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
22 select HAVE_UNSTABLE_SCHED_CLOCK
25 select HAVE_IOREMAP_PROT
27 select ARCH_WANT_OPTIONAL_GPIOLIB
28 select HAVE_KRETPROBES
29 select HAVE_FTRACE_MCOUNT_RECORD
30 select HAVE_DYNAMIC_FTRACE
31 select HAVE_FUNCTION_TRACER
32 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
33 select HAVE_ARCH_KGDB if !X86_VOYAGER
34 select HAVE_ARCH_TRACEHOOK
35 select HAVE_GENERIC_DMA_COHERENT if X86_32
36 select HAVE_EFFICIENT_UNALIGNED_ACCESS
40 default "arch/x86/configs/i386_defconfig" if X86_32
41 default "arch/x86/configs/x86_64_defconfig" if X86_64
46 config GENERIC_CMOS_UPDATE
49 config CLOCKSOURCE_WATCHDOG
52 config GENERIC_CLOCKEVENTS
55 config GENERIC_CLOCKEVENTS_BROADCAST
57 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
59 config LOCKDEP_SUPPORT
62 config STACKTRACE_SUPPORT
65 config HAVE_LATENCYTOP_SUPPORT
68 config FAST_CMPXCHG_LOCAL
81 config GENERIC_ISA_DMA
91 config GENERIC_HWEIGHT
97 config ARCH_MAY_HAVE_PC_FDC
100 config RWSEM_GENERIC_SPINLOCK
103 config RWSEM_XCHGADD_ALGORITHM
106 config ARCH_HAS_CPU_IDLE_WAIT
109 config GENERIC_CALIBRATE_DELAY
112 config GENERIC_TIME_VSYSCALL
116 config ARCH_HAS_CPU_RELAX
119 config ARCH_HAS_DEFAULT_IDLE
122 config ARCH_HAS_CACHE_LINE_SIZE
125 config HAVE_SETUP_PER_CPU_AREA
126 def_bool X86_64_SMP || (X86_SMP && !X86_VOYAGER)
128 config HAVE_CPUMASK_OF_CPU_MAP
131 config ARCH_HIBERNATION_POSSIBLE
133 depends on !SMP || !X86_VOYAGER
135 config ARCH_SUSPEND_POSSIBLE
137 depends on !X86_VOYAGER
143 config ARCH_POPULATES_NODE_MAP
150 config ARCH_SUPPORTS_OPTIMIZED_INLINING
153 # Use the generic interrupt handling code in kernel/irq/:
154 config GENERIC_HARDIRQS
158 config GENERIC_IRQ_PROBE
162 config GENERIC_PENDING_IRQ
164 depends on GENERIC_HARDIRQS && SMP
169 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
172 config USE_GENERIC_SMP_HELPERS
178 depends on X86_32 && SMP
182 depends on X86_64 && SMP
187 depends on (X86_32 && !X86_VOYAGER) || X86_64
190 config X86_BIOS_REBOOT
192 depends on !X86_VOYAGER
195 config X86_TRAMPOLINE
197 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
202 source "init/Kconfig"
203 source "kernel/Kconfig.freezer"
205 menu "Processor type and features"
207 source "kernel/time/Kconfig"
210 bool "Symmetric multi-processing support"
212 This enables support for systems with more than one CPU. If you have
213 a system with only one CPU, like most personal computers, say N. If
214 you have a system with more than one CPU, say Y.
216 If you say N here, the kernel will run on single and multiprocessor
217 machines, but will use only one CPU of a multiprocessor machine. If
218 you say Y here, the kernel will run on many, but not all,
219 singleprocessor machines. On a singleprocessor machine, the kernel
220 will run faster if you say N here.
222 Note that if you say Y here and choose architecture "586" or
223 "Pentium" under "Processor family", the kernel will not work on 486
224 architectures. Similarly, multiprocessor kernels for the "PPro"
225 architecture may not work on all Pentium based boards.
227 People using multiprocessor machines who say Y here should also say
228 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
229 Management" code will be disabled if you say Y here.
231 See also <file:Documentation/i386/IO-APIC.txt>,
232 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
233 <http://www.tldp.org/docs.html#howto>.
235 If you don't know what to do here, say N.
237 config X86_HAS_BOOT_CPU_ID
239 depends on X86_VOYAGER
242 bool "Support sparse irq numbering"
243 depends on PCI_MSI || HT_IRQ
245 This enables support for sparse irq, esp for msi/msi-x. You may need
246 if you have lots of cards supports msi-x installed.
248 If you don't know what to do here, say Y.
250 config NUMA_MIGRATE_IRQ_DESC
251 bool "Move irq desc when changing irq smp_affinity"
252 depends on SPARSE_IRQ && NUMA
255 This enables moving irq_desc to cpu/node that irq will use handled.
257 If you don't know what to do here, say N.
259 config X86_FIND_SMP_CONFIG
261 depends on X86_MPPARSE || X86_VOYAGER
266 bool "Enable MPS table"
267 depends on X86_LOCAL_APIC
269 For old smp systems that do not have proper acpi support. Newer systems
270 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
276 depends on X86_LOCAL_APIC
280 prompt "Subarchitecture Type"
286 Choose this option if your computer is a standard PC or compatible.
292 Select this for an AMD Elan processor.
294 Do not use this option for K6/Athlon/Opteron processors!
296 If unsure, choose "PC-compatible" instead.
300 depends on X86_32 && (SMP || BROKEN) && !PCI
302 Voyager is an MCA-based 32-way capable SMP architecture proprietary
303 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
307 If you do not specifically know you have a Voyager based machine,
308 say N here, otherwise the kernel you build will not be bootable.
310 config X86_GENERICARCH
311 bool "Generic architecture"
314 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
315 subarchitectures. It is intended for a generic binary kernel.
316 if you select them all, kernel will probe it one by one. and will
322 bool "NUMAQ (IBM/Sequent)"
323 depends on SMP && X86_32 && PCI && X86_MPPARSE
326 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
327 NUMA multiquad box. This changes the way that processors are
328 bootstrapped, and uses Clustered Logical APIC addressing mode instead
329 of Flat Logical. You will need a new lynxer.elf file to flash your
330 firmware with - send email to <Martin.Bligh@us.ibm.com>.
333 bool "Summit/EXA (IBM x440)"
334 depends on X86_32 && SMP
336 This option is needed for IBM systems that use the Summit/EXA chipset.
337 In particular, it is needed for the x440.
340 bool "Support for Unisys ES7000 IA32 series"
341 depends on X86_32 && SMP
343 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
344 supposed to run on an IA32-based Unisys ES7000 system.
347 bool "Support for big SMP systems with more than 8 CPUs"
348 depends on X86_32 && SMP
350 This option is needed for the systems that have more than 8 CPUs
351 and if the system is not of any sub-arch type above.
356 bool "Support for ScaleMP vSMP"
358 depends on X86_64 && PCI
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.
367 bool "SGI 320/540 (Visual Workstation)"
368 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
370 The SGI Visual Workstation series is an IA32-based workstation
371 based on SGI systems chips with some legacy PC hardware attached.
373 Say Y here to create a kernel to run on the SGI 320 or 540.
375 A kernel compiled for the Visual Workstation will run on general
376 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
379 bool "RDC R-321x SoC"
382 select X86_REBOOTFIXUPS
384 This option is needed for RDC R-321x system-on-chip, also known
386 If you don't have one of these chips, you should say N here.
388 config SCHED_NO_NO_OMIT_FRAME_POINTER
390 prompt "Single-depth WCHAN output"
393 Calculate simpler /proc/<PID>/wchan values. If this option
394 is disabled then wchan values will recurse back to the
395 caller function. This provides more accurate wchan values,
396 at the expense of slightly more scheduling overhead.
398 If in doubt, say "Y".
400 menuconfig PARAVIRT_GUEST
401 bool "Paravirtualized guest support"
403 Say Y here to get to see options related to running Linux under
404 various hypervisors. This option alone does not add any kernel code.
406 If you say N, all options in this submenu will be skipped and disabled.
410 source "arch/x86/xen/Kconfig"
413 bool "VMI Guest support"
416 depends on !X86_VOYAGER
418 VMI provides a paravirtualized interface to the VMware ESX server
419 (it could be used by other hypervisors in theory too, but is not
420 at the moment), by linking the kernel to a GPL-ed ROM module
421 provided by the hypervisor.
424 bool "KVM paravirtualized clock"
426 select PARAVIRT_CLOCK
427 depends on !X86_VOYAGER
429 Turning on this option will allow you to run a paravirtualized clock
430 when running over the KVM hypervisor. Instead of relying on a PIT
431 (or probably other) emulation by the underlying device model, the host
432 provides the guest with timing infrastructure such as time of day, and
436 bool "KVM Guest support"
438 depends on !X86_VOYAGER
440 This option enables various optimizations for running under the KVM
443 source "arch/x86/lguest/Kconfig"
446 bool "Enable paravirtualization code"
447 depends on !X86_VOYAGER
449 This changes the kernel so it can modify itself when it is run
450 under a hypervisor, potentially improving performance significantly
451 over full virtualization. However, when run without a hypervisor
452 the kernel is theoretically slower and slightly larger.
454 config PARAVIRT_CLOCK
460 config PARAVIRT_DEBUG
461 bool "paravirt-ops debugging"
462 depends on PARAVIRT && DEBUG_KERNEL
464 Enable to debug paravirt_ops internals. Specifically, BUG if
465 a paravirt_op is missing when it is called.
470 This option adds a kernel parameter 'memtest', which allows memtest
472 memtest=0, mean disabled; -- default
473 memtest=1, mean do 1 test pattern;
475 memtest=4, mean do 4 test patterns.
476 If you are unsure how to answer this question, answer N.
478 config X86_SUMMIT_NUMA
480 depends on X86_32 && NUMA && X86_GENERICARCH
482 config X86_CYCLONE_TIMER
484 depends on X86_GENERICARCH
486 config ES7000_CLUSTERED_APIC
488 depends on SMP && X86_ES7000 && MPENTIUMIII
490 source "arch/x86/Kconfig.cpu"
494 prompt "HPET Timer Support" if X86_32
496 Use the IA-PC HPET (High Precision Event Timer) to manage
497 time in preference to the PIT and RTC, if a HPET is
499 HPET is the next generation timer replacing legacy 8254s.
500 The HPET provides a stable time base on SMP
501 systems, unlike the TSC, but it is more expensive to access,
502 as it is off-chip. You can find the HPET spec at
503 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
505 You can safely choose Y here. However, HPET will only be
506 activated if the platform and the BIOS support this feature.
507 Otherwise the 8254 will be used for timing services.
509 Choose N to continue using the legacy 8254 timer.
511 config HPET_EMULATE_RTC
513 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
515 # Mark as embedded because too many people got it wrong.
516 # The code disables itself when not needed.
519 bool "Enable DMI scanning" if EMBEDDED
521 Enabled scanning of DMI to identify machine quirks. Say Y
522 here unless you have verified that your setup is not
523 affected by entries in the DMI blacklist. Required by PNP
527 bool "GART IOMMU support" if EMBEDDED
531 depends on X86_64 && PCI
533 Support for full DMA access of devices with 32bit memory access only
534 on systems with more than 3GB. This is usually needed for USB,
535 sound, many IDE/SATA chipsets and some other devices.
536 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
537 based hardware IOMMU and a software bounce buffer based IOMMU used
538 on Intel systems and as fallback.
539 The code is only active when needed (enough memory and limited
540 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
544 bool "IBM Calgary IOMMU support"
546 depends on X86_64 && PCI && EXPERIMENTAL
548 Support for hardware IOMMUs in IBM's xSeries x366 and x460
549 systems. Needed to run systems with more than 3GB of memory
550 properly with 32-bit PCI devices that do not support DAC
551 (Double Address Cycle). Calgary also supports bus level
552 isolation, where all DMAs pass through the IOMMU. This
553 prevents them from going anywhere except their intended
554 destination. This catches hard-to-find kernel bugs and
555 mis-behaving drivers and devices that do not use the DMA-API
556 properly to set up their DMA buffers. The IOMMU can be
557 turned off at boot time with the iommu=off parameter.
558 Normally the kernel will make the right choice by itself.
561 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
563 prompt "Should Calgary be enabled by default?"
564 depends on CALGARY_IOMMU
566 Should Calgary be enabled by default? if you choose 'y', Calgary
567 will be used (if it exists). If you choose 'n', Calgary will not be
568 used even if it exists. If you choose 'n' and would like to use
569 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
573 bool "AMD IOMMU support"
576 depends on X86_64 && PCI && ACPI
578 With this option you can enable support for AMD IOMMU hardware in
579 your system. An IOMMU is a hardware component which provides
580 remapping of DMA memory accesses from devices. With an AMD IOMMU you
581 can isolate the the DMA memory of different devices and protect the
582 system from misbehaving device drivers or hardware.
584 You can find out if your system has an AMD IOMMU if you look into
585 your BIOS for an option to enable it or if you have an IVRS ACPI
588 # need this always selected by IOMMU for the VIA workaround
592 Support for software bounce buffers used on x86-64 systems
593 which don't have a hardware IOMMU (e.g. the current generation
594 of Intel's x86-64 CPUs). Using this PCI devices which can only
595 access 32-bits of memory can be used on systems with more than
596 3 GB of memory. If unsure, say Y.
599 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
602 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
603 depends on X86_64 && SMP && BROKEN
606 Configure maximum number of CPUS and NUMA Nodes for this architecture.
610 int "Maximum number of CPUs (2-512)" if !MAXSMP
613 default "4096" if MAXSMP
614 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
617 This allows you to specify the maximum number of CPUs which this
618 kernel will support. The maximum supported value is 512 and the
619 minimum value which makes sense is 2.
621 This is purely to save memory - each supported CPU adds
622 approximately eight kilobytes to the kernel image.
625 bool "SMT (Hyperthreading) scheduler support"
628 SMT scheduler support improves the CPU scheduler's decision making
629 when dealing with Intel Pentium 4 chips with HyperThreading at a
630 cost of slightly increased overhead in some places. If unsure say
635 prompt "Multi-core scheduler support"
638 Multi-core scheduler support improves the CPU scheduler's decision
639 making when dealing with multi-core CPU chips at a cost of slightly
640 increased overhead in some places. If unsure say N here.
642 source "kernel/Kconfig.preempt"
645 bool "Local APIC support on uniprocessors"
646 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
648 A local APIC (Advanced Programmable Interrupt Controller) is an
649 integrated interrupt controller in the CPU. If you have a single-CPU
650 system which has a processor with a local APIC, you can say Y here to
651 enable and use it. If you say Y here even though your machine doesn't
652 have a local APIC, then the kernel will still run with no slowdown at
653 all. The local APIC supports CPU-generated self-interrupts (timer,
654 performance counters), and the NMI watchdog which detects hard
658 bool "IO-APIC support on uniprocessors"
659 depends on X86_UP_APIC
661 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
662 SMP-capable replacement for PC-style interrupt controllers. Most
663 SMP systems and many recent uniprocessor systems have one.
665 If you have a single-CPU system with an IO-APIC, you can say Y here
666 to use it. If you say Y here even though your machine doesn't have
667 an IO-APIC, then the kernel will still run with no slowdown at all.
669 config X86_LOCAL_APIC
671 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
675 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
677 config X86_VISWS_APIC
679 depends on X86_32 && X86_VISWS
682 bool "Machine Check Exception"
683 depends on !X86_VOYAGER
685 Machine Check Exception support allows the processor to notify the
686 kernel if it detects a problem (e.g. overheating, component failure).
687 The action the kernel takes depends on the severity of the problem,
688 ranging from a warning message on the console, to halting the machine.
689 Your processor must be a Pentium or newer to support this - check the
690 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
691 have a design flaw which leads to false MCE events - hence MCE is
692 disabled on all P5 processors, unless explicitly enabled with "mce"
693 as a boot argument. Similarly, if MCE is built in and creates a
694 problem on some new non-standard machine, you can boot with "nomce"
695 to disable it. MCE support simply ignores non-MCE processors like
696 the 386 and 486, so nearly everyone can say Y here.
700 prompt "Intel MCE features"
701 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
703 Additional support for intel specific MCE features such as
708 prompt "AMD MCE features"
709 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
711 Additional support for AMD specific MCE features such as
712 the DRAM Error Threshold.
714 config X86_MCE_NONFATAL
715 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
716 depends on X86_32 && X86_MCE
718 Enabling this feature starts a timer that triggers every 5 seconds which
719 will look at the machine check registers to see if anything happened.
720 Non-fatal problems automatically get corrected (but still logged).
721 Disable this if you don't want to see these messages.
722 Seeing the messages this option prints out may be indicative of dying
723 or out-of-spec (ie, overclocked) hardware.
724 This option only does something on certain CPUs.
725 (AMD Athlon/Duron and Intel Pentium 4)
727 config X86_MCE_P4THERMAL
728 bool "check for P4 thermal throttling interrupt."
729 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
731 Enabling this feature will cause a message to be printed when the P4
732 enters thermal throttling.
735 bool "Enable VM86 support" if EMBEDDED
739 This option is required by programs like DOSEMU to run 16-bit legacy
740 code on X86 processors. It also may be needed by software like
741 XFree86 to initialize some video cards via BIOS. Disabling this
742 option saves about 6k.
745 tristate "Toshiba Laptop support"
748 This adds a driver to safely access the System Management Mode of
749 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
750 not work on models with a Phoenix BIOS. The System Management Mode
751 is used to set the BIOS and power saving options on Toshiba portables.
753 For information on utilities to make use of this driver see the
754 Toshiba Linux utilities web site at:
755 <http://www.buzzard.org.uk/toshiba/>.
757 Say Y if you intend to run this kernel on a Toshiba portable.
761 tristate "Dell laptop support"
763 This adds a driver to safely access the System Management Mode
764 of the CPU on the Dell Inspiron 8000. The System Management Mode
765 is used to read cpu temperature and cooling fan status and to
766 control the fans on the I8K portables.
768 This driver has been tested only on the Inspiron 8000 but it may
769 also work with other Dell laptops. You can force loading on other
770 models by passing the parameter `force=1' to the module. Use at
773 For information on utilities to make use of this driver see the
774 I8K Linux utilities web site at:
775 <http://people.debian.org/~dz/i8k/>
777 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
780 config X86_REBOOTFIXUPS
781 bool "Enable X86 board specific fixups for reboot"
784 This enables chipset and/or board specific fixups to be done
785 in order to get reboot to work correctly. This is only needed on
786 some combinations of hardware and BIOS. The symptom, for which
787 this config is intended, is when reboot ends with a stalled/hung
790 Currently, the only fixup is for the Geode machines using
791 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
793 Say Y if you want to enable the fixup. Currently, it's safe to
794 enable this option even if you don't need it.
798 tristate "/dev/cpu/microcode - microcode support"
801 If you say Y here, you will be able to update the microcode on
802 certain Intel and AMD processors. The Intel support is for the
803 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
804 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
805 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
806 You will obviously need the actual microcode binary data itself
807 which is not shipped with the Linux kernel.
809 This option selects the general module only, you need to select
810 at least one vendor specific module as well.
812 To compile this driver as a module, choose M here: the
813 module will be called microcode.
815 config MICROCODE_INTEL
816 bool "Intel microcode patch loading support"
821 This options enables microcode patch loading support for Intel
824 For latest news and information on obtaining all the required
825 Intel ingredients for this driver, check:
826 <http://www.urbanmyth.org/microcode/>.
829 bool "AMD microcode patch loading support"
833 If you select this option, microcode patch loading support for AMD
834 processors will be enabled.
836 config MICROCODE_OLD_INTERFACE
841 tristate "/dev/cpu/*/msr - Model-specific register support"
843 This device gives privileged processes access to the x86
844 Model-Specific Registers (MSRs). It is a character device with
845 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
846 MSR accesses are directed to a specific CPU on multi-processor
850 tristate "/dev/cpu/*/cpuid - CPU information support"
852 This device gives processes access to the x86 CPUID instruction to
853 be executed on a specific processor. It is a character device
854 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
858 prompt "High Memory Support"
859 default HIGHMEM4G if !X86_NUMAQ
860 default HIGHMEM64G if X86_NUMAQ
865 depends on !X86_NUMAQ
867 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
868 However, the address space of 32-bit x86 processors is only 4
869 Gigabytes large. That means that, if you have a large amount of
870 physical memory, not all of it can be "permanently mapped" by the
871 kernel. The physical memory that's not permanently mapped is called
874 If you are compiling a kernel which will never run on a machine with
875 more than 1 Gigabyte total physical RAM, answer "off" here (default
876 choice and suitable for most users). This will result in a "3GB/1GB"
877 split: 3GB are mapped so that each process sees a 3GB virtual memory
878 space and the remaining part of the 4GB virtual memory space is used
879 by the kernel to permanently map as much physical memory as
882 If the machine has between 1 and 4 Gigabytes physical RAM, then
885 If more than 4 Gigabytes is used then answer "64GB" here. This
886 selection turns Intel PAE (Physical Address Extension) mode on.
887 PAE implements 3-level paging on IA32 processors. PAE is fully
888 supported by Linux, PAE mode is implemented on all recent Intel
889 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
890 then the kernel will not boot on CPUs that don't support PAE!
892 The actual amount of total physical memory will either be
893 auto detected or can be forced by using a kernel command line option
894 such as "mem=256M". (Try "man bootparam" or see the documentation of
895 your boot loader (lilo or loadlin) about how to pass options to the
896 kernel at boot time.)
898 If unsure, say "off".
902 depends on !X86_NUMAQ
904 Select this if you have a 32-bit processor and between 1 and 4
905 gigabytes of physical RAM.
909 depends on !M386 && !M486
912 Select this if you have a 32-bit processor and more than 4
913 gigabytes of physical RAM.
918 depends on EXPERIMENTAL
919 prompt "Memory split" if EMBEDDED
923 Select the desired split between kernel and user memory.
925 If the address range available to the kernel is less than the
926 physical memory installed, the remaining memory will be available
927 as "high memory". Accessing high memory is a little more costly
928 than low memory, as it needs to be mapped into the kernel first.
929 Note that increasing the kernel address space limits the range
930 available to user programs, making the address space there
931 tighter. Selecting anything other than the default 3G/1G split
932 will also likely make your kernel incompatible with binary-only
935 If you are not absolutely sure what you are doing, leave this
939 bool "3G/1G user/kernel split"
940 config VMSPLIT_3G_OPT
942 bool "3G/1G user/kernel split (for full 1G low memory)"
944 bool "2G/2G user/kernel split"
945 config VMSPLIT_2G_OPT
947 bool "2G/2G user/kernel split (for full 2G low memory)"
949 bool "1G/3G user/kernel split"
954 default 0xB0000000 if VMSPLIT_3G_OPT
955 default 0x80000000 if VMSPLIT_2G
956 default 0x78000000 if VMSPLIT_2G_OPT
957 default 0x40000000 if VMSPLIT_1G
963 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
966 bool "PAE (Physical Address Extension) Support"
967 depends on X86_32 && !HIGHMEM4G
969 PAE is required for NX support, and furthermore enables
970 larger swapspace support for non-overcommit purposes. It
971 has the cost of more pagetable lookup overhead, and also
972 consumes more pagetable space per process.
974 config ARCH_PHYS_ADDR_T_64BIT
975 def_bool X86_64 || X86_PAE
977 # Common NUMA Features
979 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
981 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
983 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
985 Enable NUMA (Non Uniform Memory Access) support.
986 The kernel will try to allocate memory used by a CPU on the
987 local memory controller of the CPU and add some more
988 NUMA awareness to the kernel.
990 For 32-bit this is currently highly experimental and should be only
991 used for kernel development. It might also cause boot failures.
992 For 64-bit this is recommended on all multiprocessor Opteron systems.
993 If the system is EM64T, you should say N unless your system is
996 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
997 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1001 prompt "Old style AMD Opteron NUMA detection"
1002 depends on X86_64 && NUMA && PCI
1004 Enable K8 NUMA node topology detection. You should say Y here if
1005 you have a multi processor AMD K8 system. This uses an old
1006 method to read the NUMA configuration directly from the builtin
1007 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1008 instead, which also takes priority if both are compiled in.
1010 config X86_64_ACPI_NUMA
1012 prompt "ACPI NUMA detection"
1013 depends on X86_64 && NUMA && ACPI && PCI
1016 Enable ACPI SRAT based node topology detection.
1018 # Some NUMA nodes have memory ranges that span
1019 # other nodes. Even though a pfn is valid and
1020 # between a node's start and end pfns, it may not
1021 # reside on that node. See memmap_init_zone()
1023 config NODES_SPAN_OTHER_NODES
1025 depends on X86_64_ACPI_NUMA
1028 bool "NUMA emulation"
1029 depends on X86_64 && NUMA
1031 Enable NUMA emulation. A flat machine will be split
1032 into virtual nodes when booted with "numa=fake=N", where N is the
1033 number of nodes. This is only useful for debugging.
1036 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1038 default "9" if MAXSMP
1039 default "6" if X86_64
1040 default "4" if X86_NUMAQ
1042 depends on NEED_MULTIPLE_NODES
1044 Specify the maximum number of NUMA Nodes available on the target
1045 system. Increases memory reserved to accomodate various tables.
1047 config HAVE_ARCH_BOOTMEM_NODE
1049 depends on X86_32 && NUMA
1051 config ARCH_HAVE_MEMORY_PRESENT
1053 depends on X86_32 && DISCONTIGMEM
1055 config NEED_NODE_MEMMAP_SIZE
1057 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1059 config HAVE_ARCH_ALLOC_REMAP
1061 depends on X86_32 && NUMA
1063 config ARCH_FLATMEM_ENABLE
1065 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1067 config ARCH_DISCONTIGMEM_ENABLE
1069 depends on NUMA && X86_32
1071 config ARCH_DISCONTIGMEM_DEFAULT
1073 depends on NUMA && X86_32
1075 config ARCH_SPARSEMEM_DEFAULT
1079 config ARCH_SPARSEMEM_ENABLE
1081 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH
1082 select SPARSEMEM_STATIC if X86_32
1083 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1085 config ARCH_SELECT_MEMORY_MODEL
1087 depends on ARCH_SPARSEMEM_ENABLE
1089 config ARCH_MEMORY_PROBE
1091 depends on MEMORY_HOTPLUG
1096 bool "Allocate 3rd-level pagetables from highmem"
1097 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1099 The VM uses one page table entry for each page of physical memory.
1100 For systems with a lot of RAM, this can be wasteful of precious
1101 low memory. Setting this option will put user-space page table
1102 entries in high memory.
1104 config X86_CHECK_BIOS_CORRUPTION
1105 bool "Check for low memory corruption"
1107 Periodically check for memory corruption in low memory, which
1108 is suspected to be caused by BIOS. Even when enabled in the
1109 configuration, it is disabled at runtime. Enable it by
1110 setting "memory_corruption_check=1" on the kernel command
1111 line. By default it scans the low 64k of memory every 60
1112 seconds; see the memory_corruption_check_size and
1113 memory_corruption_check_period parameters in
1114 Documentation/kernel-parameters.txt to adjust this.
1116 When enabled with the default parameters, this option has
1117 almost no overhead, as it reserves a relatively small amount
1118 of memory and scans it infrequently. It both detects corruption
1119 and prevents it from affecting the running system.
1121 It is, however, intended as a diagnostic tool; if repeatable
1122 BIOS-originated corruption always affects the same memory,
1123 you can use memmap= to prevent the kernel from using that
1126 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1127 bool "Set the default setting of memory_corruption_check"
1128 depends on X86_CHECK_BIOS_CORRUPTION
1131 Set whether the default state of memory_corruption_check is
1134 config X86_RESERVE_LOW_64K
1135 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1138 Reserve the first 64K of physical RAM on BIOSes that are known
1139 to potentially corrupt that memory range. A numbers of BIOSes are
1140 known to utilize this area during suspend/resume, so it must not
1141 be used by the kernel.
1143 Set this to N if you are absolutely sure that you trust the BIOS
1144 to get all its memory reservations and usages right.
1146 If you have doubts about the BIOS (e.g. suspend/resume does not
1147 work or there's kernel crashes after certain hardware hotplug
1148 events) and it's not AMI or Phoenix, then you might want to enable
1149 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1150 corruption patterns.
1154 config MATH_EMULATION
1156 prompt "Math emulation" if X86_32
1158 Linux can emulate a math coprocessor (used for floating point
1159 operations) if you don't have one. 486DX and Pentium processors have
1160 a math coprocessor built in, 486SX and 386 do not, unless you added
1161 a 487DX or 387, respectively. (The messages during boot time can
1162 give you some hints here ["man dmesg"].) Everyone needs either a
1163 coprocessor or this emulation.
1165 If you don't have a math coprocessor, you need to say Y here; if you
1166 say Y here even though you have a coprocessor, the coprocessor will
1167 be used nevertheless. (This behavior can be changed with the kernel
1168 command line option "no387", which comes handy if your coprocessor
1169 is broken. Try "man bootparam" or see the documentation of your boot
1170 loader (lilo or loadlin) about how to pass options to the kernel at
1171 boot time.) This means that it is a good idea to say Y here if you
1172 intend to use this kernel on different machines.
1174 More information about the internals of the Linux math coprocessor
1175 emulation can be found in <file:arch/x86/math-emu/README>.
1177 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1178 kernel, it won't hurt.
1181 bool "MTRR (Memory Type Range Register) support"
1183 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1184 the Memory Type Range Registers (MTRRs) may be used to control
1185 processor access to memory ranges. This is most useful if you have
1186 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1187 allows bus write transfers to be combined into a larger transfer
1188 before bursting over the PCI/AGP bus. This can increase performance
1189 of image write operations 2.5 times or more. Saying Y here creates a
1190 /proc/mtrr file which may be used to manipulate your processor's
1191 MTRRs. Typically the X server should use this.
1193 This code has a reasonably generic interface so that similar
1194 control registers on other processors can be easily supported
1197 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1198 Registers (ARRs) which provide a similar functionality to MTRRs. For
1199 these, the ARRs are used to emulate the MTRRs.
1200 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1201 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1202 write-combining. All of these processors are supported by this code
1203 and it makes sense to say Y here if you have one of them.
1205 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1206 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1207 can lead to all sorts of problems, so it's good to say Y here.
1209 You can safely say Y even if your machine doesn't have MTRRs, you'll
1210 just add about 9 KB to your kernel.
1212 See <file:Documentation/x86/mtrr.txt> for more information.
1214 config MTRR_SANITIZER
1216 prompt "MTRR cleanup support"
1219 Convert MTRR layout from continuous to discrete, so X drivers can
1220 add writeback entries.
1222 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1223 The largest mtrr entry size for a continous block can be set with
1228 config MTRR_SANITIZER_ENABLE_DEFAULT
1229 int "MTRR cleanup enable value (0-1)"
1232 depends on MTRR_SANITIZER
1234 Enable mtrr cleanup default value
1236 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1237 int "MTRR cleanup spare reg num (0-7)"
1240 depends on MTRR_SANITIZER
1242 mtrr cleanup spare entries default, it can be changed via
1243 mtrr_spare_reg_nr=N on the kernel command line.
1247 prompt "x86 PAT support"
1250 Use PAT attributes to setup page level cache control.
1252 PATs are the modern equivalents of MTRRs and are much more
1253 flexible than MTRRs.
1255 Say N here if you see bootup problems (boot crash, boot hang,
1256 spontaneous reboots) or a non-working video driver.
1261 bool "EFI runtime service support"
1264 This enables the kernel to use EFI runtime services that are
1265 available (such as the EFI variable services).
1267 This option is only useful on systems that have EFI firmware.
1268 In addition, you should use the latest ELILO loader available
1269 at <http://elilo.sourceforge.net> in order to take advantage
1270 of EFI runtime services. However, even with this option, the
1271 resultant kernel should continue to boot on existing non-EFI
1276 prompt "Enable seccomp to safely compute untrusted bytecode"
1278 This kernel feature is useful for number crunching applications
1279 that may need to compute untrusted bytecode during their
1280 execution. By using pipes or other transports made available to
1281 the process as file descriptors supporting the read/write
1282 syscalls, it's possible to isolate those applications in
1283 their own address space using seccomp. Once seccomp is
1284 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1285 and the task is only allowed to execute a few safe syscalls
1286 defined by each seccomp mode.
1288 If unsure, say Y. Only embedded should say N here.
1290 config CC_STACKPROTECTOR
1291 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1292 depends on X86_64 && EXPERIMENTAL && BROKEN
1294 This option turns on the -fstack-protector GCC feature. This
1295 feature puts, at the beginning of critical functions, a canary
1296 value on the stack just before the return address, and validates
1297 the value just before actually returning. Stack based buffer
1298 overflows (that need to overwrite this return address) now also
1299 overwrite the canary, which gets detected and the attack is then
1300 neutralized via a kernel panic.
1302 This feature requires gcc version 4.2 or above, or a distribution
1303 gcc with the feature backported. Older versions are automatically
1304 detected and for those versions, this configuration option is ignored.
1306 config CC_STACKPROTECTOR_ALL
1307 bool "Use stack-protector for all functions"
1308 depends on CC_STACKPROTECTOR
1310 Normally, GCC only inserts the canary value protection for
1311 functions that use large-ish on-stack buffers. By enabling
1312 this option, GCC will be asked to do this for ALL functions.
1314 source kernel/Kconfig.hz
1317 bool "kexec system call"
1318 depends on X86_BIOS_REBOOT
1320 kexec is a system call that implements the ability to shutdown your
1321 current kernel, and to start another kernel. It is like a reboot
1322 but it is independent of the system firmware. And like a reboot
1323 you can start any kernel with it, not just Linux.
1325 The name comes from the similarity to the exec system call.
1327 It is an ongoing process to be certain the hardware in a machine
1328 is properly shutdown, so do not be surprised if this code does not
1329 initially work for you. It may help to enable device hotplugging
1330 support. As of this writing the exact hardware interface is
1331 strongly in flux, so no good recommendation can be made.
1334 bool "kernel crash dumps"
1335 depends on X86_64 || (X86_32 && HIGHMEM)
1337 Generate crash dump after being started by kexec.
1338 This should be normally only set in special crash dump kernels
1339 which are loaded in the main kernel with kexec-tools into
1340 a specially reserved region and then later executed after
1341 a crash by kdump/kexec. The crash dump kernel must be compiled
1342 to a memory address not used by the main kernel or BIOS using
1343 PHYSICAL_START, or it must be built as a relocatable image
1344 (CONFIG_RELOCATABLE=y).
1345 For more details see Documentation/kdump/kdump.txt
1348 bool "kexec jump (EXPERIMENTAL)"
1349 depends on EXPERIMENTAL
1350 depends on KEXEC && HIBERNATION && X86_32
1352 Jump between original kernel and kexeced kernel and invoke
1353 code in physical address mode via KEXEC
1355 config PHYSICAL_START
1356 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1357 default "0x1000000" if X86_NUMAQ
1358 default "0x200000" if X86_64
1361 This gives the physical address where the kernel is loaded.
1363 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1364 bzImage will decompress itself to above physical address and
1365 run from there. Otherwise, bzImage will run from the address where
1366 it has been loaded by the boot loader and will ignore above physical
1369 In normal kdump cases one does not have to set/change this option
1370 as now bzImage can be compiled as a completely relocatable image
1371 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1372 address. This option is mainly useful for the folks who don't want
1373 to use a bzImage for capturing the crash dump and want to use a
1374 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1375 to be specifically compiled to run from a specific memory area
1376 (normally a reserved region) and this option comes handy.
1378 So if you are using bzImage for capturing the crash dump, leave
1379 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1380 Otherwise if you plan to use vmlinux for capturing the crash dump
1381 change this value to start of the reserved region (Typically 16MB
1382 0x1000000). In other words, it can be set based on the "X" value as
1383 specified in the "crashkernel=YM@XM" command line boot parameter
1384 passed to the panic-ed kernel. Typically this parameter is set as
1385 crashkernel=64M@16M. Please take a look at
1386 Documentation/kdump/kdump.txt for more details about crash dumps.
1388 Usage of bzImage for capturing the crash dump is recommended as
1389 one does not have to build two kernels. Same kernel can be used
1390 as production kernel and capture kernel. Above option should have
1391 gone away after relocatable bzImage support is introduced. But it
1392 is present because there are users out there who continue to use
1393 vmlinux for dump capture. This option should go away down the
1396 Don't change this unless you know what you are doing.
1399 bool "Build a relocatable kernel (EXPERIMENTAL)"
1400 depends on EXPERIMENTAL
1402 This builds a kernel image that retains relocation information
1403 so it can be loaded someplace besides the default 1MB.
1404 The relocations tend to make the kernel binary about 10% larger,
1405 but are discarded at runtime.
1407 One use is for the kexec on panic case where the recovery kernel
1408 must live at a different physical address than the primary
1411 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1412 it has been loaded at and the compile time physical address
1413 (CONFIG_PHYSICAL_START) is ignored.
1415 config PHYSICAL_ALIGN
1417 prompt "Alignment value to which kernel should be aligned" if X86_32
1418 default "0x100000" if X86_32
1419 default "0x200000" if X86_64
1420 range 0x2000 0x400000
1422 This value puts the alignment restrictions on physical address
1423 where kernel is loaded and run from. Kernel is compiled for an
1424 address which meets above alignment restriction.
1426 If bootloader loads the kernel at a non-aligned address and
1427 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1428 address aligned to above value and run from there.
1430 If bootloader loads the kernel at a non-aligned address and
1431 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1432 load address and decompress itself to the address it has been
1433 compiled for and run from there. The address for which kernel is
1434 compiled already meets above alignment restrictions. Hence the
1435 end result is that kernel runs from a physical address meeting
1436 above alignment restrictions.
1438 Don't change this unless you know what you are doing.
1441 bool "Support for hot-pluggable CPUs"
1442 depends on SMP && HOTPLUG && !X86_VOYAGER
1444 Say Y here to allow turning CPUs off and on. CPUs can be
1445 controlled through /sys/devices/system/cpu.
1446 ( Note: power management support will enable this option
1447 automatically on SMP systems. )
1448 Say N if you want to disable CPU hotplug.
1452 prompt "Compat VDSO support"
1453 depends on X86_32 || IA32_EMULATION
1455 Map the 32-bit VDSO to the predictable old-style address too.
1457 Say N here if you are running a sufficiently recent glibc
1458 version (2.3.3 or later), to remove the high-mapped
1459 VDSO mapping and to exclusively use the randomized VDSO.
1464 bool "Built-in kernel command line"
1467 Allow for specifying boot arguments to the kernel at
1468 build time. On some systems (e.g. embedded ones), it is
1469 necessary or convenient to provide some or all of the
1470 kernel boot arguments with the kernel itself (that is,
1471 to not rely on the boot loader to provide them.)
1473 To compile command line arguments into the kernel,
1474 set this option to 'Y', then fill in the
1475 the boot arguments in CONFIG_CMDLINE.
1477 Systems with fully functional boot loaders (i.e. non-embedded)
1478 should leave this option set to 'N'.
1481 string "Built-in kernel command string"
1482 depends on CMDLINE_BOOL
1485 Enter arguments here that should be compiled into the kernel
1486 image and used at boot time. If the boot loader provides a
1487 command line at boot time, it is appended to this string to
1488 form the full kernel command line, when the system boots.
1490 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1491 change this behavior.
1493 In most cases, the command line (whether built-in or provided
1494 by the boot loader) should specify the device for the root
1497 config CMDLINE_OVERRIDE
1498 bool "Built-in command line overrides boot loader arguments"
1500 depends on CMDLINE_BOOL
1502 Set this option to 'Y' to have the kernel ignore the boot loader
1503 command line, and use ONLY the built-in command line.
1505 This is used to work around broken boot loaders. This should
1506 be set to 'N' under normal conditions.
1510 config ARCH_ENABLE_MEMORY_HOTPLUG
1512 depends on X86_64 || (X86_32 && HIGHMEM)
1514 config HAVE_ARCH_EARLY_PFN_TO_NID
1518 menu "Power management and ACPI options"
1519 depends on !X86_VOYAGER
1521 config ARCH_HIBERNATION_HEADER
1523 depends on X86_64 && HIBERNATION
1525 source "kernel/power/Kconfig"
1527 source "drivers/acpi/Kconfig"
1532 depends on APM || APM_MODULE
1535 tristate "APM (Advanced Power Management) BIOS support"
1536 depends on X86_32 && PM_SLEEP
1538 APM is a BIOS specification for saving power using several different
1539 techniques. This is mostly useful for battery powered laptops with
1540 APM compliant BIOSes. If you say Y here, the system time will be
1541 reset after a RESUME operation, the /proc/apm device will provide
1542 battery status information, and user-space programs will receive
1543 notification of APM "events" (e.g. battery status change).
1545 If you select "Y" here, you can disable actual use of the APM
1546 BIOS by passing the "apm=off" option to the kernel at boot time.
1548 Note that the APM support is almost completely disabled for
1549 machines with more than one CPU.
1551 In order to use APM, you will need supporting software. For location
1552 and more information, read <file:Documentation/power/pm.txt> and the
1553 Battery Powered Linux mini-HOWTO, available from
1554 <http://www.tldp.org/docs.html#howto>.
1556 This driver does not spin down disk drives (see the hdparm(8)
1557 manpage ("man 8 hdparm") for that), and it doesn't turn off
1558 VESA-compliant "green" monitors.
1560 This driver does not support the TI 4000M TravelMate and the ACER
1561 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1562 desktop machines also don't have compliant BIOSes, and this driver
1563 may cause those machines to panic during the boot phase.
1565 Generally, if you don't have a battery in your machine, there isn't
1566 much point in using this driver and you should say N. If you get
1567 random kernel OOPSes or reboots that don't seem to be related to
1568 anything, try disabling/enabling this option (or disabling/enabling
1571 Some other things you should try when experiencing seemingly random,
1574 1) make sure that you have enough swap space and that it is
1576 2) pass the "no-hlt" option to the kernel
1577 3) switch on floating point emulation in the kernel and pass
1578 the "no387" option to the kernel
1579 4) pass the "floppy=nodma" option to the kernel
1580 5) pass the "mem=4M" option to the kernel (thereby disabling
1581 all but the first 4 MB of RAM)
1582 6) make sure that the CPU is not over clocked.
1583 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1584 8) disable the cache from your BIOS settings
1585 9) install a fan for the video card or exchange video RAM
1586 10) install a better fan for the CPU
1587 11) exchange RAM chips
1588 12) exchange the motherboard.
1590 To compile this driver as a module, choose M here: the
1591 module will be called apm.
1595 config APM_IGNORE_USER_SUSPEND
1596 bool "Ignore USER SUSPEND"
1598 This option will ignore USER SUSPEND requests. On machines with a
1599 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1600 series notebooks, it is necessary to say Y because of a BIOS bug.
1602 config APM_DO_ENABLE
1603 bool "Enable PM at boot time"
1605 Enable APM features at boot time. From page 36 of the APM BIOS
1606 specification: "When disabled, the APM BIOS does not automatically
1607 power manage devices, enter the Standby State, enter the Suspend
1608 State, or take power saving steps in response to CPU Idle calls."
1609 This driver will make CPU Idle calls when Linux is idle (unless this
1610 feature is turned off -- see "Do CPU IDLE calls", below). This
1611 should always save battery power, but more complicated APM features
1612 will be dependent on your BIOS implementation. You may need to turn
1613 this option off if your computer hangs at boot time when using APM
1614 support, or if it beeps continuously instead of suspending. Turn
1615 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1616 T400CDT. This is off by default since most machines do fine without
1620 bool "Make CPU Idle calls when idle"
1622 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1623 On some machines, this can activate improved power savings, such as
1624 a slowed CPU clock rate, when the machine is idle. These idle calls
1625 are made after the idle loop has run for some length of time (e.g.,
1626 333 mS). On some machines, this will cause a hang at boot time or
1627 whenever the CPU becomes idle. (On machines with more than one CPU,
1628 this option does nothing.)
1630 config APM_DISPLAY_BLANK
1631 bool "Enable console blanking using APM"
1633 Enable console blanking using the APM. Some laptops can use this to
1634 turn off the LCD backlight when the screen blanker of the Linux
1635 virtual console blanks the screen. Note that this is only used by
1636 the virtual console screen blanker, and won't turn off the backlight
1637 when using the X Window system. This also doesn't have anything to
1638 do with your VESA-compliant power-saving monitor. Further, this
1639 option doesn't work for all laptops -- it might not turn off your
1640 backlight at all, or it might print a lot of errors to the console,
1641 especially if you are using gpm.
1643 config APM_ALLOW_INTS
1644 bool "Allow interrupts during APM BIOS calls"
1646 Normally we disable external interrupts while we are making calls to
1647 the APM BIOS as a measure to lessen the effects of a badly behaving
1648 BIOS implementation. The BIOS should reenable interrupts if it
1649 needs to. Unfortunately, some BIOSes do not -- especially those in
1650 many of the newer IBM Thinkpads. If you experience hangs when you
1651 suspend, try setting this to Y. Otherwise, say N.
1653 config APM_REAL_MODE_POWER_OFF
1654 bool "Use real mode APM BIOS call to power off"
1656 Use real mode APM BIOS calls to switch off the computer. This is
1657 a work-around for a number of buggy BIOSes. Switch this option on if
1658 your computer crashes instead of powering off properly.
1662 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1664 source "drivers/cpuidle/Kconfig"
1666 source "drivers/idle/Kconfig"
1671 menu "Bus options (PCI etc.)"
1676 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1678 Find out whether you have a PCI motherboard. PCI is the name of a
1679 bus system, i.e. the way the CPU talks to the other stuff inside
1680 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1681 VESA. If you have PCI, say Y, otherwise N.
1684 prompt "PCI access mode"
1685 depends on X86_32 && PCI
1688 On PCI systems, the BIOS can be used to detect the PCI devices and
1689 determine their configuration. However, some old PCI motherboards
1690 have BIOS bugs and may crash if this is done. Also, some embedded
1691 PCI-based systems don't have any BIOS at all. Linux can also try to
1692 detect the PCI hardware directly without using the BIOS.
1694 With this option, you can specify how Linux should detect the
1695 PCI devices. If you choose "BIOS", the BIOS will be used,
1696 if you choose "Direct", the BIOS won't be used, and if you
1697 choose "MMConfig", then PCI Express MMCONFIG will be used.
1698 If you choose "Any", the kernel will try MMCONFIG, then the
1699 direct access method and falls back to the BIOS if that doesn't
1700 work. If unsure, go with the default, which is "Any".
1705 config PCI_GOMMCONFIG
1722 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1724 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1727 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1731 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1735 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1742 bool "Support mmconfig PCI config space access"
1743 depends on X86_64 && PCI && ACPI
1746 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1747 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1749 DMA remapping (DMAR) devices support enables independent address
1750 translations for Direct Memory Access (DMA) from devices.
1751 These DMA remapping devices are reported via ACPI tables
1752 and include PCI device scope covered by these DMA
1757 prompt "Support for Graphics workaround"
1760 Current Graphics drivers tend to use physical address
1761 for DMA and avoid using DMA APIs. Setting this config
1762 option permits the IOMMU driver to set a unity map for
1763 all the OS-visible memory. Hence the driver can continue
1764 to use physical addresses for DMA.
1766 config DMAR_FLOPPY_WA
1770 Floppy disk drivers are know to bypass DMA API calls
1771 thereby failing to work when IOMMU is enabled. This
1772 workaround will setup a 1:1 mapping for the first
1773 16M to make floppy (an ISA device) work.
1776 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1777 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1779 Supports Interrupt remapping for IO-APIC and MSI devices.
1780 To use x2apic mode in the CPU's which support x2APIC enhancements or
1781 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1783 source "drivers/pci/pcie/Kconfig"
1785 source "drivers/pci/Kconfig"
1787 # x86_64 have no ISA slots, but do have ISA-style DMA.
1795 depends on !X86_VOYAGER
1797 Find out whether you have ISA slots on your motherboard. ISA is the
1798 name of a bus system, i.e. the way the CPU talks to the other stuff
1799 inside your box. Other bus systems are PCI, EISA, MicroChannel
1800 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1801 newer boards don't support it. If you have ISA, say Y, otherwise N.
1807 The Extended Industry Standard Architecture (EISA) bus was
1808 developed as an open alternative to the IBM MicroChannel bus.
1810 The EISA bus provided some of the features of the IBM MicroChannel
1811 bus while maintaining backward compatibility with cards made for
1812 the older ISA bus. The EISA bus saw limited use between 1988 and
1813 1995 when it was made obsolete by the PCI bus.
1815 Say Y here if you are building a kernel for an EISA-based machine.
1819 source "drivers/eisa/Kconfig"
1822 bool "MCA support" if !X86_VOYAGER
1823 default y if X86_VOYAGER
1825 MicroChannel Architecture is found in some IBM PS/2 machines and
1826 laptops. It is a bus system similar to PCI or ISA. See
1827 <file:Documentation/mca.txt> (and especially the web page given
1828 there) before attempting to build an MCA bus kernel.
1830 source "drivers/mca/Kconfig"
1833 tristate "NatSemi SCx200 support"
1834 depends on !X86_VOYAGER
1836 This provides basic support for National Semiconductor's
1837 (now AMD's) Geode processors. The driver probes for the
1838 PCI-IDs of several on-chip devices, so its a good dependency
1839 for other scx200_* drivers.
1841 If compiled as a module, the driver is named scx200.
1843 config SCx200HR_TIMER
1844 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1845 depends on SCx200 && GENERIC_TIME
1848 This driver provides a clocksource built upon the on-chip
1849 27MHz high-resolution timer. Its also a workaround for
1850 NSC Geode SC-1100's buggy TSC, which loses time when the
1851 processor goes idle (as is done by the scheduler). The
1852 other workaround is idle=poll boot option.
1854 config GEODE_MFGPT_TIMER
1856 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1857 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1859 This driver provides a clock event source based on the MFGPT
1860 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1861 MFGPTs have a better resolution and max interval than the
1862 generic PIT, and are suitable for use as high-res timers.
1865 bool "One Laptop Per Child support"
1868 Add support for detecting the unique features of the OLPC
1875 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1877 source "drivers/pcmcia/Kconfig"
1879 source "drivers/pci/hotplug/Kconfig"
1884 menu "Executable file formats / Emulations"
1886 source "fs/Kconfig.binfmt"
1888 config IA32_EMULATION
1889 bool "IA32 Emulation"
1891 select COMPAT_BINFMT_ELF
1893 Include code to run 32-bit programs under a 64-bit kernel. You should
1894 likely turn this on, unless you're 100% sure that you don't have any
1895 32-bit programs left.
1898 tristate "IA32 a.out support"
1899 depends on IA32_EMULATION
1901 Support old a.out binaries in the 32bit emulation.
1905 depends on IA32_EMULATION
1907 config COMPAT_FOR_U64_ALIGNMENT
1911 config SYSVIPC_COMPAT
1913 depends on COMPAT && SYSVIPC
1918 config HAVE_ATOMIC_IOMAP
1922 source "net/Kconfig"
1924 source "drivers/Kconfig"
1926 source "drivers/firmware/Kconfig"
1930 source "arch/x86/Kconfig.debug"
1932 source "security/Kconfig"
1934 source "crypto/Kconfig"
1936 source "arch/x86/kvm/Kconfig"
1938 source "lib/Kconfig"
projects / linux-2.6 / blob