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
241 config X86_FIND_SMP_CONFIG
243 depends on X86_MPPARSE || X86_VOYAGER
246 bool "Enable MPS table" if ACPI
248 depends on X86_LOCAL_APIC
250 For old smp systems that do not have proper acpi support. Newer systems
251 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
254 prompt "Subarchitecture Type"
260 Choose this option if your computer is a standard PC or compatible.
266 Select this for an AMD Elan processor.
268 Do not use this option for K6/Athlon/Opteron processors!
270 If unsure, choose "PC-compatible" instead.
274 depends on X86_32 && (SMP || BROKEN) && !PCI
276 Voyager is an MCA-based 32-way capable SMP architecture proprietary
277 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
281 If you do not specifically know you have a Voyager based machine,
282 say N here, otherwise the kernel you build will not be bootable.
284 config X86_GENERICARCH
285 bool "Generic architecture"
288 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
289 subarchitectures. It is intended for a generic binary kernel.
290 if you select them all, kernel will probe it one by one. and will
296 bool "NUMAQ (IBM/Sequent)"
297 depends on SMP && X86_32 && PCI && X86_MPPARSE
300 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
301 NUMA multiquad box. This changes the way that processors are
302 bootstrapped, and uses Clustered Logical APIC addressing mode instead
303 of Flat Logical. You will need a new lynxer.elf file to flash your
304 firmware with - send email to <Martin.Bligh@us.ibm.com>.
307 bool "Summit/EXA (IBM x440)"
308 depends on X86_32 && SMP
310 This option is needed for IBM systems that use the Summit/EXA chipset.
311 In particular, it is needed for the x440.
314 bool "Support for Unisys ES7000 IA32 series"
315 depends on X86_32 && SMP
317 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
318 supposed to run on an IA32-based Unisys ES7000 system.
321 bool "Support for big SMP systems with more than 8 CPUs"
322 depends on X86_32 && SMP
324 This option is needed for the systems that have more than 8 CPUs
325 and if the system is not of any sub-arch type above.
330 bool "Support for ScaleMP vSMP"
332 depends on X86_64 && PCI
334 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
335 supposed to run on these EM64T-based machines. Only choose this option
336 if you have one of these machines.
341 bool "SGI 320/540 (Visual Workstation)"
342 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
344 The SGI Visual Workstation series is an IA32-based workstation
345 based on SGI systems chips with some legacy PC hardware attached.
347 Say Y here to create a kernel to run on the SGI 320 or 540.
349 A kernel compiled for the Visual Workstation will run on general
350 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
353 bool "RDC R-321x SoC"
356 select X86_REBOOTFIXUPS
358 This option is needed for RDC R-321x system-on-chip, also known
360 If you don't have one of these chips, you should say N here.
362 config SCHED_NO_NO_OMIT_FRAME_POINTER
364 prompt "Single-depth WCHAN output"
367 Calculate simpler /proc/<PID>/wchan values. If this option
368 is disabled then wchan values will recurse back to the
369 caller function. This provides more accurate wchan values,
370 at the expense of slightly more scheduling overhead.
372 If in doubt, say "Y".
374 menuconfig PARAVIRT_GUEST
375 bool "Paravirtualized guest support"
377 Say Y here to get to see options related to running Linux under
378 various hypervisors. This option alone does not add any kernel code.
380 If you say N, all options in this submenu will be skipped and disabled.
384 source "arch/x86/xen/Kconfig"
387 bool "VMI Guest support"
390 depends on !X86_VOYAGER
392 VMI provides a paravirtualized interface to the VMware ESX server
393 (it could be used by other hypervisors in theory too, but is not
394 at the moment), by linking the kernel to a GPL-ed ROM module
395 provided by the hypervisor.
398 bool "KVM paravirtualized clock"
400 select PARAVIRT_CLOCK
401 depends on !X86_VOYAGER
403 Turning on this option will allow you to run a paravirtualized clock
404 when running over the KVM hypervisor. Instead of relying on a PIT
405 (or probably other) emulation by the underlying device model, the host
406 provides the guest with timing infrastructure such as time of day, and
410 bool "KVM Guest support"
412 depends on !X86_VOYAGER
414 This option enables various optimizations for running under the KVM
417 source "arch/x86/lguest/Kconfig"
420 bool "Enable paravirtualization code"
421 depends on !X86_VOYAGER
423 This changes the kernel so it can modify itself when it is run
424 under a hypervisor, potentially improving performance significantly
425 over full virtualization. However, when run without a hypervisor
426 the kernel is theoretically slower and slightly larger.
428 config PARAVIRT_CLOCK
434 config PARAVIRT_DEBUG
435 bool "paravirt-ops debugging"
436 depends on PARAVIRT && DEBUG_KERNEL
438 Enable to debug paravirt_ops internals. Specifically, BUG if
439 a paravirt_op is missing when it is called.
444 This option adds a kernel parameter 'memtest', which allows memtest
446 memtest=0, mean disabled; -- default
447 memtest=1, mean do 1 test pattern;
449 memtest=4, mean do 4 test patterns.
450 If you are unsure how to answer this question, answer N.
452 config X86_SUMMIT_NUMA
454 depends on X86_32 && NUMA && X86_GENERICARCH
456 config X86_CYCLONE_TIMER
458 depends on X86_GENERICARCH
460 config ES7000_CLUSTERED_APIC
462 depends on SMP && X86_ES7000 && MPENTIUMIII
464 source "arch/x86/Kconfig.cpu"
468 prompt "HPET Timer Support" if X86_32
470 Use the IA-PC HPET (High Precision Event Timer) to manage
471 time in preference to the PIT and RTC, if a HPET is
473 HPET is the next generation timer replacing legacy 8254s.
474 The HPET provides a stable time base on SMP
475 systems, unlike the TSC, but it is more expensive to access,
476 as it is off-chip. You can find the HPET spec at
477 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
479 You can safely choose Y here. However, HPET will only be
480 activated if the platform and the BIOS support this feature.
481 Otherwise the 8254 will be used for timing services.
483 Choose N to continue using the legacy 8254 timer.
485 config HPET_EMULATE_RTC
487 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
489 # Mark as embedded because too many people got it wrong.
490 # The code disables itself when not needed.
493 bool "Enable DMI scanning" if EMBEDDED
495 Enabled scanning of DMI to identify machine quirks. Say Y
496 here unless you have verified that your setup is not
497 affected by entries in the DMI blacklist. Required by PNP
501 bool "GART IOMMU support" if EMBEDDED
505 depends on X86_64 && PCI
507 Support for full DMA access of devices with 32bit memory access only
508 on systems with more than 3GB. This is usually needed for USB,
509 sound, many IDE/SATA chipsets and some other devices.
510 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
511 based hardware IOMMU and a software bounce buffer based IOMMU used
512 on Intel systems and as fallback.
513 The code is only active when needed (enough memory and limited
514 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
518 bool "IBM Calgary IOMMU support"
520 depends on X86_64 && PCI && EXPERIMENTAL
522 Support for hardware IOMMUs in IBM's xSeries x366 and x460
523 systems. Needed to run systems with more than 3GB of memory
524 properly with 32-bit PCI devices that do not support DAC
525 (Double Address Cycle). Calgary also supports bus level
526 isolation, where all DMAs pass through the IOMMU. This
527 prevents them from going anywhere except their intended
528 destination. This catches hard-to-find kernel bugs and
529 mis-behaving drivers and devices that do not use the DMA-API
530 properly to set up their DMA buffers. The IOMMU can be
531 turned off at boot time with the iommu=off parameter.
532 Normally the kernel will make the right choice by itself.
535 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
537 prompt "Should Calgary be enabled by default?"
538 depends on CALGARY_IOMMU
540 Should Calgary be enabled by default? if you choose 'y', Calgary
541 will be used (if it exists). If you choose 'n', Calgary will not be
542 used even if it exists. If you choose 'n' and would like to use
543 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
547 bool "AMD IOMMU support"
550 depends on X86_64 && PCI && ACPI
552 With this option you can enable support for AMD IOMMU hardware in
553 your system. An IOMMU is a hardware component which provides
554 remapping of DMA memory accesses from devices. With an AMD IOMMU you
555 can isolate the the DMA memory of different devices and protect the
556 system from misbehaving device drivers or hardware.
558 You can find out if your system has an AMD IOMMU if you look into
559 your BIOS for an option to enable it or if you have an IVRS ACPI
562 # need this always selected by IOMMU for the VIA workaround
566 Support for software bounce buffers used on x86-64 systems
567 which don't have a hardware IOMMU (e.g. the current generation
568 of Intel's x86-64 CPUs). Using this PCI devices which can only
569 access 32-bits of memory can be used on systems with more than
570 3 GB of memory. If unsure, say Y.
573 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
576 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
577 depends on X86_64 && SMP && BROKEN
580 Configure maximum number of CPUS and NUMA Nodes for this architecture.
584 int "Maximum number of CPUs (2-512)" if !MAXSMP
587 default "4096" if MAXSMP
588 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
591 This allows you to specify the maximum number of CPUs which this
592 kernel will support. The maximum supported value is 512 and the
593 minimum value which makes sense is 2.
595 This is purely to save memory - each supported CPU adds
596 approximately eight kilobytes to the kernel image.
599 bool "SMT (Hyperthreading) scheduler support"
602 SMT scheduler support improves the CPU scheduler's decision making
603 when dealing with Intel Pentium 4 chips with HyperThreading at a
604 cost of slightly increased overhead in some places. If unsure say
609 prompt "Multi-core scheduler support"
612 Multi-core scheduler support improves the CPU scheduler's decision
613 making when dealing with multi-core CPU chips at a cost of slightly
614 increased overhead in some places. If unsure say N here.
616 source "kernel/Kconfig.preempt"
619 bool "Local APIC support on uniprocessors"
620 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
622 A local APIC (Advanced Programmable Interrupt Controller) is an
623 integrated interrupt controller in the CPU. If you have a single-CPU
624 system which has a processor with a local APIC, you can say Y here to
625 enable and use it. If you say Y here even though your machine doesn't
626 have a local APIC, then the kernel will still run with no slowdown at
627 all. The local APIC supports CPU-generated self-interrupts (timer,
628 performance counters), and the NMI watchdog which detects hard
632 bool "IO-APIC support on uniprocessors"
633 depends on X86_UP_APIC
635 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
636 SMP-capable replacement for PC-style interrupt controllers. Most
637 SMP systems and many recent uniprocessor systems have one.
639 If you have a single-CPU system with an IO-APIC, you can say Y here
640 to use it. If you say Y here even though your machine doesn't have
641 an IO-APIC, then the kernel will still run with no slowdown at all.
643 config X86_LOCAL_APIC
645 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
649 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
651 config X86_VISWS_APIC
653 depends on X86_32 && X86_VISWS
656 bool "Machine Check Exception"
657 depends on !X86_VOYAGER
659 Machine Check Exception support allows the processor to notify the
660 kernel if it detects a problem (e.g. overheating, component failure).
661 The action the kernel takes depends on the severity of the problem,
662 ranging from a warning message on the console, to halting the machine.
663 Your processor must be a Pentium or newer to support this - check the
664 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
665 have a design flaw which leads to false MCE events - hence MCE is
666 disabled on all P5 processors, unless explicitly enabled with "mce"
667 as a boot argument. Similarly, if MCE is built in and creates a
668 problem on some new non-standard machine, you can boot with "nomce"
669 to disable it. MCE support simply ignores non-MCE processors like
670 the 386 and 486, so nearly everyone can say Y here.
674 prompt "Intel MCE features"
675 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
677 Additional support for intel specific MCE features such as
682 prompt "AMD MCE features"
683 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
685 Additional support for AMD specific MCE features such as
686 the DRAM Error Threshold.
688 config X86_MCE_NONFATAL
689 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
690 depends on X86_32 && X86_MCE
692 Enabling this feature starts a timer that triggers every 5 seconds which
693 will look at the machine check registers to see if anything happened.
694 Non-fatal problems automatically get corrected (but still logged).
695 Disable this if you don't want to see these messages.
696 Seeing the messages this option prints out may be indicative of dying
697 or out-of-spec (ie, overclocked) hardware.
698 This option only does something on certain CPUs.
699 (AMD Athlon/Duron and Intel Pentium 4)
701 config X86_MCE_P4THERMAL
702 bool "check for P4 thermal throttling interrupt."
703 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
705 Enabling this feature will cause a message to be printed when the P4
706 enters thermal throttling.
709 bool "Enable VM86 support" if EMBEDDED
713 This option is required by programs like DOSEMU to run 16-bit legacy
714 code on X86 processors. It also may be needed by software like
715 XFree86 to initialize some video cards via BIOS. Disabling this
716 option saves about 6k.
719 tristate "Toshiba Laptop support"
722 This adds a driver to safely access the System Management Mode of
723 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
724 not work on models with a Phoenix BIOS. The System Management Mode
725 is used to set the BIOS and power saving options on Toshiba portables.
727 For information on utilities to make use of this driver see the
728 Toshiba Linux utilities web site at:
729 <http://www.buzzard.org.uk/toshiba/>.
731 Say Y if you intend to run this kernel on a Toshiba portable.
735 tristate "Dell laptop support"
737 This adds a driver to safely access the System Management Mode
738 of the CPU on the Dell Inspiron 8000. The System Management Mode
739 is used to read cpu temperature and cooling fan status and to
740 control the fans on the I8K portables.
742 This driver has been tested only on the Inspiron 8000 but it may
743 also work with other Dell laptops. You can force loading on other
744 models by passing the parameter `force=1' to the module. Use at
747 For information on utilities to make use of this driver see the
748 I8K Linux utilities web site at:
749 <http://people.debian.org/~dz/i8k/>
751 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
754 config X86_REBOOTFIXUPS
755 bool "Enable X86 board specific fixups for reboot"
758 This enables chipset and/or board specific fixups to be done
759 in order to get reboot to work correctly. This is only needed on
760 some combinations of hardware and BIOS. The symptom, for which
761 this config is intended, is when reboot ends with a stalled/hung
764 Currently, the only fixup is for the Geode machines using
765 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
767 Say Y if you want to enable the fixup. Currently, it's safe to
768 enable this option even if you don't need it.
772 tristate "/dev/cpu/microcode - microcode support"
775 If you say Y here, you will be able to update the microcode on
776 certain Intel and AMD processors. The Intel support is for the
777 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
778 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
779 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
780 You will obviously need the actual microcode binary data itself
781 which is not shipped with the Linux kernel.
783 This option selects the general module only, you need to select
784 at least one vendor specific module as well.
786 To compile this driver as a module, choose M here: the
787 module will be called microcode.
789 config MICROCODE_INTEL
790 bool "Intel microcode patch loading support"
795 This options enables microcode patch loading support for Intel
798 For latest news and information on obtaining all the required
799 Intel ingredients for this driver, check:
800 <http://www.urbanmyth.org/microcode/>.
803 bool "AMD microcode patch loading support"
807 If you select this option, microcode patch loading support for AMD
808 processors will be enabled.
810 config MICROCODE_OLD_INTERFACE
815 tristate "/dev/cpu/*/msr - Model-specific register support"
817 This device gives privileged processes access to the x86
818 Model-Specific Registers (MSRs). It is a character device with
819 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
820 MSR accesses are directed to a specific CPU on multi-processor
824 tristate "/dev/cpu/*/cpuid - CPU information support"
826 This device gives processes access to the x86 CPUID instruction to
827 be executed on a specific processor. It is a character device
828 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
832 prompt "High Memory Support"
833 default HIGHMEM4G if !X86_NUMAQ
834 default HIGHMEM64G if X86_NUMAQ
839 depends on !X86_NUMAQ
841 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
842 However, the address space of 32-bit x86 processors is only 4
843 Gigabytes large. That means that, if you have a large amount of
844 physical memory, not all of it can be "permanently mapped" by the
845 kernel. The physical memory that's not permanently mapped is called
848 If you are compiling a kernel which will never run on a machine with
849 more than 1 Gigabyte total physical RAM, answer "off" here (default
850 choice and suitable for most users). This will result in a "3GB/1GB"
851 split: 3GB are mapped so that each process sees a 3GB virtual memory
852 space and the remaining part of the 4GB virtual memory space is used
853 by the kernel to permanently map as much physical memory as
856 If the machine has between 1 and 4 Gigabytes physical RAM, then
859 If more than 4 Gigabytes is used then answer "64GB" here. This
860 selection turns Intel PAE (Physical Address Extension) mode on.
861 PAE implements 3-level paging on IA32 processors. PAE is fully
862 supported by Linux, PAE mode is implemented on all recent Intel
863 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
864 then the kernel will not boot on CPUs that don't support PAE!
866 The actual amount of total physical memory will either be
867 auto detected or can be forced by using a kernel command line option
868 such as "mem=256M". (Try "man bootparam" or see the documentation of
869 your boot loader (lilo or loadlin) about how to pass options to the
870 kernel at boot time.)
872 If unsure, say "off".
876 depends on !X86_NUMAQ
878 Select this if you have a 32-bit processor and between 1 and 4
879 gigabytes of physical RAM.
883 depends on !M386 && !M486
886 Select this if you have a 32-bit processor and more than 4
887 gigabytes of physical RAM.
892 depends on EXPERIMENTAL
893 prompt "Memory split" if EMBEDDED
897 Select the desired split between kernel and user memory.
899 If the address range available to the kernel is less than the
900 physical memory installed, the remaining memory will be available
901 as "high memory". Accessing high memory is a little more costly
902 than low memory, as it needs to be mapped into the kernel first.
903 Note that increasing the kernel address space limits the range
904 available to user programs, making the address space there
905 tighter. Selecting anything other than the default 3G/1G split
906 will also likely make your kernel incompatible with binary-only
909 If you are not absolutely sure what you are doing, leave this
913 bool "3G/1G user/kernel split"
914 config VMSPLIT_3G_OPT
916 bool "3G/1G user/kernel split (for full 1G low memory)"
918 bool "2G/2G user/kernel split"
919 config VMSPLIT_2G_OPT
921 bool "2G/2G user/kernel split (for full 2G low memory)"
923 bool "1G/3G user/kernel split"
928 default 0xB0000000 if VMSPLIT_3G_OPT
929 default 0x80000000 if VMSPLIT_2G
930 default 0x78000000 if VMSPLIT_2G_OPT
931 default 0x40000000 if VMSPLIT_1G
937 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
940 bool "PAE (Physical Address Extension) Support"
941 depends on X86_32 && !HIGHMEM4G
943 PAE is required for NX support, and furthermore enables
944 larger swapspace support for non-overcommit purposes. It
945 has the cost of more pagetable lookup overhead, and also
946 consumes more pagetable space per process.
948 config ARCH_PHYS_ADDR_T_64BIT
949 def_bool X86_64 || X86_PAE
951 # Common NUMA Features
953 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
955 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
957 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
959 Enable NUMA (Non Uniform Memory Access) support.
960 The kernel will try to allocate memory used by a CPU on the
961 local memory controller of the CPU and add some more
962 NUMA awareness to the kernel.
964 For 32-bit this is currently highly experimental and should be only
965 used for kernel development. It might also cause boot failures.
966 For 64-bit this is recommended on all multiprocessor Opteron systems.
967 If the system is EM64T, you should say N unless your system is
970 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
971 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
975 prompt "Old style AMD Opteron NUMA detection"
976 depends on X86_64 && NUMA && PCI
978 Enable K8 NUMA node topology detection. You should say Y here if
979 you have a multi processor AMD K8 system. This uses an old
980 method to read the NUMA configuration directly from the builtin
981 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
982 instead, which also takes priority if both are compiled in.
984 config X86_64_ACPI_NUMA
986 prompt "ACPI NUMA detection"
987 depends on X86_64 && NUMA && ACPI && PCI
990 Enable ACPI SRAT based node topology detection.
992 # Some NUMA nodes have memory ranges that span
993 # other nodes. Even though a pfn is valid and
994 # between a node's start and end pfns, it may not
995 # reside on that node. See memmap_init_zone()
997 config NODES_SPAN_OTHER_NODES
999 depends on X86_64_ACPI_NUMA
1002 bool "NUMA emulation"
1003 depends on X86_64 && NUMA
1005 Enable NUMA emulation. A flat machine will be split
1006 into virtual nodes when booted with "numa=fake=N", where N is the
1007 number of nodes. This is only useful for debugging.
1010 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1012 default "9" if MAXSMP
1013 default "6" if X86_64
1014 default "4" if X86_NUMAQ
1016 depends on NEED_MULTIPLE_NODES
1018 Specify the maximum number of NUMA Nodes available on the target
1019 system. Increases memory reserved to accomodate various tables.
1021 config HAVE_ARCH_BOOTMEM_NODE
1023 depends on X86_32 && NUMA
1025 config ARCH_HAVE_MEMORY_PRESENT
1027 depends on X86_32 && DISCONTIGMEM
1029 config NEED_NODE_MEMMAP_SIZE
1031 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1033 config HAVE_ARCH_ALLOC_REMAP
1035 depends on X86_32 && NUMA
1037 config ARCH_FLATMEM_ENABLE
1039 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1041 config ARCH_DISCONTIGMEM_ENABLE
1043 depends on NUMA && X86_32
1045 config ARCH_DISCONTIGMEM_DEFAULT
1047 depends on NUMA && X86_32
1049 config ARCH_SPARSEMEM_DEFAULT
1053 config ARCH_SPARSEMEM_ENABLE
1055 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH
1056 select SPARSEMEM_STATIC if X86_32
1057 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1059 config ARCH_SELECT_MEMORY_MODEL
1061 depends on ARCH_SPARSEMEM_ENABLE
1063 config ARCH_MEMORY_PROBE
1065 depends on MEMORY_HOTPLUG
1070 bool "Allocate 3rd-level pagetables from highmem"
1071 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1073 The VM uses one page table entry for each page of physical memory.
1074 For systems with a lot of RAM, this can be wasteful of precious
1075 low memory. Setting this option will put user-space page table
1076 entries in high memory.
1078 config X86_CHECK_BIOS_CORRUPTION
1079 bool "Check for low memory corruption"
1081 Periodically check for memory corruption in low memory, which
1082 is suspected to be caused by BIOS. Even when enabled in the
1083 configuration, it is disabled at runtime. Enable it by
1084 setting "memory_corruption_check=1" on the kernel command
1085 line. By default it scans the low 64k of memory every 60
1086 seconds; see the memory_corruption_check_size and
1087 memory_corruption_check_period parameters in
1088 Documentation/kernel-parameters.txt to adjust this.
1090 When enabled with the default parameters, this option has
1091 almost no overhead, as it reserves a relatively small amount
1092 of memory and scans it infrequently. It both detects corruption
1093 and prevents it from affecting the running system.
1095 It is, however, intended as a diagnostic tool; if repeatable
1096 BIOS-originated corruption always affects the same memory,
1097 you can use memmap= to prevent the kernel from using that
1100 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1101 bool "Set the default setting of memory_corruption_check"
1102 depends on X86_CHECK_BIOS_CORRUPTION
1105 Set whether the default state of memory_corruption_check is
1108 config X86_RESERVE_LOW_64K
1109 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1112 Reserve the first 64K of physical RAM on BIOSes that are known
1113 to potentially corrupt that memory range. A numbers of BIOSes are
1114 known to utilize this area during suspend/resume, so it must not
1115 be used by the kernel.
1117 Set this to N if you are absolutely sure that you trust the BIOS
1118 to get all its memory reservations and usages right.
1120 If you have doubts about the BIOS (e.g. suspend/resume does not
1121 work or there's kernel crashes after certain hardware hotplug
1122 events) and it's not AMI or Phoenix, then you might want to enable
1123 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1124 corruption patterns.
1128 config MATH_EMULATION
1130 prompt "Math emulation" if X86_32
1132 Linux can emulate a math coprocessor (used for floating point
1133 operations) if you don't have one. 486DX and Pentium processors have
1134 a math coprocessor built in, 486SX and 386 do not, unless you added
1135 a 487DX or 387, respectively. (The messages during boot time can
1136 give you some hints here ["man dmesg"].) Everyone needs either a
1137 coprocessor or this emulation.
1139 If you don't have a math coprocessor, you need to say Y here; if you
1140 say Y here even though you have a coprocessor, the coprocessor will
1141 be used nevertheless. (This behavior can be changed with the kernel
1142 command line option "no387", which comes handy if your coprocessor
1143 is broken. Try "man bootparam" or see the documentation of your boot
1144 loader (lilo or loadlin) about how to pass options to the kernel at
1145 boot time.) This means that it is a good idea to say Y here if you
1146 intend to use this kernel on different machines.
1148 More information about the internals of the Linux math coprocessor
1149 emulation can be found in <file:arch/x86/math-emu/README>.
1151 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1152 kernel, it won't hurt.
1155 bool "MTRR (Memory Type Range Register) support"
1157 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1158 the Memory Type Range Registers (MTRRs) may be used to control
1159 processor access to memory ranges. This is most useful if you have
1160 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1161 allows bus write transfers to be combined into a larger transfer
1162 before bursting over the PCI/AGP bus. This can increase performance
1163 of image write operations 2.5 times or more. Saying Y here creates a
1164 /proc/mtrr file which may be used to manipulate your processor's
1165 MTRRs. Typically the X server should use this.
1167 This code has a reasonably generic interface so that similar
1168 control registers on other processors can be easily supported
1171 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1172 Registers (ARRs) which provide a similar functionality to MTRRs. For
1173 these, the ARRs are used to emulate the MTRRs.
1174 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1175 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1176 write-combining. All of these processors are supported by this code
1177 and it makes sense to say Y here if you have one of them.
1179 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1180 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1181 can lead to all sorts of problems, so it's good to say Y here.
1183 You can safely say Y even if your machine doesn't have MTRRs, you'll
1184 just add about 9 KB to your kernel.
1186 See <file:Documentation/x86/mtrr.txt> for more information.
1188 config MTRR_SANITIZER
1190 prompt "MTRR cleanup support"
1193 Convert MTRR layout from continuous to discrete, so X drivers can
1194 add writeback entries.
1196 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1197 The largest mtrr entry size for a continous block can be set with
1202 config MTRR_SANITIZER_ENABLE_DEFAULT
1203 int "MTRR cleanup enable value (0-1)"
1206 depends on MTRR_SANITIZER
1208 Enable mtrr cleanup default value
1210 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1211 int "MTRR cleanup spare reg num (0-7)"
1214 depends on MTRR_SANITIZER
1216 mtrr cleanup spare entries default, it can be changed via
1217 mtrr_spare_reg_nr=N on the kernel command line.
1221 prompt "x86 PAT support"
1224 Use PAT attributes to setup page level cache control.
1226 PATs are the modern equivalents of MTRRs and are much more
1227 flexible than MTRRs.
1229 Say N here if you see bootup problems (boot crash, boot hang,
1230 spontaneous reboots) or a non-working video driver.
1235 bool "EFI runtime service support"
1238 This enables the kernel to use EFI runtime services that are
1239 available (such as the EFI variable services).
1241 This option is only useful on systems that have EFI firmware.
1242 In addition, you should use the latest ELILO loader available
1243 at <http://elilo.sourceforge.net> in order to take advantage
1244 of EFI runtime services. However, even with this option, the
1245 resultant kernel should continue to boot on existing non-EFI
1250 prompt "Enable seccomp to safely compute untrusted bytecode"
1252 This kernel feature is useful for number crunching applications
1253 that may need to compute untrusted bytecode during their
1254 execution. By using pipes or other transports made available to
1255 the process as file descriptors supporting the read/write
1256 syscalls, it's possible to isolate those applications in
1257 their own address space using seccomp. Once seccomp is
1258 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1259 and the task is only allowed to execute a few safe syscalls
1260 defined by each seccomp mode.
1262 If unsure, say Y. Only embedded should say N here.
1264 config CC_STACKPROTECTOR
1265 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1266 depends on X86_64 && EXPERIMENTAL && BROKEN
1268 This option turns on the -fstack-protector GCC feature. This
1269 feature puts, at the beginning of critical functions, a canary
1270 value on the stack just before the return address, and validates
1271 the value just before actually returning. Stack based buffer
1272 overflows (that need to overwrite this return address) now also
1273 overwrite the canary, which gets detected and the attack is then
1274 neutralized via a kernel panic.
1276 This feature requires gcc version 4.2 or above, or a distribution
1277 gcc with the feature backported. Older versions are automatically
1278 detected and for those versions, this configuration option is ignored.
1280 config CC_STACKPROTECTOR_ALL
1281 bool "Use stack-protector for all functions"
1282 depends on CC_STACKPROTECTOR
1284 Normally, GCC only inserts the canary value protection for
1285 functions that use large-ish on-stack buffers. By enabling
1286 this option, GCC will be asked to do this for ALL functions.
1288 source kernel/Kconfig.hz
1291 bool "kexec system call"
1292 depends on X86_BIOS_REBOOT
1294 kexec is a system call that implements the ability to shutdown your
1295 current kernel, and to start another kernel. It is like a reboot
1296 but it is independent of the system firmware. And like a reboot
1297 you can start any kernel with it, not just Linux.
1299 The name comes from the similarity to the exec system call.
1301 It is an ongoing process to be certain the hardware in a machine
1302 is properly shutdown, so do not be surprised if this code does not
1303 initially work for you. It may help to enable device hotplugging
1304 support. As of this writing the exact hardware interface is
1305 strongly in flux, so no good recommendation can be made.
1308 bool "kernel crash dumps"
1309 depends on X86_64 || (X86_32 && HIGHMEM)
1311 Generate crash dump after being started by kexec.
1312 This should be normally only set in special crash dump kernels
1313 which are loaded in the main kernel with kexec-tools into
1314 a specially reserved region and then later executed after
1315 a crash by kdump/kexec. The crash dump kernel must be compiled
1316 to a memory address not used by the main kernel or BIOS using
1317 PHYSICAL_START, or it must be built as a relocatable image
1318 (CONFIG_RELOCATABLE=y).
1319 For more details see Documentation/kdump/kdump.txt
1322 bool "kexec jump (EXPERIMENTAL)"
1323 depends on EXPERIMENTAL
1324 depends on KEXEC && HIBERNATION && X86_32
1326 Jump between original kernel and kexeced kernel and invoke
1327 code in physical address mode via KEXEC
1329 config PHYSICAL_START
1330 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1331 default "0x1000000" if X86_NUMAQ
1332 default "0x200000" if X86_64
1335 This gives the physical address where the kernel is loaded.
1337 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1338 bzImage will decompress itself to above physical address and
1339 run from there. Otherwise, bzImage will run from the address where
1340 it has been loaded by the boot loader and will ignore above physical
1343 In normal kdump cases one does not have to set/change this option
1344 as now bzImage can be compiled as a completely relocatable image
1345 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1346 address. This option is mainly useful for the folks who don't want
1347 to use a bzImage for capturing the crash dump and want to use a
1348 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1349 to be specifically compiled to run from a specific memory area
1350 (normally a reserved region) and this option comes handy.
1352 So if you are using bzImage for capturing the crash dump, leave
1353 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1354 Otherwise if you plan to use vmlinux for capturing the crash dump
1355 change this value to start of the reserved region (Typically 16MB
1356 0x1000000). In other words, it can be set based on the "X" value as
1357 specified in the "crashkernel=YM@XM" command line boot parameter
1358 passed to the panic-ed kernel. Typically this parameter is set as
1359 crashkernel=64M@16M. Please take a look at
1360 Documentation/kdump/kdump.txt for more details about crash dumps.
1362 Usage of bzImage for capturing the crash dump is recommended as
1363 one does not have to build two kernels. Same kernel can be used
1364 as production kernel and capture kernel. Above option should have
1365 gone away after relocatable bzImage support is introduced. But it
1366 is present because there are users out there who continue to use
1367 vmlinux for dump capture. This option should go away down the
1370 Don't change this unless you know what you are doing.
1373 bool "Build a relocatable kernel (EXPERIMENTAL)"
1374 depends on EXPERIMENTAL
1376 This builds a kernel image that retains relocation information
1377 so it can be loaded someplace besides the default 1MB.
1378 The relocations tend to make the kernel binary about 10% larger,
1379 but are discarded at runtime.
1381 One use is for the kexec on panic case where the recovery kernel
1382 must live at a different physical address than the primary
1385 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1386 it has been loaded at and the compile time physical address
1387 (CONFIG_PHYSICAL_START) is ignored.
1389 config PHYSICAL_ALIGN
1391 prompt "Alignment value to which kernel should be aligned" if X86_32
1392 default "0x100000" if X86_32
1393 default "0x200000" if X86_64
1394 range 0x2000 0x400000
1396 This value puts the alignment restrictions on physical address
1397 where kernel is loaded and run from. Kernel is compiled for an
1398 address which meets above alignment restriction.
1400 If bootloader loads the kernel at a non-aligned address and
1401 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1402 address aligned to above value and run from there.
1404 If bootloader loads the kernel at a non-aligned address and
1405 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1406 load address and decompress itself to the address it has been
1407 compiled for and run from there. The address for which kernel is
1408 compiled already meets above alignment restrictions. Hence the
1409 end result is that kernel runs from a physical address meeting
1410 above alignment restrictions.
1412 Don't change this unless you know what you are doing.
1415 bool "Support for hot-pluggable CPUs"
1416 depends on SMP && HOTPLUG && !X86_VOYAGER
1418 Say Y here to allow turning CPUs off and on. CPUs can be
1419 controlled through /sys/devices/system/cpu.
1420 ( Note: power management support will enable this option
1421 automatically on SMP systems. )
1422 Say N if you want to disable CPU hotplug.
1426 prompt "Compat VDSO support"
1427 depends on X86_32 || IA32_EMULATION
1429 Map the 32-bit VDSO to the predictable old-style address too.
1431 Say N here if you are running a sufficiently recent glibc
1432 version (2.3.3 or later), to remove the high-mapped
1433 VDSO mapping and to exclusively use the randomized VDSO.
1438 bool "Built-in kernel command line"
1441 Allow for specifying boot arguments to the kernel at
1442 build time. On some systems (e.g. embedded ones), it is
1443 necessary or convenient to provide some or all of the
1444 kernel boot arguments with the kernel itself (that is,
1445 to not rely on the boot loader to provide them.)
1447 To compile command line arguments into the kernel,
1448 set this option to 'Y', then fill in the
1449 the boot arguments in CONFIG_CMDLINE.
1451 Systems with fully functional boot loaders (i.e. non-embedded)
1452 should leave this option set to 'N'.
1455 string "Built-in kernel command string"
1456 depends on CMDLINE_BOOL
1459 Enter arguments here that should be compiled into the kernel
1460 image and used at boot time. If the boot loader provides a
1461 command line at boot time, it is appended to this string to
1462 form the full kernel command line, when the system boots.
1464 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1465 change this behavior.
1467 In most cases, the command line (whether built-in or provided
1468 by the boot loader) should specify the device for the root
1471 config CMDLINE_OVERRIDE
1472 bool "Built-in command line overrides boot loader arguments"
1474 depends on CMDLINE_BOOL
1476 Set this option to 'Y' to have the kernel ignore the boot loader
1477 command line, and use ONLY the built-in command line.
1479 This is used to work around broken boot loaders. This should
1480 be set to 'N' under normal conditions.
1484 config ARCH_ENABLE_MEMORY_HOTPLUG
1486 depends on X86_64 || (X86_32 && HIGHMEM)
1488 config HAVE_ARCH_EARLY_PFN_TO_NID
1492 menu "Power management and ACPI options"
1493 depends on !X86_VOYAGER
1495 config ARCH_HIBERNATION_HEADER
1497 depends on X86_64 && HIBERNATION
1499 source "kernel/power/Kconfig"
1501 source "drivers/acpi/Kconfig"
1506 depends on APM || APM_MODULE
1509 tristate "APM (Advanced Power Management) BIOS support"
1510 depends on X86_32 && PM_SLEEP
1512 APM is a BIOS specification for saving power using several different
1513 techniques. This is mostly useful for battery powered laptops with
1514 APM compliant BIOSes. If you say Y here, the system time will be
1515 reset after a RESUME operation, the /proc/apm device will provide
1516 battery status information, and user-space programs will receive
1517 notification of APM "events" (e.g. battery status change).
1519 If you select "Y" here, you can disable actual use of the APM
1520 BIOS by passing the "apm=off" option to the kernel at boot time.
1522 Note that the APM support is almost completely disabled for
1523 machines with more than one CPU.
1525 In order to use APM, you will need supporting software. For location
1526 and more information, read <file:Documentation/power/pm.txt> and the
1527 Battery Powered Linux mini-HOWTO, available from
1528 <http://www.tldp.org/docs.html#howto>.
1530 This driver does not spin down disk drives (see the hdparm(8)
1531 manpage ("man 8 hdparm") for that), and it doesn't turn off
1532 VESA-compliant "green" monitors.
1534 This driver does not support the TI 4000M TravelMate and the ACER
1535 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1536 desktop machines also don't have compliant BIOSes, and this driver
1537 may cause those machines to panic during the boot phase.
1539 Generally, if you don't have a battery in your machine, there isn't
1540 much point in using this driver and you should say N. If you get
1541 random kernel OOPSes or reboots that don't seem to be related to
1542 anything, try disabling/enabling this option (or disabling/enabling
1545 Some other things you should try when experiencing seemingly random,
1548 1) make sure that you have enough swap space and that it is
1550 2) pass the "no-hlt" option to the kernel
1551 3) switch on floating point emulation in the kernel and pass
1552 the "no387" option to the kernel
1553 4) pass the "floppy=nodma" option to the kernel
1554 5) pass the "mem=4M" option to the kernel (thereby disabling
1555 all but the first 4 MB of RAM)
1556 6) make sure that the CPU is not over clocked.
1557 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1558 8) disable the cache from your BIOS settings
1559 9) install a fan for the video card or exchange video RAM
1560 10) install a better fan for the CPU
1561 11) exchange RAM chips
1562 12) exchange the motherboard.
1564 To compile this driver as a module, choose M here: the
1565 module will be called apm.
1569 config APM_IGNORE_USER_SUSPEND
1570 bool "Ignore USER SUSPEND"
1572 This option will ignore USER SUSPEND requests. On machines with a
1573 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1574 series notebooks, it is necessary to say Y because of a BIOS bug.
1576 config APM_DO_ENABLE
1577 bool "Enable PM at boot time"
1579 Enable APM features at boot time. From page 36 of the APM BIOS
1580 specification: "When disabled, the APM BIOS does not automatically
1581 power manage devices, enter the Standby State, enter the Suspend
1582 State, or take power saving steps in response to CPU Idle calls."
1583 This driver will make CPU Idle calls when Linux is idle (unless this
1584 feature is turned off -- see "Do CPU IDLE calls", below). This
1585 should always save battery power, but more complicated APM features
1586 will be dependent on your BIOS implementation. You may need to turn
1587 this option off if your computer hangs at boot time when using APM
1588 support, or if it beeps continuously instead of suspending. Turn
1589 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1590 T400CDT. This is off by default since most machines do fine without
1594 bool "Make CPU Idle calls when idle"
1596 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1597 On some machines, this can activate improved power savings, such as
1598 a slowed CPU clock rate, when the machine is idle. These idle calls
1599 are made after the idle loop has run for some length of time (e.g.,
1600 333 mS). On some machines, this will cause a hang at boot time or
1601 whenever the CPU becomes idle. (On machines with more than one CPU,
1602 this option does nothing.)
1604 config APM_DISPLAY_BLANK
1605 bool "Enable console blanking using APM"
1607 Enable console blanking using the APM. Some laptops can use this to
1608 turn off the LCD backlight when the screen blanker of the Linux
1609 virtual console blanks the screen. Note that this is only used by
1610 the virtual console screen blanker, and won't turn off the backlight
1611 when using the X Window system. This also doesn't have anything to
1612 do with your VESA-compliant power-saving monitor. Further, this
1613 option doesn't work for all laptops -- it might not turn off your
1614 backlight at all, or it might print a lot of errors to the console,
1615 especially if you are using gpm.
1617 config APM_ALLOW_INTS
1618 bool "Allow interrupts during APM BIOS calls"
1620 Normally we disable external interrupts while we are making calls to
1621 the APM BIOS as a measure to lessen the effects of a badly behaving
1622 BIOS implementation. The BIOS should reenable interrupts if it
1623 needs to. Unfortunately, some BIOSes do not -- especially those in
1624 many of the newer IBM Thinkpads. If you experience hangs when you
1625 suspend, try setting this to Y. Otherwise, say N.
1627 config APM_REAL_MODE_POWER_OFF
1628 bool "Use real mode APM BIOS call to power off"
1630 Use real mode APM BIOS calls to switch off the computer. This is
1631 a work-around for a number of buggy BIOSes. Switch this option on if
1632 your computer crashes instead of powering off properly.
1636 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1638 source "drivers/cpuidle/Kconfig"
1640 source "drivers/idle/Kconfig"
1645 menu "Bus options (PCI etc.)"
1650 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1652 Find out whether you have a PCI motherboard. PCI is the name of a
1653 bus system, i.e. the way the CPU talks to the other stuff inside
1654 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1655 VESA. If you have PCI, say Y, otherwise N.
1658 prompt "PCI access mode"
1659 depends on X86_32 && PCI
1662 On PCI systems, the BIOS can be used to detect the PCI devices and
1663 determine their configuration. However, some old PCI motherboards
1664 have BIOS bugs and may crash if this is done. Also, some embedded
1665 PCI-based systems don't have any BIOS at all. Linux can also try to
1666 detect the PCI hardware directly without using the BIOS.
1668 With this option, you can specify how Linux should detect the
1669 PCI devices. If you choose "BIOS", the BIOS will be used,
1670 if you choose "Direct", the BIOS won't be used, and if you
1671 choose "MMConfig", then PCI Express MMCONFIG will be used.
1672 If you choose "Any", the kernel will try MMCONFIG, then the
1673 direct access method and falls back to the BIOS if that doesn't
1674 work. If unsure, go with the default, which is "Any".
1679 config PCI_GOMMCONFIG
1696 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1698 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1701 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1705 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1709 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1716 bool "Support mmconfig PCI config space access"
1717 depends on X86_64 && PCI && ACPI
1720 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1721 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1723 DMA remapping (DMAR) devices support enables independent address
1724 translations for Direct Memory Access (DMA) from devices.
1725 These DMA remapping devices are reported via ACPI tables
1726 and include PCI device scope covered by these DMA
1731 prompt "Support for Graphics workaround"
1734 Current Graphics drivers tend to use physical address
1735 for DMA and avoid using DMA APIs. Setting this config
1736 option permits the IOMMU driver to set a unity map for
1737 all the OS-visible memory. Hence the driver can continue
1738 to use physical addresses for DMA.
1740 config DMAR_FLOPPY_WA
1744 Floppy disk drivers are know to bypass DMA API calls
1745 thereby failing to work when IOMMU is enabled. This
1746 workaround will setup a 1:1 mapping for the first
1747 16M to make floppy (an ISA device) work.
1750 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1751 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1753 Supports Interrupt remapping for IO-APIC and MSI devices.
1754 To use x2apic mode in the CPU's which support x2APIC enhancements or
1755 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1757 source "drivers/pci/pcie/Kconfig"
1759 source "drivers/pci/Kconfig"
1761 # x86_64 have no ISA slots, but do have ISA-style DMA.
1769 depends on !X86_VOYAGER
1771 Find out whether you have ISA slots on your motherboard. ISA is the
1772 name of a bus system, i.e. the way the CPU talks to the other stuff
1773 inside your box. Other bus systems are PCI, EISA, MicroChannel
1774 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1775 newer boards don't support it. If you have ISA, say Y, otherwise N.
1781 The Extended Industry Standard Architecture (EISA) bus was
1782 developed as an open alternative to the IBM MicroChannel bus.
1784 The EISA bus provided some of the features of the IBM MicroChannel
1785 bus while maintaining backward compatibility with cards made for
1786 the older ISA bus. The EISA bus saw limited use between 1988 and
1787 1995 when it was made obsolete by the PCI bus.
1789 Say Y here if you are building a kernel for an EISA-based machine.
1793 source "drivers/eisa/Kconfig"
1796 bool "MCA support" if !X86_VOYAGER
1797 default y if X86_VOYAGER
1799 MicroChannel Architecture is found in some IBM PS/2 machines and
1800 laptops. It is a bus system similar to PCI or ISA. See
1801 <file:Documentation/mca.txt> (and especially the web page given
1802 there) before attempting to build an MCA bus kernel.
1804 source "drivers/mca/Kconfig"
1807 tristate "NatSemi SCx200 support"
1808 depends on !X86_VOYAGER
1810 This provides basic support for National Semiconductor's
1811 (now AMD's) Geode processors. The driver probes for the
1812 PCI-IDs of several on-chip devices, so its a good dependency
1813 for other scx200_* drivers.
1815 If compiled as a module, the driver is named scx200.
1817 config SCx200HR_TIMER
1818 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1819 depends on SCx200 && GENERIC_TIME
1822 This driver provides a clocksource built upon the on-chip
1823 27MHz high-resolution timer. Its also a workaround for
1824 NSC Geode SC-1100's buggy TSC, which loses time when the
1825 processor goes idle (as is done by the scheduler). The
1826 other workaround is idle=poll boot option.
1828 config GEODE_MFGPT_TIMER
1830 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1831 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1833 This driver provides a clock event source based on the MFGPT
1834 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1835 MFGPTs have a better resolution and max interval than the
1836 generic PIT, and are suitable for use as high-res timers.
1839 bool "One Laptop Per Child support"
1842 Add support for detecting the unique features of the OLPC
1849 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1851 source "drivers/pcmcia/Kconfig"
1853 source "drivers/pci/hotplug/Kconfig"
1858 menu "Executable file formats / Emulations"
1860 source "fs/Kconfig.binfmt"
1862 config IA32_EMULATION
1863 bool "IA32 Emulation"
1865 select COMPAT_BINFMT_ELF
1867 Include code to run 32-bit programs under a 64-bit kernel. You should
1868 likely turn this on, unless you're 100% sure that you don't have any
1869 32-bit programs left.
1872 tristate "IA32 a.out support"
1873 depends on IA32_EMULATION
1875 Support old a.out binaries in the 32bit emulation.
1879 depends on IA32_EMULATION
1881 config COMPAT_FOR_U64_ALIGNMENT
1885 config SYSVIPC_COMPAT
1887 depends on COMPAT && SYSVIPC
1892 config HAVE_ATOMIC_IOMAP
1896 source "net/Kconfig"
1898 source "drivers/Kconfig"
1900 source "drivers/firmware/Kconfig"
1904 source "arch/x86/Kconfig.debug"
1906 source "security/Kconfig"
1908 source "crypto/Kconfig"
1910 source "arch/x86/kvm/Kconfig"
1912 source "lib/Kconfig"
projects / linux-2.6 / blob