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
17 select X86_DEV_DMA_OPS
22 select HAVE_AOUT if X86_32
23 select HAVE_UNSTABLE_SCHED_CLOCK
26 select HAVE_PCSPKR_PLATFORM
27 select HAVE_PERF_EVENTS
29 select HAVE_IOREMAP_PROT
32 select HAVE_MEMBLOCK_NODE_MAP
33 select ARCH_DISCARD_MEMBLOCK
34 select ARCH_WANT_OPTIONAL_GPIOLIB
35 select ARCH_WANT_FRAME_POINTERS
37 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
38 select HAVE_KRETPROBES
40 select HAVE_FTRACE_MCOUNT_RECORD
41 select HAVE_FENTRY if X86_64
42 select HAVE_C_RECORDMCOUNT
43 select HAVE_DYNAMIC_FTRACE
44 select HAVE_FUNCTION_TRACER
45 select HAVE_FUNCTION_GRAPH_TRACER
46 select HAVE_FUNCTION_GRAPH_FP_TEST
47 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
48 select HAVE_SYSCALL_TRACEPOINTS
51 select HAVE_ARCH_TRACEHOOK
52 select HAVE_GENERIC_DMA_COHERENT if X86_32
53 select HAVE_EFFICIENT_UNALIGNED_ACCESS
54 select USER_STACKTRACE_SUPPORT
55 select HAVE_REGS_AND_STACK_ACCESS_API
56 select HAVE_DMA_API_DEBUG
57 select HAVE_KERNEL_GZIP
58 select HAVE_KERNEL_BZIP2
59 select HAVE_KERNEL_LZMA
61 select HAVE_KERNEL_LZO
62 select HAVE_HW_BREAKPOINT
63 select HAVE_MIXED_BREAKPOINTS_REGS
65 select HAVE_PERF_EVENTS_NMI
67 select HAVE_PERF_USER_STACK_DUMP
69 select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386
70 select HAVE_CMPXCHG_LOCAL if !M386
71 select HAVE_CMPXCHG_DOUBLE
72 select HAVE_ARCH_KMEMCHECK
73 select HAVE_USER_RETURN_NOTIFIER
74 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
75 select HAVE_ARCH_JUMP_LABEL
76 select HAVE_TEXT_POKE_SMP
77 select HAVE_GENERIC_HARDIRQS
78 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
80 select GENERIC_FIND_FIRST_BIT
81 select GENERIC_IRQ_PROBE
82 select GENERIC_PENDING_IRQ if SMP
83 select GENERIC_IRQ_SHOW
84 select GENERIC_CLOCKEVENTS_MIN_ADJUST
85 select IRQ_FORCED_THREADING
86 select USE_GENERIC_SMP_HELPERS if SMP
87 select HAVE_BPF_JIT if X86_64
89 select ARCH_HAVE_NMI_SAFE_CMPXCHG
91 select DCACHE_WORD_ACCESS
92 select GENERIC_SMP_IDLE_THREAD
93 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
94 select HAVE_ARCH_SECCOMP_FILTER
95 select BUILDTIME_EXTABLE_SORT
96 select GENERIC_CMOS_UPDATE
97 select CLOCKSOURCE_WATCHDOG
98 select GENERIC_CLOCKEVENTS
99 select ARCH_CLOCKSOURCE_DATA if X86_64
100 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
101 select GENERIC_TIME_VSYSCALL if X86_64
102 select KTIME_SCALAR if X86_32
103 select GENERIC_STRNCPY_FROM_USER
104 select GENERIC_STRNLEN_USER
105 select HAVE_RCU_USER_QS if X86_64
106 select HAVE_IRQ_TIME_ACCOUNTING
108 config INSTRUCTION_DECODER
110 depends on KPROBES || PERF_EVENTS || UPROBES
114 default "elf32-i386" if X86_32
115 default "elf64-x86-64" if X86_64
117 config ARCH_DEFCONFIG
119 default "arch/x86/configs/i386_defconfig" if X86_32
120 default "arch/x86/configs/x86_64_defconfig" if X86_64
122 config LOCKDEP_SUPPORT
125 config STACKTRACE_SUPPORT
128 config HAVE_LATENCYTOP_SUPPORT
137 config NEED_DMA_MAP_STATE
139 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
141 config NEED_SG_DMA_LENGTH
144 config GENERIC_ISA_DMA
146 depends on ISA_DMA_API
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
164 depends on ISA_DMA_API
166 config RWSEM_GENERIC_SPINLOCK
170 config RWSEM_XCHGADD_ALGORITHM
174 config GENERIC_CALIBRATE_DELAY
177 config ARCH_HAS_CPU_RELAX
180 config ARCH_HAS_DEFAULT_IDLE
183 config ARCH_HAS_CACHE_LINE_SIZE
186 config ARCH_HAS_CPU_AUTOPROBE
189 config HAVE_SETUP_PER_CPU_AREA
192 config NEED_PER_CPU_EMBED_FIRST_CHUNK
195 config NEED_PER_CPU_PAGE_FIRST_CHUNK
198 config ARCH_HIBERNATION_POSSIBLE
201 config ARCH_SUSPEND_POSSIBLE
212 config ARCH_SUPPORTS_OPTIMIZED_INLINING
215 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
218 config HAVE_INTEL_TXT
220 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
224 depends on X86_32 && SMP
228 depends on X86_64 && SMP
234 config X86_32_LAZY_GS
236 depends on X86_32 && !CC_STACKPROTECTOR
238 config ARCH_HWEIGHT_CFLAGS
240 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
241 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
243 config ARCH_CPU_PROBE_RELEASE
245 depends on HOTPLUG_CPU
247 config ARCH_SUPPORTS_UPROBES
250 source "init/Kconfig"
251 source "kernel/Kconfig.freezer"
253 menu "Processor type and features"
256 bool "DMA memory allocation support" if EXPERT
259 DMA memory allocation support allows devices with less than 32-bit
260 addressing to allocate within the first 16MB of address space.
261 Disable if no such devices will be used.
266 bool "Symmetric multi-processing support"
268 This enables support for systems with more than one CPU. If you have
269 a system with only one CPU, like most personal computers, say N. If
270 you have a system with more than one CPU, say Y.
272 If you say N here, the kernel will run on single and multiprocessor
273 machines, but will use only one CPU of a multiprocessor machine. If
274 you say Y here, the kernel will run on many, but not all,
275 singleprocessor machines. On a singleprocessor machine, the kernel
276 will run faster if you say N here.
278 Note that if you say Y here and choose architecture "586" or
279 "Pentium" under "Processor family", the kernel will not work on 486
280 architectures. Similarly, multiprocessor kernels for the "PPro"
281 architecture may not work on all Pentium based boards.
283 People using multiprocessor machines who say Y here should also say
284 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
285 Management" code will be disabled if you say Y here.
287 See also <file:Documentation/x86/i386/IO-APIC.txt>,
288 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
289 <http://www.tldp.org/docs.html#howto>.
291 If you don't know what to do here, say N.
294 bool "Support x2apic"
295 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
297 This enables x2apic support on CPUs that have this feature.
299 This allows 32-bit apic IDs (so it can support very large systems),
300 and accesses the local apic via MSRs not via mmio.
302 If you don't know what to do here, say N.
305 bool "Enable MPS table" if ACPI
307 depends on X86_LOCAL_APIC
309 For old smp systems that do not have proper acpi support. Newer systems
310 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
313 bool "Support for big SMP systems with more than 8 CPUs"
314 depends on X86_32 && SMP
316 This option is needed for the systems that have more than 8 CPUs
319 config X86_EXTENDED_PLATFORM
320 bool "Support for extended (non-PC) x86 platforms"
323 If you disable this option then the kernel will only support
324 standard PC platforms. (which covers the vast majority of
327 If you enable this option then you'll be able to select support
328 for the following (non-PC) 32 bit x86 platforms:
332 SGI 320/540 (Visual Workstation)
333 STA2X11-based (e.g. Northville)
334 Summit/EXA (IBM x440)
335 Unisys ES7000 IA32 series
336 Moorestown MID devices
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.
343 config X86_EXTENDED_PLATFORM
344 bool "Support for extended (non-PC) x86 platforms"
347 If you disable this option then the kernel will only support
348 standard PC platforms. (which covers the vast majority of
351 If you enable this option then you'll be able to select support
352 for the following (non-PC) 64 bit x86 platforms:
357 If you have one of these systems, or if you want to build a
358 generic distribution kernel, say Y here - otherwise say N.
360 # This is an alphabetically sorted list of 64 bit extended platforms
361 # Please maintain the alphabetic order if and when there are additions
363 bool "Numascale NumaChip"
365 depends on X86_EXTENDED_PLATFORM
368 depends on X86_X2APIC
370 Adds support for Numascale NumaChip large-SMP systems. Needed to
371 enable more than ~168 cores.
372 If you don't have one of these, you should say N here.
376 select PARAVIRT_GUEST
378 depends on X86_64 && PCI
379 depends on X86_EXTENDED_PLATFORM
382 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
383 supposed to run on these EM64T-based machines. Only choose this option
384 if you have one of these machines.
387 bool "SGI Ultraviolet"
389 depends on X86_EXTENDED_PLATFORM
391 depends on X86_X2APIC
393 This option is needed in order to support SGI Ultraviolet systems.
394 If you don't have one of these, you should say N here.
396 # Following is an alphabetically sorted list of 32 bit extended platforms
397 # Please maintain the alphabetic order if and when there are additions
400 bool "CE4100 TV platform"
402 depends on PCI_GODIRECT
404 depends on X86_EXTENDED_PLATFORM
405 select X86_REBOOTFIXUPS
407 select OF_EARLY_FLATTREE
410 Select for the Intel CE media processor (CE4100) SOC.
411 This option compiles in support for the CE4100 SOC for settop
412 boxes and media devices.
414 config X86_WANT_INTEL_MID
415 bool "Intel MID platform support"
417 depends on X86_EXTENDED_PLATFORM
419 Select to build a kernel capable of supporting Intel MID platform
420 systems which do not have the PCI legacy interfaces (Moorestown,
421 Medfield). If you are building for a PC class system say N here.
423 if X86_WANT_INTEL_MID
429 bool "Medfield MID platform"
432 depends on X86_IO_APIC
440 select X86_PLATFORM_DEVICES
441 select MFD_INTEL_MSIC
443 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
444 Internet Device(MID) platform.
445 Unlike standard x86 PCs, Medfield does not have many legacy devices
446 nor standard legacy replacement devices/features. e.g. Medfield does
447 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
452 bool "RDC R-321x SoC"
454 depends on X86_EXTENDED_PLATFORM
456 select X86_REBOOTFIXUPS
458 This option is needed for RDC R-321x system-on-chip, also known
460 If you don't have one of these chips, you should say N here.
462 config X86_32_NON_STANDARD
463 bool "Support non-standard 32-bit SMP architectures"
464 depends on X86_32 && SMP
465 depends on X86_EXTENDED_PLATFORM
467 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
468 STA2X11, default subarchitectures. It is intended for a generic
469 binary kernel. If you select them all, kernel will probe it
470 one by one and will fallback to default.
472 # Alphabetically sorted list of Non standard 32 bit platforms
475 bool "NUMAQ (IBM/Sequent)"
476 depends on X86_32_NON_STANDARD
481 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
482 NUMA multiquad box. This changes the way that processors are
483 bootstrapped, and uses Clustered Logical APIC addressing mode instead
484 of Flat Logical. You will need a new lynxer.elf file to flash your
485 firmware with - send email to <Martin.Bligh@us.ibm.com>.
487 config X86_SUPPORTS_MEMORY_FAILURE
489 # MCE code calls memory_failure():
491 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
492 depends on !X86_NUMAQ
493 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
494 depends on X86_64 || !SPARSEMEM
495 select ARCH_SUPPORTS_MEMORY_FAILURE
498 bool "SGI 320/540 (Visual Workstation)"
499 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
500 depends on X86_32_NON_STANDARD
502 The SGI Visual Workstation series is an IA32-based workstation
503 based on SGI systems chips with some legacy PC hardware attached.
505 Say Y here to create a kernel to run on the SGI 320 or 540.
507 A kernel compiled for the Visual Workstation will run on general
508 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
511 bool "STA2X11 Companion Chip Support"
512 depends on X86_32_NON_STANDARD && PCI
513 select X86_DEV_DMA_OPS
517 select ARCH_REQUIRE_GPIOLIB
520 This adds support for boards based on the STA2X11 IO-Hub,
521 a.k.a. "ConneXt". The chip is used in place of the standard
522 PC chipset, so all "standard" peripherals are missing. If this
523 option is selected the kernel will still be able to boot on
524 standard PC machines.
527 bool "Summit/EXA (IBM x440)"
528 depends on X86_32_NON_STANDARD
530 This option is needed for IBM systems that use the Summit/EXA chipset.
531 In particular, it is needed for the x440.
534 bool "Unisys ES7000 IA32 series"
535 depends on X86_32_NON_STANDARD && X86_BIGSMP
537 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
538 supposed to run on an IA32-based Unisys ES7000 system.
541 tristate "Eurobraille/Iris poweroff module"
544 The Iris machines from EuroBraille do not have APM or ACPI support
545 to shut themselves down properly. A special I/O sequence is
546 needed to do so, which is what this module does at
549 This is only for Iris machines from EuroBraille.
553 config SCHED_OMIT_FRAME_POINTER
555 prompt "Single-depth WCHAN output"
558 Calculate simpler /proc/<PID>/wchan values. If this option
559 is disabled then wchan values will recurse back to the
560 caller function. This provides more accurate wchan values,
561 at the expense of slightly more scheduling overhead.
563 If in doubt, say "Y".
565 menuconfig PARAVIRT_GUEST
566 bool "Paravirtualized guest support"
568 Say Y here to get to see options related to running Linux under
569 various hypervisors. This option alone does not add any kernel code.
571 If you say N, all options in this submenu will be skipped and disabled.
575 config PARAVIRT_TIME_ACCOUNTING
576 bool "Paravirtual steal time accounting"
580 Select this option to enable fine granularity task steal time
581 accounting. Time spent executing other tasks in parallel with
582 the current vCPU is discounted from the vCPU power. To account for
583 that, there can be a small performance impact.
585 If in doubt, say N here.
587 source "arch/x86/xen/Kconfig"
590 bool "KVM paravirtualized clock"
592 select PARAVIRT_CLOCK
594 Turning on this option will allow you to run a paravirtualized clock
595 when running over the KVM hypervisor. Instead of relying on a PIT
596 (or probably other) emulation by the underlying device model, the host
597 provides the guest with timing infrastructure such as time of day, and
601 bool "KVM Guest support"
604 This option enables various optimizations for running under the KVM
607 source "arch/x86/lguest/Kconfig"
610 bool "Enable paravirtualization code"
612 This changes the kernel so it can modify itself when it is run
613 under a hypervisor, potentially improving performance significantly
614 over full virtualization. However, when run without a hypervisor
615 the kernel is theoretically slower and slightly larger.
617 config PARAVIRT_SPINLOCKS
618 bool "Paravirtualization layer for spinlocks"
619 depends on PARAVIRT && SMP && EXPERIMENTAL
621 Paravirtualized spinlocks allow a pvops backend to replace the
622 spinlock implementation with something virtualization-friendly
623 (for example, block the virtual CPU rather than spinning).
625 Unfortunately the downside is an up to 5% performance hit on
626 native kernels, with various workloads.
628 If you are unsure how to answer this question, answer N.
630 config PARAVIRT_CLOCK
635 config PARAVIRT_DEBUG
636 bool "paravirt-ops debugging"
637 depends on PARAVIRT && DEBUG_KERNEL
639 Enable to debug paravirt_ops internals. Specifically, BUG if
640 a paravirt_op is missing when it is called.
648 This option adds a kernel parameter 'memtest', which allows memtest
650 memtest=0, mean disabled; -- default
651 memtest=1, mean do 1 test pattern;
653 memtest=4, mean do 4 test patterns.
654 If you are unsure how to answer this question, answer N.
656 config X86_SUMMIT_NUMA
658 depends on X86_32 && NUMA && X86_32_NON_STANDARD
660 config X86_CYCLONE_TIMER
662 depends on X86_SUMMIT
664 source "arch/x86/Kconfig.cpu"
668 prompt "HPET Timer Support" if X86_32
670 Use the IA-PC HPET (High Precision Event Timer) to manage
671 time in preference to the PIT and RTC, if a HPET is
673 HPET is the next generation timer replacing legacy 8254s.
674 The HPET provides a stable time base on SMP
675 systems, unlike the TSC, but it is more expensive to access,
676 as it is off-chip. You can find the HPET spec at
677 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
679 You can safely choose Y here. However, HPET will only be
680 activated if the platform and the BIOS support this feature.
681 Otherwise the 8254 will be used for timing services.
683 Choose N to continue using the legacy 8254 timer.
685 config HPET_EMULATE_RTC
687 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
690 def_bool y if X86_INTEL_MID
691 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
693 depends on X86_INTEL_MID && SFI
695 APB timer is the replacement for 8254, HPET on X86 MID platforms.
696 The APBT provides a stable time base on SMP
697 systems, unlike the TSC, but it is more expensive to access,
698 as it is off-chip. APB timers are always running regardless of CPU
699 C states, they are used as per CPU clockevent device when possible.
701 # Mark as expert because too many people got it wrong.
702 # The code disables itself when not needed.
705 bool "Enable DMI scanning" if EXPERT
707 Enabled scanning of DMI to identify machine quirks. Say Y
708 here unless you have verified that your setup is not
709 affected by entries in the DMI blacklist. Required by PNP
713 bool "GART IOMMU support" if EXPERT
716 depends on X86_64 && PCI && AMD_NB
718 Support for full DMA access of devices with 32bit memory access only
719 on systems with more than 3GB. This is usually needed for USB,
720 sound, many IDE/SATA chipsets and some other devices.
721 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
722 based hardware IOMMU and a software bounce buffer based IOMMU used
723 on Intel systems and as fallback.
724 The code is only active when needed (enough memory and limited
725 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
729 bool "IBM Calgary IOMMU support"
731 depends on X86_64 && PCI && EXPERIMENTAL
733 Support for hardware IOMMUs in IBM's xSeries x366 and x460
734 systems. Needed to run systems with more than 3GB of memory
735 properly with 32-bit PCI devices that do not support DAC
736 (Double Address Cycle). Calgary also supports bus level
737 isolation, where all DMAs pass through the IOMMU. This
738 prevents them from going anywhere except their intended
739 destination. This catches hard-to-find kernel bugs and
740 mis-behaving drivers and devices that do not use the DMA-API
741 properly to set up their DMA buffers. The IOMMU can be
742 turned off at boot time with the iommu=off parameter.
743 Normally the kernel will make the right choice by itself.
746 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
748 prompt "Should Calgary be enabled by default?"
749 depends on CALGARY_IOMMU
751 Should Calgary be enabled by default? if you choose 'y', Calgary
752 will be used (if it exists). If you choose 'n', Calgary will not be
753 used even if it exists. If you choose 'n' and would like to use
754 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
757 # need this always selected by IOMMU for the VIA workaround
761 Support for software bounce buffers used on x86-64 systems
762 which don't have a hardware IOMMU. Using this PCI devices
763 which can only access 32-bits of memory can be used on systems
764 with more than 3 GB of memory.
769 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
772 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
773 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
774 select CPUMASK_OFFSTACK
776 Enable maximum number of CPUS and NUMA Nodes for this architecture.
780 int "Maximum number of CPUs" if SMP && !MAXSMP
781 range 2 8 if SMP && X86_32 && !X86_BIGSMP
782 range 2 512 if SMP && !MAXSMP
784 default "4096" if MAXSMP
785 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
788 This allows you to specify the maximum number of CPUs which this
789 kernel will support. The maximum supported value is 512 and the
790 minimum value which makes sense is 2.
792 This is purely to save memory - each supported CPU adds
793 approximately eight kilobytes to the kernel image.
796 bool "SMT (Hyperthreading) scheduler support"
799 SMT scheduler support improves the CPU scheduler's decision making
800 when dealing with Intel Pentium 4 chips with HyperThreading at a
801 cost of slightly increased overhead in some places. If unsure say
806 prompt "Multi-core scheduler support"
809 Multi-core scheduler support improves the CPU scheduler's decision
810 making when dealing with multi-core CPU chips at a cost of slightly
811 increased overhead in some places. If unsure say N here.
813 source "kernel/Kconfig.preempt"
816 bool "Local APIC support on uniprocessors"
817 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
819 A local APIC (Advanced Programmable Interrupt Controller) is an
820 integrated interrupt controller in the CPU. If you have a single-CPU
821 system which has a processor with a local APIC, you can say Y here to
822 enable and use it. If you say Y here even though your machine doesn't
823 have a local APIC, then the kernel will still run with no slowdown at
824 all. The local APIC supports CPU-generated self-interrupts (timer,
825 performance counters), and the NMI watchdog which detects hard
829 bool "IO-APIC support on uniprocessors"
830 depends on X86_UP_APIC
832 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
833 SMP-capable replacement for PC-style interrupt controllers. Most
834 SMP systems and many recent uniprocessor systems have one.
836 If you have a single-CPU system with an IO-APIC, you can say Y here
837 to use it. If you say Y here even though your machine doesn't have
838 an IO-APIC, then the kernel will still run with no slowdown at all.
840 config X86_LOCAL_APIC
842 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
846 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
848 config X86_VISWS_APIC
850 depends on X86_32 && X86_VISWS
852 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
853 bool "Reroute for broken boot IRQs"
854 depends on X86_IO_APIC
856 This option enables a workaround that fixes a source of
857 spurious interrupts. This is recommended when threaded
858 interrupt handling is used on systems where the generation of
859 superfluous "boot interrupts" cannot be disabled.
861 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
862 entry in the chipset's IO-APIC is masked (as, e.g. the RT
863 kernel does during interrupt handling). On chipsets where this
864 boot IRQ generation cannot be disabled, this workaround keeps
865 the original IRQ line masked so that only the equivalent "boot
866 IRQ" is delivered to the CPUs. The workaround also tells the
867 kernel to set up the IRQ handler on the boot IRQ line. In this
868 way only one interrupt is delivered to the kernel. Otherwise
869 the spurious second interrupt may cause the kernel to bring
870 down (vital) interrupt lines.
872 Only affects "broken" chipsets. Interrupt sharing may be
873 increased on these systems.
876 bool "Machine Check / overheating reporting"
878 Machine Check support allows the processor to notify the
879 kernel if it detects a problem (e.g. overheating, data corruption).
880 The action the kernel takes depends on the severity of the problem,
881 ranging from warning messages to halting the machine.
885 prompt "Intel MCE features"
886 depends on X86_MCE && X86_LOCAL_APIC
888 Additional support for intel specific MCE features such as
893 prompt "AMD MCE features"
894 depends on X86_MCE && X86_LOCAL_APIC
896 Additional support for AMD specific MCE features such as
897 the DRAM Error Threshold.
899 config X86_ANCIENT_MCE
900 bool "Support for old Pentium 5 / WinChip machine checks"
901 depends on X86_32 && X86_MCE
903 Include support for machine check handling on old Pentium 5 or WinChip
904 systems. These typically need to be enabled explicitely on the command
907 config X86_MCE_THRESHOLD
908 depends on X86_MCE_AMD || X86_MCE_INTEL
911 config X86_MCE_INJECT
913 tristate "Machine check injector support"
915 Provide support for injecting machine checks for testing purposes.
916 If you don't know what a machine check is and you don't do kernel
917 QA it is safe to say n.
919 config X86_THERMAL_VECTOR
921 depends on X86_MCE_INTEL
924 bool "Enable VM86 support" if EXPERT
928 This option is required by programs like DOSEMU to run 16-bit legacy
929 code on X86 processors. It also may be needed by software like
930 XFree86 to initialize some video cards via BIOS. Disabling this
931 option saves about 6k.
934 tristate "Toshiba Laptop support"
937 This adds a driver to safely access the System Management Mode of
938 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
939 not work on models with a Phoenix BIOS. The System Management Mode
940 is used to set the BIOS and power saving options on Toshiba portables.
942 For information on utilities to make use of this driver see the
943 Toshiba Linux utilities web site at:
944 <http://www.buzzard.org.uk/toshiba/>.
946 Say Y if you intend to run this kernel on a Toshiba portable.
950 tristate "Dell laptop support"
953 This adds a driver to safely access the System Management Mode
954 of the CPU on the Dell Inspiron 8000. The System Management Mode
955 is used to read cpu temperature and cooling fan status and to
956 control the fans on the I8K portables.
958 This driver has been tested only on the Inspiron 8000 but it may
959 also work with other Dell laptops. You can force loading on other
960 models by passing the parameter `force=1' to the module. Use at
963 For information on utilities to make use of this driver see the
964 I8K Linux utilities web site at:
965 <http://people.debian.org/~dz/i8k/>
967 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
970 config X86_REBOOTFIXUPS
971 bool "Enable X86 board specific fixups for reboot"
974 This enables chipset and/or board specific fixups to be done
975 in order to get reboot to work correctly. This is only needed on
976 some combinations of hardware and BIOS. The symptom, for which
977 this config is intended, is when reboot ends with a stalled/hung
980 Currently, the only fixup is for the Geode machines using
981 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
983 Say Y if you want to enable the fixup. Currently, it's safe to
984 enable this option even if you don't need it.
988 tristate "/dev/cpu/microcode - microcode support"
991 If you say Y here, you will be able to update the microcode on
992 certain Intel and AMD processors. The Intel support is for the
993 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
994 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
995 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
996 You will obviously need the actual microcode binary data itself
997 which is not shipped with the Linux kernel.
999 This option selects the general module only, you need to select
1000 at least one vendor specific module as well.
1002 To compile this driver as a module, choose M here: the
1003 module will be called microcode.
1005 config MICROCODE_INTEL
1006 bool "Intel microcode patch loading support"
1007 depends on MICROCODE
1011 This options enables microcode patch loading support for Intel
1014 For latest news and information on obtaining all the required
1015 Intel ingredients for this driver, check:
1016 <http://www.urbanmyth.org/microcode/>.
1018 config MICROCODE_AMD
1019 bool "AMD microcode patch loading support"
1020 depends on MICROCODE
1023 If you select this option, microcode patch loading support for AMD
1024 processors will be enabled.
1026 config MICROCODE_OLD_INTERFACE
1028 depends on MICROCODE
1031 tristate "/dev/cpu/*/msr - Model-specific register support"
1033 This device gives privileged processes access to the x86
1034 Model-Specific Registers (MSRs). It is a character device with
1035 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1036 MSR accesses are directed to a specific CPU on multi-processor
1040 tristate "/dev/cpu/*/cpuid - CPU information support"
1042 This device gives processes access to the x86 CPUID instruction to
1043 be executed on a specific processor. It is a character device
1044 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1048 prompt "High Memory Support"
1049 default HIGHMEM64G if X86_NUMAQ
1055 depends on !X86_NUMAQ
1057 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1058 However, the address space of 32-bit x86 processors is only 4
1059 Gigabytes large. That means that, if you have a large amount of
1060 physical memory, not all of it can be "permanently mapped" by the
1061 kernel. The physical memory that's not permanently mapped is called
1064 If you are compiling a kernel which will never run on a machine with
1065 more than 1 Gigabyte total physical RAM, answer "off" here (default
1066 choice and suitable for most users). This will result in a "3GB/1GB"
1067 split: 3GB are mapped so that each process sees a 3GB virtual memory
1068 space and the remaining part of the 4GB virtual memory space is used
1069 by the kernel to permanently map as much physical memory as
1072 If the machine has between 1 and 4 Gigabytes physical RAM, then
1075 If more than 4 Gigabytes is used then answer "64GB" here. This
1076 selection turns Intel PAE (Physical Address Extension) mode on.
1077 PAE implements 3-level paging on IA32 processors. PAE is fully
1078 supported by Linux, PAE mode is implemented on all recent Intel
1079 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1080 then the kernel will not boot on CPUs that don't support PAE!
1082 The actual amount of total physical memory will either be
1083 auto detected or can be forced by using a kernel command line option
1084 such as "mem=256M". (Try "man bootparam" or see the documentation of
1085 your boot loader (lilo or loadlin) about how to pass options to the
1086 kernel at boot time.)
1088 If unsure, say "off".
1092 depends on !X86_NUMAQ
1094 Select this if you have a 32-bit processor and between 1 and 4
1095 gigabytes of physical RAM.
1099 depends on !M386 && !M486
1102 Select this if you have a 32-bit processor and more than 4
1103 gigabytes of physical RAM.
1108 depends on EXPERIMENTAL
1109 prompt "Memory split" if EXPERT
1113 Select the desired split between kernel and user memory.
1115 If the address range available to the kernel is less than the
1116 physical memory installed, the remaining memory will be available
1117 as "high memory". Accessing high memory is a little more costly
1118 than low memory, as it needs to be mapped into the kernel first.
1119 Note that increasing the kernel address space limits the range
1120 available to user programs, making the address space there
1121 tighter. Selecting anything other than the default 3G/1G split
1122 will also likely make your kernel incompatible with binary-only
1125 If you are not absolutely sure what you are doing, leave this
1129 bool "3G/1G user/kernel split"
1130 config VMSPLIT_3G_OPT
1132 bool "3G/1G user/kernel split (for full 1G low memory)"
1134 bool "2G/2G user/kernel split"
1135 config VMSPLIT_2G_OPT
1137 bool "2G/2G user/kernel split (for full 2G low memory)"
1139 bool "1G/3G user/kernel split"
1144 default 0xB0000000 if VMSPLIT_3G_OPT
1145 default 0x80000000 if VMSPLIT_2G
1146 default 0x78000000 if VMSPLIT_2G_OPT
1147 default 0x40000000 if VMSPLIT_1G
1153 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1156 bool "PAE (Physical Address Extension) Support"
1157 depends on X86_32 && !HIGHMEM4G
1159 PAE is required for NX support, and furthermore enables
1160 larger swapspace support for non-overcommit purposes. It
1161 has the cost of more pagetable lookup overhead, and also
1162 consumes more pagetable space per process.
1164 config ARCH_PHYS_ADDR_T_64BIT
1166 depends on X86_64 || X86_PAE
1168 config ARCH_DMA_ADDR_T_64BIT
1170 depends on X86_64 || HIGHMEM64G
1172 config DIRECT_GBPAGES
1173 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1177 Allow the kernel linear mapping to use 1GB pages on CPUs that
1178 support it. This can improve the kernel's performance a tiny bit by
1179 reducing TLB pressure. If in doubt, say "Y".
1181 # Common NUMA Features
1183 bool "Numa Memory Allocation and Scheduler Support"
1185 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1186 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1188 Enable NUMA (Non Uniform Memory Access) support.
1190 The kernel will try to allocate memory used by a CPU on the
1191 local memory controller of the CPU and add some more
1192 NUMA awareness to the kernel.
1194 For 64-bit this is recommended if the system is Intel Core i7
1195 (or later), AMD Opteron, or EM64T NUMA.
1197 For 32-bit this is only needed on (rare) 32-bit-only platforms
1198 that support NUMA topologies, such as NUMAQ / Summit, or if you
1199 boot a 32-bit kernel on a 64-bit NUMA platform.
1201 Otherwise, you should say N.
1203 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1204 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1208 prompt "Old style AMD Opteron NUMA detection"
1209 depends on X86_64 && NUMA && PCI
1211 Enable AMD NUMA node topology detection. You should say Y here if
1212 you have a multi processor AMD system. This uses an old method to
1213 read the NUMA configuration directly from the builtin Northbridge
1214 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1215 which also takes priority if both are compiled in.
1217 config X86_64_ACPI_NUMA
1219 prompt "ACPI NUMA detection"
1220 depends on X86_64 && NUMA && ACPI && PCI
1223 Enable ACPI SRAT based node topology detection.
1225 # Some NUMA nodes have memory ranges that span
1226 # other nodes. Even though a pfn is valid and
1227 # between a node's start and end pfns, it may not
1228 # reside on that node. See memmap_init_zone()
1230 config NODES_SPAN_OTHER_NODES
1232 depends on X86_64_ACPI_NUMA
1235 bool "NUMA emulation"
1238 Enable NUMA emulation. A flat machine will be split
1239 into virtual nodes when booted with "numa=fake=N", where N is the
1240 number of nodes. This is only useful for debugging.
1243 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1245 default "10" if MAXSMP
1246 default "6" if X86_64
1247 default "4" if X86_NUMAQ
1249 depends on NEED_MULTIPLE_NODES
1251 Specify the maximum number of NUMA Nodes available on the target
1252 system. Increases memory reserved to accommodate various tables.
1254 config HAVE_ARCH_ALLOC_REMAP
1256 depends on X86_32 && NUMA
1258 config ARCH_HAVE_MEMORY_PRESENT
1260 depends on X86_32 && DISCONTIGMEM
1262 config NEED_NODE_MEMMAP_SIZE
1264 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1266 config ARCH_FLATMEM_ENABLE
1268 depends on X86_32 && !NUMA
1270 config ARCH_DISCONTIGMEM_ENABLE
1272 depends on NUMA && X86_32
1274 config ARCH_DISCONTIGMEM_DEFAULT
1276 depends on NUMA && X86_32
1278 config ARCH_SPARSEMEM_ENABLE
1280 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1281 select SPARSEMEM_STATIC if X86_32
1282 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1284 config ARCH_SPARSEMEM_DEFAULT
1288 config ARCH_SELECT_MEMORY_MODEL
1290 depends on ARCH_SPARSEMEM_ENABLE
1292 config ARCH_MEMORY_PROBE
1294 depends on X86_64 && MEMORY_HOTPLUG
1296 config ARCH_PROC_KCORE_TEXT
1298 depends on X86_64 && PROC_KCORE
1300 config ILLEGAL_POINTER_VALUE
1303 default 0xdead000000000000 if X86_64
1308 bool "Allocate 3rd-level pagetables from highmem"
1311 The VM uses one page table entry for each page of physical memory.
1312 For systems with a lot of RAM, this can be wasteful of precious
1313 low memory. Setting this option will put user-space page table
1314 entries in high memory.
1316 config X86_CHECK_BIOS_CORRUPTION
1317 bool "Check for low memory corruption"
1319 Periodically check for memory corruption in low memory, which
1320 is suspected to be caused by BIOS. Even when enabled in the
1321 configuration, it is disabled at runtime. Enable it by
1322 setting "memory_corruption_check=1" on the kernel command
1323 line. By default it scans the low 64k of memory every 60
1324 seconds; see the memory_corruption_check_size and
1325 memory_corruption_check_period parameters in
1326 Documentation/kernel-parameters.txt to adjust this.
1328 When enabled with the default parameters, this option has
1329 almost no overhead, as it reserves a relatively small amount
1330 of memory and scans it infrequently. It both detects corruption
1331 and prevents it from affecting the running system.
1333 It is, however, intended as a diagnostic tool; if repeatable
1334 BIOS-originated corruption always affects the same memory,
1335 you can use memmap= to prevent the kernel from using that
1338 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1339 bool "Set the default setting of memory_corruption_check"
1340 depends on X86_CHECK_BIOS_CORRUPTION
1343 Set whether the default state of memory_corruption_check is
1346 config X86_RESERVE_LOW
1347 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1351 Specify the amount of low memory to reserve for the BIOS.
1353 The first page contains BIOS data structures that the kernel
1354 must not use, so that page must always be reserved.
1356 By default we reserve the first 64K of physical RAM, as a
1357 number of BIOSes are known to corrupt that memory range
1358 during events such as suspend/resume or monitor cable
1359 insertion, so it must not be used by the kernel.
1361 You can set this to 4 if you are absolutely sure that you
1362 trust the BIOS to get all its memory reservations and usages
1363 right. If you know your BIOS have problems beyond the
1364 default 64K area, you can set this to 640 to avoid using the
1365 entire low memory range.
1367 If you have doubts about the BIOS (e.g. suspend/resume does
1368 not work or there's kernel crashes after certain hardware
1369 hotplug events) then you might want to enable
1370 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1371 typical corruption patterns.
1373 Leave this to the default value of 64 if you are unsure.
1375 config MATH_EMULATION
1377 prompt "Math emulation" if X86_32
1379 Linux can emulate a math coprocessor (used for floating point
1380 operations) if you don't have one. 486DX and Pentium processors have
1381 a math coprocessor built in, 486SX and 386 do not, unless you added
1382 a 487DX or 387, respectively. (The messages during boot time can
1383 give you some hints here ["man dmesg"].) Everyone needs either a
1384 coprocessor or this emulation.
1386 If you don't have a math coprocessor, you need to say Y here; if you
1387 say Y here even though you have a coprocessor, the coprocessor will
1388 be used nevertheless. (This behavior can be changed with the kernel
1389 command line option "no387", which comes handy if your coprocessor
1390 is broken. Try "man bootparam" or see the documentation of your boot
1391 loader (lilo or loadlin) about how to pass options to the kernel at
1392 boot time.) This means that it is a good idea to say Y here if you
1393 intend to use this kernel on different machines.
1395 More information about the internals of the Linux math coprocessor
1396 emulation can be found in <file:arch/x86/math-emu/README>.
1398 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1399 kernel, it won't hurt.
1403 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1405 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1406 the Memory Type Range Registers (MTRRs) may be used to control
1407 processor access to memory ranges. This is most useful if you have
1408 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1409 allows bus write transfers to be combined into a larger transfer
1410 before bursting over the PCI/AGP bus. This can increase performance
1411 of image write operations 2.5 times or more. Saying Y here creates a
1412 /proc/mtrr file which may be used to manipulate your processor's
1413 MTRRs. Typically the X server should use this.
1415 This code has a reasonably generic interface so that similar
1416 control registers on other processors can be easily supported
1419 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1420 Registers (ARRs) which provide a similar functionality to MTRRs. For
1421 these, the ARRs are used to emulate the MTRRs.
1422 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1423 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1424 write-combining. All of these processors are supported by this code
1425 and it makes sense to say Y here if you have one of them.
1427 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1428 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1429 can lead to all sorts of problems, so it's good to say Y here.
1431 You can safely say Y even if your machine doesn't have MTRRs, you'll
1432 just add about 9 KB to your kernel.
1434 See <file:Documentation/x86/mtrr.txt> for more information.
1436 config MTRR_SANITIZER
1438 prompt "MTRR cleanup support"
1441 Convert MTRR layout from continuous to discrete, so X drivers can
1442 add writeback entries.
1444 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1445 The largest mtrr entry size for a continuous block can be set with
1450 config MTRR_SANITIZER_ENABLE_DEFAULT
1451 int "MTRR cleanup enable value (0-1)"
1454 depends on MTRR_SANITIZER
1456 Enable mtrr cleanup default value
1458 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1459 int "MTRR cleanup spare reg num (0-7)"
1462 depends on MTRR_SANITIZER
1464 mtrr cleanup spare entries default, it can be changed via
1465 mtrr_spare_reg_nr=N on the kernel command line.
1469 prompt "x86 PAT support" if EXPERT
1472 Use PAT attributes to setup page level cache control.
1474 PATs are the modern equivalents of MTRRs and are much more
1475 flexible than MTRRs.
1477 Say N here if you see bootup problems (boot crash, boot hang,
1478 spontaneous reboots) or a non-working video driver.
1482 config ARCH_USES_PG_UNCACHED
1488 prompt "x86 architectural random number generator" if EXPERT
1490 Enable the x86 architectural RDRAND instruction
1491 (Intel Bull Mountain technology) to generate random numbers.
1492 If supported, this is a high bandwidth, cryptographically
1493 secure hardware random number generator.
1496 bool "EFI runtime service support"
1499 This enables the kernel to use EFI runtime services that are
1500 available (such as the EFI variable services).
1502 This option is only useful on systems that have EFI firmware.
1503 In addition, you should use the latest ELILO loader available
1504 at <http://elilo.sourceforge.net> in order to take advantage
1505 of EFI runtime services. However, even with this option, the
1506 resultant kernel should continue to boot on existing non-EFI
1510 bool "EFI stub support"
1513 This kernel feature allows a bzImage to be loaded directly
1514 by EFI firmware without the use of a bootloader.
1516 See Documentation/x86/efi-stub.txt for more information.
1520 prompt "Enable seccomp to safely compute untrusted bytecode"
1522 This kernel feature is useful for number crunching applications
1523 that may need to compute untrusted bytecode during their
1524 execution. By using pipes or other transports made available to
1525 the process as file descriptors supporting the read/write
1526 syscalls, it's possible to isolate those applications in
1527 their own address space using seccomp. Once seccomp is
1528 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1529 and the task is only allowed to execute a few safe syscalls
1530 defined by each seccomp mode.
1532 If unsure, say Y. Only embedded should say N here.
1534 config CC_STACKPROTECTOR
1535 bool "Enable -fstack-protector buffer overflow detection"
1537 This option turns on the -fstack-protector GCC feature. This
1538 feature puts, at the beginning of functions, a canary value on
1539 the stack just before the return address, and validates
1540 the value just before actually returning. Stack based buffer
1541 overflows (that need to overwrite this return address) now also
1542 overwrite the canary, which gets detected and the attack is then
1543 neutralized via a kernel panic.
1545 This feature requires gcc version 4.2 or above, or a distribution
1546 gcc with the feature backported. Older versions are automatically
1547 detected and for those versions, this configuration option is
1548 ignored. (and a warning is printed during bootup)
1550 source kernel/Kconfig.hz
1553 bool "kexec system call"
1555 kexec is a system call that implements the ability to shutdown your
1556 current kernel, and to start another kernel. It is like a reboot
1557 but it is independent of the system firmware. And like a reboot
1558 you can start any kernel with it, not just Linux.
1560 The name comes from the similarity to the exec system call.
1562 It is an ongoing process to be certain the hardware in a machine
1563 is properly shutdown, so do not be surprised if this code does not
1564 initially work for you. It may help to enable device hotplugging
1565 support. As of this writing the exact hardware interface is
1566 strongly in flux, so no good recommendation can be made.
1569 bool "kernel crash dumps"
1570 depends on X86_64 || (X86_32 && HIGHMEM)
1572 Generate crash dump after being started by kexec.
1573 This should be normally only set in special crash dump kernels
1574 which are loaded in the main kernel with kexec-tools into
1575 a specially reserved region and then later executed after
1576 a crash by kdump/kexec. The crash dump kernel must be compiled
1577 to a memory address not used by the main kernel or BIOS using
1578 PHYSICAL_START, or it must be built as a relocatable image
1579 (CONFIG_RELOCATABLE=y).
1580 For more details see Documentation/kdump/kdump.txt
1583 bool "kexec jump (EXPERIMENTAL)"
1584 depends on EXPERIMENTAL
1585 depends on KEXEC && HIBERNATION
1587 Jump between original kernel and kexeced kernel and invoke
1588 code in physical address mode via KEXEC
1590 config PHYSICAL_START
1591 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1594 This gives the physical address where the kernel is loaded.
1596 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1597 bzImage will decompress itself to above physical address and
1598 run from there. Otherwise, bzImage will run from the address where
1599 it has been loaded by the boot loader and will ignore above physical
1602 In normal kdump cases one does not have to set/change this option
1603 as now bzImage can be compiled as a completely relocatable image
1604 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1605 address. This option is mainly useful for the folks who don't want
1606 to use a bzImage for capturing the crash dump and want to use a
1607 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1608 to be specifically compiled to run from a specific memory area
1609 (normally a reserved region) and this option comes handy.
1611 So if you are using bzImage for capturing the crash dump,
1612 leave the value here unchanged to 0x1000000 and set
1613 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1614 for capturing the crash dump change this value to start of
1615 the reserved region. In other words, it can be set based on
1616 the "X" value as specified in the "crashkernel=YM@XM"
1617 command line boot parameter passed to the panic-ed
1618 kernel. Please take a look at Documentation/kdump/kdump.txt
1619 for more details about crash dumps.
1621 Usage of bzImage for capturing the crash dump is recommended as
1622 one does not have to build two kernels. Same kernel can be used
1623 as production kernel and capture kernel. Above option should have
1624 gone away after relocatable bzImage support is introduced. But it
1625 is present because there are users out there who continue to use
1626 vmlinux for dump capture. This option should go away down the
1629 Don't change this unless you know what you are doing.
1632 bool "Build a relocatable kernel"
1635 This builds a kernel image that retains relocation information
1636 so it can be loaded someplace besides the default 1MB.
1637 The relocations tend to make the kernel binary about 10% larger,
1638 but are discarded at runtime.
1640 One use is for the kexec on panic case where the recovery kernel
1641 must live at a different physical address than the primary
1644 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1645 it has been loaded at and the compile time physical address
1646 (CONFIG_PHYSICAL_START) is ignored.
1648 # Relocation on x86-32 needs some additional build support
1649 config X86_NEED_RELOCS
1651 depends on X86_32 && RELOCATABLE
1653 config PHYSICAL_ALIGN
1654 hex "Alignment value to which kernel should be aligned" if X86_32
1656 range 0x2000 0x1000000
1658 This value puts the alignment restrictions on physical address
1659 where kernel is loaded and run from. Kernel is compiled for an
1660 address which meets above alignment restriction.
1662 If bootloader loads the kernel at a non-aligned address and
1663 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1664 address aligned to above value and run from there.
1666 If bootloader loads the kernel at a non-aligned address and
1667 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1668 load address and decompress itself to the address it has been
1669 compiled for and run from there. The address for which kernel is
1670 compiled already meets above alignment restrictions. Hence the
1671 end result is that kernel runs from a physical address meeting
1672 above alignment restrictions.
1674 Don't change this unless you know what you are doing.
1677 bool "Support for hot-pluggable CPUs"
1678 depends on SMP && HOTPLUG
1680 Say Y here to allow turning CPUs off and on. CPUs can be
1681 controlled through /sys/devices/system/cpu.
1682 ( Note: power management support will enable this option
1683 automatically on SMP systems. )
1684 Say N if you want to disable CPU hotplug.
1688 prompt "Compat VDSO support"
1689 depends on X86_32 || IA32_EMULATION
1691 Map the 32-bit VDSO to the predictable old-style address too.
1693 Say N here if you are running a sufficiently recent glibc
1694 version (2.3.3 or later), to remove the high-mapped
1695 VDSO mapping and to exclusively use the randomized VDSO.
1700 bool "Built-in kernel command line"
1702 Allow for specifying boot arguments to the kernel at
1703 build time. On some systems (e.g. embedded ones), it is
1704 necessary or convenient to provide some or all of the
1705 kernel boot arguments with the kernel itself (that is,
1706 to not rely on the boot loader to provide them.)
1708 To compile command line arguments into the kernel,
1709 set this option to 'Y', then fill in the
1710 the boot arguments in CONFIG_CMDLINE.
1712 Systems with fully functional boot loaders (i.e. non-embedded)
1713 should leave this option set to 'N'.
1716 string "Built-in kernel command string"
1717 depends on CMDLINE_BOOL
1720 Enter arguments here that should be compiled into the kernel
1721 image and used at boot time. If the boot loader provides a
1722 command line at boot time, it is appended to this string to
1723 form the full kernel command line, when the system boots.
1725 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1726 change this behavior.
1728 In most cases, the command line (whether built-in or provided
1729 by the boot loader) should specify the device for the root
1732 config CMDLINE_OVERRIDE
1733 bool "Built-in command line overrides boot loader arguments"
1734 depends on CMDLINE_BOOL
1736 Set this option to 'Y' to have the kernel ignore the boot loader
1737 command line, and use ONLY the built-in command line.
1739 This is used to work around broken boot loaders. This should
1740 be set to 'N' under normal conditions.
1744 config ARCH_ENABLE_MEMORY_HOTPLUG
1746 depends on X86_64 || (X86_32 && HIGHMEM)
1748 config ARCH_ENABLE_MEMORY_HOTREMOVE
1750 depends on MEMORY_HOTPLUG
1752 config USE_PERCPU_NUMA_NODE_ID
1756 menu "Power management and ACPI options"
1758 config ARCH_HIBERNATION_HEADER
1760 depends on X86_64 && HIBERNATION
1762 source "kernel/power/Kconfig"
1764 source "drivers/acpi/Kconfig"
1766 source "drivers/sfi/Kconfig"
1773 tristate "APM (Advanced Power Management) BIOS support"
1774 depends on X86_32 && PM_SLEEP
1776 APM is a BIOS specification for saving power using several different
1777 techniques. This is mostly useful for battery powered laptops with
1778 APM compliant BIOSes. If you say Y here, the system time will be
1779 reset after a RESUME operation, the /proc/apm device will provide
1780 battery status information, and user-space programs will receive
1781 notification of APM "events" (e.g. battery status change).
1783 If you select "Y" here, you can disable actual use of the APM
1784 BIOS by passing the "apm=off" option to the kernel at boot time.
1786 Note that the APM support is almost completely disabled for
1787 machines with more than one CPU.
1789 In order to use APM, you will need supporting software. For location
1790 and more information, read <file:Documentation/power/apm-acpi.txt>
1791 and the Battery Powered Linux mini-HOWTO, available from
1792 <http://www.tldp.org/docs.html#howto>.
1794 This driver does not spin down disk drives (see the hdparm(8)
1795 manpage ("man 8 hdparm") for that), and it doesn't turn off
1796 VESA-compliant "green" monitors.
1798 This driver does not support the TI 4000M TravelMate and the ACER
1799 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1800 desktop machines also don't have compliant BIOSes, and this driver
1801 may cause those machines to panic during the boot phase.
1803 Generally, if you don't have a battery in your machine, there isn't
1804 much point in using this driver and you should say N. If you get
1805 random kernel OOPSes or reboots that don't seem to be related to
1806 anything, try disabling/enabling this option (or disabling/enabling
1809 Some other things you should try when experiencing seemingly random,
1812 1) make sure that you have enough swap space and that it is
1814 2) pass the "no-hlt" option to the kernel
1815 3) switch on floating point emulation in the kernel and pass
1816 the "no387" option to the kernel
1817 4) pass the "floppy=nodma" option to the kernel
1818 5) pass the "mem=4M" option to the kernel (thereby disabling
1819 all but the first 4 MB of RAM)
1820 6) make sure that the CPU is not over clocked.
1821 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1822 8) disable the cache from your BIOS settings
1823 9) install a fan for the video card or exchange video RAM
1824 10) install a better fan for the CPU
1825 11) exchange RAM chips
1826 12) exchange the motherboard.
1828 To compile this driver as a module, choose M here: the
1829 module will be called apm.
1833 config APM_IGNORE_USER_SUSPEND
1834 bool "Ignore USER SUSPEND"
1836 This option will ignore USER SUSPEND requests. On machines with a
1837 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1838 series notebooks, it is necessary to say Y because of a BIOS bug.
1840 config APM_DO_ENABLE
1841 bool "Enable PM at boot time"
1843 Enable APM features at boot time. From page 36 of the APM BIOS
1844 specification: "When disabled, the APM BIOS does not automatically
1845 power manage devices, enter the Standby State, enter the Suspend
1846 State, or take power saving steps in response to CPU Idle calls."
1847 This driver will make CPU Idle calls when Linux is idle (unless this
1848 feature is turned off -- see "Do CPU IDLE calls", below). This
1849 should always save battery power, but more complicated APM features
1850 will be dependent on your BIOS implementation. You may need to turn
1851 this option off if your computer hangs at boot time when using APM
1852 support, or if it beeps continuously instead of suspending. Turn
1853 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1854 T400CDT. This is off by default since most machines do fine without
1858 bool "Make CPU Idle calls when idle"
1860 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1861 On some machines, this can activate improved power savings, such as
1862 a slowed CPU clock rate, when the machine is idle. These idle calls
1863 are made after the idle loop has run for some length of time (e.g.,
1864 333 mS). On some machines, this will cause a hang at boot time or
1865 whenever the CPU becomes idle. (On machines with more than one CPU,
1866 this option does nothing.)
1868 config APM_DISPLAY_BLANK
1869 bool "Enable console blanking using APM"
1871 Enable console blanking using the APM. Some laptops can use this to
1872 turn off the LCD backlight when the screen blanker of the Linux
1873 virtual console blanks the screen. Note that this is only used by
1874 the virtual console screen blanker, and won't turn off the backlight
1875 when using the X Window system. This also doesn't have anything to
1876 do with your VESA-compliant power-saving monitor. Further, this
1877 option doesn't work for all laptops -- it might not turn off your
1878 backlight at all, or it might print a lot of errors to the console,
1879 especially if you are using gpm.
1881 config APM_ALLOW_INTS
1882 bool "Allow interrupts during APM BIOS calls"
1884 Normally we disable external interrupts while we are making calls to
1885 the APM BIOS as a measure to lessen the effects of a badly behaving
1886 BIOS implementation. The BIOS should reenable interrupts if it
1887 needs to. Unfortunately, some BIOSes do not -- especially those in
1888 many of the newer IBM Thinkpads. If you experience hangs when you
1889 suspend, try setting this to Y. Otherwise, say N.
1893 source "drivers/cpufreq/Kconfig"
1895 source "drivers/cpuidle/Kconfig"
1897 source "drivers/idle/Kconfig"
1902 menu "Bus options (PCI etc.)"
1907 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1909 Find out whether you have a PCI motherboard. PCI is the name of a
1910 bus system, i.e. the way the CPU talks to the other stuff inside
1911 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1912 VESA. If you have PCI, say Y, otherwise N.
1915 prompt "PCI access mode"
1916 depends on X86_32 && PCI
1919 On PCI systems, the BIOS can be used to detect the PCI devices and
1920 determine their configuration. However, some old PCI motherboards
1921 have BIOS bugs and may crash if this is done. Also, some embedded
1922 PCI-based systems don't have any BIOS at all. Linux can also try to
1923 detect the PCI hardware directly without using the BIOS.
1925 With this option, you can specify how Linux should detect the
1926 PCI devices. If you choose "BIOS", the BIOS will be used,
1927 if you choose "Direct", the BIOS won't be used, and if you
1928 choose "MMConfig", then PCI Express MMCONFIG will be used.
1929 If you choose "Any", the kernel will try MMCONFIG, then the
1930 direct access method and falls back to the BIOS if that doesn't
1931 work. If unsure, go with the default, which is "Any".
1936 config PCI_GOMMCONFIG
1953 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1955 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1958 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1962 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1966 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1970 depends on PCI && XEN
1978 bool "Support mmconfig PCI config space access"
1979 depends on X86_64 && PCI && ACPI
1981 config PCI_CNB20LE_QUIRK
1982 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1983 depends on PCI && EXPERIMENTAL
1985 Read the PCI windows out of the CNB20LE host bridge. This allows
1986 PCI hotplug to work on systems with the CNB20LE chipset which do
1989 There's no public spec for this chipset, and this functionality
1990 is known to be incomplete.
1992 You should say N unless you know you need this.
1994 source "drivers/pci/pcie/Kconfig"
1996 source "drivers/pci/Kconfig"
1998 # x86_64 have no ISA slots, but can have ISA-style DMA.
2000 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2003 Enables ISA-style DMA support for devices requiring such controllers.
2011 Find out whether you have ISA slots on your motherboard. ISA is the
2012 name of a bus system, i.e. the way the CPU talks to the other stuff
2013 inside your box. Other bus systems are PCI, EISA, MicroChannel
2014 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2015 newer boards don't support it. If you have ISA, say Y, otherwise N.
2021 The Extended Industry Standard Architecture (EISA) bus was
2022 developed as an open alternative to the IBM MicroChannel bus.
2024 The EISA bus provided some of the features of the IBM MicroChannel
2025 bus while maintaining backward compatibility with cards made for
2026 the older ISA bus. The EISA bus saw limited use between 1988 and
2027 1995 when it was made obsolete by the PCI bus.
2029 Say Y here if you are building a kernel for an EISA-based machine.
2033 source "drivers/eisa/Kconfig"
2036 tristate "NatSemi SCx200 support"
2038 This provides basic support for National Semiconductor's
2039 (now AMD's) Geode processors. The driver probes for the
2040 PCI-IDs of several on-chip devices, so its a good dependency
2041 for other scx200_* drivers.
2043 If compiled as a module, the driver is named scx200.
2045 config SCx200HR_TIMER
2046 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2050 This driver provides a clocksource built upon the on-chip
2051 27MHz high-resolution timer. Its also a workaround for
2052 NSC Geode SC-1100's buggy TSC, which loses time when the
2053 processor goes idle (as is done by the scheduler). The
2054 other workaround is idle=poll boot option.
2057 bool "One Laptop Per Child support"
2064 Add support for detecting the unique features of the OLPC
2068 bool "OLPC XO-1 Power Management"
2069 depends on OLPC && MFD_CS5535 && PM_SLEEP
2072 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2075 bool "OLPC XO-1 Real Time Clock"
2076 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2078 Add support for the XO-1 real time clock, which can be used as a
2079 programmable wakeup source.
2082 bool "OLPC XO-1 SCI extras"
2083 depends on OLPC && OLPC_XO1_PM
2088 Add support for SCI-based features of the OLPC XO-1 laptop:
2089 - EC-driven system wakeups
2093 - AC adapter status updates
2094 - Battery status updates
2096 config OLPC_XO15_SCI
2097 bool "OLPC XO-1.5 SCI extras"
2098 depends on OLPC && ACPI
2101 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2102 - EC-driven system wakeups
2103 - AC adapter status updates
2104 - Battery status updates
2107 bool "PCEngines ALIX System Support (LED setup)"
2110 This option enables system support for the PCEngines ALIX.
2111 At present this just sets up LEDs for GPIO control on
2112 ALIX2/3/6 boards. However, other system specific setup should
2115 Note: You must still enable the drivers for GPIO and LED support
2116 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2118 Note: You have to set alix.force=1 for boards with Award BIOS.
2121 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2124 This option enables system support for the Soekris Engineering net5501.
2127 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2131 This option enables system support for the Traverse Technologies GEOS.
2137 depends on CPU_SUP_AMD && PCI
2139 source "drivers/pcmcia/Kconfig"
2141 source "drivers/pci/hotplug/Kconfig"
2144 bool "RapidIO support"
2148 If you say Y here, the kernel will include drivers and
2149 infrastructure code to support RapidIO interconnect devices.
2151 source "drivers/rapidio/Kconfig"
2156 menu "Executable file formats / Emulations"
2158 source "fs/Kconfig.binfmt"
2160 config IA32_EMULATION
2161 bool "IA32 Emulation"
2163 select COMPAT_BINFMT_ELF
2165 Include code to run legacy 32-bit programs under a
2166 64-bit kernel. You should likely turn this on, unless you're
2167 100% sure that you don't have any 32-bit programs left.
2170 tristate "IA32 a.out support"
2171 depends on IA32_EMULATION
2173 Support old a.out binaries in the 32bit emulation.
2176 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2177 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2179 Include code to run binaries for the x32 native 32-bit ABI
2180 for 64-bit processors. An x32 process gets access to the
2181 full 64-bit register file and wide data path while leaving
2182 pointers at 32 bits for smaller memory footprint.
2184 You will need a recent binutils (2.22 or later) with
2185 elf32_x86_64 support enabled to compile a kernel with this
2190 depends on IA32_EMULATION || X86_X32
2191 select ARCH_WANT_OLD_COMPAT_IPC
2194 config COMPAT_FOR_U64_ALIGNMENT
2197 config SYSVIPC_COMPAT
2209 config HAVE_ATOMIC_IOMAP
2213 config HAVE_TEXT_POKE_SMP
2215 select STOP_MACHINE if SMP
2217 config X86_DEV_DMA_OPS
2219 depends on X86_64 || STA2X11
2221 config X86_DMA_REMAP
2225 source "net/Kconfig"
2227 source "drivers/Kconfig"
2229 source "drivers/firmware/Kconfig"
2233 source "arch/x86/Kconfig.debug"
2235 source "security/Kconfig"
2237 source "crypto/Kconfig"
2239 source "arch/x86/kvm/Kconfig"
2241 source "lib/Kconfig"