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
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
144 config ARCH_SUSPEND_POSSIBLE
151 config ARCH_POPULATES_NODE_MAP
158 config ARCH_SUPPORTS_OPTIMIZED_INLINING
161 # Use the generic interrupt handling code in kernel/irq/:
162 config GENERIC_HARDIRQS
166 config GENERIC_IRQ_PROBE
170 config GENERIC_PENDING_IRQ
172 depends on GENERIC_HARDIRQS && SMP
175 config USE_GENERIC_SMP_HELPERS
181 depends on X86_32 && SMP
185 depends on X86_64 && SMP
192 config X86_TRAMPOLINE
194 depends on SMP || (64BIT && ACPI_SLEEP)
197 config X86_32_LAZY_GS
199 depends on X86_32 && !CC_STACKPROTECTOR
203 source "init/Kconfig"
204 source "kernel/Kconfig.freezer"
206 menu "Processor type and features"
208 source "kernel/time/Kconfig"
211 bool "Symmetric multi-processing support"
213 This enables support for systems with more than one CPU. If you have
214 a system with only one CPU, like most personal computers, say N. If
215 you have a system with more than one CPU, say Y.
217 If you say N here, the kernel will run on single and multiprocessor
218 machines, but will use only one CPU of a multiprocessor machine. If
219 you say Y here, the kernel will run on many, but not all,
220 singleprocessor machines. On a singleprocessor machine, the kernel
221 will run faster if you say N here.
223 Note that if you say Y here and choose architecture "586" or
224 "Pentium" under "Processor family", the kernel will not work on 486
225 architectures. Similarly, multiprocessor kernels for the "PPro"
226 architecture may not work on all Pentium based boards.
228 People using multiprocessor machines who say Y here should also say
229 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
230 Management" code will be disabled if you say Y here.
232 See also <file:Documentation/i386/IO-APIC.txt>,
233 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
234 <http://www.tldp.org/docs.html#howto>.
236 If you don't know what to do here, say N.
239 bool "Support sparse irq numbering"
240 depends on PCI_MSI || HT_IRQ
242 This enables support for sparse irqs. This is useful for distro
243 kernels that want to define a high CONFIG_NR_CPUS value but still
244 want to have low kernel memory footprint on smaller machines.
246 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
247 out the irq_desc[] array in a more NUMA-friendly way. )
249 If you don't know what to do here, say N.
251 config NUMA_MIGRATE_IRQ_DESC
252 bool "Move irq desc when changing irq smp_affinity"
253 depends on SPARSE_IRQ && NUMA
256 This enables moving irq_desc to cpu/node that irq will use handled.
258 If you don't know what to do here, say N.
261 bool "Enable MPS table" if ACPI
263 depends on X86_LOCAL_APIC
265 For old smp systems that do not have proper acpi support. Newer systems
266 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
269 bool "Support for big SMP systems with more than 8 CPUs"
270 depends on X86_32 && SMP
272 This option is needed for the systems that have more than 8 CPUs
274 config X86_EXTENDED_PLATFORM
275 bool "Support for extended (non-PC) x86 platforms"
278 If you disable this option then the kernel will only support
279 standard PC platforms. (which covers the vast majority of
282 If you enable this option then you'll be able to select a number
283 of non-PC x86 platforms.
285 If you have one of these systems, or if you want to build a
286 generic distribution kernel, say Y here - otherwise say N.
288 # This is an alphabetically sorted list of 64 bit extended platforms
289 # Please maintain the alphabetic order if and when there are additions
294 depends on X86_64 && PCI
295 depends on X86_EXTENDED_PLATFORM
297 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
298 supposed to run on these EM64T-based machines. Only choose this option
299 if you have one of these machines.
302 bool "SGI Ultraviolet"
304 depends on X86_EXTENDED_PLATFORM
306 This option is needed in order to support SGI Ultraviolet systems.
307 If you don't have one of these, you should say N here.
309 # Following is an alphabetically sorted list of 32 bit extended platforms
310 # Please maintain the alphabetic order if and when there are additions
315 depends on X86_EXTENDED_PLATFORM
317 Select this for an AMD Elan processor.
319 Do not use this option for K6/Athlon/Opteron processors!
321 If unsure, choose "PC-compatible" instead.
324 bool "RDC R-321x SoC"
326 depends on X86_EXTENDED_PLATFORM
328 select X86_REBOOTFIXUPS
330 This option is needed for RDC R-321x system-on-chip, also known
332 If you don't have one of these chips, you should say N here.
334 config X86_32_NON_STANDARD
335 bool "Support non-standard 32-bit SMP architectures"
336 depends on X86_32 && SMP
337 depends on X86_EXTENDED_PLATFORM
339 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
340 subarchitectures. It is intended for a generic binary kernel.
341 if you select them all, kernel will probe it one by one. and will
344 # Alphabetically sorted list of Non standard 32 bit platforms
347 bool "NUMAQ (IBM/Sequent)"
348 depends on X86_32_NON_STANDARD
352 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
353 NUMA multiquad box. This changes the way that processors are
354 bootstrapped, and uses Clustered Logical APIC addressing mode instead
355 of Flat Logical. You will need a new lynxer.elf file to flash your
356 firmware with - send email to <Martin.Bligh@us.ibm.com>.
359 bool "SGI 320/540 (Visual Workstation)"
360 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
361 depends on X86_32_NON_STANDARD
363 The SGI Visual Workstation series is an IA32-based workstation
364 based on SGI systems chips with some legacy PC hardware attached.
366 Say Y here to create a kernel to run on the SGI 320 or 540.
368 A kernel compiled for the Visual Workstation will run on general
369 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
372 bool "Summit/EXA (IBM x440)"
373 depends on X86_32_NON_STANDARD
375 This option is needed for IBM systems that use the Summit/EXA chipset.
376 In particular, it is needed for the x440.
379 bool "Unisys ES7000 IA32 series"
380 depends on X86_32_NON_STANDARD && X86_BIGSMP
382 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
383 supposed to run on an IA32-based Unisys ES7000 system.
387 depends on SMP && !PCI && BROKEN
388 depends on X86_32_NON_STANDARD
390 Voyager is an MCA-based 32-way capable SMP architecture proprietary
391 to NCR Corp. Machine classes 345x/35xx/4100/51xx are Voyager-based.
395 If you do not specifically know you have a Voyager based machine,
396 say N here, otherwise the kernel you build will not be bootable.
398 config SCHED_OMIT_FRAME_POINTER
400 prompt "Single-depth WCHAN output"
403 Calculate simpler /proc/<PID>/wchan values. If this option
404 is disabled then wchan values will recurse back to the
405 caller function. This provides more accurate wchan values,
406 at the expense of slightly more scheduling overhead.
408 If in doubt, say "Y".
410 menuconfig PARAVIRT_GUEST
411 bool "Paravirtualized guest support"
413 Say Y here to get to see options related to running Linux under
414 various hypervisors. This option alone does not add any kernel code.
416 If you say N, all options in this submenu will be skipped and disabled.
420 source "arch/x86/xen/Kconfig"
423 bool "VMI Guest support"
427 VMI provides a paravirtualized interface to the VMware ESX server
428 (it could be used by other hypervisors in theory too, but is not
429 at the moment), by linking the kernel to a GPL-ed ROM module
430 provided by the hypervisor.
433 bool "KVM paravirtualized clock"
435 select PARAVIRT_CLOCK
437 Turning on this option will allow you to run a paravirtualized clock
438 when running over the KVM hypervisor. Instead of relying on a PIT
439 (or probably other) emulation by the underlying device model, the host
440 provides the guest with timing infrastructure such as time of day, and
444 bool "KVM Guest support"
447 This option enables various optimizations for running under the KVM
450 source "arch/x86/lguest/Kconfig"
453 bool "Enable paravirtualization code"
455 This changes the kernel so it can modify itself when it is run
456 under a hypervisor, potentially improving performance significantly
457 over full virtualization. However, when run without a hypervisor
458 the kernel is theoretically slower and slightly larger.
460 config PARAVIRT_CLOCK
466 config PARAVIRT_DEBUG
467 bool "paravirt-ops debugging"
468 depends on PARAVIRT && DEBUG_KERNEL
470 Enable to debug paravirt_ops internals. Specifically, BUG if
471 a paravirt_op is missing when it is called.
476 This option adds a kernel parameter 'memtest', which allows memtest
478 memtest=0, mean disabled; -- default
479 memtest=1, mean do 1 test pattern;
481 memtest=4, mean do 4 test patterns.
482 If you are unsure how to answer this question, answer N.
484 config X86_SUMMIT_NUMA
486 depends on X86_32 && NUMA && X86_32_NON_STANDARD
488 config X86_CYCLONE_TIMER
490 depends on X86_32_NON_STANDARD
492 source "arch/x86/Kconfig.cpu"
496 prompt "HPET Timer Support" if X86_32
498 Use the IA-PC HPET (High Precision Event Timer) to manage
499 time in preference to the PIT and RTC, if a HPET is
501 HPET is the next generation timer replacing legacy 8254s.
502 The HPET provides a stable time base on SMP
503 systems, unlike the TSC, but it is more expensive to access,
504 as it is off-chip. You can find the HPET spec at
505 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
507 You can safely choose Y here. However, HPET will only be
508 activated if the platform and the BIOS support this feature.
509 Otherwise the 8254 will be used for timing services.
511 Choose N to continue using the legacy 8254 timer.
513 config HPET_EMULATE_RTC
515 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
517 # Mark as embedded because too many people got it wrong.
518 # The code disables itself when not needed.
521 bool "Enable DMI scanning" if EMBEDDED
523 Enabled scanning of DMI to identify machine quirks. Say Y
524 here unless you have verified that your setup is not
525 affected by entries in the DMI blacklist. Required by PNP
529 bool "GART IOMMU support" if EMBEDDED
533 depends on X86_64 && PCI
535 Support for full DMA access of devices with 32bit memory access only
536 on systems with more than 3GB. This is usually needed for USB,
537 sound, many IDE/SATA chipsets and some other devices.
538 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
539 based hardware IOMMU and a software bounce buffer based IOMMU used
540 on Intel systems and as fallback.
541 The code is only active when needed (enough memory and limited
542 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
546 bool "IBM Calgary IOMMU support"
548 depends on X86_64 && PCI && EXPERIMENTAL
550 Support for hardware IOMMUs in IBM's xSeries x366 and x460
551 systems. Needed to run systems with more than 3GB of memory
552 properly with 32-bit PCI devices that do not support DAC
553 (Double Address Cycle). Calgary also supports bus level
554 isolation, where all DMAs pass through the IOMMU. This
555 prevents them from going anywhere except their intended
556 destination. This catches hard-to-find kernel bugs and
557 mis-behaving drivers and devices that do not use the DMA-API
558 properly to set up their DMA buffers. The IOMMU can be
559 turned off at boot time with the iommu=off parameter.
560 Normally the kernel will make the right choice by itself.
563 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
565 prompt "Should Calgary be enabled by default?"
566 depends on CALGARY_IOMMU
568 Should Calgary be enabled by default? if you choose 'y', Calgary
569 will be used (if it exists). If you choose 'n', Calgary will not be
570 used even if it exists. If you choose 'n' and would like to use
571 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
575 bool "AMD IOMMU support"
578 depends on X86_64 && PCI && ACPI
580 With this option you can enable support for AMD IOMMU hardware in
581 your system. An IOMMU is a hardware component which provides
582 remapping of DMA memory accesses from devices. With an AMD IOMMU you
583 can isolate the the DMA memory of different devices and protect the
584 system from misbehaving device drivers or hardware.
586 You can find out if your system has an AMD IOMMU if you look into
587 your BIOS for an option to enable it or if you have an IVRS ACPI
590 config AMD_IOMMU_STATS
591 bool "Export AMD IOMMU statistics to debugfs"
595 This option enables code in the AMD IOMMU driver to collect various
596 statistics about whats happening in the driver and exports that
597 information to userspace via debugfs.
600 # need this always selected by IOMMU for the VIA workaround
604 Support for software bounce buffers used on x86-64 systems
605 which don't have a hardware IOMMU (e.g. the current generation
606 of Intel's x86-64 CPUs). Using this PCI devices which can only
607 access 32-bits of memory can be used on systems with more than
608 3 GB of memory. If unsure, say Y.
611 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
614 def_bool (AMD_IOMMU || DMAR)
617 bool "Configure Maximum number of SMP Processors and NUMA Nodes"
618 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
619 select CPUMASK_OFFSTACK
622 Configure maximum number of CPUS and NUMA Nodes for this architecture.
626 int "Maximum number of CPUs" if SMP && !MAXSMP
627 range 2 512 if SMP && !MAXSMP
629 default "4096" if MAXSMP
630 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
633 This allows you to specify the maximum number of CPUs which this
634 kernel will support. The maximum supported value is 512 and the
635 minimum value which makes sense is 2.
637 This is purely to save memory - each supported CPU adds
638 approximately eight kilobytes to the kernel image.
641 bool "SMT (Hyperthreading) scheduler support"
644 SMT scheduler support improves the CPU scheduler's decision making
645 when dealing with Intel Pentium 4 chips with HyperThreading at a
646 cost of slightly increased overhead in some places. If unsure say
651 prompt "Multi-core scheduler support"
654 Multi-core scheduler support improves the CPU scheduler's decision
655 making when dealing with multi-core CPU chips at a cost of slightly
656 increased overhead in some places. If unsure say N here.
658 source "kernel/Kconfig.preempt"
661 bool "Local APIC support on uniprocessors"
662 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
664 A local APIC (Advanced Programmable Interrupt Controller) is an
665 integrated interrupt controller in the CPU. If you have a single-CPU
666 system which has a processor with a local APIC, you can say Y here to
667 enable and use it. If you say Y here even though your machine doesn't
668 have a local APIC, then the kernel will still run with no slowdown at
669 all. The local APIC supports CPU-generated self-interrupts (timer,
670 performance counters), and the NMI watchdog which detects hard
674 bool "IO-APIC support on uniprocessors"
675 depends on X86_UP_APIC
677 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
678 SMP-capable replacement for PC-style interrupt controllers. Most
679 SMP systems and many recent uniprocessor systems have one.
681 If you have a single-CPU system with an IO-APIC, you can say Y here
682 to use it. If you say Y here even though your machine doesn't have
683 an IO-APIC, then the kernel will still run with no slowdown at all.
685 config X86_LOCAL_APIC
687 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
688 select HAVE_PERF_COUNTERS if (!M386 && !M486)
692 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
694 config X86_VISWS_APIC
696 depends on X86_32 && X86_VISWS
698 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
699 bool "Reroute for broken boot IRQs"
701 depends on X86_IO_APIC
703 This option enables a workaround that fixes a source of
704 spurious interrupts. This is recommended when threaded
705 interrupt handling is used on systems where the generation of
706 superfluous "boot interrupts" cannot be disabled.
708 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
709 entry in the chipset's IO-APIC is masked (as, e.g. the RT
710 kernel does during interrupt handling). On chipsets where this
711 boot IRQ generation cannot be disabled, this workaround keeps
712 the original IRQ line masked so that only the equivalent "boot
713 IRQ" is delivered to the CPUs. The workaround also tells the
714 kernel to set up the IRQ handler on the boot IRQ line. In this
715 way only one interrupt is delivered to the kernel. Otherwise
716 the spurious second interrupt may cause the kernel to bring
717 down (vital) interrupt lines.
719 Only affects "broken" chipsets. Interrupt sharing may be
720 increased on these systems.
723 bool "Machine Check Exception"
725 Machine Check Exception support allows the processor to notify the
726 kernel if it detects a problem (e.g. overheating, component failure).
727 The action the kernel takes depends on the severity of the problem,
728 ranging from a warning message on the console, to halting the machine.
729 Your processor must be a Pentium or newer to support this - check the
730 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
731 have a design flaw which leads to false MCE events - hence MCE is
732 disabled on all P5 processors, unless explicitly enabled with "mce"
733 as a boot argument. Similarly, if MCE is built in and creates a
734 problem on some new non-standard machine, you can boot with "nomce"
735 to disable it. MCE support simply ignores non-MCE processors like
736 the 386 and 486, so nearly everyone can say Y here.
740 prompt "Intel MCE features"
741 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
743 Additional support for intel specific MCE features such as
748 prompt "AMD MCE features"
749 depends on X86_64 && X86_MCE && X86_LOCAL_APIC
751 Additional support for AMD specific MCE features such as
752 the DRAM Error Threshold.
754 config X86_MCE_NONFATAL
755 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
756 depends on X86_32 && X86_MCE
758 Enabling this feature starts a timer that triggers every 5 seconds which
759 will look at the machine check registers to see if anything happened.
760 Non-fatal problems automatically get corrected (but still logged).
761 Disable this if you don't want to see these messages.
762 Seeing the messages this option prints out may be indicative of dying
763 or out-of-spec (ie, overclocked) hardware.
764 This option only does something on certain CPUs.
765 (AMD Athlon/Duron and Intel Pentium 4)
767 config X86_MCE_P4THERMAL
768 bool "check for P4 thermal throttling interrupt."
769 depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
771 Enabling this feature will cause a message to be printed when the P4
772 enters thermal throttling.
775 bool "Enable VM86 support" if EMBEDDED
779 This option is required by programs like DOSEMU to run 16-bit legacy
780 code on X86 processors. It also may be needed by software like
781 XFree86 to initialize some video cards via BIOS. Disabling this
782 option saves about 6k.
785 tristate "Toshiba Laptop support"
788 This adds a driver to safely access the System Management Mode of
789 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
790 not work on models with a Phoenix BIOS. The System Management Mode
791 is used to set the BIOS and power saving options on Toshiba portables.
793 For information on utilities to make use of this driver see the
794 Toshiba Linux utilities web site at:
795 <http://www.buzzard.org.uk/toshiba/>.
797 Say Y if you intend to run this kernel on a Toshiba portable.
801 tristate "Dell laptop support"
803 This adds a driver to safely access the System Management Mode
804 of the CPU on the Dell Inspiron 8000. The System Management Mode
805 is used to read cpu temperature and cooling fan status and to
806 control the fans on the I8K portables.
808 This driver has been tested only on the Inspiron 8000 but it may
809 also work with other Dell laptops. You can force loading on other
810 models by passing the parameter `force=1' to the module. Use at
813 For information on utilities to make use of this driver see the
814 I8K Linux utilities web site at:
815 <http://people.debian.org/~dz/i8k/>
817 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
820 config X86_REBOOTFIXUPS
821 bool "Enable X86 board specific fixups for reboot"
824 This enables chipset and/or board specific fixups to be done
825 in order to get reboot to work correctly. This is only needed on
826 some combinations of hardware and BIOS. The symptom, for which
827 this config is intended, is when reboot ends with a stalled/hung
830 Currently, the only fixup is for the Geode machines using
831 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
833 Say Y if you want to enable the fixup. Currently, it's safe to
834 enable this option even if you don't need it.
838 tristate "/dev/cpu/microcode - microcode support"
841 If you say Y here, you will be able to update the microcode on
842 certain Intel and AMD processors. The Intel support is for the
843 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
844 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
845 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
846 You will obviously need the actual microcode binary data itself
847 which is not shipped with the Linux kernel.
849 This option selects the general module only, you need to select
850 at least one vendor specific module as well.
852 To compile this driver as a module, choose M here: the
853 module will be called microcode.
855 config MICROCODE_INTEL
856 bool "Intel microcode patch loading support"
861 This options enables microcode patch loading support for Intel
864 For latest news and information on obtaining all the required
865 Intel ingredients for this driver, check:
866 <http://www.urbanmyth.org/microcode/>.
869 bool "AMD microcode patch loading support"
873 If you select this option, microcode patch loading support for AMD
874 processors will be enabled.
876 config MICROCODE_OLD_INTERFACE
881 tristate "/dev/cpu/*/msr - Model-specific register support"
883 This device gives privileged processes access to the x86
884 Model-Specific Registers (MSRs). It is a character device with
885 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
886 MSR accesses are directed to a specific CPU on multi-processor
890 tristate "/dev/cpu/*/cpuid - CPU information support"
892 This device gives processes access to the x86 CPUID instruction to
893 be executed on a specific processor. It is a character device
894 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
898 prompt "High Memory Support"
899 default HIGHMEM4G if !X86_NUMAQ
900 default HIGHMEM64G if X86_NUMAQ
905 depends on !X86_NUMAQ
907 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
908 However, the address space of 32-bit x86 processors is only 4
909 Gigabytes large. That means that, if you have a large amount of
910 physical memory, not all of it can be "permanently mapped" by the
911 kernel. The physical memory that's not permanently mapped is called
914 If you are compiling a kernel which will never run on a machine with
915 more than 1 Gigabyte total physical RAM, answer "off" here (default
916 choice and suitable for most users). This will result in a "3GB/1GB"
917 split: 3GB are mapped so that each process sees a 3GB virtual memory
918 space and the remaining part of the 4GB virtual memory space is used
919 by the kernel to permanently map as much physical memory as
922 If the machine has between 1 and 4 Gigabytes physical RAM, then
925 If more than 4 Gigabytes is used then answer "64GB" here. This
926 selection turns Intel PAE (Physical Address Extension) mode on.
927 PAE implements 3-level paging on IA32 processors. PAE is fully
928 supported by Linux, PAE mode is implemented on all recent Intel
929 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
930 then the kernel will not boot on CPUs that don't support PAE!
932 The actual amount of total physical memory will either be
933 auto detected or can be forced by using a kernel command line option
934 such as "mem=256M". (Try "man bootparam" or see the documentation of
935 your boot loader (lilo or loadlin) about how to pass options to the
936 kernel at boot time.)
938 If unsure, say "off".
942 depends on !X86_NUMAQ
944 Select this if you have a 32-bit processor and between 1 and 4
945 gigabytes of physical RAM.
949 depends on !M386 && !M486
952 Select this if you have a 32-bit processor and more than 4
953 gigabytes of physical RAM.
958 depends on EXPERIMENTAL
959 prompt "Memory split" if EMBEDDED
963 Select the desired split between kernel and user memory.
965 If the address range available to the kernel is less than the
966 physical memory installed, the remaining memory will be available
967 as "high memory". Accessing high memory is a little more costly
968 than low memory, as it needs to be mapped into the kernel first.
969 Note that increasing the kernel address space limits the range
970 available to user programs, making the address space there
971 tighter. Selecting anything other than the default 3G/1G split
972 will also likely make your kernel incompatible with binary-only
975 If you are not absolutely sure what you are doing, leave this
979 bool "3G/1G user/kernel split"
980 config VMSPLIT_3G_OPT
982 bool "3G/1G user/kernel split (for full 1G low memory)"
984 bool "2G/2G user/kernel split"
985 config VMSPLIT_2G_OPT
987 bool "2G/2G user/kernel split (for full 2G low memory)"
989 bool "1G/3G user/kernel split"
994 default 0xB0000000 if VMSPLIT_3G_OPT
995 default 0x80000000 if VMSPLIT_2G
996 default 0x78000000 if VMSPLIT_2G_OPT
997 default 0x40000000 if VMSPLIT_1G
1003 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1006 bool "PAE (Physical Address Extension) Support"
1007 depends on X86_32 && !HIGHMEM4G
1009 PAE is required for NX support, and furthermore enables
1010 larger swapspace support for non-overcommit purposes. It
1011 has the cost of more pagetable lookup overhead, and also
1012 consumes more pagetable space per process.
1014 config ARCH_PHYS_ADDR_T_64BIT
1015 def_bool X86_64 || X86_PAE
1017 config DIRECT_GBPAGES
1018 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1022 Allow the kernel linear mapping to use 1GB pages on CPUs that
1023 support it. This can improve the kernel's performance a tiny bit by
1024 reducing TLB pressure. If in doubt, say "Y".
1026 # Common NUMA Features
1028 bool "Numa Memory Allocation and Scheduler Support"
1030 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1031 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1033 Enable NUMA (Non Uniform Memory Access) support.
1035 The kernel will try to allocate memory used by a CPU on the
1036 local memory controller of the CPU and add some more
1037 NUMA awareness to the kernel.
1039 For 64-bit this is recommended if the system is Intel Core i7
1040 (or later), AMD Opteron, or EM64T NUMA.
1042 For 32-bit this is only needed on (rare) 32-bit-only platforms
1043 that support NUMA topologies, such as NUMAQ / Summit, or if you
1044 boot a 32-bit kernel on a 64-bit NUMA platform.
1046 Otherwise, you should say N.
1048 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1049 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1053 prompt "Old style AMD Opteron NUMA detection"
1054 depends on X86_64 && NUMA && PCI
1056 Enable K8 NUMA node topology detection. You should say Y here if
1057 you have a multi processor AMD K8 system. This uses an old
1058 method to read the NUMA configuration directly from the builtin
1059 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1060 instead, which also takes priority if both are compiled in.
1062 config X86_64_ACPI_NUMA
1064 prompt "ACPI NUMA detection"
1065 depends on X86_64 && NUMA && ACPI && PCI
1068 Enable ACPI SRAT based node topology detection.
1070 # Some NUMA nodes have memory ranges that span
1071 # other nodes. Even though a pfn is valid and
1072 # between a node's start and end pfns, it may not
1073 # reside on that node. See memmap_init_zone()
1075 config NODES_SPAN_OTHER_NODES
1077 depends on X86_64_ACPI_NUMA
1080 bool "NUMA emulation"
1081 depends on X86_64 && NUMA
1083 Enable NUMA emulation. A flat machine will be split
1084 into virtual nodes when booted with "numa=fake=N", where N is the
1085 number of nodes. This is only useful for debugging.
1088 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1090 default "9" if MAXSMP
1091 default "6" if X86_64
1092 default "4" if X86_NUMAQ
1094 depends on NEED_MULTIPLE_NODES
1096 Specify the maximum number of NUMA Nodes available on the target
1097 system. Increases memory reserved to accomodate various tables.
1099 config HAVE_ARCH_BOOTMEM_NODE
1101 depends on X86_32 && NUMA
1103 config ARCH_HAVE_MEMORY_PRESENT
1105 depends on X86_32 && DISCONTIGMEM
1107 config NEED_NODE_MEMMAP_SIZE
1109 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1111 config HAVE_ARCH_ALLOC_REMAP
1113 depends on X86_32 && NUMA
1115 config ARCH_FLATMEM_ENABLE
1117 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1119 config ARCH_DISCONTIGMEM_ENABLE
1121 depends on NUMA && X86_32
1123 config ARCH_DISCONTIGMEM_DEFAULT
1125 depends on NUMA && X86_32
1127 config ARCH_SPARSEMEM_DEFAULT
1131 config ARCH_SPARSEMEM_ENABLE
1133 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1134 select SPARSEMEM_STATIC if X86_32
1135 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1137 config ARCH_SELECT_MEMORY_MODEL
1139 depends on ARCH_SPARSEMEM_ENABLE
1141 config ARCH_MEMORY_PROBE
1143 depends on MEMORY_HOTPLUG
1148 bool "Allocate 3rd-level pagetables from highmem"
1149 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1151 The VM uses one page table entry for each page of physical memory.
1152 For systems with a lot of RAM, this can be wasteful of precious
1153 low memory. Setting this option will put user-space page table
1154 entries in high memory.
1156 config X86_CHECK_BIOS_CORRUPTION
1157 bool "Check for low memory corruption"
1159 Periodically check for memory corruption in low memory, which
1160 is suspected to be caused by BIOS. Even when enabled in the
1161 configuration, it is disabled at runtime. Enable it by
1162 setting "memory_corruption_check=1" on the kernel command
1163 line. By default it scans the low 64k of memory every 60
1164 seconds; see the memory_corruption_check_size and
1165 memory_corruption_check_period parameters in
1166 Documentation/kernel-parameters.txt to adjust this.
1168 When enabled with the default parameters, this option has
1169 almost no overhead, as it reserves a relatively small amount
1170 of memory and scans it infrequently. It both detects corruption
1171 and prevents it from affecting the running system.
1173 It is, however, intended as a diagnostic tool; if repeatable
1174 BIOS-originated corruption always affects the same memory,
1175 you can use memmap= to prevent the kernel from using that
1178 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1179 bool "Set the default setting of memory_corruption_check"
1180 depends on X86_CHECK_BIOS_CORRUPTION
1183 Set whether the default state of memory_corruption_check is
1186 config X86_RESERVE_LOW_64K
1187 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1190 Reserve the first 64K of physical RAM on BIOSes that are known
1191 to potentially corrupt that memory range. A numbers of BIOSes are
1192 known to utilize this area during suspend/resume, so it must not
1193 be used by the kernel.
1195 Set this to N if you are absolutely sure that you trust the BIOS
1196 to get all its memory reservations and usages right.
1198 If you have doubts about the BIOS (e.g. suspend/resume does not
1199 work or there's kernel crashes after certain hardware hotplug
1200 events) and it's not AMI or Phoenix, then you might want to enable
1201 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1202 corruption patterns.
1206 config MATH_EMULATION
1208 prompt "Math emulation" if X86_32
1210 Linux can emulate a math coprocessor (used for floating point
1211 operations) if you don't have one. 486DX and Pentium processors have
1212 a math coprocessor built in, 486SX and 386 do not, unless you added
1213 a 487DX or 387, respectively. (The messages during boot time can
1214 give you some hints here ["man dmesg"].) Everyone needs either a
1215 coprocessor or this emulation.
1217 If you don't have a math coprocessor, you need to say Y here; if you
1218 say Y here even though you have a coprocessor, the coprocessor will
1219 be used nevertheless. (This behavior can be changed with the kernel
1220 command line option "no387", which comes handy if your coprocessor
1221 is broken. Try "man bootparam" or see the documentation of your boot
1222 loader (lilo or loadlin) about how to pass options to the kernel at
1223 boot time.) This means that it is a good idea to say Y here if you
1224 intend to use this kernel on different machines.
1226 More information about the internals of the Linux math coprocessor
1227 emulation can be found in <file:arch/x86/math-emu/README>.
1229 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1230 kernel, it won't hurt.
1233 bool "MTRR (Memory Type Range Register) support"
1235 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1236 the Memory Type Range Registers (MTRRs) may be used to control
1237 processor access to memory ranges. This is most useful if you have
1238 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1239 allows bus write transfers to be combined into a larger transfer
1240 before bursting over the PCI/AGP bus. This can increase performance
1241 of image write operations 2.5 times or more. Saying Y here creates a
1242 /proc/mtrr file which may be used to manipulate your processor's
1243 MTRRs. Typically the X server should use this.
1245 This code has a reasonably generic interface so that similar
1246 control registers on other processors can be easily supported
1249 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1250 Registers (ARRs) which provide a similar functionality to MTRRs. For
1251 these, the ARRs are used to emulate the MTRRs.
1252 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1253 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1254 write-combining. All of these processors are supported by this code
1255 and it makes sense to say Y here if you have one of them.
1257 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1258 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1259 can lead to all sorts of problems, so it's good to say Y here.
1261 You can safely say Y even if your machine doesn't have MTRRs, you'll
1262 just add about 9 KB to your kernel.
1264 See <file:Documentation/x86/mtrr.txt> for more information.
1266 config MTRR_SANITIZER
1268 prompt "MTRR cleanup support"
1271 Convert MTRR layout from continuous to discrete, so X drivers can
1272 add writeback entries.
1274 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1275 The largest mtrr entry size for a continous block can be set with
1280 config MTRR_SANITIZER_ENABLE_DEFAULT
1281 int "MTRR cleanup enable value (0-1)"
1284 depends on MTRR_SANITIZER
1286 Enable mtrr cleanup default value
1288 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1289 int "MTRR cleanup spare reg num (0-7)"
1292 depends on MTRR_SANITIZER
1294 mtrr cleanup spare entries default, it can be changed via
1295 mtrr_spare_reg_nr=N on the kernel command line.
1299 prompt "x86 PAT support"
1302 Use PAT attributes to setup page level cache control.
1304 PATs are the modern equivalents of MTRRs and are much more
1305 flexible than MTRRs.
1307 Say N here if you see bootup problems (boot crash, boot hang,
1308 spontaneous reboots) or a non-working video driver.
1313 bool "EFI runtime service support"
1316 This enables the kernel to use EFI runtime services that are
1317 available (such as the EFI variable services).
1319 This option is only useful on systems that have EFI firmware.
1320 In addition, you should use the latest ELILO loader available
1321 at <http://elilo.sourceforge.net> in order to take advantage
1322 of EFI runtime services. However, even with this option, the
1323 resultant kernel should continue to boot on existing non-EFI
1328 prompt "Enable seccomp to safely compute untrusted bytecode"
1330 This kernel feature is useful for number crunching applications
1331 that may need to compute untrusted bytecode during their
1332 execution. By using pipes or other transports made available to
1333 the process as file descriptors supporting the read/write
1334 syscalls, it's possible to isolate those applications in
1335 their own address space using seccomp. Once seccomp is
1336 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1337 and the task is only allowed to execute a few safe syscalls
1338 defined by each seccomp mode.
1340 If unsure, say Y. Only embedded should say N here.
1342 config CC_STACKPROTECTOR_ALL
1345 config CC_STACKPROTECTOR
1346 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1347 select CC_STACKPROTECTOR_ALL
1349 This option turns on the -fstack-protector GCC feature. This
1350 feature puts, at the beginning of functions, a canary value on
1351 the stack just before the return address, and validates
1352 the value just before actually returning. Stack based buffer
1353 overflows (that need to overwrite this return address) now also
1354 overwrite the canary, which gets detected and the attack is then
1355 neutralized via a kernel panic.
1357 This feature requires gcc version 4.2 or above, or a distribution
1358 gcc with the feature backported. Older versions are automatically
1359 detected and for those versions, this configuration option is
1360 ignored. (and a warning is printed during bootup)
1362 source kernel/Kconfig.hz
1365 bool "kexec system call"
1367 kexec is a system call that implements the ability to shutdown your
1368 current kernel, and to start another kernel. It is like a reboot
1369 but it is independent of the system firmware. And like a reboot
1370 you can start any kernel with it, not just Linux.
1372 The name comes from the similarity to the exec system call.
1374 It is an ongoing process to be certain the hardware in a machine
1375 is properly shutdown, so do not be surprised if this code does not
1376 initially work for you. It may help to enable device hotplugging
1377 support. As of this writing the exact hardware interface is
1378 strongly in flux, so no good recommendation can be made.
1381 bool "kernel crash dumps"
1382 depends on X86_64 || (X86_32 && HIGHMEM)
1384 Generate crash dump after being started by kexec.
1385 This should be normally only set in special crash dump kernels
1386 which are loaded in the main kernel with kexec-tools into
1387 a specially reserved region and then later executed after
1388 a crash by kdump/kexec. The crash dump kernel must be compiled
1389 to a memory address not used by the main kernel or BIOS using
1390 PHYSICAL_START, or it must be built as a relocatable image
1391 (CONFIG_RELOCATABLE=y).
1392 For more details see Documentation/kdump/kdump.txt
1395 bool "kexec jump (EXPERIMENTAL)"
1396 depends on EXPERIMENTAL
1397 depends on KEXEC && HIBERNATION && X86_32
1399 Jump between original kernel and kexeced kernel and invoke
1400 code in physical address mode via KEXEC
1402 config PHYSICAL_START
1403 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1404 default "0x1000000" if X86_NUMAQ
1405 default "0x200000" if X86_64
1408 This gives the physical address where the kernel is loaded.
1410 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1411 bzImage will decompress itself to above physical address and
1412 run from there. Otherwise, bzImage will run from the address where
1413 it has been loaded by the boot loader and will ignore above physical
1416 In normal kdump cases one does not have to set/change this option
1417 as now bzImage can be compiled as a completely relocatable image
1418 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1419 address. This option is mainly useful for the folks who don't want
1420 to use a bzImage for capturing the crash dump and want to use a
1421 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1422 to be specifically compiled to run from a specific memory area
1423 (normally a reserved region) and this option comes handy.
1425 So if you are using bzImage for capturing the crash dump, leave
1426 the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1427 Otherwise if you plan to use vmlinux for capturing the crash dump
1428 change this value to start of the reserved region (Typically 16MB
1429 0x1000000). In other words, it can be set based on the "X" value as
1430 specified in the "crashkernel=YM@XM" command line boot parameter
1431 passed to the panic-ed kernel. Typically this parameter is set as
1432 crashkernel=64M@16M. Please take a look at
1433 Documentation/kdump/kdump.txt for more details about crash dumps.
1435 Usage of bzImage for capturing the crash dump is recommended as
1436 one does not have to build two kernels. Same kernel can be used
1437 as production kernel and capture kernel. Above option should have
1438 gone away after relocatable bzImage support is introduced. But it
1439 is present because there are users out there who continue to use
1440 vmlinux for dump capture. This option should go away down the
1443 Don't change this unless you know what you are doing.
1446 bool "Build a relocatable kernel (EXPERIMENTAL)"
1447 depends on EXPERIMENTAL
1449 This builds a kernel image that retains relocation information
1450 so it can be loaded someplace besides the default 1MB.
1451 The relocations tend to make the kernel binary about 10% larger,
1452 but are discarded at runtime.
1454 One use is for the kexec on panic case where the recovery kernel
1455 must live at a different physical address than the primary
1458 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1459 it has been loaded at and the compile time physical address
1460 (CONFIG_PHYSICAL_START) is ignored.
1462 config PHYSICAL_ALIGN
1464 prompt "Alignment value to which kernel should be aligned" if X86_32
1465 default "0x100000" if X86_32
1466 default "0x200000" if X86_64
1467 range 0x2000 0x400000
1469 This value puts the alignment restrictions on physical address
1470 where kernel is loaded and run from. Kernel is compiled for an
1471 address which meets above alignment restriction.
1473 If bootloader loads the kernel at a non-aligned address and
1474 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1475 address aligned to above value and run from there.
1477 If bootloader loads the kernel at a non-aligned address and
1478 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1479 load address and decompress itself to the address it has been
1480 compiled for and run from there. The address for which kernel is
1481 compiled already meets above alignment restrictions. Hence the
1482 end result is that kernel runs from a physical address meeting
1483 above alignment restrictions.
1485 Don't change this unless you know what you are doing.
1488 bool "Support for hot-pluggable CPUs"
1489 depends on SMP && HOTPLUG
1491 Say Y here to allow turning CPUs off and on. CPUs can be
1492 controlled through /sys/devices/system/cpu.
1493 ( Note: power management support will enable this option
1494 automatically on SMP systems. )
1495 Say N if you want to disable CPU hotplug.
1499 prompt "Compat VDSO support"
1500 depends on X86_32 || IA32_EMULATION
1502 Map the 32-bit VDSO to the predictable old-style address too.
1504 Say N here if you are running a sufficiently recent glibc
1505 version (2.3.3 or later), to remove the high-mapped
1506 VDSO mapping and to exclusively use the randomized VDSO.
1511 bool "Built-in kernel command line"
1514 Allow for specifying boot arguments to the kernel at
1515 build time. On some systems (e.g. embedded ones), it is
1516 necessary or convenient to provide some or all of the
1517 kernel boot arguments with the kernel itself (that is,
1518 to not rely on the boot loader to provide them.)
1520 To compile command line arguments into the kernel,
1521 set this option to 'Y', then fill in the
1522 the boot arguments in CONFIG_CMDLINE.
1524 Systems with fully functional boot loaders (i.e. non-embedded)
1525 should leave this option set to 'N'.
1528 string "Built-in kernel command string"
1529 depends on CMDLINE_BOOL
1532 Enter arguments here that should be compiled into the kernel
1533 image and used at boot time. If the boot loader provides a
1534 command line at boot time, it is appended to this string to
1535 form the full kernel command line, when the system boots.
1537 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1538 change this behavior.
1540 In most cases, the command line (whether built-in or provided
1541 by the boot loader) should specify the device for the root
1544 config CMDLINE_OVERRIDE
1545 bool "Built-in command line overrides boot loader arguments"
1547 depends on CMDLINE_BOOL
1549 Set this option to 'Y' to have the kernel ignore the boot loader
1550 command line, and use ONLY the built-in command line.
1552 This is used to work around broken boot loaders. This should
1553 be set to 'N' under normal conditions.
1557 config ARCH_ENABLE_MEMORY_HOTPLUG
1559 depends on X86_64 || (X86_32 && HIGHMEM)
1561 config ARCH_ENABLE_MEMORY_HOTREMOVE
1563 depends on MEMORY_HOTPLUG
1565 config HAVE_ARCH_EARLY_PFN_TO_NID
1569 menu "Power management and ACPI options"
1571 config ARCH_HIBERNATION_HEADER
1573 depends on X86_64 && HIBERNATION
1575 source "kernel/power/Kconfig"
1577 source "drivers/acpi/Kconfig"
1582 depends on APM || APM_MODULE
1585 tristate "APM (Advanced Power Management) BIOS support"
1586 depends on X86_32 && PM_SLEEP
1588 APM is a BIOS specification for saving power using several different
1589 techniques. This is mostly useful for battery powered laptops with
1590 APM compliant BIOSes. If you say Y here, the system time will be
1591 reset after a RESUME operation, the /proc/apm device will provide
1592 battery status information, and user-space programs will receive
1593 notification of APM "events" (e.g. battery status change).
1595 If you select "Y" here, you can disable actual use of the APM
1596 BIOS by passing the "apm=off" option to the kernel at boot time.
1598 Note that the APM support is almost completely disabled for
1599 machines with more than one CPU.
1601 In order to use APM, you will need supporting software. For location
1602 and more information, read <file:Documentation/power/pm.txt> and the
1603 Battery Powered Linux mini-HOWTO, available from
1604 <http://www.tldp.org/docs.html#howto>.
1606 This driver does not spin down disk drives (see the hdparm(8)
1607 manpage ("man 8 hdparm") for that), and it doesn't turn off
1608 VESA-compliant "green" monitors.
1610 This driver does not support the TI 4000M TravelMate and the ACER
1611 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1612 desktop machines also don't have compliant BIOSes, and this driver
1613 may cause those machines to panic during the boot phase.
1615 Generally, if you don't have a battery in your machine, there isn't
1616 much point in using this driver and you should say N. If you get
1617 random kernel OOPSes or reboots that don't seem to be related to
1618 anything, try disabling/enabling this option (or disabling/enabling
1621 Some other things you should try when experiencing seemingly random,
1624 1) make sure that you have enough swap space and that it is
1626 2) pass the "no-hlt" option to the kernel
1627 3) switch on floating point emulation in the kernel and pass
1628 the "no387" option to the kernel
1629 4) pass the "floppy=nodma" option to the kernel
1630 5) pass the "mem=4M" option to the kernel (thereby disabling
1631 all but the first 4 MB of RAM)
1632 6) make sure that the CPU is not over clocked.
1633 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1634 8) disable the cache from your BIOS settings
1635 9) install a fan for the video card or exchange video RAM
1636 10) install a better fan for the CPU
1637 11) exchange RAM chips
1638 12) exchange the motherboard.
1640 To compile this driver as a module, choose M here: the
1641 module will be called apm.
1645 config APM_IGNORE_USER_SUSPEND
1646 bool "Ignore USER SUSPEND"
1648 This option will ignore USER SUSPEND requests. On machines with a
1649 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1650 series notebooks, it is necessary to say Y because of a BIOS bug.
1652 config APM_DO_ENABLE
1653 bool "Enable PM at boot time"
1655 Enable APM features at boot time. From page 36 of the APM BIOS
1656 specification: "When disabled, the APM BIOS does not automatically
1657 power manage devices, enter the Standby State, enter the Suspend
1658 State, or take power saving steps in response to CPU Idle calls."
1659 This driver will make CPU Idle calls when Linux is idle (unless this
1660 feature is turned off -- see "Do CPU IDLE calls", below). This
1661 should always save battery power, but more complicated APM features
1662 will be dependent on your BIOS implementation. You may need to turn
1663 this option off if your computer hangs at boot time when using APM
1664 support, or if it beeps continuously instead of suspending. Turn
1665 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1666 T400CDT. This is off by default since most machines do fine without
1670 bool "Make CPU Idle calls when idle"
1672 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1673 On some machines, this can activate improved power savings, such as
1674 a slowed CPU clock rate, when the machine is idle. These idle calls
1675 are made after the idle loop has run for some length of time (e.g.,
1676 333 mS). On some machines, this will cause a hang at boot time or
1677 whenever the CPU becomes idle. (On machines with more than one CPU,
1678 this option does nothing.)
1680 config APM_DISPLAY_BLANK
1681 bool "Enable console blanking using APM"
1683 Enable console blanking using the APM. Some laptops can use this to
1684 turn off the LCD backlight when the screen blanker of the Linux
1685 virtual console blanks the screen. Note that this is only used by
1686 the virtual console screen blanker, and won't turn off the backlight
1687 when using the X Window system. This also doesn't have anything to
1688 do with your VESA-compliant power-saving monitor. Further, this
1689 option doesn't work for all laptops -- it might not turn off your
1690 backlight at all, or it might print a lot of errors to the console,
1691 especially if you are using gpm.
1693 config APM_ALLOW_INTS
1694 bool "Allow interrupts during APM BIOS calls"
1696 Normally we disable external interrupts while we are making calls to
1697 the APM BIOS as a measure to lessen the effects of a badly behaving
1698 BIOS implementation. The BIOS should reenable interrupts if it
1699 needs to. Unfortunately, some BIOSes do not -- especially those in
1700 many of the newer IBM Thinkpads. If you experience hangs when you
1701 suspend, try setting this to Y. Otherwise, say N.
1705 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1707 source "drivers/cpuidle/Kconfig"
1709 source "drivers/idle/Kconfig"
1714 menu "Bus options (PCI etc.)"
1719 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1721 Find out whether you have a PCI motherboard. PCI is the name of a
1722 bus system, i.e. the way the CPU talks to the other stuff inside
1723 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1724 VESA. If you have PCI, say Y, otherwise N.
1727 prompt "PCI access mode"
1728 depends on X86_32 && PCI
1731 On PCI systems, the BIOS can be used to detect the PCI devices and
1732 determine their configuration. However, some old PCI motherboards
1733 have BIOS bugs and may crash if this is done. Also, some embedded
1734 PCI-based systems don't have any BIOS at all. Linux can also try to
1735 detect the PCI hardware directly without using the BIOS.
1737 With this option, you can specify how Linux should detect the
1738 PCI devices. If you choose "BIOS", the BIOS will be used,
1739 if you choose "Direct", the BIOS won't be used, and if you
1740 choose "MMConfig", then PCI Express MMCONFIG will be used.
1741 If you choose "Any", the kernel will try MMCONFIG, then the
1742 direct access method and falls back to the BIOS if that doesn't
1743 work. If unsure, go with the default, which is "Any".
1748 config PCI_GOMMCONFIG
1765 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1767 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1770 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1774 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1778 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1785 bool "Support mmconfig PCI config space access"
1786 depends on X86_64 && PCI && ACPI
1789 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1790 depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1792 DMA remapping (DMAR) devices support enables independent address
1793 translations for Direct Memory Access (DMA) from devices.
1794 These DMA remapping devices are reported via ACPI tables
1795 and include PCI device scope covered by these DMA
1798 config DMAR_DEFAULT_ON
1800 prompt "Enable DMA Remapping Devices by default"
1803 Selecting this option will enable a DMAR device at boot time if
1804 one is found. If this option is not selected, DMAR support can
1805 be enabled by passing intel_iommu=on to the kernel. It is
1806 recommended you say N here while the DMAR code remains
1811 prompt "Support for Graphics workaround"
1814 Current Graphics drivers tend to use physical address
1815 for DMA and avoid using DMA APIs. Setting this config
1816 option permits the IOMMU driver to set a unity map for
1817 all the OS-visible memory. Hence the driver can continue
1818 to use physical addresses for DMA.
1820 config DMAR_FLOPPY_WA
1824 Floppy disk drivers are know to bypass DMA API calls
1825 thereby failing to work when IOMMU is enabled. This
1826 workaround will setup a 1:1 mapping for the first
1827 16M to make floppy (an ISA device) work.
1830 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1831 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1833 Supports Interrupt remapping for IO-APIC and MSI devices.
1834 To use x2apic mode in the CPU's which support x2APIC enhancements or
1835 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1837 source "drivers/pci/pcie/Kconfig"
1839 source "drivers/pci/Kconfig"
1841 # x86_64 have no ISA slots, but do have ISA-style DMA.
1850 Find out whether you have ISA slots on your motherboard. ISA is the
1851 name of a bus system, i.e. the way the CPU talks to the other stuff
1852 inside your box. Other bus systems are PCI, EISA, MicroChannel
1853 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1854 newer boards don't support it. If you have ISA, say Y, otherwise N.
1860 The Extended Industry Standard Architecture (EISA) bus was
1861 developed as an open alternative to the IBM MicroChannel bus.
1863 The EISA bus provided some of the features of the IBM MicroChannel
1864 bus while maintaining backward compatibility with cards made for
1865 the older ISA bus. The EISA bus saw limited use between 1988 and
1866 1995 when it was made obsolete by the PCI bus.
1868 Say Y here if you are building a kernel for an EISA-based machine.
1872 source "drivers/eisa/Kconfig"
1877 MicroChannel Architecture is found in some IBM PS/2 machines and
1878 laptops. It is a bus system similar to PCI or ISA. See
1879 <file:Documentation/mca.txt> (and especially the web page given
1880 there) before attempting to build an MCA bus kernel.
1882 source "drivers/mca/Kconfig"
1885 tristate "NatSemi SCx200 support"
1887 This provides basic support for National Semiconductor's
1888 (now AMD's) Geode processors. The driver probes for the
1889 PCI-IDs of several on-chip devices, so its a good dependency
1890 for other scx200_* drivers.
1892 If compiled as a module, the driver is named scx200.
1894 config SCx200HR_TIMER
1895 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1896 depends on SCx200 && GENERIC_TIME
1899 This driver provides a clocksource built upon the on-chip
1900 27MHz high-resolution timer. Its also a workaround for
1901 NSC Geode SC-1100's buggy TSC, which loses time when the
1902 processor goes idle (as is done by the scheduler). The
1903 other workaround is idle=poll boot option.
1905 config GEODE_MFGPT_TIMER
1907 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1908 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1910 This driver provides a clock event source based on the MFGPT
1911 timer(s) in the CS5535 and CS5536 companion chip for the geode.
1912 MFGPTs have a better resolution and max interval than the
1913 generic PIT, and are suitable for use as high-res timers.
1916 bool "One Laptop Per Child support"
1919 Add support for detecting the unique features of the OLPC
1926 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1928 source "drivers/pcmcia/Kconfig"
1930 source "drivers/pci/hotplug/Kconfig"
1935 menu "Executable file formats / Emulations"
1937 source "fs/Kconfig.binfmt"
1939 config IA32_EMULATION
1940 bool "IA32 Emulation"
1942 select COMPAT_BINFMT_ELF
1944 Include code to run 32-bit programs under a 64-bit kernel. You should
1945 likely turn this on, unless you're 100% sure that you don't have any
1946 32-bit programs left.
1949 tristate "IA32 a.out support"
1950 depends on IA32_EMULATION
1952 Support old a.out binaries in the 32bit emulation.
1956 depends on IA32_EMULATION
1958 config COMPAT_FOR_U64_ALIGNMENT
1962 config SYSVIPC_COMPAT
1964 depends on COMPAT && SYSVIPC
1969 config HAVE_ATOMIC_IOMAP
1973 source "net/Kconfig"
1975 source "drivers/Kconfig"
1977 source "drivers/firmware/Kconfig"
1981 source "arch/x86/Kconfig.debug"
1983 source "security/Kconfig"
1985 source "crypto/Kconfig"
1987 source "arch/x86/kvm/Kconfig"
1989 source "lib/Kconfig"