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
24 select HAVE_UNSTABLE_SCHED_CLOCK
27 select HAVE_IOREMAP_PROT
29 select ARCH_WANT_OPTIONAL_GPIOLIB
30 select ARCH_WANT_FRAME_POINTERS
31 select HAVE_KRETPROBES
32 select HAVE_FTRACE_MCOUNT_RECORD
33 select HAVE_DYNAMIC_FTRACE
34 select HAVE_FUNCTION_TRACER
35 select HAVE_FUNCTION_GRAPH_TRACER
36 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
37 select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
38 select HAVE_ARCH_KGDB if !X86_VOYAGER
39 select HAVE_ARCH_TRACEHOOK
40 select HAVE_GENERIC_DMA_COHERENT if X86_32
41 select HAVE_EFFICIENT_UNALIGNED_ACCESS
42 select USER_STACKTRACE_SUPPORT
46 default "arch/x86/configs/i386_defconfig" if X86_32
47 default "arch/x86/configs/x86_64_defconfig" if X86_64
52 config GENERIC_CMOS_UPDATE
55 config CLOCKSOURCE_WATCHDOG
58 config GENERIC_CLOCKEVENTS
61 config GENERIC_CLOCKEVENTS_BROADCAST
63 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
65 config LOCKDEP_SUPPORT
68 config STACKTRACE_SUPPORT
71 config HAVE_LATENCYTOP_SUPPORT
74 config FAST_CMPXCHG_LOCAL
87 config GENERIC_ISA_DMA
96 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
98 config GENERIC_BUG_RELATIVE_POINTERS
101 config GENERIC_HWEIGHT
107 config ARCH_MAY_HAVE_PC_FDC
110 config RWSEM_GENERIC_SPINLOCK
113 config RWSEM_XCHGADD_ALGORITHM
116 config ARCH_HAS_CPU_IDLE_WAIT
119 config GENERIC_CALIBRATE_DELAY
122 config GENERIC_TIME_VSYSCALL
126 config ARCH_HAS_CPU_RELAX
129 config ARCH_HAS_DEFAULT_IDLE
132 config ARCH_HAS_CACHE_LINE_SIZE
135 config HAVE_SETUP_PER_CPU_AREA
138 config HAVE_DYNAMIC_PER_CPU_AREA
141 config HAVE_CPUMASK_OF_CPU_MAP
144 config ARCH_HIBERNATION_POSSIBLE
146 depends on !SMP || !X86_VOYAGER
148 config ARCH_SUSPEND_POSSIBLE
150 depends on !X86_VOYAGER
156 config ARCH_POPULATES_NODE_MAP
163 config ARCH_SUPPORTS_OPTIMIZED_INLINING
166 # Use the generic interrupt handling code in kernel/irq/:
167 config GENERIC_HARDIRQS
171 config GENERIC_IRQ_PROBE
175 config GENERIC_PENDING_IRQ
177 depends on GENERIC_HARDIRQS && SMP
182 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
185 config USE_GENERIC_SMP_HELPERS
191 depends on X86_32 && SMP
195 depends on X86_64 && SMP
200 depends on (X86_32 && !X86_VOYAGER) || X86_64
203 config X86_BIOS_REBOOT
205 depends on !X86_VOYAGER
208 config X86_TRAMPOLINE
210 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
213 config X86_32_LAZY_GS
215 depends on X86_32 && !CC_STACKPROTECTOR
219 source "init/Kconfig"
220 source "kernel/Kconfig.freezer"
222 menu "Processor type and features"
224 source "kernel/time/Kconfig"
227 bool "Symmetric multi-processing support"
229 This enables support for systems with more than one CPU. If you have
230 a system with only one CPU, like most personal computers, say N. If
231 you have a system with more than one CPU, say Y.
233 If you say N here, the kernel will run on single and multiprocessor
234 machines, but will use only one CPU of a multiprocessor machine. If
235 you say Y here, the kernel will run on many, but not all,
236 singleprocessor machines. On a singleprocessor machine, the kernel
237 will run faster if you say N here.
239 Note that if you say Y here and choose architecture "586" or
240 "Pentium" under "Processor family", the kernel will not work on 486
241 architectures. Similarly, multiprocessor kernels for the "PPro"
242 architecture may not work on all Pentium based boards.
244 People using multiprocessor machines who say Y here should also say
245 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
246 Management" code will be disabled if you say Y here.
248 See also <file:Documentation/i386/IO-APIC.txt>,
249 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
250 <http://www.tldp.org/docs.html#howto>.
252 If you don't know what to do here, say N.
254 config X86_HAS_BOOT_CPU_ID
256 depends on X86_VOYAGER
259 bool "Support sparse irq numbering"
260 depends on PCI_MSI || HT_IRQ
262 This enables support for sparse irqs. This is useful for distro
263 kernels that want to define a high CONFIG_NR_CPUS value but still
264 want to have low kernel memory footprint on smaller machines.
266 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
267 out the irq_desc[] array in a more NUMA-friendly way. )
269 If you don't know what to do here, say N.
271 config NUMA_MIGRATE_IRQ_DESC
272 bool "Move irq desc when changing irq smp_affinity"
273 depends on SPARSE_IRQ && NUMA
276 This enables moving irq_desc to cpu/node that irq will use handled.
278 If you don't know what to do here, say N.
280 config X86_FIND_SMP_CONFIG
282 depends on X86_MPPARSE || X86_VOYAGER
285 bool "Enable MPS table" if ACPI
287 depends on X86_LOCAL_APIC
289 For old smp systems that do not have proper acpi support. Newer systems
290 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
293 prompt "Subarchitecture Type"
299 Choose this option if your computer is a standard PC or compatible.
305 Select this for an AMD Elan processor.
307 Do not use this option for K6/Athlon/Opteron processors!
309 If unsure, choose "PC-compatible" instead.
313 depends on X86_32 && (SMP || BROKEN) && !PCI
315 Voyager is an MCA-based 32-way capable SMP architecture proprietary
316 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
320 If you do not specifically know you have a Voyager based machine,
321 say N here, otherwise the kernel you build will not be bootable.
323 config X86_GENERICARCH
324 bool "Generic architecture"
327 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
328 subarchitectures. It is intended for a generic binary kernel.
329 if you select them all, kernel will probe it one by one. and will
335 bool "NUMAQ (IBM/Sequent)"
336 depends on SMP && X86_32 && PCI && X86_MPPARSE
339 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
340 NUMA multiquad box. This changes the way that processors are
341 bootstrapped, and uses Clustered Logical APIC addressing mode instead
342 of Flat Logical. You will need a new lynxer.elf file to flash your
343 firmware with - send email to <Martin.Bligh@us.ibm.com>.
346 bool "Summit/EXA (IBM x440)"
347 depends on X86_32 && SMP
349 This option is needed for IBM systems that use the Summit/EXA chipset.
350 In particular, it is needed for the x440.
353 bool "Support for Unisys ES7000 IA32 series"
354 depends on X86_32 && SMP
356 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
357 supposed to run on an IA32-based Unisys ES7000 system.
360 bool "Support for big SMP systems with more than 8 CPUs"
361 depends on X86_32 && SMP
363 This option is needed for the systems that have more than 8 CPUs
364 and if the system is not of any sub-arch type above.
369 bool "Support for ScaleMP vSMP"
371 depends on X86_64 && PCI
373 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
374 supposed to run on these EM64T-based machines. Only choose this option
375 if you have one of these machines.
380 bool "SGI 320/540 (Visual Workstation)"
381 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
383 The SGI Visual Workstation series is an IA32-based workstation
384 based on SGI systems chips with some legacy PC hardware attached.
386 Say Y here to create a kernel to run on the SGI 320 or 540.
388 A kernel compiled for the Visual Workstation will run on general
389 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
392 bool "RDC R-321x SoC"
395 select X86_REBOOTFIXUPS
397 This option is needed for RDC R-321x system-on-chip, also known
399 If you don't have one of these chips, you should say N here.
402 bool "SGI Ultraviolet"
405 This option is needed in order to support SGI Ultraviolet systems.
406 If you don't have one of these, you should say N here.
408 config SCHED_OMIT_FRAME_POINTER
410 prompt "Single-depth WCHAN output"
413 Calculate simpler /proc/<PID>/wchan values. If this option
414 is disabled then wchan values will recurse back to the
415 caller function. This provides more accurate wchan values,
416 at the expense of slightly more scheduling overhead.
418 If in doubt, say "Y".
420 menuconfig PARAVIRT_GUEST
421 bool "Paravirtualized guest support"
423 Say Y here to get to see options related to running Linux under
424 various hypervisors. This option alone does not add any kernel code.
426 If you say N, all options in this submenu will be skipped and disabled.
430 source "arch/x86/xen/Kconfig"
433 bool "VMI Guest support"
436 depends on !X86_VOYAGER
438 VMI provides a paravirtualized interface to the VMware ESX server
439 (it could be used by other hypervisors in theory too, but is not
440 at the moment), by linking the kernel to a GPL-ed ROM module
441 provided by the hypervisor.
444 bool "KVM paravirtualized clock"
446 select PARAVIRT_CLOCK
447 depends on !X86_VOYAGER
449 Turning on this option will allow you to run a paravirtualized clock
450 when running over the KVM hypervisor. Instead of relying on a PIT
451 (or probably other) emulation by the underlying device model, the host
452 provides the guest with timing infrastructure such as time of day, and
456 bool "KVM Guest support"
458 depends on !X86_VOYAGER
460 This option enables various optimizations for running under the KVM
463 source "arch/x86/lguest/Kconfig"
466 bool "Enable paravirtualization code"
467 depends on !X86_VOYAGER
469 This changes the kernel so it can modify itself when it is run
470 under a hypervisor, potentially improving performance significantly
471 over full virtualization. However, when run without a hypervisor
472 the kernel is theoretically slower and slightly larger.
474 config PARAVIRT_CLOCK
480 config PARAVIRT_DEBUG
481 bool "paravirt-ops debugging"
482 depends on PARAVIRT && DEBUG_KERNEL
484 Enable to debug paravirt_ops internals. Specifically, BUG if
485 a paravirt_op is missing when it is called.
490 This option adds a kernel parameter 'memtest', which allows memtest
492 memtest=0, mean disabled; -- default
493 memtest=1, mean do 1 test pattern;
495 memtest=4, mean do 4 test patterns.
496 If you are unsure how to answer this question, answer N.
498 config X86_SUMMIT_NUMA
500 depends on X86_32 && NUMA && X86_GENERICARCH
502 config X86_CYCLONE_TIMER
504 depends on X86_GENERICARCH
506 source "arch/x86/Kconfig.cpu"
510 prompt "HPET Timer Support" if X86_32
512 Use the IA-PC HPET (High Precision Event Timer) to manage
513 time in preference to the PIT and RTC, if a HPET is
515 HPET is the next generation timer replacing legacy 8254s.
516 The HPET provides a stable time base on SMP
517 systems, unlike the TSC, but it is more expensive to access,
518 as it is off-chip. You can find the HPET spec at
519 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
521 You can safely choose Y here. However, HPET will only be
522 activated if the platform and the BIOS support this feature.
523 Otherwise the 8254 will be used for timing services.
525 Choose N to continue using the legacy 8254 timer.
527 config HPET_EMULATE_RTC
529 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
531 # Mark as embedded because too many people got it wrong.
532 # The code disables itself when not needed.
535 bool "Enable DMI scanning" if EMBEDDED
537 Enabled scanning of DMI to identify machine quirks. Say Y
538 here unless you have verified that your setup is not
539 affected by entries in the DMI blacklist. Required by PNP
543 bool "GART IOMMU support" if EMBEDDED
547 depends on X86_64 && PCI
549 Support for full DMA access of devices with 32bit memory access only
550 on systems with more than 3GB. This is usually needed for USB,
551 sound, many IDE/SATA chipsets and some other devices.
552 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
553 based hardware IOMMU and a software bounce buffer based IOMMU used
554 on Intel systems and as fallback.
555 The code is only active when needed (enough memory and limited
556 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
560 bool "IBM Calgary IOMMU support"
562 depends on X86_64 && PCI && EXPERIMENTAL
564 Support for hardware IOMMUs in IBM's xSeries x366 and x460
565 systems. Needed to run systems with more than 3GB of memory
566 properly with 32-bit PCI devices that do not support DAC
567 (Double Address Cycle). Calgary also supports bus level
568 isolation, where all DMAs pass through the IOMMU. This
569 prevents them from going anywhere except their intended
570 destination. This catches hard-to-find kernel bugs and
571 mis-behaving drivers and devices that do not use the DMA-API
572 properly to set up their DMA buffers. The IOMMU can be
573 turned off at boot time with the iommu=off parameter.
574 Normally the kernel will make the right choice by itself.
577 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
579 prompt "Should Calgary be enabled by default?"
580 depends on CALGARY_IOMMU
582 Should Calgary be enabled by default? if you choose 'y', Calgary
583 will be used (if it exists). If you choose 'n', Calgary will not be
584 used even if it exists. If you choose 'n' and would like to use
585 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
589 bool "AMD IOMMU support"
592 depends on X86_64 && PCI && ACPI
594 With this option you can enable support for AMD IOMMU hardware in
595 your system. An IOMMU is a hardware component which provides
596 remapping of DMA memory accesses from devices. With an AMD IOMMU you
597 can isolate the the DMA memory of different devices and protect the
598 system from misbehaving device drivers or hardware.
600 You can find out if your system has an AMD IOMMU if you look into
601 your BIOS for an option to enable it or if you have an IVRS ACPI
604 config AMD_IOMMU_STATS
605 bool "Export AMD IOMMU statistics to debugfs"
609 This option enables code in the AMD IOMMU driver to collect various
610 statistics about whats happening in the driver and exports that
611 information to userspace via debugfs.
614 # need this always selected by IOMMU for the VIA workaround
618 Support for software bounce buffers used on x86-64 systems
619 which don't have a hardware IOMMU (e.g. the current generation
620 of Intel's x86-64 CPUs). Using this PCI devices which can only
621 access 32-bits of memory can be used on systems with more than
622 3 GB of memory. If unsure, say Y.
625 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
628 def_bool (AMD_IOMMU || DMAR)
631 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
632 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
633 select CPUMASK_OFFSTACK
636 Configure maximum number of CPUS and NUMA Nodes for this architecture.
640 int "Maximum number of CPUs" if SMP && !MAXSMP
641 range 2 512 if SMP && !MAXSMP
643 default "4096" if MAXSMP
644 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
647 This allows you to specify the maximum number of CPUs which this
648 kernel will support. The maximum supported value is 512 and the
649 minimum value which makes sense is 2.
651 This is purely to save memory - each supported CPU adds
652 approximately eight kilobytes to the kernel image.
655 bool "SMT (Hyperthreading) scheduler support"
658 SMT scheduler support improves the CPU scheduler's decision making
659 when dealing with Intel Pentium 4 chips with HyperThreading at a
660 cost of slightly increased overhead in some places. If unsure say
665 prompt "Multi-core scheduler support"
668 Multi-core scheduler support improves the CPU scheduler's decision
669 making when dealing with multi-core CPU chips at a cost of slightly
670 increased overhead in some places. If unsure say N here.
672 source "kernel/Kconfig.preempt"
675 bool "Local APIC support on uniprocessors"
676 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
678 A local APIC (Advanced Programmable Interrupt Controller) is an
679 integrated interrupt controller in the CPU. If you have a single-CPU
680 system which has a processor with a local APIC, you can say Y here to
681 enable and use it. If you say Y here even though your machine doesn't
682 have a local APIC, then the kernel will still run with no slowdown at
683 all. The local APIC supports CPU-generated self-interrupts (timer,
684 performance counters), and the NMI watchdog which detects hard
688 bool "IO-APIC support on uniprocessors"
689 depends on X86_UP_APIC
691 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
692 SMP-capable replacement for PC-style interrupt controllers. Most
693 SMP systems and many recent uniprocessor systems have one.
695 If you have a single-CPU system with an IO-APIC, you can say Y here
696 to use it. If you say Y here even though your machine doesn't have
697 an IO-APIC, then the kernel will still run with no slowdown at all.
699 config X86_LOCAL_APIC
701 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
705 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
707 config X86_VISWS_APIC
709 depends on X86_32 && X86_VISWS
711 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
712 bool "Reroute for broken boot IRQs"
714 depends on X86_IO_APIC
716 This option enables a workaround that fixes a source of
717 spurious interrupts. This is recommended when threaded
718 interrupt handling is used on systems where the generation of
719 superfluous "boot interrupts" cannot be disabled.
721 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
722 entry in the chipset's IO-APIC is masked (as, e.g. the RT
723 kernel does during interrupt handling). On chipsets where this
724 boot IRQ generation cannot be disabled, this workaround keeps
725 the original IRQ line masked so that only the equivalent "boot
726 IRQ" is delivered to the CPUs. The workaround also tells the
727 kernel to set up the IRQ handler on the boot IRQ line. In this
728 way only one interrupt is delivered to the kernel. Otherwise
729 the spurious second interrupt may cause the kernel to bring
730 down (vital) interrupt lines.
732 Only affects "broken" chipsets. Interrupt sharing may be
733 increased on these systems.
736 bool "Machine Check Exception"
737 depends on !X86_VOYAGER
739 Machine Check Exception support allows the processor to notify the
740 kernel if it detects a problem (e.g. overheating, component failure).
741 The action the kernel takes depends on the severity of the problem,
742 ranging from a warning message on the console, to halting the machine.
743 Your processor must be a Pentium or newer to support this - check the
744 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
745 have a design flaw which leads to false MCE events - hence MCE is
746 disabled on all P5 processors, unless explicitly enabled with "mce"
747 as a boot argument. Similarly, if MCE is built in and creates a
748 problem on some new non-standard machine, you can boot with "nomce"
749 to disable it. MCE support simply ignores non-MCE processors like
750 the 386 and 486, so nearly everyone can say Y here.
754 prompt "Intel MCE features"
755 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
757 Additional support for intel specific MCE features such as
762 prompt "AMD MCE features"
763 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
765 Additional support for AMD specific MCE features such as
766 the DRAM Error Threshold.
768 config X86_MCE_NONFATAL
769 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
770 depends on X86_32 && X86_MCE
772 Enabling this feature starts a timer that triggers every 5 seconds which
773 will look at the machine check registers to see if anything happened.
774 Non-fatal problems automatically get corrected (but still logged).
775 Disable this if you don't want to see these messages.
776 Seeing the messages this option prints out may be indicative of dying
777 or out-of-spec (ie, overclocked) hardware.
778 This option only does something on certain CPUs.
779 (AMD Athlon/Duron and Intel Pentium 4)
781 config X86_MCE_P4THERMAL
782 bool "check for P4 thermal throttling interrupt."
783 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
785 Enabling this feature will cause a message to be printed when the P4
786 enters thermal throttling.
789 bool "Enable VM86 support" if EMBEDDED
793 This option is required by programs like DOSEMU to run 16-bit legacy
794 code on X86 processors. It also may be needed by software like
795 XFree86 to initialize some video cards via BIOS. Disabling this
796 option saves about 6k.
799 tristate "Toshiba Laptop support"
802 This adds a driver to safely access the System Management Mode of
803 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
804 not work on models with a Phoenix BIOS. The System Management Mode
805 is used to set the BIOS and power saving options on Toshiba portables.
807 For information on utilities to make use of this driver see the
808 Toshiba Linux utilities web site at:
809 <http://www.buzzard.org.uk/toshiba/>.
811 Say Y if you intend to run this kernel on a Toshiba portable.
815 tristate "Dell laptop support"
817 This adds a driver to safely access the System Management Mode
818 of the CPU on the Dell Inspiron 8000. The System Management Mode
819 is used to read cpu temperature and cooling fan status and to
820 control the fans on the I8K portables.
822 This driver has been tested only on the Inspiron 8000 but it may
823 also work with other Dell laptops. You can force loading on other
824 models by passing the parameter `force=1' to the module. Use at
827 For information on utilities to make use of this driver see the
828 I8K Linux utilities web site at:
829 <http://people.debian.org/~dz/i8k/>
831 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
834 config X86_REBOOTFIXUPS
835 bool "Enable X86 board specific fixups for reboot"
838 This enables chipset and/or board specific fixups to be done
839 in order to get reboot to work correctly. This is only needed on
840 some combinations of hardware and BIOS. The symptom, for which
841 this config is intended, is when reboot ends with a stalled/hung
844 Currently, the only fixup is for the Geode machines using
845 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
847 Say Y if you want to enable the fixup. Currently, it's safe to
848 enable this option even if you don't need it.
852 tristate "/dev/cpu/microcode - microcode support"
855 If you say Y here, you will be able to update the microcode on
856 certain Intel and AMD processors. The Intel support is for the
857 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
858 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
859 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
860 You will obviously need the actual microcode binary data itself
861 which is not shipped with the Linux kernel.
863 This option selects the general module only, you need to select
864 at least one vendor specific module as well.
866 To compile this driver as a module, choose M here: the
867 module will be called microcode.
869 config MICROCODE_INTEL
870 bool "Intel microcode patch loading support"
875 This options enables microcode patch loading support for Intel
878 For latest news and information on obtaining all the required
879 Intel ingredients for this driver, check:
880 <http://www.urbanmyth.org/microcode/>.
883 bool "AMD microcode patch loading support"
887 If you select this option, microcode patch loading support for AMD
888 processors will be enabled.
890 config MICROCODE_OLD_INTERFACE
895 tristate "/dev/cpu/*/msr - Model-specific register support"
897 This device gives privileged processes access to the x86
898 Model-Specific Registers (MSRs). It is a character device with
899 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
900 MSR accesses are directed to a specific CPU on multi-processor
904 tristate "/dev/cpu/*/cpuid - CPU information support"
906 This device gives processes access to the x86 CPUID instruction to
907 be executed on a specific processor. It is a character device
908 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
912 prompt "High Memory Support"
913 default HIGHMEM4G if !X86_NUMAQ
914 default HIGHMEM64G if X86_NUMAQ
919 depends on !X86_NUMAQ
921 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
922 However, the address space of 32-bit x86 processors is only 4
923 Gigabytes large. That means that, if you have a large amount of
924 physical memory, not all of it can be "permanently mapped" by the
925 kernel. The physical memory that's not permanently mapped is called
928 If you are compiling a kernel which will never run on a machine with
929 more than 1 Gigabyte total physical RAM, answer "off" here (default
930 choice and suitable for most users). This will result in a "3GB/1GB"
931 split: 3GB are mapped so that each process sees a 3GB virtual memory
932 space and the remaining part of the 4GB virtual memory space is used
933 by the kernel to permanently map as much physical memory as
936 If the machine has between 1 and 4 Gigabytes physical RAM, then
939 If more than 4 Gigabytes is used then answer "64GB" here. This
940 selection turns Intel PAE (Physical Address Extension) mode on.
941 PAE implements 3-level paging on IA32 processors. PAE is fully
942 supported by Linux, PAE mode is implemented on all recent Intel
943 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
944 then the kernel will not boot on CPUs that don't support PAE!
946 The actual amount of total physical memory will either be
947 auto detected or can be forced by using a kernel command line option
948 such as "mem=256M". (Try "man bootparam" or see the documentation of
949 your boot loader (lilo or loadlin) about how to pass options to the
950 kernel at boot time.)
952 If unsure, say "off".
956 depends on !X86_NUMAQ
958 Select this if you have a 32-bit processor and between 1 and 4
959 gigabytes of physical RAM.
963 depends on !M386 && !M486
966 Select this if you have a 32-bit processor and more than 4
967 gigabytes of physical RAM.
972 depends on EXPERIMENTAL
973 prompt "Memory split" if EMBEDDED
977 Select the desired split between kernel and user memory.
979 If the address range available to the kernel is less than the
980 physical memory installed, the remaining memory will be available
981 as "high memory". Accessing high memory is a little more costly
982 than low memory, as it needs to be mapped into the kernel first.
983 Note that increasing the kernel address space limits the range
984 available to user programs, making the address space there
985 tighter. Selecting anything other than the default 3G/1G split
986 will also likely make your kernel incompatible with binary-only
989 If you are not absolutely sure what you are doing, leave this
993 bool "3G/1G user/kernel split"
994 config VMSPLIT_3G_OPT
996 bool "3G/1G user/kernel split (for full 1G low memory)"
998 bool "2G/2G user/kernel split"
999 config VMSPLIT_2G_OPT
1001 bool "2G/2G user/kernel split (for full 2G low memory)"
1003 bool "1G/3G user/kernel split"
1008 default 0xB0000000 if VMSPLIT_3G_OPT
1009 default 0x80000000 if VMSPLIT_2G
1010 default 0x78000000 if VMSPLIT_2G_OPT
1011 default 0x40000000 if VMSPLIT_1G
1017 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1020 bool "PAE (Physical Address Extension) Support"
1021 depends on X86_32 && !HIGHMEM4G
1023 PAE is required for NX support, and furthermore enables
1024 larger swapspace support for non-overcommit purposes. It
1025 has the cost of more pagetable lookup overhead, and also
1026 consumes more pagetable space per process.
1028 config ARCH_PHYS_ADDR_T_64BIT
1029 def_bool X86_64 || X86_PAE
1031 config DIRECT_GBPAGES
1032 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1036 Allow the kernel linear mapping to use 1GB pages on CPUs that
1037 support it. This can improve the kernel's performance a tiny bit by
1038 reducing TLB pressure. If in doubt, say "Y".
1040 # Common NUMA Features
1042 bool "Numa Memory Allocation and Scheduler Support"
1044 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1046 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1048 Enable NUMA (Non Uniform Memory Access) support.
1050 The kernel will try to allocate memory used by a CPU on the
1051 local memory controller of the CPU and add some more
1052 NUMA awareness to the kernel.
1054 For 64-bit this is recommended if the system is Intel Core i7
1055 (or later), AMD Opteron, or EM64T NUMA.
1057 For 32-bit this is only needed on (rare) 32-bit-only platforms
1058 that support NUMA topologies, such as NUMAQ / Summit, or if you
1059 boot a 32-bit kernel on a 64-bit NUMA platform.
1061 Otherwise, you should say N.
1063 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1064 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1068 prompt "Old style AMD Opteron NUMA detection"
1069 depends on X86_64 && NUMA && PCI
1071 Enable K8 NUMA node topology detection. You should say Y here if
1072 you have a multi processor AMD K8 system. This uses an old
1073 method to read the NUMA configuration directly from the builtin
1074 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1075 instead, which also takes priority if both are compiled in.
1077 config X86_64_ACPI_NUMA
1079 prompt "ACPI NUMA detection"
1080 depends on X86_64 && NUMA && ACPI && PCI
1083 Enable ACPI SRAT based node topology detection.
1085 # Some NUMA nodes have memory ranges that span
1086 # other nodes. Even though a pfn is valid and
1087 # between a node's start and end pfns, it may not
1088 # reside on that node. See memmap_init_zone()
1090 config NODES_SPAN_OTHER_NODES
1092 depends on X86_64_ACPI_NUMA
1095 bool "NUMA emulation"
1096 depends on X86_64 && NUMA
1098 Enable NUMA emulation. A flat machine will be split
1099 into virtual nodes when booted with "numa=fake=N", where N is the
1100 number of nodes. This is only useful for debugging.
1103 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1105 default "9" if MAXSMP
1106 default "6" if X86_64
1107 default "4" if X86_NUMAQ
1109 depends on NEED_MULTIPLE_NODES
1111 Specify the maximum number of NUMA Nodes available on the target
1112 system. Increases memory reserved to accomodate various tables.
1114 config HAVE_ARCH_BOOTMEM
1116 depends on X86_32 && NUMA
1118 config ARCH_HAVE_MEMORY_PRESENT
1120 depends on X86_32 && DISCONTIGMEM
1122 config NEED_NODE_MEMMAP_SIZE
1124 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1126 config HAVE_ARCH_ALLOC_REMAP
1128 depends on X86_32 && NUMA
1130 config ARCH_FLATMEM_ENABLE
1132 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1134 config ARCH_DISCONTIGMEM_ENABLE
1136 depends on NUMA && X86_32
1138 config ARCH_DISCONTIGMEM_DEFAULT
1140 depends on NUMA && X86_32
1142 config ARCH_SPARSEMEM_DEFAULT
1146 config ARCH_SPARSEMEM_ENABLE
1148 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH
1149 select SPARSEMEM_STATIC if X86_32
1150 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1152 config ARCH_SELECT_MEMORY_MODEL
1154 depends on ARCH_SPARSEMEM_ENABLE
1156 config ARCH_MEMORY_PROBE
1158 depends on MEMORY_HOTPLUG
1163 bool "Allocate 3rd-level pagetables from highmem"
1164 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1166 The VM uses one page table entry for each page of physical memory.
1167 For systems with a lot of RAM, this can be wasteful of precious
1168 low memory. Setting this option will put user-space page table
1169 entries in high memory.
1171 config X86_CHECK_BIOS_CORRUPTION
1172 bool "Check for low memory corruption"
1174 Periodically check for memory corruption in low memory, which
1175 is suspected to be caused by BIOS. Even when enabled in the
1176 configuration, it is disabled at runtime. Enable it by
1177 setting "memory_corruption_check=1" on the kernel command
1178 line. By default it scans the low 64k of memory every 60
1179 seconds; see the memory_corruption_check_size and
1180 memory_corruption_check_period parameters in
1181 Documentation/kernel-parameters.txt to adjust this.
1183 When enabled with the default parameters, this option has
1184 almost no overhead, as it reserves a relatively small amount
1185 of memory and scans it infrequently. It both detects corruption
1186 and prevents it from affecting the running system.
1188 It is, however, intended as a diagnostic tool; if repeatable
1189 BIOS-originated corruption always affects the same memory,
1190 you can use memmap= to prevent the kernel from using that
1193 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1194 bool "Set the default setting of memory_corruption_check"
1195 depends on X86_CHECK_BIOS_CORRUPTION
1198 Set whether the default state of memory_corruption_check is
1201 config X86_RESERVE_LOW_64K
1202 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1205 Reserve the first 64K of physical RAM on BIOSes that are known
1206 to potentially corrupt that memory range. A numbers of BIOSes are
1207 known to utilize this area during suspend/resume, so it must not
1208 be used by the kernel.
1210 Set this to N if you are absolutely sure that you trust the BIOS
1211 to get all its memory reservations and usages right.
1213 If you have doubts about the BIOS (e.g. suspend/resume does not
1214 work or there's kernel crashes after certain hardware hotplug
1215 events) and it's not AMI or Phoenix, then you might want to enable
1216 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1217 corruption patterns.
1221 config MATH_EMULATION
1223 prompt "Math emulation" if X86_32
1225 Linux can emulate a math coprocessor (used for floating point
1226 operations) if you don't have one. 486DX and Pentium processors have
1227 a math coprocessor built in, 486SX and 386 do not, unless you added
1228 a 487DX or 387, respectively. (The messages during boot time can
1229 give you some hints here ["man dmesg"].) Everyone needs either a
1230 coprocessor or this emulation.
1232 If you don't have a math coprocessor, you need to say Y here; if you
1233 say Y here even though you have a coprocessor, the coprocessor will
1234 be used nevertheless. (This behavior can be changed with the kernel
1235 command line option "no387", which comes handy if your coprocessor
1236 is broken. Try "man bootparam" or see the documentation of your boot
1237 loader (lilo or loadlin) about how to pass options to the kernel at
1238 boot time.) This means that it is a good idea to say Y here if you
1239 intend to use this kernel on different machines.
1241 More information about the internals of the Linux math coprocessor
1242 emulation can be found in <file:arch/x86/math-emu/README>.
1244 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1245 kernel, it won't hurt.
1248 bool "MTRR (Memory Type Range Register) support"
1250 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1251 the Memory Type Range Registers (MTRRs) may be used to control
1252 processor access to memory ranges. This is most useful if you have
1253 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1254 allows bus write transfers to be combined into a larger transfer
1255 before bursting over the PCI/AGP bus. This can increase performance
1256 of image write operations 2.5 times or more. Saying Y here creates a
1257 /proc/mtrr file which may be used to manipulate your processor's
1258 MTRRs. Typically the X server should use this.
1260 This code has a reasonably generic interface so that similar
1261 control registers on other processors can be easily supported
1264 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1265 Registers (ARRs) which provide a similar functionality to MTRRs. For
1266 these, the ARRs are used to emulate the MTRRs.
1267 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1268 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1269 write-combining. All of these processors are supported by this code
1270 and it makes sense to say Y here if you have one of them.
1272 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1273 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1274 can lead to all sorts of problems, so it's good to say Y here.
1276 You can safely say Y even if your machine doesn't have MTRRs, you'll
1277 just add about 9 KB to your kernel.
1279 See <file:Documentation/x86/mtrr.txt> for more information.
1281 config MTRR_SANITIZER
1283 prompt "MTRR cleanup support"
1286 Convert MTRR layout from continuous to discrete, so X drivers can
1287 add writeback entries.
1289 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1290 The largest mtrr entry size for a continous block can be set with
1295 config MTRR_SANITIZER_ENABLE_DEFAULT
1296 int "MTRR cleanup enable value (0-1)"
1299 depends on MTRR_SANITIZER
1301 Enable mtrr cleanup default value
1303 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1304 int "MTRR cleanup spare reg num (0-7)"
1307 depends on MTRR_SANITIZER
1309 mtrr cleanup spare entries default, it can be changed via
1310 mtrr_spare_reg_nr=N on the kernel command line.
1314 prompt "x86 PAT support"
1317 Use PAT attributes to setup page level cache control.
1319 PATs are the modern equivalents of MTRRs and are much more
1320 flexible than MTRRs.
1322 Say N here if you see bootup problems (boot crash, boot hang,
1323 spontaneous reboots) or a non-working video driver.
1328 bool "EFI runtime service support"
1331 This enables the kernel to use EFI runtime services that are
1332 available (such as the EFI variable services).
1334 This option is only useful on systems that have EFI firmware.
1335 In addition, you should use the latest ELILO loader available
1336 at <http://elilo.sourceforge.net> in order to take advantage
1337 of EFI runtime services. However, even with this option, the
1338 resultant kernel should continue to boot on existing non-EFI
1343 prompt "Enable seccomp to safely compute untrusted bytecode"
1345 This kernel feature is useful for number crunching applications
1346 that may need to compute untrusted bytecode during their
1347 execution. By using pipes or other transports made available to
1348 the process as file descriptors supporting the read/write
1349 syscalls, it's possible to isolate those applications in
1350 their own address space using seccomp. Once seccomp is
1351 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1352 and the task is only allowed to execute a few safe syscalls
1353 defined by each seccomp mode.
1355 If unsure, say Y. Only embedded should say N here.
1357 config CC_STACKPROTECTOR_ALL
1360 config CC_STACKPROTECTOR
1361 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1362 select CC_STACKPROTECTOR_ALL
1364 This option turns on the -fstack-protector GCC feature. This
1365 feature puts, at the beginning of functions, a canary value on
1366 the stack just before the return address, and validates
1367 the value just before actually returning. Stack based buffer
1368 overflows (that need to overwrite this return address) now also
1369 overwrite the canary, which gets detected and the attack is then
1370 neutralized via a kernel panic.
1372 This feature requires gcc version 4.2 or above, or a distribution
1373 gcc with the feature backported. Older versions are automatically
1374 detected and for those versions, this configuration option is
1375 ignored. (and a warning is printed during bootup)
1377 source kernel/Kconfig.hz
1380 bool "kexec system call"
1381 depends on X86_BIOS_REBOOT
1383 kexec is a system call that implements the ability to shutdown your
1384 current kernel, and to start another kernel. It is like a reboot
1385 but it is independent of the system firmware. And like a reboot
1386 you can start any kernel with it, not just Linux.
1388 The name comes from the similarity to the exec system call.
1390 It is an ongoing process to be certain the hardware in a machine
1391 is properly shutdown, so do not be surprised if this code does not
1392 initially work for you. It may help to enable device hotplugging
1393 support. As of this writing the exact hardware interface is
1394 strongly in flux, so no good recommendation can be made.
1397 bool "kernel crash dumps"
1398 depends on X86_64 || (X86_32 && HIGHMEM)
1400 Generate crash dump after being started by kexec.
1401 This should be normally only set in special crash dump kernels
1402 which are loaded in the main kernel with kexec-tools into
1403 a specially reserved region and then later executed after
1404 a crash by kdump/kexec. The crash dump kernel must be compiled
1405 to a memory address not used by the main kernel or BIOS using
1406 PHYSICAL_START, or it must be built as a relocatable image
1407 (CONFIG_RELOCATABLE=y).
1408 For more details see Documentation/kdump/kdump.txt
1411 bool "kexec jump (EXPERIMENTAL)"
1412 depends on EXPERIMENTAL
1413 depends on KEXEC && HIBERNATION && X86_32
1415 Jump between original kernel and kexeced kernel and invoke
1416 code in physical address mode via KEXEC
1418 config PHYSICAL_START
1419 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1420 default "0x1000000" if X86_NUMAQ
1421 default "0x200000" if X86_64
1424 This gives the physical address where the kernel is loaded.
1426 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1427 bzImage will decompress itself to above physical address and
1428 run from there. Otherwise, bzImage will run from the address where
1429 it has been loaded by the boot loader and will ignore above physical
1432 In normal kdump cases one does not have to set/change this option
1433 as now bzImage can be compiled as a completely relocatable image
1434 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1435 address. This option is mainly useful for the folks who don't want
1436 to use a bzImage for capturing the crash dump and want to use a
1437 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1438 to be specifically compiled to run from a specific memory area
1439 (normally a reserved region) and this option comes handy.
1441 So if you are using bzImage for capturing the crash dump, leave
1442 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1443 Otherwise if you plan to use vmlinux for capturing the crash dump
1444 change this value to start of the reserved region (Typically 16MB
1445 0x1000000). In other words, it can be set based on the "X" value as
1446 specified in the "crashkernel=YM@XM" command line boot parameter
1447 passed to the panic-ed kernel. Typically this parameter is set as
1448 crashkernel=64M@16M. Please take a look at
1449 Documentation/kdump/kdump.txt for more details about crash dumps.
1451 Usage of bzImage for capturing the crash dump is recommended as
1452 one does not have to build two kernels. Same kernel can be used
1453 as production kernel and capture kernel. Above option should have
1454 gone away after relocatable bzImage support is introduced. But it
1455 is present because there are users out there who continue to use
1456 vmlinux for dump capture. This option should go away down the
1459 Don't change this unless you know what you are doing.
1462 bool "Build a relocatable kernel (EXPERIMENTAL)"
1463 depends on EXPERIMENTAL
1465 This builds a kernel image that retains relocation information
1466 so it can be loaded someplace besides the default 1MB.
1467 The relocations tend to make the kernel binary about 10% larger,
1468 but are discarded at runtime.
1470 One use is for the kexec on panic case where the recovery kernel
1471 must live at a different physical address than the primary
1474 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1475 it has been loaded at and the compile time physical address
1476 (CONFIG_PHYSICAL_START) is ignored.
1478 config PHYSICAL_ALIGN
1480 prompt "Alignment value to which kernel should be aligned" if X86_32
1481 default "0x100000" if X86_32
1482 default "0x200000" if X86_64
1483 range 0x2000 0x400000
1485 This value puts the alignment restrictions on physical address
1486 where kernel is loaded and run from. Kernel is compiled for an
1487 address which meets above alignment restriction.
1489 If bootloader loads the kernel at a non-aligned address and
1490 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1491 address aligned to above value and run from there.
1493 If bootloader loads the kernel at a non-aligned address and
1494 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1495 load address and decompress itself to the address it has been
1496 compiled for and run from there. The address for which kernel is
1497 compiled already meets above alignment restrictions. Hence the
1498 end result is that kernel runs from a physical address meeting
1499 above alignment restrictions.
1501 Don't change this unless you know what you are doing.
1504 bool "Support for hot-pluggable CPUs"
1505 depends on SMP && HOTPLUG && !X86_VOYAGER
1507 Say Y here to allow turning CPUs off and on. CPUs can be
1508 controlled through /sys/devices/system/cpu.
1509 ( Note: power management support will enable this option
1510 automatically on SMP systems. )
1511 Say N if you want to disable CPU hotplug.
1515 prompt "Compat VDSO support"
1516 depends on X86_32 || IA32_EMULATION
1518 Map the 32-bit VDSO to the predictable old-style address too.
1520 Say N here if you are running a sufficiently recent glibc
1521 version (2.3.3 or later), to remove the high-mapped
1522 VDSO mapping and to exclusively use the randomized VDSO.
1527 bool "Built-in kernel command line"
1530 Allow for specifying boot arguments to the kernel at
1531 build time. On some systems (e.g. embedded ones), it is
1532 necessary or convenient to provide some or all of the
1533 kernel boot arguments with the kernel itself (that is,
1534 to not rely on the boot loader to provide them.)
1536 To compile command line arguments into the kernel,
1537 set this option to 'Y', then fill in the
1538 the boot arguments in CONFIG_CMDLINE.
1540 Systems with fully functional boot loaders (i.e. non-embedded)
1541 should leave this option set to 'N'.
1544 string "Built-in kernel command string"
1545 depends on CMDLINE_BOOL
1548 Enter arguments here that should be compiled into the kernel
1549 image and used at boot time. If the boot loader provides a
1550 command line at boot time, it is appended to this string to
1551 form the full kernel command line, when the system boots.
1553 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1554 change this behavior.
1556 In most cases, the command line (whether built-in or provided
1557 by the boot loader) should specify the device for the root
1560 config CMDLINE_OVERRIDE
1561 bool "Built-in command line overrides boot loader arguments"
1563 depends on CMDLINE_BOOL
1565 Set this option to 'Y' to have the kernel ignore the boot loader
1566 command line, and use ONLY the built-in command line.
1568 This is used to work around broken boot loaders. This should
1569 be set to 'N' under normal conditions.
1573 config ARCH_ENABLE_MEMORY_HOTPLUG
1575 depends on X86_64 || (X86_32 && HIGHMEM)
1577 config ARCH_ENABLE_MEMORY_HOTREMOVE
1579 depends on MEMORY_HOTPLUG
1581 config HAVE_ARCH_EARLY_PFN_TO_NID
1585 menu "Power management and ACPI options"
1586 depends on !X86_VOYAGER
1588 config ARCH_HIBERNATION_HEADER
1590 depends on X86_64 && HIBERNATION
1592 source "kernel/power/Kconfig"
1594 source "drivers/acpi/Kconfig"
1599 depends on APM || APM_MODULE
1602 tristate "APM (Advanced Power Management) BIOS support"
1603 depends on X86_32 && PM_SLEEP
1605 APM is a BIOS specification for saving power using several different
1606 techniques. This is mostly useful for battery powered laptops with
1607 APM compliant BIOSes. If you say Y here, the system time will be
1608 reset after a RESUME operation, the /proc/apm device will provide
1609 battery status information, and user-space programs will receive
1610 notification of APM "events" (e.g. battery status change).
1612 If you select "Y" here, you can disable actual use of the APM
1613 BIOS by passing the "apm=off" option to the kernel at boot time.
1615 Note that the APM support is almost completely disabled for
1616 machines with more than one CPU.
1618 In order to use APM, you will need supporting software. For location
1619 and more information, read <file:Documentation/power/pm.txt> and the
1620 Battery Powered Linux mini-HOWTO, available from
1621 <http://www.tldp.org/docs.html#howto>.
1623 This driver does not spin down disk drives (see the hdparm(8)
1624 manpage ("man 8 hdparm") for that), and it doesn't turn off
1625 VESA-compliant "green" monitors.
1627 This driver does not support the TI 4000M TravelMate and the ACER
1628 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1629 desktop machines also don't have compliant BIOSes, and this driver
1630 may cause those machines to panic during the boot phase.
1632 Generally, if you don't have a battery in your machine, there isn't
1633 much point in using this driver and you should say N. If you get
1634 random kernel OOPSes or reboots that don't seem to be related to
1635 anything, try disabling/enabling this option (or disabling/enabling
1638 Some other things you should try when experiencing seemingly random,
1641 1) make sure that you have enough swap space and that it is
1643 2) pass the "no-hlt" option to the kernel
1644 3) switch on floating point emulation in the kernel and pass
1645 the "no387" option to the kernel
1646 4) pass the "floppy=nodma" option to the kernel
1647 5) pass the "mem=4M" option to the kernel (thereby disabling
1648 all but the first 4 MB of RAM)
1649 6) make sure that the CPU is not over clocked.
1650 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1651 8) disable the cache from your BIOS settings
1652 9) install a fan for the video card or exchange video RAM
1653 10) install a better fan for the CPU
1654 11) exchange RAM chips
1655 12) exchange the motherboard.
1657 To compile this driver as a module, choose M here: the
1658 module will be called apm.
1662 config APM_IGNORE_USER_SUSPEND
1663 bool "Ignore USER SUSPEND"
1665 This option will ignore USER SUSPEND requests. On machines with a
1666 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1667 series notebooks, it is necessary to say Y because of a BIOS bug.
1669 config APM_DO_ENABLE
1670 bool "Enable PM at boot time"
1672 Enable APM features at boot time. From page 36 of the APM BIOS
1673 specification: "When disabled, the APM BIOS does not automatically
1674 power manage devices, enter the Standby State, enter the Suspend
1675 State, or take power saving steps in response to CPU Idle calls."
1676 This driver will make CPU Idle calls when Linux is idle (unless this
1677 feature is turned off -- see "Do CPU IDLE calls", below). This
1678 should always save battery power, but more complicated APM features
1679 will be dependent on your BIOS implementation. You may need to turn
1680 this option off if your computer hangs at boot time when using APM
1681 support, or if it beeps continuously instead of suspending. Turn
1682 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1683 T400CDT. This is off by default since most machines do fine without
1687 bool "Make CPU Idle calls when idle"
1689 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1690 On some machines, this can activate improved power savings, such as
1691 a slowed CPU clock rate, when the machine is idle. These idle calls
1692 are made after the idle loop has run for some length of time (e.g.,
1693 333 mS). On some machines, this will cause a hang at boot time or
1694 whenever the CPU becomes idle. (On machines with more than one CPU,
1695 this option does nothing.)
1697 config APM_DISPLAY_BLANK
1698 bool "Enable console blanking using APM"
1700 Enable console blanking using the APM. Some laptops can use this to
1701 turn off the LCD backlight when the screen blanker of the Linux
1702 virtual console blanks the screen. Note that this is only used by
1703 the virtual console screen blanker, and won't turn off the backlight
1704 when using the X Window system. This also doesn't have anything to
1705 do with your VESA-compliant power-saving monitor. Further, this
1706 option doesn't work for all laptops -- it might not turn off your
1707 backlight at all, or it might print a lot of errors to the console,
1708 especially if you are using gpm.
1710 config APM_ALLOW_INTS
1711 bool "Allow interrupts during APM BIOS calls"
1713 Normally we disable external interrupts while we are making calls to
1714 the APM BIOS as a measure to lessen the effects of a badly behaving
1715 BIOS implementation. The BIOS should reenable interrupts if it
1716 needs to. Unfortunately, some BIOSes do not -- especially those in
1717 many of the newer IBM Thinkpads. If you experience hangs when you
1718 suspend, try setting this to Y. Otherwise, say N.
1722 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1724 source "drivers/cpuidle/Kconfig"
1726 source "drivers/idle/Kconfig"
1731 menu "Bus options (PCI etc.)"
1736 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1738 Find out whether you have a PCI motherboard. PCI is the name of a
1739 bus system, i.e. the way the CPU talks to the other stuff inside
1740 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1741 VESA. If you have PCI, say Y, otherwise N.
1744 prompt "PCI access mode"
1745 depends on X86_32 && PCI
1748 On PCI systems, the BIOS can be used to detect the PCI devices and
1749 determine their configuration. However, some old PCI motherboards
1750 have BIOS bugs and may crash if this is done. Also, some embedded
1751 PCI-based systems don't have any BIOS at all. Linux can also try to
1752 detect the PCI hardware directly without using the BIOS.
1754 With this option, you can specify how Linux should detect the
1755 PCI devices. If you choose "BIOS", the BIOS will be used,
1756 if you choose "Direct", the BIOS won't be used, and if you
1757 choose "MMConfig", then PCI Express MMCONFIG will be used.
1758 If you choose "Any", the kernel will try MMCONFIG, then the
1759 direct access method and falls back to the BIOS if that doesn't
1760 work. If unsure, go with the default, which is "Any".
1765 config PCI_GOMMCONFIG
1782 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1784 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1787 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1791 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1795 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1802 bool "Support mmconfig PCI config space access"
1803 depends on X86_64 && PCI && ACPI
1806 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1807 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1809 DMA remapping (DMAR) devices support enables independent address
1810 translations for Direct Memory Access (DMA) from devices.
1811 These DMA remapping devices are reported via ACPI tables
1812 and include PCI device scope covered by these DMA
1815 config DMAR_DEFAULT_ON
1817 prompt "Enable DMA Remapping Devices by default"
1820 Selecting this option will enable a DMAR device at boot time if
1821 one is found. If this option is not selected, DMAR support can
1822 be enabled by passing intel_iommu=on to the kernel. It is
1823 recommended you say N here while the DMAR code remains
1828 prompt "Support for Graphics workaround"
1831 Current Graphics drivers tend to use physical address
1832 for DMA and avoid using DMA APIs. Setting this config
1833 option permits the IOMMU driver to set a unity map for
1834 all the OS-visible memory. Hence the driver can continue
1835 to use physical addresses for DMA.
1837 config DMAR_FLOPPY_WA
1841 Floppy disk drivers are know to bypass DMA API calls
1842 thereby failing to work when IOMMU is enabled. This
1843 workaround will setup a 1:1 mapping for the first
1844 16M to make floppy (an ISA device) work.
1847 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1848 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1850 Supports Interrupt remapping for IO-APIC and MSI devices.
1851 To use x2apic mode in the CPU's which support x2APIC enhancements or
1852 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1854 source "drivers/pci/pcie/Kconfig"
1856 source "drivers/pci/Kconfig"
1858 # x86_64 have no ISA slots, but do have ISA-style DMA.
1866 depends on !X86_VOYAGER
1868 Find out whether you have ISA slots on your motherboard. ISA is the
1869 name of a bus system, i.e. the way the CPU talks to the other stuff
1870 inside your box. Other bus systems are PCI, EISA, MicroChannel
1871 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1872 newer boards don't support it. If you have ISA, say Y, otherwise N.
1878 The Extended Industry Standard Architecture (EISA) bus was
1879 developed as an open alternative to the IBM MicroChannel bus.
1881 The EISA bus provided some of the features of the IBM MicroChannel
1882 bus while maintaining backward compatibility with cards made for
1883 the older ISA bus. The EISA bus saw limited use between 1988 and
1884 1995 when it was made obsolete by the PCI bus.
1886 Say Y here if you are building a kernel for an EISA-based machine.
1890 source "drivers/eisa/Kconfig"
1893 bool "MCA support" if !X86_VOYAGER
1894 default y if X86_VOYAGER
1896 MicroChannel Architecture is found in some IBM PS/2 machines and
1897 laptops. It is a bus system similar to PCI or ISA. See
1898 <file:Documentation/mca.txt> (and especially the web page given
1899 there) before attempting to build an MCA bus kernel.
1901 source "drivers/mca/Kconfig"
1904 tristate "NatSemi SCx200 support"
1905 depends on !X86_VOYAGER
1907 This provides basic support for National Semiconductor's
1908 (now AMD's) Geode processors. The driver probes for the
1909 PCI-IDs of several on-chip devices, so its a good dependency
1910 for other scx200_* drivers.
1912 If compiled as a module, the driver is named scx200.
1914 config SCx200HR_TIMER
1915 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1916 depends on SCx200 && GENERIC_TIME
1919 This driver provides a clocksource built upon the on-chip
1920 27MHz high-resolution timer. Its also a workaround for
1921 NSC Geode SC-1100's buggy TSC, which loses time when the
1922 processor goes idle (as is done by the scheduler). The
1923 other workaround is idle=poll boot option.
1925 config GEODE_MFGPT_TIMER
1927 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1928 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1930 This driver provides a clock event source based on the MFGPT
1931 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1932 MFGPTs have a better resolution and max interval than the
1933 generic PIT, and are suitable for use as high-res timers.
1936 bool "One Laptop Per Child support"
1939 Add support for detecting the unique features of the OLPC
1946 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1948 source "drivers/pcmcia/Kconfig"
1950 source "drivers/pci/hotplug/Kconfig"
1955 menu "Executable file formats / Emulations"
1957 source "fs/Kconfig.binfmt"
1959 config IA32_EMULATION
1960 bool "IA32 Emulation"
1962 select COMPAT_BINFMT_ELF
1964 Include code to run 32-bit programs under a 64-bit kernel. You should
1965 likely turn this on, unless you're 100% sure that you don't have any
1966 32-bit programs left.
1969 tristate "IA32 a.out support"
1970 depends on IA32_EMULATION
1972 Support old a.out binaries in the 32bit emulation.
1976 depends on IA32_EMULATION
1978 config COMPAT_FOR_U64_ALIGNMENT
1982 config SYSVIPC_COMPAT
1984 depends on COMPAT && SYSVIPC
1989 config HAVE_ATOMIC_IOMAP
1993 source "net/Kconfig"
1995 source "drivers/Kconfig"
1997 source "drivers/firmware/Kconfig"
2001 source "arch/x86/Kconfig.debug"
2003 source "security/Kconfig"
2005 source "crypto/Kconfig"
2007 source "arch/x86/kvm/Kconfig"
2009 source "lib/Kconfig"
git://ftp.safe.ca / safe / jmp / linux-2.6 / blob