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
11 select CLKSRC_I8253 if !XEN
19 select HAVE_AOUT if X86_32
20 select HAVE_UNSTABLE_SCHED_CLOCK
23 select HAVE_PCSPKR_PLATFORM if !XEN_UNPRIVILEGED_GUEST
24 select HAVE_PERF_EVENTS
26 select HAVE_IOREMAP_PROT
29 select HAVE_MEMBLOCK_NODE_MAP
30 select ARCH_DISCARD_MEMBLOCK
31 select ARCH_WANT_OPTIONAL_GPIOLIB
32 select ARCH_WANT_FRAME_POINTERS
34 select HAVE_KRETPROBES
36 select HAVE_FTRACE_MCOUNT_RECORD
37 select HAVE_C_RECORDMCOUNT
38 select HAVE_DYNAMIC_FTRACE
39 select HAVE_FUNCTION_TRACER
40 select HAVE_FUNCTION_GRAPH_TRACER
41 select HAVE_FUNCTION_GRAPH_FP_TEST
42 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
43 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
44 select HAVE_SYSCALL_TRACEPOINTS
45 select HAVE_KVM if !XEN
46 select HAVE_ARCH_KGDB if !XEN
47 select HAVE_ARCH_TRACEHOOK
48 select HAVE_GENERIC_DMA_COHERENT if X86_32
49 select HAVE_EFFICIENT_UNALIGNED_ACCESS
50 select USER_STACKTRACE_SUPPORT
51 select HAVE_REGS_AND_STACK_ACCESS_API
52 select HAVE_DMA_API_DEBUG
53 select HAVE_KERNEL_GZIP
54 select HAVE_KERNEL_BZIP2 if !XEN
55 select HAVE_KERNEL_LZMA if !XEN
56 select HAVE_KERNEL_XZ if !XEN
57 select HAVE_KERNEL_LZO if !XEN
58 select HAVE_HW_BREAKPOINT
59 select HAVE_MIXED_BREAKPOINTS_REGS
61 select HAVE_PERF_EVENTS_NMI if !XEN
63 select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386
64 select HAVE_CMPXCHG_LOCAL if !M386
65 select HAVE_CMPXCHG_DOUBLE
66 select HAVE_ARCH_KMEMCHECK
67 select HAVE_USER_RETURN_NOTIFIER
68 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
69 select HAVE_ARCH_JUMP_LABEL
70 select HAVE_TEXT_POKE_SMP
71 select HAVE_GENERIC_HARDIRQS
72 select HAVE_SPARSE_IRQ
74 select GENERIC_FIND_FIRST_BIT
75 select GENERIC_IRQ_PROBE
76 select GENERIC_PENDING_IRQ if SMP
77 select GENERIC_IRQ_SHOW
78 select GENERIC_CLOCKEVENTS_MIN_ADJUST
79 select IRQ_FORCED_THREADING
80 select USE_GENERIC_SMP_HELPERS if SMP
81 select HAVE_BPF_JIT if (X86_64 && NET)
82 select CLKEVT_I8253 if !XEN
83 select ARCH_HAVE_NMI_SAFE_CMPXCHG
86 config INSTRUCTION_DECODER
87 def_bool (KPROBES || PERF_EVENTS)
91 default "elf32-i386" if X86_32
92 default "elf64-x86-64" if X86_64
96 default "arch/x86/configs/i386_defconfig" if X86_32
97 default "arch/x86/configs/x86_64_defconfig" if X86_64
99 config GENERIC_CMOS_UPDATE
102 config CLOCKSOURCE_WATCHDOG
106 config GENERIC_CLOCKEVENTS
109 config ARCH_CLOCKSOURCE_DATA
111 depends on X86_64 && !XEN
113 config GENERIC_CLOCKEVENTS_BROADCAST
115 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
118 config LOCKDEP_SUPPORT
121 config STACKTRACE_SUPPORT
124 config HAVE_LATENCYTOP_SUPPORT
133 config NEED_DMA_MAP_STATE
134 def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB)
136 config NEED_SG_DMA_LENGTH
139 config GENERIC_ISA_DMA
145 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
147 config GENERIC_BUG_RELATIVE_POINTERS
150 config GENERIC_HWEIGHT
156 config ARCH_MAY_HAVE_PC_FDC
159 config RWSEM_GENERIC_SPINLOCK
162 config RWSEM_XCHGADD_ALGORITHM
165 config ARCH_HAS_CPU_IDLE_WAIT
168 config GENERIC_CALIBRATE_DELAY
171 config GENERIC_TIME_VSYSCALL
175 config ARCH_HAS_CPU_RELAX
178 config ARCH_HAS_DEFAULT_IDLE
181 config ARCH_HAS_CACHE_LINE_SIZE
184 config ARCH_HAS_CPU_AUTOPROBE
187 config HAVE_SETUP_PER_CPU_AREA
190 config NEED_PER_CPU_EMBED_FIRST_CHUNK
193 config NEED_PER_CPU_PAGE_FIRST_CHUNK
196 config ARCH_HIBERNATION_POSSIBLE
200 config ARCH_SUSPEND_POSSIBLE
211 config ARCH_SUPPORTS_OPTIMIZED_INLINING
214 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
217 config HAVE_INTEL_TXT
219 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
223 depends on X86_32 && SMP
227 depends on X86_64 && SMP
231 depends on SMP && !XEN
241 config X86_32_LAZY_GS
243 depends on X86_32 && !CC_STACKPROTECTOR
245 config ARCH_HWEIGHT_CFLAGS
247 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
248 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
253 config ARCH_CPU_PROBE_RELEASE
255 depends on HOTPLUG_CPU && !XEN
257 source "init/Kconfig"
258 source "kernel/Kconfig.freezer"
260 menu "Processor type and features"
263 bool "DMA memory allocation support" if EXPERT
266 DMA memory allocation support allows devices with less than 32-bit
267 addressing to allocate within the first 16MB of address space.
268 Disable if no such devices will be used.
272 source "kernel/time/Kconfig"
275 bool "Symmetric multi-processing support"
277 This enables support for systems with more than one CPU. If you have
278 a system with only one CPU, like most personal computers, say N. If
279 you have a system with more than one CPU, say Y.
281 If you say N here, the kernel will run on single and multiprocessor
282 machines, but will use only one CPU of a multiprocessor machine. If
283 you say Y here, the kernel will run on many, but not all,
284 singleprocessor machines. On a singleprocessor machine, the kernel
285 will run faster if you say N here.
287 Note that if you say Y here and choose architecture "586" or
288 "Pentium" under "Processor family", the kernel will not work on 486
289 architectures. Similarly, multiprocessor kernels for the "PPro"
290 architecture may not work on all Pentium based boards.
292 People using multiprocessor machines who say Y here should also say
293 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
294 Management" code will be disabled if you say Y here.
296 See also <file:Documentation/x86/i386/IO-APIC.txt>,
297 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
298 <http://www.tldp.org/docs.html#howto>.
300 If you don't know what to do here, say N.
303 bool "Support x2apic"
304 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
306 This enables x2apic support on CPUs that have this feature.
308 This allows 32-bit apic IDs (so it can support very large systems),
309 and accesses the local apic via MSRs not via mmio.
311 If you don't know what to do here, say N.
314 bool "Enable MPS table" if ACPI
316 depends on X86_LOCAL_APIC
318 For old smp systems that do not have proper acpi support. Newer systems
319 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
322 bool "Xen-compatible"
327 Choose this option if you plan to run this kernel on top of the
331 bool "Support for big SMP systems with more than 8 CPUs"
332 depends on X86_32 && SMP && !XEN
334 This option is needed for the systems that have more than 8 CPUs
337 config X86_EXTENDED_PLATFORM
338 bool "Support for extended (non-PC) x86 platforms"
341 If you disable this option then the kernel will only support
342 standard PC platforms. (which covers the vast majority of
345 If you enable this option then you'll be able to select support
346 for the following (non-PC) 32 bit x86 platforms:
350 SGI 320/540 (Visual Workstation)
351 Summit/EXA (IBM x440)
352 Unisys ES7000 IA32 series
353 Moorestown MID devices
355 If you have one of these systems, or if you want to build a
356 generic distribution kernel, say Y here - otherwise say N.
360 bool "Enable Xen compatible kernel"
364 This option will compile a kernel compatible with Xen hypervisor
367 config X86_EXTENDED_PLATFORM
368 bool "Support for extended (non-PC) x86 platforms"
371 If you disable this option then the kernel will only support
372 standard PC platforms. (which covers the vast majority of
375 If you enable this option then you'll be able to select support
376 for the following (non-PC) 64 bit x86 platforms:
381 If you have one of these systems, or if you want to build a
382 generic distribution kernel, say Y here - otherwise say N.
384 # This is an alphabetically sorted list of 64 bit extended platforms
385 # Please maintain the alphabetic order if and when there are additions
387 bool "Numascale NumaChip"
389 depends on X86_EXTENDED_PLATFORM
392 depends on X86_X2APIC
394 Adds support for Numascale NumaChip large-SMP systems. Needed to
395 enable more than ~168 cores.
396 If you don't have one of these, you should say N here.
400 select PARAVIRT_GUEST
402 depends on X86_64 && PCI
403 depends on X86_EXTENDED_PLATFORM
405 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
406 supposed to run on these EM64T-based machines. Only choose this option
407 if you have one of these machines.
410 bool "SGI Ultraviolet"
412 depends on X86_EXTENDED_PLATFORM
414 depends on X86_X2APIC
416 This option is needed in order to support SGI Ultraviolet systems.
417 If you don't have one of these, you should say N here.
419 # Following is an alphabetically sorted list of 32 bit extended platforms
420 # Please maintain the alphabetic order if and when there are additions
423 bool "CE4100 TV platform"
425 depends on PCI_GODIRECT
427 depends on X86_EXTENDED_PLATFORM
428 select X86_REBOOTFIXUPS
430 select OF_EARLY_FLATTREE
432 Select for the Intel CE media processor (CE4100) SOC.
433 This option compiles in support for the CE4100 SOC for settop
434 boxes and media devices.
436 config X86_WANT_INTEL_MID
437 bool "Intel MID platform support"
439 depends on X86_EXTENDED_PLATFORM
441 Select to build a kernel capable of supporting Intel MID platform
442 systems which do not have the PCI legacy interfaces (Moorestown,
443 Medfield). If you are building for a PC class system say N here.
445 if X86_WANT_INTEL_MID
451 bool "Moorestown MID platform"
454 depends on X86_IO_APIC
462 select X86_PLATFORM_DEVICES
464 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
465 Internet Device(MID) platform. Moorestown consists of two chips:
466 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
467 Unlike standard x86 PCs, Moorestown does not have many legacy devices
468 nor standard legacy replacement devices/features. e.g. Moorestown does
469 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
472 bool "Medfield MID platform"
475 depends on X86_IO_APIC
483 select X86_PLATFORM_DEVICES
485 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
486 Internet Device(MID) platform.
487 Unlike standard x86 PCs, Medfield does not have many legacy devices
488 nor standard legacy replacement devices/features. e.g. Medfield does
489 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
494 bool "RDC R-321x SoC"
496 depends on X86_EXTENDED_PLATFORM
498 select X86_REBOOTFIXUPS
500 This option is needed for RDC R-321x system-on-chip, also known
502 If you don't have one of these chips, you should say N here.
504 config X86_32_NON_STANDARD
505 bool "Support non-standard 32-bit SMP architectures"
506 depends on X86_32 && SMP
507 depends on X86_EXTENDED_PLATFORM
509 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
510 subarchitectures. It is intended for a generic binary kernel.
511 if you select them all, kernel will probe it one by one. and will
514 # Alphabetically sorted list of Non standard 32 bit platforms
517 bool "NUMAQ (IBM/Sequent)"
518 depends on X86_32_NON_STANDARD
523 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
524 NUMA multiquad box. This changes the way that processors are
525 bootstrapped, and uses Clustered Logical APIC addressing mode instead
526 of Flat Logical. You will need a new lynxer.elf file to flash your
527 firmware with - send email to <Martin.Bligh@us.ibm.com>.
529 config X86_SUPPORTS_MEMORY_FAILURE
531 # MCE code calls memory_failure():
533 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
534 depends on !X86_NUMAQ
535 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
536 depends on X86_64 || !SPARSEMEM
537 select ARCH_SUPPORTS_MEMORY_FAILURE
540 bool "SGI 320/540 (Visual Workstation)"
541 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
542 depends on X86_32_NON_STANDARD
544 The SGI Visual Workstation series is an IA32-based workstation
545 based on SGI systems chips with some legacy PC hardware attached.
547 Say Y here to create a kernel to run on the SGI 320 or 540.
549 A kernel compiled for the Visual Workstation will run on general
550 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
553 bool "Summit/EXA (IBM x440)"
554 depends on X86_32_NON_STANDARD
556 This option is needed for IBM systems that use the Summit/EXA chipset.
557 In particular, it is needed for the x440.
560 bool "Unisys ES7000 IA32 series"
561 depends on X86_32_NON_STANDARD && X86_BIGSMP
563 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
564 supposed to run on an IA32-based Unisys ES7000 system.
567 tristate "Eurobraille/Iris poweroff module"
568 depends on X86_32 && !XEN
570 The Iris machines from EuroBraille do not have APM or ACPI support
571 to shut themselves down properly. A special I/O sequence is
572 needed to do so, which is what this module does at
575 This is only for Iris machines from EuroBraille.
579 config SCHED_OMIT_FRAME_POINTER
581 prompt "Single-depth WCHAN output"
582 depends on X86 && !STACK_UNWIND
584 Calculate simpler /proc/<PID>/wchan values. If this option
585 is disabled then wchan values will recurse back to the
586 caller function. This provides more accurate wchan values,
587 at the expense of slightly more scheduling overhead.
589 If in doubt, say "Y".
591 menuconfig PARAVIRT_GUEST
592 bool "Paravirtualized guest support"
595 Say Y here to get to see options related to running Linux under
596 various hypervisors. This option alone does not add any kernel code.
598 If you say N, all options in this submenu will be skipped and disabled.
602 config PARAVIRT_TIME_ACCOUNTING
603 bool "Paravirtual steal time accounting"
607 Select this option to enable fine granularity task steal time
608 accounting. Time spent executing other tasks in parallel with
609 the current vCPU is discounted from the vCPU power. To account for
610 that, there can be a small performance impact.
612 If in doubt, say N here.
614 source "arch/x86/xen/Kconfig"
617 bool "KVM paravirtualized clock"
619 select PARAVIRT_CLOCK
621 Turning on this option will allow you to run a paravirtualized clock
622 when running over the KVM hypervisor. Instead of relying on a PIT
623 (or probably other) emulation by the underlying device model, the host
624 provides the guest with timing infrastructure such as time of day, and
628 bool "KVM Guest support"
631 This option enables various optimizations for running under the KVM
634 source "arch/x86/lguest/Kconfig"
637 bool "Enable paravirtualization code"
639 This changes the kernel so it can modify itself when it is run
640 under a hypervisor, potentially improving performance significantly
641 over full virtualization. However, when run without a hypervisor
642 the kernel is theoretically slower and slightly larger.
644 config PARAVIRT_SPINLOCKS
645 bool "Paravirtualization layer for spinlocks"
646 depends on PARAVIRT && SMP && EXPERIMENTAL
648 Paravirtualized spinlocks allow a pvops backend to replace the
649 spinlock implementation with something virtualization-friendly
650 (for example, block the virtual CPU rather than spinning).
652 Unfortunately the downside is an up to 5% performance hit on
653 native kernels, with various workloads.
655 If you are unsure how to answer this question, answer N.
657 config PARAVIRT_CLOCK
662 config PARAVIRT_DEBUG
663 bool "paravirt-ops debugging"
664 depends on PARAVIRT && DEBUG_KERNEL
666 Enable to debug paravirt_ops internals. Specifically, BUG if
667 a paravirt_op is missing when it is called.
676 This option adds a kernel parameter 'memtest', which allows memtest
678 memtest=0, mean disabled; -- default
679 memtest=1, mean do 1 test pattern;
681 memtest=4, mean do 4 test patterns.
682 If you are unsure how to answer this question, answer N.
684 config X86_SUMMIT_NUMA
686 depends on X86_32 && NUMA && X86_32_NON_STANDARD
688 config X86_CYCLONE_TIMER
690 depends on X86_SUMMIT
692 source "arch/x86/Kconfig.cpu"
696 prompt "HPET Timer Support" if X86_32
699 Use the IA-PC HPET (High Precision Event Timer) to manage
700 time in preference to the PIT and RTC, if a HPET is
702 HPET is the next generation timer replacing legacy 8254s.
703 The HPET provides a stable time base on SMP
704 systems, unlike the TSC, but it is more expensive to access,
705 as it is off-chip. You can find the HPET spec at
706 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
708 You can safely choose Y here. However, HPET will only be
709 activated if the platform and the BIOS support this feature.
710 Otherwise the 8254 will be used for timing services.
712 Choose N to continue using the legacy 8254 timer.
714 config HPET_EMULATE_RTC
716 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
719 def_bool y if X86_INTEL_MID
720 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
722 depends on X86_INTEL_MID && SFI
724 APB timer is the replacement for 8254, HPET on X86 MID platforms.
725 The APBT provides a stable time base on SMP
726 systems, unlike the TSC, but it is more expensive to access,
727 as it is off-chip. APB timers are always running regardless of CPU
728 C states, they are used as per CPU clockevent device when possible.
730 # Mark as expert because too many people got it wrong.
731 # The code disables itself when not needed.
734 bool "Enable DMI scanning" if EXPERT
735 depends on !XEN_UNPRIVILEGED_GUEST
737 Enabled scanning of DMI to identify machine quirks. Say Y
738 here unless you have verified that your setup is not
739 affected by entries in the DMI blacklist. Required by PNP
743 bool "GART IOMMU support" if EXPERT
746 depends on X86_64 && PCI && AMD_NB && !X86_64_XEN
748 Support for full DMA access of devices with 32bit memory access only
749 on systems with more than 3GB. This is usually needed for USB,
750 sound, many IDE/SATA chipsets and some other devices.
751 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
752 based hardware IOMMU and a software bounce buffer based IOMMU used
753 on Intel systems and as fallback.
754 The code is only active when needed (enough memory and limited
755 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
759 bool "IBM Calgary IOMMU support"
761 depends on X86_64 && PCI && !X86_64_XEN && EXPERIMENTAL
763 Support for hardware IOMMUs in IBM's xSeries x366 and x460
764 systems. Needed to run systems with more than 3GB of memory
765 properly with 32-bit PCI devices that do not support DAC
766 (Double Address Cycle). Calgary also supports bus level
767 isolation, where all DMAs pass through the IOMMU. This
768 prevents them from going anywhere except their intended
769 destination. This catches hard-to-find kernel bugs and
770 mis-behaving drivers and devices that do not use the DMA-API
771 properly to set up their DMA buffers. The IOMMU can be
772 turned off at boot time with the iommu=off parameter.
773 Normally the kernel will make the right choice by itself.
776 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
778 prompt "Should Calgary be enabled by default?"
779 depends on CALGARY_IOMMU
781 Should Calgary be enabled by default? if you choose 'y', Calgary
782 will be used (if it exists). If you choose 'n', Calgary will not be
783 used even if it exists. If you choose 'n' and would like to use
784 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
787 # need this always selected by IOMMU for the VIA workaround
789 def_bool y if X86_64 || XEN
790 prompt "Software I/O TLB" if XEN_UNPRIVILEGED_GUEST && !XEN_PCIDEV_FRONTEND
792 Support for software bounce buffers used on x86-64 systems
793 which don't have a hardware IOMMU (e.g. the current generation
794 of Intel's x86-64 CPUs). Using this PCI devices which can only
795 access 32-bits of memory can be used on systems with more than
796 3 GB of memory. If unsure, say Y.
799 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
802 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
803 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
804 select CPUMASK_OFFSTACK
806 Enable maximum number of CPUS and NUMA Nodes for this architecture.
810 int "Maximum number of CPUs" if SMP && !MAXSMP
811 range 2 8 if SMP && X86_32 && !X86_BIGSMP && !X86_XEN
812 range 2 512 if SMP && !MAXSMP
814 default "4096" if MAXSMP
815 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
816 default "16" if X86_64_XEN
819 This allows you to specify the maximum number of CPUs which this
820 kernel will support. The maximum supported value is 512 and the
821 minimum value which makes sense is 2.
823 This is purely to save memory - each supported CPU adds
824 approximately eight kilobytes to the kernel image.
827 bool "SMT (Hyperthreading) scheduler support"
830 SMT scheduler support improves the CPU scheduler's decision making
831 when dealing with Intel Pentium 4 chips with HyperThreading at a
832 cost of slightly increased overhead in some places. If unsure say
837 prompt "Multi-core scheduler support"
840 Multi-core scheduler support improves the CPU scheduler's decision
841 making when dealing with multi-core CPU chips at a cost of slightly
842 increased overhead in some places. If unsure say N here.
844 config IRQ_TIME_ACCOUNTING
845 bool "Fine granularity task level IRQ time accounting"
848 Select this option to enable fine granularity task irq time
849 accounting. This is done by reading a timestamp on each
850 transitions between softirq and hardirq state, so there can be a
851 small performance impact.
853 If in doubt, say N here.
855 source "kernel/Kconfig.preempt"
858 bool "Local APIC support on uniprocessors"
859 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !XEN_UNPRIVILEGED_GUEST
861 A local APIC (Advanced Programmable Interrupt Controller) is an
862 integrated interrupt controller in the CPU. If you have a single-CPU
863 system which has a processor with a local APIC, you can say Y here to
864 enable and use it. If you say Y here even though your machine doesn't
865 have a local APIC, then the kernel will still run with no slowdown at
866 all. The local APIC supports CPU-generated self-interrupts (timer,
867 performance counters), and the NMI watchdog which detects hard
871 bool "IO-APIC support on uniprocessors"
872 depends on X86_UP_APIC
874 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
875 SMP-capable replacement for PC-style interrupt controllers. Most
876 SMP systems and many recent uniprocessor systems have one.
878 If you have a single-CPU system with an IO-APIC, you can say Y here
879 to use it. If you say Y here even though your machine doesn't have
880 an IO-APIC, then the kernel will still run with no slowdown at all.
882 config X86_LOCAL_APIC
884 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
885 depends on !XEN_UNPRIVILEGED_GUEST
889 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
890 depends on !XEN_UNPRIVILEGED_GUEST
892 config X86_VISWS_APIC
894 depends on X86_32 && X86_VISWS
896 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
897 bool "Reroute for broken boot IRQs"
898 depends on X86_IO_APIC && !XEN
900 This option enables a workaround that fixes a source of
901 spurious interrupts. This is recommended when threaded
902 interrupt handling is used on systems where the generation of
903 superfluous "boot interrupts" cannot be disabled.
905 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
906 entry in the chipset's IO-APIC is masked (as, e.g. the RT
907 kernel does during interrupt handling). On chipsets where this
908 boot IRQ generation cannot be disabled, this workaround keeps
909 the original IRQ line masked so that only the equivalent "boot
910 IRQ" is delivered to the CPUs. The workaround also tells the
911 kernel to set up the IRQ handler on the boot IRQ line. In this
912 way only one interrupt is delivered to the kernel. Otherwise
913 the spurious second interrupt may cause the kernel to bring
914 down (vital) interrupt lines.
916 Only affects "broken" chipsets. Interrupt sharing may be
917 increased on these systems.
920 bool "Machine Check / overheating reporting"
921 depends on !XEN_UNPRIVILEGED_GUEST
923 Machine Check support allows the processor to notify the
924 kernel if it detects a problem (e.g. overheating, data corruption).
925 The action the kernel takes depends on the severity of the problem,
926 ranging from warning messages to halting the machine.
930 prompt "Intel MCE features"
931 depends on X86_MCE && X86_LOCAL_APIC && !XEN
933 Additional support for intel specific MCE features such as
938 prompt "AMD MCE features"
939 depends on X86_MCE && X86_LOCAL_APIC && !XEN
941 Additional support for AMD specific MCE features such as
942 the DRAM Error Threshold.
944 config X86_ANCIENT_MCE
945 bool "Support for old Pentium 5 / WinChip machine checks"
946 depends on X86_32 && X86_MCE && !XEN
948 Include support for machine check handling on old Pentium 5 or WinChip
949 systems. These typically need to be enabled explicitely on the command
952 config X86_MCE_THRESHOLD
953 depends on X86_MCE_AMD || X86_MCE_INTEL
956 config X86_MCE_INJECT
958 tristate "Machine check injector support"
960 Provide support for injecting machine checks for testing purposes.
961 If you don't know what a machine check is and you don't do kernel
962 QA it is safe to say n.
966 depends on XEN && X86_MCE
968 config X86_THERMAL_VECTOR
970 depends on X86_MCE_INTEL
973 bool "Enable VM86 support" if EXPERT
977 This option is required by programs like DOSEMU to run 16-bit legacy
978 code on X86 processors. It also may be needed by software like
979 XFree86 to initialize some video cards via BIOS. Disabling this
980 option saves about 6k.
983 tristate "Toshiba Laptop support"
986 This adds a driver to safely access the System Management Mode of
987 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
988 not work on models with a Phoenix BIOS. The System Management Mode
989 is used to set the BIOS and power saving options on Toshiba portables.
991 For information on utilities to make use of this driver see the
992 Toshiba Linux utilities web site at:
993 <http://www.buzzard.org.uk/toshiba/>.
995 Say Y if you intend to run this kernel on a Toshiba portable.
999 tristate "Dell laptop support"
1002 This adds a driver to safely access the System Management Mode
1003 of the CPU on the Dell Inspiron 8000. The System Management Mode
1004 is used to read cpu temperature and cooling fan status and to
1005 control the fans on the I8K portables.
1007 This driver has been tested only on the Inspiron 8000 but it may
1008 also work with other Dell laptops. You can force loading on other
1009 models by passing the parameter `force=1' to the module. Use at
1012 For information on utilities to make use of this driver see the
1013 I8K Linux utilities web site at:
1014 <http://people.debian.org/~dz/i8k/>
1016 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1019 config X86_REBOOTFIXUPS
1020 bool "Enable X86 board specific fixups for reboot"
1021 depends on X86_32 && !XEN
1023 This enables chipset and/or board specific fixups to be done
1024 in order to get reboot to work correctly. This is only needed on
1025 some combinations of hardware and BIOS. The symptom, for which
1026 this config is intended, is when reboot ends with a stalled/hung
1029 Currently, the only fixup is for the Geode machines using
1030 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1032 Say Y if you want to enable the fixup. Currently, it's safe to
1033 enable this option even if you don't need it.
1037 tristate "/dev/cpu/microcode - microcode support"
1038 depends on !XEN_UNPRIVILEGED_GUEST
1041 If you say Y here, you will be able to update the microcode on
1042 certain Intel and AMD processors. The Intel support is for the
1043 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
1044 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
1045 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
1046 You will obviously need the actual microcode binary data itself
1047 which is not shipped with the Linux kernel.
1049 This option selects the general module only, you need to select
1050 at least one vendor specific module as well.
1052 To compile this driver as a module, choose M here: the
1053 module will be called microcode.
1055 config MICROCODE_INTEL
1056 bool "Intel microcode patch loading support"
1057 depends on MICROCODE && !XEN
1061 This options enables microcode patch loading support for Intel
1064 For latest news and information on obtaining all the required
1065 Intel ingredients for this driver, check:
1066 <http://www.urbanmyth.org/microcode/>.
1068 config MICROCODE_AMD
1069 bool "AMD microcode patch loading support"
1070 depends on MICROCODE && !XEN
1073 If you select this option, microcode patch loading support for AMD
1074 processors will be enabled.
1076 config MICROCODE_OLD_INTERFACE
1078 depends on MICROCODE
1081 tristate "/dev/cpu/*/msr - Model-specific register support"
1082 select XEN_DOMCTL if XEN_PRIVILEGED_GUEST
1084 This device gives privileged processes access to the x86
1085 Model-Specific Registers (MSRs). It is a character device with
1086 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1087 MSR accesses are directed to a specific CPU on multi-processor
1091 tristate "/dev/cpu/*/cpuid - CPU information support"
1093 This device gives processes access to the x86 CPUID instruction to
1094 be executed on a specific processor. It is a character device
1095 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1099 prompt "High Memory Support"
1100 default HIGHMEM64G if X86_NUMAQ || XEN
1106 depends on !X86_NUMAQ
1108 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1109 However, the address space of 32-bit x86 processors is only 4
1110 Gigabytes large. That means that, if you have a large amount of
1111 physical memory, not all of it can be "permanently mapped" by the
1112 kernel. The physical memory that's not permanently mapped is called
1115 If you are compiling a kernel which will never run on a machine with
1116 more than 1 Gigabyte total physical RAM, answer "off" here (default
1117 choice and suitable for most users). This will result in a "3GB/1GB"
1118 split: 3GB are mapped so that each process sees a 3GB virtual memory
1119 space and the remaining part of the 4GB virtual memory space is used
1120 by the kernel to permanently map as much physical memory as
1123 If the machine has between 1 and 4 Gigabytes physical RAM, then
1126 If more than 4 Gigabytes is used then answer "64GB" here. This
1127 selection turns Intel PAE (Physical Address Extension) mode on.
1128 PAE implements 3-level paging on IA32 processors. PAE is fully
1129 supported by Linux, PAE mode is implemented on all recent Intel
1130 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1131 then the kernel will not boot on CPUs that don't support PAE!
1133 The actual amount of total physical memory will either be
1134 auto detected or can be forced by using a kernel command line option
1135 such as "mem=256M". (Try "man bootparam" or see the documentation of
1136 your boot loader (lilo or loadlin) about how to pass options to the
1137 kernel at boot time.)
1139 If unsure, say "off".
1143 depends on !X86_NUMAQ && !XEN
1145 Select this if you have a 32-bit processor and between 1 and 4
1146 gigabytes of physical RAM.
1150 depends on !M386 && !M486
1153 Select this if you have a 32-bit processor and more than 4
1154 gigabytes of physical RAM.
1159 depends on EXPERIMENTAL
1160 prompt "Memory split" if EXPERT
1164 Select the desired split between kernel and user memory.
1166 If the address range available to the kernel is less than the
1167 physical memory installed, the remaining memory will be available
1168 as "high memory". Accessing high memory is a little more costly
1169 than low memory, as it needs to be mapped into the kernel first.
1170 Note that increasing the kernel address space limits the range
1171 available to user programs, making the address space there
1172 tighter. Selecting anything other than the default 3G/1G split
1173 will also likely make your kernel incompatible with binary-only
1176 If you are not absolutely sure what you are doing, leave this
1180 bool "3G/1G user/kernel split"
1181 config VMSPLIT_3G_OPT
1183 bool "3G/1G user/kernel split (for full 1G low memory)"
1185 bool "2G/2G user/kernel split"
1186 config VMSPLIT_2G_OPT
1188 bool "2G/2G user/kernel split (for full 2G low memory)"
1190 bool "1G/3G user/kernel split"
1195 default 0xB0000000 if VMSPLIT_3G_OPT
1196 default 0x80000000 if VMSPLIT_2G
1197 default 0x78000000 if VMSPLIT_2G_OPT
1198 default 0x40000000 if VMSPLIT_1G
1204 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1207 bool "PAE (Physical Address Extension) Support"
1208 depends on X86_32 && !HIGHMEM4G
1210 PAE is required for NX support, and furthermore enables
1211 larger swapspace support for non-overcommit purposes. It
1212 has the cost of more pagetable lookup overhead, and also
1213 consumes more pagetable space per process.
1215 config ARCH_PHYS_ADDR_T_64BIT
1216 def_bool X86_64 || X86_PAE
1218 config ARCH_DMA_ADDR_T_64BIT
1219 def_bool X86_64 || XEN || HIGHMEM64G
1221 config DIRECT_GBPAGES
1222 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1224 depends on X86_64 && !XEN
1226 Allow the kernel linear mapping to use 1GB pages on CPUs that
1227 support it. This can improve the kernel's performance a tiny bit by
1228 reducing TLB pressure. If in doubt, say "Y".
1230 # Common NUMA Features
1232 bool "Numa Memory Allocation and Scheduler Support"
1233 depends on SMP && !XEN
1234 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1235 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1237 Enable NUMA (Non Uniform Memory Access) support.
1239 The kernel will try to allocate memory used by a CPU on the
1240 local memory controller of the CPU and add some more
1241 NUMA awareness to the kernel.
1243 For 64-bit this is recommended if the system is Intel Core i7
1244 (or later), AMD Opteron, or EM64T NUMA.
1246 For 32-bit this is only needed on (rare) 32-bit-only platforms
1247 that support NUMA topologies, such as NUMAQ / Summit, or if you
1248 boot a 32-bit kernel on a 64-bit NUMA platform.
1250 Otherwise, you should say N.
1252 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1253 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1257 prompt "Old style AMD Opteron NUMA detection"
1258 depends on X86_64 && NUMA && PCI
1260 Enable AMD NUMA node topology detection. You should say Y here if
1261 you have a multi processor AMD system. This uses an old method to
1262 read the NUMA configuration directly from the builtin Northbridge
1263 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1264 which also takes priority if both are compiled in.
1266 config X86_64_ACPI_NUMA
1268 prompt "ACPI NUMA detection"
1269 depends on X86_64 && NUMA && ACPI && PCI
1272 Enable ACPI SRAT based node topology detection.
1274 # Some NUMA nodes have memory ranges that span
1275 # other nodes. Even though a pfn is valid and
1276 # between a node's start and end pfns, it may not
1277 # reside on that node. See memmap_init_zone()
1279 config NODES_SPAN_OTHER_NODES
1281 depends on X86_64_ACPI_NUMA
1284 bool "NUMA emulation"
1287 Enable NUMA emulation. A flat machine will be split
1288 into virtual nodes when booted with "numa=fake=N", where N is the
1289 number of nodes. This is only useful for debugging.
1292 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1294 default "10" if MAXSMP
1295 default "6" if X86_64
1296 default "4" if X86_NUMAQ
1298 depends on NEED_MULTIPLE_NODES
1300 Specify the maximum number of NUMA Nodes available on the target
1301 system. Increases memory reserved to accommodate various tables.
1303 config HAVE_ARCH_BOOTMEM
1305 depends on X86_32 && NUMA
1307 config HAVE_ARCH_ALLOC_REMAP
1309 depends on X86_32 && NUMA
1311 config ARCH_HAVE_MEMORY_PRESENT
1313 depends on X86_32 && DISCONTIGMEM
1315 config NEED_NODE_MEMMAP_SIZE
1317 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1319 config ARCH_FLATMEM_ENABLE
1321 depends on X86_32 && !NUMA
1323 config ARCH_DISCONTIGMEM_ENABLE
1325 depends on NUMA && X86_32
1327 config ARCH_DISCONTIGMEM_DEFAULT
1329 depends on NUMA && X86_32
1331 config ARCH_SPARSEMEM_ENABLE
1333 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1335 select SPARSEMEM_STATIC if X86_32
1336 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1338 config ARCH_SPARSEMEM_DEFAULT
1340 depends on X86_64 && !X86_64_XEN
1342 config ARCH_SELECT_MEMORY_MODEL
1344 depends on ARCH_SPARSEMEM_ENABLE
1346 config ARCH_MEMORY_PROBE
1348 depends on MEMORY_HOTPLUG
1350 config ARCH_PROC_KCORE_TEXT
1352 depends on X86_64 && PROC_KCORE
1354 config ILLEGAL_POINTER_VALUE
1357 default 0xdead000000000000 if X86_64
1362 bool "Allocate 3rd-level pagetables from highmem"
1365 The VM uses one page table entry for each page of physical memory.
1366 For systems with a lot of RAM, this can be wasteful of precious
1367 low memory. Setting this option will put user-space page table
1368 entries in high memory.
1370 config X86_CHECK_BIOS_CORRUPTION
1371 bool "Check for low memory corruption"
1374 Periodically check for memory corruption in low memory, which
1375 is suspected to be caused by BIOS. Even when enabled in the
1376 configuration, it is disabled at runtime. Enable it by
1377 setting "memory_corruption_check=1" on the kernel command
1378 line. By default it scans the low 64k of memory every 60
1379 seconds; see the memory_corruption_check_size and
1380 memory_corruption_check_period parameters in
1381 Documentation/kernel-parameters.txt to adjust this.
1383 When enabled with the default parameters, this option has
1384 almost no overhead, as it reserves a relatively small amount
1385 of memory and scans it infrequently. It both detects corruption
1386 and prevents it from affecting the running system.
1388 It is, however, intended as a diagnostic tool; if repeatable
1389 BIOS-originated corruption always affects the same memory,
1390 you can use memmap= to prevent the kernel from using that
1393 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1394 bool "Set the default setting of memory_corruption_check"
1395 depends on X86_CHECK_BIOS_CORRUPTION
1398 Set whether the default state of memory_corruption_check is
1401 config X86_RESERVE_LOW
1402 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1407 Specify the amount of low memory to reserve for the BIOS.
1409 The first page contains BIOS data structures that the kernel
1410 must not use, so that page must always be reserved.
1412 By default we reserve the first 64K of physical RAM, as a
1413 number of BIOSes are known to corrupt that memory range
1414 during events such as suspend/resume or monitor cable
1415 insertion, so it must not be used by the kernel.
1417 You can set this to 4 if you are absolutely sure that you
1418 trust the BIOS to get all its memory reservations and usages
1419 right. If you know your BIOS have problems beyond the
1420 default 64K area, you can set this to 640 to avoid using the
1421 entire low memory range.
1423 If you have doubts about the BIOS (e.g. suspend/resume does
1424 not work or there's kernel crashes after certain hardware
1425 hotplug events) then you might want to enable
1426 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1427 typical corruption patterns.
1429 Leave this to the default value of 64 if you are unsure.
1431 config MATH_EMULATION
1433 prompt "Math emulation" if X86_32
1436 Linux can emulate a math coprocessor (used for floating point
1437 operations) if you don't have one. 486DX and Pentium processors have
1438 a math coprocessor built in, 486SX and 386 do not, unless you added
1439 a 487DX or 387, respectively. (The messages during boot time can
1440 give you some hints here ["man dmesg"].) Everyone needs either a
1441 coprocessor or this emulation.
1443 If you don't have a math coprocessor, you need to say Y here; if you
1444 say Y here even though you have a coprocessor, the coprocessor will
1445 be used nevertheless. (This behavior can be changed with the kernel
1446 command line option "no387", which comes handy if your coprocessor
1447 is broken. Try "man bootparam" or see the documentation of your boot
1448 loader (lilo or loadlin) about how to pass options to the kernel at
1449 boot time.) This means that it is a good idea to say Y here if you
1450 intend to use this kernel on different machines.
1452 More information about the internals of the Linux math coprocessor
1453 emulation can be found in <file:arch/x86/math-emu/README>.
1455 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1456 kernel, it won't hurt.
1460 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1461 depends on !XEN_UNPRIVILEGED_GUEST
1463 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1464 the Memory Type Range Registers (MTRRs) may be used to control
1465 processor access to memory ranges. This is most useful if you have
1466 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1467 allows bus write transfers to be combined into a larger transfer
1468 before bursting over the PCI/AGP bus. This can increase performance
1469 of image write operations 2.5 times or more. Saying Y here creates a
1470 /proc/mtrr file which may be used to manipulate your processor's
1471 MTRRs. Typically the X server should use this.
1473 This code has a reasonably generic interface so that similar
1474 control registers on other processors can be easily supported
1477 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1478 Registers (ARRs) which provide a similar functionality to MTRRs. For
1479 these, the ARRs are used to emulate the MTRRs.
1480 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1481 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1482 write-combining. All of these processors are supported by this code
1483 and it makes sense to say Y here if you have one of them.
1485 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1486 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1487 can lead to all sorts of problems, so it's good to say Y here.
1489 You can safely say Y even if your machine doesn't have MTRRs, you'll
1490 just add about 9 KB to your kernel.
1492 See <file:Documentation/x86/mtrr.txt> for more information.
1494 config MTRR_SANITIZER
1496 prompt "MTRR cleanup support"
1497 depends on MTRR && !XEN
1499 Convert MTRR layout from continuous to discrete, so X drivers can
1500 add writeback entries.
1502 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1503 The largest mtrr entry size for a continuous block can be set with
1508 config MTRR_SANITIZER_ENABLE_DEFAULT
1509 int "MTRR cleanup enable value (0-1)"
1512 depends on MTRR_SANITIZER
1514 Enable mtrr cleanup default value
1516 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1517 int "MTRR cleanup spare reg num (0-7)"
1520 depends on MTRR_SANITIZER
1522 mtrr cleanup spare entries default, it can be changed via
1523 mtrr_spare_reg_nr=N on the kernel command line.
1527 prompt "x86 PAT support" if EXPERT || XEN_UNPRIVILEGED_GUEST
1528 depends on MTRR || (XEN_UNPRIVILEGED_GUEST && XEN_PCIDEV_FRONTEND)
1530 Use PAT attributes to setup page level cache control.
1532 PATs are the modern equivalents of MTRRs and are much more
1533 flexible than MTRRs.
1535 Say N here if you see bootup problems (boot crash, boot hang,
1536 spontaneous reboots) or a non-working video driver.
1540 config ARCH_USES_PG_UNCACHED
1546 prompt "x86 architectural random number generator" if EXPERT
1548 Enable the x86 architectural RDRAND instruction
1549 (Intel Bull Mountain technology) to generate random numbers.
1550 If supported, this is a high bandwidth, cryptographically
1551 secure hardware random number generator.
1554 bool "EFI runtime service support"
1555 depends on ACPI && !XEN_UNPRIVILEGED_GUEST
1557 This enables the kernel to use EFI runtime services that are
1558 available (such as the EFI variable services).
1560 This option is only useful on systems that have EFI firmware.
1561 In addition, you should use the latest ELILO loader available
1562 at <http://elilo.sourceforge.net> in order to take advantage
1563 of EFI runtime services. However, even with this option, the
1564 resultant kernel should continue to boot on existing non-EFI
1568 bool "EFI stub support"
1569 depends on EFI && !XEN
1571 This kernel feature allows a bzImage to be loaded directly
1572 by EFI firmware without the use of a bootloader.
1576 prompt "Enable seccomp to safely compute untrusted bytecode"
1578 This kernel feature is useful for number crunching applications
1579 that may need to compute untrusted bytecode during their
1580 execution. By using pipes or other transports made available to
1581 the process as file descriptors supporting the read/write
1582 syscalls, it's possible to isolate those applications in
1583 their own address space using seccomp. Once seccomp is
1584 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1585 and the task is only allowed to execute a few safe syscalls
1586 defined by each seccomp mode.
1588 If unsure, say Y. Only embedded should say N here.
1590 config CC_STACKPROTECTOR
1591 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1593 This option turns on the -fstack-protector GCC feature. This
1594 feature puts, at the beginning of functions, a canary value on
1595 the stack just before the return address, and validates
1596 the value just before actually returning. Stack based buffer
1597 overflows (that need to overwrite this return address) now also
1598 overwrite the canary, which gets detected and the attack is then
1599 neutralized via a kernel panic.
1601 This feature requires gcc version 4.2 or above, or a distribution
1602 gcc with the feature backported. Older versions are automatically
1603 detected and for those versions, this configuration option is
1604 ignored. (and a warning is printed during bootup)
1606 source kernel/Kconfig.hz
1609 bool "kexec system call"
1610 depends on !XEN_UNPRIVILEGED_GUEST
1612 kexec is a system call that implements the ability to shutdown your
1613 current kernel, and to start another kernel. It is like a reboot
1614 but it is independent of the system firmware. And like a reboot
1615 you can start any kernel with it, not just Linux.
1617 The name comes from the similarity to the exec system call.
1619 It is an ongoing process to be certain the hardware in a machine
1620 is properly shutdown, so do not be surprised if this code does not
1621 initially work for you. It may help to enable device hotplugging
1622 support. As of this writing the exact hardware interface is
1623 strongly in flux, so no good recommendation can be made.
1626 bool "kernel crash dumps"
1627 depends on X86_64 || (X86_32 && HIGHMEM)
1630 Generate crash dump after being started by kexec.
1631 This should be normally only set in special crash dump kernels
1632 which are loaded in the main kernel with kexec-tools into
1633 a specially reserved region and then later executed after
1634 a crash by kdump/kexec. The crash dump kernel must be compiled
1635 to a memory address not used by the main kernel or BIOS using
1636 PHYSICAL_START, or it must be built as a relocatable image
1637 (CONFIG_RELOCATABLE=y).
1638 For more details see Documentation/kdump/kdump.txt
1641 bool "kexec jump (EXPERIMENTAL)"
1642 depends on EXPERIMENTAL
1643 depends on KEXEC && HIBERNATION
1645 Jump between original kernel and kexeced kernel and invoke
1646 code in physical address mode via KEXEC
1648 config PHYSICAL_START
1649 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP || XEN)
1650 default 0x100000 if XEN
1653 This gives the physical address where the kernel is loaded.
1655 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1656 bzImage will decompress itself to above physical address and
1657 run from there. Otherwise, bzImage will run from the address where
1658 it has been loaded by the boot loader and will ignore above physical
1661 In normal kdump cases one does not have to set/change this option
1662 as now bzImage can be compiled as a completely relocatable image
1663 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1664 address. This option is mainly useful for the folks who don't want
1665 to use a bzImage for capturing the crash dump and want to use a
1666 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1667 to be specifically compiled to run from a specific memory area
1668 (normally a reserved region) and this option comes handy.
1670 So if you are using bzImage for capturing the crash dump,
1671 leave the value here unchanged to 0x1000000 and set
1672 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1673 for capturing the crash dump change this value to start of
1674 the reserved region. In other words, it can be set based on
1675 the "X" value as specified in the "crashkernel=YM@XM"
1676 command line boot parameter passed to the panic-ed
1677 kernel. Please take a look at Documentation/kdump/kdump.txt
1678 for more details about crash dumps.
1680 Usage of bzImage for capturing the crash dump is recommended as
1681 one does not have to build two kernels. Same kernel can be used
1682 as production kernel and capture kernel. Above option should have
1683 gone away after relocatable bzImage support is introduced. But it
1684 is present because there are users out there who continue to use
1685 vmlinux for dump capture. This option should go away down the
1688 Don't change this unless you know what you are doing.
1691 bool "Build a relocatable kernel"
1695 This builds a kernel image that retains relocation information
1696 so it can be loaded someplace besides the default 1MB.
1697 The relocations tend to make the kernel binary about 10% larger,
1698 but are discarded at runtime.
1700 One use is for the kexec on panic case where the recovery kernel
1701 must live at a different physical address than the primary
1704 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1705 it has been loaded at and the compile time physical address
1706 (CONFIG_PHYSICAL_START) is ignored.
1708 # Relocation on x86-32 needs some additional build support
1709 config X86_NEED_RELOCS
1711 depends on X86_32 && RELOCATABLE
1713 config PHYSICAL_ALIGN
1714 hex "Alignment value to which kernel should be aligned" if X86_32 && !XEN
1715 default 0x2000 if XEN
1717 range 0x2000 0x1000000
1719 This value puts the alignment restrictions on physical address
1720 where kernel is loaded and run from. Kernel is compiled for an
1721 address which meets above alignment restriction.
1723 If bootloader loads the kernel at a non-aligned address and
1724 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1725 address aligned to above value and run from there.
1727 If bootloader loads the kernel at a non-aligned address and
1728 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1729 load address and decompress itself to the address it has been
1730 compiled for and run from there. The address for which kernel is
1731 compiled already meets above alignment restrictions. Hence the
1732 end result is that kernel runs from a physical address meeting
1733 above alignment restrictions.
1735 Don't change this unless you know what you are doing.
1738 bool "Support for hot-pluggable CPUs"
1739 depends on SMP && HOTPLUG
1741 Say Y here to allow turning CPUs off and on. CPUs can be
1742 controlled through /sys/devices/system/cpu.
1743 ( Note: power management support will enable this option
1744 automatically on SMP systems. )
1745 Say N if you want to disable CPU hotplug.
1749 prompt "Compat VDSO support"
1750 depends on X86_32 || IA32_EMULATION
1752 Map the 32-bit VDSO to the predictable old-style address too.
1754 Say N here if you are running a sufficiently recent glibc
1755 version (2.3.3 or later), to remove the high-mapped
1756 VDSO mapping and to exclusively use the randomized VDSO.
1761 bool "Built-in kernel command line"
1763 Allow for specifying boot arguments to the kernel at
1764 build time. On some systems (e.g. embedded ones), it is
1765 necessary or convenient to provide some or all of the
1766 kernel boot arguments with the kernel itself (that is,
1767 to not rely on the boot loader to provide them.)
1769 To compile command line arguments into the kernel,
1770 set this option to 'Y', then fill in the
1771 the boot arguments in CONFIG_CMDLINE.
1773 Systems with fully functional boot loaders (i.e. non-embedded)
1774 should leave this option set to 'N'.
1777 string "Built-in kernel command string"
1778 depends on CMDLINE_BOOL
1781 Enter arguments here that should be compiled into the kernel
1782 image and used at boot time. If the boot loader provides a
1783 command line at boot time, it is appended to this string to
1784 form the full kernel command line, when the system boots.
1786 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1787 change this behavior.
1789 In most cases, the command line (whether built-in or provided
1790 by the boot loader) should specify the device for the root
1793 config CMDLINE_OVERRIDE
1794 bool "Built-in command line overrides boot loader arguments"
1795 depends on CMDLINE_BOOL
1797 Set this option to 'Y' to have the kernel ignore the boot loader
1798 command line, and use ONLY the built-in command line.
1800 This is used to work around broken boot loaders. This should
1801 be set to 'N' under normal conditions.
1805 config ARCH_ENABLE_MEMORY_HOTPLUG
1807 depends on X86_64 || (X86_32 && HIGHMEM)
1810 config ARCH_ENABLE_MEMORY_HOTREMOVE
1812 depends on MEMORY_HOTPLUG
1814 config USE_PERCPU_NUMA_NODE_ID
1818 menu "Power management and ACPI options"
1820 config ARCH_HIBERNATION_HEADER
1822 depends on X86_64 && HIBERNATION
1824 source "kernel/power/Kconfig"
1826 if !XEN_UNPRIVILEGED_GUEST
1828 source "drivers/acpi/Kconfig"
1830 source "drivers/sfi/Kconfig"
1837 tristate "APM (Advanced Power Management) BIOS support"
1838 depends on X86_32 && PM_SLEEP && !XEN
1840 APM is a BIOS specification for saving power using several different
1841 techniques. This is mostly useful for battery powered laptops with
1842 APM compliant BIOSes. If you say Y here, the system time will be
1843 reset after a RESUME operation, the /proc/apm device will provide
1844 battery status information, and user-space programs will receive
1845 notification of APM "events" (e.g. battery status change).
1847 If you select "Y" here, you can disable actual use of the APM
1848 BIOS by passing the "apm=off" option to the kernel at boot time.
1850 Note that the APM support is almost completely disabled for
1851 machines with more than one CPU.
1853 In order to use APM, you will need supporting software. For location
1854 and more information, read <file:Documentation/power/apm-acpi.txt>
1855 and the Battery Powered Linux mini-HOWTO, available from
1856 <http://www.tldp.org/docs.html#howto>.
1858 This driver does not spin down disk drives (see the hdparm(8)
1859 manpage ("man 8 hdparm") for that), and it doesn't turn off
1860 VESA-compliant "green" monitors.
1862 This driver does not support the TI 4000M TravelMate and the ACER
1863 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1864 desktop machines also don't have compliant BIOSes, and this driver
1865 may cause those machines to panic during the boot phase.
1867 Generally, if you don't have a battery in your machine, there isn't
1868 much point in using this driver and you should say N. If you get
1869 random kernel OOPSes or reboots that don't seem to be related to
1870 anything, try disabling/enabling this option (or disabling/enabling
1873 Some other things you should try when experiencing seemingly random,
1876 1) make sure that you have enough swap space and that it is
1878 2) pass the "no-hlt" option to the kernel
1879 3) switch on floating point emulation in the kernel and pass
1880 the "no387" option to the kernel
1881 4) pass the "floppy=nodma" option to the kernel
1882 5) pass the "mem=4M" option to the kernel (thereby disabling
1883 all but the first 4 MB of RAM)
1884 6) make sure that the CPU is not over clocked.
1885 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1886 8) disable the cache from your BIOS settings
1887 9) install a fan for the video card or exchange video RAM
1888 10) install a better fan for the CPU
1889 11) exchange RAM chips
1890 12) exchange the motherboard.
1892 To compile this driver as a module, choose M here: the
1893 module will be called apm.
1897 config APM_IGNORE_USER_SUSPEND
1898 bool "Ignore USER SUSPEND"
1900 This option will ignore USER SUSPEND requests. On machines with a
1901 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1902 series notebooks, it is necessary to say Y because of a BIOS bug.
1904 config APM_DO_ENABLE
1905 bool "Enable PM at boot time"
1907 Enable APM features at boot time. From page 36 of the APM BIOS
1908 specification: "When disabled, the APM BIOS does not automatically
1909 power manage devices, enter the Standby State, enter the Suspend
1910 State, or take power saving steps in response to CPU Idle calls."
1911 This driver will make CPU Idle calls when Linux is idle (unless this
1912 feature is turned off -- see "Do CPU IDLE calls", below). This
1913 should always save battery power, but more complicated APM features
1914 will be dependent on your BIOS implementation. You may need to turn
1915 this option off if your computer hangs at boot time when using APM
1916 support, or if it beeps continuously instead of suspending. Turn
1917 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1918 T400CDT. This is off by default since most machines do fine without
1922 bool "Make CPU Idle calls when idle"
1924 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1925 On some machines, this can activate improved power savings, such as
1926 a slowed CPU clock rate, when the machine is idle. These idle calls
1927 are made after the idle loop has run for some length of time (e.g.,
1928 333 mS). On some machines, this will cause a hang at boot time or
1929 whenever the CPU becomes idle. (On machines with more than one CPU,
1930 this option does nothing.)
1932 config APM_DISPLAY_BLANK
1933 bool "Enable console blanking using APM"
1935 Enable console blanking using the APM. Some laptops can use this to
1936 turn off the LCD backlight when the screen blanker of the Linux
1937 virtual console blanks the screen. Note that this is only used by
1938 the virtual console screen blanker, and won't turn off the backlight
1939 when using the X Window system. This also doesn't have anything to
1940 do with your VESA-compliant power-saving monitor. Further, this
1941 option doesn't work for all laptops -- it might not turn off your
1942 backlight at all, or it might print a lot of errors to the console,
1943 especially if you are using gpm.
1945 config APM_ALLOW_INTS
1946 bool "Allow interrupts during APM BIOS calls"
1948 Normally we disable external interrupts while we are making calls to
1949 the APM BIOS as a measure to lessen the effects of a badly behaving
1950 BIOS implementation. The BIOS should reenable interrupts if it
1951 needs to. Unfortunately, some BIOSes do not -- especially those in
1952 many of the newer IBM Thinkpads. If you experience hangs when you
1953 suspend, try setting this to Y. Otherwise, say N.
1957 source "drivers/cpufreq/Kconfig"
1959 source "drivers/cpuidle/Kconfig"
1961 source "drivers/idle/Kconfig"
1963 endif # !XEN_UNPRIVILEGED_GUEST
1968 menu "Bus options (PCI etc.)"
1973 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1974 select ARCH_SUPPORTS_MSI if (XEN_UNPRIVILEGED_GUEST && XEN_PCIDEV_FRONTEND)
1976 Find out whether you have a PCI motherboard. PCI is the name of a
1977 bus system, i.e. the way the CPU talks to the other stuff inside
1978 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1979 VESA. If you have PCI, say Y, otherwise N.
1982 prompt "PCI access mode"
1983 depends on X86_32 && PCI
1986 On PCI systems, the BIOS can be used to detect the PCI devices and
1987 determine their configuration. However, some old PCI motherboards
1988 have BIOS bugs and may crash if this is done. Also, some embedded
1989 PCI-based systems don't have any BIOS at all. Linux can also try to
1990 detect the PCI hardware directly without using the BIOS.
1992 With this option, you can specify how Linux should detect the
1993 PCI devices. If you choose "BIOS", the BIOS will be used,
1994 if you choose "Direct", the BIOS won't be used, and if you
1995 choose "MMConfig", then PCI Express MMCONFIG will be used.
1996 If you choose "Any", the kernel will try MMCONFIG, then the
1997 direct access method and falls back to the BIOS if that doesn't
1998 work. If unsure, go with the default, which is "Any".
2004 config PCI_GOMMCONFIG
2006 depends on !XEN_UNPRIVILEGED_GUEST
2010 depends on !XEN_UNPRIVILEGED_GUEST
2014 depends on OLPC && !XEN_UNPRIVILEGED_GUEST
2017 bool "Xen PCI Frontend"
2020 The PCI device frontend driver allows the kernel to import arbitrary
2021 PCI devices from a PCI backend to support PCI driver domains.
2025 depends on !XEN_UNPRIVILEGED_GUEST
2031 depends on X86_32 && PCI && !XEN && (PCI_GOBIOS || PCI_GOANY)
2033 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2036 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2040 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2044 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2048 depends on PCI && PARAVIRT_XEN
2056 bool "Support mmconfig PCI config space access"
2057 depends on X86_64 && PCI && ACPI
2059 config PCI_CNB20LE_QUIRK
2060 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2062 depends on PCI && EXPERIMENTAL
2064 Read the PCI windows out of the CNB20LE host bridge. This allows
2065 PCI hotplug to work on systems with the CNB20LE chipset which do
2068 There's no public spec for this chipset, and this functionality
2069 is known to be incomplete.
2071 You should say N unless you know you need this.
2073 source "drivers/pci/pcie/Kconfig"
2075 source "drivers/pci/Kconfig"
2077 # x86_64 have no ISA slots, but can have ISA-style DMA.
2079 bool "ISA-style DMA support" if ((X86_64 || XEN) && EXPERT) || XEN_UNPRIVILEGED_GUEST
2082 Enables ISA-style DMA support for devices requiring such controllers.
2091 Find out whether you have ISA slots on your motherboard. ISA is the
2092 name of a bus system, i.e. the way the CPU talks to the other stuff
2093 inside your box. Other bus systems are PCI, EISA, MicroChannel
2094 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2095 newer boards don't support it. If you have ISA, say Y, otherwise N.
2101 The Extended Industry Standard Architecture (EISA) bus was
2102 developed as an open alternative to the IBM MicroChannel bus.
2104 The EISA bus provided some of the features of the IBM MicroChannel
2105 bus while maintaining backward compatibility with cards made for
2106 the older ISA bus. The EISA bus saw limited use between 1988 and
2107 1995 when it was made obsolete by the PCI bus.
2109 Say Y here if you are building a kernel for an EISA-based machine.
2113 source "drivers/eisa/Kconfig"
2119 MicroChannel Architecture is found in some IBM PS/2 machines and
2120 laptops. It is a bus system similar to PCI or ISA. See
2121 <file:Documentation/mca.txt> (and especially the web page given
2122 there) before attempting to build an MCA bus kernel.
2124 source "drivers/mca/Kconfig"
2127 tristate "NatSemi SCx200 support"
2129 This provides basic support for National Semiconductor's
2130 (now AMD's) Geode processors. The driver probes for the
2131 PCI-IDs of several on-chip devices, so its a good dependency
2132 for other scx200_* drivers.
2134 If compiled as a module, the driver is named scx200.
2136 config SCx200HR_TIMER
2137 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2141 This driver provides a clocksource built upon the on-chip
2142 27MHz high-resolution timer. Its also a workaround for
2143 NSC Geode SC-1100's buggy TSC, which loses time when the
2144 processor goes idle (as is done by the scheduler). The
2145 other workaround is idle=poll boot option.
2148 bool "One Laptop Per Child support"
2149 depends on !X86_PAE && !XEN
2154 Add support for detecting the unique features of the OLPC
2158 bool "OLPC XO-1 Power Management"
2159 depends on OLPC && MFD_CS5535 && PM_SLEEP
2162 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2165 bool "OLPC XO-1 Real Time Clock"
2166 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2168 Add support for the XO-1 real time clock, which can be used as a
2169 programmable wakeup source.
2172 bool "OLPC XO-1 SCI extras"
2173 depends on OLPC && OLPC_XO1_PM
2178 Add support for SCI-based features of the OLPC XO-1 laptop:
2179 - EC-driven system wakeups
2183 - AC adapter status updates
2184 - Battery status updates
2186 config OLPC_XO15_SCI
2187 bool "OLPC XO-1.5 SCI extras"
2188 depends on OLPC && ACPI
2191 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2192 - EC-driven system wakeups
2193 - AC adapter status updates
2194 - Battery status updates
2197 bool "PCEngines ALIX System Support (LED setup)"
2200 This option enables system support for the PCEngines ALIX.
2201 At present this just sets up LEDs for GPIO control on
2202 ALIX2/3/6 boards. However, other system specific setup should
2205 Note: You must still enable the drivers for GPIO and LED support
2206 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2208 Note: You have to set alix.force=1 for boards with Award BIOS.
2214 depends on CPU_SUP_AMD && PCI && !XEN_UNPRIVILEGED_GUEST
2216 source "drivers/pcmcia/Kconfig"
2218 source "drivers/pci/hotplug/Kconfig"
2221 bool "RapidIO support"
2225 If you say Y here, the kernel will include drivers and
2226 infrastructure code to support RapidIO interconnect devices.
2228 source "drivers/rapidio/Kconfig"
2233 menu "Executable file formats / Emulations"
2235 source "fs/Kconfig.binfmt"
2237 config IA32_EMULATION
2238 bool "IA32 Emulation"
2240 select COMPAT_BINFMT_ELF
2242 Include code to run 32-bit programs under a 64-bit kernel. You should
2243 likely turn this on, unless you're 100% sure that you don't have any
2244 32-bit programs left.
2247 tristate "IA32 a.out support"
2248 depends on IA32_EMULATION
2250 Support old a.out binaries in the 32bit emulation.
2254 depends on IA32_EMULATION
2256 config COMPAT_FOR_U64_ALIGNMENT
2260 config SYSVIPC_COMPAT
2262 depends on COMPAT && SYSVIPC
2266 depends on COMPAT && KEYS
2272 config HAVE_ATOMIC_IOMAP
2276 config HAVE_TEXT_POKE_SMP
2278 select STOP_MACHINE if SMP
2280 source "net/Kconfig"
2282 source "drivers/Kconfig"
2284 if !XEN_UNPRIVILEGED_GUEST
2285 source "drivers/firmware/Kconfig"
2290 source "arch/x86/Kconfig.debug"
2292 source "security/Kconfig"
2294 source "crypto/Kconfig"
2296 source "arch/x86/kvm/Kconfig"
2298 source "lib/Kconfig"
projects / linux-flexiantxendom0-3.2.10.git / blob