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
656 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
657 bool "Reroute for broken boot IRQs"
659 depends on X86_IO_APIC
661 This option enables a workaround that fixes a source of
662 spurious interrupts. This is recommended when threaded
663 interrupt handling is used on systems where the generation of
664 superfluous "boot interrupts" cannot be disabled.
666 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
667 entry in the chipset's IO-APIC is masked (as, e.g. the RT
668 kernel does during interrupt handling). On chipsets where this
669 boot IRQ generation cannot be disabled, this workaround keeps
670 the original IRQ line masked so that only the equivalent "boot
671 IRQ" is delivered to the CPUs. The workaround also tells the
672 kernel to set up the IRQ handler on the boot IRQ line. In this
673 way only one interrupt is delivered to the kernel. Otherwise
674 the spurious second interrupt may cause the kernel to bring
675 down (vital) interrupt lines.
677 Only affects "broken" chipsets. Interrupt sharing may be
678 increased on these systems.
681 bool "Machine Check Exception"
682 depends on !X86_VOYAGER
684 Machine Check Exception support allows the processor to notify the
685 kernel if it detects a problem (e.g. overheating, component failure).
686 The action the kernel takes depends on the severity of the problem,
687 ranging from a warning message on the console, to halting the machine.
688 Your processor must be a Pentium or newer to support this - check the
689 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
690 have a design flaw which leads to false MCE events - hence MCE is
691 disabled on all P5 processors, unless explicitly enabled with "mce"
692 as a boot argument. Similarly, if MCE is built in and creates a
693 problem on some new non-standard machine, you can boot with "nomce"
694 to disable it. MCE support simply ignores non-MCE processors like
695 the 386 and 486, so nearly everyone can say Y here.
699 prompt "Intel MCE features"
700 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
702 Additional support for intel specific MCE features such as
707 prompt "AMD MCE features"
708 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
710 Additional support for AMD specific MCE features such as
711 the DRAM Error Threshold.
713 config X86_MCE_NONFATAL
714 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
715 depends on X86_32 && X86_MCE
717 Enabling this feature starts a timer that triggers every 5 seconds which
718 will look at the machine check registers to see if anything happened.
719 Non-fatal problems automatically get corrected (but still logged).
720 Disable this if you don't want to see these messages.
721 Seeing the messages this option prints out may be indicative of dying
722 or out-of-spec (ie, overclocked) hardware.
723 This option only does something on certain CPUs.
724 (AMD Athlon/Duron and Intel Pentium 4)
726 config X86_MCE_P4THERMAL
727 bool "check for P4 thermal throttling interrupt."
728 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
730 Enabling this feature will cause a message to be printed when the P4
731 enters thermal throttling.
734 bool "Enable VM86 support" if EMBEDDED
738 This option is required by programs like DOSEMU to run 16-bit legacy
739 code on X86 processors. It also may be needed by software like
740 XFree86 to initialize some video cards via BIOS. Disabling this
741 option saves about 6k.
744 tristate "Toshiba Laptop support"
747 This adds a driver to safely access the System Management Mode of
748 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
749 not work on models with a Phoenix BIOS. The System Management Mode
750 is used to set the BIOS and power saving options on Toshiba portables.
752 For information on utilities to make use of this driver see the
753 Toshiba Linux utilities web site at:
754 <http://www.buzzard.org.uk/toshiba/>.
756 Say Y if you intend to run this kernel on a Toshiba portable.
760 tristate "Dell laptop support"
762 This adds a driver to safely access the System Management Mode
763 of the CPU on the Dell Inspiron 8000. The System Management Mode
764 is used to read cpu temperature and cooling fan status and to
765 control the fans on the I8K portables.
767 This driver has been tested only on the Inspiron 8000 but it may
768 also work with other Dell laptops. You can force loading on other
769 models by passing the parameter `force=1' to the module. Use at
772 For information on utilities to make use of this driver see the
773 I8K Linux utilities web site at:
774 <http://people.debian.org/~dz/i8k/>
776 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
779 config X86_REBOOTFIXUPS
780 bool "Enable X86 board specific fixups for reboot"
783 This enables chipset and/or board specific fixups to be done
784 in order to get reboot to work correctly. This is only needed on
785 some combinations of hardware and BIOS. The symptom, for which
786 this config is intended, is when reboot ends with a stalled/hung
789 Currently, the only fixup is for the Geode machines using
790 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
792 Say Y if you want to enable the fixup. Currently, it's safe to
793 enable this option even if you don't need it.
797 tristate "/dev/cpu/microcode - microcode support"
800 If you say Y here, you will be able to update the microcode on
801 certain Intel and AMD processors. The Intel support is for the
802 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
803 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
804 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
805 You will obviously need the actual microcode binary data itself
806 which is not shipped with the Linux kernel.
808 This option selects the general module only, you need to select
809 at least one vendor specific module as well.
811 To compile this driver as a module, choose M here: the
812 module will be called microcode.
814 config MICROCODE_INTEL
815 bool "Intel microcode patch loading support"
820 This options enables microcode patch loading support for Intel
823 For latest news and information on obtaining all the required
824 Intel ingredients for this driver, check:
825 <http://www.urbanmyth.org/microcode/>.
828 bool "AMD microcode patch loading support"
832 If you select this option, microcode patch loading support for AMD
833 processors will be enabled.
835 config MICROCODE_OLD_INTERFACE
840 tristate "/dev/cpu/*/msr - Model-specific register support"
842 This device gives privileged processes access to the x86
843 Model-Specific Registers (MSRs). It is a character device with
844 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
845 MSR accesses are directed to a specific CPU on multi-processor
849 tristate "/dev/cpu/*/cpuid - CPU information support"
851 This device gives processes access to the x86 CPUID instruction to
852 be executed on a specific processor. It is a character device
853 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
857 prompt "High Memory Support"
858 default HIGHMEM4G if !X86_NUMAQ
859 default HIGHMEM64G if X86_NUMAQ
864 depends on !X86_NUMAQ
866 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
867 However, the address space of 32-bit x86 processors is only 4
868 Gigabytes large. That means that, if you have a large amount of
869 physical memory, not all of it can be "permanently mapped" by the
870 kernel. The physical memory that's not permanently mapped is called
873 If you are compiling a kernel which will never run on a machine with
874 more than 1 Gigabyte total physical RAM, answer "off" here (default
875 choice and suitable for most users). This will result in a "3GB/1GB"
876 split: 3GB are mapped so that each process sees a 3GB virtual memory
877 space and the remaining part of the 4GB virtual memory space is used
878 by the kernel to permanently map as much physical memory as
881 If the machine has between 1 and 4 Gigabytes physical RAM, then
884 If more than 4 Gigabytes is used then answer "64GB" here. This
885 selection turns Intel PAE (Physical Address Extension) mode on.
886 PAE implements 3-level paging on IA32 processors. PAE is fully
887 supported by Linux, PAE mode is implemented on all recent Intel
888 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
889 then the kernel will not boot on CPUs that don't support PAE!
891 The actual amount of total physical memory will either be
892 auto detected or can be forced by using a kernel command line option
893 such as "mem=256M". (Try "man bootparam" or see the documentation of
894 your boot loader (lilo or loadlin) about how to pass options to the
895 kernel at boot time.)
897 If unsure, say "off".
901 depends on !X86_NUMAQ
903 Select this if you have a 32-bit processor and between 1 and 4
904 gigabytes of physical RAM.
908 depends on !M386 && !M486
911 Select this if you have a 32-bit processor and more than 4
912 gigabytes of physical RAM.
917 depends on EXPERIMENTAL
918 prompt "Memory split" if EMBEDDED
922 Select the desired split between kernel and user memory.
924 If the address range available to the kernel is less than the
925 physical memory installed, the remaining memory will be available
926 as "high memory". Accessing high memory is a little more costly
927 than low memory, as it needs to be mapped into the kernel first.
928 Note that increasing the kernel address space limits the range
929 available to user programs, making the address space there
930 tighter. Selecting anything other than the default 3G/1G split
931 will also likely make your kernel incompatible with binary-only
934 If you are not absolutely sure what you are doing, leave this
938 bool "3G/1G user/kernel split"
939 config VMSPLIT_3G_OPT
941 bool "3G/1G user/kernel split (for full 1G low memory)"
943 bool "2G/2G user/kernel split"
944 config VMSPLIT_2G_OPT
946 bool "2G/2G user/kernel split (for full 2G low memory)"
948 bool "1G/3G user/kernel split"
953 default 0xB0000000 if VMSPLIT_3G_OPT
954 default 0x80000000 if VMSPLIT_2G
955 default 0x78000000 if VMSPLIT_2G_OPT
956 default 0x40000000 if VMSPLIT_1G
962 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
965 bool "PAE (Physical Address Extension) Support"
966 depends on X86_32 && !HIGHMEM4G
968 PAE is required for NX support, and furthermore enables
969 larger swapspace support for non-overcommit purposes. It
970 has the cost of more pagetable lookup overhead, and also
971 consumes more pagetable space per process.
973 config ARCH_PHYS_ADDR_T_64BIT
974 def_bool X86_64 || X86_PAE
976 # Common NUMA Features
978 bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
980 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
982 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
984 Enable NUMA (Non Uniform Memory Access) support.
985 The kernel will try to allocate memory used by a CPU on the
986 local memory controller of the CPU and add some more
987 NUMA awareness to the kernel.
989 For 32-bit this is currently highly experimental and should be only
990 used for kernel development. It might also cause boot failures.
991 For 64-bit this is recommended on all multiprocessor Opteron systems.
992 If the system is EM64T, you should say N unless your system is
995 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
996 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1000 prompt "Old style AMD Opteron NUMA detection"
1001 depends on X86_64 && NUMA && PCI
1003 Enable K8 NUMA node topology detection. You should say Y here if
1004 you have a multi processor AMD K8 system. This uses an old
1005 method to read the NUMA configuration directly from the builtin
1006 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1007 instead, which also takes priority if both are compiled in.
1009 config X86_64_ACPI_NUMA
1011 prompt "ACPI NUMA detection"
1012 depends on X86_64 && NUMA && ACPI && PCI
1015 Enable ACPI SRAT based node topology detection.
1017 # Some NUMA nodes have memory ranges that span
1018 # other nodes. Even though a pfn is valid and
1019 # between a node's start and end pfns, it may not
1020 # reside on that node. See memmap_init_zone()
1022 config NODES_SPAN_OTHER_NODES
1024 depends on X86_64_ACPI_NUMA
1027 bool "NUMA emulation"
1028 depends on X86_64 && NUMA
1030 Enable NUMA emulation. A flat machine will be split
1031 into virtual nodes when booted with "numa=fake=N", where N is the
1032 number of nodes. This is only useful for debugging.
1035 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1037 default "9" if MAXSMP
1038 default "6" if X86_64
1039 default "4" if X86_NUMAQ
1041 depends on NEED_MULTIPLE_NODES
1043 Specify the maximum number of NUMA Nodes available on the target
1044 system. Increases memory reserved to accomodate various tables.
1046 config HAVE_ARCH_BOOTMEM_NODE
1048 depends on X86_32 && NUMA
1050 config ARCH_HAVE_MEMORY_PRESENT
1052 depends on X86_32 && DISCONTIGMEM
1054 config NEED_NODE_MEMMAP_SIZE
1056 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1058 config HAVE_ARCH_ALLOC_REMAP
1060 depends on X86_32 && NUMA
1062 config ARCH_FLATMEM_ENABLE
1064 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1066 config ARCH_DISCONTIGMEM_ENABLE
1068 depends on NUMA && X86_32
1070 config ARCH_DISCONTIGMEM_DEFAULT
1072 depends on NUMA && X86_32
1074 config ARCH_SPARSEMEM_DEFAULT
1078 config ARCH_SPARSEMEM_ENABLE
1080 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH
1081 select SPARSEMEM_STATIC if X86_32
1082 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1084 config ARCH_SELECT_MEMORY_MODEL
1086 depends on ARCH_SPARSEMEM_ENABLE
1088 config ARCH_MEMORY_PROBE
1090 depends on MEMORY_HOTPLUG
1095 bool "Allocate 3rd-level pagetables from highmem"
1096 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1098 The VM uses one page table entry for each page of physical memory.
1099 For systems with a lot of RAM, this can be wasteful of precious
1100 low memory. Setting this option will put user-space page table
1101 entries in high memory.
1103 config X86_CHECK_BIOS_CORRUPTION
1104 bool "Check for low memory corruption"
1106 Periodically check for memory corruption in low memory, which
1107 is suspected to be caused by BIOS. Even when enabled in the
1108 configuration, it is disabled at runtime. Enable it by
1109 setting "memory_corruption_check=1" on the kernel command
1110 line. By default it scans the low 64k of memory every 60
1111 seconds; see the memory_corruption_check_size and
1112 memory_corruption_check_period parameters in
1113 Documentation/kernel-parameters.txt to adjust this.
1115 When enabled with the default parameters, this option has
1116 almost no overhead, as it reserves a relatively small amount
1117 of memory and scans it infrequently. It both detects corruption
1118 and prevents it from affecting the running system.
1120 It is, however, intended as a diagnostic tool; if repeatable
1121 BIOS-originated corruption always affects the same memory,
1122 you can use memmap= to prevent the kernel from using that
1125 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1126 bool "Set the default setting of memory_corruption_check"
1127 depends on X86_CHECK_BIOS_CORRUPTION
1130 Set whether the default state of memory_corruption_check is
1133 config X86_RESERVE_LOW_64K
1134 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1137 Reserve the first 64K of physical RAM on BIOSes that are known
1138 to potentially corrupt that memory range. A numbers of BIOSes are
1139 known to utilize this area during suspend/resume, so it must not
1140 be used by the kernel.
1142 Set this to N if you are absolutely sure that you trust the BIOS
1143 to get all its memory reservations and usages right.
1145 If you have doubts about the BIOS (e.g. suspend/resume does not
1146 work or there's kernel crashes after certain hardware hotplug
1147 events) and it's not AMI or Phoenix, then you might want to enable
1148 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1149 corruption patterns.
1153 config MATH_EMULATION
1155 prompt "Math emulation" if X86_32
1157 Linux can emulate a math coprocessor (used for floating point
1158 operations) if you don't have one. 486DX and Pentium processors have
1159 a math coprocessor built in, 486SX and 386 do not, unless you added
1160 a 487DX or 387, respectively. (The messages during boot time can
1161 give you some hints here ["man dmesg"].) Everyone needs either a
1162 coprocessor or this emulation.
1164 If you don't have a math coprocessor, you need to say Y here; if you
1165 say Y here even though you have a coprocessor, the coprocessor will
1166 be used nevertheless. (This behavior can be changed with the kernel
1167 command line option "no387", which comes handy if your coprocessor
1168 is broken. Try "man bootparam" or see the documentation of your boot
1169 loader (lilo or loadlin) about how to pass options to the kernel at
1170 boot time.) This means that it is a good idea to say Y here if you
1171 intend to use this kernel on different machines.
1173 More information about the internals of the Linux math coprocessor
1174 emulation can be found in <file:arch/x86/math-emu/README>.
1176 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1177 kernel, it won't hurt.
1180 bool "MTRR (Memory Type Range Register) support"
1182 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1183 the Memory Type Range Registers (MTRRs) may be used to control
1184 processor access to memory ranges. This is most useful if you have
1185 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1186 allows bus write transfers to be combined into a larger transfer
1187 before bursting over the PCI/AGP bus. This can increase performance
1188 of image write operations 2.5 times or more. Saying Y here creates a
1189 /proc/mtrr file which may be used to manipulate your processor's
1190 MTRRs. Typically the X server should use this.
1192 This code has a reasonably generic interface so that similar
1193 control registers on other processors can be easily supported
1196 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1197 Registers (ARRs) which provide a similar functionality to MTRRs. For
1198 these, the ARRs are used to emulate the MTRRs.
1199 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1200 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1201 write-combining. All of these processors are supported by this code
1202 and it makes sense to say Y here if you have one of them.
1204 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1205 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1206 can lead to all sorts of problems, so it's good to say Y here.
1208 You can safely say Y even if your machine doesn't have MTRRs, you'll
1209 just add about 9 KB to your kernel.
1211 See <file:Documentation/x86/mtrr.txt> for more information.
1213 config MTRR_SANITIZER
1215 prompt "MTRR cleanup support"
1218 Convert MTRR layout from continuous to discrete, so X drivers can
1219 add writeback entries.
1221 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1222 The largest mtrr entry size for a continous block can be set with
1227 config MTRR_SANITIZER_ENABLE_DEFAULT
1228 int "MTRR cleanup enable value (0-1)"
1231 depends on MTRR_SANITIZER
1233 Enable mtrr cleanup default value
1235 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1236 int "MTRR cleanup spare reg num (0-7)"
1239 depends on MTRR_SANITIZER
1241 mtrr cleanup spare entries default, it can be changed via
1242 mtrr_spare_reg_nr=N on the kernel command line.
1246 prompt "x86 PAT support"
1249 Use PAT attributes to setup page level cache control.
1251 PATs are the modern equivalents of MTRRs and are much more
1252 flexible than MTRRs.
1254 Say N here if you see bootup problems (boot crash, boot hang,
1255 spontaneous reboots) or a non-working video driver.
1260 bool "EFI runtime service support"
1263 This enables the kernel to use EFI runtime services that are
1264 available (such as the EFI variable services).
1266 This option is only useful on systems that have EFI firmware.
1267 In addition, you should use the latest ELILO loader available
1268 at <http://elilo.sourceforge.net> in order to take advantage
1269 of EFI runtime services. However, even with this option, the
1270 resultant kernel should continue to boot on existing non-EFI
1275 prompt "Enable seccomp to safely compute untrusted bytecode"
1277 This kernel feature is useful for number crunching applications
1278 that may need to compute untrusted bytecode during their
1279 execution. By using pipes or other transports made available to
1280 the process as file descriptors supporting the read/write
1281 syscalls, it's possible to isolate those applications in
1282 their own address space using seccomp. Once seccomp is
1283 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1284 and the task is only allowed to execute a few safe syscalls
1285 defined by each seccomp mode.
1287 If unsure, say Y. Only embedded should say N here.
1289 config CC_STACKPROTECTOR
1290 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1291 depends on X86_64 && EXPERIMENTAL && BROKEN
1293 This option turns on the -fstack-protector GCC feature. This
1294 feature puts, at the beginning of critical functions, a canary
1295 value on the stack just before the return address, and validates
1296 the value just before actually returning. Stack based buffer
1297 overflows (that need to overwrite this return address) now also
1298 overwrite the canary, which gets detected and the attack is then
1299 neutralized via a kernel panic.
1301 This feature requires gcc version 4.2 or above, or a distribution
1302 gcc with the feature backported. Older versions are automatically
1303 detected and for those versions, this configuration option is ignored.
1305 config CC_STACKPROTECTOR_ALL
1306 bool "Use stack-protector for all functions"
1307 depends on CC_STACKPROTECTOR
1309 Normally, GCC only inserts the canary value protection for
1310 functions that use large-ish on-stack buffers. By enabling
1311 this option, GCC will be asked to do this for ALL functions.
1313 source kernel/Kconfig.hz
1316 bool "kexec system call"
1317 depends on X86_BIOS_REBOOT
1319 kexec is a system call that implements the ability to shutdown your
1320 current kernel, and to start another kernel. It is like a reboot
1321 but it is independent of the system firmware. And like a reboot
1322 you can start any kernel with it, not just Linux.
1324 The name comes from the similarity to the exec system call.
1326 It is an ongoing process to be certain the hardware in a machine
1327 is properly shutdown, so do not be surprised if this code does not
1328 initially work for you. It may help to enable device hotplugging
1329 support. As of this writing the exact hardware interface is
1330 strongly in flux, so no good recommendation can be made.
1333 bool "kernel crash dumps"
1334 depends on X86_64 || (X86_32 && HIGHMEM)
1336 Generate crash dump after being started by kexec.
1337 This should be normally only set in special crash dump kernels
1338 which are loaded in the main kernel with kexec-tools into
1339 a specially reserved region and then later executed after
1340 a crash by kdump/kexec. The crash dump kernel must be compiled
1341 to a memory address not used by the main kernel or BIOS using
1342 PHYSICAL_START, or it must be built as a relocatable image
1343 (CONFIG_RELOCATABLE=y).
1344 For more details see Documentation/kdump/kdump.txt
1347 bool "kexec jump (EXPERIMENTAL)"
1348 depends on EXPERIMENTAL
1349 depends on KEXEC && HIBERNATION && X86_32
1351 Jump between original kernel and kexeced kernel and invoke
1352 code in physical address mode via KEXEC
1354 config PHYSICAL_START
1355 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1356 default "0x1000000" if X86_NUMAQ
1357 default "0x200000" if X86_64
1360 This gives the physical address where the kernel is loaded.
1362 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1363 bzImage will decompress itself to above physical address and
1364 run from there. Otherwise, bzImage will run from the address where
1365 it has been loaded by the boot loader and will ignore above physical
1368 In normal kdump cases one does not have to set/change this option
1369 as now bzImage can be compiled as a completely relocatable image
1370 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1371 address. This option is mainly useful for the folks who don't want
1372 to use a bzImage for capturing the crash dump and want to use a
1373 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1374 to be specifically compiled to run from a specific memory area
1375 (normally a reserved region) and this option comes handy.
1377 So if you are using bzImage for capturing the crash dump, leave
1378 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1379 Otherwise if you plan to use vmlinux for capturing the crash dump
1380 change this value to start of the reserved region (Typically 16MB
1381 0x1000000). In other words, it can be set based on the "X" value as
1382 specified in the "crashkernel=YM@XM" command line boot parameter
1383 passed to the panic-ed kernel. Typically this parameter is set as
1384 crashkernel=64M@16M. Please take a look at
1385 Documentation/kdump/kdump.txt for more details about crash dumps.
1387 Usage of bzImage for capturing the crash dump is recommended as
1388 one does not have to build two kernels. Same kernel can be used
1389 as production kernel and capture kernel. Above option should have
1390 gone away after relocatable bzImage support is introduced. But it
1391 is present because there are users out there who continue to use
1392 vmlinux for dump capture. This option should go away down the
1395 Don't change this unless you know what you are doing.
1398 bool "Build a relocatable kernel (EXPERIMENTAL)"
1399 depends on EXPERIMENTAL
1401 This builds a kernel image that retains relocation information
1402 so it can be loaded someplace besides the default 1MB.
1403 The relocations tend to make the kernel binary about 10% larger,
1404 but are discarded at runtime.
1406 One use is for the kexec on panic case where the recovery kernel
1407 must live at a different physical address than the primary
1410 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1411 it has been loaded at and the compile time physical address
1412 (CONFIG_PHYSICAL_START) is ignored.
1414 config PHYSICAL_ALIGN
1416 prompt "Alignment value to which kernel should be aligned" if X86_32
1417 default "0x100000" if X86_32
1418 default "0x200000" if X86_64
1419 range 0x2000 0x400000
1421 This value puts the alignment restrictions on physical address
1422 where kernel is loaded and run from. Kernel is compiled for an
1423 address which meets above alignment restriction.
1425 If bootloader loads the kernel at a non-aligned address and
1426 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1427 address aligned to above value and run from there.
1429 If bootloader loads the kernel at a non-aligned address and
1430 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1431 load address and decompress itself to the address it has been
1432 compiled for and run from there. The address for which kernel is
1433 compiled already meets above alignment restrictions. Hence the
1434 end result is that kernel runs from a physical address meeting
1435 above alignment restrictions.
1437 Don't change this unless you know what you are doing.
1440 bool "Support for hot-pluggable CPUs"
1441 depends on SMP && HOTPLUG && !X86_VOYAGER
1443 Say Y here to allow turning CPUs off and on. CPUs can be
1444 controlled through /sys/devices/system/cpu.
1445 ( Note: power management support will enable this option
1446 automatically on SMP systems. )
1447 Say N if you want to disable CPU hotplug.
1451 prompt "Compat VDSO support"
1452 depends on X86_32 || IA32_EMULATION
1454 Map the 32-bit VDSO to the predictable old-style address too.
1456 Say N here if you are running a sufficiently recent glibc
1457 version (2.3.3 or later), to remove the high-mapped
1458 VDSO mapping and to exclusively use the randomized VDSO.
1463 bool "Built-in kernel command line"
1466 Allow for specifying boot arguments to the kernel at
1467 build time. On some systems (e.g. embedded ones), it is
1468 necessary or convenient to provide some or all of the
1469 kernel boot arguments with the kernel itself (that is,
1470 to not rely on the boot loader to provide them.)
1472 To compile command line arguments into the kernel,
1473 set this option to 'Y', then fill in the
1474 the boot arguments in CONFIG_CMDLINE.
1476 Systems with fully functional boot loaders (i.e. non-embedded)
1477 should leave this option set to 'N'.
1480 string "Built-in kernel command string"
1481 depends on CMDLINE_BOOL
1484 Enter arguments here that should be compiled into the kernel
1485 image and used at boot time. If the boot loader provides a
1486 command line at boot time, it is appended to this string to
1487 form the full kernel command line, when the system boots.
1489 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1490 change this behavior.
1492 In most cases, the command line (whether built-in or provided
1493 by the boot loader) should specify the device for the root
1496 config CMDLINE_OVERRIDE
1497 bool "Built-in command line overrides boot loader arguments"
1499 depends on CMDLINE_BOOL
1501 Set this option to 'Y' to have the kernel ignore the boot loader
1502 command line, and use ONLY the built-in command line.
1504 This is used to work around broken boot loaders. This should
1505 be set to 'N' under normal conditions.
1509 config ARCH_ENABLE_MEMORY_HOTPLUG
1511 depends on X86_64 || (X86_32 && HIGHMEM)
1513 config HAVE_ARCH_EARLY_PFN_TO_NID
1517 menu "Power management options"
1518 depends on !X86_VOYAGER
1520 config ARCH_HIBERNATION_HEADER
1522 depends on X86_64 && HIBERNATION
1524 source "kernel/power/Kconfig"
1526 source "drivers/acpi/Kconfig"
1531 depends on APM || APM_MODULE
1534 tristate "APM (Advanced Power Management) BIOS support"
1535 depends on X86_32 && PM_SLEEP
1537 APM is a BIOS specification for saving power using several different
1538 techniques. This is mostly useful for battery powered laptops with
1539 APM compliant BIOSes. If you say Y here, the system time will be
1540 reset after a RESUME operation, the /proc/apm device will provide
1541 battery status information, and user-space programs will receive
1542 notification of APM "events" (e.g. battery status change).
1544 If you select "Y" here, you can disable actual use of the APM
1545 BIOS by passing the "apm=off" option to the kernel at boot time.
1547 Note that the APM support is almost completely disabled for
1548 machines with more than one CPU.
1550 In order to use APM, you will need supporting software. For location
1551 and more information, read <file:Documentation/power/pm.txt> and the
1552 Battery Powered Linux mini-HOWTO, available from
1553 <http://www.tldp.org/docs.html#howto>.
1555 This driver does not spin down disk drives (see the hdparm(8)
1556 manpage ("man 8 hdparm") for that), and it doesn't turn off
1557 VESA-compliant "green" monitors.
1559 This driver does not support the TI 4000M TravelMate and the ACER
1560 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1561 desktop machines also don't have compliant BIOSes, and this driver
1562 may cause those machines to panic during the boot phase.
1564 Generally, if you don't have a battery in your machine, there isn't
1565 much point in using this driver and you should say N. If you get
1566 random kernel OOPSes or reboots that don't seem to be related to
1567 anything, try disabling/enabling this option (or disabling/enabling
1570 Some other things you should try when experiencing seemingly random,
1573 1) make sure that you have enough swap space and that it is
1575 2) pass the "no-hlt" option to the kernel
1576 3) switch on floating point emulation in the kernel and pass
1577 the "no387" option to the kernel
1578 4) pass the "floppy=nodma" option to the kernel
1579 5) pass the "mem=4M" option to the kernel (thereby disabling
1580 all but the first 4 MB of RAM)
1581 6) make sure that the CPU is not over clocked.
1582 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1583 8) disable the cache from your BIOS settings
1584 9) install a fan for the video card or exchange video RAM
1585 10) install a better fan for the CPU
1586 11) exchange RAM chips
1587 12) exchange the motherboard.
1589 To compile this driver as a module, choose M here: the
1590 module will be called apm.
1594 config APM_IGNORE_USER_SUSPEND
1595 bool "Ignore USER SUSPEND"
1597 This option will ignore USER SUSPEND requests. On machines with a
1598 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1599 series notebooks, it is necessary to say Y because of a BIOS bug.
1601 config APM_DO_ENABLE
1602 bool "Enable PM at boot time"
1604 Enable APM features at boot time. From page 36 of the APM BIOS
1605 specification: "When disabled, the APM BIOS does not automatically
1606 power manage devices, enter the Standby State, enter the Suspend
1607 State, or take power saving steps in response to CPU Idle calls."
1608 This driver will make CPU Idle calls when Linux is idle (unless this
1609 feature is turned off -- see "Do CPU IDLE calls", below). This
1610 should always save battery power, but more complicated APM features
1611 will be dependent on your BIOS implementation. You may need to turn
1612 this option off if your computer hangs at boot time when using APM
1613 support, or if it beeps continuously instead of suspending. Turn
1614 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1615 T400CDT. This is off by default since most machines do fine without
1619 bool "Make CPU Idle calls when idle"
1621 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1622 On some machines, this can activate improved power savings, such as
1623 a slowed CPU clock rate, when the machine is idle. These idle calls
1624 are made after the idle loop has run for some length of time (e.g.,
1625 333 mS). On some machines, this will cause a hang at boot time or
1626 whenever the CPU becomes idle. (On machines with more than one CPU,
1627 this option does nothing.)
1629 config APM_DISPLAY_BLANK
1630 bool "Enable console blanking using APM"
1632 Enable console blanking using the APM. Some laptops can use this to
1633 turn off the LCD backlight when the screen blanker of the Linux
1634 virtual console blanks the screen. Note that this is only used by
1635 the virtual console screen blanker, and won't turn off the backlight
1636 when using the X Window system. This also doesn't have anything to
1637 do with your VESA-compliant power-saving monitor. Further, this
1638 option doesn't work for all laptops -- it might not turn off your
1639 backlight at all, or it might print a lot of errors to the console,
1640 especially if you are using gpm.
1642 config APM_ALLOW_INTS
1643 bool "Allow interrupts during APM BIOS calls"
1645 Normally we disable external interrupts while we are making calls to
1646 the APM BIOS as a measure to lessen the effects of a badly behaving
1647 BIOS implementation. The BIOS should reenable interrupts if it
1648 needs to. Unfortunately, some BIOSes do not -- especially those in
1649 many of the newer IBM Thinkpads. If you experience hangs when you
1650 suspend, try setting this to Y. Otherwise, say N.
1652 config APM_REAL_MODE_POWER_OFF
1653 bool "Use real mode APM BIOS call to power off"
1655 Use real mode APM BIOS calls to switch off the computer. This is
1656 a work-around for a number of buggy BIOSes. Switch this option on if
1657 your computer crashes instead of powering off properly.
1661 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1663 source "drivers/cpuidle/Kconfig"
1665 source "drivers/idle/Kconfig"
1670 menu "Bus options (PCI etc.)"
1675 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1677 Find out whether you have a PCI motherboard. PCI is the name of a
1678 bus system, i.e. the way the CPU talks to the other stuff inside
1679 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1680 VESA. If you have PCI, say Y, otherwise N.
1683 prompt "PCI access mode"
1684 depends on X86_32 && PCI
1687 On PCI systems, the BIOS can be used to detect the PCI devices and
1688 determine their configuration. However, some old PCI motherboards
1689 have BIOS bugs and may crash if this is done. Also, some embedded
1690 PCI-based systems don't have any BIOS at all. Linux can also try to
1691 detect the PCI hardware directly without using the BIOS.
1693 With this option, you can specify how Linux should detect the
1694 PCI devices. If you choose "BIOS", the BIOS will be used,
1695 if you choose "Direct", the BIOS won't be used, and if you
1696 choose "MMConfig", then PCI Express MMCONFIG will be used.
1697 If you choose "Any", the kernel will try MMCONFIG, then the
1698 direct access method and falls back to the BIOS if that doesn't
1699 work. If unsure, go with the default, which is "Any".
1704 config PCI_GOMMCONFIG
1721 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1723 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1726 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1730 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1734 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1741 bool "Support mmconfig PCI config space access"
1742 depends on X86_64 && PCI && ACPI
1745 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1746 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1748 DMA remapping (DMAR) devices support enables independent address
1749 translations for Direct Memory Access (DMA) from devices.
1750 These DMA remapping devices are reported via ACPI tables
1751 and include PCI device scope covered by these DMA
1756 prompt "Support for Graphics workaround"
1759 Current Graphics drivers tend to use physical address
1760 for DMA and avoid using DMA APIs. Setting this config
1761 option permits the IOMMU driver to set a unity map for
1762 all the OS-visible memory. Hence the driver can continue
1763 to use physical addresses for DMA.
1765 config DMAR_FLOPPY_WA
1769 Floppy disk drivers are know to bypass DMA API calls
1770 thereby failing to work when IOMMU is enabled. This
1771 workaround will setup a 1:1 mapping for the first
1772 16M to make floppy (an ISA device) work.
1775 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1776 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1778 Supports Interrupt remapping for IO-APIC and MSI devices.
1779 To use x2apic mode in the CPU's which support x2APIC enhancements or
1780 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1782 source "drivers/pci/pcie/Kconfig"
1784 source "drivers/pci/Kconfig"
1786 # x86_64 have no ISA slots, but do have ISA-style DMA.
1794 depends on !X86_VOYAGER
1796 Find out whether you have ISA slots on your motherboard. ISA is the
1797 name of a bus system, i.e. the way the CPU talks to the other stuff
1798 inside your box. Other bus systems are PCI, EISA, MicroChannel
1799 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1800 newer boards don't support it. If you have ISA, say Y, otherwise N.
1806 The Extended Industry Standard Architecture (EISA) bus was
1807 developed as an open alternative to the IBM MicroChannel bus.
1809 The EISA bus provided some of the features of the IBM MicroChannel
1810 bus while maintaining backward compatibility with cards made for
1811 the older ISA bus. The EISA bus saw limited use between 1988 and
1812 1995 when it was made obsolete by the PCI bus.
1814 Say Y here if you are building a kernel for an EISA-based machine.
1818 source "drivers/eisa/Kconfig"
1821 bool "MCA support" if !X86_VOYAGER
1822 default y if X86_VOYAGER
1824 MicroChannel Architecture is found in some IBM PS/2 machines and
1825 laptops. It is a bus system similar to PCI or ISA. See
1826 <file:Documentation/mca.txt> (and especially the web page given
1827 there) before attempting to build an MCA bus kernel.
1829 source "drivers/mca/Kconfig"
1832 tristate "NatSemi SCx200 support"
1833 depends on !X86_VOYAGER
1835 This provides basic support for National Semiconductor's
1836 (now AMD's) Geode processors. The driver probes for the
1837 PCI-IDs of several on-chip devices, so its a good dependency
1838 for other scx200_* drivers.
1840 If compiled as a module, the driver is named scx200.
1842 config SCx200HR_TIMER
1843 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1844 depends on SCx200 && GENERIC_TIME
1847 This driver provides a clocksource built upon the on-chip
1848 27MHz high-resolution timer. Its also a workaround for
1849 NSC Geode SC-1100's buggy TSC, which loses time when the
1850 processor goes idle (as is done by the scheduler). The
1851 other workaround is idle=poll boot option.
1853 config GEODE_MFGPT_TIMER
1855 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1856 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1858 This driver provides a clock event source based on the MFGPT
1859 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1860 MFGPTs have a better resolution and max interval than the
1861 generic PIT, and are suitable for use as high-res timers.
1864 bool "One Laptop Per Child support"
1867 Add support for detecting the unique features of the OLPC
1874 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1876 source "drivers/pcmcia/Kconfig"
1878 source "drivers/pci/hotplug/Kconfig"
1883 menu "Executable file formats / Emulations"
1885 source "fs/Kconfig.binfmt"
1887 config IA32_EMULATION
1888 bool "IA32 Emulation"
1890 select COMPAT_BINFMT_ELF
1892 Include code to run 32-bit programs under a 64-bit kernel. You should
1893 likely turn this on, unless you're 100% sure that you don't have any
1894 32-bit programs left.
1897 tristate "IA32 a.out support"
1898 depends on IA32_EMULATION
1900 Support old a.out binaries in the 32bit emulation.
1904 depends on IA32_EMULATION
1906 config COMPAT_FOR_U64_ALIGNMENT
1910 config SYSVIPC_COMPAT
1912 depends on COMPAT && SYSVIPC
1917 source "net/Kconfig"
1919 source "drivers/Kconfig"
1921 source "drivers/firmware/Kconfig"
1925 source "arch/x86/Kconfig.debug"
1927 source "security/Kconfig"
1929 source "crypto/Kconfig"
1931 source "arch/x86/kvm/Kconfig"
1933 source "lib/Kconfig"
git.openpandora.org / pandora-kernel.git / blob