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
27 select HAVE_PCSPKR_PLATFORM
28 select HAVE_PERF_EVENTS
30 select HAVE_IOREMAP_PROT
33 select HAVE_MEMBLOCK_NODE_MAP
34 select ARCH_DISCARD_MEMBLOCK
35 select ARCH_WANT_OPTIONAL_GPIOLIB
36 select ARCH_WANT_FRAME_POINTERS
38 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
39 select HAVE_KRETPROBES
41 select HAVE_FTRACE_MCOUNT_RECORD
42 select HAVE_FENTRY if X86_64
43 select HAVE_C_RECORDMCOUNT
44 select HAVE_DYNAMIC_FTRACE
45 select HAVE_FUNCTION_TRACER
46 select HAVE_FUNCTION_GRAPH_TRACER
47 select HAVE_FUNCTION_GRAPH_FP_TEST
48 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
49 select HAVE_SYSCALL_TRACEPOINTS
50 select SYSCTL_EXCEPTION_TRACE
53 select HAVE_ARCH_TRACEHOOK
54 select HAVE_GENERIC_DMA_COHERENT if X86_32
55 select HAVE_EFFICIENT_UNALIGNED_ACCESS
56 select USER_STACKTRACE_SUPPORT
57 select HAVE_REGS_AND_STACK_ACCESS_API
58 select HAVE_DMA_API_DEBUG
59 select HAVE_KERNEL_GZIP
60 select HAVE_KERNEL_BZIP2
61 select HAVE_KERNEL_LZMA
63 select HAVE_KERNEL_LZO
64 select HAVE_HW_BREAKPOINT
65 select HAVE_MIXED_BREAKPOINTS_REGS
67 select HAVE_PERF_EVENTS_NMI
69 select HAVE_PERF_USER_STACK_DUMP
70 select HAVE_DEBUG_KMEMLEAK
72 select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386
73 select HAVE_CMPXCHG_LOCAL if !M386
74 select HAVE_CMPXCHG_DOUBLE
75 select HAVE_ARCH_KMEMCHECK
76 select HAVE_USER_RETURN_NOTIFIER
77 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
78 select HAVE_ARCH_JUMP_LABEL
79 select HAVE_TEXT_POKE_SMP
80 select HAVE_GENERIC_HARDIRQS
81 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
83 select GENERIC_FIND_FIRST_BIT
84 select GENERIC_IRQ_PROBE
85 select GENERIC_PENDING_IRQ if SMP
86 select GENERIC_IRQ_SHOW
87 select GENERIC_CLOCKEVENTS_MIN_ADJUST
88 select IRQ_FORCED_THREADING
89 select USE_GENERIC_SMP_HELPERS if SMP
90 select HAVE_BPF_JIT if X86_64
91 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
93 select ARCH_HAVE_NMI_SAFE_CMPXCHG
95 select DCACHE_WORD_ACCESS
96 select GENERIC_SMP_IDLE_THREAD
97 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
98 select HAVE_ARCH_SECCOMP_FILTER
99 select BUILDTIME_EXTABLE_SORT
100 select GENERIC_CMOS_UPDATE
101 select CLOCKSOURCE_WATCHDOG
102 select GENERIC_CLOCKEVENTS
103 select ARCH_CLOCKSOURCE_DATA if X86_64
104 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
105 select GENERIC_TIME_VSYSCALL if X86_64
106 select KTIME_SCALAR if X86_32
107 select GENERIC_STRNCPY_FROM_USER
108 select GENERIC_STRNLEN_USER
109 select HAVE_RCU_USER_QS if X86_64
110 select HAVE_IRQ_TIME_ACCOUNTING
111 select GENERIC_KERNEL_THREAD
112 select GENERIC_KERNEL_EXECVE
113 select MODULES_USE_ELF_REL if X86_32
114 select MODULES_USE_ELF_RELA if X86_64
116 config INSTRUCTION_DECODER
118 depends on KPROBES || PERF_EVENTS || UPROBES
122 default "elf32-i386" if X86_32
123 default "elf64-x86-64" if X86_64
125 config ARCH_DEFCONFIG
127 default "arch/x86/configs/i386_defconfig" if X86_32
128 default "arch/x86/configs/x86_64_defconfig" if X86_64
130 config LOCKDEP_SUPPORT
133 config STACKTRACE_SUPPORT
136 config HAVE_LATENCYTOP_SUPPORT
145 config NEED_DMA_MAP_STATE
147 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
149 config NEED_SG_DMA_LENGTH
152 config GENERIC_ISA_DMA
154 depends on ISA_DMA_API
159 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
161 config GENERIC_BUG_RELATIVE_POINTERS
164 config GENERIC_HWEIGHT
170 config ARCH_MAY_HAVE_PC_FDC
172 depends on ISA_DMA_API
174 config RWSEM_GENERIC_SPINLOCK
178 config RWSEM_XCHGADD_ALGORITHM
182 config GENERIC_CALIBRATE_DELAY
185 config ARCH_HAS_CPU_RELAX
188 config ARCH_HAS_DEFAULT_IDLE
191 config ARCH_HAS_CACHE_LINE_SIZE
194 config ARCH_HAS_CPU_AUTOPROBE
197 config HAVE_SETUP_PER_CPU_AREA
200 config NEED_PER_CPU_EMBED_FIRST_CHUNK
203 config NEED_PER_CPU_PAGE_FIRST_CHUNK
206 config ARCH_HIBERNATION_POSSIBLE
209 config ARCH_SUSPEND_POSSIBLE
220 config ARCH_SUPPORTS_OPTIMIZED_INLINING
223 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
226 config HAVE_INTEL_TXT
228 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
232 depends on X86_32 && SMP
236 depends on X86_64 && SMP
242 config X86_32_LAZY_GS
244 depends on X86_32 && !CC_STACKPROTECTOR
246 config ARCH_HWEIGHT_CFLAGS
248 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
249 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
251 config ARCH_CPU_PROBE_RELEASE
253 depends on HOTPLUG_CPU
255 config ARCH_SUPPORTS_UPROBES
258 source "init/Kconfig"
259 source "kernel/Kconfig.freezer"
261 menu "Processor type and features"
264 bool "DMA memory allocation support" if EXPERT
267 DMA memory allocation support allows devices with less than 32-bit
268 addressing to allocate within the first 16MB of address space.
269 Disable if no such devices will be used.
274 bool "Symmetric multi-processing support"
276 This enables support for systems with more than one CPU. If you have
277 a system with only one CPU, like most personal computers, say N. If
278 you have a system with more than one CPU, say Y.
280 If you say N here, the kernel will run on single and multiprocessor
281 machines, but will use only one CPU of a multiprocessor machine. If
282 you say Y here, the kernel will run on many, but not all,
283 singleprocessor machines. On a singleprocessor machine, the kernel
284 will run faster if you say N here.
286 Note that if you say Y here and choose architecture "586" or
287 "Pentium" under "Processor family", the kernel will not work on 486
288 architectures. Similarly, multiprocessor kernels for the "PPro"
289 architecture may not work on all Pentium based boards.
291 People using multiprocessor machines who say Y here should also say
292 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
293 Management" code will be disabled if you say Y here.
295 See also <file:Documentation/x86/i386/IO-APIC.txt>,
296 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
297 <http://www.tldp.org/docs.html#howto>.
299 If you don't know what to do here, say N.
302 bool "Support x2apic"
303 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
305 This enables x2apic support on CPUs that have this feature.
307 This allows 32-bit apic IDs (so it can support very large systems),
308 and accesses the local apic via MSRs not via mmio.
310 If you don't know what to do here, say N.
313 bool "Enable MPS table" if ACPI
315 depends on X86_LOCAL_APIC
317 For old smp systems that do not have proper acpi support. Newer systems
318 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
321 bool "Support for big SMP systems with more than 8 CPUs"
322 depends on X86_32 && SMP
324 This option is needed for the systems that have more than 8 CPUs
327 config X86_EXTENDED_PLATFORM
328 bool "Support for extended (non-PC) x86 platforms"
331 If you disable this option then the kernel will only support
332 standard PC platforms. (which covers the vast majority of
335 If you enable this option then you'll be able to select support
336 for the following (non-PC) 32 bit x86 platforms:
340 SGI 320/540 (Visual Workstation)
341 STA2X11-based (e.g. Northville)
342 Summit/EXA (IBM x440)
343 Unisys ES7000 IA32 series
344 Moorestown MID devices
346 If you have one of these systems, or if you want to build a
347 generic distribution kernel, say Y here - otherwise say N.
351 config X86_EXTENDED_PLATFORM
352 bool "Support for extended (non-PC) x86 platforms"
355 If you disable this option then the kernel will only support
356 standard PC platforms. (which covers the vast majority of
359 If you enable this option then you'll be able to select support
360 for the following (non-PC) 64 bit x86 platforms:
365 If you have one of these systems, or if you want to build a
366 generic distribution kernel, say Y here - otherwise say N.
368 # This is an alphabetically sorted list of 64 bit extended platforms
369 # Please maintain the alphabetic order if and when there are additions
371 bool "Numascale NumaChip"
373 depends on X86_EXTENDED_PLATFORM
376 depends on X86_X2APIC
378 Adds support for Numascale NumaChip large-SMP systems. Needed to
379 enable more than ~168 cores.
380 If you don't have one of these, you should say N here.
384 select PARAVIRT_GUEST
386 depends on X86_64 && PCI
387 depends on X86_EXTENDED_PLATFORM
390 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
391 supposed to run on these EM64T-based machines. Only choose this option
392 if you have one of these machines.
395 bool "SGI Ultraviolet"
397 depends on X86_EXTENDED_PLATFORM
399 depends on X86_X2APIC
401 This option is needed in order to support SGI Ultraviolet systems.
402 If you don't have one of these, you should say N here.
404 # Following is an alphabetically sorted list of 32 bit extended platforms
405 # Please maintain the alphabetic order if and when there are additions
408 bool "CE4100 TV platform"
410 depends on PCI_GODIRECT
412 depends on X86_EXTENDED_PLATFORM
413 select X86_REBOOTFIXUPS
415 select OF_EARLY_FLATTREE
418 Select for the Intel CE media processor (CE4100) SOC.
419 This option compiles in support for the CE4100 SOC for settop
420 boxes and media devices.
422 config X86_WANT_INTEL_MID
423 bool "Intel MID platform support"
425 depends on X86_EXTENDED_PLATFORM
427 Select to build a kernel capable of supporting Intel MID platform
428 systems which do not have the PCI legacy interfaces (Moorestown,
429 Medfield). If you are building for a PC class system say N here.
431 if X86_WANT_INTEL_MID
437 bool "Medfield MID platform"
440 depends on X86_IO_APIC
448 select X86_PLATFORM_DEVICES
449 select MFD_INTEL_MSIC
451 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
452 Internet Device(MID) platform.
453 Unlike standard x86 PCs, Medfield does not have many legacy devices
454 nor standard legacy replacement devices/features. e.g. Medfield does
455 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
460 bool "RDC R-321x SoC"
462 depends on X86_EXTENDED_PLATFORM
464 select X86_REBOOTFIXUPS
466 This option is needed for RDC R-321x system-on-chip, also known
468 If you don't have one of these chips, you should say N here.
470 config X86_32_NON_STANDARD
471 bool "Support non-standard 32-bit SMP architectures"
472 depends on X86_32 && SMP
473 depends on X86_EXTENDED_PLATFORM
475 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
476 STA2X11, default subarchitectures. It is intended for a generic
477 binary kernel. If you select them all, kernel will probe it
478 one by one and will fallback to default.
480 # Alphabetically sorted list of Non standard 32 bit platforms
483 bool "NUMAQ (IBM/Sequent)"
484 depends on X86_32_NON_STANDARD
489 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
490 NUMA multiquad box. This changes the way that processors are
491 bootstrapped, and uses Clustered Logical APIC addressing mode instead
492 of Flat Logical. You will need a new lynxer.elf file to flash your
493 firmware with - send email to <Martin.Bligh@us.ibm.com>.
495 config X86_SUPPORTS_MEMORY_FAILURE
497 # MCE code calls memory_failure():
499 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
500 depends on !X86_NUMAQ
501 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
502 depends on X86_64 || !SPARSEMEM
503 select ARCH_SUPPORTS_MEMORY_FAILURE
506 bool "SGI 320/540 (Visual Workstation)"
507 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
508 depends on X86_32_NON_STANDARD
510 The SGI Visual Workstation series is an IA32-based workstation
511 based on SGI systems chips with some legacy PC hardware attached.
513 Say Y here to create a kernel to run on the SGI 320 or 540.
515 A kernel compiled for the Visual Workstation will run on general
516 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
519 bool "STA2X11 Companion Chip Support"
520 depends on X86_32_NON_STANDARD && PCI
521 select X86_DEV_DMA_OPS
525 select ARCH_REQUIRE_GPIOLIB
528 This adds support for boards based on the STA2X11 IO-Hub,
529 a.k.a. "ConneXt". The chip is used in place of the standard
530 PC chipset, so all "standard" peripherals are missing. If this
531 option is selected the kernel will still be able to boot on
532 standard PC machines.
535 bool "Summit/EXA (IBM x440)"
536 depends on X86_32_NON_STANDARD
538 This option is needed for IBM systems that use the Summit/EXA chipset.
539 In particular, it is needed for the x440.
542 bool "Unisys ES7000 IA32 series"
543 depends on X86_32_NON_STANDARD && X86_BIGSMP
545 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
546 supposed to run on an IA32-based Unisys ES7000 system.
549 tristate "Eurobraille/Iris poweroff module"
552 The Iris machines from EuroBraille do not have APM or ACPI support
553 to shut themselves down properly. A special I/O sequence is
554 needed to do so, which is what this module does at
557 This is only for Iris machines from EuroBraille.
561 config SCHED_OMIT_FRAME_POINTER
563 prompt "Single-depth WCHAN output"
566 Calculate simpler /proc/<PID>/wchan values. If this option
567 is disabled then wchan values will recurse back to the
568 caller function. This provides more accurate wchan values,
569 at the expense of slightly more scheduling overhead.
571 If in doubt, say "Y".
573 config KVMTOOL_TEST_ENABLE
574 bool "Enable options to create a bootable tools/kvm/ kernel"
580 select NETWORK_FILESYSTEMS
584 select SERIAL_8250_CONSOLE
589 select HAVE_ARCH_KGDB
592 select KGDB_SERIAL_CONSOLE
593 select VIRTUALIZATION
598 select VIRTIO_CONSOLE
604 menuconfig PARAVIRT_GUEST
605 bool "Paravirtualized guest support"
607 Say Y here to get to see options related to running Linux under
608 various hypervisors. This option alone does not add any kernel code.
610 If you say N, all options in this submenu will be skipped and disabled.
614 config PARAVIRT_TIME_ACCOUNTING
615 bool "Paravirtual steal time accounting"
619 Select this option to enable fine granularity task steal time
620 accounting. Time spent executing other tasks in parallel with
621 the current vCPU is discounted from the vCPU power. To account for
622 that, there can be a small performance impact.
624 If in doubt, say N here.
626 source "arch/x86/xen/Kconfig"
629 bool "KVM Guest support (including kvmclock)"
632 select PARAVIRT_CLOCK
633 default y if PARAVIRT_GUEST
635 This option enables various optimizations for running under the KVM
636 hypervisor. It includes a paravirtualized clock, so that instead
637 of relying on a PIT (or probably other) emulation by the
638 underlying device model, the host provides the guest with
639 timing infrastructure such as time of day, and system time
641 source "arch/x86/lguest/Kconfig"
644 bool "Enable paravirtualization code"
646 This changes the kernel so it can modify itself when it is run
647 under a hypervisor, potentially improving performance significantly
648 over full virtualization. However, when run without a hypervisor
649 the kernel is theoretically slower and slightly larger.
651 config PARAVIRT_SPINLOCKS
652 bool "Paravirtualization layer for spinlocks"
653 depends on PARAVIRT && SMP && EXPERIMENTAL
655 Paravirtualized spinlocks allow a pvops backend to replace the
656 spinlock implementation with something virtualization-friendly
657 (for example, block the virtual CPU rather than spinning).
659 Unfortunately the downside is an up to 5% performance hit on
660 native kernels, with various workloads.
662 If you are unsure how to answer this question, answer N.
664 config PARAVIRT_CLOCK
669 config PARAVIRT_DEBUG
670 bool "paravirt-ops debugging"
671 depends on PARAVIRT && DEBUG_KERNEL
673 Enable to debug paravirt_ops internals. Specifically, BUG if
674 a paravirt_op is missing when it is called.
682 This option adds a kernel parameter 'memtest', which allows memtest
684 memtest=0, mean disabled; -- default
685 memtest=1, mean do 1 test pattern;
687 memtest=4, mean do 4 test patterns.
688 If you are unsure how to answer this question, answer N.
690 config X86_SUMMIT_NUMA
692 depends on X86_32 && NUMA && X86_32_NON_STANDARD
694 config X86_CYCLONE_TIMER
696 depends on X86_SUMMIT
698 source "arch/x86/Kconfig.cpu"
702 prompt "HPET Timer Support" if X86_32
704 Use the IA-PC HPET (High Precision Event Timer) to manage
705 time in preference to the PIT and RTC, if a HPET is
707 HPET is the next generation timer replacing legacy 8254s.
708 The HPET provides a stable time base on SMP
709 systems, unlike the TSC, but it is more expensive to access,
710 as it is off-chip. You can find the HPET spec at
711 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
713 You can safely choose Y here. However, HPET will only be
714 activated if the platform and the BIOS support this feature.
715 Otherwise the 8254 will be used for timing services.
717 Choose N to continue using the legacy 8254 timer.
719 config HPET_EMULATE_RTC
721 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
724 def_bool y if X86_INTEL_MID
725 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
727 depends on X86_INTEL_MID && SFI
729 APB timer is the replacement for 8254, HPET on X86 MID platforms.
730 The APBT provides a stable time base on SMP
731 systems, unlike the TSC, but it is more expensive to access,
732 as it is off-chip. APB timers are always running regardless of CPU
733 C states, they are used as per CPU clockevent device when possible.
735 # Mark as expert because too many people got it wrong.
736 # The code disables itself when not needed.
739 bool "Enable DMI scanning" if EXPERT
741 Enabled scanning of DMI to identify machine quirks. Say Y
742 here unless you have verified that your setup is not
743 affected by entries in the DMI blacklist. Required by PNP
747 bool "GART IOMMU support" if EXPERT
750 depends on X86_64 && PCI && AMD_NB
752 Support for full DMA access of devices with 32bit memory access only
753 on systems with more than 3GB. This is usually needed for USB,
754 sound, many IDE/SATA chipsets and some other devices.
755 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
756 based hardware IOMMU and a software bounce buffer based IOMMU used
757 on Intel systems and as fallback.
758 The code is only active when needed (enough memory and limited
759 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
763 bool "IBM Calgary IOMMU support"
765 depends on X86_64 && PCI && EXPERIMENTAL
767 Support for hardware IOMMUs in IBM's xSeries x366 and x460
768 systems. Needed to run systems with more than 3GB of memory
769 properly with 32-bit PCI devices that do not support DAC
770 (Double Address Cycle). Calgary also supports bus level
771 isolation, where all DMAs pass through the IOMMU. This
772 prevents them from going anywhere except their intended
773 destination. This catches hard-to-find kernel bugs and
774 mis-behaving drivers and devices that do not use the DMA-API
775 properly to set up their DMA buffers. The IOMMU can be
776 turned off at boot time with the iommu=off parameter.
777 Normally the kernel will make the right choice by itself.
780 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
782 prompt "Should Calgary be enabled by default?"
783 depends on CALGARY_IOMMU
785 Should Calgary be enabled by default? if you choose 'y', Calgary
786 will be used (if it exists). If you choose 'n', Calgary will not be
787 used even if it exists. If you choose 'n' and would like to use
788 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
791 # need this always selected by IOMMU for the VIA workaround
795 Support for software bounce buffers used on x86-64 systems
796 which don't have a hardware IOMMU. Using this PCI devices
797 which can only access 32-bits of memory can be used on systems
798 with more than 3 GB of memory.
803 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
806 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
807 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
808 select CPUMASK_OFFSTACK
810 Enable maximum number of CPUS and NUMA Nodes for this architecture.
814 int "Maximum number of CPUs" if SMP && !MAXSMP
815 range 2 8 if SMP && X86_32 && !X86_BIGSMP
816 range 2 512 if SMP && !MAXSMP
818 default "4096" if MAXSMP
819 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
822 This allows you to specify the maximum number of CPUs which this
823 kernel will support. The maximum supported value is 512 and the
824 minimum value which makes sense is 2.
826 This is purely to save memory - each supported CPU adds
827 approximately eight kilobytes to the kernel image.
830 bool "SMT (Hyperthreading) scheduler support"
833 SMT scheduler support improves the CPU scheduler's decision making
834 when dealing with Intel Pentium 4 chips with HyperThreading at a
835 cost of slightly increased overhead in some places. If unsure say
840 prompt "Multi-core scheduler support"
843 Multi-core scheduler support improves the CPU scheduler's decision
844 making when dealing with multi-core CPU chips at a cost of slightly
845 increased overhead in some places. If unsure say N here.
847 source "kernel/Kconfig.preempt"
850 bool "Local APIC support on uniprocessors"
851 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
853 A local APIC (Advanced Programmable Interrupt Controller) is an
854 integrated interrupt controller in the CPU. If you have a single-CPU
855 system which has a processor with a local APIC, you can say Y here to
856 enable and use it. If you say Y here even though your machine doesn't
857 have a local APIC, then the kernel will still run with no slowdown at
858 all. The local APIC supports CPU-generated self-interrupts (timer,
859 performance counters), and the NMI watchdog which detects hard
863 bool "IO-APIC support on uniprocessors"
864 depends on X86_UP_APIC
866 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
867 SMP-capable replacement for PC-style interrupt controllers. Most
868 SMP systems and many recent uniprocessor systems have one.
870 If you have a single-CPU system with an IO-APIC, you can say Y here
871 to use it. If you say Y here even though your machine doesn't have
872 an IO-APIC, then the kernel will still run with no slowdown at all.
874 config X86_LOCAL_APIC
876 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
880 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
882 config X86_VISWS_APIC
884 depends on X86_32 && X86_VISWS
886 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
887 bool "Reroute for broken boot IRQs"
888 depends on X86_IO_APIC
890 This option enables a workaround that fixes a source of
891 spurious interrupts. This is recommended when threaded
892 interrupt handling is used on systems where the generation of
893 superfluous "boot interrupts" cannot be disabled.
895 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
896 entry in the chipset's IO-APIC is masked (as, e.g. the RT
897 kernel does during interrupt handling). On chipsets where this
898 boot IRQ generation cannot be disabled, this workaround keeps
899 the original IRQ line masked so that only the equivalent "boot
900 IRQ" is delivered to the CPUs. The workaround also tells the
901 kernel to set up the IRQ handler on the boot IRQ line. In this
902 way only one interrupt is delivered to the kernel. Otherwise
903 the spurious second interrupt may cause the kernel to bring
904 down (vital) interrupt lines.
906 Only affects "broken" chipsets. Interrupt sharing may be
907 increased on these systems.
910 bool "Machine Check / overheating reporting"
913 Machine Check support allows the processor to notify the
914 kernel if it detects a problem (e.g. overheating, data corruption).
915 The action the kernel takes depends on the severity of the problem,
916 ranging from warning messages to halting the machine.
920 prompt "Intel MCE features"
921 depends on X86_MCE && X86_LOCAL_APIC
923 Additional support for intel specific MCE features such as
928 prompt "AMD MCE features"
929 depends on X86_MCE && X86_LOCAL_APIC
931 Additional support for AMD specific MCE features such as
932 the DRAM Error Threshold.
934 config X86_ANCIENT_MCE
935 bool "Support for old Pentium 5 / WinChip machine checks"
936 depends on X86_32 && X86_MCE
938 Include support for machine check handling on old Pentium 5 or WinChip
939 systems. These typically need to be enabled explicitely on the command
942 config X86_MCE_THRESHOLD
943 depends on X86_MCE_AMD || X86_MCE_INTEL
946 config X86_MCE_INJECT
948 tristate "Machine check injector support"
950 Provide support for injecting machine checks for testing purposes.
951 If you don't know what a machine check is and you don't do kernel
952 QA it is safe to say n.
954 config X86_THERMAL_VECTOR
956 depends on X86_MCE_INTEL
959 bool "Enable VM86 support" if EXPERT
963 This option is required by programs like DOSEMU to run 16-bit legacy
964 code on X86 processors. It also may be needed by software like
965 XFree86 to initialize some video cards via BIOS. Disabling this
966 option saves about 6k.
969 tristate "Toshiba Laptop support"
972 This adds a driver to safely access the System Management Mode of
973 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
974 not work on models with a Phoenix BIOS. The System Management Mode
975 is used to set the BIOS and power saving options on Toshiba portables.
977 For information on utilities to make use of this driver see the
978 Toshiba Linux utilities web site at:
979 <http://www.buzzard.org.uk/toshiba/>.
981 Say Y if you intend to run this kernel on a Toshiba portable.
985 tristate "Dell laptop support"
988 This adds a driver to safely access the System Management Mode
989 of the CPU on the Dell Inspiron 8000. The System Management Mode
990 is used to read cpu temperature and cooling fan status and to
991 control the fans on the I8K portables.
993 This driver has been tested only on the Inspiron 8000 but it may
994 also work with other Dell laptops. You can force loading on other
995 models by passing the parameter `force=1' to the module. Use at
998 For information on utilities to make use of this driver see the
999 I8K Linux utilities web site at:
1000 <http://people.debian.org/~dz/i8k/>
1002 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1005 config X86_REBOOTFIXUPS
1006 bool "Enable X86 board specific fixups for reboot"
1009 This enables chipset and/or board specific fixups to be done
1010 in order to get reboot to work correctly. This is only needed on
1011 some combinations of hardware and BIOS. The symptom, for which
1012 this config is intended, is when reboot ends with a stalled/hung
1015 Currently, the only fixup is for the Geode machines using
1016 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1018 Say Y if you want to enable the fixup. Currently, it's safe to
1019 enable this option even if you don't need it.
1023 tristate "CPU microcode loading support"
1027 If you say Y here, you will be able to update the microcode on
1028 certain Intel and AMD processors. The Intel support is for the
1029 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1030 Xeon etc. The AMD support is for families 0x10 and later. You will
1031 obviously need the actual microcode binary data itself which is not
1032 shipped with the Linux kernel.
1034 This option selects the general module only, you need to select
1035 at least one vendor specific module as well.
1037 To compile this driver as a module, choose M here: the module
1038 will be called microcode.
1040 config MICROCODE_INTEL
1041 bool "Intel microcode loading support"
1042 depends on MICROCODE
1046 This options enables microcode patch loading support for Intel
1049 For latest news and information on obtaining all the required
1050 Intel ingredients for this driver, check:
1051 <http://www.urbanmyth.org/microcode/>.
1053 config MICROCODE_AMD
1054 bool "AMD microcode loading support"
1055 depends on MICROCODE
1058 If you select this option, microcode patch loading support for AMD
1059 processors will be enabled.
1061 config MICROCODE_OLD_INTERFACE
1063 depends on MICROCODE
1066 tristate "/dev/cpu/*/msr - Model-specific register support"
1068 This device gives privileged processes access to the x86
1069 Model-Specific Registers (MSRs). It is a character device with
1070 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1071 MSR accesses are directed to a specific CPU on multi-processor
1075 tristate "/dev/cpu/*/cpuid - CPU information support"
1077 This device gives processes access to the x86 CPUID instruction to
1078 be executed on a specific processor. It is a character device
1079 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1083 prompt "High Memory Support"
1084 default HIGHMEM64G if X86_NUMAQ
1090 depends on !X86_NUMAQ
1092 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1093 However, the address space of 32-bit x86 processors is only 4
1094 Gigabytes large. That means that, if you have a large amount of
1095 physical memory, not all of it can be "permanently mapped" by the
1096 kernel. The physical memory that's not permanently mapped is called
1099 If you are compiling a kernel which will never run on a machine with
1100 more than 1 Gigabyte total physical RAM, answer "off" here (default
1101 choice and suitable for most users). This will result in a "3GB/1GB"
1102 split: 3GB are mapped so that each process sees a 3GB virtual memory
1103 space and the remaining part of the 4GB virtual memory space is used
1104 by the kernel to permanently map as much physical memory as
1107 If the machine has between 1 and 4 Gigabytes physical RAM, then
1110 If more than 4 Gigabytes is used then answer "64GB" here. This
1111 selection turns Intel PAE (Physical Address Extension) mode on.
1112 PAE implements 3-level paging on IA32 processors. PAE is fully
1113 supported by Linux, PAE mode is implemented on all recent Intel
1114 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1115 then the kernel will not boot on CPUs that don't support PAE!
1117 The actual amount of total physical memory will either be
1118 auto detected or can be forced by using a kernel command line option
1119 such as "mem=256M". (Try "man bootparam" or see the documentation of
1120 your boot loader (lilo or loadlin) about how to pass options to the
1121 kernel at boot time.)
1123 If unsure, say "off".
1127 depends on !X86_NUMAQ
1129 Select this if you have a 32-bit processor and between 1 and 4
1130 gigabytes of physical RAM.
1134 depends on !M386 && !M486
1137 Select this if you have a 32-bit processor and more than 4
1138 gigabytes of physical RAM.
1143 depends on EXPERIMENTAL
1144 prompt "Memory split" if EXPERT
1148 Select the desired split between kernel and user memory.
1150 If the address range available to the kernel is less than the
1151 physical memory installed, the remaining memory will be available
1152 as "high memory". Accessing high memory is a little more costly
1153 than low memory, as it needs to be mapped into the kernel first.
1154 Note that increasing the kernel address space limits the range
1155 available to user programs, making the address space there
1156 tighter. Selecting anything other than the default 3G/1G split
1157 will also likely make your kernel incompatible with binary-only
1160 If you are not absolutely sure what you are doing, leave this
1164 bool "3G/1G user/kernel split"
1165 config VMSPLIT_3G_OPT
1167 bool "3G/1G user/kernel split (for full 1G low memory)"
1169 bool "2G/2G user/kernel split"
1170 config VMSPLIT_2G_OPT
1172 bool "2G/2G user/kernel split (for full 2G low memory)"
1174 bool "1G/3G user/kernel split"
1179 default 0xB0000000 if VMSPLIT_3G_OPT
1180 default 0x80000000 if VMSPLIT_2G
1181 default 0x78000000 if VMSPLIT_2G_OPT
1182 default 0x40000000 if VMSPLIT_1G
1188 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1191 bool "PAE (Physical Address Extension) Support"
1192 depends on X86_32 && !HIGHMEM4G
1194 PAE is required for NX support, and furthermore enables
1195 larger swapspace support for non-overcommit purposes. It
1196 has the cost of more pagetable lookup overhead, and also
1197 consumes more pagetable space per process.
1199 config ARCH_PHYS_ADDR_T_64BIT
1201 depends on X86_64 || X86_PAE
1203 config ARCH_DMA_ADDR_T_64BIT
1205 depends on X86_64 || HIGHMEM64G
1207 config DIRECT_GBPAGES
1208 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1212 Allow the kernel linear mapping to use 1GB pages on CPUs that
1213 support it. This can improve the kernel's performance a tiny bit by
1214 reducing TLB pressure. If in doubt, say "Y".
1216 # Common NUMA Features
1218 bool "Numa Memory Allocation and Scheduler Support"
1220 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1221 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1223 Enable NUMA (Non Uniform Memory Access) support.
1225 The kernel will try to allocate memory used by a CPU on the
1226 local memory controller of the CPU and add some more
1227 NUMA awareness to the kernel.
1229 For 64-bit this is recommended if the system is Intel Core i7
1230 (or later), AMD Opteron, or EM64T NUMA.
1232 For 32-bit this is only needed on (rare) 32-bit-only platforms
1233 that support NUMA topologies, such as NUMAQ / Summit, or if you
1234 boot a 32-bit kernel on a 64-bit NUMA platform.
1236 Otherwise, you should say N.
1238 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1239 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1243 prompt "Old style AMD Opteron NUMA detection"
1244 depends on X86_64 && NUMA && PCI
1246 Enable AMD NUMA node topology detection. You should say Y here if
1247 you have a multi processor AMD system. This uses an old method to
1248 read the NUMA configuration directly from the builtin Northbridge
1249 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1250 which also takes priority if both are compiled in.
1252 config X86_64_ACPI_NUMA
1254 prompt "ACPI NUMA detection"
1255 depends on X86_64 && NUMA && ACPI && PCI
1258 Enable ACPI SRAT based node topology detection.
1260 # Some NUMA nodes have memory ranges that span
1261 # other nodes. Even though a pfn is valid and
1262 # between a node's start and end pfns, it may not
1263 # reside on that node. See memmap_init_zone()
1265 config NODES_SPAN_OTHER_NODES
1267 depends on X86_64_ACPI_NUMA
1270 bool "NUMA emulation"
1273 Enable NUMA emulation. A flat machine will be split
1274 into virtual nodes when booted with "numa=fake=N", where N is the
1275 number of nodes. This is only useful for debugging.
1278 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1280 default "10" if MAXSMP
1281 default "6" if X86_64
1282 default "4" if X86_NUMAQ
1284 depends on NEED_MULTIPLE_NODES
1286 Specify the maximum number of NUMA Nodes available on the target
1287 system. Increases memory reserved to accommodate various tables.
1289 config HAVE_ARCH_ALLOC_REMAP
1291 depends on X86_32 && NUMA
1293 config ARCH_HAVE_MEMORY_PRESENT
1295 depends on X86_32 && DISCONTIGMEM
1297 config NEED_NODE_MEMMAP_SIZE
1299 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1301 config ARCH_FLATMEM_ENABLE
1303 depends on X86_32 && !NUMA
1305 config ARCH_DISCONTIGMEM_ENABLE
1307 depends on NUMA && X86_32
1309 config ARCH_DISCONTIGMEM_DEFAULT
1311 depends on NUMA && X86_32
1313 config ARCH_SPARSEMEM_ENABLE
1315 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1316 select SPARSEMEM_STATIC if X86_32
1317 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1319 config ARCH_SPARSEMEM_DEFAULT
1323 config ARCH_SELECT_MEMORY_MODEL
1325 depends on ARCH_SPARSEMEM_ENABLE
1327 config ARCH_MEMORY_PROBE
1329 depends on X86_64 && MEMORY_HOTPLUG
1331 config ARCH_PROC_KCORE_TEXT
1333 depends on X86_64 && PROC_KCORE
1335 config ILLEGAL_POINTER_VALUE
1338 default 0xdead000000000000 if X86_64
1343 bool "Allocate 3rd-level pagetables from highmem"
1346 The VM uses one page table entry for each page of physical memory.
1347 For systems with a lot of RAM, this can be wasteful of precious
1348 low memory. Setting this option will put user-space page table
1349 entries in high memory.
1351 config X86_CHECK_BIOS_CORRUPTION
1352 bool "Check for low memory corruption"
1354 Periodically check for memory corruption in low memory, which
1355 is suspected to be caused by BIOS. Even when enabled in the
1356 configuration, it is disabled at runtime. Enable it by
1357 setting "memory_corruption_check=1" on the kernel command
1358 line. By default it scans the low 64k of memory every 60
1359 seconds; see the memory_corruption_check_size and
1360 memory_corruption_check_period parameters in
1361 Documentation/kernel-parameters.txt to adjust this.
1363 When enabled with the default parameters, this option has
1364 almost no overhead, as it reserves a relatively small amount
1365 of memory and scans it infrequently. It both detects corruption
1366 and prevents it from affecting the running system.
1368 It is, however, intended as a diagnostic tool; if repeatable
1369 BIOS-originated corruption always affects the same memory,
1370 you can use memmap= to prevent the kernel from using that
1373 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1374 bool "Set the default setting of memory_corruption_check"
1375 depends on X86_CHECK_BIOS_CORRUPTION
1378 Set whether the default state of memory_corruption_check is
1381 config X86_RESERVE_LOW
1382 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1386 Specify the amount of low memory to reserve for the BIOS.
1388 The first page contains BIOS data structures that the kernel
1389 must not use, so that page must always be reserved.
1391 By default we reserve the first 64K of physical RAM, as a
1392 number of BIOSes are known to corrupt that memory range
1393 during events such as suspend/resume or monitor cable
1394 insertion, so it must not be used by the kernel.
1396 You can set this to 4 if you are absolutely sure that you
1397 trust the BIOS to get all its memory reservations and usages
1398 right. If you know your BIOS have problems beyond the
1399 default 64K area, you can set this to 640 to avoid using the
1400 entire low memory range.
1402 If you have doubts about the BIOS (e.g. suspend/resume does
1403 not work or there's kernel crashes after certain hardware
1404 hotplug events) then you might want to enable
1405 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1406 typical corruption patterns.
1408 Leave this to the default value of 64 if you are unsure.
1410 config MATH_EMULATION
1412 prompt "Math emulation" if X86_32
1414 Linux can emulate a math coprocessor (used for floating point
1415 operations) if you don't have one. 486DX and Pentium processors have
1416 a math coprocessor built in, 486SX and 386 do not, unless you added
1417 a 487DX or 387, respectively. (The messages during boot time can
1418 give you some hints here ["man dmesg"].) Everyone needs either a
1419 coprocessor or this emulation.
1421 If you don't have a math coprocessor, you need to say Y here; if you
1422 say Y here even though you have a coprocessor, the coprocessor will
1423 be used nevertheless. (This behavior can be changed with the kernel
1424 command line option "no387", which comes handy if your coprocessor
1425 is broken. Try "man bootparam" or see the documentation of your boot
1426 loader (lilo or loadlin) about how to pass options to the kernel at
1427 boot time.) This means that it is a good idea to say Y here if you
1428 intend to use this kernel on different machines.
1430 More information about the internals of the Linux math coprocessor
1431 emulation can be found in <file:arch/x86/math-emu/README>.
1433 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1434 kernel, it won't hurt.
1438 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1440 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1441 the Memory Type Range Registers (MTRRs) may be used to control
1442 processor access to memory ranges. This is most useful if you have
1443 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1444 allows bus write transfers to be combined into a larger transfer
1445 before bursting over the PCI/AGP bus. This can increase performance
1446 of image write operations 2.5 times or more. Saying Y here creates a
1447 /proc/mtrr file which may be used to manipulate your processor's
1448 MTRRs. Typically the X server should use this.
1450 This code has a reasonably generic interface so that similar
1451 control registers on other processors can be easily supported
1454 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1455 Registers (ARRs) which provide a similar functionality to MTRRs. For
1456 these, the ARRs are used to emulate the MTRRs.
1457 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1458 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1459 write-combining. All of these processors are supported by this code
1460 and it makes sense to say Y here if you have one of them.
1462 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1463 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1464 can lead to all sorts of problems, so it's good to say Y here.
1466 You can safely say Y even if your machine doesn't have MTRRs, you'll
1467 just add about 9 KB to your kernel.
1469 See <file:Documentation/x86/mtrr.txt> for more information.
1471 config MTRR_SANITIZER
1473 prompt "MTRR cleanup support"
1476 Convert MTRR layout from continuous to discrete, so X drivers can
1477 add writeback entries.
1479 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1480 The largest mtrr entry size for a continuous block can be set with
1485 config MTRR_SANITIZER_ENABLE_DEFAULT
1486 int "MTRR cleanup enable value (0-1)"
1489 depends on MTRR_SANITIZER
1491 Enable mtrr cleanup default value
1493 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1494 int "MTRR cleanup spare reg num (0-7)"
1497 depends on MTRR_SANITIZER
1499 mtrr cleanup spare entries default, it can be changed via
1500 mtrr_spare_reg_nr=N on the kernel command line.
1504 prompt "x86 PAT support" if EXPERT
1507 Use PAT attributes to setup page level cache control.
1509 PATs are the modern equivalents of MTRRs and are much more
1510 flexible than MTRRs.
1512 Say N here if you see bootup problems (boot crash, boot hang,
1513 spontaneous reboots) or a non-working video driver.
1517 config ARCH_USES_PG_UNCACHED
1523 prompt "x86 architectural random number generator" if EXPERT
1525 Enable the x86 architectural RDRAND instruction
1526 (Intel Bull Mountain technology) to generate random numbers.
1527 If supported, this is a high bandwidth, cryptographically
1528 secure hardware random number generator.
1532 prompt "Supervisor Mode Access Prevention" if EXPERT
1534 Supervisor Mode Access Prevention (SMAP) is a security
1535 feature in newer Intel processors. There is a small
1536 performance cost if this enabled and turned on; there is
1537 also a small increase in the kernel size if this is enabled.
1542 bool "EFI runtime service support"
1545 This enables the kernel to use EFI runtime services that are
1546 available (such as the EFI variable services).
1548 This option is only useful on systems that have EFI firmware.
1549 In addition, you should use the latest ELILO loader available
1550 at <http://elilo.sourceforge.net> in order to take advantage
1551 of EFI runtime services. However, even with this option, the
1552 resultant kernel should continue to boot on existing non-EFI
1556 bool "EFI stub support"
1559 This kernel feature allows a bzImage to be loaded directly
1560 by EFI firmware without the use of a bootloader.
1562 See Documentation/x86/efi-stub.txt for more information.
1566 prompt "Enable seccomp to safely compute untrusted bytecode"
1568 This kernel feature is useful for number crunching applications
1569 that may need to compute untrusted bytecode during their
1570 execution. By using pipes or other transports made available to
1571 the process as file descriptors supporting the read/write
1572 syscalls, it's possible to isolate those applications in
1573 their own address space using seccomp. Once seccomp is
1574 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1575 and the task is only allowed to execute a few safe syscalls
1576 defined by each seccomp mode.
1578 If unsure, say Y. Only embedded should say N here.
1580 config CC_STACKPROTECTOR
1581 bool "Enable -fstack-protector buffer overflow detection"
1583 This option turns on the -fstack-protector GCC feature. This
1584 feature puts, at the beginning of functions, a canary value on
1585 the stack just before the return address, and validates
1586 the value just before actually returning. Stack based buffer
1587 overflows (that need to overwrite this return address) now also
1588 overwrite the canary, which gets detected and the attack is then
1589 neutralized via a kernel panic.
1591 This feature requires gcc version 4.2 or above, or a distribution
1592 gcc with the feature backported. Older versions are automatically
1593 detected and for those versions, this configuration option is
1594 ignored. (and a warning is printed during bootup)
1596 source kernel/Kconfig.hz
1599 bool "kexec system call"
1601 kexec is a system call that implements the ability to shutdown your
1602 current kernel, and to start another kernel. It is like a reboot
1603 but it is independent of the system firmware. And like a reboot
1604 you can start any kernel with it, not just Linux.
1606 The name comes from the similarity to the exec system call.
1608 It is an ongoing process to be certain the hardware in a machine
1609 is properly shutdown, so do not be surprised if this code does not
1610 initially work for you. It may help to enable device hotplugging
1611 support. As of this writing the exact hardware interface is
1612 strongly in flux, so no good recommendation can be made.
1615 bool "kernel crash dumps"
1616 depends on X86_64 || (X86_32 && HIGHMEM)
1618 Generate crash dump after being started by kexec.
1619 This should be normally only set in special crash dump kernels
1620 which are loaded in the main kernel with kexec-tools into
1621 a specially reserved region and then later executed after
1622 a crash by kdump/kexec. The crash dump kernel must be compiled
1623 to a memory address not used by the main kernel or BIOS using
1624 PHYSICAL_START, or it must be built as a relocatable image
1625 (CONFIG_RELOCATABLE=y).
1626 For more details see Documentation/kdump/kdump.txt
1629 bool "kexec jump (EXPERIMENTAL)"
1630 depends on EXPERIMENTAL
1631 depends on KEXEC && HIBERNATION
1633 Jump between original kernel and kexeced kernel and invoke
1634 code in physical address mode via KEXEC
1636 config PHYSICAL_START
1637 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1640 This gives the physical address where the kernel is loaded.
1642 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1643 bzImage will decompress itself to above physical address and
1644 run from there. Otherwise, bzImage will run from the address where
1645 it has been loaded by the boot loader and will ignore above physical
1648 In normal kdump cases one does not have to set/change this option
1649 as now bzImage can be compiled as a completely relocatable image
1650 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1651 address. This option is mainly useful for the folks who don't want
1652 to use a bzImage for capturing the crash dump and want to use a
1653 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1654 to be specifically compiled to run from a specific memory area
1655 (normally a reserved region) and this option comes handy.
1657 So if you are using bzImage for capturing the crash dump,
1658 leave the value here unchanged to 0x1000000 and set
1659 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1660 for capturing the crash dump change this value to start of
1661 the reserved region. In other words, it can be set based on
1662 the "X" value as specified in the "crashkernel=YM@XM"
1663 command line boot parameter passed to the panic-ed
1664 kernel. Please take a look at Documentation/kdump/kdump.txt
1665 for more details about crash dumps.
1667 Usage of bzImage for capturing the crash dump is recommended as
1668 one does not have to build two kernels. Same kernel can be used
1669 as production kernel and capture kernel. Above option should have
1670 gone away after relocatable bzImage support is introduced. But it
1671 is present because there are users out there who continue to use
1672 vmlinux for dump capture. This option should go away down the
1675 Don't change this unless you know what you are doing.
1678 bool "Build a relocatable kernel"
1681 This builds a kernel image that retains relocation information
1682 so it can be loaded someplace besides the default 1MB.
1683 The relocations tend to make the kernel binary about 10% larger,
1684 but are discarded at runtime.
1686 One use is for the kexec on panic case where the recovery kernel
1687 must live at a different physical address than the primary
1690 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1691 it has been loaded at and the compile time physical address
1692 (CONFIG_PHYSICAL_START) is ignored.
1694 # Relocation on x86-32 needs some additional build support
1695 config X86_NEED_RELOCS
1697 depends on X86_32 && RELOCATABLE
1699 config PHYSICAL_ALIGN
1700 hex "Alignment value to which kernel should be aligned" if X86_32
1702 range 0x2000 0x1000000
1704 This value puts the alignment restrictions on physical address
1705 where kernel is loaded and run from. Kernel is compiled for an
1706 address which meets above alignment restriction.
1708 If bootloader loads the kernel at a non-aligned address and
1709 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1710 address aligned to above value and run from there.
1712 If bootloader loads the kernel at a non-aligned address and
1713 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1714 load address and decompress itself to the address it has been
1715 compiled for and run from there. The address for which kernel is
1716 compiled already meets above alignment restrictions. Hence the
1717 end result is that kernel runs from a physical address meeting
1718 above alignment restrictions.
1720 Don't change this unless you know what you are doing.
1723 bool "Support for hot-pluggable CPUs"
1724 depends on SMP && HOTPLUG
1726 Say Y here to allow turning CPUs off and on. CPUs can be
1727 controlled through /sys/devices/system/cpu.
1728 ( Note: power management support will enable this option
1729 automatically on SMP systems. )
1730 Say N if you want to disable CPU hotplug.
1734 prompt "Compat VDSO support"
1735 depends on X86_32 || IA32_EMULATION
1737 Map the 32-bit VDSO to the predictable old-style address too.
1739 Say N here if you are running a sufficiently recent glibc
1740 version (2.3.3 or later), to remove the high-mapped
1741 VDSO mapping and to exclusively use the randomized VDSO.
1746 bool "Built-in kernel command line"
1748 Allow for specifying boot arguments to the kernel at
1749 build time. On some systems (e.g. embedded ones), it is
1750 necessary or convenient to provide some or all of the
1751 kernel boot arguments with the kernel itself (that is,
1752 to not rely on the boot loader to provide them.)
1754 To compile command line arguments into the kernel,
1755 set this option to 'Y', then fill in the
1756 the boot arguments in CONFIG_CMDLINE.
1758 Systems with fully functional boot loaders (i.e. non-embedded)
1759 should leave this option set to 'N'.
1762 string "Built-in kernel command string"
1763 depends on CMDLINE_BOOL
1766 Enter arguments here that should be compiled into the kernel
1767 image and used at boot time. If the boot loader provides a
1768 command line at boot time, it is appended to this string to
1769 form the full kernel command line, when the system boots.
1771 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1772 change this behavior.
1774 In most cases, the command line (whether built-in or provided
1775 by the boot loader) should specify the device for the root
1778 config CMDLINE_OVERRIDE
1779 bool "Built-in command line overrides boot loader arguments"
1780 depends on CMDLINE_BOOL
1782 Set this option to 'Y' to have the kernel ignore the boot loader
1783 command line, and use ONLY the built-in command line.
1785 This is used to work around broken boot loaders. This should
1786 be set to 'N' under normal conditions.
1790 config ARCH_ENABLE_MEMORY_HOTPLUG
1792 depends on X86_64 || (X86_32 && HIGHMEM)
1794 config ARCH_ENABLE_MEMORY_HOTREMOVE
1796 depends on MEMORY_HOTPLUG
1798 config USE_PERCPU_NUMA_NODE_ID
1802 menu "Power management and ACPI options"
1804 config ARCH_HIBERNATION_HEADER
1806 depends on X86_64 && HIBERNATION
1808 source "kernel/power/Kconfig"
1810 source "drivers/acpi/Kconfig"
1812 source "drivers/sfi/Kconfig"
1819 tristate "APM (Advanced Power Management) BIOS support"
1820 depends on X86_32 && PM_SLEEP
1822 APM is a BIOS specification for saving power using several different
1823 techniques. This is mostly useful for battery powered laptops with
1824 APM compliant BIOSes. If you say Y here, the system time will be
1825 reset after a RESUME operation, the /proc/apm device will provide
1826 battery status information, and user-space programs will receive
1827 notification of APM "events" (e.g. battery status change).
1829 If you select "Y" here, you can disable actual use of the APM
1830 BIOS by passing the "apm=off" option to the kernel at boot time.
1832 Note that the APM support is almost completely disabled for
1833 machines with more than one CPU.
1835 In order to use APM, you will need supporting software. For location
1836 and more information, read <file:Documentation/power/apm-acpi.txt>
1837 and the Battery Powered Linux mini-HOWTO, available from
1838 <http://www.tldp.org/docs.html#howto>.
1840 This driver does not spin down disk drives (see the hdparm(8)
1841 manpage ("man 8 hdparm") for that), and it doesn't turn off
1842 VESA-compliant "green" monitors.
1844 This driver does not support the TI 4000M TravelMate and the ACER
1845 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1846 desktop machines also don't have compliant BIOSes, and this driver
1847 may cause those machines to panic during the boot phase.
1849 Generally, if you don't have a battery in your machine, there isn't
1850 much point in using this driver and you should say N. If you get
1851 random kernel OOPSes or reboots that don't seem to be related to
1852 anything, try disabling/enabling this option (or disabling/enabling
1855 Some other things you should try when experiencing seemingly random,
1858 1) make sure that you have enough swap space and that it is
1860 2) pass the "no-hlt" option to the kernel
1861 3) switch on floating point emulation in the kernel and pass
1862 the "no387" option to the kernel
1863 4) pass the "floppy=nodma" option to the kernel
1864 5) pass the "mem=4M" option to the kernel (thereby disabling
1865 all but the first 4 MB of RAM)
1866 6) make sure that the CPU is not over clocked.
1867 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1868 8) disable the cache from your BIOS settings
1869 9) install a fan for the video card or exchange video RAM
1870 10) install a better fan for the CPU
1871 11) exchange RAM chips
1872 12) exchange the motherboard.
1874 To compile this driver as a module, choose M here: the
1875 module will be called apm.
1879 config APM_IGNORE_USER_SUSPEND
1880 bool "Ignore USER SUSPEND"
1882 This option will ignore USER SUSPEND requests. On machines with a
1883 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1884 series notebooks, it is necessary to say Y because of a BIOS bug.
1886 config APM_DO_ENABLE
1887 bool "Enable PM at boot time"
1889 Enable APM features at boot time. From page 36 of the APM BIOS
1890 specification: "When disabled, the APM BIOS does not automatically
1891 power manage devices, enter the Standby State, enter the Suspend
1892 State, or take power saving steps in response to CPU Idle calls."
1893 This driver will make CPU Idle calls when Linux is idle (unless this
1894 feature is turned off -- see "Do CPU IDLE calls", below). This
1895 should always save battery power, but more complicated APM features
1896 will be dependent on your BIOS implementation. You may need to turn
1897 this option off if your computer hangs at boot time when using APM
1898 support, or if it beeps continuously instead of suspending. Turn
1899 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1900 T400CDT. This is off by default since most machines do fine without
1904 bool "Make CPU Idle calls when idle"
1906 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1907 On some machines, this can activate improved power savings, such as
1908 a slowed CPU clock rate, when the machine is idle. These idle calls
1909 are made after the idle loop has run for some length of time (e.g.,
1910 333 mS). On some machines, this will cause a hang at boot time or
1911 whenever the CPU becomes idle. (On machines with more than one CPU,
1912 this option does nothing.)
1914 config APM_DISPLAY_BLANK
1915 bool "Enable console blanking using APM"
1917 Enable console blanking using the APM. Some laptops can use this to
1918 turn off the LCD backlight when the screen blanker of the Linux
1919 virtual console blanks the screen. Note that this is only used by
1920 the virtual console screen blanker, and won't turn off the backlight
1921 when using the X Window system. This also doesn't have anything to
1922 do with your VESA-compliant power-saving monitor. Further, this
1923 option doesn't work for all laptops -- it might not turn off your
1924 backlight at all, or it might print a lot of errors to the console,
1925 especially if you are using gpm.
1927 config APM_ALLOW_INTS
1928 bool "Allow interrupts during APM BIOS calls"
1930 Normally we disable external interrupts while we are making calls to
1931 the APM BIOS as a measure to lessen the effects of a badly behaving
1932 BIOS implementation. The BIOS should reenable interrupts if it
1933 needs to. Unfortunately, some BIOSes do not -- especially those in
1934 many of the newer IBM Thinkpads. If you experience hangs when you
1935 suspend, try setting this to Y. Otherwise, say N.
1939 source "drivers/cpufreq/Kconfig"
1941 source "drivers/cpuidle/Kconfig"
1943 source "drivers/idle/Kconfig"
1948 menu "Bus options (PCI etc.)"
1953 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1955 Find out whether you have a PCI motherboard. PCI is the name of a
1956 bus system, i.e. the way the CPU talks to the other stuff inside
1957 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1958 VESA. If you have PCI, say Y, otherwise N.
1961 prompt "PCI access mode"
1962 depends on X86_32 && PCI
1965 On PCI systems, the BIOS can be used to detect the PCI devices and
1966 determine their configuration. However, some old PCI motherboards
1967 have BIOS bugs and may crash if this is done. Also, some embedded
1968 PCI-based systems don't have any BIOS at all. Linux can also try to
1969 detect the PCI hardware directly without using the BIOS.
1971 With this option, you can specify how Linux should detect the
1972 PCI devices. If you choose "BIOS", the BIOS will be used,
1973 if you choose "Direct", the BIOS won't be used, and if you
1974 choose "MMConfig", then PCI Express MMCONFIG will be used.
1975 If you choose "Any", the kernel will try MMCONFIG, then the
1976 direct access method and falls back to the BIOS if that doesn't
1977 work. If unsure, go with the default, which is "Any".
1982 config PCI_GOMMCONFIG
1999 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2001 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2004 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2008 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2012 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2016 depends on PCI && XEN
2024 bool "Support mmconfig PCI config space access"
2025 depends on X86_64 && PCI && ACPI
2027 config PCI_CNB20LE_QUIRK
2028 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2029 depends on PCI && EXPERIMENTAL
2031 Read the PCI windows out of the CNB20LE host bridge. This allows
2032 PCI hotplug to work on systems with the CNB20LE chipset which do
2035 There's no public spec for this chipset, and this functionality
2036 is known to be incomplete.
2038 You should say N unless you know you need this.
2040 source "drivers/pci/pcie/Kconfig"
2042 source "drivers/pci/Kconfig"
2044 # x86_64 have no ISA slots, but can have ISA-style DMA.
2046 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2049 Enables ISA-style DMA support for devices requiring such controllers.
2057 Find out whether you have ISA slots on your motherboard. ISA is the
2058 name of a bus system, i.e. the way the CPU talks to the other stuff
2059 inside your box. Other bus systems are PCI, EISA, MicroChannel
2060 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2061 newer boards don't support it. If you have ISA, say Y, otherwise N.
2067 The Extended Industry Standard Architecture (EISA) bus was
2068 developed as an open alternative to the IBM MicroChannel bus.
2070 The EISA bus provided some of the features of the IBM MicroChannel
2071 bus while maintaining backward compatibility with cards made for
2072 the older ISA bus. The EISA bus saw limited use between 1988 and
2073 1995 when it was made obsolete by the PCI bus.
2075 Say Y here if you are building a kernel for an EISA-based machine.
2079 source "drivers/eisa/Kconfig"
2082 tristate "NatSemi SCx200 support"
2084 This provides basic support for National Semiconductor's
2085 (now AMD's) Geode processors. The driver probes for the
2086 PCI-IDs of several on-chip devices, so its a good dependency
2087 for other scx200_* drivers.
2089 If compiled as a module, the driver is named scx200.
2091 config SCx200HR_TIMER
2092 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2096 This driver provides a clocksource built upon the on-chip
2097 27MHz high-resolution timer. Its also a workaround for
2098 NSC Geode SC-1100's buggy TSC, which loses time when the
2099 processor goes idle (as is done by the scheduler). The
2100 other workaround is idle=poll boot option.
2103 bool "One Laptop Per Child support"
2110 Add support for detecting the unique features of the OLPC
2114 bool "OLPC XO-1 Power Management"
2115 depends on OLPC && MFD_CS5535 && PM_SLEEP
2118 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2121 bool "OLPC XO-1 Real Time Clock"
2122 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2124 Add support for the XO-1 real time clock, which can be used as a
2125 programmable wakeup source.
2128 bool "OLPC XO-1 SCI extras"
2129 depends on OLPC && OLPC_XO1_PM
2134 Add support for SCI-based features of the OLPC XO-1 laptop:
2135 - EC-driven system wakeups
2139 - AC adapter status updates
2140 - Battery status updates
2142 config OLPC_XO15_SCI
2143 bool "OLPC XO-1.5 SCI extras"
2144 depends on OLPC && ACPI
2147 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2148 - EC-driven system wakeups
2149 - AC adapter status updates
2150 - Battery status updates
2153 bool "PCEngines ALIX System Support (LED setup)"
2156 This option enables system support for the PCEngines ALIX.
2157 At present this just sets up LEDs for GPIO control on
2158 ALIX2/3/6 boards. However, other system specific setup should
2161 Note: You must still enable the drivers for GPIO and LED support
2162 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2164 Note: You have to set alix.force=1 for boards with Award BIOS.
2167 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2170 This option enables system support for the Soekris Engineering net5501.
2173 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2177 This option enables system support for the Traverse Technologies GEOS.
2183 depends on CPU_SUP_AMD && PCI
2185 source "drivers/pcmcia/Kconfig"
2187 source "drivers/pci/hotplug/Kconfig"
2190 bool "RapidIO support"
2194 If you say Y here, the kernel will include drivers and
2195 infrastructure code to support RapidIO interconnect devices.
2197 source "drivers/rapidio/Kconfig"
2202 menu "Executable file formats / Emulations"
2204 source "fs/Kconfig.binfmt"
2206 config IA32_EMULATION
2207 bool "IA32 Emulation"
2209 select COMPAT_BINFMT_ELF
2212 Include code to run legacy 32-bit programs under a
2213 64-bit kernel. You should likely turn this on, unless you're
2214 100% sure that you don't have any 32-bit programs left.
2217 tristate "IA32 a.out support"
2218 depends on IA32_EMULATION
2220 Support old a.out binaries in the 32bit emulation.
2223 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2224 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2226 Include code to run binaries for the x32 native 32-bit ABI
2227 for 64-bit processors. An x32 process gets access to the
2228 full 64-bit register file and wide data path while leaving
2229 pointers at 32 bits for smaller memory footprint.
2231 You will need a recent binutils (2.22 or later) with
2232 elf32_x86_64 support enabled to compile a kernel with this
2237 depends on IA32_EMULATION || X86_X32
2238 select ARCH_WANT_OLD_COMPAT_IPC
2241 config COMPAT_FOR_U64_ALIGNMENT
2244 config SYSVIPC_COMPAT
2256 config HAVE_ATOMIC_IOMAP
2260 config HAVE_TEXT_POKE_SMP
2262 select STOP_MACHINE if SMP
2264 config X86_DEV_DMA_OPS
2266 depends on X86_64 || STA2X11
2268 config X86_DMA_REMAP
2272 source "net/Kconfig"
2274 source "drivers/Kconfig"
2276 source "drivers/firmware/Kconfig"
2280 source "arch/x86/Kconfig.debug"
2282 source "security/Kconfig"
2284 source "crypto/Kconfig"
2286 source "arch/x86/kvm/Kconfig"
2288 source "lib/Kconfig"