system is Intel Core i7
1120 (or later), AMD Opteron, or EM64T NUMA.
1122 For 32-bit this is only needed on (rare) 32-bit-only platforms
1123 that support NUMA topologies, such as NUMAQ / Summit, or if you
1124 boot a 32-bit kernel on a 64-bit NUMA platform.
1126 Otherwise, you should say N.
1128 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1129 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1133 prompt "Old style AMD Opteron NUMA detection"
1134 depends on X86_64 && NUMA && PCI
1136 Enable K8 NUMA node topology detection. You should say Y here if
1137 you have a multi processor AMD K8 system. This uses an old
1138 method to read the NUMA configuration directly from the builtin
1139 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1140 instead, which also takes priority if both are compiled in.
1142 config X86_64_ACPI_NUMA
1144 prompt "ACPI NUMA detection"
1145 depends on X86_64 && NUMA && ACPI && PCI
1148 Enable ACPI SRAT based node topology detection.
1150 # Some NUMA nodes have memory ranges that span
1151 # other nodes. Even though a pfn is valid and
1152 # between a node's start and end pfns, it may not
1153 # reside on that node. See memmap_init_zone()
1155 config NODES_SPAN_OTHER_NODES
1157 depends on X86_64_ACPI_NUMA
1160 bool "NUMA emulation"
1161 depends on X86_64 && NUMA
1163 Enable NUMA emulation. A flat machine will be split
1164 into virtual nodes when booted with "numa=fake=N", where N is the
1165 number of nodes. This is only useful for debugging.
1168 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1170 default "9" if MAXSMP
1171 default "6" if X86_64
1172 default "4" if X86_NUMAQ
1174 depends on NEED_MULTIPLE_NODES
1176 Specify the maximum number of NUMA Nodes available on the target
1177 system. Increases memory reserved to accommodate various tables.
1179 config HAVE_ARCH_BOOTMEM
1181 depends on X86_32 && NUMA
1183 config ARCH_HAVE_MEMORY_PRESENT
1185 depends on X86_32 && DISCONTIGMEM
1187 config NEED_NODE_MEMMAP_SIZE
1189 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1191 config HAVE_ARCH_ALLOC_REMAP
1193 depends on X86_32 && NUMA
1195 config ARCH_FLATMEM_ENABLE
1197 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1199 config ARCH_DISCONTIGMEM_ENABLE
1201 depends on NUMA && X86_32
1203 config ARCH_DISCONTIGMEM_DEFAULT
1205 depends on NUMA && X86_32
1207 config ARCH_SPARSEMEM_DEFAULT
1211 config ARCH_SPARSEMEM_ENABLE
1213 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1214 select SPARSEMEM_STATIC if X86_32
1215 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1217 config ARCH_SELECT_MEMORY_MODEL
1219 depends on ARCH_SPARSEMEM_ENABLE
1221 config ARCH_MEMORY_PROBE
1223 depends on MEMORY_HOTPLUG
1228 bool "Allocate 3rd-level pagetables from highmem"
1229 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1231 The VM uses one page table entry for each page of physical memory.
1232 For systems with a lot of RAM, this can be wasteful of precious
1233 low memory. Setting this option will put user-space page table
1234 entries in high memory.
1236 config X86_CHECK_BIOS_CORRUPTION
1237 bool "Check for low memory corruption"
1239 Periodically check for memory corruption in low memory, which
1240 is suspected to be caused by BIOS. Even when enabled in the
1241 configuration, it is disabled at runtime. Enable it by
1242 setting "memory_corruption_check=1" on the kernel command
1243 line. By default it scans the low 64k of memory every 60
1244 seconds; see the memory_corruption_check_size and
1245 memory_corruption_check_period parameters in
1246 Documentation/kernel-parameters.txt to adjust this.
1248 When enabled with the default parameters, this option has
1249 almost no overhead, as it reserves a relatively small amount
1250 of memory and scans it infrequently. It both detects corruption
1251 and prevents it from affecting the running system.
1253 It is, however, intended as a diagnostic tool; if repeatable
1254 BIOS-originated corruption always affects the same memory,
1255 you can use memmap= to prevent the kernel from using that
1258 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1259 bool "Set the default setting of memory_corruption_check"
1260 depends on X86_CHECK_BIOS_CORRUPTION
1263 Set whether the default state of memory_corruption_check is
1266 config X86_RESERVE_LOW_64K
1267 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1270 Reserve the first 64K of physical RAM on BIOSes that are known
1271 to potentially corrupt that memory range. A numbers of BIOSes are
1272 known to utilize this area during suspend/resume, so it must not
1273 be used by the kernel.
1275 Set this to N if you are absolutely sure that you trust the BIOS
1276 to get all its memory reservations and usages right.
1278 If you have doubts about the BIOS (e.g. suspend/resume does not
1279 work or there's kernel crashes after certain hardware hotplug
1280 events) and it's not AMI or Phoenix, then you might want to enable
1281 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1282 corruption patterns.
1286 config MATH_EMULATION
1288 prompt "Math emulation" if X86_32
1290 Linux can emulate a math coprocessor (used for floating point
1291 operations) if you don't have one. 486DX and Pentium processors have
1292 a math coprocessor built in, 486SX and 386 do not, unless you added
1293 a 487DX or 387, respectively. (The messages during boot time can
1294 give you some hints here ["man dmesg"].) Everyone needs either a
1295 coprocessor or this emulation.
1297 If you don't have a math coprocessor, you need to say Y here; if you
1298 say Y here even though you have a coprocessor, the coprocessor will
1299 be used nevertheless. (This behavior can be changed with the kernel
1300 command line option "no387", which comes handy if your coprocessor
1301 is broken. Try "man bootparam" or see the documentation of your boot
1302 loader (lilo or loadlin) about how to pass options to the kernel at
1303 boot time.) This means that it is a good idea to say Y here if you
1304 intend to use this kernel on different machines.
1306 More information about the internals of the Linux math coprocessor
1307 emulation can be found in <file:arch/x86/math-emu/README>.
1309 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1310 kernel, it won't hurt.
1313 bool "MTRR (Memory Type Range Register) support"
1315 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1316 the Memory Type Range Registers (MTRRs) may be used to control
1317 processor access to memory ranges. This is most useful if you have
1318 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1319 allows bus write transfers to be combined into a larger transfer
1320 before bursting over the PCI/AGP bus. This can increase performance
1321 of image write operations 2.5 times or more. Saying Y here creates a
1322 /proc/mtrr file which may be used to manipulate your processor's
1323 MTRRs. Typically the X server should use this.
1325 This code has a reasonably generic interface so that similar
1326 control registers on other processors can be easily supported
1329 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1330 Registers (ARRs) which provide a similar functionality to MTRRs. For
1331 these, the ARRs are used to emulate the MTRRs.
1332 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1333 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1334 write-combining. All of these processors are supported by this code
1335 and it makes sense to say Y here if you have one of them.
1337 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1338 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1339 can lead to all sorts of problems, so it's good to say Y here.
1341 You can safely say Y even if your machine doesn't have MTRRs, you'll
1342 just add about 9 KB to your kernel.
1344 See <file:Documentation/x86/mtrr.txt> for more information.
1346 config MTRR_SANITIZER
1348 prompt "MTRR cleanup support"
1351 Convert MTRR layout from continuous to discrete, so X drivers can
1352 add writeback entries.
1354 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1355 The largest mtrr entry size for a continuous block can be set with
1360 config MTRR_SANITIZER_ENABLE_DEFAULT
1361 int "MTRR cleanup enable value (0-1)"
1364 depends on MTRR_SANITIZER
1366 Enable mtrr cleanup default value
1368 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1369 int "MTRR cleanup spare reg num (0-7)"
1372 depends on MTRR_SANITIZER
1374 mtrr cleanup spare entries default, it can be changed via
1375 mtrr_spare_reg_nr=N on the kernel command line.
1379 prompt "x86 PAT support"
1382 Use PAT attributes to setup page level cache control.
1384 PATs are the modern equivalents of MTRRs and are much more
1385 flexible than MTRRs.
1387 Say N here if you see bootup problems (boot crash, boot hang,
1388 spontaneous reboots) or a non-working video driver.
1392 config ARCH_USES_PG_UNCACHED
1397 bool "EFI runtime service support"
1400 This enables the kernel to use EFI runtime services that are
1401 available (such as the EFI variable services).
1403 This option is only useful on systems that have EFI firmware.
1404 In addition, you should use the latest ELILO loader available
1405 at <http://elilo.sourceforge.net> in order to take advantage
1406 of EFI runtime services. However, even with this option, the
1407 resultant kernel should continue to boot on existing non-EFI
1412 prompt "Enable seccomp to safely compute untrusted bytecode"
1414 This kernel feature is useful for number crunching applications
1415 that may need to compute untrusted bytecode during their
1416 execution. By using pipes or other transports made available to
1417 the process as file descriptors supporting the read/write
1418 syscalls, it's possible to isolate those applications in
1419 their own address space using seccomp. Once seccomp is
1420 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1421 and the task is only allowed to execute a few safe syscalls
1422 defined by each seccomp mode.
1424 If unsure, say Y. Only embedded should say N here.
1426 config CC_STACKPROTECTOR_ALL
1429 config CC_STACKPROTECTOR
1430 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1431 select CC_STACKPROTECTOR_ALL
1433 This option turns on the -fstack-protector GCC feature. This
1434 feature puts, at the beginning of functions, a canary value on
1435 the stack just before the return address, and validates
1436 the value just before actually returning. Stack based buffer
1437 overflows (that need to overwrite this return address) now also
1438 overwrite the canary, which gets detected and the attack is then
1439 neutralized via a kernel panic.
1441 This feature requires gcc version 4.2 or above, or a distribution
1442 gcc with the feature backported. Older versions are automatically
1443 detected and for those versions, this configuration option is
1444 ignored. (and a warning is printed during bootup)
1446 source kernel/Kconfig.hz
1449 bool "kexec system call"
1451 kexec is a system call that implements the ability to shutdown your
1452 current kernel, and to start another kernel. It is like a reboot
1453 but it is independent of the system firmware. And like a reboot
1454 you can start any kernel with it, not just Linux.
1456 The name comes from the similarity to the exec system call.
1458 It is an ongoing process to be certain the hardware in a machine
1459 is properly shutdown, so do not be surprised if this code does not
1460 initially work for you. It may help to enable device hotplugging
1461 support. As of this writing the exact hardware interface is
1462 strongly in flux, so no good recommendation can be made.
1465 bool "kernel crash dumps"
1466 depends on X86_64 || (X86_32 && HIGHMEM)
1468 Generate crash dump after being started by kexec.
1469 This should be normally only set in special crash dump kernels
1470 which are loaded in the main kernel with kexec-tools into
1471 a specially reserved region and then later executed after
1472 a crash by kdump/kexec. The crash dump kernel must be compiled
1473 to a memory address not used by the main kernel or BIOS using
1474 PHYSICAL_START, or it must be built as a relocatable image
1475 (CONFIG_RELOCATABLE=y).
1476 For more details see Documentation/kdump/kdump.txt
1479 bool "kexec jump (EXPERIMENTAL)"
1480 depends on EXPERIMENTAL
1481 depends on KEXEC && HIBERNATION
1483 Jump between original kernel and kexeced kernel and invoke
1484 code in physical address mode via KEXEC
1486 config PHYSICAL_START
1487 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1490 This gives the physical address where the kernel is loaded.
1492 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1493 bzImage will decompress itself to above physical address and
1494 run from there. Otherwise, bzImage will run from the address where
1495 it has been loaded by the boot loader and will ignore above physical
1498 In normal kdump cases one does not have to set/change this option
1499 as now bzImage can be compiled as a completely relocatable image
1500 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1501 address. This option is mainly useful for the folks who don't want
1502 to use a bzImage for capturing the crash dump and want to use a
1503 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1504 to be specifically compiled to run from a specific memory area
1505 (normally a reserved region) and this option comes handy.
1507 So if you are using bzImage for capturing the crash dump,
1508 leave the value here unchanged to 0x1000000 and set
1509 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1510 for capturing the crash dump change this value to start of
1511 the reserved region. In other words, it can be set based on
1512 the "X" value as specified in the "crashkernel=YM@XM"
1513 command line boot parameter passed to the panic-ed
1514 kernel. Please take a look at Documentation/kdump/kdump.txt
1515 for more details about crash dumps.
1517 Usage of bzImage for capturing the crash dump is recommended as
1518 one does not have to build two kernels. Same kernel can be used
1519 as production kernel and capture kernel. Above option should have
1520 gone away after relocatable bzImage support is introduced. But it
1521 is present because there are users out there who continue to use
1522 vmlinux for dump capture. This option should go away down the
1525 Don't change this unless you know what you are doing.
1528 bool "Build a relocatable kernel"
1531 This builds a kernel image that retains relocation information
1532 so it can be loaded someplace besides the default 1MB.
1533 The relocations tend to make the kernel binary about 10% larger,
1534 but are discarded at runtime.
1536 One use is for the kexec on panic case where the recovery kernel
1537 must live at a different physical address than the primary
1540 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1541 it has been loaded at and the compile time physical address
1542 (CONFIG_PHYSICAL_START) is ignored.
1544 # Relocation on x86-32 needs some additional build support
1545 config X86_NEED_RELOCS
1547 depends on X86_32 && RELOCATABLE
1549 config PHYSICAL_ALIGN
1551 prompt "Alignment value to which kernel should be aligned" if X86_32
1553 range 0x2000 0x1000000
1555 This value puts the alignment restrictions on physical address
1556 where kernel is loaded and run from. Kernel is compiled for an
1557 address which meets above alignment restriction.
1559 If bootloader loads the kernel at a non-aligned address and
1560 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1561 address aligned to above value and run from there.
1563 If bootloader loads the kernel at a non-aligned address and
1564 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1565 load address and decompress itself to the address it has been
1566 compiled for and run from there. The address for which kernel is
1567 compiled already meets above alignment restrictions. Hence the
1568 end result is that kernel runs from a physical address meeting
1569 above alignment restrictions.
1571 Don't change this unless you know what you are doing.
1574 bool "Support for hot-pluggable CPUs"
1575 depends on SMP && HOTPLUG
1577 Say Y here to allow turning CPUs off and on. CPUs can be
1578 controlled through /sys/devices/system/cpu.
1579 ( Note: power management support will enable this option
1580 automatically on SMP systems. )
1581 Say N if you want to disable CPU hotplug.
1585 prompt "Compat VDSO support"
1586 depends on X86_32 || IA32_EMULATION
1588 Map the 32-bit VDSO to the predictable old-style address too.
1590 Say N here if you are running a sufficiently recent glibc
1591 version (2.3.3 or later), to remove the high-mapped
1592 VDSO mapping and to exclusively use the randomized VDSO.
1597 bool "Built-in kernel command line"
1600 Allow for specifying boot arguments to the kernel at
1601 build time. On some systems (e.g. embedded ones), it is
1602 necessary or convenient to provide some or all of the
1603 kernel boot arguments with the kernel itself (that is,
1604 to not rely on the boot loader to provide them.)
1606 To compile command line arguments into the kernel,
1607 set this option to 'Y', then fill in the
1608 the boot arguments in CONFIG_CMDLINE.
1610 Systems with fully functional boot loaders (i.e. non-embedded)
1611 should leave this option set to 'N'.
1614 string "Built-in kernel command string"
1615 depends on CMDLINE_BOOL
1618 Enter arguments here that should be compiled into the kernel
1619 image and used at boot time. If the boot loader provides a
1620 command line at boot time, it is appended to this string to
1621 form the full kernel command line, when the system boots.
1623 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1624 change this behavior.
1626 In most cases, the command line (whether built-in or provided
1627 by the boot loader) should specify the device for the root
1630 config CMDLINE_OVERRIDE
1631 bool "Built-in command line overrides boot loader arguments"
1633 depends on CMDLINE_BOOL
1635 Set this option to 'Y' to have the kernel ignore the boot loader
1636 command line, and use ONLY the built-in command line.
1638 This is used to work around broken boot loaders. This should
1639 be set to 'N' under normal conditions.
1643 config ARCH_ENABLE_MEMORY_HOTPLUG
1645 depends on X86_64 || (X86_32 && HIGHMEM)
1647 config ARCH_ENABLE_MEMORY_HOTREMOVE
1649 depends on MEMORY_HOTPLUG
1651 config HAVE_ARCH_EARLY_PFN_TO_NID
1655 menu "Power management and ACPI options"
1657 config ARCH_HIBERNATION_HEADER
1659 depends on X86_64 && HIBERNATION
1661 source "kernel/power/Kconfig"
1663 source "drivers/acpi/Kconfig"
1668 depends on APM || APM_MODULE
1671 tristate "APM (Advanced Power Management) BIOS support"
1672 depends on X86_32 && PM_SLEEP
1674 APM is a BIOS specification for saving power using several different
1675 techniques. This is mostly useful for battery powered laptops with
1676 APM compliant BIOSes. If you say Y here, the system time will be
1677 reset after a RESUME operation, the /proc/apm device will provide
1678 battery status information, and user-space programs will receive
1679 notification of APM "events" (e.g. battery status change).
1681 If you select "Y" here, you can disable actual use of the APM
1682 BIOS by passing the "apm=off" option to the kernel at boot time.
1684 Note that the APM support is almost completely disabled for
1685 machines with more than one CPU.
1687 In order to use APM, you will need supporting software. For location
1688 and more information, read <file:Documentation/power/pm.txt> and the
1689 Battery Powered Linux mini-HOWTO, available from
1690 <http://www.tldp.org/docs.html#howto>.
1692 This driver does not spin down disk drives (see the hdparm(8)
1693 manpage ("man 8 hdparm") for that), and it doesn't turn off
1694 VESA-compliant "green" monitors.
1696 This driver does not support the TI 4000M TravelMate and the ACER
1697 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1698 desktop machines also don't have compliant BIOSes, and this driver
1699 may cause those machines to panic during the boot phase.
1701 Generally, if you don't have a battery in your machine, there isn't
1702 much point in using this driver and you should say N. If you get
1703 random kernel OOPSes or reboots that don't seem to be related to
1704 anything, try disabling/enabling this option (or disabling/enabling
1707 Some other things you should try when experiencing seemingly random,
1710 1) make sure that you have enough swap space and that it is
1712 2) pass the "no-hlt" option to the kernel
1713 3) switch on floating point emulation in the kernel and pass
1714 the "no387" option to the kernel
1715 4) pass the "floppy=nodma" option to the kernel
1716 5) pass the "mem=4M" option to the kernel (thereby disabling
1717 all but the first 4 MB of RAM)
1718 6) make sure that the CPU is not over clocked.
1719 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1720 8) disable the cache from your BIOS settings
1721 9) install a fan for the video card or exchange video RAM
1722 10) install a better fan for the CPU
1723 11) exchange RAM chips
1724 12) exchange the motherboard.
1726 To compile this driver as a module, choose M here: the
1727 module will be called apm.
1731 config APM_IGNORE_USER_SUSPEND
1732 bool "Ignore USER SUSPEND"
1734 This option will ignore USER SUSPEND requests. On machines with a
1735 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1736 series notebooks, it is necessary to say Y because of a BIOS bug.
1738 config APM_DO_ENABLE
1739 bool "Enable PM at boot time"
1741 Enable APM features at boot time. From page 36 of the APM BIOS
1742 specification: "When disabled, the APM BIOS does not automatically
1743 power manage devices, enter the Standby State, enter the Suspend
1744 State, or take power saving steps in response to CPU Idle calls."
1745 This driver will make CPU Idle calls when Linux is idle (unless this
1746 feature is turned off -- see "Do CPU IDLE calls", below). This
1747 should always save battery power, but more complicated APM features
1748 will be dependent on your BIOS implementation. You may need to turn
1749 this option off if your computer hangs at boot time when using APM
1750 support, or if it beeps continuously instead of suspending. Turn
1751 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1752 T400CDT. This is off by default since most machines do fine without
1756 bool "Make CPU Idle calls when idle"
1758 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1759 On some machines, this can activate improved power savings, such as
1760 a slowed CPU clock rate, when the machine is idle. These idle calls
1761 are made after the idle loop has run for some length of time (e.g.,
1762 333 mS). On some machines, this will cause a hang at boot time or
1763 whenever the CPU becomes idle. (On machines with more than one CPU,
1764 this option does nothing.)
1766 config APM_DISPLAY_BLANK
1767 bool "Enable console blanking using APM"
1769 Enable console blanking using the APM. Some laptops can use this to
1770 turn off the LCD backlight when the screen blanker of the Linux
1771 virtual console blanks the screen. Note that this is only used by
1772 the virtual console screen blanker, and won't turn off the backlight
1773 when using the X Window system. This also doesn't have anything to
1774 do with your VESA-compliant power-saving monitor. Further, this
1775 option doesn't work for all laptops -- it might not turn off your
1776 backlight at all, or it might print a lot of errors to the console,
1777 especially if you are using gpm.
1779 config APM_ALLOW_INTS
1780 bool "Allow interrupts during APM BIOS calls"
1782 Normally we disable external interrupts while we are making calls to
1783 the APM BIOS as a measure to lessen the effects of a badly behaving
1784 BIOS implementation. The BIOS should reenable interrupts if it
1785 needs to. Unfortunately, some BIOSes do not -- especially those in
1786 many of the newer IBM Thinkpads. If you experience hangs when you
1787 suspend, try setting this to Y. Otherwise, say N.
1791 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1793 source "drivers/cpuidle/Kconfig"
1795 source "drivers/idle/Kconfig"
1800 menu "Bus options (PCI etc.)"
1805 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1807 Find out whether you have a PCI motherboard. PCI is the name of a
1808 bus system, i.e. the way the CPU talks to the other stuff inside
1809 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1810 VESA. If you have PCI, say Y, otherwise N.
1813 prompt "PCI access mode"
1814 depends on X86_32 && PCI
1817 On PCI systems, the BIOS can be used to detect the PCI devices and
1818 determine their configuration. However, some old PCI motherboards
1819 have BIOS bugs and may crash if this is done. Also, some embedded
1820 PCI-based systems don't have any BIOS at all. Linux can also try to
1821 detect the PCI hardware directly without using the BIOS.
1823 With this option, you can specify how Linux should detect the
1824 PCI devices. If you choose "BIOS", the BIOS will be used,
1825 if you choose "Direct", the BIOS won't be used, and if you
1826 choose "MMConfig", then PCI Express MMCONFIG will be used.
1827 If you choose "Any", the kernel will try MMCONFIG, then the
1828 direct access method and falls back to the BIOS if that doesn't
1829 work. If unsure, go with the default, which is "Any".
1834 config PCI_GOMMCONFIG
1851 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1853 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1856 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1860 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1864 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1871 bool "Support mmconfig PCI config space access"
1872 depends on X86_64 && PCI && ACPI
1875 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1876 depends on PCI_MSI && ACPI && EXPERIMENTAL
1878 DMA remapping (DMAR) devices support enables independent address
1879 translations for Direct Memory Access (DMA) from devices.
1880 These DMA remapping devices are reported via ACPI tables
1881 and include PCI device scope covered by these DMA
1884 config DMAR_DEFAULT_ON
1886 prompt "Enable DMA Remapping Devices by default"
1889 Selecting this option will enable a DMAR device at boot time if
1890 one is found. If this option is not selected, DMAR support can
1891 be enabled by passing intel_iommu=on to the kernel. It is
1892 recommended you say N here while the DMAR code remains
1895 config DMAR_BROKEN_GFX_WA
1897 prompt "Workaround broken graphics drivers (going away soon)"
1900 Current Graphics drivers tend to use physical address
1901 for DMA and avoid using DMA APIs. Setting this config
1902 option permits the IOMMU driver to set a unity map for
1903 all the OS-visible memory. Hence the driver can continue
1904 to use physical addresses for DMA, at least until this
1905 option is removed in the 2.6.32 kernel.
1907 config DMAR_FLOPPY_WA
1911 Floppy disk drivers are known to bypass DMA API calls
1912 thereby failing to work when IOMMU is enabled. This
1913 workaround will setup a 1:1 mapping for the first
1914 16MiB to make floppy (an ISA device) work.
1917 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1918 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1920 Supports Interrupt remapping for IO-APIC and MSI devices.
1921 To use x2apic mode in the CPU's which support x2APIC enhancements or
1922 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1924 source "drivers/pci/pcie/Kconfig"
1926 source "drivers/pci/Kconfig"
1928 # x86_64 have no ISA slots, but do have ISA-style DMA.
1937 Find out whether you have ISA slots on your motherboard. ISA is the
1938 name of a bus system, i.e. the way the CPU talks to the other stuff
1939 inside your box. Other bus systems are PCI, EISA, MicroChannel
1940 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1941 newer boards don't support it. If you have ISA, say Y, otherwise N.
1947 The Extended Industry Standard Architecture (EISA) bus was
1948 developed as an open alternative to the IBM MicroChannel bus.
1950 The EISA bus provided some of the features of the IBM MicroChannel
1951 bus while maintaining backward compatibility with cards made for
1952 the older ISA bus. The EISA bus saw limited use between 1988 and
1953 1995 when it was made obsolete by the PCI bus.
1955 Say Y here if you are building a kernel for an EISA-based machine.
1959 source "drivers/eisa/Kconfig"
1964 MicroChannel Architecture is found in some IBM PS/2 machines and
1965 laptops. It is a bus system similar to PCI or ISA. See
1966 <file:Documentation/mca.txt> (and especially the web page given
1967 there) before attempting to build an MCA bus kernel.
1969 source "drivers/mca/Kconfig"
1972 tristate "NatSemi SCx200 support"
1974 This provides basic support for National Semiconductor's
1975 (now AMD's) Geode processors. The driver probes for the
1976 PCI-IDs of several on-chip devices, so its a good dependency
1977 for other scx200_* drivers.
1979 If compiled as a module, the driver is named scx200.
1981 config SCx200HR_TIMER
1982 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1983 depends on SCx200 && GENERIC_TIME
1986 This driver provides a clocksource built upon the on-chip
1987 27MHz high-resolution timer. Its also a workaround for
1988 NSC Geode SC-1100's buggy TSC, which loses time when the
1989 processor goes idle (as is done by the scheduler). The
1990 other workaround is idle=poll boot option.
1992 config GEODE_MFGPT_TIMER
1994 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1995 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1997 This driver provides a clock event source based on the MFGPT
1998 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1999 MFGPTs have a better resolution and max interval than the
2000 generic PIT, and are suitable for use as high-res timers.
2003 bool "One Laptop Per Child support"
2006 Add support for detecting the unique features of the OLPC
2013 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2015 source "drivers/pcmcia/Kconfig"
2017 source "drivers/pci/hotplug/Kconfig"
2022 menu "Executable file formats / Emulations"
2024 source "fs/Kconfig.binfmt"
2026 config IA32_EMULATION
2027 bool "IA32 Emulation"
2029 select COMPAT_BINFMT_ELF
2031 Include code to run 32-bit programs under a 64-bit kernel. You should
2032 likely turn this on, unless you're 100% sure that you don't have any
2033 32-bit programs left.
2036 tristate "IA32 a.out support"
2037 depends on IA32_EMULATION
2039 Support old a.out binaries in the 32bit emulation.
2043 depends on IA32_EMULATION
2045 config COMPAT_FOR_U64_ALIGNMENT
2049 config SYSVIPC_COMPAT
2051 depends on COMPAT && SYSVIPC
2056 config HAVE_ATOMIC_IOMAP
2060 source "net/Kconfig"
2062 source "drivers/Kconfig"
2064 source "drivers/firmware/Kconfig"
2068 source "arch/x86/Kconfig.debug"
2070 source "security/Kconfig"
2072 source "crypto/Kconfig"
2074 source "arch/x86/kvm/Kconfig"
2076 source "lib/Kconfig"
projects / deliverable / linux.git / blob