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)
170 select USE_GENERIC_SMP_HELPERS
175 depends on X86_32 && SMP
179 depends on X86_64 && SMP
184 depends on (X86_32 && !X86_VOYAGER) || X86_64
187 config X86_BIOS_REBOOT
189 depends on !X86_VOYAGER
192 config X86_TRAMPOLINE
194 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
199 source "init/Kconfig"
200 source "kernel/Kconfig.freezer"
202 menu "Processor type and features"
204 source "kernel/time/Kconfig"
207 bool "Symmetric multi-processing support"
209 This enables support for systems with more than one CPU. If you have
210 a system with only one CPU, like most personal computers, say N. If
211 you have a system with more than one CPU, say Y.
213 If you say N here, the kernel will run on single and multiprocessor
214 machines, but will use only one CPU of a multiprocessor machine. If
215 you say Y here, the kernel will run on many, but not all,
216 singleprocessor machines. On a singleprocessor machine, the kernel
217 will run faster if you say N here.
219 Note that if you say Y here and choose architecture "586" or
220 "Pentium" under "Processor family", the kernel will not work on 486
221 architectures. Similarly, multiprocessor kernels for the "PPro"
222 architecture may not work on all Pentium based boards.
224 People using multiprocessor machines who say Y here should also say
225 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
226 Management" code will be disabled if you say Y here.
228 See also <file:Documentation/i386/IO-APIC.txt>,
229 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
230 <http://www.tldp.org/docs.html#howto>.
232 If you don't know what to do here, say N.
234 config X86_HAS_BOOT_CPU_ID
236 depends on X86_VOYAGER
238 config X86_FIND_SMP_CONFIG
240 depends on X86_MPPARSE || X86_VOYAGER
245 bool "Enable MPS table"
246 depends on X86_LOCAL_APIC
248 For old smp systems that do not have proper acpi support. Newer systems
249 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
255 depends on X86_LOCAL_APIC
259 prompt "Subarchitecture Type"
265 Choose this option if your computer is a standard PC or compatible.
271 Select this for an AMD Elan processor.
273 Do not use this option for K6/Athlon/Opteron processors!
275 If unsure, choose "PC-compatible" instead.
279 depends on X86_32 && (SMP || BROKEN) && !PCI
281 Voyager is an MCA-based 32-way capable SMP architecture proprietary
282 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
286 If you do not specifically know you have a Voyager based machine,
287 say N here, otherwise the kernel you build will not be bootable.
289 config X86_GENERICARCH
290 bool "Generic architecture"
293 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
294 subarchitectures. It is intended for a generic binary kernel.
295 if you select them all, kernel will probe it one by one. and will
301 bool "NUMAQ (IBM/Sequent)"
302 depends on SMP && X86_32 && PCI && X86_MPPARSE
305 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
306 NUMA multiquad box. This changes the way that processors are
307 bootstrapped, and uses Clustered Logical APIC addressing mode instead
308 of Flat Logical. You will need a new lynxer.elf file to flash your
309 firmware with - send email to <Martin.Bligh@us.ibm.com>.
312 bool "Summit/EXA (IBM x440)"
313 depends on X86_32 && SMP
315 This option is needed for IBM systems that use the Summit/EXA chipset.
316 In particular, it is needed for the x440.
319 bool "Support for Unisys ES7000 IA32 series"
320 depends on X86_32 && SMP
322 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
323 supposed to run on an IA32-based Unisys ES7000 system.
326 bool "Support for big SMP systems with more than 8 CPUs"
327 depends on X86_32 && SMP
329 This option is needed for the systems that have more than 8 CPUs
330 and if the system is not of any sub-arch type above.
335 bool "Support for ScaleMP vSMP"
337 depends on X86_64 && PCI
339 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
340 supposed to run on these EM64T-based machines. Only choose this option
341 if you have one of these machines.
346 bool "SGI 320/540 (Visual Workstation)"
347 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
349 The SGI Visual Workstation series is an IA32-based workstation
350 based on SGI systems chips with some legacy PC hardware attached.
352 Say Y here to create a kernel to run on the SGI 320 or 540.
354 A kernel compiled for the Visual Workstation will run on general
355 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
358 bool "RDC R-321x SoC"
361 select X86_REBOOTFIXUPS
363 This option is needed for RDC R-321x system-on-chip, also known
365 If you don't have one of these chips, you should say N here.
367 config SCHED_NO_NO_OMIT_FRAME_POINTER
369 prompt "Single-depth WCHAN output"
372 Calculate simpler /proc/<PID>/wchan values. If this option
373 is disabled then wchan values will recurse back to the
374 caller function. This provides more accurate wchan values,
375 at the expense of slightly more scheduling overhead.
377 If in doubt, say "Y".
379 menuconfig PARAVIRT_GUEST
380 bool "Paravirtualized guest support"
382 Say Y here to get to see options related to running Linux under
383 various hypervisors. This option alone does not add any kernel code.
385 If you say N, all options in this submenu will be skipped and disabled.
389 source "arch/x86/xen/Kconfig"
392 bool "VMI Guest support"
395 depends on !X86_VOYAGER
397 VMI provides a paravirtualized interface to the VMware ESX server
398 (it could be used by other hypervisors in theory too, but is not
399 at the moment), by linking the kernel to a GPL-ed ROM module
400 provided by the hypervisor.
403 bool "KVM paravirtualized clock"
405 select PARAVIRT_CLOCK
406 depends on !X86_VOYAGER
408 Turning on this option will allow you to run a paravirtualized clock
409 when running over the KVM hypervisor. Instead of relying on a PIT
410 (or probably other) emulation by the underlying device model, the host
411 provides the guest with timing infrastructure such as time of day, and
415 bool "KVM Guest support"
417 depends on !X86_VOYAGER
419 This option enables various optimizations for running under the KVM
422 source "arch/x86/lguest/Kconfig"
425 bool "Enable paravirtualization code"
426 depends on !X86_VOYAGER
428 This changes the kernel so it can modify itself when it is run
429 under a hypervisor, potentially improving performance significantly
430 over full virtualization. However, when run without a hypervisor
431 the kernel is theoretically slower and slightly larger.
433 config PARAVIRT_CLOCK
439 config PARAVIRT_DEBUG
440 bool "paravirt-ops debugging"
441 depends on PARAVIRT && DEBUG_KERNEL
443 Enable to debug paravirt_ops internals. Specifically, BUG if
444 a paravirt_op is missing when it is called.
449 This option adds a kernel parameter 'memtest', which allows memtest
451 memtest=0, mean disabled; -- default
452 memtest=1, mean do 1 test pattern;
454 memtest=4, mean do 4 test patterns.
455 If you are unsure how to answer this question, answer N.
457 config X86_SUMMIT_NUMA
459 depends on X86_32 && NUMA && X86_GENERICARCH
461 config X86_CYCLONE_TIMER
463 depends on X86_GENERICARCH
465 config ES7000_CLUSTERED_APIC
467 depends on SMP && X86_ES7000 && MPENTIUMIII
469 source "arch/x86/Kconfig.cpu"
473 prompt "HPET Timer Support" if X86_32
475 Use the IA-PC HPET (High Precision Event Timer) to manage
476 time in preference to the PIT and RTC, if a HPET is
478 HPET is the next generation timer replacing legacy 8254s.
479 The HPET provides a stable time base on SMP
480 systems, unlike the TSC, but it is more expensive to access,
481 as it is off-chip. You can find the HPET spec at
482 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
484 You can safely choose Y here. However, HPET will only be
485 activated if the platform and the BIOS support this feature.
486 Otherwise the 8254 will be used for timing services.
488 Choose N to continue using the legacy 8254 timer.
490 config HPET_EMULATE_RTC
492 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
494 # Mark as embedded because too many people got it wrong.
495 # The code disables itself when not needed.
498 bool "Enable DMI scanning" if EMBEDDED
500 Enabled scanning of DMI to identify machine quirks. Say Y
501 here unless you have verified that your setup is not
502 affected by entries in the DMI blacklist. Required by PNP
506 bool "GART IOMMU support" if EMBEDDED
510 depends on X86_64 && PCI
512 Support for full DMA access of devices with 32bit memory access only
513 on systems with more than 3GB. This is usually needed for USB,
514 sound, many IDE/SATA chipsets and some other devices.
515 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
516 based hardware IOMMU and a software bounce buffer based IOMMU used
517 on Intel systems and as fallback.
518 The code is only active when needed (enough memory and limited
519 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
523 bool "IBM Calgary IOMMU support"
525 depends on X86_64 && PCI && EXPERIMENTAL
527 Support for hardware IOMMUs in IBM's xSeries x366 and x460
528 systems. Needed to run systems with more than 3GB of memory
529 properly with 32-bit PCI devices that do not support DAC
530 (Double Address Cycle). Calgary also supports bus level
531 isolation, where all DMAs pass through the IOMMU. This
532 prevents them from going anywhere except their intended
533 destination. This catches hard-to-find kernel bugs and
534 mis-behaving drivers and devices that do not use the DMA-API
535 properly to set up their DMA buffers. The IOMMU can be
536 turned off at boot time with the iommu=off parameter.
537 Normally the kernel will make the right choice by itself.
540 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
542 prompt "Should Calgary be enabled by default?"
543 depends on CALGARY_IOMMU
545 Should Calgary be enabled by default? if you choose 'y', Calgary
546 will be used (if it exists). If you choose 'n', Calgary will not be
547 used even if it exists. If you choose 'n' and would like to use
548 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
552 bool "AMD IOMMU support"
555 depends on X86_64 && PCI && ACPI
557 With this option you can enable support for AMD IOMMU hardware in
558 your system. An IOMMU is a hardware component which provides
559 remapping of DMA memory accesses from devices. With an AMD IOMMU you
560 can isolate the the DMA memory of different devices and protect the
561 system from misbehaving device drivers or hardware.
563 You can find out if your system has an AMD IOMMU if you look into
564 your BIOS for an option to enable it or if you have an IVRS ACPI
567 # need this always selected by IOMMU for the VIA workaround
571 Support for software bounce buffers used on x86-64 systems
572 which don't have a hardware IOMMU (e.g. the current generation
573 of Intel's x86-64 CPUs). Using this PCI devices which can only
574 access 32-bits of memory can be used on systems with more than
575 3 GB of memory. If unsure, say Y.
578 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
581 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
582 depends on X86_64 && SMP && BROKEN
585 Configure maximum number of CPUS and NUMA Nodes for this architecture.
589 int "Maximum number of CPUs (2-512)" if !MAXSMP
592 default "4096" if MAXSMP
593 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
596 This allows you to specify the maximum number of CPUs which this
597 kernel will support. The maximum supported value is 512 and the
598 minimum value which makes sense is 2.
600 This is purely to save memory - each supported CPU adds
601 approximately eight kilobytes to the kernel image.
604 bool "SMT (Hyperthreading) scheduler support"
607 SMT scheduler support improves the CPU scheduler's decision making
608 when dealing with Intel Pentium 4 chips with HyperThreading at a
609 cost of slightly increased overhead in some places. If unsure say
614 prompt "Multi-core scheduler support"
617 Multi-core scheduler support improves the CPU scheduler's decision
618 making when dealing with multi-core CPU chips at a cost of slightly
619 increased overhead in some places. If unsure say N here.
621 source "kernel/Kconfig.preempt"
624 bool "Local APIC support on uniprocessors"
625 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
627 A local APIC (Advanced Programmable Interrupt Controller) is an
628 integrated interrupt controller in the CPU. If you have a single-CPU
629 system which has a processor with a local APIC, you can say Y here to
630 enable and use it. If you say Y here even though your machine doesn't
631 have a local APIC, then the kernel will still run with no slowdown at
632 all. The local APIC supports CPU-generated self-interrupts (timer,
633 performance counters), and the NMI watchdog which detects hard
637 bool "IO-APIC support on uniprocessors"
638 depends on X86_UP_APIC
640 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
641 SMP-capable replacement for PC-style interrupt controllers. Most
642 SMP systems and many recent uniprocessor systems have one.
644 If you have a single-CPU system with an IO-APIC, you can say Y here
645 to use it. If you say Y here even though your machine doesn't have
646 an IO-APIC, then the kernel will still run with no slowdown at all.
648 config X86_LOCAL_APIC
650 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
654 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
656 config X86_VISWS_APIC
658 depends on X86_32 && X86_VISWS
661 bool "Machine Check Exception"
662 depends on !X86_VOYAGER
664 Machine Check Exception support allows the processor to notify the
665 kernel if it detects a problem (e.g. overheating, component failure).
666 The action the kernel takes depends on the severity of the problem,
667 ranging from a warning message on the console, to halting the machine.
668 Your processor must be a Pentium or newer to support this - check the
669 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
670 have a design flaw which leads to false MCE events - hence MCE is
671 disabled on all P5 processors, unless explicitly enabled with "mce"
672 as a boot argument. Similarly, if MCE is built in and creates a
673 problem on some new non-standard machine, you can boot with "nomce"
674 to disable it. MCE support simply ignores non-MCE processors like
675 the 386 and 486, so nearly everyone can say Y here.
679 prompt "Intel MCE features"
680 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
682 Additional support for intel specific MCE features such as
687 prompt "AMD MCE features"
688 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
690 Additional support for AMD specific MCE features such as
691 the DRAM Error Threshold.
693 config X86_MCE_NONFATAL
694 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
695 depends on X86_32 && X86_MCE
697 Enabling this feature starts a timer that triggers every 5 seconds which
698 will look at the machine check registers to see if anything happened.
699 Non-fatal problems automatically get corrected (but still logged).
700 Disable this if you don't want to see these messages.
701 Seeing the messages this option prints out may be indicative of dying
702 or out-of-spec (ie, overclocked) hardware.
703 This option only does something on certain CPUs.
704 (AMD Athlon/Duron and Intel Pentium 4)
706 config X86_MCE_P4THERMAL
707 bool "check for P4 thermal throttling interrupt."
708 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
710 Enabling this feature will cause a message to be printed when the P4
711 enters thermal throttling.
714 bool "Enable VM86 support" if EMBEDDED
718 This option is required by programs like DOSEMU to run 16-bit legacy
719 code on X86 processors. It also may be needed by software like
720 XFree86 to initialize some video cards via BIOS. Disabling this
721 option saves about 6k.
724 tristate "Toshiba Laptop support"
727 This adds a driver to safely access the System Management Mode of
728 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
729 not work on models with a Phoenix BIOS. The System Management Mode
730 is used to set the BIOS and power saving options on Toshiba portables.
732 For information on utilities to make use of this driver see the
733 Toshiba Linux utilities web site at:
734 <http://www.buzzard.org.uk/toshiba/>.
736 Say Y if you intend to run this kernel on a Toshiba portable.
740 tristate "Dell laptop support"
742 This adds a driver to safely access the System Management Mode
743 of the CPU on the Dell Inspiron 8000. The System Management Mode
744 is used to read cpu temperature and cooling fan status and to
745 control the fans on the I8K portables.
747 This driver has been tested only on the Inspiron 8000 but it may
748 also work with other Dell laptops. You can force loading on other
749 models by passing the parameter `force=1' to the module. Use at
752 For information on utilities to make use of this driver see the
753 I8K Linux utilities web site at:
754 <http://people.debian.org/~dz/i8k/>
756 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
759 config X86_REBOOTFIXUPS
760 bool "Enable X86 board specific fixups for reboot"
763 This enables chipset and/or board specific fixups to be done
764 in order to get reboot to work correctly. This is only needed on
765 some combinations of hardware and BIOS. The symptom, for which
766 this config is intended, is when reboot ends with a stalled/hung
769 Currently, the only fixup is for the Geode machines using
770 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
772 Say Y if you want to enable the fixup. Currently, it's safe to
773 enable this option even if you don't need it.
777 tristate "/dev/cpu/microcode - microcode support"
780 If you say Y here, you will be able to update the microcode on
781 certain Intel and AMD processors. The Intel support is for the
782 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
783 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
784 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
785 You will obviously need the actual microcode binary data itself
786 which is not shipped with the Linux kernel.
788 This option selects the general module only, you need to select
789 at least one vendor specific module as well.
791 To compile this driver as a module, choose M here: the
792 module will be called microcode.
794 config MICROCODE_INTEL
795 bool "Intel microcode patch loading support"
800 This options enables microcode patch loading support for Intel
803 For latest news and information on obtaining all the required
804 Intel ingredients for this driver, check:
805 <http://www.urbanmyth.org/microcode/>.
808 bool "AMD microcode patch loading support"
812 If you select this option, microcode patch loading support for AMD
813 processors will be enabled.
815 config MICROCODE_OLD_INTERFACE
820 tristate "/dev/cpu/*/msr - Model-specific register support"
822 This device gives privileged processes access to the x86
823 Model-Specific Registers (MSRs). It is a character device with
824 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
825 MSR accesses are directed to a specific CPU on multi-processor
829 tristate "/dev/cpu/*/cpuid - CPU information support"
831 This device gives processes access to the x86 CPUID instruction to
832 be executed on a specific processor. It is a character device
833 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
837 prompt "High Memory Support"
838 default HIGHMEM4G if !X86_NUMAQ
839 default HIGHMEM64G if X86_NUMAQ
844 depends on !X86_NUMAQ
846 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
847 However, the address space of 32-bit x86 processors is only 4
848 Gigabytes large. That means that, if you have a large amount of
849 physical memory, not all of it can be "permanently mapped" by the
850 kernel. The physical memory that's not permanently mapped is called
853 If you are compiling a kernel which will never run on a machine with
854 more than 1 Gigabyte total physical RAM, answer "off" here (default
855 choice and suitable for most users). This will result in a "3GB/1GB"
856 split: 3GB are mapped so that each process sees a 3GB virtual memory
857 space and the remaining part of the 4GB virtual memory space is used
858 by the kernel to permanently map as much physical memory as
861 If the machine has between 1 and 4 Gigabytes physical RAM, then
864 If more than 4 Gigabytes is used then answer "64GB" here. This
865 selection turns Intel PAE (Physical Address Extension) mode on.
866 PAE implements 3-level paging on IA32 processors. PAE is fully
867 supported by Linux, PAE mode is implemented on all recent Intel
868 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
869 then the kernel will not boot on CPUs that don't support PAE!
871 The actual amount of total physical memory will either be
872 auto detected or can be forced by using a kernel command line option
873 such as "mem=256M". (Try "man bootparam" or see the documentation of
874 your boot loader (lilo or loadlin) about how to pass options to the
875 kernel at boot time.)
877 If unsure, say "off".
881 depends on !X86_NUMAQ
883 Select this if you have a 32-bit processor and between 1 and 4
884 gigabytes of physical RAM.
888 depends on !M386 && !M486
891 Select this if you have a 32-bit processor and more than 4
892 gigabytes of physical RAM.
897 depends on EXPERIMENTAL
898 prompt "Memory split" if EMBEDDED
902 Select the desired split between kernel and user memory.
904 If the address range available to the kernel is less than the
905 physical memory installed, the remaining memory will be available
906 as "high memory". Accessing high memory is a little more costly
907 than low memory, as it needs to be mapped into the kernel first.
908 Note that increasing the kernel address space limits the range
909 available to user programs, making the address space there
910 tighter. Selecting anything other than the default 3G/1G split
911 will also likely make your kernel incompatible with binary-only
914 If you are not absolutely sure what you are doing, leave this
918 bool "3G/1G user/kernel split"
919 config VMSPLIT_3G_OPT
921 bool "3G/1G user/kernel split (for full 1G low memory)"
923 bool "2G/2G user/kernel split"
924 config VMSPLIT_2G_OPT
926 bool "2G/2G user/kernel split (for full 2G low memory)"
928 bool "1G/3G user/kernel split"
933 default 0xB0000000 if VMSPLIT_3G_OPT
934 default 0x80000000 if VMSPLIT_2G
935 default 0x78000000 if VMSPLIT_2G_OPT
936 default 0x40000000 if VMSPLIT_1G
942 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
945 bool "PAE (Physical Address Extension) Support"
946 depends on X86_32 && !HIGHMEM4G
948 PAE is required for NX support, and furthermore enables
949 larger swapspace support for non-overcommit purposes. It
950 has the cost of more pagetable lookup overhead, and also
951 consumes more pagetable space per process.
953 config ARCH_PHYS_ADDR_T_64BIT
954 def_bool X86_64 || X86_PAE
956 # Common NUMA Features
958 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
960 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
962 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
964 Enable NUMA (Non Uniform Memory Access) support.
965 The kernel will try to allocate memory used by a CPU on the
966 local memory controller of the CPU and add some more
967 NUMA awareness to the kernel.
969 For 32-bit this is currently highly experimental and should be only
970 used for kernel development. It might also cause boot failures.
971 For 64-bit this is recommended on all multiprocessor Opteron systems.
972 If the system is EM64T, you should say N unless your system is
975 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
976 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
980 prompt "Old style AMD Opteron NUMA detection"
981 depends on X86_64 && NUMA && PCI
983 Enable K8 NUMA node topology detection. You should say Y here if
984 you have a multi processor AMD K8 system. This uses an old
985 method to read the NUMA configuration directly from the builtin
986 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
987 instead, which also takes priority if both are compiled in.
989 config X86_64_ACPI_NUMA
991 prompt "ACPI NUMA detection"
992 depends on X86_64 && NUMA && ACPI && PCI
995 Enable ACPI SRAT based node topology detection.
997 # Some NUMA nodes have memory ranges that span
998 # other nodes. Even though a pfn is valid and
999 # between a node's start and end pfns, it may not
1000 # reside on that node. See memmap_init_zone()
1002 config NODES_SPAN_OTHER_NODES
1004 depends on X86_64_ACPI_NUMA
1007 bool "NUMA emulation"
1008 depends on X86_64 && NUMA
1010 Enable NUMA emulation. A flat machine will be split
1011 into virtual nodes when booted with "numa=fake=N", where N is the
1012 number of nodes. This is only useful for debugging.
1015 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1017 default "9" if MAXSMP
1018 default "6" if X86_64
1019 default "4" if X86_NUMAQ
1021 depends on NEED_MULTIPLE_NODES
1023 Specify the maximum number of NUMA Nodes available on the target
1024 system. Increases memory reserved to accomodate various tables.
1026 config HAVE_ARCH_BOOTMEM_NODE
1028 depends on X86_32 && NUMA
1030 config ARCH_HAVE_MEMORY_PRESENT
1032 depends on X86_32 && DISCONTIGMEM
1034 config NEED_NODE_MEMMAP_SIZE
1036 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1038 config HAVE_ARCH_ALLOC_REMAP
1040 depends on X86_32 && NUMA
1042 config ARCH_FLATMEM_ENABLE
1044 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1046 config ARCH_DISCONTIGMEM_ENABLE
1048 depends on NUMA && X86_32
1050 config ARCH_DISCONTIGMEM_DEFAULT
1052 depends on NUMA && X86_32
1054 config ARCH_SPARSEMEM_DEFAULT
1058 config ARCH_SPARSEMEM_ENABLE
1060 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH
1061 select SPARSEMEM_STATIC if X86_32
1062 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1064 config ARCH_SELECT_MEMORY_MODEL
1066 depends on ARCH_SPARSEMEM_ENABLE
1068 config ARCH_MEMORY_PROBE
1070 depends on MEMORY_HOTPLUG
1075 bool "Allocate 3rd-level pagetables from highmem"
1076 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1078 The VM uses one page table entry for each page of physical memory.
1079 For systems with a lot of RAM, this can be wasteful of precious
1080 low memory. Setting this option will put user-space page table
1081 entries in high memory.
1083 config X86_CHECK_BIOS_CORRUPTION
1084 bool "Check for low memory corruption"
1086 Periodically check for memory corruption in low memory, which
1087 is suspected to be caused by BIOS. Even when enabled in the
1088 configuration, it is disabled at runtime. Enable it by
1089 setting "memory_corruption_check=1" on the kernel command
1090 line. By default it scans the low 64k of memory every 60
1091 seconds; see the memory_corruption_check_size and
1092 memory_corruption_check_period parameters in
1093 Documentation/kernel-parameters.txt to adjust this.
1095 When enabled with the default parameters, this option has
1096 almost no overhead, as it reserves a relatively small amount
1097 of memory and scans it infrequently. It both detects corruption
1098 and prevents it from affecting the running system.
1100 It is, however, intended as a diagnostic tool; if repeatable
1101 BIOS-originated corruption always affects the same memory,
1102 you can use memmap= to prevent the kernel from using that
1105 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1106 bool "Set the default setting of memory_corruption_check"
1107 depends on X86_CHECK_BIOS_CORRUPTION
1110 Set whether the default state of memory_corruption_check is
1113 config X86_RESERVE_LOW_64K
1114 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1117 Reserve the first 64K of physical RAM on BIOSes that are known
1118 to potentially corrupt that memory range. A numbers of BIOSes are
1119 known to utilize this area during suspend/resume, so it must not
1120 be used by the kernel.
1122 Set this to N if you are absolutely sure that you trust the BIOS
1123 to get all its memory reservations and usages right.
1125 If you have doubts about the BIOS (e.g. suspend/resume does not
1126 work or there's kernel crashes after certain hardware hotplug
1127 events) and it's not AMI or Phoenix, then you might want to enable
1128 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1129 corruption patterns.
1133 config MATH_EMULATION
1135 prompt "Math emulation" if X86_32
1137 Linux can emulate a math coprocessor (used for floating point
1138 operations) if you don't have one. 486DX and Pentium processors have
1139 a math coprocessor built in, 486SX and 386 do not, unless you added
1140 a 487DX or 387, respectively. (The messages during boot time can
1141 give you some hints here ["man dmesg"].) Everyone needs either a
1142 coprocessor or this emulation.
1144 If you don't have a math coprocessor, you need to say Y here; if you
1145 say Y here even though you have a coprocessor, the coprocessor will
1146 be used nevertheless. (This behavior can be changed with the kernel
1147 command line option "no387", which comes handy if your coprocessor
1148 is broken. Try "man bootparam" or see the documentation of your boot
1149 loader (lilo or loadlin) about how to pass options to the kernel at
1150 boot time.) This means that it is a good idea to say Y here if you
1151 intend to use this kernel on different machines.
1153 More information about the internals of the Linux math coprocessor
1154 emulation can be found in <file:arch/x86/math-emu/README>.
1156 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1157 kernel, it won't hurt.
1160 bool "MTRR (Memory Type Range Register) support"
1162 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1163 the Memory Type Range Registers (MTRRs) may be used to control
1164 processor access to memory ranges. This is most useful if you have
1165 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1166 allows bus write transfers to be combined into a larger transfer
1167 before bursting over the PCI/AGP bus. This can increase performance
1168 of image write operations 2.5 times or more. Saying Y here creates a
1169 /proc/mtrr file which may be used to manipulate your processor's
1170 MTRRs. Typically the X server should use this.
1172 This code has a reasonably generic interface so that similar
1173 control registers on other processors can be easily supported
1176 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1177 Registers (ARRs) which provide a similar functionality to MTRRs. For
1178 these, the ARRs are used to emulate the MTRRs.
1179 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1180 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1181 write-combining. All of these processors are supported by this code
1182 and it makes sense to say Y here if you have one of them.
1184 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1185 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1186 can lead to all sorts of problems, so it's good to say Y here.
1188 You can safely say Y even if your machine doesn't have MTRRs, you'll
1189 just add about 9 KB to your kernel.
1191 See <file:Documentation/x86/mtrr.txt> for more information.
1193 config MTRR_SANITIZER
1195 prompt "MTRR cleanup support"
1198 Convert MTRR layout from continuous to discrete, so X drivers can
1199 add writeback entries.
1201 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1202 The largest mtrr entry size for a continous block can be set with
1207 config MTRR_SANITIZER_ENABLE_DEFAULT
1208 int "MTRR cleanup enable value (0-1)"
1211 depends on MTRR_SANITIZER
1213 Enable mtrr cleanup default value
1215 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1216 int "MTRR cleanup spare reg num (0-7)"
1219 depends on MTRR_SANITIZER
1221 mtrr cleanup spare entries default, it can be changed via
1222 mtrr_spare_reg_nr=N on the kernel command line.
1226 prompt "x86 PAT support"
1229 Use PAT attributes to setup page level cache control.
1231 PATs are the modern equivalents of MTRRs and are much more
1232 flexible than MTRRs.
1234 Say N here if you see bootup problems (boot crash, boot hang,
1235 spontaneous reboots) or a non-working video driver.
1240 bool "EFI runtime service support"
1243 This enables the kernel to use EFI runtime services that are
1244 available (such as the EFI variable services).
1246 This option is only useful on systems that have EFI firmware.
1247 In addition, you should use the latest ELILO loader available
1248 at <http://elilo.sourceforge.net> in order to take advantage
1249 of EFI runtime services. However, even with this option, the
1250 resultant kernel should continue to boot on existing non-EFI
1255 prompt "Enable seccomp to safely compute untrusted bytecode"
1257 This kernel feature is useful for number crunching applications
1258 that may need to compute untrusted bytecode during their
1259 execution. By using pipes or other transports made available to
1260 the process as file descriptors supporting the read/write
1261 syscalls, it's possible to isolate those applications in
1262 their own address space using seccomp. Once seccomp is
1263 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1264 and the task is only allowed to execute a few safe syscalls
1265 defined by each seccomp mode.
1267 If unsure, say Y. Only embedded should say N here.
1269 config CC_STACKPROTECTOR
1270 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1271 depends on X86_64 && EXPERIMENTAL && BROKEN
1273 This option turns on the -fstack-protector GCC feature. This
1274 feature puts, at the beginning of critical functions, a canary
1275 value on the stack just before the return address, and validates
1276 the value just before actually returning. Stack based buffer
1277 overflows (that need to overwrite this return address) now also
1278 overwrite the canary, which gets detected and the attack is then
1279 neutralized via a kernel panic.
1281 This feature requires gcc version 4.2 or above, or a distribution
1282 gcc with the feature backported. Older versions are automatically
1283 detected and for those versions, this configuration option is ignored.
1285 config CC_STACKPROTECTOR_ALL
1286 bool "Use stack-protector for all functions"
1287 depends on CC_STACKPROTECTOR
1289 Normally, GCC only inserts the canary value protection for
1290 functions that use large-ish on-stack buffers. By enabling
1291 this option, GCC will be asked to do this for ALL functions.
1293 source kernel/Kconfig.hz
1296 bool "kexec system call"
1297 depends on X86_BIOS_REBOOT
1299 kexec is a system call that implements the ability to shutdown your
1300 current kernel, and to start another kernel. It is like a reboot
1301 but it is independent of the system firmware. And like a reboot
1302 you can start any kernel with it, not just Linux.
1304 The name comes from the similarity to the exec system call.
1306 It is an ongoing process to be certain the hardware in a machine
1307 is properly shutdown, so do not be surprised if this code does not
1308 initially work for you. It may help to enable device hotplugging
1309 support. As of this writing the exact hardware interface is
1310 strongly in flux, so no good recommendation can be made.
1313 bool "kernel crash dumps"
1314 depends on X86_64 || (X86_32 && HIGHMEM)
1316 Generate crash dump after being started by kexec.
1317 This should be normally only set in special crash dump kernels
1318 which are loaded in the main kernel with kexec-tools into
1319 a specially reserved region and then later executed after
1320 a crash by kdump/kexec. The crash dump kernel must be compiled
1321 to a memory address not used by the main kernel or BIOS using
1322 PHYSICAL_START, or it must be built as a relocatable image
1323 (CONFIG_RELOCATABLE=y).
1324 For more details see Documentation/kdump/kdump.txt
1327 bool "kexec jump (EXPERIMENTAL)"
1328 depends on EXPERIMENTAL
1329 depends on KEXEC && HIBERNATION && X86_32
1331 Jump between original kernel and kexeced kernel and invoke
1332 code in physical address mode via KEXEC
1334 config PHYSICAL_START
1335 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1336 default "0x1000000" if X86_NUMAQ
1337 default "0x200000" if X86_64
1340 This gives the physical address where the kernel is loaded.
1342 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1343 bzImage will decompress itself to above physical address and
1344 run from there. Otherwise, bzImage will run from the address where
1345 it has been loaded by the boot loader and will ignore above physical
1348 In normal kdump cases one does not have to set/change this option
1349 as now bzImage can be compiled as a completely relocatable image
1350 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1351 address. This option is mainly useful for the folks who don't want
1352 to use a bzImage for capturing the crash dump and want to use a
1353 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1354 to be specifically compiled to run from a specific memory area
1355 (normally a reserved region) and this option comes handy.
1357 So if you are using bzImage for capturing the crash dump, leave
1358 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1359 Otherwise if you plan to use vmlinux for capturing the crash dump
1360 change this value to start of the reserved region (Typically 16MB
1361 0x1000000). In other words, it can be set based on the "X" value as
1362 specified in the "crashkernel=YM@XM" command line boot parameter
1363 passed to the panic-ed kernel. Typically this parameter is set as
1364 crashkernel=64M@16M. Please take a look at
1365 Documentation/kdump/kdump.txt for more details about crash dumps.
1367 Usage of bzImage for capturing the crash dump is recommended as
1368 one does not have to build two kernels. Same kernel can be used
1369 as production kernel and capture kernel. Above option should have
1370 gone away after relocatable bzImage support is introduced. But it
1371 is present because there are users out there who continue to use
1372 vmlinux for dump capture. This option should go away down the
1375 Don't change this unless you know what you are doing.
1378 bool "Build a relocatable kernel (EXPERIMENTAL)"
1379 depends on EXPERIMENTAL
1381 This builds a kernel image that retains relocation information
1382 so it can be loaded someplace besides the default 1MB.
1383 The relocations tend to make the kernel binary about 10% larger,
1384 but are discarded at runtime.
1386 One use is for the kexec on panic case where the recovery kernel
1387 must live at a different physical address than the primary
1390 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1391 it has been loaded at and the compile time physical address
1392 (CONFIG_PHYSICAL_START) is ignored.
1394 config PHYSICAL_ALIGN
1396 prompt "Alignment value to which kernel should be aligned" if X86_32
1397 default "0x100000" if X86_32
1398 default "0x200000" if X86_64
1399 range 0x2000 0x400000
1401 This value puts the alignment restrictions on physical address
1402 where kernel is loaded and run from. Kernel is compiled for an
1403 address which meets above alignment restriction.
1405 If bootloader loads the kernel at a non-aligned address and
1406 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1407 address aligned to above value and run from there.
1409 If bootloader loads the kernel at a non-aligned address and
1410 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1411 load address and decompress itself to the address it has been
1412 compiled for and run from there. The address for which kernel is
1413 compiled already meets above alignment restrictions. Hence the
1414 end result is that kernel runs from a physical address meeting
1415 above alignment restrictions.
1417 Don't change this unless you know what you are doing.
1420 bool "Support for hot-pluggable CPUs"
1421 depends on SMP && HOTPLUG && !X86_VOYAGER
1423 Say Y here to allow turning CPUs off and on. CPUs can be
1424 controlled through /sys/devices/system/cpu.
1425 ( Note: power management support will enable this option
1426 automatically on SMP systems. )
1427 Say N if you want to disable CPU hotplug.
1431 prompt "Compat VDSO support"
1432 depends on X86_32 || IA32_EMULATION
1434 Map the 32-bit VDSO to the predictable old-style address too.
1436 Say N here if you are running a sufficiently recent glibc
1437 version (2.3.3 or later), to remove the high-mapped
1438 VDSO mapping and to exclusively use the randomized VDSO.
1443 bool "Built-in kernel command line"
1446 Allow for specifying boot arguments to the kernel at
1447 build time. On some systems (e.g. embedded ones), it is
1448 necessary or convenient to provide some or all of the
1449 kernel boot arguments with the kernel itself (that is,
1450 to not rely on the boot loader to provide them.)
1452 To compile command line arguments into the kernel,
1453 set this option to 'Y', then fill in the
1454 the boot arguments in CONFIG_CMDLINE.
1456 Systems with fully functional boot loaders (i.e. non-embedded)
1457 should leave this option set to 'N'.
1460 string "Built-in kernel command string"
1461 depends on CMDLINE_BOOL
1464 Enter arguments here that should be compiled into the kernel
1465 image and used at boot time. If the boot loader provides a
1466 command line at boot time, it is appended to this string to
1467 form the full kernel command line, when the system boots.
1469 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1470 change this behavior.
1472 In most cases, the command line (whether built-in or provided
1473 by the boot loader) should specify the device for the root
1476 config CMDLINE_OVERRIDE
1477 bool "Built-in command line overrides boot loader arguments"
1479 depends on CMDLINE_BOOL
1481 Set this option to 'Y' to have the kernel ignore the boot loader
1482 command line, and use ONLY the built-in command line.
1484 This is used to work around broken boot loaders. This should
1485 be set to 'N' under normal conditions.
1489 config ARCH_ENABLE_MEMORY_HOTPLUG
1491 depends on X86_64 || (X86_32 && HIGHMEM)
1493 config HAVE_ARCH_EARLY_PFN_TO_NID
1497 menu "Power management options"
1498 depends on !X86_VOYAGER
1500 config ARCH_HIBERNATION_HEADER
1502 depends on X86_64 && HIBERNATION
1504 source "kernel/power/Kconfig"
1506 source "drivers/acpi/Kconfig"
1511 depends on APM || APM_MODULE
1514 tristate "APM (Advanced Power Management) BIOS support"
1515 depends on X86_32 && PM_SLEEP
1517 APM is a BIOS specification for saving power using several different
1518 techniques. This is mostly useful for battery powered laptops with
1519 APM compliant BIOSes. If you say Y here, the system time will be
1520 reset after a RESUME operation, the /proc/apm device will provide
1521 battery status information, and user-space programs will receive
1522 notification of APM "events" (e.g. battery status change).
1524 If you select "Y" here, you can disable actual use of the APM
1525 BIOS by passing the "apm=off" option to the kernel at boot time.
1527 Note that the APM support is almost completely disabled for
1528 machines with more than one CPU.
1530 In order to use APM, you will need supporting software. For location
1531 and more information, read <file:Documentation/power/pm.txt> and the
1532 Battery Powered Linux mini-HOWTO, available from
1533 <http://www.tldp.org/docs.html#howto>.
1535 This driver does not spin down disk drives (see the hdparm(8)
1536 manpage ("man 8 hdparm") for that), and it doesn't turn off
1537 VESA-compliant "green" monitors.
1539 This driver does not support the TI 4000M TravelMate and the ACER
1540 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1541 desktop machines also don't have compliant BIOSes, and this driver
1542 may cause those machines to panic during the boot phase.
1544 Generally, if you don't have a battery in your machine, there isn't
1545 much point in using this driver and you should say N. If you get
1546 random kernel OOPSes or reboots that don't seem to be related to
1547 anything, try disabling/enabling this option (or disabling/enabling
1550 Some other things you should try when experiencing seemingly random,
1553 1) make sure that you have enough swap space and that it is
1555 2) pass the "no-hlt" option to the kernel
1556 3) switch on floating point emulation in the kernel and pass
1557 the "no387" option to the kernel
1558 4) pass the "floppy=nodma" option to the kernel
1559 5) pass the "mem=4M" option to the kernel (thereby disabling
1560 all but the first 4 MB of RAM)
1561 6) make sure that the CPU is not over clocked.
1562 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1563 8) disable the cache from your BIOS settings
1564 9) install a fan for the video card or exchange video RAM
1565 10) install a better fan for the CPU
1566 11) exchange RAM chips
1567 12) exchange the motherboard.
1569 To compile this driver as a module, choose M here: the
1570 module will be called apm.
1574 config APM_IGNORE_USER_SUSPEND
1575 bool "Ignore USER SUSPEND"
1577 This option will ignore USER SUSPEND requests. On machines with a
1578 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1579 series notebooks, it is necessary to say Y because of a BIOS bug.
1581 config APM_DO_ENABLE
1582 bool "Enable PM at boot time"
1584 Enable APM features at boot time. From page 36 of the APM BIOS
1585 specification: "When disabled, the APM BIOS does not automatically
1586 power manage devices, enter the Standby State, enter the Suspend
1587 State, or take power saving steps in response to CPU Idle calls."
1588 This driver will make CPU Idle calls when Linux is idle (unless this
1589 feature is turned off -- see "Do CPU IDLE calls", below). This
1590 should always save battery power, but more complicated APM features
1591 will be dependent on your BIOS implementation. You may need to turn
1592 this option off if your computer hangs at boot time when using APM
1593 support, or if it beeps continuously instead of suspending. Turn
1594 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1595 T400CDT. This is off by default since most machines do fine without
1599 bool "Make CPU Idle calls when idle"
1601 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1602 On some machines, this can activate improved power savings, such as
1603 a slowed CPU clock rate, when the machine is idle. These idle calls
1604 are made after the idle loop has run for some length of time (e.g.,
1605 333 mS). On some machines, this will cause a hang at boot time or
1606 whenever the CPU becomes idle. (On machines with more than one CPU,
1607 this option does nothing.)
1609 config APM_DISPLAY_BLANK
1610 bool "Enable console blanking using APM"
1612 Enable console blanking using the APM. Some laptops can use this to
1613 turn off the LCD backlight when the screen blanker of the Linux
1614 virtual console blanks the screen. Note that this is only used by
1615 the virtual console screen blanker, and won't turn off the backlight
1616 when using the X Window system. This also doesn't have anything to
1617 do with your VESA-compliant power-saving monitor. Further, this
1618 option doesn't work for all laptops -- it might not turn off your
1619 backlight at all, or it might print a lot of errors to the console,
1620 especially if you are using gpm.
1622 config APM_ALLOW_INTS
1623 bool "Allow interrupts during APM BIOS calls"
1625 Normally we disable external interrupts while we are making calls to
1626 the APM BIOS as a measure to lessen the effects of a badly behaving
1627 BIOS implementation. The BIOS should reenable interrupts if it
1628 needs to. Unfortunately, some BIOSes do not -- especially those in
1629 many of the newer IBM Thinkpads. If you experience hangs when you
1630 suspend, try setting this to Y. Otherwise, say N.
1632 config APM_REAL_MODE_POWER_OFF
1633 bool "Use real mode APM BIOS call to power off"
1635 Use real mode APM BIOS calls to switch off the computer. This is
1636 a work-around for a number of buggy BIOSes. Switch this option on if
1637 your computer crashes instead of powering off properly.
1641 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1643 source "drivers/cpuidle/Kconfig"
1645 source "drivers/idle/Kconfig"
1650 menu "Bus options (PCI etc.)"
1655 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1657 Find out whether you have a PCI motherboard. PCI is the name of a
1658 bus system, i.e. the way the CPU talks to the other stuff inside
1659 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1660 VESA. If you have PCI, say Y, otherwise N.
1663 prompt "PCI access mode"
1664 depends on X86_32 && PCI
1667 On PCI systems, the BIOS can be used to detect the PCI devices and
1668 determine their configuration. However, some old PCI motherboards
1669 have BIOS bugs and may crash if this is done. Also, some embedded
1670 PCI-based systems don't have any BIOS at all. Linux can also try to
1671 detect the PCI hardware directly without using the BIOS.
1673 With this option, you can specify how Linux should detect the
1674 PCI devices. If you choose "BIOS", the BIOS will be used,
1675 if you choose "Direct", the BIOS won't be used, and if you
1676 choose "MMConfig", then PCI Express MMCONFIG will be used.
1677 If you choose "Any", the kernel will try MMCONFIG, then the
1678 direct access method and falls back to the BIOS if that doesn't
1679 work. If unsure, go with the default, which is "Any".
1684 config PCI_GOMMCONFIG
1701 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1703 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1706 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1710 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1714 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1721 bool "Support mmconfig PCI config space access"
1722 depends on X86_64 && PCI && ACPI
1725 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1726 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1728 DMA remapping (DMAR) devices support enables independent address
1729 translations for Direct Memory Access (DMA) from devices.
1730 These DMA remapping devices are reported via ACPI tables
1731 and include PCI device scope covered by these DMA
1736 prompt "Support for Graphics workaround"
1739 Current Graphics drivers tend to use physical address
1740 for DMA and avoid using DMA APIs. Setting this config
1741 option permits the IOMMU driver to set a unity map for
1742 all the OS-visible memory. Hence the driver can continue
1743 to use physical addresses for DMA.
1745 config DMAR_FLOPPY_WA
1749 Floppy disk drivers are know to bypass DMA API calls
1750 thereby failing to work when IOMMU is enabled. This
1751 workaround will setup a 1:1 mapping for the first
1752 16M to make floppy (an ISA device) work.
1755 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1756 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1758 Supports Interrupt remapping for IO-APIC and MSI devices.
1759 To use x2apic mode in the CPU's which support x2APIC enhancements or
1760 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1762 source "drivers/pci/pcie/Kconfig"
1764 source "drivers/pci/Kconfig"
1766 # x86_64 have no ISA slots, but do have ISA-style DMA.
1774 depends on !X86_VOYAGER
1776 Find out whether you have ISA slots on your motherboard. ISA is the
1777 name of a bus system, i.e. the way the CPU talks to the other stuff
1778 inside your box. Other bus systems are PCI, EISA, MicroChannel
1779 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1780 newer boards don't support it. If you have ISA, say Y, otherwise N.
1786 The Extended Industry Standard Architecture (EISA) bus was
1787 developed as an open alternative to the IBM MicroChannel bus.
1789 The EISA bus provided some of the features of the IBM MicroChannel
1790 bus while maintaining backward compatibility with cards made for
1791 the older ISA bus. The EISA bus saw limited use between 1988 and
1792 1995 when it was made obsolete by the PCI bus.
1794 Say Y here if you are building a kernel for an EISA-based machine.
1798 source "drivers/eisa/Kconfig"
1801 bool "MCA support" if !X86_VOYAGER
1802 default y if X86_VOYAGER
1804 MicroChannel Architecture is found in some IBM PS/2 machines and
1805 laptops. It is a bus system similar to PCI or ISA. See
1806 <file:Documentation/mca.txt> (and especially the web page given
1807 there) before attempting to build an MCA bus kernel.
1809 source "drivers/mca/Kconfig"
1812 tristate "NatSemi SCx200 support"
1813 depends on !X86_VOYAGER
1815 This provides basic support for National Semiconductor's
1816 (now AMD's) Geode processors. The driver probes for the
1817 PCI-IDs of several on-chip devices, so its a good dependency
1818 for other scx200_* drivers.
1820 If compiled as a module, the driver is named scx200.
1822 config SCx200HR_TIMER
1823 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1824 depends on SCx200 && GENERIC_TIME
1827 This driver provides a clocksource built upon the on-chip
1828 27MHz high-resolution timer. Its also a workaround for
1829 NSC Geode SC-1100's buggy TSC, which loses time when the
1830 processor goes idle (as is done by the scheduler). The
1831 other workaround is idle=poll boot option.
1833 config GEODE_MFGPT_TIMER
1835 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1836 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1838 This driver provides a clock event source based on the MFGPT
1839 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1840 MFGPTs have a better resolution and max interval than the
1841 generic PIT, and are suitable for use as high-res timers.
1844 bool "One Laptop Per Child support"
1847 Add support for detecting the unique features of the OLPC
1854 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1856 source "drivers/pcmcia/Kconfig"
1858 source "drivers/pci/hotplug/Kconfig"
1863 menu "Executable file formats / Emulations"
1865 source "fs/Kconfig.binfmt"
1867 config IA32_EMULATION
1868 bool "IA32 Emulation"
1870 select COMPAT_BINFMT_ELF
1872 Include code to run 32-bit programs under a 64-bit kernel. You should
1873 likely turn this on, unless you're 100% sure that you don't have any
1874 32-bit programs left.
1877 tristate "IA32 a.out support"
1878 depends on IA32_EMULATION
1880 Support old a.out binaries in the 32bit emulation.
1884 depends on IA32_EMULATION
1886 config COMPAT_FOR_U64_ALIGNMENT
1890 config SYSVIPC_COMPAT
1892 depends on COMPAT && SYSVIPC
1897 source "net/Kconfig"
1899 source "drivers/Kconfig"
1901 source "drivers/firmware/Kconfig"
1905 source "arch/x86/Kconfig.debug"
1907 source "security/Kconfig"
1909 source "crypto/Kconfig"
1911 source "arch/x86/kvm/Kconfig"
1913 source "lib/Kconfig"
projects / linux-2.6 / blob