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
19 select HAVE_AOUT if X86_32
20 select HAVE_UNSTABLE_SCHED_CLOCK
23 select HAVE_PCSPKR_PLATFORM
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
68 select GENERIC_FIND_FIRST_BIT
69 select GENERIC_IRQ_PROBE
70 select GENERIC_PENDING_IRQ if SMP
71 select GENERIC_IRQ_SHOW
72 select GENERIC_CLOCKEVENTS_MIN_ADJUST
73 select IRQ_FORCED_THREADING
74 select USE_GENERIC_SMP_HELPERS if SMP
75 select HAVE_BPF_JIT if (X86_64 && NET)
77 select ARCH_HAVE_NMI_SAFE_CMPXCHG
78 select ARCH_SUPPORTS_ATOMIC_RMW
80 config INSTRUCTION_DECODER
81 def_bool (KPROBES || PERF_EVENTS)
85 default "elf32-i386" if X86_32
86 default "elf64-x86-64" if X86_64
90 default "arch/x86/configs/i386_defconfig" if X86_32
91 default "arch/x86/configs/x86_64_defconfig" if X86_64
93 config GENERIC_CMOS_UPDATE
96 config CLOCKSOURCE_WATCHDOG
99 config GENERIC_CLOCKEVENTS
102 config ARCH_CLOCKSOURCE_DATA
106 config GENERIC_CLOCKEVENTS_BROADCAST
108 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
110 config LOCKDEP_SUPPORT
113 config STACKTRACE_SUPPORT
116 config HAVE_LATENCYTOP_SUPPORT
123 bool "DMA memory allocation support" if EXPERT
126 DMA memory allocation support allows devices with less than 32-bit
127 addressing to allocate within the first 16MB of address space.
128 Disable if no such devices will be used.
135 config NEED_DMA_MAP_STATE
137 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
139 config NEED_SG_DMA_LENGTH
142 config GENERIC_ISA_DMA
151 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
153 config GENERIC_BUG_RELATIVE_POINTERS
156 config GENERIC_HWEIGHT
162 config ARCH_MAY_HAVE_PC_FDC
165 config RWSEM_GENERIC_SPINLOCK
168 config RWSEM_XCHGADD_ALGORITHM
171 config ARCH_HAS_CPU_IDLE_WAIT
174 config GENERIC_CALIBRATE_DELAY
177 config GENERIC_TIME_VSYSCALL
181 config ARCH_HAS_CPU_RELAX
184 config ARCH_HAS_DEFAULT_IDLE
187 config ARCH_HAS_CACHE_LINE_SIZE
190 config HAVE_SETUP_PER_CPU_AREA
193 config NEED_PER_CPU_EMBED_FIRST_CHUNK
196 config NEED_PER_CPU_PAGE_FIRST_CHUNK
199 config ARCH_HIBERNATION_POSSIBLE
202 config ARCH_SUSPEND_POSSIBLE
209 config ARCH_POPULATES_NODE_MAP
216 config ARCH_SUPPORTS_OPTIMIZED_INLINING
219 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
222 config HAVE_INTEL_TXT
224 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
228 depends on X86_32 && SMP
232 depends on X86_64 && SMP
238 config X86_32_LAZY_GS
240 depends on X86_32 && !CC_STACKPROTECTOR
242 config ARCH_HWEIGHT_CFLAGS
244 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
245 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
250 config ARCH_CPU_PROBE_RELEASE
252 depends on HOTPLUG_CPU
254 source "init/Kconfig"
255 source "kernel/Kconfig.freezer"
257 menu "Processor type and features"
259 source "kernel/time/Kconfig"
262 bool "Symmetric multi-processing support"
264 This enables support for systems with more than one CPU. If you have
265 a system with only one CPU, like most personal computers, say N. If
266 you have a system with more than one CPU, say Y.
268 If you say N here, the kernel will run on single and multiprocessor
269 machines, but will use only one CPU of a multiprocessor machine. If
270 you say Y here, the kernel will run on many, but not all,
271 singleprocessor machines. On a singleprocessor machine, the kernel
272 will run faster if you say N here.
274 Note that if you say Y here and choose architecture "586" or
275 "Pentium" under "Processor family", the kernel will not work on 486
276 architectures. Similarly, multiprocessor kernels for the "PPro"
277 architecture may not work on all Pentium based boards.
279 People using multiprocessor machines who say Y here should also say
280 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
281 Management" code will be disabled if you say Y here.
283 See also <file:Documentation/x86/i386/IO-APIC.txt>,
284 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
285 <http://www.tldp.org/docs.html#howto>.
287 If you don't know what to do here, say N.
290 bool "Support x2apic"
291 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
293 This enables x2apic support on CPUs that have this feature.
295 This allows 32-bit apic IDs (so it can support very large systems),
296 and accesses the local apic via MSRs not via mmio.
298 If you don't know what to do here, say N.
301 bool "Enable MPS table" if ACPI
303 depends on X86_LOCAL_APIC
305 For old smp systems that do not have proper acpi support. Newer systems
306 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
309 bool "Support for big SMP systems with more than 8 CPUs"
310 depends on X86_32 && SMP
312 This option is needed for the systems that have more than 8 CPUs
315 config X86_EXTENDED_PLATFORM
316 bool "Support for extended (non-PC) x86 platforms"
319 If you disable this option then the kernel will only support
320 standard PC platforms. (which covers the vast majority of
323 If you enable this option then you'll be able to select support
324 for the following (non-PC) 32 bit x86 platforms:
328 SGI 320/540 (Visual Workstation)
329 Summit/EXA (IBM x440)
330 Unisys ES7000 IA32 series
331 Moorestown MID devices
333 If you have one of these systems, or if you want to build a
334 generic distribution kernel, say Y here - otherwise say N.
338 config X86_EXTENDED_PLATFORM
339 bool "Support for extended (non-PC) x86 platforms"
342 If you disable this option then the kernel will only support
343 standard PC platforms. (which covers the vast majority of
346 If you enable this option then you'll be able to select support
347 for the following (non-PC) 64 bit x86 platforms:
351 If you have one of these systems, or if you want to build a
352 generic distribution kernel, say Y here - otherwise say N.
354 # This is an alphabetically sorted list of 64 bit extended platforms
355 # Please maintain the alphabetic order if and when there are additions
359 select PARAVIRT_GUEST
361 depends on X86_64 && PCI
362 depends on X86_EXTENDED_PLATFORM
364 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
365 supposed to run on these EM64T-based machines. Only choose this option
366 if you have one of these machines.
369 bool "SGI Ultraviolet"
371 depends on X86_EXTENDED_PLATFORM
373 depends on X86_X2APIC
375 This option is needed in order to support SGI Ultraviolet systems.
376 If you don't have one of these, you should say N here.
378 # Following is an alphabetically sorted list of 32 bit extended platforms
379 # Please maintain the alphabetic order if and when there are additions
382 bool "CE4100 TV platform"
384 depends on PCI_GODIRECT
386 depends on X86_EXTENDED_PLATFORM
387 select X86_REBOOTFIXUPS
389 select OF_EARLY_FLATTREE
391 Select for the Intel CE media processor (CE4100) SOC.
392 This option compiles in support for the CE4100 SOC for settop
393 boxes and media devices.
395 config X86_WANT_INTEL_MID
396 bool "Intel MID platform support"
398 depends on X86_EXTENDED_PLATFORM
400 Select to build a kernel capable of supporting Intel MID platform
401 systems which do not have the PCI legacy interfaces (Moorestown,
402 Medfield). If you are building for a PC class system say N here.
404 if X86_WANT_INTEL_MID
410 bool "Moorestown MID platform"
413 depends on X86_IO_APIC
418 select X86_PLATFORM_DEVICES
421 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
422 Internet Device(MID) platform. Moorestown consists of two chips:
423 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
424 Unlike standard x86 PCs, Moorestown does not have many legacy devices
425 nor standard legacy replacement devices/features. e.g. Moorestown does
426 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
431 bool "RDC R-321x SoC"
433 depends on X86_EXTENDED_PLATFORM
435 select X86_REBOOTFIXUPS
437 This option is needed for RDC R-321x system-on-chip, also known
439 If you don't have one of these chips, you should say N here.
441 config X86_32_NON_STANDARD
442 bool "Support non-standard 32-bit SMP architectures"
443 depends on X86_32 && SMP
444 depends on X86_EXTENDED_PLATFORM
446 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
447 subarchitectures. It is intended for a generic binary kernel.
448 if you select them all, kernel will probe it one by one. and will
451 # Alphabetically sorted list of Non standard 32 bit platforms
454 bool "NUMAQ (IBM/Sequent)"
455 depends on X86_32_NON_STANDARD
460 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
461 NUMA multiquad box. This changes the way that processors are
462 bootstrapped, and uses Clustered Logical APIC addressing mode instead
463 of Flat Logical. You will need a new lynxer.elf file to flash your
464 firmware with - send email to <Martin.Bligh@us.ibm.com>.
466 config X86_SUPPORTS_MEMORY_FAILURE
468 # MCE code calls memory_failure():
470 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
471 depends on !X86_NUMAQ
472 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
473 depends on X86_64 || !SPARSEMEM
474 select ARCH_SUPPORTS_MEMORY_FAILURE
477 bool "SGI 320/540 (Visual Workstation)"
478 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
479 depends on X86_32_NON_STANDARD
481 The SGI Visual Workstation series is an IA32-based workstation
482 based on SGI systems chips with some legacy PC hardware attached.
484 Say Y here to create a kernel to run on the SGI 320 or 540.
486 A kernel compiled for the Visual Workstation will run on general
487 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
490 bool "Summit/EXA (IBM x440)"
491 depends on X86_32_NON_STANDARD
493 This option is needed for IBM systems that use the Summit/EXA chipset.
494 In particular, it is needed for the x440.
497 bool "Unisys ES7000 IA32 series"
498 depends on X86_32_NON_STANDARD && X86_BIGSMP
500 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
501 supposed to run on an IA32-based Unisys ES7000 system.
504 tristate "Eurobraille/Iris poweroff module"
507 The Iris machines from EuroBraille do not have APM or ACPI support
508 to shut themselves down properly. A special I/O sequence is
509 needed to do so, which is what this module does at
512 This is only for Iris machines from EuroBraille.
516 config SCHED_OMIT_FRAME_POINTER
518 prompt "Single-depth WCHAN output"
521 Calculate simpler /proc/<PID>/wchan values. If this option
522 is disabled then wchan values will recurse back to the
523 caller function. This provides more accurate wchan values,
524 at the expense of slightly more scheduling overhead.
526 If in doubt, say "Y".
528 menuconfig PARAVIRT_GUEST
529 bool "Paravirtualized guest support"
531 Say Y here to get to see options related to running Linux under
532 various hypervisors. This option alone does not add any kernel code.
534 If you say N, all options in this submenu will be skipped and disabled.
538 config PARAVIRT_TIME_ACCOUNTING
539 bool "Paravirtual steal time accounting"
543 Select this option to enable fine granularity task steal time
544 accounting. Time spent executing other tasks in parallel with
545 the current vCPU is discounted from the vCPU power. To account for
546 that, there can be a small performance impact.
548 If in doubt, say N here.
550 source "arch/x86/xen/Kconfig"
553 bool "KVM paravirtualized clock"
555 select PARAVIRT_CLOCK
557 Turning on this option will allow you to run a paravirtualized clock
558 when running over the KVM hypervisor. Instead of relying on a PIT
559 (or probably other) emulation by the underlying device model, the host
560 provides the guest with timing infrastructure such as time of day, and
564 bool "KVM Guest support"
567 This option enables various optimizations for running under the KVM
570 source "arch/x86/lguest/Kconfig"
573 bool "Enable paravirtualization code"
575 This changes the kernel so it can modify itself when it is run
576 under a hypervisor, potentially improving performance significantly
577 over full virtualization. However, when run without a hypervisor
578 the kernel is theoretically slower and slightly larger.
580 config PARAVIRT_SPINLOCKS
581 bool "Paravirtualization layer for spinlocks"
582 depends on PARAVIRT && SMP && EXPERIMENTAL
584 Paravirtualized spinlocks allow a pvops backend to replace the
585 spinlock implementation with something virtualization-friendly
586 (for example, block the virtual CPU rather than spinning).
588 Unfortunately the downside is an up to 5% performance hit on
589 native kernels, with various workloads.
591 If you are unsure how to answer this question, answer N.
593 config PARAVIRT_CLOCK
598 config PARAVIRT_DEBUG
599 bool "paravirt-ops debugging"
600 depends on PARAVIRT && DEBUG_KERNEL
602 Enable to debug paravirt_ops internals. Specifically, BUG if
603 a paravirt_op is missing when it is called.
611 This option adds a kernel parameter 'memtest', which allows memtest
613 memtest=0, mean disabled; -- default
614 memtest=1, mean do 1 test pattern;
616 memtest=4, mean do 4 test patterns.
617 If you are unsure how to answer this question, answer N.
619 config X86_SUMMIT_NUMA
621 depends on X86_32 && NUMA && X86_32_NON_STANDARD
623 config X86_CYCLONE_TIMER
625 depends on X86_32_NON_STANDARD
627 source "arch/x86/Kconfig.cpu"
631 prompt "HPET Timer Support" if X86_32
633 Use the IA-PC HPET (High Precision Event Timer) to manage
634 time in preference to the PIT and RTC, if a HPET is
636 HPET is the next generation timer replacing legacy 8254s.
637 The HPET provides a stable time base on SMP
638 systems, unlike the TSC, but it is more expensive to access,
639 as it is off-chip. You can find the HPET spec at
640 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
642 You can safely choose Y here. However, HPET will only be
643 activated if the platform and the BIOS support this feature.
644 Otherwise the 8254 will be used for timing services.
646 Choose N to continue using the legacy 8254 timer.
648 config HPET_EMULATE_RTC
650 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
654 prompt "Langwell APB Timer Support" if X86_MRST
657 APB timer is the replacement for 8254, HPET on X86 MID platforms.
658 The APBT provides a stable time base on SMP
659 systems, unlike the TSC, but it is more expensive to access,
660 as it is off-chip. APB timers are always running regardless of CPU
661 C states, they are used as per CPU clockevent device when possible.
663 # Mark as expert because too many people got it wrong.
664 # The code disables itself when not needed.
667 bool "Enable DMI scanning" if EXPERT
669 Enabled scanning of DMI to identify machine quirks. Say Y
670 here unless you have verified that your setup is not
671 affected by entries in the DMI blacklist. Required by PNP
675 bool "GART IOMMU support" if EXPERT
678 depends on X86_64 && PCI && AMD_NB
680 Support for full DMA access of devices with 32bit memory access only
681 on systems with more than 3GB. This is usually needed for USB,
682 sound, many IDE/SATA chipsets and some other devices.
683 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
684 based hardware IOMMU and a software bounce buffer based IOMMU used
685 on Intel systems and as fallback.
686 The code is only active when needed (enough memory and limited
687 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
691 bool "IBM Calgary IOMMU support"
693 depends on X86_64 && PCI && EXPERIMENTAL
695 Support for hardware IOMMUs in IBM's xSeries x366 and x460
696 systems. Needed to run systems with more than 3GB of memory
697 properly with 32-bit PCI devices that do not support DAC
698 (Double Address Cycle). Calgary also supports bus level
699 isolation, where all DMAs pass through the IOMMU. This
700 prevents them from going anywhere except their intended
701 destination. This catches hard-to-find kernel bugs and
702 mis-behaving drivers and devices that do not use the DMA-API
703 properly to set up their DMA buffers. The IOMMU can be
704 turned off at boot time with the iommu=off parameter.
705 Normally the kernel will make the right choice by itself.
708 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
710 prompt "Should Calgary be enabled by default?"
711 depends on CALGARY_IOMMU
713 Should Calgary be enabled by default? if you choose 'y', Calgary
714 will be used (if it exists). If you choose 'n', Calgary will not be
715 used even if it exists. If you choose 'n' and would like to use
716 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
719 # need this always selected by IOMMU for the VIA workaround
723 Support for software bounce buffers used on x86-64 systems
724 which don't have a hardware IOMMU (e.g. the current generation
725 of Intel's x86-64 CPUs). Using this PCI devices which can only
726 access 32-bits of memory can be used on systems with more than
727 3 GB of memory. If unsure, say Y.
730 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
733 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
734 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
735 select CPUMASK_OFFSTACK
737 Enable maximum number of CPUS and NUMA Nodes for this architecture.
741 int "Maximum number of CPUs" if SMP && !MAXSMP
742 range 2 8 if SMP && X86_32 && !X86_BIGSMP
743 range 2 512 if SMP && !MAXSMP
745 default "4096" if MAXSMP
746 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
749 This allows you to specify the maximum number of CPUs which this
750 kernel will support. The maximum supported value is 512 and the
751 minimum value which makes sense is 2.
753 This is purely to save memory - each supported CPU adds
754 approximately eight kilobytes to the kernel image.
757 bool "SMT (Hyperthreading) scheduler support"
760 SMT scheduler support improves the CPU scheduler's decision making
761 when dealing with Intel Pentium 4 chips with HyperThreading at a
762 cost of slightly increased overhead in some places. If unsure say
767 prompt "Multi-core scheduler support"
770 Multi-core scheduler support improves the CPU scheduler's decision
771 making when dealing with multi-core CPU chips at a cost of slightly
772 increased overhead in some places. If unsure say N here.
774 config IRQ_TIME_ACCOUNTING
775 bool "Fine granularity task level IRQ time accounting"
778 Select this option to enable fine granularity task irq time
779 accounting. This is done by reading a timestamp on each
780 transitions between softirq and hardirq state, so there can be a
781 small performance impact.
783 If in doubt, say N here.
785 source "kernel/Kconfig.preempt"
788 bool "Local APIC support on uniprocessors"
789 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
791 A local APIC (Advanced Programmable Interrupt Controller) is an
792 integrated interrupt controller in the CPU. If you have a single-CPU
793 system which has a processor with a local APIC, you can say Y here to
794 enable and use it. If you say Y here even though your machine doesn't
795 have a local APIC, then the kernel will still run with no slowdown at
796 all. The local APIC supports CPU-generated self-interrupts (timer,
797 performance counters), and the NMI watchdog which detects hard
801 bool "IO-APIC support on uniprocessors"
802 depends on X86_UP_APIC
804 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
805 SMP-capable replacement for PC-style interrupt controllers. Most
806 SMP systems and many recent uniprocessor systems have one.
808 If you have a single-CPU system with an IO-APIC, you can say Y here
809 to use it. If you say Y here even though your machine doesn't have
810 an IO-APIC, then the kernel will still run with no slowdown at all.
812 config X86_LOCAL_APIC
814 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
818 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
820 config X86_VISWS_APIC
822 depends on X86_32 && X86_VISWS
824 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
825 bool "Reroute for broken boot IRQs"
826 depends on X86_IO_APIC
828 This option enables a workaround that fixes a source of
829 spurious interrupts. This is recommended when threaded
830 interrupt handling is used on systems where the generation of
831 superfluous "boot interrupts" cannot be disabled.
833 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
834 entry in the chipset's IO-APIC is masked (as, e.g. the RT
835 kernel does during interrupt handling). On chipsets where this
836 boot IRQ generation cannot be disabled, this workaround keeps
837 the original IRQ line masked so that only the equivalent "boot
838 IRQ" is delivered to the CPUs. The workaround also tells the
839 kernel to set up the IRQ handler on the boot IRQ line. In this
840 way only one interrupt is delivered to the kernel. Otherwise
841 the spurious second interrupt may cause the kernel to bring
842 down (vital) interrupt lines.
844 Only affects "broken" chipsets. Interrupt sharing may be
845 increased on these systems.
848 bool "Machine Check / overheating reporting"
850 Machine Check support allows the processor to notify the
851 kernel if it detects a problem (e.g. overheating, data corruption).
852 The action the kernel takes depends on the severity of the problem,
853 ranging from warning messages to halting the machine.
857 prompt "Intel MCE features"
858 depends on X86_MCE && X86_LOCAL_APIC
860 Additional support for intel specific MCE features such as
865 prompt "AMD MCE features"
866 depends on X86_MCE && X86_LOCAL_APIC
868 Additional support for AMD specific MCE features such as
869 the DRAM Error Threshold.
871 config X86_ANCIENT_MCE
872 bool "Support for old Pentium 5 / WinChip machine checks"
873 depends on X86_32 && X86_MCE
875 Include support for machine check handling on old Pentium 5 or WinChip
876 systems. These typically need to be enabled explicitely on the command
879 config X86_MCE_THRESHOLD
880 depends on X86_MCE_AMD || X86_MCE_INTEL
883 config X86_MCE_INJECT
885 tristate "Machine check injector support"
887 Provide support for injecting machine checks for testing purposes.
888 If you don't know what a machine check is and you don't do kernel
889 QA it is safe to say n.
891 config X86_THERMAL_VECTOR
893 depends on X86_MCE_INTEL
896 bool "Enable VM86 support" if EXPERT
900 This option is required by programs like DOSEMU to run
901 16-bit real mode legacy code on x86 processors. It also may
902 be needed by software like XFree86 to initialize some video
903 cards via BIOS. Disabling this option saves about 6K.
906 bool "Enable support for 16-bit segments" if EXPERT
909 This option is required by programs like Wine to run 16-bit
910 protected mode legacy code on x86 processors. Disabling
911 this option saves about 300 bytes on i386, or around 6K text
912 plus 16K runtime memory on x86-64,
916 depends on X86_16BIT && X86_32
920 depends on X86_16BIT && X86_64
923 tristate "Toshiba Laptop support"
926 This adds a driver to safely access the System Management Mode of
927 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
928 not work on models with a Phoenix BIOS. The System Management Mode
929 is used to set the BIOS and power saving options on Toshiba portables.
931 For information on utilities to make use of this driver see the
932 Toshiba Linux utilities web site at:
933 <http://www.buzzard.org.uk/toshiba/>.
935 Say Y if you intend to run this kernel on a Toshiba portable.
939 tristate "Dell laptop support"
942 This adds a driver to safely access the System Management Mode
943 of the CPU on the Dell Inspiron 8000. The System Management Mode
944 is used to read cpu temperature and cooling fan status and to
945 control the fans on the I8K portables.
947 This driver has been tested only on the Inspiron 8000 but it may
948 also work with other Dell laptops. You can force loading on other
949 models by passing the parameter `force=1' to the module. Use at
952 For information on utilities to make use of this driver see the
953 I8K Linux utilities web site at:
954 <http://people.debian.org/~dz/i8k/>
956 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
959 config X86_REBOOTFIXUPS
960 bool "Enable X86 board specific fixups for reboot"
963 This enables chipset and/or board specific fixups to be done
964 in order to get reboot to work correctly. This is only needed on
965 some combinations of hardware and BIOS. The symptom, for which
966 this config is intended, is when reboot ends with a stalled/hung
969 Currently, the only fixup is for the Geode machines using
970 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
972 Say Y if you want to enable the fixup. Currently, it's safe to
973 enable this option even if you don't need it.
977 tristate "/dev/cpu/microcode - microcode support"
980 If you say Y here, you will be able to update the microcode on
981 certain Intel and AMD processors. The Intel support is for the
982 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
983 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
984 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
985 You will obviously need the actual microcode binary data itself
986 which is not shipped with the Linux kernel.
988 This option selects the general module only, you need to select
989 at least one vendor specific module as well.
991 To compile this driver as a module, choose M here: the
992 module will be called microcode.
994 config MICROCODE_INTEL
995 bool "Intel microcode patch loading support"
1000 This options enables microcode patch loading support for Intel
1003 For latest news and information on obtaining all the required
1004 Intel ingredients for this driver, check:
1005 <http://www.urbanmyth.org/microcode/>.
1007 config MICROCODE_AMD
1008 bool "AMD microcode patch loading support"
1009 depends on MICROCODE
1012 If you select this option, microcode patch loading support for AMD
1013 processors will be enabled.
1015 config MICROCODE_OLD_INTERFACE
1017 depends on MICROCODE
1020 tristate "/dev/cpu/*/msr - Model-specific register support"
1022 This device gives privileged processes access to the x86
1023 Model-Specific Registers (MSRs). It is a character device with
1024 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1025 MSR accesses are directed to a specific CPU on multi-processor
1029 tristate "/dev/cpu/*/cpuid - CPU information support"
1031 This device gives processes access to the x86 CPUID instruction to
1032 be executed on a specific processor. It is a character device
1033 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1037 prompt "High Memory Support"
1038 default HIGHMEM64G if X86_NUMAQ
1044 depends on !X86_NUMAQ
1046 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1047 However, the address space of 32-bit x86 processors is only 4
1048 Gigabytes large. That means that, if you have a large amount of
1049 physical memory, not all of it can be "permanently mapped" by the
1050 kernel. The physical memory that's not permanently mapped is called
1053 If you are compiling a kernel which will never run on a machine with
1054 more than 1 Gigabyte total physical RAM, answer "off" here (default
1055 choice and suitable for most users). This will result in a "3GB/1GB"
1056 split: 3GB are mapped so that each process sees a 3GB virtual memory
1057 space and the remaining part of the 4GB virtual memory space is used
1058 by the kernel to permanently map as much physical memory as
1061 If the machine has between 1 and 4 Gigabytes physical RAM, then
1064 If more than 4 Gigabytes is used then answer "64GB" here. This
1065 selection turns Intel PAE (Physical Address Extension) mode on.
1066 PAE implements 3-level paging on IA32 processors. PAE is fully
1067 supported by Linux, PAE mode is implemented on all recent Intel
1068 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1069 then the kernel will not boot on CPUs that don't support PAE!
1071 The actual amount of total physical memory will either be
1072 auto detected or can be forced by using a kernel command line option
1073 such as "mem=256M". (Try "man bootparam" or see the documentation of
1074 your boot loader (lilo or loadlin) about how to pass options to the
1075 kernel at boot time.)
1077 If unsure, say "off".
1081 depends on !X86_NUMAQ
1083 Select this if you have a 32-bit processor and between 1 and 4
1084 gigabytes of physical RAM.
1088 depends on !M386 && !M486
1091 Select this if you have a 32-bit processor and more than 4
1092 gigabytes of physical RAM.
1097 depends on EXPERIMENTAL
1098 prompt "Memory split" if EXPERT
1102 Select the desired split between kernel and user memory.
1104 If the address range available to the kernel is less than the
1105 physical memory installed, the remaining memory will be available
1106 as "high memory". Accessing high memory is a little more costly
1107 than low memory, as it needs to be mapped into the kernel first.
1108 Note that increasing the kernel address space limits the range
1109 available to user programs, making the address space there
1110 tighter. Selecting anything other than the default 3G/1G split
1111 will also likely make your kernel incompatible with binary-only
1114 If you are not absolutely sure what you are doing, leave this
1118 bool "3G/1G user/kernel split"
1119 config VMSPLIT_3G_OPT
1121 bool "3G/1G user/kernel split (for full 1G low memory)"
1123 bool "2G/2G user/kernel split"
1124 config VMSPLIT_2G_OPT
1126 bool "2G/2G user/kernel split (for full 2G low memory)"
1128 bool "1G/3G user/kernel split"
1133 default 0xB0000000 if VMSPLIT_3G_OPT
1134 default 0x80000000 if VMSPLIT_2G
1135 default 0x78000000 if VMSPLIT_2G_OPT
1136 default 0x40000000 if VMSPLIT_1G
1142 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1145 bool "PAE (Physical Address Extension) Support"
1146 depends on X86_32 && !HIGHMEM4G
1148 PAE is required for NX support, and furthermore enables
1149 larger swapspace support for non-overcommit purposes. It
1150 has the cost of more pagetable lookup overhead, and also
1151 consumes more pagetable space per process.
1153 config ARCH_PHYS_ADDR_T_64BIT
1154 def_bool X86_64 || X86_PAE
1156 config ARCH_DMA_ADDR_T_64BIT
1157 def_bool X86_64 || HIGHMEM64G
1159 config DIRECT_GBPAGES
1160 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1164 Allow the kernel linear mapping to use 1GB pages on CPUs that
1165 support it. This can improve the kernel's performance a tiny bit by
1166 reducing TLB pressure. If in doubt, say "Y".
1168 # Common NUMA Features
1170 bool "Numa Memory Allocation and Scheduler Support"
1172 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && BROKEN)
1173 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1175 Enable NUMA (Non Uniform Memory Access) support.
1177 The kernel will try to allocate memory used by a CPU on the
1178 local memory controller of the CPU and add some more
1179 NUMA awareness to the kernel.
1181 For 64-bit this is recommended if the system is Intel Core i7
1182 (or later), AMD Opteron, or EM64T NUMA.
1184 For 32-bit this is only needed on (rare) 32-bit-only platforms
1185 that support NUMA topologies, such as NUMAQ / Summit, or if you
1186 boot a 32-bit kernel on a 64-bit NUMA platform.
1188 Otherwise, you should say N.
1190 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1191 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1195 prompt "Old style AMD Opteron NUMA detection"
1196 depends on X86_64 && NUMA && PCI
1198 Enable AMD NUMA node topology detection. You should say Y here if
1199 you have a multi processor AMD system. This uses an old method to
1200 read the NUMA configuration directly from the builtin Northbridge
1201 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1202 which also takes priority if both are compiled in.
1204 config X86_64_ACPI_NUMA
1206 prompt "ACPI NUMA detection"
1207 depends on X86_64 && NUMA && ACPI && PCI
1210 Enable ACPI SRAT based node topology detection.
1212 # Some NUMA nodes have memory ranges that span
1213 # other nodes. Even though a pfn is valid and
1214 # between a node's start and end pfns, it may not
1215 # reside on that node. See memmap_init_zone()
1217 config NODES_SPAN_OTHER_NODES
1219 depends on X86_64_ACPI_NUMA
1222 bool "NUMA emulation"
1225 Enable NUMA emulation. A flat machine will be split
1226 into virtual nodes when booted with "numa=fake=N", where N is the
1227 number of nodes. This is only useful for debugging.
1230 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1232 default "10" if MAXSMP
1233 default "6" if X86_64
1234 default "4" if X86_NUMAQ
1236 depends on NEED_MULTIPLE_NODES
1238 Specify the maximum number of NUMA Nodes available on the target
1239 system. Increases memory reserved to accommodate various tables.
1241 config HAVE_ARCH_BOOTMEM
1243 depends on X86_32 && NUMA
1245 config HAVE_ARCH_ALLOC_REMAP
1247 depends on X86_32 && NUMA
1249 config ARCH_HAVE_MEMORY_PRESENT
1251 depends on X86_32 && DISCONTIGMEM
1253 config NEED_NODE_MEMMAP_SIZE
1255 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1257 config ARCH_FLATMEM_ENABLE
1259 depends on X86_32 && !NUMA
1261 config ARCH_DISCONTIGMEM_ENABLE
1263 depends on NUMA && X86_32
1265 config ARCH_DISCONTIGMEM_DEFAULT
1267 depends on NUMA && X86_32
1269 config ARCH_SPARSEMEM_ENABLE
1271 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1272 select SPARSEMEM_STATIC if X86_32
1273 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1275 config ARCH_SPARSEMEM_DEFAULT
1279 config ARCH_SELECT_MEMORY_MODEL
1281 depends on ARCH_SPARSEMEM_ENABLE
1283 config ARCH_MEMORY_PROBE
1285 depends on MEMORY_HOTPLUG
1287 config ARCH_PROC_KCORE_TEXT
1289 depends on X86_64 && PROC_KCORE
1291 config ILLEGAL_POINTER_VALUE
1294 default 0xdead000000000000 if X86_64
1299 bool "Allocate 3rd-level pagetables from highmem"
1302 The VM uses one page table entry for each page of physical memory.
1303 For systems with a lot of RAM, this can be wasteful of precious
1304 low memory. Setting this option will put user-space page table
1305 entries in high memory.
1307 config X86_CHECK_BIOS_CORRUPTION
1308 bool "Check for low memory corruption"
1310 Periodically check for memory corruption in low memory, which
1311 is suspected to be caused by BIOS. Even when enabled in the
1312 configuration, it is disabled at runtime. Enable it by
1313 setting "memory_corruption_check=1" on the kernel command
1314 line. By default it scans the low 64k of memory every 60
1315 seconds; see the memory_corruption_check_size and
1316 memory_corruption_check_period parameters in
1317 Documentation/kernel-parameters.txt to adjust this.
1319 When enabled with the default parameters, this option has
1320 almost no overhead, as it reserves a relatively small amount
1321 of memory and scans it infrequently. It both detects corruption
1322 and prevents it from affecting the running system.
1324 It is, however, intended as a diagnostic tool; if repeatable
1325 BIOS-originated corruption always affects the same memory,
1326 you can use memmap= to prevent the kernel from using that
1329 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1330 bool "Set the default setting of memory_corruption_check"
1331 depends on X86_CHECK_BIOS_CORRUPTION
1334 Set whether the default state of memory_corruption_check is
1337 config X86_RESERVE_LOW
1338 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1342 Specify the amount of low memory to reserve for the BIOS.
1344 The first page contains BIOS data structures that the kernel
1345 must not use, so that page must always be reserved.
1347 By default we reserve the first 64K of physical RAM, as a
1348 number of BIOSes are known to corrupt that memory range
1349 during events such as suspend/resume or monitor cable
1350 insertion, so it must not be used by the kernel.
1352 You can set this to 4 if you are absolutely sure that you
1353 trust the BIOS to get all its memory reservations and usages
1354 right. If you know your BIOS have problems beyond the
1355 default 64K area, you can set this to 640 to avoid using the
1356 entire low memory range.
1358 If you have doubts about the BIOS (e.g. suspend/resume does
1359 not work or there's kernel crashes after certain hardware
1360 hotplug events) then you might want to enable
1361 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1362 typical corruption patterns.
1364 Leave this to the default value of 64 if you are unsure.
1366 config MATH_EMULATION
1368 prompt "Math emulation" if X86_32
1370 Linux can emulate a math coprocessor (used for floating point
1371 operations) if you don't have one. 486DX and Pentium processors have
1372 a math coprocessor built in, 486SX and 386 do not, unless you added
1373 a 487DX or 387, respectively. (The messages during boot time can
1374 give you some hints here ["man dmesg"].) Everyone needs either a
1375 coprocessor or this emulation.
1377 If you don't have a math coprocessor, you need to say Y here; if you
1378 say Y here even though you have a coprocessor, the coprocessor will
1379 be used nevertheless. (This behavior can be changed with the kernel
1380 command line option "no387", which comes handy if your coprocessor
1381 is broken. Try "man bootparam" or see the documentation of your boot
1382 loader (lilo or loadlin) about how to pass options to the kernel at
1383 boot time.) This means that it is a good idea to say Y here if you
1384 intend to use this kernel on different machines.
1386 More information about the internals of the Linux math coprocessor
1387 emulation can be found in <file:arch/x86/math-emu/README>.
1389 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1390 kernel, it won't hurt.
1394 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1396 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1397 the Memory Type Range Registers (MTRRs) may be used to control
1398 processor access to memory ranges. This is most useful if you have
1399 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1400 allows bus write transfers to be combined into a larger transfer
1401 before bursting over the PCI/AGP bus. This can increase performance
1402 of image write operations 2.5 times or more. Saying Y here creates a
1403 /proc/mtrr file which may be used to manipulate your processor's
1404 MTRRs. Typically the X server should use this.
1406 This code has a reasonably generic interface so that similar
1407 control registers on other processors can be easily supported
1410 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1411 Registers (ARRs) which provide a similar functionality to MTRRs. For
1412 these, the ARRs are used to emulate the MTRRs.
1413 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1414 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1415 write-combining. All of these processors are supported by this code
1416 and it makes sense to say Y here if you have one of them.
1418 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1419 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1420 can lead to all sorts of problems, so it's good to say Y here.
1422 You can safely say Y even if your machine doesn't have MTRRs, you'll
1423 just add about 9 KB to your kernel.
1425 See <file:Documentation/x86/mtrr.txt> for more information.
1427 config MTRR_SANITIZER
1429 prompt "MTRR cleanup support"
1432 Convert MTRR layout from continuous to discrete, so X drivers can
1433 add writeback entries.
1435 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1436 The largest mtrr entry size for a continuous block can be set with
1441 config MTRR_SANITIZER_ENABLE_DEFAULT
1442 int "MTRR cleanup enable value (0-1)"
1445 depends on MTRR_SANITIZER
1447 Enable mtrr cleanup default value
1449 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1450 int "MTRR cleanup spare reg num (0-7)"
1453 depends on MTRR_SANITIZER
1455 mtrr cleanup spare entries default, it can be changed via
1456 mtrr_spare_reg_nr=N on the kernel command line.
1460 prompt "x86 PAT support" if EXPERT
1463 Use PAT attributes to setup page level cache control.
1465 PATs are the modern equivalents of MTRRs and are much more
1466 flexible than MTRRs.
1468 Say N here if you see bootup problems (boot crash, boot hang,
1469 spontaneous reboots) or a non-working video driver.
1473 config ARCH_USES_PG_UNCACHED
1479 prompt "x86 architectural random number generator" if EXPERT
1481 Enable the x86 architectural RDRAND instruction
1482 (Intel Bull Mountain technology) to generate random numbers.
1483 If supported, this is a high bandwidth, cryptographically
1484 secure hardware random number generator.
1487 bool "EFI runtime service support"
1490 This enables the kernel to use EFI runtime services that are
1491 available (such as the EFI variable services).
1493 This option is only useful on systems that have EFI firmware.
1494 In addition, you should use the latest ELILO loader available
1495 at <http://elilo.sourceforge.net> in order to take advantage
1496 of EFI runtime services. However, even with this option, the
1497 resultant kernel should continue to boot on existing non-EFI
1502 prompt "Enable seccomp to safely compute untrusted bytecode"
1504 This kernel feature is useful for number crunching applications
1505 that may need to compute untrusted bytecode during their
1506 execution. By using pipes or other transports made available to
1507 the process as file descriptors supporting the read/write
1508 syscalls, it's possible to isolate those applications in
1509 their own address space using seccomp. Once seccomp is
1510 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1511 and the task is only allowed to execute a few safe syscalls
1512 defined by each seccomp mode.
1514 If unsure, say Y. Only embedded should say N here.
1516 config CC_STACKPROTECTOR
1517 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1519 This option turns on the -fstack-protector GCC feature. This
1520 feature puts, at the beginning of functions, a canary value on
1521 the stack just before the return address, and validates
1522 the value just before actually returning. Stack based buffer
1523 overflows (that need to overwrite this return address) now also
1524 overwrite the canary, which gets detected and the attack is then
1525 neutralized via a kernel panic.
1527 This feature requires gcc version 4.2 or above, or a distribution
1528 gcc with the feature backported. Older versions are automatically
1529 detected and for those versions, this configuration option is
1530 ignored. (and a warning is printed during bootup)
1532 source kernel/Kconfig.hz
1535 bool "kexec system call"
1537 kexec is a system call that implements the ability to shutdown your
1538 current kernel, and to start another kernel. It is like a reboot
1539 but it is independent of the system firmware. And like a reboot
1540 you can start any kernel with it, not just Linux.
1542 The name comes from the similarity to the exec system call.
1544 It is an ongoing process to be certain the hardware in a machine
1545 is properly shutdown, so do not be surprised if this code does not
1546 initially work for you. It may help to enable device hotplugging
1547 support. As of this writing the exact hardware interface is
1548 strongly in flux, so no good recommendation can be made.
1551 bool "kernel crash dumps"
1552 depends on X86_64 || (X86_32 && HIGHMEM)
1554 Generate crash dump after being started by kexec.
1555 This should be normally only set in special crash dump kernels
1556 which are loaded in the main kernel with kexec-tools into
1557 a specially reserved region and then later executed after
1558 a crash by kdump/kexec. The crash dump kernel must be compiled
1559 to a memory address not used by the main kernel or BIOS using
1560 PHYSICAL_START, or it must be built as a relocatable image
1561 (CONFIG_RELOCATABLE=y).
1562 For more details see Documentation/kdump/kdump.txt
1565 bool "kexec jump (EXPERIMENTAL)"
1566 depends on EXPERIMENTAL
1567 depends on KEXEC && HIBERNATION
1569 Jump between original kernel and kexeced kernel and invoke
1570 code in physical address mode via KEXEC
1572 config PHYSICAL_START
1573 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1576 This gives the physical address where the kernel is loaded.
1578 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1579 bzImage will decompress itself to above physical address and
1580 run from there. Otherwise, bzImage will run from the address where
1581 it has been loaded by the boot loader and will ignore above physical
1584 In normal kdump cases one does not have to set/change this option
1585 as now bzImage can be compiled as a completely relocatable image
1586 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1587 address. This option is mainly useful for the folks who don't want
1588 to use a bzImage for capturing the crash dump and want to use a
1589 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1590 to be specifically compiled to run from a specific memory area
1591 (normally a reserved region) and this option comes handy.
1593 So if you are using bzImage for capturing the crash dump,
1594 leave the value here unchanged to 0x1000000 and set
1595 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1596 for capturing the crash dump change this value to start of
1597 the reserved region. In other words, it can be set based on
1598 the "X" value as specified in the "crashkernel=YM@XM"
1599 command line boot parameter passed to the panic-ed
1600 kernel. Please take a look at Documentation/kdump/kdump.txt
1601 for more details about crash dumps.
1603 Usage of bzImage for capturing the crash dump is recommended as
1604 one does not have to build two kernels. Same kernel can be used
1605 as production kernel and capture kernel. Above option should have
1606 gone away after relocatable bzImage support is introduced. But it
1607 is present because there are users out there who continue to use
1608 vmlinux for dump capture. This option should go away down the
1611 Don't change this unless you know what you are doing.
1614 bool "Build a relocatable kernel"
1617 This builds a kernel image that retains relocation information
1618 so it can be loaded someplace besides the default 1MB.
1619 The relocations tend to make the kernel binary about 10% larger,
1620 but are discarded at runtime.
1622 One use is for the kexec on panic case where the recovery kernel
1623 must live at a different physical address than the primary
1626 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1627 it has been loaded at and the compile time physical address
1628 (CONFIG_PHYSICAL_START) is ignored.
1630 # Relocation on x86-32 needs some additional build support
1631 config X86_NEED_RELOCS
1633 depends on X86_32 && RELOCATABLE
1635 config PHYSICAL_ALIGN
1636 hex "Alignment value to which kernel should be aligned" if X86_32
1638 range 0x2000 0x1000000
1640 This value puts the alignment restrictions on physical address
1641 where kernel is loaded and run from. Kernel is compiled for an
1642 address which meets above alignment restriction.
1644 If bootloader loads the kernel at a non-aligned address and
1645 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1646 address aligned to above value and run from there.
1648 If bootloader loads the kernel at a non-aligned address and
1649 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1650 load address and decompress itself to the address it has been
1651 compiled for and run from there. The address for which kernel is
1652 compiled already meets above alignment restrictions. Hence the
1653 end result is that kernel runs from a physical address meeting
1654 above alignment restrictions.
1656 Don't change this unless you know what you are doing.
1659 bool "Support for hot-pluggable CPUs"
1660 depends on SMP && HOTPLUG
1662 Say Y here to allow turning CPUs off and on. CPUs can be
1663 controlled through /sys/devices/system/cpu.
1664 ( Note: power management support will enable this option
1665 automatically on SMP systems. )
1666 Say N if you want to disable CPU hotplug.
1670 prompt "Compat VDSO support"
1671 depends on X86_32 || IA32_EMULATION
1673 Map the 32-bit VDSO to the predictable old-style address too.
1675 Say N here if you are running a sufficiently recent glibc
1676 version (2.3.3 or later), to remove the high-mapped
1677 VDSO mapping and to exclusively use the randomized VDSO.
1682 bool "Built-in kernel command line"
1684 Allow for specifying boot arguments to the kernel at
1685 build time. On some systems (e.g. embedded ones), it is
1686 necessary or convenient to provide some or all of the
1687 kernel boot arguments with the kernel itself (that is,
1688 to not rely on the boot loader to provide them.)
1690 To compile command line arguments into the kernel,
1691 set this option to 'Y', then fill in the
1692 the boot arguments in CONFIG_CMDLINE.
1694 Systems with fully functional boot loaders (i.e. non-embedded)
1695 should leave this option set to 'N'.
1698 string "Built-in kernel command string"
1699 depends on CMDLINE_BOOL
1702 Enter arguments here that should be compiled into the kernel
1703 image and used at boot time. If the boot loader provides a
1704 command line at boot time, it is appended to this string to
1705 form the full kernel command line, when the system boots.
1707 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1708 change this behavior.
1710 In most cases, the command line (whether built-in or provided
1711 by the boot loader) should specify the device for the root
1714 config CMDLINE_OVERRIDE
1715 bool "Built-in command line overrides boot loader arguments"
1716 depends on CMDLINE_BOOL
1718 Set this option to 'Y' to have the kernel ignore the boot loader
1719 command line, and use ONLY the built-in command line.
1721 This is used to work around broken boot loaders. This should
1722 be set to 'N' under normal conditions.
1726 config ARCH_ENABLE_MEMORY_HOTPLUG
1728 depends on X86_64 || (X86_32 && HIGHMEM)
1730 config ARCH_ENABLE_MEMORY_HOTREMOVE
1732 depends on MEMORY_HOTPLUG
1734 config USE_PERCPU_NUMA_NODE_ID
1738 menu "Power management and ACPI options"
1740 config ARCH_HIBERNATION_HEADER
1742 depends on X86_64 && HIBERNATION
1744 source "kernel/power/Kconfig"
1746 source "drivers/acpi/Kconfig"
1748 source "drivers/sfi/Kconfig"
1752 depends on APM || APM_MODULE
1755 tristate "APM (Advanced Power Management) BIOS support"
1756 depends on X86_32 && PM_SLEEP
1758 APM is a BIOS specification for saving power using several different
1759 techniques. This is mostly useful for battery powered laptops with
1760 APM compliant BIOSes. If you say Y here, the system time will be
1761 reset after a RESUME operation, the /proc/apm device will provide
1762 battery status information, and user-space programs will receive
1763 notification of APM "events" (e.g. battery status change).
1765 If you select "Y" here, you can disable actual use of the APM
1766 BIOS by passing the "apm=off" option to the kernel at boot time.
1768 Note that the APM support is almost completely disabled for
1769 machines with more than one CPU.
1771 In order to use APM, you will need supporting software. For location
1772 and more information, read <file:Documentation/power/apm-acpi.txt>
1773 and the Battery Powered Linux mini-HOWTO, available from
1774 <http://www.tldp.org/docs.html#howto>.
1776 This driver does not spin down disk drives (see the hdparm(8)
1777 manpage ("man 8 hdparm") for that), and it doesn't turn off
1778 VESA-compliant "green" monitors.
1780 This driver does not support the TI 4000M TravelMate and the ACER
1781 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1782 desktop machines also don't have compliant BIOSes, and this driver
1783 may cause those machines to panic during the boot phase.
1785 Generally, if you don't have a battery in your machine, there isn't
1786 much point in using this driver and you should say N. If you get
1787 random kernel OOPSes or reboots that don't seem to be related to
1788 anything, try disabling/enabling this option (or disabling/enabling
1791 Some other things you should try when experiencing seemingly random,
1794 1) make sure that you have enough swap space and that it is
1796 2) pass the "no-hlt" option to the kernel
1797 3) switch on floating point emulation in the kernel and pass
1798 the "no387" option to the kernel
1799 4) pass the "floppy=nodma" option to the kernel
1800 5) pass the "mem=4M" option to the kernel (thereby disabling
1801 all but the first 4 MB of RAM)
1802 6) make sure that the CPU is not over clocked.
1803 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1804 8) disable the cache from your BIOS settings
1805 9) install a fan for the video card or exchange video RAM
1806 10) install a better fan for the CPU
1807 11) exchange RAM chips
1808 12) exchange the motherboard.
1810 To compile this driver as a module, choose M here: the
1811 module will be called apm.
1815 config APM_IGNORE_USER_SUSPEND
1816 bool "Ignore USER SUSPEND"
1818 This option will ignore USER SUSPEND requests. On machines with a
1819 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1820 series notebooks, it is necessary to say Y because of a BIOS bug.
1822 config APM_DO_ENABLE
1823 bool "Enable PM at boot time"
1825 Enable APM features at boot time. From page 36 of the APM BIOS
1826 specification: "When disabled, the APM BIOS does not automatically
1827 power manage devices, enter the Standby State, enter the Suspend
1828 State, or take power saving steps in response to CPU Idle calls."
1829 This driver will make CPU Idle calls when Linux is idle (unless this
1830 feature is turned off -- see "Do CPU IDLE calls", below). This
1831 should always save battery power, but more complicated APM features
1832 will be dependent on your BIOS implementation. You may need to turn
1833 this option off if your computer hangs at boot time when using APM
1834 support, or if it beeps continuously instead of suspending. Turn
1835 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1836 T400CDT. This is off by default since most machines do fine without
1840 bool "Make CPU Idle calls when idle"
1842 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1843 On some machines, this can activate improved power savings, such as
1844 a slowed CPU clock rate, when the machine is idle. These idle calls
1845 are made after the idle loop has run for some length of time (e.g.,
1846 333 mS). On some machines, this will cause a hang at boot time or
1847 whenever the CPU becomes idle. (On machines with more than one CPU,
1848 this option does nothing.)
1850 config APM_DISPLAY_BLANK
1851 bool "Enable console blanking using APM"
1853 Enable console blanking using the APM. Some laptops can use this to
1854 turn off the LCD backlight when the screen blanker of the Linux
1855 virtual console blanks the screen. Note that this is only used by
1856 the virtual console screen blanker, and won't turn off the backlight
1857 when using the X Window system. This also doesn't have anything to
1858 do with your VESA-compliant power-saving monitor. Further, this
1859 option doesn't work for all laptops -- it might not turn off your
1860 backlight at all, or it might print a lot of errors to the console,
1861 especially if you are using gpm.
1863 config APM_ALLOW_INTS
1864 bool "Allow interrupts during APM BIOS calls"
1866 Normally we disable external interrupts while we are making calls to
1867 the APM BIOS as a measure to lessen the effects of a badly behaving
1868 BIOS implementation. The BIOS should reenable interrupts if it
1869 needs to. Unfortunately, some BIOSes do not -- especially those in
1870 many of the newer IBM Thinkpads. If you experience hangs when you
1871 suspend, try setting this to Y. Otherwise, say N.
1875 source "drivers/cpufreq/Kconfig"
1877 source "drivers/cpuidle/Kconfig"
1879 source "drivers/idle/Kconfig"
1884 menu "Bus options (PCI etc.)"
1889 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1891 Find out whether you have a PCI motherboard. PCI is the name of a
1892 bus system, i.e. the way the CPU talks to the other stuff inside
1893 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1894 VESA. If you have PCI, say Y, otherwise N.
1897 prompt "PCI access mode"
1898 depends on X86_32 && PCI
1901 On PCI systems, the BIOS can be used to detect the PCI devices and
1902 determine their configuration. However, some old PCI motherboards
1903 have BIOS bugs and may crash if this is done. Also, some embedded
1904 PCI-based systems don't have any BIOS at all. Linux can also try to
1905 detect the PCI hardware directly without using the BIOS.
1907 With this option, you can specify how Linux should detect the
1908 PCI devices. If you choose "BIOS", the BIOS will be used,
1909 if you choose "Direct", the BIOS won't be used, and if you
1910 choose "MMConfig", then PCI Express MMCONFIG will be used.
1911 If you choose "Any", the kernel will try MMCONFIG, then the
1912 direct access method and falls back to the BIOS if that doesn't
1913 work. If unsure, go with the default, which is "Any".
1918 config PCI_GOMMCONFIG
1935 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1937 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1940 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1944 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1948 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1952 depends on PCI && XEN
1960 bool "Support mmconfig PCI config space access"
1961 depends on X86_64 && PCI && ACPI
1963 config PCI_CNB20LE_QUIRK
1964 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1966 depends on PCI && EXPERIMENTAL
1968 Read the PCI windows out of the CNB20LE host bridge. This allows
1969 PCI hotplug to work on systems with the CNB20LE chipset which do
1972 There's no public spec for this chipset, and this functionality
1973 is known to be incomplete.
1975 You should say N unless you know you need this.
1977 source "drivers/pci/pcie/Kconfig"
1979 source "drivers/pci/Kconfig"
1981 # x86_64 have no ISA slots, but can have ISA-style DMA.
1983 bool "ISA-style DMA support" if (X86_64 && EXPERT)
1986 Enables ISA-style DMA support for devices requiring such controllers.
1994 Find out whether you have ISA slots on your motherboard. ISA is the
1995 name of a bus system, i.e. the way the CPU talks to the other stuff
1996 inside your box. Other bus systems are PCI, EISA, MicroChannel
1997 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1998 newer boards don't support it. If you have ISA, say Y, otherwise N.
2004 The Extended Industry Standard Architecture (EISA) bus was
2005 developed as an open alternative to the IBM MicroChannel bus.
2007 The EISA bus provided some of the features of the IBM MicroChannel
2008 bus while maintaining backward compatibility with cards made for
2009 the older ISA bus. The EISA bus saw limited use between 1988 and
2010 1995 when it was made obsolete by the PCI bus.
2012 Say Y here if you are building a kernel for an EISA-based machine.
2016 source "drivers/eisa/Kconfig"
2021 MicroChannel Architecture is found in some IBM PS/2 machines and
2022 laptops. It is a bus system similar to PCI or ISA. See
2023 <file:Documentation/mca.txt> (and especially the web page given
2024 there) before attempting to build an MCA bus kernel.
2026 source "drivers/mca/Kconfig"
2029 tristate "NatSemi SCx200 support"
2031 This provides basic support for National Semiconductor's
2032 (now AMD's) Geode processors. The driver probes for the
2033 PCI-IDs of several on-chip devices, so its a good dependency
2034 for other scx200_* drivers.
2036 If compiled as a module, the driver is named scx200.
2038 config SCx200HR_TIMER
2039 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2043 This driver provides a clocksource built upon the on-chip
2044 27MHz high-resolution timer. Its also a workaround for
2045 NSC Geode SC-1100's buggy TSC, which loses time when the
2046 processor goes idle (as is done by the scheduler). The
2047 other workaround is idle=poll boot option.
2050 bool "One Laptop Per Child support"
2056 Add support for detecting the unique features of the OLPC
2060 bool "OLPC XO-1 Power Management"
2061 depends on OLPC && MFD_CS5535 && PM_SLEEP
2064 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2067 bool "OLPC XO-1 Real Time Clock"
2068 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2070 Add support for the XO-1 real time clock, which can be used as a
2071 programmable wakeup source.
2074 bool "OLPC XO-1 SCI extras"
2075 depends on OLPC && OLPC_XO1_PM
2080 Add support for SCI-based features of the OLPC XO-1 laptop:
2081 - EC-driven system wakeups
2085 - AC adapter status updates
2086 - Battery status updates
2088 config OLPC_XO15_SCI
2089 bool "OLPC XO-1.5 SCI extras"
2090 depends on OLPC && ACPI
2093 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2094 - EC-driven system wakeups
2095 - AC adapter status updates
2096 - Battery status updates
2099 bool "PCEngines ALIX System Support (LED setup)"
2102 This option enables system support for the PCEngines ALIX.
2103 At present this just sets up LEDs for GPIO control on
2104 ALIX2/3/6 boards. However, other system specific setup should
2107 Note: You must still enable the drivers for GPIO and LED support
2108 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2110 Note: You have to set alix.force=1 for boards with Award BIOS.
2116 depends on CPU_SUP_AMD && PCI
2118 source "drivers/pcmcia/Kconfig"
2120 source "drivers/pci/hotplug/Kconfig"
2123 bool "RapidIO support"
2127 If you say Y here, the kernel will include drivers and
2128 infrastructure code to support RapidIO interconnect devices.
2130 source "drivers/rapidio/Kconfig"
2135 menu "Executable file formats / Emulations"
2137 source "fs/Kconfig.binfmt"
2139 config IA32_EMULATION
2140 bool "IA32 Emulation"
2143 select COMPAT_BINFMT_ELF
2145 Include code to run 32-bit programs under a 64-bit kernel. You should
2146 likely turn this on, unless you're 100% sure that you don't have any
2147 32-bit programs left.
2150 tristate "IA32 a.out support"
2151 depends on IA32_EMULATION
2153 Support old a.out binaries in the 32bit emulation.
2157 depends on IA32_EMULATION
2159 config COMPAT_FOR_U64_ALIGNMENT
2163 config SYSVIPC_COMPAT
2165 depends on COMPAT && SYSVIPC
2169 depends on COMPAT && KEYS
2175 config HAVE_ATOMIC_IOMAP
2179 config HAVE_TEXT_POKE_SMP
2181 select STOP_MACHINE if SMP
2183 source "net/Kconfig"
2185 source "drivers/Kconfig"
2187 source "drivers/firmware/Kconfig"
2191 source "arch/x86/Kconfig.debug"
2193 source "security/Kconfig"
2195 source "crypto/Kconfig"
2197 source "arch/x86/kvm/Kconfig"
2199 source "lib/Kconfig"