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
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_FIND_SMP_CONFIG
236 depends on X86_MPPARSE || X86_VOYAGER
241 bool "Enable MPS table"
242 depends on X86_LOCAL_APIC
244 For old smp systems that do not have proper acpi support. Newer systems
245 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
251 depends on X86_LOCAL_APIC
255 prompt "Subarchitecture Type"
261 Choose this option if your computer is a standard PC or compatible.
267 Select this for an AMD Elan processor.
269 Do not use this option for K6/Athlon/Opteron processors!
271 If unsure, choose "PC-compatible" instead.
275 depends on X86_32 && (SMP || BROKEN) && !PCI
277 Voyager is an MCA-based 32-way capable SMP architecture proprietary
278 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
282 If you do not specifically know you have a Voyager based machine,
283 say N here, otherwise the kernel you build will not be bootable.
285 config X86_GENERICARCH
286 bool "Generic architecture"
289 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
290 subarchitectures. It is intended for a generic binary kernel.
291 if you select them all, kernel will probe it one by one. and will
297 bool "NUMAQ (IBM/Sequent)"
298 depends on SMP && X86_32 && PCI && X86_MPPARSE
301 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
302 NUMA multiquad box. This changes the way that processors are
303 bootstrapped, and uses Clustered Logical APIC addressing mode instead
304 of Flat Logical. You will need a new lynxer.elf file to flash your
305 firmware with - send email to <Martin.Bligh@us.ibm.com>.
308 bool "Summit/EXA (IBM x440)"
309 depends on X86_32 && SMP
311 This option is needed for IBM systems that use the Summit/EXA chipset.
312 In particular, it is needed for the x440.
315 bool "Support for Unisys ES7000 IA32 series"
316 depends on X86_32 && SMP
318 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
319 supposed to run on an IA32-based Unisys ES7000 system.
322 bool "Support for big SMP systems with more than 8 CPUs"
323 depends on X86_32 && SMP
325 This option is needed for the systems that have more than 8 CPUs
326 and if the system is not of any sub-arch type above.
331 bool "Support for ScaleMP vSMP"
333 depends on X86_64 && PCI
335 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
336 supposed to run on these EM64T-based machines. Only choose this option
337 if you have one of these machines.
342 bool "SGI 320/540 (Visual Workstation)"
343 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
345 The SGI Visual Workstation series is an IA32-based workstation
346 based on SGI systems chips with some legacy PC hardware attached.
348 Say Y here to create a kernel to run on the SGI 320 or 540.
350 A kernel compiled for the Visual Workstation will run on general
351 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
354 bool "RDC R-321x SoC"
357 select X86_REBOOTFIXUPS
359 This option is needed for RDC R-321x system-on-chip, also known
361 If you don't have one of these chips, you should say N here.
363 config SCHED_NO_NO_OMIT_FRAME_POINTER
365 prompt "Single-depth WCHAN output"
368 Calculate simpler /proc/<PID>/wchan values. If this option
369 is disabled then wchan values will recurse back to the
370 caller function. This provides more accurate wchan values,
371 at the expense of slightly more scheduling overhead.
373 If in doubt, say "Y".
375 menuconfig PARAVIRT_GUEST
376 bool "Paravirtualized guest support"
378 Say Y here to get to see options related to running Linux under
379 various hypervisors. This option alone does not add any kernel code.
381 If you say N, all options in this submenu will be skipped and disabled.
385 source "arch/x86/xen/Kconfig"
388 bool "VMI Guest support"
391 depends on !X86_VOYAGER
393 VMI provides a paravirtualized interface to the VMware ESX server
394 (it could be used by other hypervisors in theory too, but is not
395 at the moment), by linking the kernel to a GPL-ed ROM module
396 provided by the hypervisor.
399 bool "KVM paravirtualized clock"
401 select PARAVIRT_CLOCK
402 depends on !X86_VOYAGER
404 Turning on this option will allow you to run a paravirtualized clock
405 when running over the KVM hypervisor. Instead of relying on a PIT
406 (or probably other) emulation by the underlying device model, the host
407 provides the guest with timing infrastructure such as time of day, and
411 bool "KVM Guest support"
413 depends on !X86_VOYAGER
415 This option enables various optimizations for running under the KVM
418 source "arch/x86/lguest/Kconfig"
421 bool "Enable paravirtualization code"
422 depends on !X86_VOYAGER
424 This changes the kernel so it can modify itself when it is run
425 under a hypervisor, potentially improving performance significantly
426 over full virtualization. However, when run without a hypervisor
427 the kernel is theoretically slower and slightly larger.
429 config PARAVIRT_CLOCK
435 config PARAVIRT_DEBUG
436 bool "paravirt-ops debugging"
437 depends on PARAVIRT && DEBUG_KERNEL
439 Enable to debug paravirt_ops internals. Specifically, BUG if
440 a paravirt_op is missing when it is called.
445 This option adds a kernel parameter 'memtest', which allows memtest
447 memtest=0, mean disabled; -- default
448 memtest=1, mean do 1 test pattern;
450 memtest=4, mean do 4 test patterns.
451 If you are unsure how to answer this question, answer N.
453 config X86_SUMMIT_NUMA
455 depends on X86_32 && NUMA && X86_GENERICARCH
457 config X86_CYCLONE_TIMER
459 depends on X86_GENERICARCH
461 config ES7000_CLUSTERED_APIC
463 depends on SMP && X86_ES7000 && MPENTIUMIII
465 source "arch/x86/Kconfig.cpu"
469 prompt "HPET Timer Support" if X86_32
471 Use the IA-PC HPET (High Precision Event Timer) to manage
472 time in preference to the PIT and RTC, if a HPET is
474 HPET is the next generation timer replacing legacy 8254s.
475 The HPET provides a stable time base on SMP
476 systems, unlike the TSC, but it is more expensive to access,
477 as it is off-chip. You can find the HPET spec at
478 <http://www.intel.com/hardwaredesign/hpetspec.htm>.
480 You can safely choose Y here. However, HPET will only be
481 activated if the platform and the BIOS support this feature.
482 Otherwise the 8254 will be used for timing services.
484 Choose N to continue using the legacy 8254 timer.
486 config HPET_EMULATE_RTC
488 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
490 # Mark as embedded because too many people got it wrong.
491 # The code disables itself when not needed.
494 bool "Enable DMI scanning" if EMBEDDED
496 Enabled scanning of DMI to identify machine quirks. Say Y
497 here unless you have verified that your setup is not
498 affected by entries in the DMI blacklist. Required by PNP
502 bool "GART IOMMU support" if EMBEDDED
506 depends on X86_64 && PCI
508 Support for full DMA access of devices with 32bit memory access only
509 on systems with more than 3GB. This is usually needed for USB,
510 sound, many IDE/SATA chipsets and some other devices.
511 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
512 based hardware IOMMU and a software bounce buffer based IOMMU used
513 on Intel systems and as fallback.
514 The code is only active when needed (enough memory and limited
515 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
519 bool "IBM Calgary IOMMU support"
521 depends on X86_64 && PCI && EXPERIMENTAL
523 Support for hardware IOMMUs in IBM's xSeries x366 and x460
524 systems. Needed to run systems with more than 3GB of memory
525 properly with 32-bit PCI devices that do not support DAC
526 (Double Address Cycle). Calgary also supports bus level
527 isolation, where all DMAs pass through the IOMMU. This
528 prevents them from going anywhere except their intended
529 destination. This catches hard-to-find kernel bugs and
530 mis-behaving drivers and devices that do not use the DMA-API
531 properly to set up their DMA buffers. The IOMMU can be
532 turned off at boot time with the iommu=off parameter.
533 Normally the kernel will make the right choice by itself.
536 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
538 prompt "Should Calgary be enabled by default?"
539 depends on CALGARY_IOMMU
541 Should Calgary be enabled by default? if you choose 'y', Calgary
542 will be used (if it exists). If you choose 'n', Calgary will not be
543 used even if it exists. If you choose 'n' and would like to use
544 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
548 bool "AMD IOMMU support"
551 depends on X86_64 && PCI && ACPI
553 With this option you can enable support for AMD IOMMU hardware in
554 your system. An IOMMU is a hardware component which provides
555 remapping of DMA memory accesses from devices. With an AMD IOMMU you
556 can isolate the the DMA memory of different devices and protect the
557 system from misbehaving device drivers or hardware.
559 You can find out if your system has an AMD IOMMU if you look into
560 your BIOS for an option to enable it or if you have an IVRS ACPI
563 # need this always selected by IOMMU for the VIA workaround
567 Support for software bounce buffers used on x86-64 systems
568 which don't have a hardware IOMMU (e.g. the current generation
569 of Intel's x86-64 CPUs). Using this PCI devices which can only
570 access 32-bits of memory can be used on systems with more than
571 3 GB of memory. If unsure, say Y.
574 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
577 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
578 depends on X86_64 && SMP && BROKEN
581 Configure maximum number of CPUS and NUMA Nodes for this architecture.
585 int "Maximum number of CPUs (2-512)" if !MAXSMP
588 default "4096" if MAXSMP
589 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
592 This allows you to specify the maximum number of CPUs which this
593 kernel will support. The maximum supported value is 512 and the
594 minimum value which makes sense is 2.
596 This is purely to save memory - each supported CPU adds
597 approximately eight kilobytes to the kernel image.
600 bool "SMT (Hyperthreading) scheduler support"
603 SMT scheduler support improves the CPU scheduler's decision making
604 when dealing with Intel Pentium 4 chips with HyperThreading at a
605 cost of slightly increased overhead in some places. If unsure say
610 prompt "Multi-core scheduler support"
613 Multi-core scheduler support improves the CPU scheduler's decision
614 making when dealing with multi-core CPU chips at a cost of slightly
615 increased overhead in some places. If unsure say N here.
617 source "kernel/Kconfig.preempt"
620 bool "Local APIC support on uniprocessors"
621 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
623 A local APIC (Advanced Programmable Interrupt Controller) is an
624 integrated interrupt controller in the CPU. If you have a single-CPU
625 system which has a processor with a local APIC, you can say Y here to
626 enable and use it. If you say Y here even though your machine doesn't
627 have a local APIC, then the kernel will still run with no slowdown at
628 all. The local APIC supports CPU-generated self-interrupts (timer,
629 performance counters), and the NMI watchdog which detects hard
633 bool "IO-APIC support on uniprocessors"
634 depends on X86_UP_APIC
636 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
637 SMP-capable replacement for PC-style interrupt controllers. Most
638 SMP systems and many recent uniprocessor systems have one.
640 If you have a single-CPU system with an IO-APIC, you can say Y here
641 to use it. If you say Y here even though your machine doesn't have
642 an IO-APIC, then the kernel will still run with no slowdown at all.
644 config X86_LOCAL_APIC
646 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
650 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
652 config X86_VISWS_APIC
654 depends on X86_32 && X86_VISWS
657 bool "Machine Check Exception"
658 depends on !X86_VOYAGER
660 Machine Check Exception support allows the processor to notify the
661 kernel if it detects a problem (e.g. overheating, component failure).
662 The action the kernel takes depends on the severity of the problem,
663 ranging from a warning message on the console, to halting the machine.
664 Your processor must be a Pentium or newer to support this - check the
665 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
666 have a design flaw which leads to false MCE events - hence MCE is
667 disabled on all P5 processors, unless explicitly enabled with "mce"
668 as a boot argument. Similarly, if MCE is built in and creates a
669 problem on some new non-standard machine, you can boot with "nomce"
670 to disable it. MCE support simply ignores non-MCE processors like
671 the 386 and 486, so nearly everyone can say Y here.
675 prompt "Intel MCE features"
676 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
678 Additional support for intel specific MCE features such as
683 prompt "AMD MCE features"
684 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
686 Additional support for AMD specific MCE features such as
687 the DRAM Error Threshold.
689 config X86_MCE_NONFATAL
690 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
691 depends on X86_32 && X86_MCE
693 Enabling this feature starts a timer that triggers every 5 seconds which
694 will look at the machine check registers to see if anything happened.
695 Non-fatal problems automatically get corrected (but still logged).
696 Disable this if you don't want to see these messages.
697 Seeing the messages this option prints out may be indicative of dying
698 or out-of-spec (ie, overclocked) hardware.
699 This option only does something on certain CPUs.
700 (AMD Athlon/Duron and Intel Pentium 4)
702 config X86_MCE_P4THERMAL
703 bool "check for P4 thermal throttling interrupt."
704 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
706 Enabling this feature will cause a message to be printed when the P4
707 enters thermal throttling.
710 bool "Enable VM86 support" if EMBEDDED
714 This option is required by programs like DOSEMU to run 16-bit legacy
715 code on X86 processors. It also may be needed by software like
716 XFree86 to initialize some video cards via BIOS. Disabling this
717 option saves about 6k.
720 tristate "Toshiba Laptop support"
723 This adds a driver to safely access the System Management Mode of
724 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
725 not work on models with a Phoenix BIOS. The System Management Mode
726 is used to set the BIOS and power saving options on Toshiba portables.
728 For information on utilities to make use of this driver see the
729 Toshiba Linux utilities web site at:
730 <http://www.buzzard.org.uk/toshiba/>.
732 Say Y if you intend to run this kernel on a Toshiba portable.
736 tristate "Dell laptop support"
738 This adds a driver to safely access the System Management Mode
739 of the CPU on the Dell Inspiron 8000. The System Management Mode
740 is used to read cpu temperature and cooling fan status and to
741 control the fans on the I8K portables.
743 This driver has been tested only on the Inspiron 8000 but it may
744 also work with other Dell laptops. You can force loading on other
745 models by passing the parameter `force=1' to the module. Use at
748 For information on utilities to make use of this driver see the
749 I8K Linux utilities web site at:
750 <http://people.debian.org/~dz/i8k/>
752 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
755 config X86_REBOOTFIXUPS
756 bool "Enable X86 board specific fixups for reboot"
759 This enables chipset and/or board specific fixups to be done
760 in order to get reboot to work correctly. This is only needed on
761 some combinations of hardware and BIOS. The symptom, for which
762 this config is intended, is when reboot ends with a stalled/hung
765 Currently, the only fixup is for the Geode machines using
766 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
768 Say Y if you want to enable the fixup. Currently, it's safe to
769 enable this option even if you don't need it.
773 tristate "/dev/cpu/microcode - microcode support"
776 If you say Y here, you will be able to update the microcode on
777 certain Intel and AMD processors. The Intel support is for the
778 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
779 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
780 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
781 You will obviously need the actual microcode binary data itself
782 which is not shipped with the Linux kernel.
784 This option selects the general module only, you need to select
785 at least one vendor specific module as well.
787 To compile this driver as a module, choose M here: the
788 module will be called microcode.
790 config MICROCODE_INTEL
791 bool "Intel microcode patch loading support"
796 This options enables microcode patch loading support for Intel
799 For latest news and information on obtaining all the required
800 Intel ingredients for this driver, check:
801 <http://www.urbanmyth.org/microcode/>.
804 bool "AMD microcode patch loading support"
808 If you select this option, microcode patch loading support for AMD
809 processors will be enabled.
811 config MICROCODE_OLD_INTERFACE
816 tristate "/dev/cpu/*/msr - Model-specific register support"
818 This device gives privileged processes access to the x86
819 Model-Specific Registers (MSRs). It is a character device with
820 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
821 MSR accesses are directed to a specific CPU on multi-processor
825 tristate "/dev/cpu/*/cpuid - CPU information support"
827 This device gives processes access to the x86 CPUID instruction to
828 be executed on a specific processor. It is a character device
829 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
833 prompt "High Memory Support"
834 default HIGHMEM4G if !X86_NUMAQ
835 default HIGHMEM64G if X86_NUMAQ
840 depends on !X86_NUMAQ
842 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
843 However, the address space of 32-bit x86 processors is only 4
844 Gigabytes large. That means that, if you have a large amount of
845 physical memory, not all of it can be "permanently mapped" by the
846 kernel. The physical memory that's not permanently mapped is called
849 If you are compiling a kernel which will never run on a machine with
850 more than 1 Gigabyte total physical RAM, answer "off" here (default
851 choice and suitable for most users). This will result in a "3GB/1GB"
852 split: 3GB are mapped so that each process sees a 3GB virtual memory
853 space and the remaining part of the 4GB virtual memory space is used
854 by the kernel to permanently map as much physical memory as
857 If the machine has between 1 and 4 Gigabytes physical RAM, then
860 If more than 4 Gigabytes is used then answer "64GB" here. This
861 selection turns Intel PAE (Physical Address Extension) mode on.
862 PAE implements 3-level paging on IA32 processors. PAE is fully
863 supported by Linux, PAE mode is implemented on all recent Intel
864 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
865 then the kernel will not boot on CPUs that don't support PAE!
867 The actual amount of total physical memory will either be
868 auto detected or can be forced by using a kernel command line option
869 such as "mem=256M". (Try "man bootparam" or see the documentation of
870 your boot loader (lilo or loadlin) about how to pass options to the
871 kernel at boot time.)
873 If unsure, say "off".
877 depends on !X86_NUMAQ
879 Select this if you have a 32-bit processor and between 1 and 4
880 gigabytes of physical RAM.
884 depends on !M386 && !M486
887 Select this if you have a 32-bit processor and more than 4
888 gigabytes of physical RAM.
893 depends on EXPERIMENTAL
894 prompt "Memory split" if EMBEDDED
898 Select the desired split between kernel and user memory.
900 If the address range available to the kernel is less than the
901 physical memory installed, the remaining memory will be available
902 as "high memory". Accessing high memory is a little more costly
903 than low memory, as it needs to be mapped into the kernel first.
904 Note that increasing the kernel address space limits the range
905 available to user programs, making the address space there
906 tighter. Selecting anything other than the default 3G/1G split
907 will also likely make your kernel incompatible with binary-only
910 If you are not absolutely sure what you are doing, leave this
914 bool "3G/1G user/kernel split"
915 config VMSPLIT_3G_OPT
917 bool "3G/1G user/kernel split (for full 1G low memory)"
919 bool "2G/2G user/kernel split"
920 config VMSPLIT_2G_OPT
922 bool "2G/2G user/kernel split (for full 2G low memory)"
924 bool "1G/3G user/kernel split"
929 default 0xB0000000 if VMSPLIT_3G_OPT
930 default 0x80000000 if VMSPLIT_2G
931 default 0x78000000 if VMSPLIT_2G_OPT
932 default 0x40000000 if VMSPLIT_1G
938 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
941 bool "PAE (Physical Address Extension) Support"
942 depends on X86_32 && !HIGHMEM4G
944 PAE is required for NX support, and furthermore enables
945 larger swapspace support for non-overcommit purposes. It
946 has the cost of more pagetable lookup overhead, and also
947 consumes more pagetable space per process.
949 config ARCH_PHYS_ADDR_T_64BIT
950 def_bool X86_64 || X86_PAE
952 # Common NUMA Features
954 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
956 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
958 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
960 Enable NUMA (Non Uniform Memory Access) support.
961 The kernel will try to allocate memory used by a CPU on the
962 local memory controller of the CPU and add some more
963 NUMA awareness to the kernel.
965 For 32-bit this is currently highly experimental and should be only
966 used for kernel development. It might also cause boot failures.
967 For 64-bit this is recommended on all multiprocessor Opteron systems.
968 If the system is EM64T, you should say N unless your system is
971 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
972 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
976 prompt "Old style AMD Opteron NUMA detection"
977 depends on X86_64 && NUMA && PCI
979 Enable K8 NUMA node topology detection. You should say Y here if
980 you have a multi processor AMD K8 system. This uses an old
981 method to read the NUMA configuration directly from the builtin
982 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
983 instead, which also takes priority if both are compiled in.
985 config X86_64_ACPI_NUMA
987 prompt "ACPI NUMA detection"
988 depends on X86_64 && NUMA && ACPI && PCI
991 Enable ACPI SRAT based node topology detection.
993 # Some NUMA nodes have memory ranges that span
994 # other nodes. Even though a pfn is valid and
995 # between a node's start and end pfns, it may not
996 # reside on that node. See memmap_init_zone()
998 config NODES_SPAN_OTHER_NODES
1000 depends on X86_64_ACPI_NUMA
1003 bool "NUMA emulation"
1004 depends on X86_64 && NUMA
1006 Enable NUMA emulation. A flat machine will be split
1007 into virtual nodes when booted with "numa=fake=N", where N is the
1008 number of nodes. This is only useful for debugging.
1011 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1013 default "9" if MAXSMP
1014 default "6" if X86_64
1015 default "4" if X86_NUMAQ
1017 depends on NEED_MULTIPLE_NODES
1019 Specify the maximum number of NUMA Nodes available on the target
1020 system. Increases memory reserved to accomodate various tables.
1022 config HAVE_ARCH_BOOTMEM_NODE
1024 depends on X86_32 && NUMA
1026 config ARCH_HAVE_MEMORY_PRESENT
1028 depends on X86_32 && DISCONTIGMEM
1030 config NEED_NODE_MEMMAP_SIZE
1032 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1034 config HAVE_ARCH_ALLOC_REMAP
1036 depends on X86_32 && NUMA
1038 config ARCH_FLATMEM_ENABLE
1040 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1042 config ARCH_DISCONTIGMEM_ENABLE
1044 depends on NUMA && X86_32
1046 config ARCH_DISCONTIGMEM_DEFAULT
1048 depends on NUMA && X86_32
1050 config ARCH_SPARSEMEM_DEFAULT
1054 config ARCH_SPARSEMEM_ENABLE
1056 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH
1057 select SPARSEMEM_STATIC if X86_32
1058 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1060 config ARCH_SELECT_MEMORY_MODEL
1062 depends on ARCH_SPARSEMEM_ENABLE
1064 config ARCH_MEMORY_PROBE
1066 depends on MEMORY_HOTPLUG
1071 bool "Allocate 3rd-level pagetables from highmem"
1072 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1074 The VM uses one page table entry for each page of physical memory.
1075 For systems with a lot of RAM, this can be wasteful of precious
1076 low memory. Setting this option will put user-space page table
1077 entries in high memory.
1079 config X86_CHECK_BIOS_CORRUPTION
1080 bool "Check for low memory corruption"
1082 Periodically check for memory corruption in low memory, which
1083 is suspected to be caused by BIOS. Even when enabled in the
1084 configuration, it is disabled at runtime. Enable it by
1085 setting "memory_corruption_check=1" on the kernel command
1086 line. By default it scans the low 64k of memory every 60
1087 seconds; see the memory_corruption_check_size and
1088 memory_corruption_check_period parameters in
1089 Documentation/kernel-parameters.txt to adjust this.
1091 When enabled with the default parameters, this option has
1092 almost no overhead, as it reserves a relatively small amount
1093 of memory and scans it infrequently. It both detects corruption
1094 and prevents it from affecting the running system.
1096 It is, however, intended as a diagnostic tool; if repeatable
1097 BIOS-originated corruption always affects the same memory,
1098 you can use memmap= to prevent the kernel from using that
1101 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1102 bool "Set the default setting of memory_corruption_check"
1103 depends on X86_CHECK_BIOS_CORRUPTION
1106 Set whether the default state of memory_corruption_check is
1109 config X86_RESERVE_LOW_64K
1110 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1113 Reserve the first 64K of physical RAM on BIOSes that are known
1114 to potentially corrupt that memory range. A numbers of BIOSes are
1115 known to utilize this area during suspend/resume, so it must not
1116 be used by the kernel.
1118 Set this to N if you are absolutely sure that you trust the BIOS
1119 to get all its memory reservations and usages right.
1121 If you have doubts about the BIOS (e.g. suspend/resume does not
1122 work or there's kernel crashes after certain hardware hotplug
1123 events) and it's not AMI or Phoenix, then you might want to enable
1124 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1125 corruption patterns.
1129 config MATH_EMULATION
1131 prompt "Math emulation" if X86_32
1133 Linux can emulate a math coprocessor (used for floating point
1134 operations) if you don't have one. 486DX and Pentium processors have
1135 a math coprocessor built in, 486SX and 386 do not, unless you added
1136 a 487DX or 387, respectively. (The messages during boot time can
1137 give you some hints here ["man dmesg"].) Everyone needs either a
1138 coprocessor or this emulation.
1140 If you don't have a math coprocessor, you need to say Y here; if you
1141 say Y here even though you have a coprocessor, the coprocessor will
1142 be used nevertheless. (This behavior can be changed with the kernel
1143 command line option "no387", which comes handy if your coprocessor
1144 is broken. Try "man bootparam" or see the documentation of your boot
1145 loader (lilo or loadlin) about how to pass options to the kernel at
1146 boot time.) This means that it is a good idea to say Y here if you
1147 intend to use this kernel on different machines.
1149 More information about the internals of the Linux math coprocessor
1150 emulation can be found in <file:arch/x86/math-emu/README>.
1152 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1153 kernel, it won't hurt.
1156 bool "MTRR (Memory Type Range Register) support"
1158 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1159 the Memory Type Range Registers (MTRRs) may be used to control
1160 processor access to memory ranges. This is most useful if you have
1161 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1162 allows bus write transfers to be combined into a larger transfer
1163 before bursting over the PCI/AGP bus. This can increase performance
1164 of image write operations 2.5 times or more. Saying Y here creates a
1165 /proc/mtrr file which may be used to manipulate your processor's
1166 MTRRs. Typically the X server should use this.
1168 This code has a reasonably generic interface so that similar
1169 control registers on other processors can be easily supported
1172 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1173 Registers (ARRs) which provide a similar functionality to MTRRs. For
1174 these, the ARRs are used to emulate the MTRRs.
1175 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1176 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1177 write-combining. All of these processors are supported by this code
1178 and it makes sense to say Y here if you have one of them.
1180 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1181 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1182 can lead to all sorts of problems, so it's good to say Y here.
1184 You can safely say Y even if your machine doesn't have MTRRs, you'll
1185 just add about 9 KB to your kernel.
1187 See <file:Documentation/x86/mtrr.txt> for more information.
1189 config MTRR_SANITIZER
1191 prompt "MTRR cleanup support"
1194 Convert MTRR layout from continuous to discrete, so X drivers can
1195 add writeback entries.
1197 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1198 The largest mtrr entry size for a continous block can be set with
1203 config MTRR_SANITIZER_ENABLE_DEFAULT
1204 int "MTRR cleanup enable value (0-1)"
1207 depends on MTRR_SANITIZER
1209 Enable mtrr cleanup default value
1211 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1212 int "MTRR cleanup spare reg num (0-7)"
1215 depends on MTRR_SANITIZER
1217 mtrr cleanup spare entries default, it can be changed via
1218 mtrr_spare_reg_nr=N on the kernel command line.
1222 prompt "x86 PAT support"
1225 Use PAT attributes to setup page level cache control.
1227 PATs are the modern equivalents of MTRRs and are much more
1228 flexible than MTRRs.
1230 Say N here if you see bootup problems (boot crash, boot hang,
1231 spontaneous reboots) or a non-working video driver.
1236 bool "EFI runtime service support"
1239 This enables the kernel to use EFI runtime services that are
1240 available (such as the EFI variable services).
1242 This option is only useful on systems that have EFI firmware.
1243 In addition, you should use the latest ELILO loader available
1244 at <http://elilo.sourceforge.net> in order to take advantage
1245 of EFI runtime services. However, even with this option, the
1246 resultant kernel should continue to boot on existing non-EFI
1251 prompt "Enable seccomp to safely compute untrusted bytecode"
1253 This kernel feature is useful for number crunching applications
1254 that may need to compute untrusted bytecode during their
1255 execution. By using pipes or other transports made available to
1256 the process as file descriptors supporting the read/write
1257 syscalls, it's possible to isolate those applications in
1258 their own address space using seccomp. Once seccomp is
1259 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1260 and the task is only allowed to execute a few safe syscalls
1261 defined by each seccomp mode.
1263 If unsure, say Y. Only embedded should say N here.
1265 config CC_STACKPROTECTOR
1266 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1267 depends on X86_64 && EXPERIMENTAL && BROKEN
1269 This option turns on the -fstack-protector GCC feature. This
1270 feature puts, at the beginning of critical functions, a canary
1271 value on the stack just before the return address, and validates
1272 the value just before actually returning. Stack based buffer
1273 overflows (that need to overwrite this return address) now also
1274 overwrite the canary, which gets detected and the attack is then
1275 neutralized via a kernel panic.
1277 This feature requires gcc version 4.2 or above, or a distribution
1278 gcc with the feature backported. Older versions are automatically
1279 detected and for those versions, this configuration option is ignored.
1281 config CC_STACKPROTECTOR_ALL
1282 bool "Use stack-protector for all functions"
1283 depends on CC_STACKPROTECTOR
1285 Normally, GCC only inserts the canary value protection for
1286 functions that use large-ish on-stack buffers. By enabling
1287 this option, GCC will be asked to do this for ALL functions.
1289 source kernel/Kconfig.hz
1292 bool "kexec system call"
1293 depends on X86_BIOS_REBOOT
1295 kexec is a system call that implements the ability to shutdown your
1296 current kernel, and to start another kernel. It is like a reboot
1297 but it is independent of the system firmware. And like a reboot
1298 you can start any kernel with it, not just Linux.
1300 The name comes from the similarity to the exec system call.
1302 It is an ongoing process to be certain the hardware in a machine
1303 is properly shutdown, so do not be surprised if this code does not
1304 initially work for you. It may help to enable device hotplugging
1305 support. As of this writing the exact hardware interface is
1306 strongly in flux, so no good recommendation can be made.
1309 bool "kernel crash dumps"
1310 depends on X86_64 || (X86_32 && HIGHMEM)
1312 Generate crash dump after being started by kexec.
1313 This should be normally only set in special crash dump kernels
1314 which are loaded in the main kernel with kexec-tools into
1315 a specially reserved region and then later executed after
1316 a crash by kdump/kexec. The crash dump kernel must be compiled
1317 to a memory address not used by the main kernel or BIOS using
1318 PHYSICAL_START, or it must be built as a relocatable image
1319 (CONFIG_RELOCATABLE=y).
1320 For more details see Documentation/kdump/kdump.txt
1323 bool "kexec jump (EXPERIMENTAL)"
1324 depends on EXPERIMENTAL
1325 depends on KEXEC && HIBERNATION && X86_32
1327 Jump between original kernel and kexeced kernel and invoke
1328 code in physical address mode via KEXEC
1330 config PHYSICAL_START
1331 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1332 default "0x1000000" if X86_NUMAQ
1333 default "0x200000" if X86_64
1336 This gives the physical address where the kernel is loaded.
1338 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1339 bzImage will decompress itself to above physical address and
1340 run from there. Otherwise, bzImage will run from the address where
1341 it has been loaded by the boot loader and will ignore above physical
1344 In normal kdump cases one does not have to set/change this option
1345 as now bzImage can be compiled as a completely relocatable image
1346 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1347 address. This option is mainly useful for the folks who don't want
1348 to use a bzImage for capturing the crash dump and want to use a
1349 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1350 to be specifically compiled to run from a specific memory area
1351 (normally a reserved region) and this option comes handy.
1353 So if you are using bzImage for capturing the crash dump, leave
1354 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1355 Otherwise if you plan to use vmlinux for capturing the crash dump
1356 change this value to start of the reserved region (Typically 16MB
1357 0x1000000). In other words, it can be set based on the "X" value as
1358 specified in the "crashkernel=YM@XM" command line boot parameter
1359 passed to the panic-ed kernel. Typically this parameter is set as
1360 crashkernel=64M@16M. Please take a look at
1361 Documentation/kdump/kdump.txt for more details about crash dumps.
1363 Usage of bzImage for capturing the crash dump is recommended as
1364 one does not have to build two kernels. Same kernel can be used
1365 as production kernel and capture kernel. Above option should have
1366 gone away after relocatable bzImage support is introduced. But it
1367 is present because there are users out there who continue to use
1368 vmlinux for dump capture. This option should go away down the
1371 Don't change this unless you know what you are doing.
1374 bool "Build a relocatable kernel (EXPERIMENTAL)"
1375 depends on EXPERIMENTAL
1377 This builds a kernel image that retains relocation information
1378 so it can be loaded someplace besides the default 1MB.
1379 The relocations tend to make the kernel binary about 10% larger,
1380 but are discarded at runtime.
1382 One use is for the kexec on panic case where the recovery kernel
1383 must live at a different physical address than the primary
1386 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1387 it has been loaded at and the compile time physical address
1388 (CONFIG_PHYSICAL_START) is ignored.
1390 config PHYSICAL_ALIGN
1392 prompt "Alignment value to which kernel should be aligned" if X86_32
1393 default "0x100000" if X86_32
1394 default "0x200000" if X86_64
1395 range 0x2000 0x400000
1397 This value puts the alignment restrictions on physical address
1398 where kernel is loaded and run from. Kernel is compiled for an
1399 address which meets above alignment restriction.
1401 If bootloader loads the kernel at a non-aligned address and
1402 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1403 address aligned to above value and run from there.
1405 If bootloader loads the kernel at a non-aligned address and
1406 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1407 load address and decompress itself to the address it has been
1408 compiled for and run from there. The address for which kernel is
1409 compiled already meets above alignment restrictions. Hence the
1410 end result is that kernel runs from a physical address meeting
1411 above alignment restrictions.
1413 Don't change this unless you know what you are doing.
1416 bool "Support for hot-pluggable CPUs"
1417 depends on SMP && HOTPLUG && !X86_VOYAGER
1419 Say Y here to allow turning CPUs off and on. CPUs can be
1420 controlled through /sys/devices/system/cpu.
1421 ( Note: power management support will enable this option
1422 automatically on SMP systems. )
1423 Say N if you want to disable CPU hotplug.
1427 prompt "Compat VDSO support"
1428 depends on X86_32 || IA32_EMULATION
1430 Map the 32-bit VDSO to the predictable old-style address too.
1432 Say N here if you are running a sufficiently recent glibc
1433 version (2.3.3 or later), to remove the high-mapped
1434 VDSO mapping and to exclusively use the randomized VDSO.
1439 bool "Built-in kernel command line"
1442 Allow for specifying boot arguments to the kernel at
1443 build time. On some systems (e.g. embedded ones), it is
1444 necessary or convenient to provide some or all of the
1445 kernel boot arguments with the kernel itself (that is,
1446 to not rely on the boot loader to provide them.)
1448 To compile command line arguments into the kernel,
1449 set this option to 'Y', then fill in the
1450 the boot arguments in CONFIG_CMDLINE.
1452 Systems with fully functional boot loaders (i.e. non-embedded)
1453 should leave this option set to 'N'.
1456 string "Built-in kernel command string"
1457 depends on CMDLINE_BOOL
1460 Enter arguments here that should be compiled into the kernel
1461 image and used at boot time. If the boot loader provides a
1462 command line at boot time, it is appended to this string to
1463 form the full kernel command line, when the system boots.
1465 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1466 change this behavior.
1468 In most cases, the command line (whether built-in or provided
1469 by the boot loader) should specify the device for the root
1472 config CMDLINE_OVERRIDE
1473 bool "Built-in command line overrides boot loader arguments"
1475 depends on CMDLINE_BOOL
1477 Set this option to 'Y' to have the kernel ignore the boot loader
1478 command line, and use ONLY the built-in command line.
1480 This is used to work around broken boot loaders. This should
1481 be set to 'N' under normal conditions.
1485 config ARCH_ENABLE_MEMORY_HOTPLUG
1487 depends on X86_64 || (X86_32 && HIGHMEM)
1489 config HAVE_ARCH_EARLY_PFN_TO_NID
1493 menu "Power management options"
1494 depends on !X86_VOYAGER
1496 config ARCH_HIBERNATION_HEADER
1498 depends on X86_64 && HIBERNATION
1500 source "kernel/power/Kconfig"
1502 source "drivers/acpi/Kconfig"
1507 depends on APM || APM_MODULE
1510 tristate "APM (Advanced Power Management) BIOS support"
1511 depends on X86_32 && PM_SLEEP
1513 APM is a BIOS specification for saving power using several different
1514 techniques. This is mostly useful for battery powered laptops with
1515 APM compliant BIOSes. If you say Y here, the system time will be
1516 reset after a RESUME operation, the /proc/apm device will provide
1517 battery status information, and user-space programs will receive
1518 notification of APM "events" (e.g. battery status change).
1520 If you select "Y" here, you can disable actual use of the APM
1521 BIOS by passing the "apm=off" option to the kernel at boot time.
1523 Note that the APM support is almost completely disabled for
1524 machines with more than one CPU.
1526 In order to use APM, you will need supporting software. For location
1527 and more information, read <file:Documentation/power/pm.txt> and the
1528 Battery Powered Linux mini-HOWTO, available from
1529 <http://www.tldp.org/docs.html#howto>.
1531 This driver does not spin down disk drives (see the hdparm(8)
1532 manpage ("man 8 hdparm") for that), and it doesn't turn off
1533 VESA-compliant "green" monitors.
1535 This driver does not support the TI 4000M TravelMate and the ACER
1536 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1537 desktop machines also don't have compliant BIOSes, and this driver
1538 may cause those machines to panic during the boot phase.
1540 Generally, if you don't have a battery in your machine, there isn't
1541 much point in using this driver and you should say N. If you get
1542 random kernel OOPSes or reboots that don't seem to be related to
1543 anything, try disabling/enabling this option (or disabling/enabling
1546 Some other things you should try when experiencing seemingly random,
1549 1) make sure that you have enough swap space and that it is
1551 2) pass the "no-hlt" option to the kernel
1552 3) switch on floating point emulation in the kernel and pass
1553 the "no387" option to the kernel
1554 4) pass the "floppy=nodma" option to the kernel
1555 5) pass the "mem=4M" option to the kernel (thereby disabling
1556 all but the first 4 MB of RAM)
1557 6) make sure that the CPU is not over clocked.
1558 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1559 8) disable the cache from your BIOS settings
1560 9) install a fan for the video card or exchange video RAM
1561 10) install a better fan for the CPU
1562 11) exchange RAM chips
1563 12) exchange the motherboard.
1565 To compile this driver as a module, choose M here: the
1566 module will be called apm.
1570 config APM_IGNORE_USER_SUSPEND
1571 bool "Ignore USER SUSPEND"
1573 This option will ignore USER SUSPEND requests. On machines with a
1574 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1575 series notebooks, it is necessary to say Y because of a BIOS bug.
1577 config APM_DO_ENABLE
1578 bool "Enable PM at boot time"
1580 Enable APM features at boot time. From page 36 of the APM BIOS
1581 specification: "When disabled, the APM BIOS does not automatically
1582 power manage devices, enter the Standby State, enter the Suspend
1583 State, or take power saving steps in response to CPU Idle calls."
1584 This driver will make CPU Idle calls when Linux is idle (unless this
1585 feature is turned off -- see "Do CPU IDLE calls", below). This
1586 should always save battery power, but more complicated APM features
1587 will be dependent on your BIOS implementation. You may need to turn
1588 this option off if your computer hangs at boot time when using APM
1589 support, or if it beeps continuously instead of suspending. Turn
1590 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1591 T400CDT. This is off by default since most machines do fine without
1595 bool "Make CPU Idle calls when idle"
1597 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1598 On some machines, this can activate improved power savings, such as
1599 a slowed CPU clock rate, when the machine is idle. These idle calls
1600 are made after the idle loop has run for some length of time (e.g.,
1601 333 mS). On some machines, this will cause a hang at boot time or
1602 whenever the CPU becomes idle. (On machines with more than one CPU,
1603 this option does nothing.)
1605 config APM_DISPLAY_BLANK
1606 bool "Enable console blanking using APM"
1608 Enable console blanking using the APM. Some laptops can use this to
1609 turn off the LCD backlight when the screen blanker of the Linux
1610 virtual console blanks the screen. Note that this is only used by
1611 the virtual console screen blanker, and won't turn off the backlight
1612 when using the X Window system. This also doesn't have anything to
1613 do with your VESA-compliant power-saving monitor. Further, this
1614 option doesn't work for all laptops -- it might not turn off your
1615 backlight at all, or it might print a lot of errors to the console,
1616 especially if you are using gpm.
1618 config APM_ALLOW_INTS
1619 bool "Allow interrupts during APM BIOS calls"
1621 Normally we disable external interrupts while we are making calls to
1622 the APM BIOS as a measure to lessen the effects of a badly behaving
1623 BIOS implementation. The BIOS should reenable interrupts if it
1624 needs to. Unfortunately, some BIOSes do not -- especially those in
1625 many of the newer IBM Thinkpads. If you experience hangs when you
1626 suspend, try setting this to Y. Otherwise, say N.
1628 config APM_REAL_MODE_POWER_OFF
1629 bool "Use real mode APM BIOS call to power off"
1631 Use real mode APM BIOS calls to switch off the computer. This is
1632 a work-around for a number of buggy BIOSes. Switch this option on if
1633 your computer crashes instead of powering off properly.
1637 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1639 source "drivers/cpuidle/Kconfig"
1641 source "drivers/idle/Kconfig"
1646 menu "Bus options (PCI etc.)"
1651 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1653 Find out whether you have a PCI motherboard. PCI is the name of a
1654 bus system, i.e. the way the CPU talks to the other stuff inside
1655 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1656 VESA. If you have PCI, say Y, otherwise N.
1659 prompt "PCI access mode"
1660 depends on X86_32 && PCI
1663 On PCI systems, the BIOS can be used to detect the PCI devices and
1664 determine their configuration. However, some old PCI motherboards
1665 have BIOS bugs and may crash if this is done. Also, some embedded
1666 PCI-based systems don't have any BIOS at all. Linux can also try to
1667 detect the PCI hardware directly without using the BIOS.
1669 With this option, you can specify how Linux should detect the
1670 PCI devices. If you choose "BIOS", the BIOS will be used,
1671 if you choose "Direct", the BIOS won't be used, and if you
1672 choose "MMConfig", then PCI Express MMCONFIG will be used.
1673 If you choose "Any", the kernel will try MMCONFIG, then the
1674 direct access method and falls back to the BIOS if that doesn't
1675 work. If unsure, go with the default, which is "Any".
1680 config PCI_GOMMCONFIG
1697 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1699 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1702 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1706 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1710 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1717 bool "Support mmconfig PCI config space access"
1718 depends on X86_64 && PCI && ACPI
1721 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1722 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1724 DMA remapping (DMAR) devices support enables independent address
1725 translations for Direct Memory Access (DMA) from devices.
1726 These DMA remapping devices are reported via ACPI tables
1727 and include PCI device scope covered by these DMA
1732 prompt "Support for Graphics workaround"
1735 Current Graphics drivers tend to use physical address
1736 for DMA and avoid using DMA APIs. Setting this config
1737 option permits the IOMMU driver to set a unity map for
1738 all the OS-visible memory. Hence the driver can continue
1739 to use physical addresses for DMA.
1741 config DMAR_FLOPPY_WA
1745 Floppy disk drivers are know to bypass DMA API calls
1746 thereby failing to work when IOMMU is enabled. This
1747 workaround will setup a 1:1 mapping for the first
1748 16M to make floppy (an ISA device) work.
1751 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1752 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1754 Supports Interrupt remapping for IO-APIC and MSI devices.
1755 To use x2apic mode in the CPU's which support x2APIC enhancements or
1756 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1758 source "drivers/pci/pcie/Kconfig"
1760 source "drivers/pci/Kconfig"
1762 # x86_64 have no ISA slots, but do have ISA-style DMA.
1770 depends on !X86_VOYAGER
1772 Find out whether you have ISA slots on your motherboard. ISA is the
1773 name of a bus system, i.e. the way the CPU talks to the other stuff
1774 inside your box. Other bus systems are PCI, EISA, MicroChannel
1775 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1776 newer boards don't support it. If you have ISA, say Y, otherwise N.
1782 The Extended Industry Standard Architecture (EISA) bus was
1783 developed as an open alternative to the IBM MicroChannel bus.
1785 The EISA bus provided some of the features of the IBM MicroChannel
1786 bus while maintaining backward compatibility with cards made for
1787 the older ISA bus. The EISA bus saw limited use between 1988 and
1788 1995 when it was made obsolete by the PCI bus.
1790 Say Y here if you are building a kernel for an EISA-based machine.
1794 source "drivers/eisa/Kconfig"
1797 bool "MCA support" if !X86_VOYAGER
1798 default y if X86_VOYAGER
1800 MicroChannel Architecture is found in some IBM PS/2 machines and
1801 laptops. It is a bus system similar to PCI or ISA. See
1802 <file:Documentation/mca.txt> (and especially the web page given
1803 there) before attempting to build an MCA bus kernel.
1805 source "drivers/mca/Kconfig"
1808 tristate "NatSemi SCx200 support"
1809 depends on !X86_VOYAGER
1811 This provides basic support for National Semiconductor's
1812 (now AMD's) Geode processors. The driver probes for the
1813 PCI-IDs of several on-chip devices, so its a good dependency
1814 for other scx200_* drivers.
1816 If compiled as a module, the driver is named scx200.
1818 config SCx200HR_TIMER
1819 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1820 depends on SCx200 && GENERIC_TIME
1823 This driver provides a clocksource built upon the on-chip
1824 27MHz high-resolution timer. Its also a workaround for
1825 NSC Geode SC-1100's buggy TSC, which loses time when the
1826 processor goes idle (as is done by the scheduler). The
1827 other workaround is idle=poll boot option.
1829 config GEODE_MFGPT_TIMER
1831 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1832 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1834 This driver provides a clock event source based on the MFGPT
1835 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1836 MFGPTs have a better resolution and max interval than the
1837 generic PIT, and are suitable for use as high-res timers.
1840 bool "One Laptop Per Child support"
1843 Add support for detecting the unique features of the OLPC
1850 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1852 source "drivers/pcmcia/Kconfig"
1854 source "drivers/pci/hotplug/Kconfig"
1859 menu "Executable file formats / Emulations"
1861 source "fs/Kconfig.binfmt"
1863 config IA32_EMULATION
1864 bool "IA32 Emulation"
1866 select COMPAT_BINFMT_ELF
1868 Include code to run 32-bit programs under a 64-bit kernel. You should
1869 likely turn this on, unless you're 100% sure that you don't have any
1870 32-bit programs left.
1873 tristate "IA32 a.out support"
1874 depends on IA32_EMULATION
1876 Support old a.out binaries in the 32bit emulation.
1880 depends on IA32_EMULATION
1882 config COMPAT_FOR_U64_ALIGNMENT
1886 config SYSVIPC_COMPAT
1888 depends on COMPAT && SYSVIPC
1893 source "net/Kconfig"
1895 source "drivers/Kconfig"
1897 source "drivers/firmware/Kconfig"
1901 source "arch/x86/Kconfig.debug"
1903 source "security/Kconfig"
1905 source "crypto/Kconfig"
1907 source "arch/x86/kvm/Kconfig"
1909 source "lib/Kconfig"
projects / linux-2.6 / blob