3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select HAVE_AOUT if X86_32
21 select HAVE_UNSTABLE_SCHED_CLOCK
24 select HAVE_PERF_EVENTS
26 select HAVE_IOREMAP_PROT
29 select ARCH_WANT_OPTIONAL_GPIOLIB
30 select ARCH_WANT_FRAME_POINTERS
32 select HAVE_KRETPROBES
34 select HAVE_FTRACE_MCOUNT_RECORD
35 select HAVE_C_RECORDMCOUNT
36 select HAVE_DYNAMIC_FTRACE
37 select HAVE_FUNCTION_TRACER
38 select HAVE_FUNCTION_GRAPH_TRACER
39 select HAVE_FUNCTION_GRAPH_FP_TEST
40 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
41 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
42 select HAVE_SYSCALL_TRACEPOINTS
45 select HAVE_ARCH_TRACEHOOK
46 select HAVE_GENERIC_DMA_COHERENT if X86_32
47 select HAVE_EFFICIENT_UNALIGNED_ACCESS
48 select USER_STACKTRACE_SUPPORT
49 select HAVE_REGS_AND_STACK_ACCESS_API
50 select HAVE_DMA_API_DEBUG
51 select HAVE_KERNEL_GZIP
52 select HAVE_KERNEL_BZIP2
53 select HAVE_KERNEL_LZMA
55 select HAVE_KERNEL_LZO
56 select HAVE_HW_BREAKPOINT
57 select HAVE_MIXED_BREAKPOINTS_REGS
59 select HAVE_PERF_EVENTS_NMI
61 select HAVE_ARCH_KMEMCHECK
62 select HAVE_USER_RETURN_NOTIFIER
63 select HAVE_ARCH_JUMP_LABEL
64 select HAVE_TEXT_POKE_SMP
65 select HAVE_GENERIC_HARDIRQS
66 select HAVE_SPARSE_IRQ
67 select GENERIC_FIND_FIRST_BIT
68 select GENERIC_FIND_NEXT_BIT
69 select GENERIC_IRQ_PROBE
70 select GENERIC_PENDING_IRQ if SMP
71 select GENERIC_IRQ_SHOW
72 select IRQ_FORCED_THREADING
73 select USE_GENERIC_SMP_HELPERS if SMP
74 select ARCH_NO_SYSDEV_OPS
76 config INSTRUCTION_DECODER
77 def_bool (KPROBES || PERF_EVENTS)
81 default "elf32-i386" if X86_32
82 default "elf64-x86-64" if X86_64
86 default "arch/x86/configs/i386_defconfig" if X86_32
87 default "arch/x86/configs/x86_64_defconfig" if X86_64
89 config GENERIC_CMOS_UPDATE
92 config CLOCKSOURCE_WATCHDOG
95 config GENERIC_CLOCKEVENTS
98 config GENERIC_CLOCKEVENTS_BROADCAST
100 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
102 config LOCKDEP_SUPPORT
105 config STACKTRACE_SUPPORT
108 config HAVE_LATENCYTOP_SUPPORT
120 config NEED_DMA_MAP_STATE
121 def_bool (X86_64 || DMAR || DMA_API_DEBUG)
123 config NEED_SG_DMA_LENGTH
126 config GENERIC_ISA_DMA
135 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
137 config GENERIC_BUG_RELATIVE_POINTERS
140 config GENERIC_HWEIGHT
146 config ARCH_MAY_HAVE_PC_FDC
149 config RWSEM_GENERIC_SPINLOCK
152 config RWSEM_XCHGADD_ALGORITHM
155 config ARCH_HAS_CPU_IDLE_WAIT
158 config GENERIC_CALIBRATE_DELAY
161 config GENERIC_TIME_VSYSCALL
165 config ARCH_HAS_CPU_RELAX
168 config ARCH_HAS_DEFAULT_IDLE
171 config ARCH_HAS_CACHE_LINE_SIZE
174 config HAVE_SETUP_PER_CPU_AREA
177 config NEED_PER_CPU_EMBED_FIRST_CHUNK
180 config NEED_PER_CPU_PAGE_FIRST_CHUNK
183 config HAVE_CPUMASK_OF_CPU_MAP
186 config ARCH_HIBERNATION_POSSIBLE
189 config ARCH_SUSPEND_POSSIBLE
196 config ARCH_POPULATES_NODE_MAP
203 config ARCH_SUPPORTS_OPTIMIZED_INLINING
206 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
209 config HAVE_INTEL_TXT
211 depends on EXPERIMENTAL && DMAR && ACPI
215 depends on X86_32 && SMP
219 depends on X86_64 && SMP
225 config X86_32_LAZY_GS
227 depends on X86_32 && !CC_STACKPROTECTOR
229 config ARCH_HWEIGHT_CFLAGS
231 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
232 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
237 config ARCH_CPU_PROBE_RELEASE
239 depends on HOTPLUG_CPU
241 source "init/Kconfig"
242 source "kernel/Kconfig.freezer"
244 menu "Processor type and features"
246 source "kernel/time/Kconfig"
249 bool "Symmetric multi-processing support"
251 This enables support for systems with more than one CPU. If you have
252 a system with only one CPU, like most personal computers, say N. If
253 you have a system with more than one CPU, say Y.
255 If you say N here, the kernel will run on single and multiprocessor
256 machines, but will use only one CPU of a multiprocessor machine. If
257 you say Y here, the kernel will run on many, but not all,
258 singleprocessor machines. On a singleprocessor machine, the kernel
259 will run faster if you say N here.
261 Note that if you say Y here and choose architecture "586" or
262 "Pentium" under "Processor family", the kernel will not work on 486
263 architectures. Similarly, multiprocessor kernels for the "PPro"
264 architecture may not work on all Pentium based boards.
266 People using multiprocessor machines who say Y here should also say
267 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
268 Management" code will be disabled if you say Y here.
270 See also <file:Documentation/i386/IO-APIC.txt>,
271 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
272 <http://www.tldp.org/docs.html#howto>.
274 If you don't know what to do here, say N.
277 bool "Support x2apic"
278 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
280 This enables x2apic support on CPUs that have this feature.
282 This allows 32-bit apic IDs (so it can support very large systems),
283 and accesses the local apic via MSRs not via mmio.
285 If you don't know what to do here, say N.
288 bool "Enable MPS table" if ACPI
290 depends on X86_LOCAL_APIC
292 For old smp systems that do not have proper acpi support. Newer systems
293 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
296 bool "Support for big SMP systems with more than 8 CPUs"
297 depends on X86_32 && SMP
299 This option is needed for the systems that have more than 8 CPUs
302 config X86_EXTENDED_PLATFORM
303 bool "Support for extended (non-PC) x86 platforms"
306 If you disable this option then the kernel will only support
307 standard PC platforms. (which covers the vast majority of
310 If you enable this option then you'll be able to select support
311 for the following (non-PC) 32 bit x86 platforms:
315 SGI 320/540 (Visual Workstation)
316 Summit/EXA (IBM x440)
317 Unisys ES7000 IA32 series
318 Moorestown MID devices
320 If you have one of these systems, or if you want to build a
321 generic distribution kernel, say Y here - otherwise say N.
325 config X86_EXTENDED_PLATFORM
326 bool "Support for extended (non-PC) x86 platforms"
329 If you disable this option then the kernel will only support
330 standard PC platforms. (which covers the vast majority of
333 If you enable this option then you'll be able to select support
334 for the following (non-PC) 64 bit x86 platforms:
338 If you have one of these systems, or if you want to build a
339 generic distribution kernel, say Y here - otherwise say N.
341 # This is an alphabetically sorted list of 64 bit extended platforms
342 # Please maintain the alphabetic order if and when there are additions
346 select PARAVIRT_GUEST
348 depends on X86_64 && PCI
349 depends on X86_EXTENDED_PLATFORM
351 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
352 supposed to run on these EM64T-based machines. Only choose this option
353 if you have one of these machines.
356 bool "SGI Ultraviolet"
358 depends on X86_EXTENDED_PLATFORM
360 depends on X86_X2APIC
362 This option is needed in order to support SGI Ultraviolet systems.
363 If you don't have one of these, you should say N here.
365 # Following is an alphabetically sorted list of 32 bit extended platforms
366 # Please maintain the alphabetic order if and when there are additions
369 bool "CE4100 TV platform"
371 depends on PCI_GODIRECT
373 depends on X86_EXTENDED_PLATFORM
374 select X86_REBOOTFIXUPS
376 select OF_EARLY_FLATTREE
378 Select for the Intel CE media processor (CE4100) SOC.
379 This option compiles in support for the CE4100 SOC for settop
380 boxes and media devices.
383 bool "Moorestown MID platform"
387 depends on X86_EXTENDED_PLATFORM
388 depends on X86_IO_APIC
393 select X86_PLATFORM_DEVICES
395 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
396 Internet Device(MID) platform. Moorestown consists of two chips:
397 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
398 Unlike standard x86 PCs, Moorestown does not have many legacy devices
399 nor standard legacy replacement devices/features. e.g. Moorestown does
400 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
403 bool "RDC R-321x SoC"
405 depends on X86_EXTENDED_PLATFORM
407 select X86_REBOOTFIXUPS
409 This option is needed for RDC R-321x system-on-chip, also known
411 If you don't have one of these chips, you should say N here.
413 config X86_32_NON_STANDARD
414 bool "Support non-standard 32-bit SMP architectures"
415 depends on X86_32 && SMP
416 depends on X86_EXTENDED_PLATFORM
418 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
419 subarchitectures. It is intended for a generic binary kernel.
420 if you select them all, kernel will probe it one by one. and will
423 # Alphabetically sorted list of Non standard 32 bit platforms
426 bool "NUMAQ (IBM/Sequent)"
427 depends on X86_32_NON_STANDARD
432 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
433 NUMA multiquad box. This changes the way that processors are
434 bootstrapped, and uses Clustered Logical APIC addressing mode instead
435 of Flat Logical. You will need a new lynxer.elf file to flash your
436 firmware with - send email to <Martin.Bligh@us.ibm.com>.
438 config X86_SUPPORTS_MEMORY_FAILURE
440 # MCE code calls memory_failure():
442 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
443 depends on !X86_NUMAQ
444 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
445 depends on X86_64 || !SPARSEMEM
446 select ARCH_SUPPORTS_MEMORY_FAILURE
449 bool "SGI 320/540 (Visual Workstation)"
450 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
451 depends on X86_32_NON_STANDARD
453 The SGI Visual Workstation series is an IA32-based workstation
454 based on SGI systems chips with some legacy PC hardware attached.
456 Say Y here to create a kernel to run on the SGI 320 or 540.
458 A kernel compiled for the Visual Workstation will run on general
459 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
462 bool "Summit/EXA (IBM x440)"
463 depends on X86_32_NON_STANDARD
465 This option is needed for IBM systems that use the Summit/EXA chipset.
466 In particular, it is needed for the x440.
469 bool "Unisys ES7000 IA32 series"
470 depends on X86_32_NON_STANDARD && X86_BIGSMP
472 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
473 supposed to run on an IA32-based Unisys ES7000 system.
476 tristate "Eurobraille/Iris poweroff module"
479 The Iris machines from EuroBraille do not have APM or ACPI support
480 to shut themselves down properly. A special I/O sequence is
481 needed to do so, which is what this module does at
484 This is only for Iris machines from EuroBraille.
488 config SCHED_OMIT_FRAME_POINTER
490 prompt "Single-depth WCHAN output"
493 Calculate simpler /proc/<PID>/wchan values. If this option
494 is disabled then wchan values will recurse back to the
495 caller function. This provides more accurate wchan values,
496 at the expense of slightly more scheduling overhead.
498 If in doubt, say "Y".
500 menuconfig PARAVIRT_GUEST
501 bool "Paravirtualized guest support"
503 Say Y here to get to see options related to running Linux under
504 various hypervisors. This option alone does not add any kernel code.
506 If you say N, all options in this submenu will be skipped and disabled.
510 source "arch/x86/xen/Kconfig"
513 bool "KVM paravirtualized clock"
515 select PARAVIRT_CLOCK
517 Turning on this option will allow you to run a paravirtualized clock
518 when running over the KVM hypervisor. Instead of relying on a PIT
519 (or probably other) emulation by the underlying device model, the host
520 provides the guest with timing infrastructure such as time of day, and
524 bool "KVM Guest support"
527 This option enables various optimizations for running under the KVM
530 source "arch/x86/lguest/Kconfig"
533 bool "Enable paravirtualization code"
535 This changes the kernel so it can modify itself when it is run
536 under a hypervisor, potentially improving performance significantly
537 over full virtualization. However, when run without a hypervisor
538 the kernel is theoretically slower and slightly larger.
540 config PARAVIRT_SPINLOCKS
541 bool "Paravirtualization layer for spinlocks"
542 depends on PARAVIRT && SMP && EXPERIMENTAL
544 Paravirtualized spinlocks allow a pvops backend to replace the
545 spinlock implementation with something virtualization-friendly
546 (for example, block the virtual CPU rather than spinning).
548 Unfortunately the downside is an up to 5% performance hit on
549 native kernels, with various workloads.
551 If you are unsure how to answer this question, answer N.
553 config PARAVIRT_CLOCK
558 config PARAVIRT_DEBUG
559 bool "paravirt-ops debugging"
560 depends on PARAVIRT && DEBUG_KERNEL
562 Enable to debug paravirt_ops internals. Specifically, BUG if
563 a paravirt_op is missing when it is called.
571 This option adds a kernel parameter 'memtest', which allows memtest
573 memtest=0, mean disabled; -- default
574 memtest=1, mean do 1 test pattern;
576 memtest=4, mean do 4 test patterns.
577 If you are unsure how to answer this question, answer N.
579 config X86_SUMMIT_NUMA
581 depends on X86_32 && NUMA && X86_32_NON_STANDARD
583 config X86_CYCLONE_TIMER
585 depends on X86_32_NON_STANDARD
587 source "arch/x86/Kconfig.cpu"
591 prompt "HPET Timer Support" if X86_32
593 Use the IA-PC HPET (High Precision Event Timer) to manage
594 time in preference to the PIT and RTC, if a HPET is
596 HPET is the next generation timer replacing legacy 8254s.
597 The HPET provides a stable time base on SMP
598 systems, unlike the TSC, but it is more expensive to access,
599 as it is off-chip. You can find the HPET spec at
600 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
602 You can safely choose Y here. However, HPET will only be
603 activated if the platform and the BIOS support this feature.
604 Otherwise the 8254 will be used for timing services.
606 Choose N to continue using the legacy 8254 timer.
608 config HPET_EMULATE_RTC
610 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
614 prompt "Langwell APB Timer Support" if X86_MRST
616 APB timer is the replacement for 8254, HPET on X86 MID platforms.
617 The APBT provides a stable time base on SMP
618 systems, unlike the TSC, but it is more expensive to access,
619 as it is off-chip. APB timers are always running regardless of CPU
620 C states, they are used as per CPU clockevent device when possible.
622 # Mark as expert because too many people got it wrong.
623 # The code disables itself when not needed.
626 bool "Enable DMI scanning" if EXPERT
628 Enabled scanning of DMI to identify machine quirks. Say Y
629 here unless you have verified that your setup is not
630 affected by entries in the DMI blacklist. Required by PNP
634 bool "GART IOMMU support" if EXPERT
637 depends on X86_64 && PCI && AMD_NB
639 Support for full DMA access of devices with 32bit memory access only
640 on systems with more than 3GB. This is usually needed for USB,
641 sound, many IDE/SATA chipsets and some other devices.
642 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
643 based hardware IOMMU and a software bounce buffer based IOMMU used
644 on Intel systems and as fallback.
645 The code is only active when needed (enough memory and limited
646 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
650 bool "IBM Calgary IOMMU support"
652 depends on X86_64 && PCI && EXPERIMENTAL
654 Support for hardware IOMMUs in IBM's xSeries x366 and x460
655 systems. Needed to run systems with more than 3GB of memory
656 properly with 32-bit PCI devices that do not support DAC
657 (Double Address Cycle). Calgary also supports bus level
658 isolation, where all DMAs pass through the IOMMU. This
659 prevents them from going anywhere except their intended
660 destination. This catches hard-to-find kernel bugs and
661 mis-behaving drivers and devices that do not use the DMA-API
662 properly to set up their DMA buffers. The IOMMU can be
663 turned off at boot time with the iommu=off parameter.
664 Normally the kernel will make the right choice by itself.
667 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
669 prompt "Should Calgary be enabled by default?"
670 depends on CALGARY_IOMMU
672 Should Calgary be enabled by default? if you choose 'y', Calgary
673 will be used (if it exists). If you choose 'n', Calgary will not be
674 used even if it exists. If you choose 'n' and would like to use
675 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
679 bool "AMD IOMMU support"
682 depends on X86_64 && PCI && ACPI
684 With this option you can enable support for AMD IOMMU hardware in
685 your system. An IOMMU is a hardware component which provides
686 remapping of DMA memory accesses from devices. With an AMD IOMMU you
687 can isolate the the DMA memory of different devices and protect the
688 system from misbehaving device drivers or hardware.
690 You can find out if your system has an AMD IOMMU if you look into
691 your BIOS for an option to enable it or if you have an IVRS ACPI
694 config AMD_IOMMU_STATS
695 bool "Export AMD IOMMU statistics to debugfs"
699 This option enables code in the AMD IOMMU driver to collect various
700 statistics about whats happening in the driver and exports that
701 information to userspace via debugfs.
704 # need this always selected by IOMMU for the VIA workaround
708 Support for software bounce buffers used on x86-64 systems
709 which don't have a hardware IOMMU (e.g. the current generation
710 of Intel's x86-64 CPUs). Using this PCI devices which can only
711 access 32-bits of memory can be used on systems with more than
712 3 GB of memory. If unsure, say Y.
715 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
718 def_bool (AMD_IOMMU || DMAR)
721 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
722 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
723 select CPUMASK_OFFSTACK
725 Enable maximum number of CPUS and NUMA Nodes for this architecture.
729 int "Maximum number of CPUs" if SMP && !MAXSMP
730 range 2 8 if SMP && X86_32 && !X86_BIGSMP
731 range 2 512 if SMP && !MAXSMP
733 default "4096" if MAXSMP
734 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
737 This allows you to specify the maximum number of CPUs which this
738 kernel will support. The maximum supported value is 512 and the
739 minimum value which makes sense is 2.
741 This is purely to save memory - each supported CPU adds
742 approximately eight kilobytes to the kernel image.
745 bool "SMT (Hyperthreading) scheduler support"
748 SMT scheduler support improves the CPU scheduler's decision making
749 when dealing with Intel Pentium 4 chips with HyperThreading at a
750 cost of slightly increased overhead in some places. If unsure say
755 prompt "Multi-core scheduler support"
758 Multi-core scheduler support improves the CPU scheduler's decision
759 making when dealing with multi-core CPU chips at a cost of slightly
760 increased overhead in some places. If unsure say N here.
762 config IRQ_TIME_ACCOUNTING
763 bool "Fine granularity task level IRQ time accounting"
766 Select this option to enable fine granularity task irq time
767 accounting. This is done by reading a timestamp on each
768 transitions between softirq and hardirq state, so there can be a
769 small performance impact.
771 If in doubt, say N here.
773 source "kernel/Kconfig.preempt"
776 bool "Local APIC support on uniprocessors"
777 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
779 A local APIC (Advanced Programmable Interrupt Controller) is an
780 integrated interrupt controller in the CPU. If you have a single-CPU
781 system which has a processor with a local APIC, you can say Y here to
782 enable and use it. If you say Y here even though your machine doesn't
783 have a local APIC, then the kernel will still run with no slowdown at
784 all. The local APIC supports CPU-generated self-interrupts (timer,
785 performance counters), and the NMI watchdog which detects hard
789 bool "IO-APIC support on uniprocessors"
790 depends on X86_UP_APIC
792 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
793 SMP-capable replacement for PC-style interrupt controllers. Most
794 SMP systems and many recent uniprocessor systems have one.
796 If you have a single-CPU system with an IO-APIC, you can say Y here
797 to use it. If you say Y here even though your machine doesn't have
798 an IO-APIC, then the kernel will still run with no slowdown at all.
800 config X86_LOCAL_APIC
802 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
806 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
808 config X86_VISWS_APIC
810 depends on X86_32 && X86_VISWS
812 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
813 bool "Reroute for broken boot IRQs"
814 depends on X86_IO_APIC
816 This option enables a workaround that fixes a source of
817 spurious interrupts. This is recommended when threaded
818 interrupt handling is used on systems where the generation of
819 superfluous "boot interrupts" cannot be disabled.
821 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
822 entry in the chipset's IO-APIC is masked (as, e.g. the RT
823 kernel does during interrupt handling). On chipsets where this
824 boot IRQ generation cannot be disabled, this workaround keeps
825 the original IRQ line masked so that only the equivalent "boot
826 IRQ" is delivered to the CPUs. The workaround also tells the
827 kernel to set up the IRQ handler on the boot IRQ line. In this
828 way only one interrupt is delivered to the kernel. Otherwise
829 the spurious second interrupt may cause the kernel to bring
830 down (vital) interrupt lines.
832 Only affects "broken" chipsets. Interrupt sharing may be
833 increased on these systems.
836 bool "Machine Check / overheating reporting"
838 Machine Check support allows the processor to notify the
839 kernel if it detects a problem (e.g. overheating, data corruption).
840 The action the kernel takes depends on the severity of the problem,
841 ranging from warning messages to halting the machine.
845 prompt "Intel MCE features"
846 depends on X86_MCE && X86_LOCAL_APIC
848 Additional support for intel specific MCE features such as
853 prompt "AMD MCE features"
854 depends on X86_MCE && X86_LOCAL_APIC
856 Additional support for AMD specific MCE features such as
857 the DRAM Error Threshold.
859 config X86_ANCIENT_MCE
860 bool "Support for old Pentium 5 / WinChip machine checks"
861 depends on X86_32 && X86_MCE
863 Include support for machine check handling on old Pentium 5 or WinChip
864 systems. These typically need to be enabled explicitely on the command
867 config X86_MCE_THRESHOLD
868 depends on X86_MCE_AMD || X86_MCE_INTEL
871 config X86_MCE_INJECT
873 tristate "Machine check injector support"
875 Provide support for injecting machine checks for testing purposes.
876 If you don't know what a machine check is and you don't do kernel
877 QA it is safe to say n.
879 config X86_THERMAL_VECTOR
881 depends on X86_MCE_INTEL
884 bool "Enable VM86 support" if EXPERT
888 This option is required by programs like DOSEMU to run 16-bit legacy
889 code on X86 processors. It also may be needed by software like
890 XFree86 to initialize some video cards via BIOS. Disabling this
891 option saves about 6k.
894 tristate "Toshiba Laptop support"
897 This adds a driver to safely access the System Management Mode of
898 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
899 not work on models with a Phoenix BIOS. The System Management Mode
900 is used to set the BIOS and power saving options on Toshiba portables.
902 For information on utilities to make use of this driver see the
903 Toshiba Linux utilities web site at:
904 <http://www.buzzard.org.uk/toshiba/>.
906 Say Y if you intend to run this kernel on a Toshiba portable.
910 tristate "Dell laptop support"
912 This adds a driver to safely access the System Management Mode
913 of the CPU on the Dell Inspiron 8000. The System Management Mode
914 is used to read cpu temperature and cooling fan status and to
915 control the fans on the I8K portables.
917 This driver has been tested only on the Inspiron 8000 but it may
918 also work with other Dell laptops. You can force loading on other
919 models by passing the parameter `force=1' to the module. Use at
922 For information on utilities to make use of this driver see the
923 I8K Linux utilities web site at:
924 <http://people.debian.org/~dz/i8k/>
926 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
929 config X86_REBOOTFIXUPS
930 bool "Enable X86 board specific fixups for reboot"
933 This enables chipset and/or board specific fixups to be done
934 in order to get reboot to work correctly. This is only needed on
935 some combinations of hardware and BIOS. The symptom, for which
936 this config is intended, is when reboot ends with a stalled/hung
939 Currently, the only fixup is for the Geode machines using
940 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
942 Say Y if you want to enable the fixup. Currently, it's safe to
943 enable this option even if you don't need it.
947 tristate "/dev/cpu/microcode - microcode support"
950 If you say Y here, you will be able to update the microcode on
951 certain Intel and AMD processors. The Intel support is for the
952 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
953 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
954 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
955 You will obviously need the actual microcode binary data itself
956 which is not shipped with the Linux kernel.
958 This option selects the general module only, you need to select
959 at least one vendor specific module as well.
961 To compile this driver as a module, choose M here: the
962 module will be called microcode.
964 config MICROCODE_INTEL
965 bool "Intel microcode patch loading support"
970 This options enables microcode patch loading support for Intel
973 For latest news and information on obtaining all the required
974 Intel ingredients for this driver, check:
975 <http://www.urbanmyth.org/microcode/>.
978 bool "AMD microcode patch loading support"
982 If you select this option, microcode patch loading support for AMD
983 processors will be enabled.
985 config MICROCODE_OLD_INTERFACE
990 tristate "/dev/cpu/*/msr - Model-specific register support"
992 This device gives privileged processes access to the x86
993 Model-Specific Registers (MSRs). It is a character device with
994 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
995 MSR accesses are directed to a specific CPU on multi-processor
999 tristate "/dev/cpu/*/cpuid - CPU information support"
1001 This device gives processes access to the x86 CPUID instruction to
1002 be executed on a specific processor. It is a character device
1003 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1007 prompt "High Memory Support"
1008 default HIGHMEM64G if X86_NUMAQ
1014 depends on !X86_NUMAQ
1016 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1017 However, the address space of 32-bit x86 processors is only 4
1018 Gigabytes large. That means that, if you have a large amount of
1019 physical memory, not all of it can be "permanently mapped" by the
1020 kernel. The physical memory that's not permanently mapped is called
1023 If you are compiling a kernel which will never run on a machine with
1024 more than 1 Gigabyte total physical RAM, answer "off" here (default
1025 choice and suitable for most users). This will result in a "3GB/1GB"
1026 split: 3GB are mapped so that each process sees a 3GB virtual memory
1027 space and the remaining part of the 4GB virtual memory space is used
1028 by the kernel to permanently map as much physical memory as
1031 If the machine has between 1 and 4 Gigabytes physical RAM, then
1034 If more than 4 Gigabytes is used then answer "64GB" here. This
1035 selection turns Intel PAE (Physical Address Extension) mode on.
1036 PAE implements 3-level paging on IA32 processors. PAE is fully
1037 supported by Linux, PAE mode is implemented on all recent Intel
1038 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1039 then the kernel will not boot on CPUs that don't support PAE!
1041 The actual amount of total physical memory will either be
1042 auto detected or can be forced by using a kernel command line option
1043 such as "mem=256M". (Try "man bootparam" or see the documentation of
1044 your boot loader (lilo or loadlin) about how to pass options to the
1045 kernel at boot time.)
1047 If unsure, say "off".
1051 depends on !X86_NUMAQ
1053 Select this if you have a 32-bit processor and between 1 and 4
1054 gigabytes of physical RAM.
1058 depends on !M386 && !M486
1061 Select this if you have a 32-bit processor and more than 4
1062 gigabytes of physical RAM.
1067 depends on EXPERIMENTAL
1068 prompt "Memory split" if EXPERT
1072 Select the desired split between kernel and user memory.
1074 If the address range available to the kernel is less than the
1075 physical memory installed, the remaining memory will be available
1076 as "high memory". Accessing high memory is a little more costly
1077 than low memory, as it needs to be mapped into the kernel first.
1078 Note that increasing the kernel address space limits the range
1079 available to user programs, making the address space there
1080 tighter. Selecting anything other than the default 3G/1G split
1081 will also likely make your kernel incompatible with binary-only
1084 If you are not absolutely sure what you are doing, leave this
1088 bool "3G/1G user/kernel split"
1089 config VMSPLIT_3G_OPT
1091 bool "3G/1G user/kernel split (for full 1G low memory)"
1093 bool "2G/2G user/kernel split"
1094 config VMSPLIT_2G_OPT
1096 bool "2G/2G user/kernel split (for full 2G low memory)"
1098 bool "1G/3G user/kernel split"
1103 default 0xB0000000 if VMSPLIT_3G_OPT
1104 default 0x80000000 if VMSPLIT_2G
1105 default 0x78000000 if VMSPLIT_2G_OPT
1106 default 0x40000000 if VMSPLIT_1G
1112 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1115 bool "PAE (Physical Address Extension) Support"
1116 depends on X86_32 && !HIGHMEM4G
1118 PAE is required for NX support, and furthermore enables
1119 larger swapspace support for non-overcommit purposes. It
1120 has the cost of more pagetable lookup overhead, and also
1121 consumes more pagetable space per process.
1123 config ARCH_PHYS_ADDR_T_64BIT
1124 def_bool X86_64 || X86_PAE
1126 config ARCH_DMA_ADDR_T_64BIT
1127 def_bool X86_64 || HIGHMEM64G
1129 config DIRECT_GBPAGES
1130 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1134 Allow the kernel linear mapping to use 1GB pages on CPUs that
1135 support it. This can improve the kernel's performance a tiny bit by
1136 reducing TLB pressure. If in doubt, say "Y".
1138 # Common NUMA Features
1140 bool "Numa Memory Allocation and Scheduler Support"
1142 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1143 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1145 Enable NUMA (Non Uniform Memory Access) support.
1147 The kernel will try to allocate memory used by a CPU on the
1148 local memory controller of the CPU and add some more
1149 NUMA awareness to the kernel.
1151 For 64-bit this is recommended if the system is Intel Core i7
1152 (or later), AMD Opteron, or EM64T NUMA.
1154 For 32-bit this is only needed on (rare) 32-bit-only platforms
1155 that support NUMA topologies, such as NUMAQ / Summit, or if you
1156 boot a 32-bit kernel on a 64-bit NUMA platform.
1158 Otherwise, you should say N.
1160 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1161 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1165 prompt "Old style AMD Opteron NUMA detection"
1166 depends on X86_64 && NUMA && PCI
1168 Enable AMD NUMA node topology detection. You should say Y here if
1169 you have a multi processor AMD system. This uses an old method to
1170 read the NUMA configuration directly from the builtin Northbridge
1171 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1172 which also takes priority if both are compiled in.
1174 config X86_64_ACPI_NUMA
1176 prompt "ACPI NUMA detection"
1177 depends on X86_64 && NUMA && ACPI && PCI
1180 Enable ACPI SRAT based node topology detection.
1182 # Some NUMA nodes have memory ranges that span
1183 # other nodes. Even though a pfn is valid and
1184 # between a node's start and end pfns, it may not
1185 # reside on that node. See memmap_init_zone()
1187 config NODES_SPAN_OTHER_NODES
1189 depends on X86_64_ACPI_NUMA
1192 bool "NUMA emulation"
1193 depends on X86_64 && NUMA
1195 Enable NUMA emulation. A flat machine will be split
1196 into virtual nodes when booted with "numa=fake=N", where N is the
1197 number of nodes. This is only useful for debugging.
1200 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1202 default "10" if MAXSMP
1203 default "6" if X86_64
1204 default "4" if X86_NUMAQ
1206 depends on NEED_MULTIPLE_NODES
1208 Specify the maximum number of NUMA Nodes available on the target
1209 system. Increases memory reserved to accommodate various tables.
1211 config HAVE_ARCH_BOOTMEM
1213 depends on X86_32 && NUMA
1215 config ARCH_HAVE_MEMORY_PRESENT
1217 depends on X86_32 && DISCONTIGMEM
1219 config NEED_NODE_MEMMAP_SIZE
1221 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1223 config HAVE_ARCH_ALLOC_REMAP
1225 depends on X86_32 && NUMA
1227 config ARCH_FLATMEM_ENABLE
1229 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1231 config ARCH_DISCONTIGMEM_ENABLE
1233 depends on NUMA && X86_32
1235 config ARCH_DISCONTIGMEM_DEFAULT
1237 depends on NUMA && X86_32
1239 config ARCH_PROC_KCORE_TEXT
1241 depends on X86_64 && PROC_KCORE
1243 config ARCH_SPARSEMEM_DEFAULT
1247 config ARCH_SPARSEMEM_ENABLE
1249 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1250 select SPARSEMEM_STATIC if X86_32
1251 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1253 config ARCH_SELECT_MEMORY_MODEL
1255 depends on ARCH_SPARSEMEM_ENABLE
1257 config ARCH_MEMORY_PROBE
1259 depends on MEMORY_HOTPLUG
1261 config ILLEGAL_POINTER_VALUE
1264 default 0xdead000000000000 if X86_64
1269 bool "Allocate 3rd-level pagetables from highmem"
1272 The VM uses one page table entry for each page of physical memory.
1273 For systems with a lot of RAM, this can be wasteful of precious
1274 low memory. Setting this option will put user-space page table
1275 entries in high memory.
1277 config X86_CHECK_BIOS_CORRUPTION
1278 bool "Check for low memory corruption"
1280 Periodically check for memory corruption in low memory, which
1281 is suspected to be caused by BIOS. Even when enabled in the
1282 configuration, it is disabled at runtime. Enable it by
1283 setting "memory_corruption_check=1" on the kernel command
1284 line. By default it scans the low 64k of memory every 60
1285 seconds; see the memory_corruption_check_size and
1286 memory_corruption_check_period parameters in
1287 Documentation/kernel-parameters.txt to adjust this.
1289 When enabled with the default parameters, this option has
1290 almost no overhead, as it reserves a relatively small amount
1291 of memory and scans it infrequently. It both detects corruption
1292 and prevents it from affecting the running system.
1294 It is, however, intended as a diagnostic tool; if repeatable
1295 BIOS-originated corruption always affects the same memory,
1296 you can use memmap= to prevent the kernel from using that
1299 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1300 bool "Set the default setting of memory_corruption_check"
1301 depends on X86_CHECK_BIOS_CORRUPTION
1304 Set whether the default state of memory_corruption_check is
1307 config X86_RESERVE_LOW
1308 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1312 Specify the amount of low memory to reserve for the BIOS.
1314 The first page contains BIOS data structures that the kernel
1315 must not use, so that page must always be reserved.
1317 By default we reserve the first 64K of physical RAM, as a
1318 number of BIOSes are known to corrupt that memory range
1319 during events such as suspend/resume or monitor cable
1320 insertion, so it must not be used by the kernel.
1322 You can set this to 4 if you are absolutely sure that you
1323 trust the BIOS to get all its memory reservations and usages
1324 right. If you know your BIOS have problems beyond the
1325 default 64K area, you can set this to 640 to avoid using the
1326 entire low memory range.
1328 If you have doubts about the BIOS (e.g. suspend/resume does
1329 not work or there's kernel crashes after certain hardware
1330 hotplug events) then you might want to enable
1331 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1332 typical corruption patterns.
1334 Leave this to the default value of 64 if you are unsure.
1336 config MATH_EMULATION
1338 prompt "Math emulation" if X86_32
1340 Linux can emulate a math coprocessor (used for floating point
1341 operations) if you don't have one. 486DX and Pentium processors have
1342 a math coprocessor built in, 486SX and 386 do not, unless you added
1343 a 487DX or 387, respectively. (The messages during boot time can
1344 give you some hints here ["man dmesg"].) Everyone needs either a
1345 coprocessor or this emulation.
1347 If you don't have a math coprocessor, you need to say Y here; if you
1348 say Y here even though you have a coprocessor, the coprocessor will
1349 be used nevertheless. (This behavior can be changed with the kernel
1350 command line option "no387", which comes handy if your coprocessor
1351 is broken. Try "man bootparam" or see the documentation of your boot
1352 loader (lilo or loadlin) about how to pass options to the kernel at
1353 boot time.) This means that it is a good idea to say Y here if you
1354 intend to use this kernel on different machines.
1356 More information about the internals of the Linux math coprocessor
1357 emulation can be found in <file:arch/x86/math-emu/README>.
1359 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1360 kernel, it won't hurt.
1364 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1366 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1367 the Memory Type Range Registers (MTRRs) may be used to control
1368 processor access to memory ranges. This is most useful if you have
1369 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1370 allows bus write transfers to be combined into a larger transfer
1371 before bursting over the PCI/AGP bus. This can increase performance
1372 of image write operations 2.5 times or more. Saying Y here creates a
1373 /proc/mtrr file which may be used to manipulate your processor's
1374 MTRRs. Typically the X server should use this.
1376 This code has a reasonably generic interface so that similar
1377 control registers on other processors can be easily supported
1380 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1381 Registers (ARRs) which provide a similar functionality to MTRRs. For
1382 these, the ARRs are used to emulate the MTRRs.
1383 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1384 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1385 write-combining. All of these processors are supported by this code
1386 and it makes sense to say Y here if you have one of them.
1388 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1389 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1390 can lead to all sorts of problems, so it's good to say Y here.
1392 You can safely say Y even if your machine doesn't have MTRRs, you'll
1393 just add about 9 KB to your kernel.
1395 See <file:Documentation/x86/mtrr.txt> for more information.
1397 config MTRR_SANITIZER
1399 prompt "MTRR cleanup support"
1402 Convert MTRR layout from continuous to discrete, so X drivers can
1403 add writeback entries.
1405 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1406 The largest mtrr entry size for a continuous block can be set with
1411 config MTRR_SANITIZER_ENABLE_DEFAULT
1412 int "MTRR cleanup enable value (0-1)"
1415 depends on MTRR_SANITIZER
1417 Enable mtrr cleanup default value
1419 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1420 int "MTRR cleanup spare reg num (0-7)"
1423 depends on MTRR_SANITIZER
1425 mtrr cleanup spare entries default, it can be changed via
1426 mtrr_spare_reg_nr=N on the kernel command line.
1430 prompt "x86 PAT support" if EXPERT
1433 Use PAT attributes to setup page level cache control.
1435 PATs are the modern equivalents of MTRRs and are much more
1436 flexible than MTRRs.
1438 Say N here if you see bootup problems (boot crash, boot hang,
1439 spontaneous reboots) or a non-working video driver.
1443 config ARCH_USES_PG_UNCACHED
1448 bool "EFI runtime service support"
1451 This enables the kernel to use EFI runtime services that are
1452 available (such as the EFI variable services).
1454 This option is only useful on systems that have EFI firmware.
1455 In addition, you should use the latest ELILO loader available
1456 at <http://elilo.sourceforge.net> in order to take advantage
1457 of EFI runtime services. However, even with this option, the
1458 resultant kernel should continue to boot on existing non-EFI
1463 prompt "Enable seccomp to safely compute untrusted bytecode"
1465 This kernel feature is useful for number crunching applications
1466 that may need to compute untrusted bytecode during their
1467 execution. By using pipes or other transports made available to
1468 the process as file descriptors supporting the read/write
1469 syscalls, it's possible to isolate those applications in
1470 their own address space using seccomp. Once seccomp is
1471 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1472 and the task is only allowed to execute a few safe syscalls
1473 defined by each seccomp mode.
1475 If unsure, say Y. Only embedded should say N here.
1477 config CC_STACKPROTECTOR
1478 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1480 This option turns on the -fstack-protector GCC feature. This
1481 feature puts, at the beginning of functions, a canary value on
1482 the stack just before the return address, and validates
1483 the value just before actually returning. Stack based buffer
1484 overflows (that need to overwrite this return address) now also
1485 overwrite the canary, which gets detected and the attack is then
1486 neutralized via a kernel panic.
1488 This feature requires gcc version 4.2 or above, or a distribution
1489 gcc with the feature backported. Older versions are automatically
1490 detected and for those versions, this configuration option is
1491 ignored. (and a warning is printed during bootup)
1493 source kernel/Kconfig.hz
1496 bool "kexec system call"
1498 kexec is a system call that implements the ability to shutdown your
1499 current kernel, and to start another kernel. It is like a reboot
1500 but it is independent of the system firmware. And like a reboot
1501 you can start any kernel with it, not just Linux.
1503 The name comes from the similarity to the exec system call.
1505 It is an ongoing process to be certain the hardware in a machine
1506 is properly shutdown, so do not be surprised if this code does not
1507 initially work for you. It may help to enable device hotplugging
1508 support. As of this writing the exact hardware interface is
1509 strongly in flux, so no good recommendation can be made.
1512 bool "kernel crash dumps"
1513 depends on X86_64 || (X86_32 && HIGHMEM)
1515 Generate crash dump after being started by kexec.
1516 This should be normally only set in special crash dump kernels
1517 which are loaded in the main kernel with kexec-tools into
1518 a specially reserved region and then later executed after
1519 a crash by kdump/kexec. The crash dump kernel must be compiled
1520 to a memory address not used by the main kernel or BIOS using
1521 PHYSICAL_START, or it must be built as a relocatable image
1522 (CONFIG_RELOCATABLE=y).
1523 For more details see Documentation/kdump/kdump.txt
1526 bool "kexec jump (EXPERIMENTAL)"
1527 depends on EXPERIMENTAL
1528 depends on KEXEC && HIBERNATION
1530 Jump between original kernel and kexeced kernel and invoke
1531 code in physical address mode via KEXEC
1533 config PHYSICAL_START
1534 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1537 This gives the physical address where the kernel is loaded.
1539 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1540 bzImage will decompress itself to above physical address and
1541 run from there. Otherwise, bzImage will run from the address where
1542 it has been loaded by the boot loader and will ignore above physical
1545 In normal kdump cases one does not have to set/change this option
1546 as now bzImage can be compiled as a completely relocatable image
1547 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1548 address. This option is mainly useful for the folks who don't want
1549 to use a bzImage for capturing the crash dump and want to use a
1550 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1551 to be specifically compiled to run from a specific memory area
1552 (normally a reserved region) and this option comes handy.
1554 So if you are using bzImage for capturing the crash dump,
1555 leave the value here unchanged to 0x1000000 and set
1556 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1557 for capturing the crash dump change this value to start of
1558 the reserved region. In other words, it can be set based on
1559 the "X" value as specified in the "crashkernel=YM@XM"
1560 command line boot parameter passed to the panic-ed
1561 kernel. Please take a look at Documentation/kdump/kdump.txt
1562 for more details about crash dumps.
1564 Usage of bzImage for capturing the crash dump is recommended as
1565 one does not have to build two kernels. Same kernel can be used
1566 as production kernel and capture kernel. Above option should have
1567 gone away after relocatable bzImage support is introduced. But it
1568 is present because there are users out there who continue to use
1569 vmlinux for dump capture. This option should go away down the
1572 Don't change this unless you know what you are doing.
1575 bool "Build a relocatable kernel"
1578 This builds a kernel image that retains relocation information
1579 so it can be loaded someplace besides the default 1MB.
1580 The relocations tend to make the kernel binary about 10% larger,
1581 but are discarded at runtime.
1583 One use is for the kexec on panic case where the recovery kernel
1584 must live at a different physical address than the primary
1587 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1588 it has been loaded at and the compile time physical address
1589 (CONFIG_PHYSICAL_START) is ignored.
1591 # Relocation on x86-32 needs some additional build support
1592 config X86_NEED_RELOCS
1594 depends on X86_32 && RELOCATABLE
1596 config PHYSICAL_ALIGN
1597 hex "Alignment value to which kernel should be aligned" if X86_32
1599 range 0x2000 0x1000000
1601 This value puts the alignment restrictions on physical address
1602 where kernel is loaded and run from. Kernel is compiled for an
1603 address which meets above alignment restriction.
1605 If bootloader loads the kernel at a non-aligned address and
1606 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1607 address aligned to above value and run from there.
1609 If bootloader loads the kernel at a non-aligned address and
1610 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1611 load address and decompress itself to the address it has been
1612 compiled for and run from there. The address for which kernel is
1613 compiled already meets above alignment restrictions. Hence the
1614 end result is that kernel runs from a physical address meeting
1615 above alignment restrictions.
1617 Don't change this unless you know what you are doing.
1620 bool "Support for hot-pluggable CPUs"
1621 depends on SMP && HOTPLUG
1623 Say Y here to allow turning CPUs off and on. CPUs can be
1624 controlled through /sys/devices/system/cpu.
1625 ( Note: power management support will enable this option
1626 automatically on SMP systems. )
1627 Say N if you want to disable CPU hotplug.
1631 prompt "Compat VDSO support"
1632 depends on X86_32 || IA32_EMULATION
1634 Map the 32-bit VDSO to the predictable old-style address too.
1636 Say N here if you are running a sufficiently recent glibc
1637 version (2.3.3 or later), to remove the high-mapped
1638 VDSO mapping and to exclusively use the randomized VDSO.
1643 bool "Built-in kernel command line"
1645 Allow for specifying boot arguments to the kernel at
1646 build time. On some systems (e.g. embedded ones), it is
1647 necessary or convenient to provide some or all of the
1648 kernel boot arguments with the kernel itself (that is,
1649 to not rely on the boot loader to provide them.)
1651 To compile command line arguments into the kernel,
1652 set this option to 'Y', then fill in the
1653 the boot arguments in CONFIG_CMDLINE.
1655 Systems with fully functional boot loaders (i.e. non-embedded)
1656 should leave this option set to 'N'.
1659 string "Built-in kernel command string"
1660 depends on CMDLINE_BOOL
1663 Enter arguments here that should be compiled into the kernel
1664 image and used at boot time. If the boot loader provides a
1665 command line at boot time, it is appended to this string to
1666 form the full kernel command line, when the system boots.
1668 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1669 change this behavior.
1671 In most cases, the command line (whether built-in or provided
1672 by the boot loader) should specify the device for the root
1675 config CMDLINE_OVERRIDE
1676 bool "Built-in command line overrides boot loader arguments"
1677 depends on CMDLINE_BOOL
1679 Set this option to 'Y' to have the kernel ignore the boot loader
1680 command line, and use ONLY the built-in command line.
1682 This is used to work around broken boot loaders. This should
1683 be set to 'N' under normal conditions.
1687 config ARCH_ENABLE_MEMORY_HOTPLUG
1689 depends on X86_64 || (X86_32 && HIGHMEM)
1691 config ARCH_ENABLE_MEMORY_HOTREMOVE
1693 depends on MEMORY_HOTPLUG
1695 config HAVE_ARCH_EARLY_PFN_TO_NID
1699 config USE_PERCPU_NUMA_NODE_ID
1703 menu "Power management and ACPI options"
1705 config ARCH_HIBERNATION_HEADER
1707 depends on X86_64 && HIBERNATION
1709 source "kernel/power/Kconfig"
1711 source "drivers/acpi/Kconfig"
1713 source "drivers/sfi/Kconfig"
1717 depends on APM || APM_MODULE
1720 tristate "APM (Advanced Power Management) BIOS support"
1721 depends on X86_32 && PM_SLEEP
1723 APM is a BIOS specification for saving power using several different
1724 techniques. This is mostly useful for battery powered laptops with
1725 APM compliant BIOSes. If you say Y here, the system time will be
1726 reset after a RESUME operation, the /proc/apm device will provide
1727 battery status information, and user-space programs will receive
1728 notification of APM "events" (e.g. battery status change).
1730 If you select "Y" here, you can disable actual use of the APM
1731 BIOS by passing the "apm=off" option to the kernel at boot time.
1733 Note that the APM support is almost completely disabled for
1734 machines with more than one CPU.
1736 In order to use APM, you will need supporting software. For location
1737 and more information, read <file:Documentation/power/pm.txt> and the
1738 Battery Powered Linux mini-HOWTO, available from
1739 <http://www.tldp.org/docs.html#howto>.
1741 This driver does not spin down disk drives (see the hdparm(8)
1742 manpage ("man 8 hdparm") for that), and it doesn't turn off
1743 VESA-compliant "green" monitors.
1745 This driver does not support the TI 4000M TravelMate and the ACER
1746 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1747 desktop machines also don't have compliant BIOSes, and this driver
1748 may cause those machines to panic during the boot phase.
1750 Generally, if you don't have a battery in your machine, there isn't
1751 much point in using this driver and you should say N. If you get
1752 random kernel OOPSes or reboots that don't seem to be related to
1753 anything, try disabling/enabling this option (or disabling/enabling
1756 Some other things you should try when experiencing seemingly random,
1759 1) make sure that you have enough swap space and that it is
1761 2) pass the "no-hlt" option to the kernel
1762 3) switch on floating point emulation in the kernel and pass
1763 the "no387" option to the kernel
1764 4) pass the "floppy=nodma" option to the kernel
1765 5) pass the "mem=4M" option to the kernel (thereby disabling
1766 all but the first 4 MB of RAM)
1767 6) make sure that the CPU is not over clocked.
1768 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1769 8) disable the cache from your BIOS settings
1770 9) install a fan for the video card or exchange video RAM
1771 10) install a better fan for the CPU
1772 11) exchange RAM chips
1773 12) exchange the motherboard.
1775 To compile this driver as a module, choose M here: the
1776 module will be called apm.
1780 config APM_IGNORE_USER_SUSPEND
1781 bool "Ignore USER SUSPEND"
1783 This option will ignore USER SUSPEND requests. On machines with a
1784 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1785 series notebooks, it is necessary to say Y because of a BIOS bug.
1787 config APM_DO_ENABLE
1788 bool "Enable PM at boot time"
1790 Enable APM features at boot time. From page 36 of the APM BIOS
1791 specification: "When disabled, the APM BIOS does not automatically
1792 power manage devices, enter the Standby State, enter the Suspend
1793 State, or take power saving steps in response to CPU Idle calls."
1794 This driver will make CPU Idle calls when Linux is idle (unless this
1795 feature is turned off -- see "Do CPU IDLE calls", below). This
1796 should always save battery power, but more complicated APM features
1797 will be dependent on your BIOS implementation. You may need to turn
1798 this option off if your computer hangs at boot time when using APM
1799 support, or if it beeps continuously instead of suspending. Turn
1800 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1801 T400CDT. This is off by default since most machines do fine without
1805 bool "Make CPU Idle calls when idle"
1807 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1808 On some machines, this can activate improved power savings, such as
1809 a slowed CPU clock rate, when the machine is idle. These idle calls
1810 are made after the idle loop has run for some length of time (e.g.,
1811 333 mS). On some machines, this will cause a hang at boot time or
1812 whenever the CPU becomes idle. (On machines with more than one CPU,
1813 this option does nothing.)
1815 config APM_DISPLAY_BLANK
1816 bool "Enable console blanking using APM"
1818 Enable console blanking using the APM. Some laptops can use this to
1819 turn off the LCD backlight when the screen blanker of the Linux
1820 virtual console blanks the screen. Note that this is only used by
1821 the virtual console screen blanker, and won't turn off the backlight
1822 when using the X Window system. This also doesn't have anything to
1823 do with your VESA-compliant power-saving monitor. Further, this
1824 option doesn't work for all laptops -- it might not turn off your
1825 backlight at all, or it might print a lot of errors to the console,
1826 especially if you are using gpm.
1828 config APM_ALLOW_INTS
1829 bool "Allow interrupts during APM BIOS calls"
1831 Normally we disable external interrupts while we are making calls to
1832 the APM BIOS as a measure to lessen the effects of a badly behaving
1833 BIOS implementation. The BIOS should reenable interrupts if it
1834 needs to. Unfortunately, some BIOSes do not -- especially those in
1835 many of the newer IBM Thinkpads. If you experience hangs when you
1836 suspend, try setting this to Y. Otherwise, say N.
1840 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1842 source "drivers/cpuidle/Kconfig"
1844 source "drivers/idle/Kconfig"
1849 menu "Bus options (PCI etc.)"
1854 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1856 Find out whether you have a PCI motherboard. PCI is the name of a
1857 bus system, i.e. the way the CPU talks to the other stuff inside
1858 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1859 VESA. If you have PCI, say Y, otherwise N.
1862 prompt "PCI access mode"
1863 depends on X86_32 && PCI
1866 On PCI systems, the BIOS can be used to detect the PCI devices and
1867 determine their configuration. However, some old PCI motherboards
1868 have BIOS bugs and may crash if this is done. Also, some embedded
1869 PCI-based systems don't have any BIOS at all. Linux can also try to
1870 detect the PCI hardware directly without using the BIOS.
1872 With this option, you can specify how Linux should detect the
1873 PCI devices. If you choose "BIOS", the BIOS will be used,
1874 if you choose "Direct", the BIOS won't be used, and if you
1875 choose "MMConfig", then PCI Express MMCONFIG will be used.
1876 If you choose "Any", the kernel will try MMCONFIG, then the
1877 direct access method and falls back to the BIOS if that doesn't
1878 work. If unsure, go with the default, which is "Any".
1883 config PCI_GOMMCONFIG
1900 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1902 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1905 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1909 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1913 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1917 depends on PCI && XEN
1925 bool "Support mmconfig PCI config space access"
1926 depends on X86_64 && PCI && ACPI
1928 config PCI_CNB20LE_QUIRK
1929 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1931 depends on PCI && EXPERIMENTAL
1933 Read the PCI windows out of the CNB20LE host bridge. This allows
1934 PCI hotplug to work on systems with the CNB20LE chipset which do
1937 There's no public spec for this chipset, and this functionality
1938 is known to be incomplete.
1940 You should say N unless you know you need this.
1943 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1944 depends on PCI_MSI && ACPI && EXPERIMENTAL
1946 DMA remapping (DMAR) devices support enables independent address
1947 translations for Direct Memory Access (DMA) from devices.
1948 These DMA remapping devices are reported via ACPI tables
1949 and include PCI device scope covered by these DMA
1952 config DMAR_DEFAULT_ON
1954 prompt "Enable DMA Remapping Devices by default"
1957 Selecting this option will enable a DMAR device at boot time if
1958 one is found. If this option is not selected, DMAR support can
1959 be enabled by passing intel_iommu=on to the kernel. It is
1960 recommended you say N here while the DMAR code remains
1963 config DMAR_BROKEN_GFX_WA
1964 bool "Workaround broken graphics drivers (going away soon)"
1965 depends on DMAR && BROKEN
1967 Current Graphics drivers tend to use physical address
1968 for DMA and avoid using DMA APIs. Setting this config
1969 option permits the IOMMU driver to set a unity map for
1970 all the OS-visible memory. Hence the driver can continue
1971 to use physical addresses for DMA, at least until this
1972 option is removed in the 2.6.32 kernel.
1974 config DMAR_FLOPPY_WA
1978 Floppy disk drivers are known to bypass DMA API calls
1979 thereby failing to work when IOMMU is enabled. This
1980 workaround will setup a 1:1 mapping for the first
1981 16MiB to make floppy (an ISA device) work.
1984 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1985 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1987 Supports Interrupt remapping for IO-APIC and MSI devices.
1988 To use x2apic mode in the CPU's which support x2APIC enhancements or
1989 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1991 source "drivers/pci/pcie/Kconfig"
1993 source "drivers/pci/Kconfig"
1995 # x86_64 have no ISA slots, but can have ISA-style DMA.
1997 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2000 Enables ISA-style DMA support for devices requiring such controllers.
2008 Find out whether you have ISA slots on your motherboard. ISA is the
2009 name of a bus system, i.e. the way the CPU talks to the other stuff
2010 inside your box. Other bus systems are PCI, EISA, MicroChannel
2011 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2012 newer boards don't support it. If you have ISA, say Y, otherwise N.
2018 The Extended Industry Standard Architecture (EISA) bus was
2019 developed as an open alternative to the IBM MicroChannel bus.
2021 The EISA bus provided some of the features of the IBM MicroChannel
2022 bus while maintaining backward compatibility with cards made for
2023 the older ISA bus. The EISA bus saw limited use between 1988 and
2024 1995 when it was made obsolete by the PCI bus.
2026 Say Y here if you are building a kernel for an EISA-based machine.
2030 source "drivers/eisa/Kconfig"
2035 MicroChannel Architecture is found in some IBM PS/2 machines and
2036 laptops. It is a bus system similar to PCI or ISA. See
2037 <file:Documentation/mca.txt> (and especially the web page given
2038 there) before attempting to build an MCA bus kernel.
2040 source "drivers/mca/Kconfig"
2043 tristate "NatSemi SCx200 support"
2045 This provides basic support for National Semiconductor's
2046 (now AMD's) Geode processors. The driver probes for the
2047 PCI-IDs of several on-chip devices, so its a good dependency
2048 for other scx200_* drivers.
2050 If compiled as a module, the driver is named scx200.
2052 config SCx200HR_TIMER
2053 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2057 This driver provides a clocksource built upon the on-chip
2058 27MHz high-resolution timer. Its also a workaround for
2059 NSC Geode SC-1100's buggy TSC, which loses time when the
2060 processor goes idle (as is done by the scheduler). The
2061 other workaround is idle=poll boot option.
2064 bool "One Laptop Per Child support"
2068 select OF_PROMTREE if PROC_DEVICETREE
2070 Add support for detecting the unique features of the OLPC
2074 tristate "OLPC XO-1 support"
2075 depends on OLPC && MFD_CS5535
2077 Add support for non-essential features of the OLPC XO-1 laptop.
2083 depends on CPU_SUP_AMD && PCI
2085 source "drivers/pcmcia/Kconfig"
2087 source "drivers/pci/hotplug/Kconfig"
2090 bool "RapidIO support"
2094 If you say Y here, the kernel will include drivers and
2095 infrastructure code to support RapidIO interconnect devices.
2097 source "drivers/rapidio/Kconfig"
2102 menu "Executable file formats / Emulations"
2104 source "fs/Kconfig.binfmt"
2106 config IA32_EMULATION
2107 bool "IA32 Emulation"
2109 select COMPAT_BINFMT_ELF
2111 Include code to run 32-bit programs under a 64-bit kernel. You should
2112 likely turn this on, unless you're 100% sure that you don't have any
2113 32-bit programs left.
2116 tristate "IA32 a.out support"
2117 depends on IA32_EMULATION
2119 Support old a.out binaries in the 32bit emulation.
2123 depends on IA32_EMULATION
2125 config COMPAT_FOR_U64_ALIGNMENT
2129 config SYSVIPC_COMPAT
2131 depends on COMPAT && SYSVIPC
2135 depends on COMPAT && KEYS
2141 config HAVE_ATOMIC_IOMAP
2145 config HAVE_TEXT_POKE_SMP
2147 select STOP_MACHINE if SMP
2149 source "net/Kconfig"
2151 source "drivers/Kconfig"
2153 source "drivers/firmware/Kconfig"
2157 source "arch/x86/Kconfig.debug"
2159 source "security/Kconfig"
2161 source "crypto/Kconfig"
2163 source "arch/x86/kvm/Kconfig"
2165 source "lib/Kconfig"