3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select X86_DEV_DMA_OPS
23 select HAVE_AOUT if X86_32
24 select HAVE_UNSTABLE_SCHED_CLOCK
25 select ARCH_SUPPORTS_NUMA_BALANCING
26 select ARCH_WANTS_PROT_NUMA_PROT_NONE
29 select HAVE_PCSPKR_PLATFORM
30 select HAVE_PERF_EVENTS
32 select HAVE_IOREMAP_PROT
35 select HAVE_MEMBLOCK_NODE_MAP
36 select ARCH_DISCARD_MEMBLOCK
37 select ARCH_WANT_OPTIONAL_GPIOLIB
38 select ARCH_WANT_FRAME_POINTERS
40 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
41 select HAVE_KRETPROBES
43 select HAVE_FTRACE_MCOUNT_RECORD
44 select HAVE_FENTRY if X86_64
45 select HAVE_C_RECORDMCOUNT
46 select HAVE_DYNAMIC_FTRACE
47 select HAVE_FUNCTION_TRACER
48 select HAVE_FUNCTION_GRAPH_TRACER
49 select HAVE_FUNCTION_GRAPH_FP_TEST
50 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
51 select HAVE_SYSCALL_TRACEPOINTS
52 select SYSCTL_EXCEPTION_TRACE
55 select HAVE_ARCH_TRACEHOOK
56 select HAVE_GENERIC_DMA_COHERENT if X86_32
57 select HAVE_EFFICIENT_UNALIGNED_ACCESS
58 select USER_STACKTRACE_SUPPORT
59 select HAVE_REGS_AND_STACK_ACCESS_API
60 select HAVE_DMA_API_DEBUG
61 select HAVE_KERNEL_GZIP
62 select HAVE_KERNEL_BZIP2
63 select HAVE_KERNEL_LZMA
65 select HAVE_KERNEL_LZO
66 select HAVE_HW_BREAKPOINT
67 select HAVE_MIXED_BREAKPOINTS_REGS
69 select HAVE_PERF_EVENTS_NMI
71 select HAVE_PERF_USER_STACK_DUMP
72 select HAVE_DEBUG_KMEMLEAK
74 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
75 select HAVE_CMPXCHG_LOCAL
76 select HAVE_CMPXCHG_DOUBLE
77 select HAVE_ARCH_KMEMCHECK
78 select HAVE_USER_RETURN_NOTIFIER
79 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
80 select HAVE_ARCH_JUMP_LABEL
81 select HAVE_TEXT_POKE_SMP
82 select HAVE_GENERIC_HARDIRQS
83 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
85 select GENERIC_FIND_FIRST_BIT
86 select GENERIC_IRQ_PROBE
87 select GENERIC_PENDING_IRQ if SMP
88 select GENERIC_IRQ_SHOW
89 select GENERIC_CLOCKEVENTS_MIN_ADJUST
90 select IRQ_FORCED_THREADING
91 select USE_GENERIC_SMP_HELPERS if SMP
92 select HAVE_BPF_JIT if X86_64
93 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
95 select ARCH_HAVE_NMI_SAFE_CMPXCHG
97 select DCACHE_WORD_ACCESS
98 select GENERIC_SMP_IDLE_THREAD
99 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
100 select HAVE_ARCH_SECCOMP_FILTER
101 select BUILDTIME_EXTABLE_SORT
102 select GENERIC_CMOS_UPDATE
103 select CLOCKSOURCE_WATCHDOG
104 select GENERIC_CLOCKEVENTS
105 select ARCH_CLOCKSOURCE_DATA if X86_64
106 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
107 select GENERIC_TIME_VSYSCALL if X86_64
108 select KTIME_SCALAR if X86_32
109 select GENERIC_STRNCPY_FROM_USER
110 select GENERIC_STRNLEN_USER
111 select HAVE_CONTEXT_TRACKING if X86_64
112 select HAVE_IRQ_TIME_ACCOUNTING
113 select GENERIC_KERNEL_THREAD
114 select GENERIC_KERNEL_EXECVE
115 select MODULES_USE_ELF_REL if X86_32
116 select MODULES_USE_ELF_RELA if X86_64
117 select CLONE_BACKWARDS if X86_32
119 config INSTRUCTION_DECODER
121 depends on KPROBES || PERF_EVENTS || UPROBES
125 default "elf32-i386" if X86_32
126 default "elf64-x86-64" if X86_64
128 config ARCH_DEFCONFIG
130 default "arch/x86/configs/i386_defconfig" if X86_32
131 default "arch/x86/configs/x86_64_defconfig" if X86_64
133 config LOCKDEP_SUPPORT
136 config STACKTRACE_SUPPORT
139 config HAVE_LATENCYTOP_SUPPORT
148 config NEED_DMA_MAP_STATE
150 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
152 config NEED_SG_DMA_LENGTH
155 config GENERIC_ISA_DMA
157 depends on ISA_DMA_API
162 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
164 config GENERIC_BUG_RELATIVE_POINTERS
167 config GENERIC_HWEIGHT
173 config ARCH_MAY_HAVE_PC_FDC
175 depends on ISA_DMA_API
177 config RWSEM_XCHGADD_ALGORITHM
180 config GENERIC_CALIBRATE_DELAY
183 config ARCH_HAS_CPU_RELAX
186 config ARCH_HAS_DEFAULT_IDLE
189 config ARCH_HAS_CACHE_LINE_SIZE
192 config ARCH_HAS_CPU_AUTOPROBE
195 config HAVE_SETUP_PER_CPU_AREA
198 config NEED_PER_CPU_EMBED_FIRST_CHUNK
201 config NEED_PER_CPU_PAGE_FIRST_CHUNK
204 config ARCH_HIBERNATION_POSSIBLE
207 config ARCH_SUSPEND_POSSIBLE
218 config ARCH_SUPPORTS_OPTIMIZED_INLINING
221 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
224 config HAVE_INTEL_TXT
226 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
230 depends on X86_32 && SMP
234 depends on X86_64 && SMP
240 config X86_32_LAZY_GS
242 depends on X86_32 && !CC_STACKPROTECTOR
244 config ARCH_HWEIGHT_CFLAGS
246 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
247 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
249 config ARCH_CPU_PROBE_RELEASE
251 depends on HOTPLUG_CPU
253 config ARCH_SUPPORTS_UPROBES
256 source "init/Kconfig"
257 source "kernel/Kconfig.freezer"
259 menu "Processor type and features"
262 bool "DMA memory allocation support" if EXPERT
265 DMA memory allocation support allows devices with less than 32-bit
266 addressing to allocate within the first 16MB of address space.
267 Disable if no such devices will be used.
272 bool "Symmetric multi-processing support"
274 This enables support for systems with more than one CPU. If you have
275 a system with only one CPU, like most personal computers, say N. If
276 you have a system with more than one CPU, say Y.
278 If you say N here, the kernel will run on single and multiprocessor
279 machines, but will use only one CPU of a multiprocessor machine. If
280 you say Y here, the kernel will run on many, but not all,
281 singleprocessor machines. On a singleprocessor machine, the kernel
282 will run faster if you say N here.
284 Note that if you say Y here and choose architecture "586" or
285 "Pentium" under "Processor family", the kernel will not work on 486
286 architectures. Similarly, multiprocessor kernels for the "PPro"
287 architecture may not work on all Pentium based boards.
289 People using multiprocessor machines who say Y here should also say
290 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
291 Management" code will be disabled if you say Y here.
293 See also <file:Documentation/x86/i386/IO-APIC.txt>,
294 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
295 <http://www.tldp.org/docs.html#howto>.
297 If you don't know what to do here, say N.
300 bool "Support x2apic"
301 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
303 This enables x2apic support on CPUs that have this feature.
305 This allows 32-bit apic IDs (so it can support very large systems),
306 and accesses the local apic via MSRs not via mmio.
308 If you don't know what to do here, say N.
311 bool "Enable MPS table" if ACPI || SFI
313 depends on X86_LOCAL_APIC
315 For old smp systems that do not have proper acpi support. Newer systems
316 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
319 bool "Support for big SMP systems with more than 8 CPUs"
320 depends on X86_32 && SMP
322 This option is needed for the systems that have more than 8 CPUs
325 config X86_EXTENDED_PLATFORM
326 bool "Support for extended (non-PC) x86 platforms"
329 If you disable this option then the kernel will only support
330 standard PC platforms. (which covers the vast majority of
333 If you enable this option then you'll be able to select support
334 for the following (non-PC) 32 bit x86 platforms:
338 SGI 320/540 (Visual Workstation)
339 STA2X11-based (e.g. Northville)
340 Summit/EXA (IBM x440)
341 Unisys ES7000 IA32 series
342 Moorestown MID devices
344 If you have one of these systems, or if you want to build a
345 generic distribution kernel, say Y here - otherwise say N.
349 config X86_EXTENDED_PLATFORM
350 bool "Support for extended (non-PC) x86 platforms"
353 If you disable this option then the kernel will only support
354 standard PC platforms. (which covers the vast majority of
357 If you enable this option then you'll be able to select support
358 for the following (non-PC) 64 bit x86 platforms:
363 If you have one of these systems, or if you want to build a
364 generic distribution kernel, say Y here - otherwise say N.
366 # This is an alphabetically sorted list of 64 bit extended platforms
367 # Please maintain the alphabetic order if and when there are additions
369 bool "Numascale NumaChip"
371 depends on X86_EXTENDED_PLATFORM
374 depends on X86_X2APIC
375 depends on PCI_MMCONFIG
377 Adds support for Numascale NumaChip large-SMP systems. Needed to
378 enable more than ~168 cores.
379 If you don't have one of these, you should say N here.
383 select PARAVIRT_GUEST
385 depends on X86_64 && PCI
386 depends on X86_EXTENDED_PLATFORM
389 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
390 supposed to run on these EM64T-based machines. Only choose this option
391 if you have one of these machines.
394 bool "SGI Ultraviolet"
396 depends on X86_EXTENDED_PLATFORM
398 depends on X86_X2APIC
400 This option is needed in order to support SGI Ultraviolet systems.
401 If you don't have one of these, you should say N here.
403 # Following is an alphabetically sorted list of 32 bit extended platforms
404 # Please maintain the alphabetic order if and when there are additions
407 bool "CE4100 TV platform"
409 depends on PCI_GODIRECT
411 depends on X86_EXTENDED_PLATFORM
412 select X86_REBOOTFIXUPS
414 select OF_EARLY_FLATTREE
417 Select for the Intel CE media processor (CE4100) SOC.
418 This option compiles in support for the CE4100 SOC for settop
419 boxes and media devices.
421 config X86_WANT_INTEL_MID
422 bool "Intel MID platform support"
424 depends on X86_EXTENDED_PLATFORM
426 Select to build a kernel capable of supporting Intel MID platform
427 systems which do not have the PCI legacy interfaces (Moorestown,
428 Medfield). If you are building for a PC class system say N here.
430 if X86_WANT_INTEL_MID
436 bool "Medfield MID platform"
439 depends on X86_IO_APIC
447 select X86_PLATFORM_DEVICES
448 select MFD_INTEL_MSIC
450 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
451 Internet Device(MID) platform.
452 Unlike standard x86 PCs, Medfield does not have many legacy devices
453 nor standard legacy replacement devices/features. e.g. Medfield does
454 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
459 bool "RDC R-321x SoC"
461 depends on X86_EXTENDED_PLATFORM
463 select X86_REBOOTFIXUPS
465 This option is needed for RDC R-321x system-on-chip, also known
467 If you don't have one of these chips, you should say N here.
469 config X86_32_NON_STANDARD
470 bool "Support non-standard 32-bit SMP architectures"
471 depends on X86_32 && SMP
472 depends on X86_EXTENDED_PLATFORM
474 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
475 STA2X11, default subarchitectures. It is intended for a generic
476 binary kernel. If you select them all, kernel will probe it
477 one by one and will fallback to default.
479 # Alphabetically sorted list of Non standard 32 bit platforms
482 bool "NUMAQ (IBM/Sequent)"
483 depends on X86_32_NON_STANDARD
488 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
489 NUMA multiquad box. This changes the way that processors are
490 bootstrapped, and uses Clustered Logical APIC addressing mode instead
491 of Flat Logical. You will need a new lynxer.elf file to flash your
492 firmware with - send email to <Martin.Bligh@us.ibm.com>.
494 config X86_SUPPORTS_MEMORY_FAILURE
496 # MCE code calls memory_failure():
498 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
499 depends on !X86_NUMAQ
500 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
501 depends on X86_64 || !SPARSEMEM
502 select ARCH_SUPPORTS_MEMORY_FAILURE
505 bool "SGI 320/540 (Visual Workstation)"
506 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
507 depends on X86_32_NON_STANDARD
509 The SGI Visual Workstation series is an IA32-based workstation
510 based on SGI systems chips with some legacy PC hardware attached.
512 Say Y here to create a kernel to run on the SGI 320 or 540.
514 A kernel compiled for the Visual Workstation will run on general
515 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
518 bool "STA2X11 Companion Chip Support"
519 depends on X86_32_NON_STANDARD && PCI
520 select X86_DEV_DMA_OPS
524 select ARCH_REQUIRE_GPIOLIB
527 This adds support for boards based on the STA2X11 IO-Hub,
528 a.k.a. "ConneXt". The chip is used in place of the standard
529 PC chipset, so all "standard" peripherals are missing. If this
530 option is selected the kernel will still be able to boot on
531 standard PC machines.
534 bool "Summit/EXA (IBM x440)"
535 depends on X86_32_NON_STANDARD
537 This option is needed for IBM systems that use the Summit/EXA chipset.
538 In particular, it is needed for the x440.
541 bool "Unisys ES7000 IA32 series"
542 depends on X86_32_NON_STANDARD && X86_BIGSMP
544 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
545 supposed to run on an IA32-based Unisys ES7000 system.
548 tristate "Eurobraille/Iris poweroff module"
551 The Iris machines from EuroBraille do not have APM or ACPI support
552 to shut themselves down properly. A special I/O sequence is
553 needed to do so, which is what this module does at
556 This is only for Iris machines from EuroBraille.
560 config SCHED_OMIT_FRAME_POINTER
562 prompt "Single-depth WCHAN output"
565 Calculate simpler /proc/<PID>/wchan values. If this option
566 is disabled then wchan values will recurse back to the
567 caller function. This provides more accurate wchan values,
568 at the expense of slightly more scheduling overhead.
570 If in doubt, say "Y".
572 menuconfig PARAVIRT_GUEST
573 bool "Paravirtualized guest support"
575 Say Y here to get to see options related to running Linux under
576 various hypervisors. This option alone does not add any kernel code.
578 If you say N, all options in this submenu will be skipped and disabled.
582 config PARAVIRT_TIME_ACCOUNTING
583 bool "Paravirtual steal time accounting"
587 Select this option to enable fine granularity task steal time
588 accounting. Time spent executing other tasks in parallel with
589 the current vCPU is discounted from the vCPU power. To account for
590 that, there can be a small performance impact.
592 If in doubt, say N here.
594 source "arch/x86/xen/Kconfig"
597 bool "KVM Guest support (including kvmclock)"
600 select PARAVIRT_CLOCK
601 default y if PARAVIRT_GUEST
603 This option enables various optimizations for running under the KVM
604 hypervisor. It includes a paravirtualized clock, so that instead
605 of relying on a PIT (or probably other) emulation by the
606 underlying device model, the host provides the guest with
607 timing infrastructure such as time of day, and system time
609 source "arch/x86/lguest/Kconfig"
612 bool "Enable paravirtualization code"
614 This changes the kernel so it can modify itself when it is run
615 under a hypervisor, potentially improving performance significantly
616 over full virtualization. However, when run without a hypervisor
617 the kernel is theoretically slower and slightly larger.
619 config PARAVIRT_SPINLOCKS
620 bool "Paravirtualization layer for spinlocks"
621 depends on PARAVIRT && SMP && EXPERIMENTAL
623 Paravirtualized spinlocks allow a pvops backend to replace the
624 spinlock implementation with something virtualization-friendly
625 (for example, block the virtual CPU rather than spinning).
627 Unfortunately the downside is an up to 5% performance hit on
628 native kernels, with various workloads.
630 If you are unsure how to answer this question, answer N.
632 config PARAVIRT_CLOCK
637 config PARAVIRT_DEBUG
638 bool "paravirt-ops debugging"
639 depends on PARAVIRT && DEBUG_KERNEL
641 Enable to debug paravirt_ops internals. Specifically, BUG if
642 a paravirt_op is missing when it is called.
650 This option adds a kernel parameter 'memtest', which allows memtest
652 memtest=0, mean disabled; -- default
653 memtest=1, mean do 1 test pattern;
655 memtest=4, mean do 4 test patterns.
656 If you are unsure how to answer this question, answer N.
658 config X86_SUMMIT_NUMA
660 depends on X86_32 && NUMA && X86_32_NON_STANDARD
662 config X86_CYCLONE_TIMER
664 depends on X86_SUMMIT
666 source "arch/x86/Kconfig.cpu"
670 prompt "HPET Timer Support" if X86_32
672 Use the IA-PC HPET (High Precision Event Timer) to manage
673 time in preference to the PIT and RTC, if a HPET is
675 HPET is the next generation timer replacing legacy 8254s.
676 The HPET provides a stable time base on SMP
677 systems, unlike the TSC, but it is more expensive to access,
678 as it is off-chip. You can find the HPET spec at
679 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
681 You can safely choose Y here. However, HPET will only be
682 activated if the platform and the BIOS support this feature.
683 Otherwise the 8254 will be used for timing services.
685 Choose N to continue using the legacy 8254 timer.
687 config HPET_EMULATE_RTC
689 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
692 def_bool y if X86_INTEL_MID
693 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
695 depends on X86_INTEL_MID && SFI
697 APB timer is the replacement for 8254, HPET on X86 MID platforms.
698 The APBT provides a stable time base on SMP
699 systems, unlike the TSC, but it is more expensive to access,
700 as it is off-chip. APB timers are always running regardless of CPU
701 C states, they are used as per CPU clockevent device when possible.
703 # Mark as expert because too many people got it wrong.
704 # The code disables itself when not needed.
707 bool "Enable DMI scanning" if EXPERT
709 Enabled scanning of DMI to identify machine quirks. Say Y
710 here unless you have verified that your setup is not
711 affected by entries in the DMI blacklist. Required by PNP
715 bool "GART IOMMU support" if EXPERT
718 depends on X86_64 && PCI && AMD_NB
720 Support for full DMA access of devices with 32bit memory access only
721 on systems with more than 3GB. This is usually needed for USB,
722 sound, many IDE/SATA chipsets and some other devices.
723 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
724 based hardware IOMMU and a software bounce buffer based IOMMU used
725 on Intel systems and as fallback.
726 The code is only active when needed (enough memory and limited
727 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
731 bool "IBM Calgary IOMMU support"
733 depends on X86_64 && PCI && EXPERIMENTAL
735 Support for hardware IOMMUs in IBM's xSeries x366 and x460
736 systems. Needed to run systems with more than 3GB of memory
737 properly with 32-bit PCI devices that do not support DAC
738 (Double Address Cycle). Calgary also supports bus level
739 isolation, where all DMAs pass through the IOMMU. This
740 prevents them from going anywhere except their intended
741 destination. This catches hard-to-find kernel bugs and
742 mis-behaving drivers and devices that do not use the DMA-API
743 properly to set up their DMA buffers. The IOMMU can be
744 turned off at boot time with the iommu=off parameter.
745 Normally the kernel will make the right choice by itself.
748 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
750 prompt "Should Calgary be enabled by default?"
751 depends on CALGARY_IOMMU
753 Should Calgary be enabled by default? if you choose 'y', Calgary
754 will be used (if it exists). If you choose 'n', Calgary will not be
755 used even if it exists. If you choose 'n' and would like to use
756 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
759 # need this always selected by IOMMU for the VIA workaround
763 Support for software bounce buffers used on x86-64 systems
764 which don't have a hardware IOMMU. Using this PCI devices
765 which can only access 32-bits of memory can be used on systems
766 with more than 3 GB of memory.
771 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
774 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
775 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
776 select CPUMASK_OFFSTACK
778 Enable maximum number of CPUS and NUMA Nodes for this architecture.
782 int "Maximum number of CPUs" if SMP && !MAXSMP
783 range 2 8 if SMP && X86_32 && !X86_BIGSMP
784 range 2 512 if SMP && !MAXSMP
786 default "4096" if MAXSMP
787 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
790 This allows you to specify the maximum number of CPUs which this
791 kernel will support. The maximum supported value is 512 and the
792 minimum value which makes sense is 2.
794 This is purely to save memory - each supported CPU adds
795 approximately eight kilobytes to the kernel image.
798 bool "SMT (Hyperthreading) scheduler support"
801 SMT scheduler support improves the CPU scheduler's decision making
802 when dealing with Intel Pentium 4 chips with HyperThreading at a
803 cost of slightly increased overhead in some places. If unsure say
808 prompt "Multi-core scheduler support"
811 Multi-core scheduler support improves the CPU scheduler's decision
812 making when dealing with multi-core CPU chips at a cost of slightly
813 increased overhead in some places. If unsure say N here.
815 source "kernel/Kconfig.preempt"
818 bool "Local APIC support on uniprocessors"
819 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
821 A local APIC (Advanced Programmable Interrupt Controller) is an
822 integrated interrupt controller in the CPU. If you have a single-CPU
823 system which has a processor with a local APIC, you can say Y here to
824 enable and use it. If you say Y here even though your machine doesn't
825 have a local APIC, then the kernel will still run with no slowdown at
826 all. The local APIC supports CPU-generated self-interrupts (timer,
827 performance counters), and the NMI watchdog which detects hard
831 bool "IO-APIC support on uniprocessors"
832 depends on X86_UP_APIC
834 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
835 SMP-capable replacement for PC-style interrupt controllers. Most
836 SMP systems and many recent uniprocessor systems have one.
838 If you have a single-CPU system with an IO-APIC, you can say Y here
839 to use it. If you say Y here even though your machine doesn't have
840 an IO-APIC, then the kernel will still run with no slowdown at all.
842 config X86_LOCAL_APIC
844 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
848 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
850 config X86_VISWS_APIC
852 depends on X86_32 && X86_VISWS
854 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
855 bool "Reroute for broken boot IRQs"
856 depends on X86_IO_APIC
858 This option enables a workaround that fixes a source of
859 spurious interrupts. This is recommended when threaded
860 interrupt handling is used on systems where the generation of
861 superfluous "boot interrupts" cannot be disabled.
863 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
864 entry in the chipset's IO-APIC is masked (as, e.g. the RT
865 kernel does during interrupt handling). On chipsets where this
866 boot IRQ generation cannot be disabled, this workaround keeps
867 the original IRQ line masked so that only the equivalent "boot
868 IRQ" is delivered to the CPUs. The workaround also tells the
869 kernel to set up the IRQ handler on the boot IRQ line. In this
870 way only one interrupt is delivered to the kernel. Otherwise
871 the spurious second interrupt may cause the kernel to bring
872 down (vital) interrupt lines.
874 Only affects "broken" chipsets. Interrupt sharing may be
875 increased on these systems.
878 bool "Machine Check / overheating reporting"
881 Machine Check support allows the processor to notify the
882 kernel if it detects a problem (e.g. overheating, data corruption).
883 The action the kernel takes depends on the severity of the problem,
884 ranging from warning messages to halting the machine.
888 prompt "Intel MCE features"
889 depends on X86_MCE && X86_LOCAL_APIC
891 Additional support for intel specific MCE features such as
896 prompt "AMD MCE features"
897 depends on X86_MCE && X86_LOCAL_APIC
899 Additional support for AMD specific MCE features such as
900 the DRAM Error Threshold.
902 config X86_ANCIENT_MCE
903 bool "Support for old Pentium 5 / WinChip machine checks"
904 depends on X86_32 && X86_MCE
906 Include support for machine check handling on old Pentium 5 or WinChip
907 systems. These typically need to be enabled explicitely on the command
910 config X86_MCE_THRESHOLD
911 depends on X86_MCE_AMD || X86_MCE_INTEL
914 config X86_MCE_INJECT
916 tristate "Machine check injector support"
918 Provide support for injecting machine checks for testing purposes.
919 If you don't know what a machine check is and you don't do kernel
920 QA it is safe to say n.
922 config X86_THERMAL_VECTOR
924 depends on X86_MCE_INTEL
927 bool "Enable VM86 support" if EXPERT
931 This option is required by programs like DOSEMU to run 16-bit legacy
932 code on X86 processors. It also may be needed by software like
933 XFree86 to initialize some video cards via BIOS. Disabling this
934 option saves about 6k.
937 tristate "Toshiba Laptop support"
940 This adds a driver to safely access the System Management Mode of
941 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
942 not work on models with a Phoenix BIOS. The System Management Mode
943 is used to set the BIOS and power saving options on Toshiba portables.
945 For information on utilities to make use of this driver see the
946 Toshiba Linux utilities web site at:
947 <http://www.buzzard.org.uk/toshiba/>.
949 Say Y if you intend to run this kernel on a Toshiba portable.
953 tristate "Dell laptop support"
956 This adds a driver to safely access the System Management Mode
957 of the CPU on the Dell Inspiron 8000. The System Management Mode
958 is used to read cpu temperature and cooling fan status and to
959 control the fans on the I8K portables.
961 This driver has been tested only on the Inspiron 8000 but it may
962 also work with other Dell laptops. You can force loading on other
963 models by passing the parameter `force=1' to the module. Use at
966 For information on utilities to make use of this driver see the
967 I8K Linux utilities web site at:
968 <http://people.debian.org/~dz/i8k/>
970 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
973 config X86_REBOOTFIXUPS
974 bool "Enable X86 board specific fixups for reboot"
977 This enables chipset and/or board specific fixups to be done
978 in order to get reboot to work correctly. This is only needed on
979 some combinations of hardware and BIOS. The symptom, for which
980 this config is intended, is when reboot ends with a stalled/hung
983 Currently, the only fixup is for the Geode machines using
984 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
986 Say Y if you want to enable the fixup. Currently, it's safe to
987 enable this option even if you don't need it.
991 tristate "CPU microcode loading support"
995 If you say Y here, you will be able to update the microcode on
996 certain Intel and AMD processors. The Intel support is for the
997 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
998 Xeon etc. The AMD support is for families 0x10 and later. You will
999 obviously need the actual microcode binary data itself which is not
1000 shipped with the Linux kernel.
1002 This option selects the general module only, you need to select
1003 at least one vendor specific module as well.
1005 To compile this driver as a module, choose M here: the module
1006 will be called microcode.
1008 config MICROCODE_INTEL
1009 bool "Intel microcode loading support"
1010 depends on MICROCODE
1014 This options enables microcode patch loading support for Intel
1017 For latest news and information on obtaining all the required
1018 Intel ingredients for this driver, check:
1019 <http://www.urbanmyth.org/microcode/>.
1021 config MICROCODE_AMD
1022 bool "AMD microcode loading support"
1023 depends on MICROCODE
1026 If you select this option, microcode patch loading support for AMD
1027 processors will be enabled.
1029 config MICROCODE_OLD_INTERFACE
1031 depends on MICROCODE
1034 tristate "/dev/cpu/*/msr - Model-specific register support"
1036 This device gives privileged processes access to the x86
1037 Model-Specific Registers (MSRs). It is a character device with
1038 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1039 MSR accesses are directed to a specific CPU on multi-processor
1043 tristate "/dev/cpu/*/cpuid - CPU information support"
1045 This device gives processes access to the x86 CPUID instruction to
1046 be executed on a specific processor. It is a character device
1047 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1051 prompt "High Memory Support"
1052 default HIGHMEM64G if X86_NUMAQ
1058 depends on !X86_NUMAQ
1060 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1061 However, the address space of 32-bit x86 processors is only 4
1062 Gigabytes large. That means that, if you have a large amount of
1063 physical memory, not all of it can be "permanently mapped" by the
1064 kernel. The physical memory that's not permanently mapped is called
1067 If you are compiling a kernel which will never run on a machine with
1068 more than 1 Gigabyte total physical RAM, answer "off" here (default
1069 choice and suitable for most users). This will result in a "3GB/1GB"
1070 split: 3GB are mapped so that each process sees a 3GB virtual memory
1071 space and the remaining part of the 4GB virtual memory space is used
1072 by the kernel to permanently map as much physical memory as
1075 If the machine has between 1 and 4 Gigabytes physical RAM, then
1078 If more than 4 Gigabytes is used then answer "64GB" here. This
1079 selection turns Intel PAE (Physical Address Extension) mode on.
1080 PAE implements 3-level paging on IA32 processors. PAE is fully
1081 supported by Linux, PAE mode is implemented on all recent Intel
1082 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1083 then the kernel will not boot on CPUs that don't support PAE!
1085 The actual amount of total physical memory will either be
1086 auto detected or can be forced by using a kernel command line option
1087 such as "mem=256M". (Try "man bootparam" or see the documentation of
1088 your boot loader (lilo or loadlin) about how to pass options to the
1089 kernel at boot time.)
1091 If unsure, say "off".
1095 depends on !X86_NUMAQ
1097 Select this if you have a 32-bit processor and between 1 and 4
1098 gigabytes of physical RAM.
1105 Select this if you have a 32-bit processor and more than 4
1106 gigabytes of physical RAM.
1111 depends on EXPERIMENTAL
1112 prompt "Memory split" if EXPERT
1116 Select the desired split between kernel and user memory.
1118 If the address range available to the kernel is less than the
1119 physical memory installed, the remaining memory will be available
1120 as "high memory". Accessing high memory is a little more costly
1121 than low memory, as it needs to be mapped into the kernel first.
1122 Note that increasing the kernel address space limits the range
1123 available to user programs, making the address space there
1124 tighter. Selecting anything other than the default 3G/1G split
1125 will also likely make your kernel incompatible with binary-only
1128 If you are not absolutely sure what you are doing, leave this
1132 bool "3G/1G user/kernel split"
1133 config VMSPLIT_3G_OPT
1135 bool "3G/1G user/kernel split (for full 1G low memory)"
1137 bool "2G/2G user/kernel split"
1138 config VMSPLIT_2G_OPT
1140 bool "2G/2G user/kernel split (for full 2G low memory)"
1142 bool "1G/3G user/kernel split"
1147 default 0xB0000000 if VMSPLIT_3G_OPT
1148 default 0x80000000 if VMSPLIT_2G
1149 default 0x78000000 if VMSPLIT_2G_OPT
1150 default 0x40000000 if VMSPLIT_1G
1156 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1159 bool "PAE (Physical Address Extension) Support"
1160 depends on X86_32 && !HIGHMEM4G
1162 PAE is required for NX support, and furthermore enables
1163 larger swapspace support for non-overcommit purposes. It
1164 has the cost of more pagetable lookup overhead, and also
1165 consumes more pagetable space per process.
1167 config ARCH_PHYS_ADDR_T_64BIT
1169 depends on X86_64 || X86_PAE
1171 config ARCH_DMA_ADDR_T_64BIT
1173 depends on X86_64 || HIGHMEM64G
1175 config DIRECT_GBPAGES
1176 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1180 Allow the kernel linear mapping to use 1GB pages on CPUs that
1181 support it. This can improve the kernel's performance a tiny bit by
1182 reducing TLB pressure. If in doubt, say "Y".
1184 # Common NUMA Features
1186 bool "Numa Memory Allocation and Scheduler Support"
1188 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1189 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1191 Enable NUMA (Non Uniform Memory Access) support.
1193 The kernel will try to allocate memory used by a CPU on the
1194 local memory controller of the CPU and add some more
1195 NUMA awareness to the kernel.
1197 For 64-bit this is recommended if the system is Intel Core i7
1198 (or later), AMD Opteron, or EM64T NUMA.
1200 For 32-bit this is only needed on (rare) 32-bit-only platforms
1201 that support NUMA topologies, such as NUMAQ / Summit, or if you
1202 boot a 32-bit kernel on a 64-bit NUMA platform.
1204 Otherwise, you should say N.
1206 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1207 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1211 prompt "Old style AMD Opteron NUMA detection"
1212 depends on X86_64 && NUMA && PCI
1214 Enable AMD NUMA node topology detection. You should say Y here if
1215 you have a multi processor AMD system. This uses an old method to
1216 read the NUMA configuration directly from the builtin Northbridge
1217 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1218 which also takes priority if both are compiled in.
1220 config X86_64_ACPI_NUMA
1222 prompt "ACPI NUMA detection"
1223 depends on X86_64 && NUMA && ACPI && PCI
1226 Enable ACPI SRAT based node topology detection.
1228 # Some NUMA nodes have memory ranges that span
1229 # other nodes. Even though a pfn is valid and
1230 # between a node's start and end pfns, it may not
1231 # reside on that node. See memmap_init_zone()
1233 config NODES_SPAN_OTHER_NODES
1235 depends on X86_64_ACPI_NUMA
1238 bool "NUMA emulation"
1241 Enable NUMA emulation. A flat machine will be split
1242 into virtual nodes when booted with "numa=fake=N", where N is the
1243 number of nodes. This is only useful for debugging.
1246 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1248 default "10" if MAXSMP
1249 default "6" if X86_64
1250 default "4" if X86_NUMAQ
1252 depends on NEED_MULTIPLE_NODES
1254 Specify the maximum number of NUMA Nodes available on the target
1255 system. Increases memory reserved to accommodate various tables.
1257 config HAVE_ARCH_ALLOC_REMAP
1259 depends on X86_32 && NUMA
1261 config ARCH_HAVE_MEMORY_PRESENT
1263 depends on X86_32 && DISCONTIGMEM
1265 config NEED_NODE_MEMMAP_SIZE
1267 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1269 config ARCH_FLATMEM_ENABLE
1271 depends on X86_32 && !NUMA
1273 config ARCH_DISCONTIGMEM_ENABLE
1275 depends on NUMA && X86_32
1277 config ARCH_DISCONTIGMEM_DEFAULT
1279 depends on NUMA && X86_32
1281 config ARCH_SPARSEMEM_ENABLE
1283 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1284 select SPARSEMEM_STATIC if X86_32
1285 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1287 config ARCH_SPARSEMEM_DEFAULT
1291 config ARCH_SELECT_MEMORY_MODEL
1293 depends on ARCH_SPARSEMEM_ENABLE
1295 config ARCH_MEMORY_PROBE
1297 depends on X86_64 && MEMORY_HOTPLUG
1299 config ARCH_PROC_KCORE_TEXT
1301 depends on X86_64 && PROC_KCORE
1303 config ILLEGAL_POINTER_VALUE
1306 default 0xdead000000000000 if X86_64
1311 bool "Allocate 3rd-level pagetables from highmem"
1314 The VM uses one page table entry for each page of physical memory.
1315 For systems with a lot of RAM, this can be wasteful of precious
1316 low memory. Setting this option will put user-space page table
1317 entries in high memory.
1319 config X86_CHECK_BIOS_CORRUPTION
1320 bool "Check for low memory corruption"
1322 Periodically check for memory corruption in low memory, which
1323 is suspected to be caused by BIOS. Even when enabled in the
1324 configuration, it is disabled at runtime. Enable it by
1325 setting "memory_corruption_check=1" on the kernel command
1326 line. By default it scans the low 64k of memory every 60
1327 seconds; see the memory_corruption_check_size and
1328 memory_corruption_check_period parameters in
1329 Documentation/kernel-parameters.txt to adjust this.
1331 When enabled with the default parameters, this option has
1332 almost no overhead, as it reserves a relatively small amount
1333 of memory and scans it infrequently. It both detects corruption
1334 and prevents it from affecting the running system.
1336 It is, however, intended as a diagnostic tool; if repeatable
1337 BIOS-originated corruption always affects the same memory,
1338 you can use memmap= to prevent the kernel from using that
1341 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1342 bool "Set the default setting of memory_corruption_check"
1343 depends on X86_CHECK_BIOS_CORRUPTION
1346 Set whether the default state of memory_corruption_check is
1349 config X86_RESERVE_LOW
1350 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1354 Specify the amount of low memory to reserve for the BIOS.
1356 The first page contains BIOS data structures that the kernel
1357 must not use, so that page must always be reserved.
1359 By default we reserve the first 64K of physical RAM, as a
1360 number of BIOSes are known to corrupt that memory range
1361 during events such as suspend/resume or monitor cable
1362 insertion, so it must not be used by the kernel.
1364 You can set this to 4 if you are absolutely sure that you
1365 trust the BIOS to get all its memory reservations and usages
1366 right. If you know your BIOS have problems beyond the
1367 default 64K area, you can set this to 640 to avoid using the
1368 entire low memory range.
1370 If you have doubts about the BIOS (e.g. suspend/resume does
1371 not work or there's kernel crashes after certain hardware
1372 hotplug events) then you might want to enable
1373 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1374 typical corruption patterns.
1376 Leave this to the default value of 64 if you are unsure.
1378 config MATH_EMULATION
1380 prompt "Math emulation" if X86_32
1382 Linux can emulate a math coprocessor (used for floating point
1383 operations) if you don't have one. 486DX and Pentium processors have
1384 a math coprocessor built in, 486SX and 386 do not, unless you added
1385 a 487DX or 387, respectively. (The messages during boot time can
1386 give you some hints here ["man dmesg"].) Everyone needs either a
1387 coprocessor or this emulation.
1389 If you don't have a math coprocessor, you need to say Y here; if you
1390 say Y here even though you have a coprocessor, the coprocessor will
1391 be used nevertheless. (This behavior can be changed with the kernel
1392 command line option "no387", which comes handy if your coprocessor
1393 is broken. Try "man bootparam" or see the documentation of your boot
1394 loader (lilo or loadlin) about how to pass options to the kernel at
1395 boot time.) This means that it is a good idea to say Y here if you
1396 intend to use this kernel on different machines.
1398 More information about the internals of the Linux math coprocessor
1399 emulation can be found in <file:arch/x86/math-emu/README>.
1401 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1402 kernel, it won't hurt.
1406 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1408 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1409 the Memory Type Range Registers (MTRRs) may be used to control
1410 processor access to memory ranges. This is most useful if you have
1411 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1412 allows bus write transfers to be combined into a larger transfer
1413 before bursting over the PCI/AGP bus. This can increase performance
1414 of image write operations 2.5 times or more. Saying Y here creates a
1415 /proc/mtrr file which may be used to manipulate your processor's
1416 MTRRs. Typically the X server should use this.
1418 This code has a reasonably generic interface so that similar
1419 control registers on other processors can be easily supported
1422 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1423 Registers (ARRs) which provide a similar functionality to MTRRs. For
1424 these, the ARRs are used to emulate the MTRRs.
1425 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1426 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1427 write-combining. All of these processors are supported by this code
1428 and it makes sense to say Y here if you have one of them.
1430 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1431 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1432 can lead to all sorts of problems, so it's good to say Y here.
1434 You can safely say Y even if your machine doesn't have MTRRs, you'll
1435 just add about 9 KB to your kernel.
1437 See <file:Documentation/x86/mtrr.txt> for more information.
1439 config MTRR_SANITIZER
1441 prompt "MTRR cleanup support"
1444 Convert MTRR layout from continuous to discrete, so X drivers can
1445 add writeback entries.
1447 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1448 The largest mtrr entry size for a continuous block can be set with
1453 config MTRR_SANITIZER_ENABLE_DEFAULT
1454 int "MTRR cleanup enable value (0-1)"
1457 depends on MTRR_SANITIZER
1459 Enable mtrr cleanup default value
1461 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1462 int "MTRR cleanup spare reg num (0-7)"
1465 depends on MTRR_SANITIZER
1467 mtrr cleanup spare entries default, it can be changed via
1468 mtrr_spare_reg_nr=N on the kernel command line.
1472 prompt "x86 PAT support" if EXPERT
1475 Use PAT attributes to setup page level cache control.
1477 PATs are the modern equivalents of MTRRs and are much more
1478 flexible than MTRRs.
1480 Say N here if you see bootup problems (boot crash, boot hang,
1481 spontaneous reboots) or a non-working video driver.
1485 config ARCH_USES_PG_UNCACHED
1491 prompt "x86 architectural random number generator" if EXPERT
1493 Enable the x86 architectural RDRAND instruction
1494 (Intel Bull Mountain technology) to generate random numbers.
1495 If supported, this is a high bandwidth, cryptographically
1496 secure hardware random number generator.
1500 prompt "Supervisor Mode Access Prevention" if EXPERT
1502 Supervisor Mode Access Prevention (SMAP) is a security
1503 feature in newer Intel processors. There is a small
1504 performance cost if this enabled and turned on; there is
1505 also a small increase in the kernel size if this is enabled.
1510 bool "EFI runtime service support"
1513 This enables the kernel to use EFI runtime services that are
1514 available (such as the EFI variable services).
1516 This option is only useful on systems that have EFI firmware.
1517 In addition, you should use the latest ELILO loader available
1518 at <http://elilo.sourceforge.net> in order to take advantage
1519 of EFI runtime services. However, even with this option, the
1520 resultant kernel should continue to boot on existing non-EFI
1524 bool "EFI stub support"
1527 This kernel feature allows a bzImage to be loaded directly
1528 by EFI firmware without the use of a bootloader.
1530 See Documentation/x86/efi-stub.txt for more information.
1534 prompt "Enable seccomp to safely compute untrusted bytecode"
1536 This kernel feature is useful for number crunching applications
1537 that may need to compute untrusted bytecode during their
1538 execution. By using pipes or other transports made available to
1539 the process as file descriptors supporting the read/write
1540 syscalls, it's possible to isolate those applications in
1541 their own address space using seccomp. Once seccomp is
1542 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1543 and the task is only allowed to execute a few safe syscalls
1544 defined by each seccomp mode.
1546 If unsure, say Y. Only embedded should say N here.
1548 config CC_STACKPROTECTOR
1549 bool "Enable -fstack-protector buffer overflow detection"
1551 This option turns on the -fstack-protector GCC feature. This
1552 feature puts, at the beginning of functions, a canary value on
1553 the stack just before the return address, and validates
1554 the value just before actually returning. Stack based buffer
1555 overflows (that need to overwrite this return address) now also
1556 overwrite the canary, which gets detected and the attack is then
1557 neutralized via a kernel panic.
1559 This feature requires gcc version 4.2 or above, or a distribution
1560 gcc with the feature backported. Older versions are automatically
1561 detected and for those versions, this configuration option is
1562 ignored. (and a warning is printed during bootup)
1564 source kernel/Kconfig.hz
1567 bool "kexec system call"
1569 kexec is a system call that implements the ability to shutdown your
1570 current kernel, and to start another kernel. It is like a reboot
1571 but it is independent of the system firmware. And like a reboot
1572 you can start any kernel with it, not just Linux.
1574 The name comes from the similarity to the exec system call.
1576 It is an ongoing process to be certain the hardware in a machine
1577 is properly shutdown, so do not be surprised if this code does not
1578 initially work for you. It may help to enable device hotplugging
1579 support. As of this writing the exact hardware interface is
1580 strongly in flux, so no good recommendation can be made.
1583 bool "kernel crash dumps"
1584 depends on X86_64 || (X86_32 && HIGHMEM)
1586 Generate crash dump after being started by kexec.
1587 This should be normally only set in special crash dump kernels
1588 which are loaded in the main kernel with kexec-tools into
1589 a specially reserved region and then later executed after
1590 a crash by kdump/kexec. The crash dump kernel must be compiled
1591 to a memory address not used by the main kernel or BIOS using
1592 PHYSICAL_START, or it must be built as a relocatable image
1593 (CONFIG_RELOCATABLE=y).
1594 For more details see Documentation/kdump/kdump.txt
1597 bool "kexec jump (EXPERIMENTAL)"
1598 depends on EXPERIMENTAL
1599 depends on KEXEC && HIBERNATION
1601 Jump between original kernel and kexeced kernel and invoke
1602 code in physical address mode via KEXEC
1604 config PHYSICAL_START
1605 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1608 This gives the physical address where the kernel is loaded.
1610 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1611 bzImage will decompress itself to above physical address and
1612 run from there. Otherwise, bzImage will run from the address where
1613 it has been loaded by the boot loader and will ignore above physical
1616 In normal kdump cases one does not have to set/change this option
1617 as now bzImage can be compiled as a completely relocatable image
1618 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1619 address. This option is mainly useful for the folks who don't want
1620 to use a bzImage for capturing the crash dump and want to use a
1621 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1622 to be specifically compiled to run from a specific memory area
1623 (normally a reserved region) and this option comes handy.
1625 So if you are using bzImage for capturing the crash dump,
1626 leave the value here unchanged to 0x1000000 and set
1627 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1628 for capturing the crash dump change this value to start of
1629 the reserved region. In other words, it can be set based on
1630 the "X" value as specified in the "crashkernel=YM@XM"
1631 command line boot parameter passed to the panic-ed
1632 kernel. Please take a look at Documentation/kdump/kdump.txt
1633 for more details about crash dumps.
1635 Usage of bzImage for capturing the crash dump is recommended as
1636 one does not have to build two kernels. Same kernel can be used
1637 as production kernel and capture kernel. Above option should have
1638 gone away after relocatable bzImage support is introduced. But it
1639 is present because there are users out there who continue to use
1640 vmlinux for dump capture. This option should go away down the
1643 Don't change this unless you know what you are doing.
1646 bool "Build a relocatable kernel"
1649 This builds a kernel image that retains relocation information
1650 so it can be loaded someplace besides the default 1MB.
1651 The relocations tend to make the kernel binary about 10% larger,
1652 but are discarded at runtime.
1654 One use is for the kexec on panic case where the recovery kernel
1655 must live at a different physical address than the primary
1658 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1659 it has been loaded at and the compile time physical address
1660 (CONFIG_PHYSICAL_START) is ignored.
1662 # Relocation on x86-32 needs some additional build support
1663 config X86_NEED_RELOCS
1665 depends on X86_32 && RELOCATABLE
1667 config PHYSICAL_ALIGN
1668 hex "Alignment value to which kernel should be aligned" if X86_32
1670 range 0x2000 0x1000000
1672 This value puts the alignment restrictions on physical address
1673 where kernel is loaded and run from. Kernel is compiled for an
1674 address which meets above alignment restriction.
1676 If bootloader loads the kernel at a non-aligned address and
1677 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1678 address aligned to above value and run from there.
1680 If bootloader loads the kernel at a non-aligned address and
1681 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1682 load address and decompress itself to the address it has been
1683 compiled for and run from there. The address for which kernel is
1684 compiled already meets above alignment restrictions. Hence the
1685 end result is that kernel runs from a physical address meeting
1686 above alignment restrictions.
1688 Don't change this unless you know what you are doing.
1691 bool "Support for hot-pluggable CPUs"
1692 depends on SMP && HOTPLUG
1694 Say Y here to allow turning CPUs off and on. CPUs can be
1695 controlled through /sys/devices/system/cpu.
1696 ( Note: power management support will enable this option
1697 automatically on SMP systems. )
1698 Say N if you want to disable CPU hotplug.
1700 config BOOTPARAM_HOTPLUG_CPU0
1701 bool "Set default setting of cpu0_hotpluggable"
1703 depends on HOTPLUG_CPU && EXPERIMENTAL
1705 Set whether default state of cpu0_hotpluggable is on or off.
1707 Say Y here to enable CPU0 hotplug by default. If this switch
1708 is turned on, there is no need to give cpu0_hotplug kernel
1709 parameter and the CPU0 hotplug feature is enabled by default.
1711 Please note: there are two known CPU0 dependencies if you want
1712 to enable the CPU0 hotplug feature either by this switch or by
1713 cpu0_hotplug kernel parameter.
1715 First, resume from hibernate or suspend always starts from CPU0.
1716 So hibernate and suspend are prevented if CPU0 is offline.
1718 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1719 offline if any interrupt can not migrate out of CPU0. There may
1720 be other CPU0 dependencies.
1722 Please make sure the dependencies are under your control before
1723 you enable this feature.
1725 Say N if you don't want to enable CPU0 hotplug feature by default.
1726 You still can enable the CPU0 hotplug feature at boot by kernel
1727 parameter cpu0_hotplug.
1729 config DEBUG_HOTPLUG_CPU0
1731 prompt "Debug CPU0 hotplug"
1732 depends on HOTPLUG_CPU && EXPERIMENTAL
1734 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1735 soon as possible and boots up userspace with CPU0 offlined. User
1736 can online CPU0 back after boot time.
1738 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1739 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1740 compilation or giving cpu0_hotplug kernel parameter at boot.
1746 prompt "Compat VDSO support"
1747 depends on X86_32 || IA32_EMULATION
1749 Map the 32-bit VDSO to the predictable old-style address too.
1751 Say N here if you are running a sufficiently recent glibc
1752 version (2.3.3 or later), to remove the high-mapped
1753 VDSO mapping and to exclusively use the randomized VDSO.
1758 bool "Built-in kernel command line"
1760 Allow for specifying boot arguments to the kernel at
1761 build time. On some systems (e.g. embedded ones), it is
1762 necessary or convenient to provide some or all of the
1763 kernel boot arguments with the kernel itself (that is,
1764 to not rely on the boot loader to provide them.)
1766 To compile command line arguments into the kernel,
1767 set this option to 'Y', then fill in the
1768 the boot arguments in CONFIG_CMDLINE.
1770 Systems with fully functional boot loaders (i.e. non-embedded)
1771 should leave this option set to 'N'.
1774 string "Built-in kernel command string"
1775 depends on CMDLINE_BOOL
1778 Enter arguments here that should be compiled into the kernel
1779 image and used at boot time. If the boot loader provides a
1780 command line at boot time, it is appended to this string to
1781 form the full kernel command line, when the system boots.
1783 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1784 change this behavior.
1786 In most cases, the command line (whether built-in or provided
1787 by the boot loader) should specify the device for the root
1790 config CMDLINE_OVERRIDE
1791 bool "Built-in command line overrides boot loader arguments"
1792 depends on CMDLINE_BOOL
1794 Set this option to 'Y' to have the kernel ignore the boot loader
1795 command line, and use ONLY the built-in command line.
1797 This is used to work around broken boot loaders. This should
1798 be set to 'N' under normal conditions.
1802 config ARCH_ENABLE_MEMORY_HOTPLUG
1804 depends on X86_64 || (X86_32 && HIGHMEM)
1806 config ARCH_ENABLE_MEMORY_HOTREMOVE
1808 depends on MEMORY_HOTPLUG
1810 config USE_PERCPU_NUMA_NODE_ID
1814 menu "Power management and ACPI options"
1816 config ARCH_HIBERNATION_HEADER
1818 depends on X86_64 && HIBERNATION
1820 source "kernel/power/Kconfig"
1822 source "drivers/acpi/Kconfig"
1824 source "drivers/sfi/Kconfig"
1831 tristate "APM (Advanced Power Management) BIOS support"
1832 depends on X86_32 && PM_SLEEP
1834 APM is a BIOS specification for saving power using several different
1835 techniques. This is mostly useful for battery powered laptops with
1836 APM compliant BIOSes. If you say Y here, the system time will be
1837 reset after a RESUME operation, the /proc/apm device will provide
1838 battery status information, and user-space programs will receive
1839 notification of APM "events" (e.g. battery status change).
1841 If you select "Y" here, you can disable actual use of the APM
1842 BIOS by passing the "apm=off" option to the kernel at boot time.
1844 Note that the APM support is almost completely disabled for
1845 machines with more than one CPU.
1847 In order to use APM, you will need supporting software. For location
1848 and more information, read <file:Documentation/power/apm-acpi.txt>
1849 and the Battery Powered Linux mini-HOWTO, available from
1850 <http://www.tldp.org/docs.html#howto>.
1852 This driver does not spin down disk drives (see the hdparm(8)
1853 manpage ("man 8 hdparm") for that), and it doesn't turn off
1854 VESA-compliant "green" monitors.
1856 This driver does not support the TI 4000M TravelMate and the ACER
1857 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1858 desktop machines also don't have compliant BIOSes, and this driver
1859 may cause those machines to panic during the boot phase.
1861 Generally, if you don't have a battery in your machine, there isn't
1862 much point in using this driver and you should say N. If you get
1863 random kernel OOPSes or reboots that don't seem to be related to
1864 anything, try disabling/enabling this option (or disabling/enabling
1867 Some other things you should try when experiencing seemingly random,
1870 1) make sure that you have enough swap space and that it is
1872 2) pass the "no-hlt" option to the kernel
1873 3) switch on floating point emulation in the kernel and pass
1874 the "no387" option to the kernel
1875 4) pass the "floppy=nodma" option to the kernel
1876 5) pass the "mem=4M" option to the kernel (thereby disabling
1877 all but the first 4 MB of RAM)
1878 6) make sure that the CPU is not over clocked.
1879 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1880 8) disable the cache from your BIOS settings
1881 9) install a fan for the video card or exchange video RAM
1882 10) install a better fan for the CPU
1883 11) exchange RAM chips
1884 12) exchange the motherboard.
1886 To compile this driver as a module, choose M here: the
1887 module will be called apm.
1891 config APM_IGNORE_USER_SUSPEND
1892 bool "Ignore USER SUSPEND"
1894 This option will ignore USER SUSPEND requests. On machines with a
1895 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1896 series notebooks, it is necessary to say Y because of a BIOS bug.
1898 config APM_DO_ENABLE
1899 bool "Enable PM at boot time"
1901 Enable APM features at boot time. From page 36 of the APM BIOS
1902 specification: "When disabled, the APM BIOS does not automatically
1903 power manage devices, enter the Standby State, enter the Suspend
1904 State, or take power saving steps in response to CPU Idle calls."
1905 This driver will make CPU Idle calls when Linux is idle (unless this
1906 feature is turned off -- see "Do CPU IDLE calls", below). This
1907 should always save battery power, but more complicated APM features
1908 will be dependent on your BIOS implementation. You may need to turn
1909 this option off if your computer hangs at boot time when using APM
1910 support, or if it beeps continuously instead of suspending. Turn
1911 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1912 T400CDT. This is off by default since most machines do fine without
1916 bool "Make CPU Idle calls when idle"
1918 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1919 On some machines, this can activate improved power savings, such as
1920 a slowed CPU clock rate, when the machine is idle. These idle calls
1921 are made after the idle loop has run for some length of time (e.g.,
1922 333 mS). On some machines, this will cause a hang at boot time or
1923 whenever the CPU becomes idle. (On machines with more than one CPU,
1924 this option does nothing.)
1926 config APM_DISPLAY_BLANK
1927 bool "Enable console blanking using APM"
1929 Enable console blanking using the APM. Some laptops can use this to
1930 turn off the LCD backlight when the screen blanker of the Linux
1931 virtual console blanks the screen. Note that this is only used by
1932 the virtual console screen blanker, and won't turn off the backlight
1933 when using the X Window system. This also doesn't have anything to
1934 do with your VESA-compliant power-saving monitor. Further, this
1935 option doesn't work for all laptops -- it might not turn off your
1936 backlight at all, or it might print a lot of errors to the console,
1937 especially if you are using gpm.
1939 config APM_ALLOW_INTS
1940 bool "Allow interrupts during APM BIOS calls"
1942 Normally we disable external interrupts while we are making calls to
1943 the APM BIOS as a measure to lessen the effects of a badly behaving
1944 BIOS implementation. The BIOS should reenable interrupts if it
1945 needs to. Unfortunately, some BIOSes do not -- especially those in
1946 many of the newer IBM Thinkpads. If you experience hangs when you
1947 suspend, try setting this to Y. Otherwise, say N.
1951 source "drivers/cpufreq/Kconfig"
1953 source "drivers/cpuidle/Kconfig"
1955 source "drivers/idle/Kconfig"
1960 menu "Bus options (PCI etc.)"
1965 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1967 Find out whether you have a PCI motherboard. PCI is the name of a
1968 bus system, i.e. the way the CPU talks to the other stuff inside
1969 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1970 VESA. If you have PCI, say Y, otherwise N.
1973 prompt "PCI access mode"
1974 depends on X86_32 && PCI
1977 On PCI systems, the BIOS can be used to detect the PCI devices and
1978 determine their configuration. However, some old PCI motherboards
1979 have BIOS bugs and may crash if this is done. Also, some embedded
1980 PCI-based systems don't have any BIOS at all. Linux can also try to
1981 detect the PCI hardware directly without using the BIOS.
1983 With this option, you can specify how Linux should detect the
1984 PCI devices. If you choose "BIOS", the BIOS will be used,
1985 if you choose "Direct", the BIOS won't be used, and if you
1986 choose "MMConfig", then PCI Express MMCONFIG will be used.
1987 If you choose "Any", the kernel will try MMCONFIG, then the
1988 direct access method and falls back to the BIOS if that doesn't
1989 work. If unsure, go with the default, which is "Any".
1994 config PCI_GOMMCONFIG
2011 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2013 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2016 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2020 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2024 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2028 depends on PCI && XEN
2036 bool "Support mmconfig PCI config space access"
2037 depends on X86_64 && PCI && ACPI
2039 config PCI_CNB20LE_QUIRK
2040 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2041 depends on PCI && EXPERIMENTAL
2043 Read the PCI windows out of the CNB20LE host bridge. This allows
2044 PCI hotplug to work on systems with the CNB20LE chipset which do
2047 There's no public spec for this chipset, and this functionality
2048 is known to be incomplete.
2050 You should say N unless you know you need this.
2052 source "drivers/pci/pcie/Kconfig"
2054 source "drivers/pci/Kconfig"
2056 # x86_64 have no ISA slots, but can have ISA-style DMA.
2058 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2061 Enables ISA-style DMA support for devices requiring such controllers.
2069 Find out whether you have ISA slots on your motherboard. ISA is the
2070 name of a bus system, i.e. the way the CPU talks to the other stuff
2071 inside your box. Other bus systems are PCI, EISA, MicroChannel
2072 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2073 newer boards don't support it. If you have ISA, say Y, otherwise N.
2079 The Extended Industry Standard Architecture (EISA) bus was
2080 developed as an open alternative to the IBM MicroChannel bus.
2082 The EISA bus provided some of the features of the IBM MicroChannel
2083 bus while maintaining backward compatibility with cards made for
2084 the older ISA bus. The EISA bus saw limited use between 1988 and
2085 1995 when it was made obsolete by the PCI bus.
2087 Say Y here if you are building a kernel for an EISA-based machine.
2091 source "drivers/eisa/Kconfig"
2094 tristate "NatSemi SCx200 support"
2096 This provides basic support for National Semiconductor's
2097 (now AMD's) Geode processors. The driver probes for the
2098 PCI-IDs of several on-chip devices, so its a good dependency
2099 for other scx200_* drivers.
2101 If compiled as a module, the driver is named scx200.
2103 config SCx200HR_TIMER
2104 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2108 This driver provides a clocksource built upon the on-chip
2109 27MHz high-resolution timer. Its also a workaround for
2110 NSC Geode SC-1100's buggy TSC, which loses time when the
2111 processor goes idle (as is done by the scheduler). The
2112 other workaround is idle=poll boot option.
2115 bool "One Laptop Per Child support"
2122 Add support for detecting the unique features of the OLPC
2126 bool "OLPC XO-1 Power Management"
2127 depends on OLPC && MFD_CS5535 && PM_SLEEP
2130 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2133 bool "OLPC XO-1 Real Time Clock"
2134 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2136 Add support for the XO-1 real time clock, which can be used as a
2137 programmable wakeup source.
2140 bool "OLPC XO-1 SCI extras"
2141 depends on OLPC && OLPC_XO1_PM
2146 Add support for SCI-based features of the OLPC XO-1 laptop:
2147 - EC-driven system wakeups
2151 - AC adapter status updates
2152 - Battery status updates
2154 config OLPC_XO15_SCI
2155 bool "OLPC XO-1.5 SCI extras"
2156 depends on OLPC && ACPI
2159 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2160 - EC-driven system wakeups
2161 - AC adapter status updates
2162 - Battery status updates
2165 bool "PCEngines ALIX System Support (LED setup)"
2168 This option enables system support for the PCEngines ALIX.
2169 At present this just sets up LEDs for GPIO control on
2170 ALIX2/3/6 boards. However, other system specific setup should
2173 Note: You must still enable the drivers for GPIO and LED support
2174 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2176 Note: You have to set alix.force=1 for boards with Award BIOS.
2179 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2182 This option enables system support for the Soekris Engineering net5501.
2185 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2189 This option enables system support for the Traverse Technologies GEOS.
2195 depends on CPU_SUP_AMD && PCI
2197 source "drivers/pcmcia/Kconfig"
2199 source "drivers/pci/hotplug/Kconfig"
2202 bool "RapidIO support"
2206 If you say Y here, the kernel will include drivers and
2207 infrastructure code to support RapidIO interconnect devices.
2209 source "drivers/rapidio/Kconfig"
2214 menu "Executable file formats / Emulations"
2216 source "fs/Kconfig.binfmt"
2218 config IA32_EMULATION
2219 bool "IA32 Emulation"
2221 select COMPAT_BINFMT_ELF
2224 Include code to run legacy 32-bit programs under a
2225 64-bit kernel. You should likely turn this on, unless you're
2226 100% sure that you don't have any 32-bit programs left.
2229 tristate "IA32 a.out support"
2230 depends on IA32_EMULATION
2232 Support old a.out binaries in the 32bit emulation.
2235 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2236 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2238 Include code to run binaries for the x32 native 32-bit ABI
2239 for 64-bit processors. An x32 process gets access to the
2240 full 64-bit register file and wide data path while leaving
2241 pointers at 32 bits for smaller memory footprint.
2243 You will need a recent binutils (2.22 or later) with
2244 elf32_x86_64 support enabled to compile a kernel with this
2249 depends on IA32_EMULATION || X86_X32
2250 select ARCH_WANT_OLD_COMPAT_IPC
2253 config COMPAT_FOR_U64_ALIGNMENT
2256 config SYSVIPC_COMPAT
2268 config HAVE_ATOMIC_IOMAP
2272 config HAVE_TEXT_POKE_SMP
2274 select STOP_MACHINE if SMP
2276 config X86_DEV_DMA_OPS
2278 depends on X86_64 || STA2X11
2280 config X86_DMA_REMAP
2284 source "net/Kconfig"
2286 source "drivers/Kconfig"
2288 source "drivers/firmware/Kconfig"
2292 source "arch/x86/Kconfig.debug"
2294 source "security/Kconfig"
2296 source "crypto/Kconfig"
2298 source "arch/x86/kvm/Kconfig"
2300 source "lib/Kconfig"
git.samba.org / sfrench / cifs-2.6.git / blob