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_DYNAMIC_FTRACE
31 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
32 select HAVE_ARCH_KGDB if !X86_VOYAGER
33 select HAVE_ARCH_TRACEHOOK
34 select HAVE_GENERIC_DMA_COHERENT if X86_32
35 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
44 config GENERIC_LOCKBREAK
50 config GENERIC_CMOS_UPDATE
53 config CLOCKSOURCE_WATCHDOG
56 config GENERIC_CLOCKEVENTS
59 config GENERIC_CLOCKEVENTS_BROADCAST
61 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
63 config LOCKDEP_SUPPORT
66 config STACKTRACE_SUPPORT
69 config HAVE_LATENCYTOP_SUPPORT
72 config FAST_CMPXCHG_LOCAL
85 config GENERIC_ISA_DMA
95 config GENERIC_HWEIGHT
101 config ARCH_MAY_HAVE_PC_FDC
104 config RWSEM_GENERIC_SPINLOCK
107 config RWSEM_XCHGADD_ALGORITHM
110 config ARCH_HAS_ILOG2_U32
113 config ARCH_HAS_ILOG2_U64
116 config ARCH_HAS_CPU_IDLE_WAIT
119 config GENERIC_CALIBRATE_DELAY
122 config GENERIC_TIME_VSYSCALL
126 config ARCH_HAS_CPU_RELAX
129 config ARCH_HAS_CACHE_LINE_SIZE
132 config HAVE_SETUP_PER_CPU_AREA
133 def_bool X86_64_SMP || (X86_SMP && !X86_VOYAGER)
135 config HAVE_CPUMASK_OF_CPU_MAP
138 config ARCH_HIBERNATION_POSSIBLE
140 depends on !SMP || !X86_VOYAGER
142 config ARCH_SUSPEND_POSSIBLE
144 depends on !X86_VOYAGER
150 config ARCH_POPULATES_NODE_MAP
157 config ARCH_SUPPORTS_OPTIMIZED_INLINING
160 # Use the generic interrupt handling code in kernel/irq/:
161 config GENERIC_HARDIRQS
165 config GENERIC_IRQ_PROBE
169 config GENERIC_PENDING_IRQ
171 depends on GENERIC_HARDIRQS && SMP
176 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
177 select USE_GENERIC_SMP_HELPERS
182 depends on X86_32 && SMP
186 depends on X86_64 && SMP
191 depends on (X86_32 && !X86_VOYAGER) || X86_64
194 config X86_BIOS_REBOOT
196 depends on !X86_VOYAGER
199 config X86_TRAMPOLINE
201 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
206 source "init/Kconfig"
208 menu "Processor type and features"
210 source "kernel/time/Kconfig"
213 bool "Symmetric multi-processing support"
215 This enables support for systems with more than one CPU. If you have
216 a system with only one CPU, like most personal computers, say N. If
217 you have a system with more than one CPU, say Y.
219 If you say N here, the kernel will run on single and multiprocessor
220 machines, but will use only one CPU of a multiprocessor machine. If
221 you say Y here, the kernel will run on many, but not all,
222 singleprocessor machines. On a singleprocessor machine, the kernel
223 will run faster if you say N here.
225 Note that if you say Y here and choose architecture "586" or
226 "Pentium" under "Processor family", the kernel will not work on 486
227 architectures. Similarly, multiprocessor kernels for the "PPro"
228 architecture may not work on all Pentium based boards.
230 People using multiprocessor machines who say Y here should also say
231 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
232 Management" code will be disabled if you say Y here.
234 See also <file:Documentation/i386/IO-APIC.txt>,
235 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
236 <http://www.tldp.org/docs.html#howto>.
238 If you don't know what to do here, say N.
240 config HAVE_SPARSE_IRQ
241 bool "Support sparse irq numbering"
242 depends on PCI_MSI || HT_IRQ
245 This enables support for sparse irq, esp for msi/msi-x. the irq
246 number will be bus/dev/fn + 12bit. You may need if you have lots of
247 cards supports msi-x installed.
249 If you don't know what to do here, say Y.
251 config X86_FIND_SMP_CONFIG
253 depends on X86_MPPARSE || X86_VOYAGER
258 bool "Enable MPS table"
259 depends on X86_LOCAL_APIC
261 For old smp systems that do not have proper acpi support. Newer systems
262 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
268 depends on X86_LOCAL_APIC
272 prompt "Subarchitecture Type"
278 Choose this option if your computer is a standard PC or compatible.
284 Select this for an AMD Elan processor.
286 Do not use this option for K6/Athlon/Opteron processors!
288 If unsure, choose "PC-compatible" instead.
292 depends on X86_32 && (SMP || BROKEN) && !PCI
294 Voyager is an MCA-based 32-way capable SMP architecture proprietary
295 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
299 If you do not specifically know you have a Voyager based machine,
300 say N here, otherwise the kernel you build will not be bootable.
302 config X86_GENERICARCH
303 bool "Generic architecture"
306 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
307 subarchitectures. It is intended for a generic binary kernel.
308 if you select them all, kernel will probe it one by one. and will
314 bool "NUMAQ (IBM/Sequent)"
315 depends on SMP && X86_32 && PCI && X86_MPPARSE
318 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
319 NUMA multiquad box. This changes the way that processors are
320 bootstrapped, and uses Clustered Logical APIC addressing mode instead
321 of Flat Logical. You will need a new lynxer.elf file to flash your
322 firmware with - send email to <Martin.Bligh@us.ibm.com>.
325 bool "Summit/EXA (IBM x440)"
326 depends on X86_32 && SMP
328 This option is needed for IBM systems that use the Summit/EXA chipset.
329 In particular, it is needed for the x440.
332 bool "Support for Unisys ES7000 IA32 series"
333 depends on X86_32 && SMP
335 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
336 supposed to run on an IA32-based Unisys ES7000 system.
339 bool "Support for big SMP systems with more than 8 CPUs"
340 depends on X86_32 && SMP
342 This option is needed for the systems that have more than 8 CPUs
343 and if the system is not of any sub-arch type above.
348 bool "Support for ScaleMP vSMP"
350 depends on X86_64 && PCI
352 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
353 supposed to run on these EM64T-based machines. Only choose this option
354 if you have one of these machines.
359 bool "SGI 320/540 (Visual Workstation)"
360 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
362 The SGI Visual Workstation series is an IA32-based workstation
363 based on SGI systems chips with some legacy PC hardware attached.
365 Say Y here to create a kernel to run on the SGI 320 or 540.
367 A kernel compiled for the Visual Workstation will run on general
368 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
371 bool "RDC R-321x SoC"
374 select X86_REBOOTFIXUPS
376 This option is needed for RDC R-321x system-on-chip, also known
378 If you don't have one of these chips, you should say N here.
380 config SCHED_NO_NO_OMIT_FRAME_POINTER
382 prompt "Single-depth WCHAN output"
385 Calculate simpler /proc/<PID>/wchan values. If this option
386 is disabled then wchan values will recurse back to the
387 caller function. This provides more accurate wchan values,
388 at the expense of slightly more scheduling overhead.
390 If in doubt, say "Y".
392 menuconfig PARAVIRT_GUEST
393 bool "Paravirtualized guest support"
395 Say Y here to get to see options related to running Linux under
396 various hypervisors. This option alone does not add any kernel code.
398 If you say N, all options in this submenu will be skipped and disabled.
402 source "arch/x86/xen/Kconfig"
405 bool "VMI Guest support"
408 depends on !X86_VOYAGER
410 VMI provides a paravirtualized interface to the VMware ESX server
411 (it could be used by other hypervisors in theory too, but is not
412 at the moment), by linking the kernel to a GPL-ed ROM module
413 provided by the hypervisor.
416 bool "KVM paravirtualized clock"
418 select PARAVIRT_CLOCK
419 depends on !X86_VOYAGER
421 Turning on this option will allow you to run a paravirtualized clock
422 when running over the KVM hypervisor. Instead of relying on a PIT
423 (or probably other) emulation by the underlying device model, the host
424 provides the guest with timing infrastructure such as time of day, and
428 bool "KVM Guest support"
430 depends on !X86_VOYAGER
432 This option enables various optimizations for running under the KVM
435 source "arch/x86/lguest/Kconfig"
438 bool "Enable paravirtualization code"
439 depends on !X86_VOYAGER
441 This changes the kernel so it can modify itself when it is run
442 under a hypervisor, potentially improving performance significantly
443 over full virtualization. However, when run without a hypervisor
444 the kernel is theoretically slower and slightly larger.
446 config PARAVIRT_CLOCK
452 config PARAVIRT_DEBUG
453 bool "paravirt-ops debugging"
454 depends on PARAVIRT && DEBUG_KERNEL
456 Enable to debug paravirt_ops internals. Specifically, BUG if
457 a paravirt_op is missing when it is called.
462 This option adds a kernel parameter 'memtest', which allows memtest
464 memtest=0, mean disabled; -- default
465 memtest=1, mean do 1 test pattern;
467 memtest=4, mean do 4 test patterns.
468 If you are unsure how to answer this question, answer N.
470 config X86_SUMMIT_NUMA
472 depends on X86_32 && NUMA && X86_GENERICARCH
474 config X86_CYCLONE_TIMER
476 depends on X86_GENERICARCH
478 config ES7000_CLUSTERED_APIC
480 depends on SMP && X86_ES7000 && MPENTIUMIII
482 source "arch/x86/Kconfig.cpu"
486 prompt "HPET Timer Support" if X86_32
488 Use the IA-PC HPET (High Precision Event Timer) to manage
489 time in preference to the PIT and RTC, if a HPET is
491 HPET is the next generation timer replacing legacy 8254s.
492 The HPET provides a stable time base on SMP
493 systems, unlike the TSC, but it is more expensive to access,
494 as it is off-chip. You can find the HPET spec at
495 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
497 You can safely choose Y here. However, HPET will only be
498 activated if the platform and the BIOS support this feature.
499 Otherwise the 8254 will be used for timing services.
501 Choose N to continue using the legacy 8254 timer.
503 config HPET_EMULATE_RTC
505 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
507 # Mark as embedded because too many people got it wrong.
508 # The code disables itself when not needed.
511 bool "Enable DMI scanning" if EMBEDDED
513 Enabled scanning of DMI to identify machine quirks. Say Y
514 here unless you have verified that your setup is not
515 affected by entries in the DMI blacklist. Required by PNP
519 bool "GART IOMMU support" if EMBEDDED
523 depends on X86_64 && PCI
525 Support for full DMA access of devices with 32bit memory access only
526 on systems with more than 3GB. This is usually needed for USB,
527 sound, many IDE/SATA chipsets and some other devices.
528 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
529 based hardware IOMMU and a software bounce buffer based IOMMU used
530 on Intel systems and as fallback.
531 The code is only active when needed (enough memory and limited
532 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
536 bool "IBM Calgary IOMMU support"
538 depends on X86_64 && PCI && EXPERIMENTAL
540 Support for hardware IOMMUs in IBM's xSeries x366 and x460
541 systems. Needed to run systems with more than 3GB of memory
542 properly with 32-bit PCI devices that do not support DAC
543 (Double Address Cycle). Calgary also supports bus level
544 isolation, where all DMAs pass through the IOMMU. This
545 prevents them from going anywhere except their intended
546 destination. This catches hard-to-find kernel bugs and
547 mis-behaving drivers and devices that do not use the DMA-API
548 properly to set up their DMA buffers. The IOMMU can be
549 turned off at boot time with the iommu=off parameter.
550 Normally the kernel will make the right choice by itself.
553 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
555 prompt "Should Calgary be enabled by default?"
556 depends on CALGARY_IOMMU
558 Should Calgary be enabled by default? if you choose 'y', Calgary
559 will be used (if it exists). If you choose 'n', Calgary will not be
560 used even if it exists. If you choose 'n' and would like to use
561 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
565 bool "AMD IOMMU support"
568 depends on X86_64 && PCI && ACPI
570 With this option you can enable support for AMD IOMMU hardware in
571 your system. An IOMMU is a hardware component which provides
572 remapping of DMA memory accesses from devices. With an AMD IOMMU you
573 can isolate the the DMA memory of different devices and protect the
574 system from misbehaving device drivers or hardware.
576 You can find out if your system has an AMD IOMMU if you look into
577 your BIOS for an option to enable it or if you have an IVRS ACPI
580 # need this always selected by IOMMU for the VIA workaround
584 Support for software bounce buffers used on x86-64 systems
585 which don't have a hardware IOMMU (e.g. the current generation
586 of Intel's x86-64 CPUs). Using this PCI devices which can only
587 access 32-bits of memory can be used on systems with more than
588 3 GB of memory. If unsure, say Y.
591 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
594 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
595 depends on X86_64 && SMP && BROKEN
598 Configure maximum number of CPUS and NUMA Nodes for this architecture.
602 int "Maximum number of CPUs (2-512)" if !MAXSMP
605 default "4096" if MAXSMP
606 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
609 This allows you to specify the maximum number of CPUs which this
610 kernel will support. The maximum supported value is 512 and the
611 minimum value which makes sense is 2.
613 This is purely to save memory - each supported CPU adds
614 approximately eight kilobytes to the kernel image.
617 bool "SMT (Hyperthreading) scheduler support"
620 SMT scheduler support improves the CPU scheduler's decision making
621 when dealing with Intel Pentium 4 chips with HyperThreading at a
622 cost of slightly increased overhead in some places. If unsure say
627 prompt "Multi-core scheduler support"
630 Multi-core scheduler support improves the CPU scheduler's decision
631 making when dealing with multi-core CPU chips at a cost of slightly
632 increased overhead in some places. If unsure say N here.
634 source "kernel/Kconfig.preempt"
637 bool "Local APIC support on uniprocessors"
638 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
640 A local APIC (Advanced Programmable Interrupt Controller) is an
641 integrated interrupt controller in the CPU. If you have a single-CPU
642 system which has a processor with a local APIC, you can say Y here to
643 enable and use it. If you say Y here even though your machine doesn't
644 have a local APIC, then the kernel will still run with no slowdown at
645 all. The local APIC supports CPU-generated self-interrupts (timer,
646 performance counters), and the NMI watchdog which detects hard
650 bool "IO-APIC support on uniprocessors"
651 depends on X86_UP_APIC
653 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
654 SMP-capable replacement for PC-style interrupt controllers. Most
655 SMP systems and many recent uniprocessor systems have one.
657 If you have a single-CPU system with an IO-APIC, you can say Y here
658 to use it. If you say Y here even though your machine doesn't have
659 an IO-APIC, then the kernel will still run with no slowdown at all.
661 config X86_LOCAL_APIC
663 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
667 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
669 config X86_VISWS_APIC
671 depends on X86_32 && X86_VISWS
674 bool "Machine Check Exception"
675 depends on !X86_VOYAGER
677 Machine Check Exception support allows the processor to notify the
678 kernel if it detects a problem (e.g. overheating, component failure).
679 The action the kernel takes depends on the severity of the problem,
680 ranging from a warning message on the console, to halting the machine.
681 Your processor must be a Pentium or newer to support this - check the
682 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
683 have a design flaw which leads to false MCE events - hence MCE is
684 disabled on all P5 processors, unless explicitly enabled with "mce"
685 as a boot argument. Similarly, if MCE is built in and creates a
686 problem on some new non-standard machine, you can boot with "nomce"
687 to disable it. MCE support simply ignores non-MCE processors like
688 the 386 and 486, so nearly everyone can say Y here.
692 prompt "Intel MCE features"
693 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
695 Additional support for intel specific MCE features such as
700 prompt "AMD MCE features"
701 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
703 Additional support for AMD specific MCE features such as
704 the DRAM Error Threshold.
706 config X86_MCE_NONFATAL
707 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
708 depends on X86_32 && X86_MCE
710 Enabling this feature starts a timer that triggers every 5 seconds which
711 will look at the machine check registers to see if anything happened.
712 Non-fatal problems automatically get corrected (but still logged).
713 Disable this if you don't want to see these messages.
714 Seeing the messages this option prints out may be indicative of dying
715 or out-of-spec (ie, overclocked) hardware.
716 This option only does something on certain CPUs.
717 (AMD Athlon/Duron and Intel Pentium 4)
719 config X86_MCE_P4THERMAL
720 bool "check for P4 thermal throttling interrupt."
721 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
723 Enabling this feature will cause a message to be printed when the P4
724 enters thermal throttling.
727 bool "Enable VM86 support" if EMBEDDED
731 This option is required by programs like DOSEMU to run 16-bit legacy
732 code on X86 processors. It also may be needed by software like
733 XFree86 to initialize some video cards via BIOS. Disabling this
734 option saves about 6k.
737 tristate "Toshiba Laptop support"
740 This adds a driver to safely access the System Management Mode of
741 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
742 not work on models with a Phoenix BIOS. The System Management Mode
743 is used to set the BIOS and power saving options on Toshiba portables.
745 For information on utilities to make use of this driver see the
746 Toshiba Linux utilities web site at:
747 <http://www.buzzard.org.uk/toshiba/>.
749 Say Y if you intend to run this kernel on a Toshiba portable.
753 tristate "Dell laptop support"
755 This adds a driver to safely access the System Management Mode
756 of the CPU on the Dell Inspiron 8000. The System Management Mode
757 is used to read cpu temperature and cooling fan status and to
758 control the fans on the I8K portables.
760 This driver has been tested only on the Inspiron 8000 but it may
761 also work with other Dell laptops. You can force loading on other
762 models by passing the parameter `force=1' to the module. Use at
765 For information on utilities to make use of this driver see the
766 I8K Linux utilities web site at:
767 <http://people.debian.org/~dz/i8k/>
769 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
772 config X86_REBOOTFIXUPS
774 prompt "Enable X86 board specific fixups for reboot"
775 depends on X86_32 && X86
777 This enables chipset and/or board specific fixups to be done
778 in order to get reboot to work correctly. This is only needed on
779 some combinations of hardware and BIOS. The symptom, for which
780 this config is intended, is when reboot ends with a stalled/hung
783 Currently, the only fixup is for the Geode machines using
784 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
786 Say Y if you want to enable the fixup. Currently, it's safe to
787 enable this option even if you don't need it.
791 tristate "/dev/cpu/microcode - microcode support"
794 If you say Y here, you will be able to update the microcode on
795 certain Intel and AMD processors. The Intel support is for the
796 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
797 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
798 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
799 You will obviously need the actual microcode binary data itself
800 which is not shipped with the Linux kernel.
802 This option selects the general module only, you need to select
803 at least one vendor specific module as well.
805 To compile this driver as a module, choose M here: the
806 module will be called microcode.
808 config MICROCODE_INTEL
809 bool "Intel microcode patch loading support"
814 This options enables microcode patch loading support for Intel
817 For latest news and information on obtaining all the required
818 Intel ingredients for this driver, check:
819 <http://www.urbanmyth.org/microcode/>.
822 bool "AMD microcode patch loading support"
826 If you select this option, microcode patch loading support for AMD
827 processors will be enabled.
829 config MICROCODE_OLD_INTERFACE
834 tristate "/dev/cpu/*/msr - Model-specific register support"
836 This device gives privileged processes access to the x86
837 Model-Specific Registers (MSRs). It is a character device with
838 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
839 MSR accesses are directed to a specific CPU on multi-processor
843 tristate "/dev/cpu/*/cpuid - CPU information support"
845 This device gives processes access to the x86 CPUID instruction to
846 be executed on a specific processor. It is a character device
847 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
851 prompt "High Memory Support"
852 default HIGHMEM4G if !X86_NUMAQ
853 default HIGHMEM64G if X86_NUMAQ
858 depends on !X86_NUMAQ
860 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
861 However, the address space of 32-bit x86 processors is only 4
862 Gigabytes large. That means that, if you have a large amount of
863 physical memory, not all of it can be "permanently mapped" by the
864 kernel. The physical memory that's not permanently mapped is called
867 If you are compiling a kernel which will never run on a machine with
868 more than 1 Gigabyte total physical RAM, answer "off" here (default
869 choice and suitable for most users). This will result in a "3GB/1GB"
870 split: 3GB are mapped so that each process sees a 3GB virtual memory
871 space and the remaining part of the 4GB virtual memory space is used
872 by the kernel to permanently map as much physical memory as
875 If the machine has between 1 and 4 Gigabytes physical RAM, then
878 If more than 4 Gigabytes is used then answer "64GB" here. This
879 selection turns Intel PAE (Physical Address Extension) mode on.
880 PAE implements 3-level paging on IA32 processors. PAE is fully
881 supported by Linux, PAE mode is implemented on all recent Intel
882 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
883 then the kernel will not boot on CPUs that don't support PAE!
885 The actual amount of total physical memory will either be
886 auto detected or can be forced by using a kernel command line option
887 such as "mem=256M". (Try "man bootparam" or see the documentation of
888 your boot loader (lilo or loadlin) about how to pass options to the
889 kernel at boot time.)
891 If unsure, say "off".
895 depends on !X86_NUMAQ
897 Select this if you have a 32-bit processor and between 1 and 4
898 gigabytes of physical RAM.
902 depends on !M386 && !M486
905 Select this if you have a 32-bit processor and more than 4
906 gigabytes of physical RAM.
911 depends on EXPERIMENTAL
912 prompt "Memory split" if EMBEDDED
916 Select the desired split between kernel and user memory.
918 If the address range available to the kernel is less than the
919 physical memory installed, the remaining memory will be available
920 as "high memory". Accessing high memory is a little more costly
921 than low memory, as it needs to be mapped into the kernel first.
922 Note that increasing the kernel address space limits the range
923 available to user programs, making the address space there
924 tighter. Selecting anything other than the default 3G/1G split
925 will also likely make your kernel incompatible with binary-only
928 If you are not absolutely sure what you are doing, leave this
932 bool "3G/1G user/kernel split"
933 config VMSPLIT_3G_OPT
935 bool "3G/1G user/kernel split (for full 1G low memory)"
937 bool "2G/2G user/kernel split"
938 config VMSPLIT_2G_OPT
940 bool "2G/2G user/kernel split (for full 2G low memory)"
942 bool "1G/3G user/kernel split"
947 default 0xB0000000 if VMSPLIT_3G_OPT
948 default 0x80000000 if VMSPLIT_2G
949 default 0x78000000 if VMSPLIT_2G_OPT
950 default 0x40000000 if VMSPLIT_1G
956 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
960 prompt "PAE (Physical Address Extension) Support"
961 depends on X86_32 && !HIGHMEM4G
962 select RESOURCES_64BIT
964 PAE is required for NX support, and furthermore enables
965 larger swapspace support for non-overcommit purposes. It
966 has the cost of more pagetable lookup overhead, and also
967 consumes more pagetable space per process.
969 # Common NUMA Features
971 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
973 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
975 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
977 Enable NUMA (Non Uniform Memory Access) support.
978 The kernel will try to allocate memory used by a CPU on the
979 local memory controller of the CPU and add some more
980 NUMA awareness to the kernel.
982 For 32-bit this is currently highly experimental and should be only
983 used for kernel development. It might also cause boot failures.
984 For 64-bit this is recommended on all multiprocessor Opteron systems.
985 If the system is EM64T, you should say N unless your system is
988 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
989 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
993 prompt "Old style AMD Opteron NUMA detection"
994 depends on X86_64 && NUMA && PCI
996 Enable K8 NUMA node topology detection. You should say Y here if
997 you have a multi processor AMD K8 system. This uses an old
998 method to read the NUMA configuration directly from the builtin
999 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1000 instead, which also takes priority if both are compiled in.
1002 config X86_64_ACPI_NUMA
1004 prompt "ACPI NUMA detection"
1005 depends on X86_64 && NUMA && ACPI && PCI
1008 Enable ACPI SRAT based node topology detection.
1010 # Some NUMA nodes have memory ranges that span
1011 # other nodes. Even though a pfn is valid and
1012 # between a node's start and end pfns, it may not
1013 # reside on that node. See memmap_init_zone()
1015 config NODES_SPAN_OTHER_NODES
1017 depends on X86_64_ACPI_NUMA
1020 bool "NUMA emulation"
1021 depends on X86_64 && NUMA
1023 Enable NUMA emulation. A flat machine will be split
1024 into virtual nodes when booted with "numa=fake=N", where N is the
1025 number of nodes. This is only useful for debugging.
1028 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1030 default "9" if MAXSMP
1031 default "6" if X86_64
1032 default "4" if X86_NUMAQ
1034 depends on NEED_MULTIPLE_NODES
1036 Specify the maximum number of NUMA Nodes available on the target
1037 system. Increases memory reserved to accomodate various tables.
1039 config HAVE_ARCH_BOOTMEM_NODE
1041 depends on X86_32 && NUMA
1043 config ARCH_HAVE_MEMORY_PRESENT
1045 depends on X86_32 && DISCONTIGMEM
1047 config NEED_NODE_MEMMAP_SIZE
1049 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1051 config HAVE_ARCH_ALLOC_REMAP
1053 depends on X86_32 && NUMA
1055 config ARCH_FLATMEM_ENABLE
1057 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1059 config ARCH_DISCONTIGMEM_ENABLE
1061 depends on NUMA && X86_32
1063 config ARCH_DISCONTIGMEM_DEFAULT
1065 depends on NUMA && X86_32
1067 config ARCH_SPARSEMEM_DEFAULT
1071 config ARCH_SPARSEMEM_ENABLE
1073 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH
1074 select SPARSEMEM_STATIC if X86_32
1075 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1077 config ARCH_SELECT_MEMORY_MODEL
1079 depends on ARCH_SPARSEMEM_ENABLE
1081 config ARCH_MEMORY_PROBE
1083 depends on MEMORY_HOTPLUG
1088 bool "Allocate 3rd-level pagetables from highmem"
1089 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1091 The VM uses one page table entry for each page of physical memory.
1092 For systems with a lot of RAM, this can be wasteful of precious
1093 low memory. Setting this option will put user-space page table
1094 entries in high memory.
1096 config X86_CHECK_BIOS_CORRUPTION
1097 bool "Check for low memory corruption"
1099 Periodically check for memory corruption in low memory, which
1100 is suspected to be caused by BIOS. Even when enabled in the
1101 configuration, it is disabled at runtime. Enable it by
1102 setting "memory_corruption_check=1" on the kernel command
1103 line. By default it scans the low 64k of memory every 60
1104 seconds; see the memory_corruption_check_size and
1105 memory_corruption_check_period parameters in
1106 Documentation/kernel-parameters.txt to adjust this.
1108 When enabled with the default parameters, this option has
1109 almost no overhead, as it reserves a relatively small amount
1110 of memory and scans it infrequently. It both detects corruption
1111 and prevents it from affecting the running system.
1113 It is, however, intended as a diagnostic tool; if repeatable
1114 BIOS-originated corruption always affects the same memory,
1115 you can use memmap= to prevent the kernel from using that
1118 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1119 bool "Set the default setting of memory_corruption_check"
1120 depends on X86_CHECK_BIOS_CORRUPTION
1123 Set whether the default state of memory_corruption_check is
1126 config X86_RESERVE_LOW_64K
1127 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1130 Reserve the first 64K of physical RAM on BIOSes that are known
1131 to potentially corrupt that memory range. A numbers of BIOSes are
1132 known to utilize this area during suspend/resume, so it must not
1133 be used by the kernel.
1135 Set this to N if you are absolutely sure that you trust the BIOS
1136 to get all its memory reservations and usages right.
1138 If you have doubts about the BIOS (e.g. suspend/resume does not
1139 work or there's kernel crashes after certain hardware hotplug
1140 events) and it's not AMI or Phoenix, then you might want to enable
1141 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1142 corruption patterns.
1146 config MATH_EMULATION
1148 prompt "Math emulation" if X86_32
1150 Linux can emulate a math coprocessor (used for floating point
1151 operations) if you don't have one. 486DX and Pentium processors have
1152 a math coprocessor built in, 486SX and 386 do not, unless you added
1153 a 487DX or 387, respectively. (The messages during boot time can
1154 give you some hints here ["man dmesg"].) Everyone needs either a
1155 coprocessor or this emulation.
1157 If you don't have a math coprocessor, you need to say Y here; if you
1158 say Y here even though you have a coprocessor, the coprocessor will
1159 be used nevertheless. (This behavior can be changed with the kernel
1160 command line option "no387", which comes handy if your coprocessor
1161 is broken. Try "man bootparam" or see the documentation of your boot
1162 loader (lilo or loadlin) about how to pass options to the kernel at
1163 boot time.) This means that it is a good idea to say Y here if you
1164 intend to use this kernel on different machines.
1166 More information about the internals of the Linux math coprocessor
1167 emulation can be found in <file:arch/x86/math-emu/README>.
1169 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1170 kernel, it won't hurt.
1173 bool "MTRR (Memory Type Range Register) support"
1175 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1176 the Memory Type Range Registers (MTRRs) may be used to control
1177 processor access to memory ranges. This is most useful if you have
1178 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1179 allows bus write transfers to be combined into a larger transfer
1180 before bursting over the PCI/AGP bus. This can increase performance
1181 of image write operations 2.5 times or more. Saying Y here creates a
1182 /proc/mtrr file which may be used to manipulate your processor's
1183 MTRRs. Typically the X server should use this.
1185 This code has a reasonably generic interface so that similar
1186 control registers on other processors can be easily supported
1189 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1190 Registers (ARRs) which provide a similar functionality to MTRRs. For
1191 these, the ARRs are used to emulate the MTRRs.
1192 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1193 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1194 write-combining. All of these processors are supported by this code
1195 and it makes sense to say Y here if you have one of them.
1197 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1198 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1199 can lead to all sorts of problems, so it's good to say Y here.
1201 You can safely say Y even if your machine doesn't have MTRRs, you'll
1202 just add about 9 KB to your kernel.
1204 See <file:Documentation/x86/mtrr.txt> for more information.
1206 config MTRR_SANITIZER
1208 prompt "MTRR cleanup support"
1211 Convert MTRR layout from continuous to discrete, so X drivers can
1212 add writeback entries.
1214 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1215 The largest mtrr entry size for a continous block can be set with
1220 config MTRR_SANITIZER_ENABLE_DEFAULT
1221 int "MTRR cleanup enable value (0-1)"
1224 depends on MTRR_SANITIZER
1226 Enable mtrr cleanup default value
1228 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1229 int "MTRR cleanup spare reg num (0-7)"
1232 depends on MTRR_SANITIZER
1234 mtrr cleanup spare entries default, it can be changed via
1235 mtrr_spare_reg_nr=N on the kernel command line.
1239 prompt "x86 PAT support"
1242 Use PAT attributes to setup page level cache control.
1244 PATs are the modern equivalents of MTRRs and are much more
1245 flexible than MTRRs.
1247 Say N here if you see bootup problems (boot crash, boot hang,
1248 spontaneous reboots) or a non-working video driver.
1254 prompt "EFI runtime service support"
1257 This enables the kernel to use EFI runtime services that are
1258 available (such as the EFI variable services).
1260 This option is only useful on systems that have EFI firmware.
1261 In addition, you should use the latest ELILO loader available
1262 at <http://elilo.sourceforge.net> in order to take advantage
1263 of EFI runtime services. However, even with this option, the
1264 resultant kernel should continue to boot on existing non-EFI
1269 prompt "Enable seccomp to safely compute untrusted bytecode"
1271 This kernel feature is useful for number crunching applications
1272 that may need to compute untrusted bytecode during their
1273 execution. By using pipes or other transports made available to
1274 the process as file descriptors supporting the read/write
1275 syscalls, it's possible to isolate those applications in
1276 their own address space using seccomp. Once seccomp is
1277 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1278 and the task is only allowed to execute a few safe syscalls
1279 defined by each seccomp mode.
1281 If unsure, say Y. Only embedded should say N here.
1283 config CC_STACKPROTECTOR
1284 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1285 depends on X86_64 && EXPERIMENTAL && BROKEN
1287 This option turns on the -fstack-protector GCC feature. This
1288 feature puts, at the beginning of critical functions, a canary
1289 value on the stack just before the return address, and validates
1290 the value just before actually returning. Stack based buffer
1291 overflows (that need to overwrite this return address) now also
1292 overwrite the canary, which gets detected and the attack is then
1293 neutralized via a kernel panic.
1295 This feature requires gcc version 4.2 or above, or a distribution
1296 gcc with the feature backported. Older versions are automatically
1297 detected and for those versions, this configuration option is ignored.
1299 config CC_STACKPROTECTOR_ALL
1300 bool "Use stack-protector for all functions"
1301 depends on CC_STACKPROTECTOR
1303 Normally, GCC only inserts the canary value protection for
1304 functions that use large-ish on-stack buffers. By enabling
1305 this option, GCC will be asked to do this for ALL functions.
1307 source kernel/Kconfig.hz
1310 bool "kexec system call"
1311 depends on X86_BIOS_REBOOT
1313 kexec is a system call that implements the ability to shutdown your
1314 current kernel, and to start another kernel. It is like a reboot
1315 but it is independent of the system firmware. And like a reboot
1316 you can start any kernel with it, not just Linux.
1318 The name comes from the similarity to the exec system call.
1320 It is an ongoing process to be certain the hardware in a machine
1321 is properly shutdown, so do not be surprised if this code does not
1322 initially work for you. It may help to enable device hotplugging
1323 support. As of this writing the exact hardware interface is
1324 strongly in flux, so no good recommendation can be made.
1327 bool "kernel crash dumps"
1328 depends on X86_64 || (X86_32 && HIGHMEM)
1330 Generate crash dump after being started by kexec.
1331 This should be normally only set in special crash dump kernels
1332 which are loaded in the main kernel with kexec-tools into
1333 a specially reserved region and then later executed after
1334 a crash by kdump/kexec. The crash dump kernel must be compiled
1335 to a memory address not used by the main kernel or BIOS using
1336 PHYSICAL_START, or it must be built as a relocatable image
1337 (CONFIG_RELOCATABLE=y).
1338 For more details see Documentation/kdump/kdump.txt
1341 bool "kexec jump (EXPERIMENTAL)"
1342 depends on EXPERIMENTAL
1343 depends on KEXEC && HIBERNATION && X86_32
1345 Jump between original kernel and kexeced kernel and invoke
1346 code in physical address mode via KEXEC
1348 config PHYSICAL_START
1349 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1350 default "0x1000000" if X86_NUMAQ
1351 default "0x200000" if X86_64
1354 This gives the physical address where the kernel is loaded.
1356 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1357 bzImage will decompress itself to above physical address and
1358 run from there. Otherwise, bzImage will run from the address where
1359 it has been loaded by the boot loader and will ignore above physical
1362 In normal kdump cases one does not have to set/change this option
1363 as now bzImage can be compiled as a completely relocatable image
1364 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1365 address. This option is mainly useful for the folks who don't want
1366 to use a bzImage for capturing the crash dump and want to use a
1367 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1368 to be specifically compiled to run from a specific memory area
1369 (normally a reserved region) and this option comes handy.
1371 So if you are using bzImage for capturing the crash dump, leave
1372 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1373 Otherwise if you plan to use vmlinux for capturing the crash dump
1374 change this value to start of the reserved region (Typically 16MB
1375 0x1000000). In other words, it can be set based on the "X" value as
1376 specified in the "crashkernel=YM@XM" command line boot parameter
1377 passed to the panic-ed kernel. Typically this parameter is set as
1378 crashkernel=64M@16M. Please take a look at
1379 Documentation/kdump/kdump.txt for more details about crash dumps.
1381 Usage of bzImage for capturing the crash dump is recommended as
1382 one does not have to build two kernels. Same kernel can be used
1383 as production kernel and capture kernel. Above option should have
1384 gone away after relocatable bzImage support is introduced. But it
1385 is present because there are users out there who continue to use
1386 vmlinux for dump capture. This option should go away down the
1389 Don't change this unless you know what you are doing.
1392 bool "Build a relocatable kernel (EXPERIMENTAL)"
1393 depends on EXPERIMENTAL
1395 This builds a kernel image that retains relocation information
1396 so it can be loaded someplace besides the default 1MB.
1397 The relocations tend to make the kernel binary about 10% larger,
1398 but are discarded at runtime.
1400 One use is for the kexec on panic case where the recovery kernel
1401 must live at a different physical address than the primary
1404 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1405 it has been loaded at and the compile time physical address
1406 (CONFIG_PHYSICAL_START) is ignored.
1408 config PHYSICAL_ALIGN
1410 prompt "Alignment value to which kernel should be aligned" if X86_32
1411 default "0x100000" if X86_32
1412 default "0x200000" if X86_64
1413 range 0x2000 0x400000
1415 This value puts the alignment restrictions on physical address
1416 where kernel is loaded and run from. Kernel is compiled for an
1417 address which meets above alignment restriction.
1419 If bootloader loads the kernel at a non-aligned address and
1420 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1421 address aligned to above value and run from there.
1423 If bootloader loads the kernel at a non-aligned address and
1424 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1425 load address and decompress itself to the address it has been
1426 compiled for and run from there. The address for which kernel is
1427 compiled already meets above alignment restrictions. Hence the
1428 end result is that kernel runs from a physical address meeting
1429 above alignment restrictions.
1431 Don't change this unless you know what you are doing.
1434 bool "Support for hot-pluggable CPUs"
1435 depends on SMP && HOTPLUG && !X86_VOYAGER
1437 Say Y here to allow turning CPUs off and on. CPUs can be
1438 controlled through /sys/devices/system/cpu.
1439 ( Note: power management support will enable this option
1440 automatically on SMP systems. )
1441 Say N if you want to disable CPU hotplug.
1445 prompt "Compat VDSO support"
1446 depends on X86_32 || IA32_EMULATION
1448 Map the 32-bit VDSO to the predictable old-style address too.
1450 Say N here if you are running a sufficiently recent glibc
1451 version (2.3.3 or later), to remove the high-mapped
1452 VDSO mapping and to exclusively use the randomized VDSO.
1457 bool "Built-in kernel command line"
1460 Allow for specifying boot arguments to the kernel at
1461 build time. On some systems (e.g. embedded ones), it is
1462 necessary or convenient to provide some or all of the
1463 kernel boot arguments with the kernel itself (that is,
1464 to not rely on the boot loader to provide them.)
1466 To compile command line arguments into the kernel,
1467 set this option to 'Y', then fill in the
1468 the boot arguments in CONFIG_CMDLINE.
1470 Systems with fully functional boot loaders (i.e. non-embedded)
1471 should leave this option set to 'N'.
1474 string "Built-in kernel command string"
1475 depends on CMDLINE_BOOL
1478 Enter arguments here that should be compiled into the kernel
1479 image and used at boot time. If the boot loader provides a
1480 command line at boot time, it is appended to this string to
1481 form the full kernel command line, when the system boots.
1483 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1484 change this behavior.
1486 In most cases, the command line (whether built-in or provided
1487 by the boot loader) should specify the device for the root
1490 config CMDLINE_OVERRIDE
1491 bool "Built-in command line overrides boot loader arguments"
1493 depends on CMDLINE_BOOL
1495 Set this option to 'Y' to have the kernel ignore the boot loader
1496 command line, and use ONLY the built-in command line.
1498 This is used to work around broken boot loaders. This should
1499 be set to 'N' under normal conditions.
1503 config ARCH_ENABLE_MEMORY_HOTPLUG
1505 depends on X86_64 || (X86_32 && HIGHMEM)
1507 config HAVE_ARCH_EARLY_PFN_TO_NID
1511 menu "Power management options"
1512 depends on !X86_VOYAGER
1514 config ARCH_HIBERNATION_HEADER
1516 depends on X86_64 && HIBERNATION
1518 source "kernel/power/Kconfig"
1520 source "drivers/acpi/Kconfig"
1525 depends on APM || APM_MODULE
1528 tristate "APM (Advanced Power Management) BIOS support"
1529 depends on X86_32 && PM_SLEEP
1531 APM is a BIOS specification for saving power using several different
1532 techniques. This is mostly useful for battery powered laptops with
1533 APM compliant BIOSes. If you say Y here, the system time will be
1534 reset after a RESUME operation, the /proc/apm device will provide
1535 battery status information, and user-space programs will receive
1536 notification of APM "events" (e.g. battery status change).
1538 If you select "Y" here, you can disable actual use of the APM
1539 BIOS by passing the "apm=off" option to the kernel at boot time.
1541 Note that the APM support is almost completely disabled for
1542 machines with more than one CPU.
1544 In order to use APM, you will need supporting software. For location
1545 and more information, read <file:Documentation/power/pm.txt> and the
1546 Battery Powered Linux mini-HOWTO, available from
1547 <http://www.tldp.org/docs.html#howto>.
1549 This driver does not spin down disk drives (see the hdparm(8)
1550 manpage ("man 8 hdparm") for that), and it doesn't turn off
1551 VESA-compliant "green" monitors.
1553 This driver does not support the TI 4000M TravelMate and the ACER
1554 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1555 desktop machines also don't have compliant BIOSes, and this driver
1556 may cause those machines to panic during the boot phase.
1558 Generally, if you don't have a battery in your machine, there isn't
1559 much point in using this driver and you should say N. If you get
1560 random kernel OOPSes or reboots that don't seem to be related to
1561 anything, try disabling/enabling this option (or disabling/enabling
1564 Some other things you should try when experiencing seemingly random,
1567 1) make sure that you have enough swap space and that it is
1569 2) pass the "no-hlt" option to the kernel
1570 3) switch on floating point emulation in the kernel and pass
1571 the "no387" option to the kernel
1572 4) pass the "floppy=nodma" option to the kernel
1573 5) pass the "mem=4M" option to the kernel (thereby disabling
1574 all but the first 4 MB of RAM)
1575 6) make sure that the CPU is not over clocked.
1576 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1577 8) disable the cache from your BIOS settings
1578 9) install a fan for the video card or exchange video RAM
1579 10) install a better fan for the CPU
1580 11) exchange RAM chips
1581 12) exchange the motherboard.
1583 To compile this driver as a module, choose M here: the
1584 module will be called apm.
1588 config APM_IGNORE_USER_SUSPEND
1589 bool "Ignore USER SUSPEND"
1591 This option will ignore USER SUSPEND requests. On machines with a
1592 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1593 series notebooks, it is necessary to say Y because of a BIOS bug.
1595 config APM_DO_ENABLE
1596 bool "Enable PM at boot time"
1598 Enable APM features at boot time. From page 36 of the APM BIOS
1599 specification: "When disabled, the APM BIOS does not automatically
1600 power manage devices, enter the Standby State, enter the Suspend
1601 State, or take power saving steps in response to CPU Idle calls."
1602 This driver will make CPU Idle calls when Linux is idle (unless this
1603 feature is turned off -- see "Do CPU IDLE calls", below). This
1604 should always save battery power, but more complicated APM features
1605 will be dependent on your BIOS implementation. You may need to turn
1606 this option off if your computer hangs at boot time when using APM
1607 support, or if it beeps continuously instead of suspending. Turn
1608 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1609 T400CDT. This is off by default since most machines do fine without
1613 bool "Make CPU Idle calls when idle"
1615 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1616 On some machines, this can activate improved power savings, such as
1617 a slowed CPU clock rate, when the machine is idle. These idle calls
1618 are made after the idle loop has run for some length of time (e.g.,
1619 333 mS). On some machines, this will cause a hang at boot time or
1620 whenever the CPU becomes idle. (On machines with more than one CPU,
1621 this option does nothing.)
1623 config APM_DISPLAY_BLANK
1624 bool "Enable console blanking using APM"
1626 Enable console blanking using the APM. Some laptops can use this to
1627 turn off the LCD backlight when the screen blanker of the Linux
1628 virtual console blanks the screen. Note that this is only used by
1629 the virtual console screen blanker, and won't turn off the backlight
1630 when using the X Window system. This also doesn't have anything to
1631 do with your VESA-compliant power-saving monitor. Further, this
1632 option doesn't work for all laptops -- it might not turn off your
1633 backlight at all, or it might print a lot of errors to the console,
1634 especially if you are using gpm.
1636 config APM_ALLOW_INTS
1637 bool "Allow interrupts during APM BIOS calls"
1639 Normally we disable external interrupts while we are making calls to
1640 the APM BIOS as a measure to lessen the effects of a badly behaving
1641 BIOS implementation. The BIOS should reenable interrupts if it
1642 needs to. Unfortunately, some BIOSes do not -- especially those in
1643 many of the newer IBM Thinkpads. If you experience hangs when you
1644 suspend, try setting this to Y. Otherwise, say N.
1646 config APM_REAL_MODE_POWER_OFF
1647 bool "Use real mode APM BIOS call to power off"
1649 Use real mode APM BIOS calls to switch off the computer. This is
1650 a work-around for a number of buggy BIOSes. Switch this option on if
1651 your computer crashes instead of powering off properly.
1655 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1657 source "drivers/cpuidle/Kconfig"
1662 menu "Bus options (PCI etc.)"
1667 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1669 Find out whether you have a PCI motherboard. PCI is the name of a
1670 bus system, i.e. the way the CPU talks to the other stuff inside
1671 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1672 VESA. If you have PCI, say Y, otherwise N.
1675 prompt "PCI access mode"
1676 depends on X86_32 && PCI
1679 On PCI systems, the BIOS can be used to detect the PCI devices and
1680 determine their configuration. However, some old PCI motherboards
1681 have BIOS bugs and may crash if this is done. Also, some embedded
1682 PCI-based systems don't have any BIOS at all. Linux can also try to
1683 detect the PCI hardware directly without using the BIOS.
1685 With this option, you can specify how Linux should detect the
1686 PCI devices. If you choose "BIOS", the BIOS will be used,
1687 if you choose "Direct", the BIOS won't be used, and if you
1688 choose "MMConfig", then PCI Express MMCONFIG will be used.
1689 If you choose "Any", the kernel will try MMCONFIG, then the
1690 direct access method and falls back to the BIOS if that doesn't
1691 work. If unsure, go with the default, which is "Any".
1696 config PCI_GOMMCONFIG
1713 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1715 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1718 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1722 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1726 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1733 bool "Support mmconfig PCI config space access"
1734 depends on X86_64 && PCI && ACPI
1737 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1738 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1740 DMA remapping (DMAR) devices support enables independent address
1741 translations for Direct Memory Access (DMA) from devices.
1742 These DMA remapping devices are reported via ACPI tables
1743 and include PCI device scope covered by these DMA
1748 prompt "Support for Graphics workaround"
1751 Current Graphics drivers tend to use physical address
1752 for DMA and avoid using DMA APIs. Setting this config
1753 option permits the IOMMU driver to set a unity map for
1754 all the OS-visible memory. Hence the driver can continue
1755 to use physical addresses for DMA.
1757 config DMAR_FLOPPY_WA
1761 Floppy disk drivers are know to bypass DMA API calls
1762 thereby failing to work when IOMMU is enabled. This
1763 workaround will setup a 1:1 mapping for the first
1764 16M to make floppy (an ISA device) work.
1767 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1768 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1770 Supports Interrupt remapping for IO-APIC and MSI devices.
1771 To use x2apic mode in the CPU's which support x2APIC enhancements or
1772 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1774 source "drivers/pci/pcie/Kconfig"
1776 source "drivers/pci/Kconfig"
1778 # x86_64 have no ISA slots, but do have ISA-style DMA.
1786 depends on !X86_VOYAGER
1788 Find out whether you have ISA slots on your motherboard. ISA is the
1789 name of a bus system, i.e. the way the CPU talks to the other stuff
1790 inside your box. Other bus systems are PCI, EISA, MicroChannel
1791 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1792 newer boards don't support it. If you have ISA, say Y, otherwise N.
1798 The Extended Industry Standard Architecture (EISA) bus was
1799 developed as an open alternative to the IBM MicroChannel bus.
1801 The EISA bus provided some of the features of the IBM MicroChannel
1802 bus while maintaining backward compatibility with cards made for
1803 the older ISA bus. The EISA bus saw limited use between 1988 and
1804 1995 when it was made obsolete by the PCI bus.
1806 Say Y here if you are building a kernel for an EISA-based machine.
1810 source "drivers/eisa/Kconfig"
1813 bool "MCA support" if !X86_VOYAGER
1814 default y if X86_VOYAGER
1816 MicroChannel Architecture is found in some IBM PS/2 machines and
1817 laptops. It is a bus system similar to PCI or ISA. See
1818 <file:Documentation/mca.txt> (and especially the web page given
1819 there) before attempting to build an MCA bus kernel.
1821 source "drivers/mca/Kconfig"
1824 tristate "NatSemi SCx200 support"
1825 depends on !X86_VOYAGER
1827 This provides basic support for National Semiconductor's
1828 (now AMD's) Geode processors. The driver probes for the
1829 PCI-IDs of several on-chip devices, so its a good dependency
1830 for other scx200_* drivers.
1832 If compiled as a module, the driver is named scx200.
1834 config SCx200HR_TIMER
1835 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1836 depends on SCx200 && GENERIC_TIME
1839 This driver provides a clocksource built upon the on-chip
1840 27MHz high-resolution timer. Its also a workaround for
1841 NSC Geode SC-1100's buggy TSC, which loses time when the
1842 processor goes idle (as is done by the scheduler). The
1843 other workaround is idle=poll boot option.
1845 config GEODE_MFGPT_TIMER
1847 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1848 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1850 This driver provides a clock event source based on the MFGPT
1851 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1852 MFGPTs have a better resolution and max interval than the
1853 generic PIT, and are suitable for use as high-res timers.
1856 bool "One Laptop Per Child support"
1859 Add support for detecting the unique features of the OLPC
1866 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1868 source "drivers/pcmcia/Kconfig"
1870 source "drivers/pci/hotplug/Kconfig"
1875 menu "Executable file formats / Emulations"
1877 source "fs/Kconfig.binfmt"
1879 config IA32_EMULATION
1880 bool "IA32 Emulation"
1882 select COMPAT_BINFMT_ELF
1884 Include code to run 32-bit programs under a 64-bit kernel. You should
1885 likely turn this on, unless you're 100% sure that you don't have any
1886 32-bit programs left.
1889 tristate "IA32 a.out support"
1890 depends on IA32_EMULATION
1892 Support old a.out binaries in the 32bit emulation.
1896 depends on IA32_EMULATION
1898 config COMPAT_FOR_U64_ALIGNMENT
1902 config SYSVIPC_COMPAT
1904 depends on COMPAT && SYSVIPC
1909 source "net/Kconfig"
1911 source "drivers/Kconfig"
1913 source "drivers/firmware/Kconfig"
1917 source "arch/x86/Kconfig.debug"
1919 source "security/Kconfig"
1921 source "crypto/Kconfig"
1923 source "arch/x86/kvm/Kconfig"
1925 source "lib/Kconfig"
projects / linux-2.6 / blob