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_CPUMASK_OF_CPU_MAP
141 config ARCH_HIBERNATION_POSSIBLE
143 depends on !SMP || !X86_VOYAGER
145 config ARCH_SUSPEND_POSSIBLE
147 depends on !X86_VOYAGER
153 config ARCH_POPULATES_NODE_MAP
160 config ARCH_SUPPORTS_OPTIMIZED_INLINING
163 # Use the generic interrupt handling code in kernel/irq/:
164 config GENERIC_HARDIRQS
168 config GENERIC_IRQ_PROBE
172 config GENERIC_PENDING_IRQ
174 depends on GENERIC_HARDIRQS && SMP
179 depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)
182 config USE_GENERIC_SMP_HELPERS
188 depends on X86_32 && SMP
192 depends on X86_64 && SMP
197 depends on (X86_32 && !X86_VOYAGER) || X86_64
200 config X86_BIOS_REBOOT
202 depends on !X86_VOYAGER
205 config X86_TRAMPOLINE
207 depends on X86_SMP || (X86_VOYAGER && SMP) || (64BIT && ACPI_SLEEP)
210 config X86_32_LAZY_GS
212 depends on X86_32 && !CC_STACKPROTECTOR
216 source "init/Kconfig"
217 source "kernel/Kconfig.freezer"
219 menu "Processor type and features"
221 source "kernel/time/Kconfig"
224 bool "Symmetric multi-processing support"
226 This enables support for systems with more than one CPU. If you have
227 a system with only one CPU, like most personal computers, say N. If
228 you have a system with more than one CPU, say Y.
230 If you say N here, the kernel will run on single and multiprocessor
231 machines, but will use only one CPU of a multiprocessor machine. If
232 you say Y here, the kernel will run on many, but not all,
233 singleprocessor machines. On a singleprocessor machine, the kernel
234 will run faster if you say N here.
236 Note that if you say Y here and choose architecture "586" or
237 "Pentium" under "Processor family", the kernel will not work on 486
238 architectures. Similarly, multiprocessor kernels for the "PPro"
239 architecture may not work on all Pentium based boards.
241 People using multiprocessor machines who say Y here should also say
242 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
243 Management" code will be disabled if you say Y here.
245 See also <file:Documentation/i386/IO-APIC.txt>,
246 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
247 <http://www.tldp.org/docs.html#howto>.
249 If you don't know what to do here, say N.
251 config X86_HAS_BOOT_CPU_ID
253 depends on X86_VOYAGER
256 bool "Support sparse irq numbering"
257 depends on PCI_MSI || HT_IRQ
259 This enables support for sparse irqs. This is useful for distro
260 kernels that want to define a high CONFIG_NR_CPUS value but still
261 want to have low kernel memory footprint on smaller machines.
263 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
264 out the irq_desc[] array in a more NUMA-friendly way. )
266 If you don't know what to do here, say N.
268 config NUMA_MIGRATE_IRQ_DESC
269 bool "Move irq desc when changing irq smp_affinity"
270 depends on SPARSE_IRQ && NUMA
273 This enables moving irq_desc to cpu/node that irq will use handled.
275 If you don't know what to do here, say N.
277 config X86_FIND_SMP_CONFIG
279 depends on X86_MPPARSE || X86_VOYAGER
282 bool "Enable MPS table" if ACPI
284 depends on X86_LOCAL_APIC
286 For old smp systems that do not have proper acpi support. Newer systems
287 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
290 prompt "Subarchitecture Type"
296 Choose this option if your computer is a standard PC or compatible.
302 Select this for an AMD Elan processor.
304 Do not use this option for K6/Athlon/Opteron processors!
306 If unsure, choose "PC-compatible" instead.
310 depends on X86_32 && (SMP || BROKEN) && !PCI
312 Voyager is an MCA-based 32-way capable SMP architecture proprietary
313 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
317 If you do not specifically know you have a Voyager based machine,
318 say N here, otherwise the kernel you build will not be bootable.
320 config X86_GENERICARCH
321 bool "Generic architecture"
324 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
325 subarchitectures. It is intended for a generic binary kernel.
326 if you select them all, kernel will probe it one by one. and will
332 bool "NUMAQ (IBM/Sequent)"
333 depends on SMP && X86_32 && PCI && X86_MPPARSE
336 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
337 NUMA multiquad box. This changes the way that processors are
338 bootstrapped, and uses Clustered Logical APIC addressing mode instead
339 of Flat Logical. You will need a new lynxer.elf file to flash your
340 firmware with - send email to <Martin.Bligh@us.ibm.com>.
343 bool "Summit/EXA (IBM x440)"
344 depends on X86_32 && SMP
346 This option is needed for IBM systems that use the Summit/EXA chipset.
347 In particular, it is needed for the x440.
350 bool "Support for Unisys ES7000 IA32 series"
351 depends on X86_32 && SMP
353 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
354 supposed to run on an IA32-based Unisys ES7000 system.
357 bool "Support for big SMP systems with more than 8 CPUs"
358 depends on X86_32 && SMP
360 This option is needed for the systems that have more than 8 CPUs
361 and if the system is not of any sub-arch type above.
366 bool "Support for ScaleMP vSMP"
368 depends on X86_64 && PCI
370 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
371 supposed to run on these EM64T-based machines. Only choose this option
372 if you have one of these machines.
377 bool "SGI 320/540 (Visual Workstation)"
378 depends on X86_32 && PCI && !X86_VOYAGER && X86_MPPARSE && PCI_GODIRECT
380 The SGI Visual Workstation series is an IA32-based workstation
381 based on SGI systems chips with some legacy PC hardware attached.
383 Say Y here to create a kernel to run on the SGI 320 or 540.
385 A kernel compiled for the Visual Workstation will run on general
386 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
389 bool "RDC R-321x SoC"
392 select X86_REBOOTFIXUPS
394 This option is needed for RDC R-321x system-on-chip, also known
396 If you don't have one of these chips, you should say N here.
399 bool "SGI Ultraviolet"
402 This option is needed in order to support SGI Ultraviolet systems.
403 If you don't have one of these, you should say N here.
405 config SCHED_OMIT_FRAME_POINTER
407 prompt "Single-depth WCHAN output"
410 Calculate simpler /proc/<PID>/wchan values. If this option
411 is disabled then wchan values will recurse back to the
412 caller function. This provides more accurate wchan values,
413 at the expense of slightly more scheduling overhead.
415 If in doubt, say "Y".
417 menuconfig PARAVIRT_GUEST
418 bool "Paravirtualized guest support"
420 Say Y here to get to see options related to running Linux under
421 various hypervisors. This option alone does not add any kernel code.
423 If you say N, all options in this submenu will be skipped and disabled.
427 source "arch/x86/xen/Kconfig"
430 bool "VMI Guest support"
433 depends on !X86_VOYAGER
435 VMI provides a paravirtualized interface to the VMware ESX server
436 (it could be used by other hypervisors in theory too, but is not
437 at the moment), by linking the kernel to a GPL-ed ROM module
438 provided by the hypervisor.
441 bool "KVM paravirtualized clock"
443 select PARAVIRT_CLOCK
444 depends on !X86_VOYAGER
446 Turning on this option will allow you to run a paravirtualized clock
447 when running over the KVM hypervisor. Instead of relying on a PIT
448 (or probably other) emulation by the underlying device model, the host
449 provides the guest with timing infrastructure such as time of day, and
453 bool "KVM Guest support"
455 depends on !X86_VOYAGER
457 This option enables various optimizations for running under the KVM
460 source "arch/x86/lguest/Kconfig"
463 bool "Enable paravirtualization code"
464 depends on !X86_VOYAGER
466 This changes the kernel so it can modify itself when it is run
467 under a hypervisor, potentially improving performance significantly
468 over full virtualization. However, when run without a hypervisor
469 the kernel is theoretically slower and slightly larger.
471 config PARAVIRT_CLOCK
477 config PARAVIRT_DEBUG
478 bool "paravirt-ops debugging"
479 depends on PARAVIRT && DEBUG_KERNEL
481 Enable to debug paravirt_ops internals. Specifically, BUG if
482 a paravirt_op is missing when it is called.
487 This option adds a kernel parameter 'memtest', which allows memtest
489 memtest=0, mean disabled; -- default
490 memtest=1, mean do 1 test pattern;
492 memtest=4, mean do 4 test patterns.
493 If you are unsure how to answer this question, answer N.
495 config X86_SUMMIT_NUMA
497 depends on X86_32 && NUMA && X86_GENERICARCH
499 config X86_CYCLONE_TIMER
501 depends on X86_GENERICARCH
503 source "arch/x86/Kconfig.cpu"
507 prompt "HPET Timer Support" if X86_32
509 Use the IA-PC HPET (High Precision Event Timer) to manage
510 time in preference to the PIT and RTC, if a HPET is
512 HPET is the next generation timer replacing legacy 8254s.
513 The HPET provides a stable time base on SMP
514 systems, unlike the TSC, but it is more expensive to access,
515 as it is off-chip. You can find the HPET spec at
516 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
518 You can safely choose Y here. However, HPET will only be
519 activated if the platform and the BIOS support this feature.
520 Otherwise the 8254 will be used for timing services.
522 Choose N to continue using the legacy 8254 timer.
524 config HPET_EMULATE_RTC
526 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
528 # Mark as embedded because too many people got it wrong.
529 # The code disables itself when not needed.
532 bool "Enable DMI scanning" if EMBEDDED
534 Enabled scanning of DMI to identify machine quirks. Say Y
535 here unless you have verified that your setup is not
536 affected by entries in the DMI blacklist. Required by PNP
540 bool "GART IOMMU support" if EMBEDDED
544 depends on X86_64 && PCI
546 Support for full DMA access of devices with 32bit memory access only
547 on systems with more than 3GB. This is usually needed for USB,
548 sound, many IDE/SATA chipsets and some other devices.
549 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
550 based hardware IOMMU and a software bounce buffer based IOMMU used
551 on Intel systems and as fallback.
552 The code is only active when needed (enough memory and limited
553 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
557 bool "IBM Calgary IOMMU support"
559 depends on X86_64 && PCI && EXPERIMENTAL
561 Support for hardware IOMMUs in IBM's xSeries x366 and x460
562 systems. Needed to run systems with more than 3GB of memory
563 properly with 32-bit PCI devices that do not support DAC
564 (Double Address Cycle). Calgary also supports bus level
565 isolation, where all DMAs pass through the IOMMU. This
566 prevents them from going anywhere except their intended
567 destination. This catches hard-to-find kernel bugs and
568 mis-behaving drivers and devices that do not use the DMA-API
569 properly to set up their DMA buffers. The IOMMU can be
570 turned off at boot time with the iommu=off parameter.
571 Normally the kernel will make the right choice by itself.
574 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
576 prompt "Should Calgary be enabled by default?"
577 depends on CALGARY_IOMMU
579 Should Calgary be enabled by default? if you choose 'y', Calgary
580 will be used (if it exists). If you choose 'n', Calgary will not be
581 used even if it exists. If you choose 'n' and would like to use
582 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
586 bool "AMD IOMMU support"
589 depends on X86_64 && PCI && ACPI
591 With this option you can enable support for AMD IOMMU hardware in
592 your system. An IOMMU is a hardware component which provides
593 remapping of DMA memory accesses from devices. With an AMD IOMMU you
594 can isolate the the DMA memory of different devices and protect the
595 system from misbehaving device drivers or hardware.
597 You can find out if your system has an AMD IOMMU if you look into
598 your BIOS for an option to enable it or if you have an IVRS ACPI
601 config AMD_IOMMU_STATS
602 bool "Export AMD IOMMU statistics to debugfs"
606 This option enables code in the AMD IOMMU driver to collect various
607 statistics about whats happening in the driver and exports that
608 information to userspace via debugfs.
611 # need this always selected by IOMMU for the VIA workaround
615 Support for software bounce buffers used on x86-64 systems
616 which don't have a hardware IOMMU (e.g. the current generation
617 of Intel's x86-64 CPUs). Using this PCI devices which can only
618 access 32-bits of memory can be used on systems with more than
619 3 GB of memory. If unsure, say Y.
622 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
625 def_bool (AMD_IOMMU || DMAR)
628 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
629 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
630 select CPUMASK_OFFSTACK
633 Configure maximum number of CPUS and NUMA Nodes for this architecture.
637 int "Maximum number of CPUs" if SMP && !MAXSMP
638 range 2 512 if SMP && !MAXSMP
640 default "4096" if MAXSMP
641 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
644 This allows you to specify the maximum number of CPUs which this
645 kernel will support. The maximum supported value is 512 and the
646 minimum value which makes sense is 2.
648 This is purely to save memory - each supported CPU adds
649 approximately eight kilobytes to the kernel image.
652 bool "SMT (Hyperthreading) scheduler support"
655 SMT scheduler support improves the CPU scheduler's decision making
656 when dealing with Intel Pentium 4 chips with HyperThreading at a
657 cost of slightly increased overhead in some places. If unsure say
662 prompt "Multi-core scheduler support"
665 Multi-core scheduler support improves the CPU scheduler's decision
666 making when dealing with multi-core CPU chips at a cost of slightly
667 increased overhead in some places. If unsure say N here.
669 source "kernel/Kconfig.preempt"
672 bool "Local APIC support on uniprocessors"
673 depends on X86_32 && !SMP && !(X86_VOYAGER || X86_GENERICARCH)
675 A local APIC (Advanced Programmable Interrupt Controller) is an
676 integrated interrupt controller in the CPU. If you have a single-CPU
677 system which has a processor with a local APIC, you can say Y here to
678 enable and use it. If you say Y here even though your machine doesn't
679 have a local APIC, then the kernel will still run with no slowdown at
680 all. The local APIC supports CPU-generated self-interrupts (timer,
681 performance counters), and the NMI watchdog which detects hard
685 bool "IO-APIC support on uniprocessors"
686 depends on X86_UP_APIC
688 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
689 SMP-capable replacement for PC-style interrupt controllers. Most
690 SMP systems and many recent uniprocessor systems have one.
692 If you have a single-CPU system with an IO-APIC, you can say Y here
693 to use it. If you say Y here even though your machine doesn't have
694 an IO-APIC, then the kernel will still run with no slowdown at all.
696 config X86_LOCAL_APIC
698 depends on X86_64 || (X86_32 && (X86_UP_APIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
702 depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !X86_VOYAGER) || X86_GENERICARCH))
704 config X86_VISWS_APIC
706 depends on X86_32 && X86_VISWS
708 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
709 bool "Reroute for broken boot IRQs"
711 depends on X86_IO_APIC
713 This option enables a workaround that fixes a source of
714 spurious interrupts. This is recommended when threaded
715 interrupt handling is used on systems where the generation of
716 superfluous "boot interrupts" cannot be disabled.
718 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
719 entry in the chipset's IO-APIC is masked (as, e.g. the RT
720 kernel does during interrupt handling). On chipsets where this
721 boot IRQ generation cannot be disabled, this workaround keeps
722 the original IRQ line masked so that only the equivalent "boot
723 IRQ" is delivered to the CPUs. The workaround also tells the
724 kernel to set up the IRQ handler on the boot IRQ line. In this
725 way only one interrupt is delivered to the kernel. Otherwise
726 the spurious second interrupt may cause the kernel to bring
727 down (vital) interrupt lines.
729 Only affects "broken" chipsets. Interrupt sharing may be
730 increased on these systems.
733 bool "Machine Check Exception"
734 depends on !X86_VOYAGER
736 Machine Check Exception support allows the processor to notify the
737 kernel if it detects a problem (e.g. overheating, component failure).
738 The action the kernel takes depends on the severity of the problem,
739 ranging from a warning message on the console, to halting the machine.
740 Your processor must be a Pentium or newer to support this - check the
741 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
742 have a design flaw which leads to false MCE events - hence MCE is
743 disabled on all P5 processors, unless explicitly enabled with "mce"
744 as a boot argument. Similarly, if MCE is built in and creates a
745 problem on some new non-standard machine, you can boot with "nomce"
746 to disable it. MCE support simply ignores non-MCE processors like
747 the 386 and 486, so nearly everyone can say Y here.
751 prompt "Intel MCE features"
752 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
754 Additional support for intel specific MCE features such as
759 prompt "AMD MCE features"
760 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
762 Additional support for AMD specific MCE features such as
763 the DRAM Error Threshold.
765 config X86_MCE_NONFATAL
766 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
767 depends on X86_32 && X86_MCE
769 Enabling this feature starts a timer that triggers every 5 seconds which
770 will look at the machine check registers to see if anything happened.
771 Non-fatal problems automatically get corrected (but still logged).
772 Disable this if you don't want to see these messages.
773 Seeing the messages this option prints out may be indicative of dying
774 or out-of-spec (ie, overclocked) hardware.
775 This option only does something on certain CPUs.
776 (AMD Athlon/Duron and Intel Pentium 4)
778 config X86_MCE_P4THERMAL
779 bool "check for P4 thermal throttling interrupt."
780 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
782 Enabling this feature will cause a message to be printed when the P4
783 enters thermal throttling.
786 bool "Enable VM86 support" if EMBEDDED
790 This option is required by programs like DOSEMU to run 16-bit legacy
791 code on X86 processors. It also may be needed by software like
792 XFree86 to initialize some video cards via BIOS. Disabling this
793 option saves about 6k.
796 tristate "Toshiba Laptop support"
799 This adds a driver to safely access the System Management Mode of
800 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
801 not work on models with a Phoenix BIOS. The System Management Mode
802 is used to set the BIOS and power saving options on Toshiba portables.
804 For information on utilities to make use of this driver see the
805 Toshiba Linux utilities web site at:
806 <http://www.buzzard.org.uk/toshiba/>.
808 Say Y if you intend to run this kernel on a Toshiba portable.
812 tristate "Dell laptop support"
814 This adds a driver to safely access the System Management Mode
815 of the CPU on the Dell Inspiron 8000. The System Management Mode
816 is used to read cpu temperature and cooling fan status and to
817 control the fans on the I8K portables.
819 This driver has been tested only on the Inspiron 8000 but it may
820 also work with other Dell laptops. You can force loading on other
821 models by passing the parameter `force=1' to the module. Use at
824 For information on utilities to make use of this driver see the
825 I8K Linux utilities web site at:
826 <http://people.debian.org/~dz/i8k/>
828 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
831 config X86_REBOOTFIXUPS
832 bool "Enable X86 board specific fixups for reboot"
835 This enables chipset and/or board specific fixups to be done
836 in order to get reboot to work correctly. This is only needed on
837 some combinations of hardware and BIOS. The symptom, for which
838 this config is intended, is when reboot ends with a stalled/hung
841 Currently, the only fixup is for the Geode machines using
842 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
844 Say Y if you want to enable the fixup. Currently, it's safe to
845 enable this option even if you don't need it.
849 tristate "/dev/cpu/microcode - microcode support"
852 If you say Y here, you will be able to update the microcode on
853 certain Intel and AMD processors. The Intel support is for the
854 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
855 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
856 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
857 You will obviously need the actual microcode binary data itself
858 which is not shipped with the Linux kernel.
860 This option selects the general module only, you need to select
861 at least one vendor specific module as well.
863 To compile this driver as a module, choose M here: the
864 module will be called microcode.
866 config MICROCODE_INTEL
867 bool "Intel microcode patch loading support"
872 This options enables microcode patch loading support for Intel
875 For latest news and information on obtaining all the required
876 Intel ingredients for this driver, check:
877 <http://www.urbanmyth.org/microcode/>.
880 bool "AMD microcode patch loading support"
884 If you select this option, microcode patch loading support for AMD
885 processors will be enabled.
887 config MICROCODE_OLD_INTERFACE
892 tristate "/dev/cpu/*/msr - Model-specific register support"
894 This device gives privileged processes access to the x86
895 Model-Specific Registers (MSRs). It is a character device with
896 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
897 MSR accesses are directed to a specific CPU on multi-processor
901 tristate "/dev/cpu/*/cpuid - CPU information support"
903 This device gives processes access to the x86 CPUID instruction to
904 be executed on a specific processor. It is a character device
905 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
909 prompt "High Memory Support"
910 default HIGHMEM4G if !X86_NUMAQ
911 default HIGHMEM64G if X86_NUMAQ
916 depends on !X86_NUMAQ
918 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
919 However, the address space of 32-bit x86 processors is only 4
920 Gigabytes large. That means that, if you have a large amount of
921 physical memory, not all of it can be "permanently mapped" by the
922 kernel. The physical memory that's not permanently mapped is called
925 If you are compiling a kernel which will never run on a machine with
926 more than 1 Gigabyte total physical RAM, answer "off" here (default
927 choice and suitable for most users). This will result in a "3GB/1GB"
928 split: 3GB are mapped so that each process sees a 3GB virtual memory
929 space and the remaining part of the 4GB virtual memory space is used
930 by the kernel to permanently map as much physical memory as
933 If the machine has between 1 and 4 Gigabytes physical RAM, then
936 If more than 4 Gigabytes is used then answer "64GB" here. This
937 selection turns Intel PAE (Physical Address Extension) mode on.
938 PAE implements 3-level paging on IA32 processors. PAE is fully
939 supported by Linux, PAE mode is implemented on all recent Intel
940 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
941 then the kernel will not boot on CPUs that don't support PAE!
943 The actual amount of total physical memory will either be
944 auto detected or can be forced by using a kernel command line option
945 such as "mem=256M". (Try "man bootparam" or see the documentation of
946 your boot loader (lilo or loadlin) about how to pass options to the
947 kernel at boot time.)
949 If unsure, say "off".
953 depends on !X86_NUMAQ
955 Select this if you have a 32-bit processor and between 1 and 4
956 gigabytes of physical RAM.
960 depends on !M386 && !M486
963 Select this if you have a 32-bit processor and more than 4
964 gigabytes of physical RAM.
969 depends on EXPERIMENTAL
970 prompt "Memory split" if EMBEDDED
974 Select the desired split between kernel and user memory.
976 If the address range available to the kernel is less than the
977 physical memory installed, the remaining memory will be available
978 as "high memory". Accessing high memory is a little more costly
979 than low memory, as it needs to be mapped into the kernel first.
980 Note that increasing the kernel address space limits the range
981 available to user programs, making the address space there
982 tighter. Selecting anything other than the default 3G/1G split
983 will also likely make your kernel incompatible with binary-only
986 If you are not absolutely sure what you are doing, leave this
990 bool "3G/1G user/kernel split"
991 config VMSPLIT_3G_OPT
993 bool "3G/1G user/kernel split (for full 1G low memory)"
995 bool "2G/2G user/kernel split"
996 config VMSPLIT_2G_OPT
998 bool "2G/2G user/kernel split (for full 2G low memory)"
1000 bool "1G/3G user/kernel split"
1005 default 0xB0000000 if VMSPLIT_3G_OPT
1006 default 0x80000000 if VMSPLIT_2G
1007 default 0x78000000 if VMSPLIT_2G_OPT
1008 default 0x40000000 if VMSPLIT_1G
1014 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1017 bool "PAE (Physical Address Extension) Support"
1018 depends on X86_32 && !HIGHMEM4G
1020 PAE is required for NX support, and furthermore enables
1021 larger swapspace support for non-overcommit purposes. It
1022 has the cost of more pagetable lookup overhead, and also
1023 consumes more pagetable space per process.
1025 config ARCH_PHYS_ADDR_T_64BIT
1026 def_bool X86_64 || X86_PAE
1028 config DIRECT_GBPAGES
1029 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1033 Allow the kernel linear mapping to use 1GB pages on CPUs that
1034 support it. This can improve the kernel's performance a tiny bit by
1035 reducing TLB pressure. If in doubt, say "Y".
1037 # Common NUMA Features
1039 bool "Numa Memory Allocation and Scheduler Support"
1041 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1043 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1045 Enable NUMA (Non Uniform Memory Access) support.
1047 The kernel will try to allocate memory used by a CPU on the
1048 local memory controller of the CPU and add some more
1049 NUMA awareness to the kernel.
1051 For 64-bit this is recommended if the system is Intel Core i7
1052 (or later), AMD Opteron, or EM64T NUMA.
1054 For 32-bit this is only needed on (rare) 32-bit-only platforms
1055 that support NUMA topologies, such as NUMAQ / Summit, or if you
1056 boot a 32-bit kernel on a 64-bit NUMA platform.
1058 Otherwise, you should say N.
1060 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1061 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1065 prompt "Old style AMD Opteron NUMA detection"
1066 depends on X86_64 && NUMA && PCI
1068 Enable K8 NUMA node topology detection. You should say Y here if
1069 you have a multi processor AMD K8 system. This uses an old
1070 method to read the NUMA configuration directly from the builtin
1071 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1072 instead, which also takes priority if both are compiled in.
1074 config X86_64_ACPI_NUMA
1076 prompt "ACPI NUMA detection"
1077 depends on X86_64 && NUMA && ACPI && PCI
1080 Enable ACPI SRAT based node topology detection.
1082 # Some NUMA nodes have memory ranges that span
1083 # other nodes. Even though a pfn is valid and
1084 # between a node's start and end pfns, it may not
1085 # reside on that node. See memmap_init_zone()
1087 config NODES_SPAN_OTHER_NODES
1089 depends on X86_64_ACPI_NUMA
1092 bool "NUMA emulation"
1093 depends on X86_64 && NUMA
1095 Enable NUMA emulation. A flat machine will be split
1096 into virtual nodes when booted with "numa=fake=N", where N is the
1097 number of nodes. This is only useful for debugging.
1100 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1102 default "9" if MAXSMP
1103 default "6" if X86_64
1104 default "4" if X86_NUMAQ
1106 depends on NEED_MULTIPLE_NODES
1108 Specify the maximum number of NUMA Nodes available on the target
1109 system. Increases memory reserved to accomodate various tables.
1111 config HAVE_ARCH_BOOTMEM_NODE
1113 depends on X86_32 && NUMA
1115 config ARCH_HAVE_MEMORY_PRESENT
1117 depends on X86_32 && DISCONTIGMEM
1119 config NEED_NODE_MEMMAP_SIZE
1121 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1123 config HAVE_ARCH_ALLOC_REMAP
1125 depends on X86_32 && NUMA
1127 config ARCH_FLATMEM_ENABLE
1129 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1131 config ARCH_DISCONTIGMEM_ENABLE
1133 depends on NUMA && X86_32
1135 config ARCH_DISCONTIGMEM_DEFAULT
1137 depends on NUMA && X86_32
1139 config ARCH_SPARSEMEM_DEFAULT
1143 config ARCH_SPARSEMEM_ENABLE
1145 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_PC) || X86_GENERICARCH
1146 select SPARSEMEM_STATIC if X86_32
1147 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1149 config ARCH_SELECT_MEMORY_MODEL
1151 depends on ARCH_SPARSEMEM_ENABLE
1153 config ARCH_MEMORY_PROBE
1155 depends on MEMORY_HOTPLUG
1160 bool "Allocate 3rd-level pagetables from highmem"
1161 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1163 The VM uses one page table entry for each page of physical memory.
1164 For systems with a lot of RAM, this can be wasteful of precious
1165 low memory. Setting this option will put user-space page table
1166 entries in high memory.
1168 config X86_CHECK_BIOS_CORRUPTION
1169 bool "Check for low memory corruption"
1171 Periodically check for memory corruption in low memory, which
1172 is suspected to be caused by BIOS. Even when enabled in the
1173 configuration, it is disabled at runtime. Enable it by
1174 setting "memory_corruption_check=1" on the kernel command
1175 line. By default it scans the low 64k of memory every 60
1176 seconds; see the memory_corruption_check_size and
1177 memory_corruption_check_period parameters in
1178 Documentation/kernel-parameters.txt to adjust this.
1180 When enabled with the default parameters, this option has
1181 almost no overhead, as it reserves a relatively small amount
1182 of memory and scans it infrequently. It both detects corruption
1183 and prevents it from affecting the running system.
1185 It is, however, intended as a diagnostic tool; if repeatable
1186 BIOS-originated corruption always affects the same memory,
1187 you can use memmap= to prevent the kernel from using that
1190 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1191 bool "Set the default setting of memory_corruption_check"
1192 depends on X86_CHECK_BIOS_CORRUPTION
1195 Set whether the default state of memory_corruption_check is
1198 config X86_RESERVE_LOW_64K
1199 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1202 Reserve the first 64K of physical RAM on BIOSes that are known
1203 to potentially corrupt that memory range. A numbers of BIOSes are
1204 known to utilize this area during suspend/resume, so it must not
1205 be used by the kernel.
1207 Set this to N if you are absolutely sure that you trust the BIOS
1208 to get all its memory reservations and usages right.
1210 If you have doubts about the BIOS (e.g. suspend/resume does not
1211 work or there's kernel crashes after certain hardware hotplug
1212 events) and it's not AMI or Phoenix, then you might want to enable
1213 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1214 corruption patterns.
1218 config MATH_EMULATION
1220 prompt "Math emulation" if X86_32
1222 Linux can emulate a math coprocessor (used for floating point
1223 operations) if you don't have one. 486DX and Pentium processors have
1224 a math coprocessor built in, 486SX and 386 do not, unless you added
1225 a 487DX or 387, respectively. (The messages during boot time can
1226 give you some hints here ["man dmesg"].) Everyone needs either a
1227 coprocessor or this emulation.
1229 If you don't have a math coprocessor, you need to say Y here; if you
1230 say Y here even though you have a coprocessor, the coprocessor will
1231 be used nevertheless. (This behavior can be changed with the kernel
1232 command line option "no387", which comes handy if your coprocessor
1233 is broken. Try "man bootparam" or see the documentation of your boot
1234 loader (lilo or loadlin) about how to pass options to the kernel at
1235 boot time.) This means that it is a good idea to say Y here if you
1236 intend to use this kernel on different machines.
1238 More information about the internals of the Linux math coprocessor
1239 emulation can be found in <file:arch/x86/math-emu/README>.
1241 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1242 kernel, it won't hurt.
1245 bool "MTRR (Memory Type Range Register) support"
1247 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1248 the Memory Type Range Registers (MTRRs) may be used to control
1249 processor access to memory ranges. This is most useful if you have
1250 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1251 allows bus write transfers to be combined into a larger transfer
1252 before bursting over the PCI/AGP bus. This can increase performance
1253 of image write operations 2.5 times or more. Saying Y here creates a
1254 /proc/mtrr file which may be used to manipulate your processor's
1255 MTRRs. Typically the X server should use this.
1257 This code has a reasonably generic interface so that similar
1258 control registers on other processors can be easily supported
1261 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1262 Registers (ARRs) which provide a similar functionality to MTRRs. For
1263 these, the ARRs are used to emulate the MTRRs.
1264 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1265 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1266 write-combining. All of these processors are supported by this code
1267 and it makes sense to say Y here if you have one of them.
1269 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1270 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1271 can lead to all sorts of problems, so it's good to say Y here.
1273 You can safely say Y even if your machine doesn't have MTRRs, you'll
1274 just add about 9 KB to your kernel.
1276 See <file:Documentation/x86/mtrr.txt> for more information.
1278 config MTRR_SANITIZER
1280 prompt "MTRR cleanup support"
1283 Convert MTRR layout from continuous to discrete, so X drivers can
1284 add writeback entries.
1286 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1287 The largest mtrr entry size for a continous block can be set with
1292 config MTRR_SANITIZER_ENABLE_DEFAULT
1293 int "MTRR cleanup enable value (0-1)"
1296 depends on MTRR_SANITIZER
1298 Enable mtrr cleanup default value
1300 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1301 int "MTRR cleanup spare reg num (0-7)"
1304 depends on MTRR_SANITIZER
1306 mtrr cleanup spare entries default, it can be changed via
1307 mtrr_spare_reg_nr=N on the kernel command line.
1311 prompt "x86 PAT support"
1314 Use PAT attributes to setup page level cache control.
1316 PATs are the modern equivalents of MTRRs and are much more
1317 flexible than MTRRs.
1319 Say N here if you see bootup problems (boot crash, boot hang,
1320 spontaneous reboots) or a non-working video driver.
1325 bool "EFI runtime service support"
1328 This enables the kernel to use EFI runtime services that are
1329 available (such as the EFI variable services).
1331 This option is only useful on systems that have EFI firmware.
1332 In addition, you should use the latest ELILO loader available
1333 at <http://elilo.sourceforge.net> in order to take advantage
1334 of EFI runtime services. However, even with this option, the
1335 resultant kernel should continue to boot on existing non-EFI
1340 prompt "Enable seccomp to safely compute untrusted bytecode"
1342 This kernel feature is useful for number crunching applications
1343 that may need to compute untrusted bytecode during their
1344 execution. By using pipes or other transports made available to
1345 the process as file descriptors supporting the read/write
1346 syscalls, it's possible to isolate those applications in
1347 their own address space using seccomp. Once seccomp is
1348 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1349 and the task is only allowed to execute a few safe syscalls
1350 defined by each seccomp mode.
1352 If unsure, say Y. Only embedded should say N here.
1354 config CC_STACKPROTECTOR_ALL
1357 config CC_STACKPROTECTOR
1358 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1359 select CC_STACKPROTECTOR_ALL
1361 This option turns on the -fstack-protector GCC feature. This
1362 feature puts, at the beginning of functions, a canary value on
1363 the stack just before the return address, and validates
1364 the value just before actually returning. Stack based buffer
1365 overflows (that need to overwrite this return address) now also
1366 overwrite the canary, which gets detected and the attack is then
1367 neutralized via a kernel panic.
1369 This feature requires gcc version 4.2 or above, or a distribution
1370 gcc with the feature backported. Older versions are automatically
1371 detected and for those versions, this configuration option is
1372 ignored. (and a warning is printed during bootup)
1374 source kernel/Kconfig.hz
1377 bool "kexec system call"
1378 depends on X86_BIOS_REBOOT
1380 kexec is a system call that implements the ability to shutdown your
1381 current kernel, and to start another kernel. It is like a reboot
1382 but it is independent of the system firmware. And like a reboot
1383 you can start any kernel with it, not just Linux.
1385 The name comes from the similarity to the exec system call.
1387 It is an ongoing process to be certain the hardware in a machine
1388 is properly shutdown, so do not be surprised if this code does not
1389 initially work for you. It may help to enable device hotplugging
1390 support. As of this writing the exact hardware interface is
1391 strongly in flux, so no good recommendation can be made.
1394 bool "kernel crash dumps"
1395 depends on X86_64 || (X86_32 && HIGHMEM)
1397 Generate crash dump after being started by kexec.
1398 This should be normally only set in special crash dump kernels
1399 which are loaded in the main kernel with kexec-tools into
1400 a specially reserved region and then later executed after
1401 a crash by kdump/kexec. The crash dump kernel must be compiled
1402 to a memory address not used by the main kernel or BIOS using
1403 PHYSICAL_START, or it must be built as a relocatable image
1404 (CONFIG_RELOCATABLE=y).
1405 For more details see Documentation/kdump/kdump.txt
1408 bool "kexec jump (EXPERIMENTAL)"
1409 depends on EXPERIMENTAL
1410 depends on KEXEC && HIBERNATION && X86_32
1412 Jump between original kernel and kexeced kernel and invoke
1413 code in physical address mode via KEXEC
1415 config PHYSICAL_START
1416 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1417 default "0x1000000" if X86_NUMAQ
1418 default "0x200000" if X86_64
1421 This gives the physical address where the kernel is loaded.
1423 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1424 bzImage will decompress itself to above physical address and
1425 run from there. Otherwise, bzImage will run from the address where
1426 it has been loaded by the boot loader and will ignore above physical
1429 In normal kdump cases one does not have to set/change this option
1430 as now bzImage can be compiled as a completely relocatable image
1431 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1432 address. This option is mainly useful for the folks who don't want
1433 to use a bzImage for capturing the crash dump and want to use a
1434 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1435 to be specifically compiled to run from a specific memory area
1436 (normally a reserved region) and this option comes handy.
1438 So if you are using bzImage for capturing the crash dump, leave
1439 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1440 Otherwise if you plan to use vmlinux for capturing the crash dump
1441 change this value to start of the reserved region (Typically 16MB
1442 0x1000000). In other words, it can be set based on the "X" value as
1443 specified in the "crashkernel=YM@XM" command line boot parameter
1444 passed to the panic-ed kernel. Typically this parameter is set as
1445 crashkernel=64M@16M. Please take a look at
1446 Documentation/kdump/kdump.txt for more details about crash dumps.
1448 Usage of bzImage for capturing the crash dump is recommended as
1449 one does not have to build two kernels. Same kernel can be used
1450 as production kernel and capture kernel. Above option should have
1451 gone away after relocatable bzImage support is introduced. But it
1452 is present because there are users out there who continue to use
1453 vmlinux for dump capture. This option should go away down the
1456 Don't change this unless you know what you are doing.
1459 bool "Build a relocatable kernel (EXPERIMENTAL)"
1460 depends on EXPERIMENTAL
1462 This builds a kernel image that retains relocation information
1463 so it can be loaded someplace besides the default 1MB.
1464 The relocations tend to make the kernel binary about 10% larger,
1465 but are discarded at runtime.
1467 One use is for the kexec on panic case where the recovery kernel
1468 must live at a different physical address than the primary
1471 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1472 it has been loaded at and the compile time physical address
1473 (CONFIG_PHYSICAL_START) is ignored.
1475 config PHYSICAL_ALIGN
1477 prompt "Alignment value to which kernel should be aligned" if X86_32
1478 default "0x100000" if X86_32
1479 default "0x200000" if X86_64
1480 range 0x2000 0x400000
1482 This value puts the alignment restrictions on physical address
1483 where kernel is loaded and run from. Kernel is compiled for an
1484 address which meets above alignment restriction.
1486 If bootloader loads the kernel at a non-aligned address and
1487 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1488 address aligned to above value and run from there.
1490 If bootloader loads the kernel at a non-aligned address and
1491 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1492 load address and decompress itself to the address it has been
1493 compiled for and run from there. The address for which kernel is
1494 compiled already meets above alignment restrictions. Hence the
1495 end result is that kernel runs from a physical address meeting
1496 above alignment restrictions.
1498 Don't change this unless you know what you are doing.
1501 bool "Support for hot-pluggable CPUs"
1502 depends on SMP && HOTPLUG && !X86_VOYAGER
1504 Say Y here to allow turning CPUs off and on. CPUs can be
1505 controlled through /sys/devices/system/cpu.
1506 ( Note: power management support will enable this option
1507 automatically on SMP systems. )
1508 Say N if you want to disable CPU hotplug.
1512 prompt "Compat VDSO support"
1513 depends on X86_32 || IA32_EMULATION
1515 Map the 32-bit VDSO to the predictable old-style address too.
1517 Say N here if you are running a sufficiently recent glibc
1518 version (2.3.3 or later), to remove the high-mapped
1519 VDSO mapping and to exclusively use the randomized VDSO.
1524 bool "Built-in kernel command line"
1527 Allow for specifying boot arguments to the kernel at
1528 build time. On some systems (e.g. embedded ones), it is
1529 necessary or convenient to provide some or all of the
1530 kernel boot arguments with the kernel itself (that is,
1531 to not rely on the boot loader to provide them.)
1533 To compile command line arguments into the kernel,
1534 set this option to 'Y', then fill in the
1535 the boot arguments in CONFIG_CMDLINE.
1537 Systems with fully functional boot loaders (i.e. non-embedded)
1538 should leave this option set to 'N'.
1541 string "Built-in kernel command string"
1542 depends on CMDLINE_BOOL
1545 Enter arguments here that should be compiled into the kernel
1546 image and used at boot time. If the boot loader provides a
1547 command line at boot time, it is appended to this string to
1548 form the full kernel command line, when the system boots.
1550 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1551 change this behavior.
1553 In most cases, the command line (whether built-in or provided
1554 by the boot loader) should specify the device for the root
1557 config CMDLINE_OVERRIDE
1558 bool "Built-in command line overrides boot loader arguments"
1560 depends on CMDLINE_BOOL
1562 Set this option to 'Y' to have the kernel ignore the boot loader
1563 command line, and use ONLY the built-in command line.
1565 This is used to work around broken boot loaders. This should
1566 be set to 'N' under normal conditions.
1570 config ARCH_ENABLE_MEMORY_HOTPLUG
1572 depends on X86_64 || (X86_32 && HIGHMEM)
1574 config ARCH_ENABLE_MEMORY_HOTREMOVE
1576 depends on MEMORY_HOTPLUG
1578 config HAVE_ARCH_EARLY_PFN_TO_NID
1582 menu "Power management and ACPI options"
1583 depends on !X86_VOYAGER
1585 config ARCH_HIBERNATION_HEADER
1587 depends on X86_64 && HIBERNATION
1589 source "kernel/power/Kconfig"
1591 source "drivers/acpi/Kconfig"
1596 depends on APM || APM_MODULE
1599 tristate "APM (Advanced Power Management) BIOS support"
1600 depends on X86_32 && PM_SLEEP
1602 APM is a BIOS specification for saving power using several different
1603 techniques. This is mostly useful for battery powered laptops with
1604 APM compliant BIOSes. If you say Y here, the system time will be
1605 reset after a RESUME operation, the /proc/apm device will provide
1606 battery status information, and user-space programs will receive
1607 notification of APM "events" (e.g. battery status change).
1609 If you select "Y" here, you can disable actual use of the APM
1610 BIOS by passing the "apm=off" option to the kernel at boot time.
1612 Note that the APM support is almost completely disabled for
1613 machines with more than one CPU.
1615 In order to use APM, you will need supporting software. For location
1616 and more information, read <file:Documentation/power/pm.txt> and the
1617 Battery Powered Linux mini-HOWTO, available from
1618 <http://www.tldp.org/docs.html#howto>.
1620 This driver does not spin down disk drives (see the hdparm(8)
1621 manpage ("man 8 hdparm") for that), and it doesn't turn off
1622 VESA-compliant "green" monitors.
1624 This driver does not support the TI 4000M TravelMate and the ACER
1625 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1626 desktop machines also don't have compliant BIOSes, and this driver
1627 may cause those machines to panic during the boot phase.
1629 Generally, if you don't have a battery in your machine, there isn't
1630 much point in using this driver and you should say N. If you get
1631 random kernel OOPSes or reboots that don't seem to be related to
1632 anything, try disabling/enabling this option (or disabling/enabling
1635 Some other things you should try when experiencing seemingly random,
1638 1) make sure that you have enough swap space and that it is
1640 2) pass the "no-hlt" option to the kernel
1641 3) switch on floating point emulation in the kernel and pass
1642 the "no387" option to the kernel
1643 4) pass the "floppy=nodma" option to the kernel
1644 5) pass the "mem=4M" option to the kernel (thereby disabling
1645 all but the first 4 MB of RAM)
1646 6) make sure that the CPU is not over clocked.
1647 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1648 8) disable the cache from your BIOS settings
1649 9) install a fan for the video card or exchange video RAM
1650 10) install a better fan for the CPU
1651 11) exchange RAM chips
1652 12) exchange the motherboard.
1654 To compile this driver as a module, choose M here: the
1655 module will be called apm.
1659 config APM_IGNORE_USER_SUSPEND
1660 bool "Ignore USER SUSPEND"
1662 This option will ignore USER SUSPEND requests. On machines with a
1663 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1664 series notebooks, it is necessary to say Y because of a BIOS bug.
1666 config APM_DO_ENABLE
1667 bool "Enable PM at boot time"
1669 Enable APM features at boot time. From page 36 of the APM BIOS
1670 specification: "When disabled, the APM BIOS does not automatically
1671 power manage devices, enter the Standby State, enter the Suspend
1672 State, or take power saving steps in response to CPU Idle calls."
1673 This driver will make CPU Idle calls when Linux is idle (unless this
1674 feature is turned off -- see "Do CPU IDLE calls", below). This
1675 should always save battery power, but more complicated APM features
1676 will be dependent on your BIOS implementation. You may need to turn
1677 this option off if your computer hangs at boot time when using APM
1678 support, or if it beeps continuously instead of suspending. Turn
1679 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1680 T400CDT. This is off by default since most machines do fine without
1684 bool "Make CPU Idle calls when idle"
1686 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1687 On some machines, this can activate improved power savings, such as
1688 a slowed CPU clock rate, when the machine is idle. These idle calls
1689 are made after the idle loop has run for some length of time (e.g.,
1690 333 mS). On some machines, this will cause a hang at boot time or
1691 whenever the CPU becomes idle. (On machines with more than one CPU,
1692 this option does nothing.)
1694 config APM_DISPLAY_BLANK
1695 bool "Enable console blanking using APM"
1697 Enable console blanking using the APM. Some laptops can use this to
1698 turn off the LCD backlight when the screen blanker of the Linux
1699 virtual console blanks the screen. Note that this is only used by
1700 the virtual console screen blanker, and won't turn off the backlight
1701 when using the X Window system. This also doesn't have anything to
1702 do with your VESA-compliant power-saving monitor. Further, this
1703 option doesn't work for all laptops -- it might not turn off your
1704 backlight at all, or it might print a lot of errors to the console,
1705 especially if you are using gpm.
1707 config APM_ALLOW_INTS
1708 bool "Allow interrupts during APM BIOS calls"
1710 Normally we disable external interrupts while we are making calls to
1711 the APM BIOS as a measure to lessen the effects of a badly behaving
1712 BIOS implementation. The BIOS should reenable interrupts if it
1713 needs to. Unfortunately, some BIOSes do not -- especially those in
1714 many of the newer IBM Thinkpads. If you experience hangs when you
1715 suspend, try setting this to Y. Otherwise, say N.
1719 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1721 source "drivers/cpuidle/Kconfig"
1723 source "drivers/idle/Kconfig"
1728 menu "Bus options (PCI etc.)"
1733 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1735 Find out whether you have a PCI motherboard. PCI is the name of a
1736 bus system, i.e. the way the CPU talks to the other stuff inside
1737 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1738 VESA. If you have PCI, say Y, otherwise N.
1741 prompt "PCI access mode"
1742 depends on X86_32 && PCI
1745 On PCI systems, the BIOS can be used to detect the PCI devices and
1746 determine their configuration. However, some old PCI motherboards
1747 have BIOS bugs and may crash if this is done. Also, some embedded
1748 PCI-based systems don't have any BIOS at all. Linux can also try to
1749 detect the PCI hardware directly without using the BIOS.
1751 With this option, you can specify how Linux should detect the
1752 PCI devices. If you choose "BIOS", the BIOS will be used,
1753 if you choose "Direct", the BIOS won't be used, and if you
1754 choose "MMConfig", then PCI Express MMCONFIG will be used.
1755 If you choose "Any", the kernel will try MMCONFIG, then the
1756 direct access method and falls back to the BIOS if that doesn't
1757 work. If unsure, go with the default, which is "Any".
1762 config PCI_GOMMCONFIG
1779 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1781 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1784 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1788 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1792 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1799 bool "Support mmconfig PCI config space access"
1800 depends on X86_64 && PCI && ACPI
1803 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1804 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1806 DMA remapping (DMAR) devices support enables independent address
1807 translations for Direct Memory Access (DMA) from devices.
1808 These DMA remapping devices are reported via ACPI tables
1809 and include PCI device scope covered by these DMA
1812 config DMAR_DEFAULT_ON
1814 prompt "Enable DMA Remapping Devices by default"
1817 Selecting this option will enable a DMAR device at boot time if
1818 one is found. If this option is not selected, DMAR support can
1819 be enabled by passing intel_iommu=on to the kernel. It is
1820 recommended you say N here while the DMAR code remains
1825 prompt "Support for Graphics workaround"
1828 Current Graphics drivers tend to use physical address
1829 for DMA and avoid using DMA APIs. Setting this config
1830 option permits the IOMMU driver to set a unity map for
1831 all the OS-visible memory. Hence the driver can continue
1832 to use physical addresses for DMA.
1834 config DMAR_FLOPPY_WA
1838 Floppy disk drivers are know to bypass DMA API calls
1839 thereby failing to work when IOMMU is enabled. This
1840 workaround will setup a 1:1 mapping for the first
1841 16M to make floppy (an ISA device) work.
1844 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1845 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1847 Supports Interrupt remapping for IO-APIC and MSI devices.
1848 To use x2apic mode in the CPU's which support x2APIC enhancements or
1849 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1851 source "drivers/pci/pcie/Kconfig"
1853 source "drivers/pci/Kconfig"
1855 # x86_64 have no ISA slots, but do have ISA-style DMA.
1863 depends on !X86_VOYAGER
1865 Find out whether you have ISA slots on your motherboard. ISA is the
1866 name of a bus system, i.e. the way the CPU talks to the other stuff
1867 inside your box. Other bus systems are PCI, EISA, MicroChannel
1868 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1869 newer boards don't support it. If you have ISA, say Y, otherwise N.
1875 The Extended Industry Standard Architecture (EISA) bus was
1876 developed as an open alternative to the IBM MicroChannel bus.
1878 The EISA bus provided some of the features of the IBM MicroChannel
1879 bus while maintaining backward compatibility with cards made for
1880 the older ISA bus. The EISA bus saw limited use between 1988 and
1881 1995 when it was made obsolete by the PCI bus.
1883 Say Y here if you are building a kernel for an EISA-based machine.
1887 source "drivers/eisa/Kconfig"
1890 bool "MCA support" if !X86_VOYAGER
1891 default y if X86_VOYAGER
1893 MicroChannel Architecture is found in some IBM PS/2 machines and
1894 laptops. It is a bus system similar to PCI or ISA. See
1895 <file:Documentation/mca.txt> (and especially the web page given
1896 there) before attempting to build an MCA bus kernel.
1898 source "drivers/mca/Kconfig"
1901 tristate "NatSemi SCx200 support"
1902 depends on !X86_VOYAGER
1904 This provides basic support for National Semiconductor's
1905 (now AMD's) Geode processors. The driver probes for the
1906 PCI-IDs of several on-chip devices, so its a good dependency
1907 for other scx200_* drivers.
1909 If compiled as a module, the driver is named scx200.
1911 config SCx200HR_TIMER
1912 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1913 depends on SCx200 && GENERIC_TIME
1916 This driver provides a clocksource built upon the on-chip
1917 27MHz high-resolution timer. Its also a workaround for
1918 NSC Geode SC-1100's buggy TSC, which loses time when the
1919 processor goes idle (as is done by the scheduler). The
1920 other workaround is idle=poll boot option.
1922 config GEODE_MFGPT_TIMER
1924 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1925 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1927 This driver provides a clock event source based on the MFGPT
1928 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1929 MFGPTs have a better resolution and max interval than the
1930 generic PIT, and are suitable for use as high-res timers.
1933 bool "One Laptop Per Child support"
1936 Add support for detecting the unique features of the OLPC
1943 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1945 source "drivers/pcmcia/Kconfig"
1947 source "drivers/pci/hotplug/Kconfig"
1952 menu "Executable file formats / Emulations"
1954 source "fs/Kconfig.binfmt"
1956 config IA32_EMULATION
1957 bool "IA32 Emulation"
1959 select COMPAT_BINFMT_ELF
1961 Include code to run 32-bit programs under a 64-bit kernel. You should
1962 likely turn this on, unless you're 100% sure that you don't have any
1963 32-bit programs left.
1966 tristate "IA32 a.out support"
1967 depends on IA32_EMULATION
1969 Support old a.out binaries in the 32bit emulation.
1973 depends on IA32_EMULATION
1975 config COMPAT_FOR_U64_ALIGNMENT
1979 config SYSVIPC_COMPAT
1981 depends on COMPAT && SYSVIPC
1986 config HAVE_ATOMIC_IOMAP
1990 source "net/Kconfig"
1992 source "drivers/Kconfig"
1994 source "drivers/firmware/Kconfig"
1998 source "arch/x86/Kconfig.debug"
2000 source "security/Kconfig"
2002 source "crypto/Kconfig"
2004 source "arch/x86/kvm/Kconfig"
2006 source "lib/Kconfig"
projects / firefly-linux-kernel-4.4.55.git / blob