3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
19 select HAVE_AOUT if X86_32
20 select HAVE_UNSTABLE_SCHED_CLOCK
23 select HAVE_PCSPKR_PLATFORM
24 select HAVE_PERF_EVENTS
26 select HAVE_IOREMAP_PROT
29 select 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
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
55 select HAVE_KERNEL_LZMA
57 select HAVE_KERNEL_LZO
58 select HAVE_HW_BREAKPOINT
59 select HAVE_MIXED_BREAKPOINTS_REGS
61 select HAVE_PERF_EVENTS_NMI
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)
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
105 config GENERIC_CLOCKEVENTS
108 config ARCH_CLOCKSOURCE_DATA
112 config GENERIC_CLOCKEVENTS_BROADCAST
114 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
116 config LOCKDEP_SUPPORT
119 config STACKTRACE_SUPPORT
122 config HAVE_LATENCYTOP_SUPPORT
131 config NEED_DMA_MAP_STATE
132 def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG)
134 config NEED_SG_DMA_LENGTH
137 config GENERIC_ISA_DMA
143 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
145 config GENERIC_BUG_RELATIVE_POINTERS
148 config GENERIC_HWEIGHT
154 config ARCH_MAY_HAVE_PC_FDC
157 config RWSEM_GENERIC_SPINLOCK
160 config RWSEM_XCHGADD_ALGORITHM
163 config ARCH_HAS_CPU_IDLE_WAIT
166 config GENERIC_CALIBRATE_DELAY
169 config GENERIC_TIME_VSYSCALL
173 config ARCH_HAS_CPU_RELAX
176 config ARCH_HAS_DEFAULT_IDLE
179 config ARCH_HAS_CACHE_LINE_SIZE
182 config HAVE_SETUP_PER_CPU_AREA
185 config NEED_PER_CPU_EMBED_FIRST_CHUNK
188 config NEED_PER_CPU_PAGE_FIRST_CHUNK
191 config ARCH_HIBERNATION_POSSIBLE
194 config ARCH_SUSPEND_POSSIBLE
205 config ARCH_SUPPORTS_OPTIMIZED_INLINING
208 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
211 config HAVE_INTEL_TXT
213 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
217 depends on X86_32 && SMP
221 depends on X86_64 && SMP
227 config X86_32_LAZY_GS
229 depends on X86_32 && !CC_STACKPROTECTOR
231 config ARCH_HWEIGHT_CFLAGS
233 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
234 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
239 config ARCH_CPU_PROBE_RELEASE
241 depends on HOTPLUG_CPU
243 source "init/Kconfig"
244 source "kernel/Kconfig.freezer"
246 menu "Processor type and features"
249 bool "DMA memory allocation support" if EXPERT
252 DMA memory allocation support allows devices with less than 32-bit
253 addressing to allocate within the first 16MB of address space.
254 Disable if no such devices will be used.
258 source "kernel/time/Kconfig"
261 bool "Symmetric multi-processing support"
263 This enables support for systems with more than one CPU. If you have
264 a system with only one CPU, like most personal computers, say N. If
265 you have a system with more than one CPU, say Y.
267 If you say N here, the kernel will run on single and multiprocessor
268 machines, but will use only one CPU of a multiprocessor machine. If
269 you say Y here, the kernel will run on many, but not all,
270 singleprocessor machines. On a singleprocessor machine, the kernel
271 will run faster if you say N here.
273 Note that if you say Y here and choose architecture "586" or
274 "Pentium" under "Processor family", the kernel will not work on 486
275 architectures. Similarly, multiprocessor kernels for the "PPro"
276 architecture may not work on all Pentium based boards.
278 People using multiprocessor machines who say Y here should also say
279 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
280 Management" code will be disabled if you say Y here.
282 See also <file:Documentation/x86/i386/IO-APIC.txt>,
283 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
284 <http://www.tldp.org/docs.html#howto>.
286 If you don't know what to do here, say N.
289 bool "Support x2apic"
290 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
292 This enables x2apic support on CPUs that have this feature.
294 This allows 32-bit apic IDs (so it can support very large systems),
295 and accesses the local apic via MSRs not via mmio.
297 If you don't know what to do here, say N.
300 bool "Enable MPS table" if ACPI
302 depends on X86_LOCAL_APIC
304 For old smp systems that do not have proper acpi support. Newer systems
305 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
308 bool "Support for big SMP systems with more than 8 CPUs"
309 depends on X86_32 && SMP
311 This option is needed for the systems that have more than 8 CPUs
314 config X86_EXTENDED_PLATFORM
315 bool "Support for extended (non-PC) x86 platforms"
318 If you disable this option then the kernel will only support
319 standard PC platforms. (which covers the vast majority of
322 If you enable this option then you'll be able to select support
323 for the following (non-PC) 32 bit x86 platforms:
327 SGI 320/540 (Visual Workstation)
328 Summit/EXA (IBM x440)
329 Unisys ES7000 IA32 series
330 Moorestown MID devices
332 If you have one of these systems, or if you want to build a
333 generic distribution kernel, say Y here - otherwise say N.
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) 64 bit x86 platforms:
351 If you have one of these systems, or if you want to build a
352 generic distribution kernel, say Y here - otherwise say N.
354 # This is an alphabetically sorted list of 64 bit extended platforms
355 # Please maintain the alphabetic order if and when there are additions
357 bool "Numascale NumaChip"
359 depends on X86_EXTENDED_PLATFORM
362 depends on X86_X2APIC
364 Adds support for Numascale NumaChip large-SMP systems. Needed to
365 enable more than ~168 cores.
366 If you don't have one of these, you should say N here.
370 select PARAVIRT_GUEST
372 depends on X86_64 && PCI
373 depends on X86_EXTENDED_PLATFORM
375 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
376 supposed to run on these EM64T-based machines. Only choose this option
377 if you have one of these machines.
380 bool "SGI Ultraviolet"
382 depends on X86_EXTENDED_PLATFORM
384 depends on X86_X2APIC
386 This option is needed in order to support SGI Ultraviolet systems.
387 If you don't have one of these, you should say N here.
389 # Following is an alphabetically sorted list of 32 bit extended platforms
390 # Please maintain the alphabetic order if and when there are additions
393 bool "CE4100 TV platform"
395 depends on PCI_GODIRECT
397 depends on X86_EXTENDED_PLATFORM
398 select X86_REBOOTFIXUPS
400 select OF_EARLY_FLATTREE
402 Select for the Intel CE media processor (CE4100) SOC.
403 This option compiles in support for the CE4100 SOC for settop
404 boxes and media devices.
406 config X86_WANT_INTEL_MID
407 bool "Intel MID platform support"
409 depends on X86_EXTENDED_PLATFORM
411 Select to build a kernel capable of supporting Intel MID platform
412 systems which do not have the PCI legacy interfaces (Moorestown,
413 Medfield). If you are building for a PC class system say N here.
415 if X86_WANT_INTEL_MID
421 bool "Moorestown MID platform"
424 depends on X86_IO_APIC
432 select X86_PLATFORM_DEVICES
434 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
435 Internet Device(MID) platform. Moorestown consists of two chips:
436 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
437 Unlike standard x86 PCs, Moorestown does not have many legacy devices
438 nor standard legacy replacement devices/features. e.g. Moorestown does
439 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
442 bool "Medfield MID platform"
445 depends on X86_IO_APIC
453 select X86_PLATFORM_DEVICES
455 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
456 Internet Device(MID) platform.
457 Unlike standard x86 PCs, Medfield does not have many legacy devices
458 nor standard legacy replacement devices/features. e.g. Medfield does
459 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
464 bool "RDC R-321x SoC"
466 depends on X86_EXTENDED_PLATFORM
468 select X86_REBOOTFIXUPS
470 This option is needed for RDC R-321x system-on-chip, also known
472 If you don't have one of these chips, you should say N here.
474 config X86_32_NON_STANDARD
475 bool "Support non-standard 32-bit SMP architectures"
476 depends on X86_32 && SMP
477 depends on X86_EXTENDED_PLATFORM
479 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
480 subarchitectures. It is intended for a generic binary kernel.
481 if you select them all, kernel will probe it one by one. and will
484 # Alphabetically sorted list of Non standard 32 bit platforms
487 bool "NUMAQ (IBM/Sequent)"
488 depends on X86_32_NON_STANDARD
493 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
494 NUMA multiquad box. This changes the way that processors are
495 bootstrapped, and uses Clustered Logical APIC addressing mode instead
496 of Flat Logical. You will need a new lynxer.elf file to flash your
497 firmware with - send email to <Martin.Bligh@us.ibm.com>.
499 config X86_SUPPORTS_MEMORY_FAILURE
501 # MCE code calls memory_failure():
503 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
504 depends on !X86_NUMAQ
505 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
506 depends on X86_64 || !SPARSEMEM
507 select ARCH_SUPPORTS_MEMORY_FAILURE
510 bool "SGI 320/540 (Visual Workstation)"
511 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
512 depends on X86_32_NON_STANDARD
514 The SGI Visual Workstation series is an IA32-based workstation
515 based on SGI systems chips with some legacy PC hardware attached.
517 Say Y here to create a kernel to run on the SGI 320 or 540.
519 A kernel compiled for the Visual Workstation will run on general
520 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
523 bool "Summit/EXA (IBM x440)"
524 depends on X86_32_NON_STANDARD
526 This option is needed for IBM systems that use the Summit/EXA chipset.
527 In particular, it is needed for the x440.
530 bool "Unisys ES7000 IA32 series"
531 depends on X86_32_NON_STANDARD && X86_BIGSMP
533 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
534 supposed to run on an IA32-based Unisys ES7000 system.
537 tristate "Eurobraille/Iris poweroff module"
540 The Iris machines from EuroBraille do not have APM or ACPI support
541 to shut themselves down properly. A special I/O sequence is
542 needed to do so, which is what this module does at
545 This is only for Iris machines from EuroBraille.
549 config SCHED_OMIT_FRAME_POINTER
551 prompt "Single-depth WCHAN output"
554 Calculate simpler /proc/<PID>/wchan values. If this option
555 is disabled then wchan values will recurse back to the
556 caller function. This provides more accurate wchan values,
557 at the expense of slightly more scheduling overhead.
559 If in doubt, say "Y".
561 menuconfig PARAVIRT_GUEST
562 bool "Paravirtualized guest support"
564 Say Y here to get to see options related to running Linux under
565 various hypervisors. This option alone does not add any kernel code.
567 If you say N, all options in this submenu will be skipped and disabled.
571 config PARAVIRT_TIME_ACCOUNTING
572 bool "Paravirtual steal time accounting"
576 Select this option to enable fine granularity task steal time
577 accounting. Time spent executing other tasks in parallel with
578 the current vCPU is discounted from the vCPU power. To account for
579 that, there can be a small performance impact.
581 If in doubt, say N here.
583 source "arch/x86/xen/Kconfig"
586 bool "KVM paravirtualized clock"
588 select PARAVIRT_CLOCK
590 Turning on this option will allow you to run a paravirtualized clock
591 when running over the KVM hypervisor. Instead of relying on a PIT
592 (or probably other) emulation by the underlying device model, the host
593 provides the guest with timing infrastructure such as time of day, and
597 bool "KVM Guest support"
600 This option enables various optimizations for running under the KVM
603 source "arch/x86/lguest/Kconfig"
606 bool "Enable paravirtualization code"
608 This changes the kernel so it can modify itself when it is run
609 under a hypervisor, potentially improving performance significantly
610 over full virtualization. However, when run without a hypervisor
611 the kernel is theoretically slower and slightly larger.
613 config PARAVIRT_SPINLOCKS
614 bool "Paravirtualization layer for spinlocks"
615 depends on PARAVIRT && SMP && EXPERIMENTAL
617 Paravirtualized spinlocks allow a pvops backend to replace the
618 spinlock implementation with something virtualization-friendly
619 (for example, block the virtual CPU rather than spinning).
621 Unfortunately the downside is an up to 5% performance hit on
622 native kernels, with various workloads.
624 If you are unsure how to answer this question, answer N.
626 config PARAVIRT_CLOCK
631 config PARAVIRT_DEBUG
632 bool "paravirt-ops debugging"
633 depends on PARAVIRT && DEBUG_KERNEL
635 Enable to debug paravirt_ops internals. Specifically, BUG if
636 a paravirt_op is missing when it is called.
644 This option adds a kernel parameter 'memtest', which allows memtest
646 memtest=0, mean disabled; -- default
647 memtest=1, mean do 1 test pattern;
649 memtest=4, mean do 4 test patterns.
650 If you are unsure how to answer this question, answer N.
652 config X86_SUMMIT_NUMA
654 depends on X86_32 && NUMA && X86_32_NON_STANDARD
656 config X86_CYCLONE_TIMER
658 depends on X86_SUMMIT
660 source "arch/x86/Kconfig.cpu"
664 prompt "HPET Timer Support" if X86_32
666 Use the IA-PC HPET (High Precision Event Timer) to manage
667 time in preference to the PIT and RTC, if a HPET is
669 HPET is the next generation timer replacing legacy 8254s.
670 The HPET provides a stable time base on SMP
671 systems, unlike the TSC, but it is more expensive to access,
672 as it is off-chip. You can find the HPET spec at
673 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
675 You can safely choose Y here. However, HPET will only be
676 activated if the platform and the BIOS support this feature.
677 Otherwise the 8254 will be used for timing services.
679 Choose N to continue using the legacy 8254 timer.
681 config HPET_EMULATE_RTC
683 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
686 def_bool y if X86_INTEL_MID
687 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
689 depends on X86_INTEL_MID && SFI
691 APB timer is the replacement for 8254, HPET on X86 MID platforms.
692 The APBT provides a stable time base on SMP
693 systems, unlike the TSC, but it is more expensive to access,
694 as it is off-chip. APB timers are always running regardless of CPU
695 C states, they are used as per CPU clockevent device when possible.
697 # Mark as expert because too many people got it wrong.
698 # The code disables itself when not needed.
701 bool "Enable DMI scanning" if EXPERT
703 Enabled scanning of DMI to identify machine quirks. Say Y
704 here unless you have verified that your setup is not
705 affected by entries in the DMI blacklist. Required by PNP
709 bool "GART IOMMU support" if EXPERT
712 depends on X86_64 && PCI && AMD_NB
714 Support for full DMA access of devices with 32bit memory access only
715 on systems with more than 3GB. This is usually needed for USB,
716 sound, many IDE/SATA chipsets and some other devices.
717 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
718 based hardware IOMMU and a software bounce buffer based IOMMU used
719 on Intel systems and as fallback.
720 The code is only active when needed (enough memory and limited
721 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
725 bool "IBM Calgary IOMMU support"
727 depends on X86_64 && PCI && EXPERIMENTAL
729 Support for hardware IOMMUs in IBM's xSeries x366 and x460
730 systems. Needed to run systems with more than 3GB of memory
731 properly with 32-bit PCI devices that do not support DAC
732 (Double Address Cycle). Calgary also supports bus level
733 isolation, where all DMAs pass through the IOMMU. This
734 prevents them from going anywhere except their intended
735 destination. This catches hard-to-find kernel bugs and
736 mis-behaving drivers and devices that do not use the DMA-API
737 properly to set up their DMA buffers. The IOMMU can be
738 turned off at boot time with the iommu=off parameter.
739 Normally the kernel will make the right choice by itself.
742 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
744 prompt "Should Calgary be enabled by default?"
745 depends on CALGARY_IOMMU
747 Should Calgary be enabled by default? if you choose 'y', Calgary
748 will be used (if it exists). If you choose 'n', Calgary will not be
749 used even if it exists. If you choose 'n' and would like to use
750 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
753 # need this always selected by IOMMU for the VIA workaround
757 Support for software bounce buffers used on x86-64 systems
758 which don't have a hardware IOMMU (e.g. the current generation
759 of Intel's x86-64 CPUs). Using this PCI devices which can only
760 access 32-bits of memory can be used on systems with more than
761 3 GB of memory. If unsure, say Y.
764 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
767 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
768 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
769 select CPUMASK_OFFSTACK
771 Enable maximum number of CPUS and NUMA Nodes for this architecture.
775 int "Maximum number of CPUs" if SMP && !MAXSMP
776 range 2 8 if SMP && X86_32 && !X86_BIGSMP
777 range 2 512 if SMP && !MAXSMP
779 default "4096" if MAXSMP
780 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
783 This allows you to specify the maximum number of CPUs which this
784 kernel will support. The maximum supported value is 512 and the
785 minimum value which makes sense is 2.
787 This is purely to save memory - each supported CPU adds
788 approximately eight kilobytes to the kernel image.
791 bool "SMT (Hyperthreading) scheduler support"
794 SMT scheduler support improves the CPU scheduler's decision making
795 when dealing with Intel Pentium 4 chips with HyperThreading at a
796 cost of slightly increased overhead in some places. If unsure say
801 prompt "Multi-core scheduler support"
804 Multi-core scheduler support improves the CPU scheduler's decision
805 making when dealing with multi-core CPU chips at a cost of slightly
806 increased overhead in some places. If unsure say N here.
808 config IRQ_TIME_ACCOUNTING
809 bool "Fine granularity task level IRQ time accounting"
812 Select this option to enable fine granularity task irq time
813 accounting. This is done by reading a timestamp on each
814 transitions between softirq and hardirq state, so there can be a
815 small performance impact.
817 If in doubt, say N here.
819 source "kernel/Kconfig.preempt"
822 bool "Local APIC support on uniprocessors"
823 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
825 A local APIC (Advanced Programmable Interrupt Controller) is an
826 integrated interrupt controller in the CPU. If you have a single-CPU
827 system which has a processor with a local APIC, you can say Y here to
828 enable and use it. If you say Y here even though your machine doesn't
829 have a local APIC, then the kernel will still run with no slowdown at
830 all. The local APIC supports CPU-generated self-interrupts (timer,
831 performance counters), and the NMI watchdog which detects hard
835 bool "IO-APIC support on uniprocessors"
836 depends on X86_UP_APIC
838 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
839 SMP-capable replacement for PC-style interrupt controllers. Most
840 SMP systems and many recent uniprocessor systems have one.
842 If you have a single-CPU system with an IO-APIC, you can say Y here
843 to use it. If you say Y here even though your machine doesn't have
844 an IO-APIC, then the kernel will still run with no slowdown at all.
846 config X86_LOCAL_APIC
848 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
852 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
854 config X86_VISWS_APIC
856 depends on X86_32 && X86_VISWS
858 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
859 bool "Reroute for broken boot IRQs"
860 depends on X86_IO_APIC
862 This option enables a workaround that fixes a source of
863 spurious interrupts. This is recommended when threaded
864 interrupt handling is used on systems where the generation of
865 superfluous "boot interrupts" cannot be disabled.
867 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
868 entry in the chipset's IO-APIC is masked (as, e.g. the RT
869 kernel does during interrupt handling). On chipsets where this
870 boot IRQ generation cannot be disabled, this workaround keeps
871 the original IRQ line masked so that only the equivalent "boot
872 IRQ" is delivered to the CPUs. The workaround also tells the
873 kernel to set up the IRQ handler on the boot IRQ line. In this
874 way only one interrupt is delivered to the kernel. Otherwise
875 the spurious second interrupt may cause the kernel to bring
876 down (vital) interrupt lines.
878 Only affects "broken" chipsets. Interrupt sharing may be
879 increased on these systems.
882 bool "Machine Check / overheating reporting"
884 Machine Check support allows the processor to notify the
885 kernel if it detects a problem (e.g. overheating, data corruption).
886 The action the kernel takes depends on the severity of the problem,
887 ranging from warning messages to halting the machine.
891 prompt "Intel MCE features"
892 depends on X86_MCE && X86_LOCAL_APIC
894 Additional support for intel specific MCE features such as
899 prompt "AMD MCE features"
900 depends on X86_MCE && X86_LOCAL_APIC
902 Additional support for AMD specific MCE features such as
903 the DRAM Error Threshold.
905 config X86_ANCIENT_MCE
906 bool "Support for old Pentium 5 / WinChip machine checks"
907 depends on X86_32 && X86_MCE
909 Include support for machine check handling on old Pentium 5 or WinChip
910 systems. These typically need to be enabled explicitely on the command
913 config X86_MCE_THRESHOLD
914 depends on X86_MCE_AMD || X86_MCE_INTEL
917 config X86_MCE_INJECT
919 tristate "Machine check injector support"
921 Provide support for injecting machine checks for testing purposes.
922 If you don't know what a machine check is and you don't do kernel
923 QA it is safe to say n.
925 config X86_THERMAL_VECTOR
927 depends on X86_MCE_INTEL
930 bool "Enable VM86 support" if EXPERT
934 This option is required by programs like DOSEMU to run 16-bit legacy
935 code on X86 processors. It also may be needed by software like
936 XFree86 to initialize some video cards via BIOS. Disabling this
937 option saves about 6k.
940 tristate "Toshiba Laptop support"
943 This adds a driver to safely access the System Management Mode of
944 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
945 not work on models with a Phoenix BIOS. The System Management Mode
946 is used to set the BIOS and power saving options on Toshiba portables.
948 For information on utilities to make use of this driver see the
949 Toshiba Linux utilities web site at:
950 <http://www.buzzard.org.uk/toshiba/>.
952 Say Y if you intend to run this kernel on a Toshiba portable.
956 tristate "Dell laptop support"
959 This adds a driver to safely access the System Management Mode
960 of the CPU on the Dell Inspiron 8000. The System Management Mode
961 is used to read cpu temperature and cooling fan status and to
962 control the fans on the I8K portables.
964 This driver has been tested only on the Inspiron 8000 but it may
965 also work with other Dell laptops. You can force loading on other
966 models by passing the parameter `force=1' to the module. Use at
969 For information on utilities to make use of this driver see the
970 I8K Linux utilities web site at:
971 <http://people.debian.org/~dz/i8k/>
973 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
976 config X86_REBOOTFIXUPS
977 bool "Enable X86 board specific fixups for reboot"
980 This enables chipset and/or board specific fixups to be done
981 in order to get reboot to work correctly. This is only needed on
982 some combinations of hardware and BIOS. The symptom, for which
983 this config is intended, is when reboot ends with a stalled/hung
986 Currently, the only fixup is for the Geode machines using
987 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
989 Say Y if you want to enable the fixup. Currently, it's safe to
990 enable this option even if you don't need it.
994 tristate "/dev/cpu/microcode - microcode support"
997 If you say Y here, you will be able to update the microcode on
998 certain Intel and AMD processors. The Intel support is for the
999 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
1000 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
1001 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
1002 You will obviously need the actual microcode binary data itself
1003 which is not shipped with the Linux kernel.
1005 This option selects the general module only, you need to select
1006 at least one vendor specific module as well.
1008 To compile this driver as a module, choose M here: the
1009 module will be called microcode.
1011 config MICROCODE_INTEL
1012 bool "Intel microcode patch loading support"
1013 depends on MICROCODE
1017 This options enables microcode patch loading support for Intel
1020 For latest news and information on obtaining all the required
1021 Intel ingredients for this driver, check:
1022 <http://www.urbanmyth.org/microcode/>.
1024 config MICROCODE_AMD
1025 bool "AMD microcode patch loading support"
1026 depends on MICROCODE
1029 If you select this option, microcode patch loading support for AMD
1030 processors will be enabled.
1032 config MICROCODE_OLD_INTERFACE
1034 depends on MICROCODE
1037 tristate "/dev/cpu/*/msr - Model-specific register support"
1039 This device gives privileged processes access to the x86
1040 Model-Specific Registers (MSRs). It is a character device with
1041 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1042 MSR accesses are directed to a specific CPU on multi-processor
1046 tristate "/dev/cpu/*/cpuid - CPU information support"
1048 This device gives processes access to the x86 CPUID instruction to
1049 be executed on a specific processor. It is a character device
1050 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1054 prompt "High Memory Support"
1055 default HIGHMEM64G if X86_NUMAQ
1061 depends on !X86_NUMAQ
1063 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1064 However, the address space of 32-bit x86 processors is only 4
1065 Gigabytes large. That means that, if you have a large amount of
1066 physical memory, not all of it can be "permanently mapped" by the
1067 kernel. The physical memory that's not permanently mapped is called
1070 If you are compiling a kernel which will never run on a machine with
1071 more than 1 Gigabyte total physical RAM, answer "off" here (default
1072 choice and suitable for most users). This will result in a "3GB/1GB"
1073 split: 3GB are mapped so that each process sees a 3GB virtual memory
1074 space and the remaining part of the 4GB virtual memory space is used
1075 by the kernel to permanently map as much physical memory as
1078 If the machine has between 1 and 4 Gigabytes physical RAM, then
1081 If more than 4 Gigabytes is used then answer "64GB" here. This
1082 selection turns Intel PAE (Physical Address Extension) mode on.
1083 PAE implements 3-level paging on IA32 processors. PAE is fully
1084 supported by Linux, PAE mode is implemented on all recent Intel
1085 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1086 then the kernel will not boot on CPUs that don't support PAE!
1088 The actual amount of total physical memory will either be
1089 auto detected or can be forced by using a kernel command line option
1090 such as "mem=256M". (Try "man bootparam" or see the documentation of
1091 your boot loader (lilo or loadlin) about how to pass options to the
1092 kernel at boot time.)
1094 If unsure, say "off".
1098 depends on !X86_NUMAQ
1100 Select this if you have a 32-bit processor and between 1 and 4
1101 gigabytes of physical RAM.
1105 depends on !M386 && !M486
1108 Select this if you have a 32-bit processor and more than 4
1109 gigabytes of physical RAM.
1114 depends on EXPERIMENTAL
1115 prompt "Memory split" if EXPERT
1119 Select the desired split between kernel and user memory.
1121 If the address range available to the kernel is less than the
1122 physical memory installed, the remaining memory will be available
1123 as "high memory". Accessing high memory is a little more costly
1124 than low memory, as it needs to be mapped into the kernel first.
1125 Note that increasing the kernel address space limits the range
1126 available to user programs, making the address space there
1127 tighter. Selecting anything other than the default 3G/1G split
1128 will also likely make your kernel incompatible with binary-only
1131 If you are not absolutely sure what you are doing, leave this
1135 bool "3G/1G user/kernel split"
1136 config VMSPLIT_3G_OPT
1138 bool "3G/1G user/kernel split (for full 1G low memory)"
1140 bool "2G/2G user/kernel split"
1141 config VMSPLIT_2G_OPT
1143 bool "2G/2G user/kernel split (for full 2G low memory)"
1145 bool "1G/3G user/kernel split"
1150 default 0xB0000000 if VMSPLIT_3G_OPT
1151 default 0x80000000 if VMSPLIT_2G
1152 default 0x78000000 if VMSPLIT_2G_OPT
1153 default 0x40000000 if VMSPLIT_1G
1159 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1162 bool "PAE (Physical Address Extension) Support"
1163 depends on X86_32 && !HIGHMEM4G
1165 PAE is required for NX support, and furthermore enables
1166 larger swapspace support for non-overcommit purposes. It
1167 has the cost of more pagetable lookup overhead, and also
1168 consumes more pagetable space per process.
1170 config ARCH_PHYS_ADDR_T_64BIT
1171 def_bool X86_64 || X86_PAE
1173 config ARCH_DMA_ADDR_T_64BIT
1174 def_bool X86_64 || HIGHMEM64G
1176 config DIRECT_GBPAGES
1177 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1181 Allow the kernel linear mapping to use 1GB pages on CPUs that
1182 support it. This can improve the kernel's performance a tiny bit by
1183 reducing TLB pressure. If in doubt, say "Y".
1185 # Common NUMA Features
1187 bool "Numa Memory Allocation and Scheduler Support"
1189 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1190 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1192 Enable NUMA (Non Uniform Memory Access) support.
1194 The kernel will try to allocate memory used by a CPU on the
1195 local memory controller of the CPU and add some more
1196 NUMA awareness to the kernel.
1198 For 64-bit this is recommended if the system is Intel Core i7
1199 (or later), AMD Opteron, or EM64T NUMA.
1201 For 32-bit this is only needed on (rare) 32-bit-only platforms
1202 that support NUMA topologies, such as NUMAQ / Summit, or if you
1203 boot a 32-bit kernel on a 64-bit NUMA platform.
1205 Otherwise, you should say N.
1207 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1208 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1212 prompt "Old style AMD Opteron NUMA detection"
1213 depends on X86_64 && NUMA && PCI
1215 Enable AMD NUMA node topology detection. You should say Y here if
1216 you have a multi processor AMD system. This uses an old method to
1217 read the NUMA configuration directly from the builtin Northbridge
1218 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1219 which also takes priority if both are compiled in.
1221 config X86_64_ACPI_NUMA
1223 prompt "ACPI NUMA detection"
1224 depends on X86_64 && NUMA && ACPI && PCI
1227 Enable ACPI SRAT based node topology detection.
1229 # Some NUMA nodes have memory ranges that span
1230 # other nodes. Even though a pfn is valid and
1231 # between a node's start and end pfns, it may not
1232 # reside on that node. See memmap_init_zone()
1234 config NODES_SPAN_OTHER_NODES
1236 depends on X86_64_ACPI_NUMA
1239 bool "NUMA emulation"
1242 Enable NUMA emulation. A flat machine will be split
1243 into virtual nodes when booted with "numa=fake=N", where N is the
1244 number of nodes. This is only useful for debugging.
1247 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1249 default "10" if MAXSMP
1250 default "6" if X86_64
1251 default "4" if X86_NUMAQ
1253 depends on NEED_MULTIPLE_NODES
1255 Specify the maximum number of NUMA Nodes available on the target
1256 system. Increases memory reserved to accommodate various tables.
1258 config HAVE_ARCH_BOOTMEM
1260 depends on X86_32 && NUMA
1262 config HAVE_ARCH_ALLOC_REMAP
1264 depends on X86_32 && NUMA
1266 config ARCH_HAVE_MEMORY_PRESENT
1268 depends on X86_32 && DISCONTIGMEM
1270 config NEED_NODE_MEMMAP_SIZE
1272 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1274 config ARCH_FLATMEM_ENABLE
1276 depends on X86_32 && !NUMA
1278 config ARCH_DISCONTIGMEM_ENABLE
1280 depends on NUMA && X86_32
1282 config ARCH_DISCONTIGMEM_DEFAULT
1284 depends on NUMA && X86_32
1286 config ARCH_SPARSEMEM_ENABLE
1288 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1289 select SPARSEMEM_STATIC if X86_32
1290 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1292 config ARCH_SPARSEMEM_DEFAULT
1296 config ARCH_SELECT_MEMORY_MODEL
1298 depends on ARCH_SPARSEMEM_ENABLE
1300 config ARCH_MEMORY_PROBE
1302 depends on MEMORY_HOTPLUG
1304 config ARCH_PROC_KCORE_TEXT
1306 depends on X86_64 && PROC_KCORE
1308 config ILLEGAL_POINTER_VALUE
1311 default 0xdead000000000000 if X86_64
1316 bool "Allocate 3rd-level pagetables from highmem"
1319 The VM uses one page table entry for each page of physical memory.
1320 For systems with a lot of RAM, this can be wasteful of precious
1321 low memory. Setting this option will put user-space page table
1322 entries in high memory.
1324 config X86_CHECK_BIOS_CORRUPTION
1325 bool "Check for low memory corruption"
1327 Periodically check for memory corruption in low memory, which
1328 is suspected to be caused by BIOS. Even when enabled in the
1329 configuration, it is disabled at runtime. Enable it by
1330 setting "memory_corruption_check=1" on the kernel command
1331 line. By default it scans the low 64k of memory every 60
1332 seconds; see the memory_corruption_check_size and
1333 memory_corruption_check_period parameters in
1334 Documentation/kernel-parameters.txt to adjust this.
1336 When enabled with the default parameters, this option has
1337 almost no overhead, as it reserves a relatively small amount
1338 of memory and scans it infrequently. It both detects corruption
1339 and prevents it from affecting the running system.
1341 It is, however, intended as a diagnostic tool; if repeatable
1342 BIOS-originated corruption always affects the same memory,
1343 you can use memmap= to prevent the kernel from using that
1346 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1347 bool "Set the default setting of memory_corruption_check"
1348 depends on X86_CHECK_BIOS_CORRUPTION
1351 Set whether the default state of memory_corruption_check is
1354 config X86_RESERVE_LOW
1355 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1359 Specify the amount of low memory to reserve for the BIOS.
1361 The first page contains BIOS data structures that the kernel
1362 must not use, so that page must always be reserved.
1364 By default we reserve the first 64K of physical RAM, as a
1365 number of BIOSes are known to corrupt that memory range
1366 during events such as suspend/resume or monitor cable
1367 insertion, so it must not be used by the kernel.
1369 You can set this to 4 if you are absolutely sure that you
1370 trust the BIOS to get all its memory reservations and usages
1371 right. If you know your BIOS have problems beyond the
1372 default 64K area, you can set this to 640 to avoid using the
1373 entire low memory range.
1375 If you have doubts about the BIOS (e.g. suspend/resume does
1376 not work or there's kernel crashes after certain hardware
1377 hotplug events) then you might want to enable
1378 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1379 typical corruption patterns.
1381 Leave this to the default value of 64 if you are unsure.
1383 config MATH_EMULATION
1385 prompt "Math emulation" if X86_32
1387 Linux can emulate a math coprocessor (used for floating point
1388 operations) if you don't have one. 486DX and Pentium processors have
1389 a math coprocessor built in, 486SX and 386 do not, unless you added
1390 a 487DX or 387, respectively. (The messages during boot time can
1391 give you some hints here ["man dmesg"].) Everyone needs either a
1392 coprocessor or this emulation.
1394 If you don't have a math coprocessor, you need to say Y here; if you
1395 say Y here even though you have a coprocessor, the coprocessor will
1396 be used nevertheless. (This behavior can be changed with the kernel
1397 command line option "no387", which comes handy if your coprocessor
1398 is broken. Try "man bootparam" or see the documentation of your boot
1399 loader (lilo or loadlin) about how to pass options to the kernel at
1400 boot time.) This means that it is a good idea to say Y here if you
1401 intend to use this kernel on different machines.
1403 More information about the internals of the Linux math coprocessor
1404 emulation can be found in <file:arch/x86/math-emu/README>.
1406 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1407 kernel, it won't hurt.
1411 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1413 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1414 the Memory Type Range Registers (MTRRs) may be used to control
1415 processor access to memory ranges. This is most useful if you have
1416 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1417 allows bus write transfers to be combined into a larger transfer
1418 before bursting over the PCI/AGP bus. This can increase performance
1419 of image write operations 2.5 times or more. Saying Y here creates a
1420 /proc/mtrr file which may be used to manipulate your processor's
1421 MTRRs. Typically the X server should use this.
1423 This code has a reasonably generic interface so that similar
1424 control registers on other processors can be easily supported
1427 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1428 Registers (ARRs) which provide a similar functionality to MTRRs. For
1429 these, the ARRs are used to emulate the MTRRs.
1430 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1431 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1432 write-combining. All of these processors are supported by this code
1433 and it makes sense to say Y here if you have one of them.
1435 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1436 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1437 can lead to all sorts of problems, so it's good to say Y here.
1439 You can safely say Y even if your machine doesn't have MTRRs, you'll
1440 just add about 9 KB to your kernel.
1442 See <file:Documentation/x86/mtrr.txt> for more information.
1444 config MTRR_SANITIZER
1446 prompt "MTRR cleanup support"
1449 Convert MTRR layout from continuous to discrete, so X drivers can
1450 add writeback entries.
1452 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1453 The largest mtrr entry size for a continuous block can be set with
1458 config MTRR_SANITIZER_ENABLE_DEFAULT
1459 int "MTRR cleanup enable value (0-1)"
1462 depends on MTRR_SANITIZER
1464 Enable mtrr cleanup default value
1466 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1467 int "MTRR cleanup spare reg num (0-7)"
1470 depends on MTRR_SANITIZER
1472 mtrr cleanup spare entries default, it can be changed via
1473 mtrr_spare_reg_nr=N on the kernel command line.
1477 prompt "x86 PAT support" if EXPERT
1480 Use PAT attributes to setup page level cache control.
1482 PATs are the modern equivalents of MTRRs and are much more
1483 flexible than MTRRs.
1485 Say N here if you see bootup problems (boot crash, boot hang,
1486 spontaneous reboots) or a non-working video driver.
1490 config ARCH_USES_PG_UNCACHED
1496 prompt "x86 architectural random number generator" if EXPERT
1498 Enable the x86 architectural RDRAND instruction
1499 (Intel Bull Mountain technology) to generate random numbers.
1500 If supported, this is a high bandwidth, cryptographically
1501 secure hardware random number generator.
1504 bool "EFI runtime service support"
1507 This enables the kernel to use EFI runtime services that are
1508 available (such as the EFI variable services).
1510 This option is only useful on systems that have EFI firmware.
1511 In addition, you should use the latest ELILO loader available
1512 at <http://elilo.sourceforge.net> in order to take advantage
1513 of EFI runtime services. However, even with this option, the
1514 resultant kernel should continue to boot on existing non-EFI
1518 bool "EFI stub support"
1521 This kernel feature allows a bzImage to be loaded directly
1522 by EFI firmware without the use of a bootloader.
1526 prompt "Enable seccomp to safely compute untrusted bytecode"
1528 This kernel feature is useful for number crunching applications
1529 that may need to compute untrusted bytecode during their
1530 execution. By using pipes or other transports made available to
1531 the process as file descriptors supporting the read/write
1532 syscalls, it's possible to isolate those applications in
1533 their own address space using seccomp. Once seccomp is
1534 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1535 and the task is only allowed to execute a few safe syscalls
1536 defined by each seccomp mode.
1538 If unsure, say Y. Only embedded should say N here.
1540 config CC_STACKPROTECTOR
1541 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1543 This option turns on the -fstack-protector GCC feature. This
1544 feature puts, at the beginning of functions, a canary value on
1545 the stack just before the return address, and validates
1546 the value just before actually returning. Stack based buffer
1547 overflows (that need to overwrite this return address) now also
1548 overwrite the canary, which gets detected and the attack is then
1549 neutralized via a kernel panic.
1551 This feature requires gcc version 4.2 or above, or a distribution
1552 gcc with the feature backported. Older versions are automatically
1553 detected and for those versions, this configuration option is
1554 ignored. (and a warning is printed during bootup)
1556 source kernel/Kconfig.hz
1559 bool "kexec system call"
1561 kexec is a system call that implements the ability to shutdown your
1562 current kernel, and to start another kernel. It is like a reboot
1563 but it is independent of the system firmware. And like a reboot
1564 you can start any kernel with it, not just Linux.
1566 The name comes from the similarity to the exec system call.
1568 It is an ongoing process to be certain the hardware in a machine
1569 is properly shutdown, so do not be surprised if this code does not
1570 initially work for you. It may help to enable device hotplugging
1571 support. As of this writing the exact hardware interface is
1572 strongly in flux, so no good recommendation can be made.
1575 bool "kernel crash dumps"
1576 depends on X86_64 || (X86_32 && HIGHMEM)
1578 Generate crash dump after being started by kexec.
1579 This should be normally only set in special crash dump kernels
1580 which are loaded in the main kernel with kexec-tools into
1581 a specially reserved region and then later executed after
1582 a crash by kdump/kexec. The crash dump kernel must be compiled
1583 to a memory address not used by the main kernel or BIOS using
1584 PHYSICAL_START, or it must be built as a relocatable image
1585 (CONFIG_RELOCATABLE=y).
1586 For more details see Documentation/kdump/kdump.txt
1589 bool "kexec jump (EXPERIMENTAL)"
1590 depends on EXPERIMENTAL
1591 depends on KEXEC && HIBERNATION
1593 Jump between original kernel and kexeced kernel and invoke
1594 code in physical address mode via KEXEC
1596 config PHYSICAL_START
1597 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1600 This gives the physical address where the kernel is loaded.
1602 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1603 bzImage will decompress itself to above physical address and
1604 run from there. Otherwise, bzImage will run from the address where
1605 it has been loaded by the boot loader and will ignore above physical
1608 In normal kdump cases one does not have to set/change this option
1609 as now bzImage can be compiled as a completely relocatable image
1610 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1611 address. This option is mainly useful for the folks who don't want
1612 to use a bzImage for capturing the crash dump and want to use a
1613 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1614 to be specifically compiled to run from a specific memory area
1615 (normally a reserved region) and this option comes handy.
1617 So if you are using bzImage for capturing the crash dump,
1618 leave the value here unchanged to 0x1000000 and set
1619 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1620 for capturing the crash dump change this value to start of
1621 the reserved region. In other words, it can be set based on
1622 the "X" value as specified in the "crashkernel=YM@XM"
1623 command line boot parameter passed to the panic-ed
1624 kernel. Please take a look at Documentation/kdump/kdump.txt
1625 for more details about crash dumps.
1627 Usage of bzImage for capturing the crash dump is recommended as
1628 one does not have to build two kernels. Same kernel can be used
1629 as production kernel and capture kernel. Above option should have
1630 gone away after relocatable bzImage support is introduced. But it
1631 is present because there are users out there who continue to use
1632 vmlinux for dump capture. This option should go away down the
1635 Don't change this unless you know what you are doing.
1638 bool "Build a relocatable kernel"
1641 This builds a kernel image that retains relocation information
1642 so it can be loaded someplace besides the default 1MB.
1643 The relocations tend to make the kernel binary about 10% larger,
1644 but are discarded at runtime.
1646 One use is for the kexec on panic case where the recovery kernel
1647 must live at a different physical address than the primary
1650 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1651 it has been loaded at and the compile time physical address
1652 (CONFIG_PHYSICAL_START) is ignored.
1654 # Relocation on x86-32 needs some additional build support
1655 config X86_NEED_RELOCS
1657 depends on X86_32 && RELOCATABLE
1659 config PHYSICAL_ALIGN
1660 hex "Alignment value to which kernel should be aligned" if X86_32
1662 range 0x2000 0x1000000
1664 This value puts the alignment restrictions on physical address
1665 where kernel is loaded and run from. Kernel is compiled for an
1666 address which meets above alignment restriction.
1668 If bootloader loads the kernel at a non-aligned address and
1669 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1670 address aligned to above value and run from there.
1672 If bootloader loads the kernel at a non-aligned address and
1673 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1674 load address and decompress itself to the address it has been
1675 compiled for and run from there. The address for which kernel is
1676 compiled already meets above alignment restrictions. Hence the
1677 end result is that kernel runs from a physical address meeting
1678 above alignment restrictions.
1680 Don't change this unless you know what you are doing.
1683 bool "Support for hot-pluggable CPUs"
1684 depends on SMP && HOTPLUG
1686 Say Y here to allow turning CPUs off and on. CPUs can be
1687 controlled through /sys/devices/system/cpu.
1688 ( Note: power management support will enable this option
1689 automatically on SMP systems. )
1690 Say N if you want to disable CPU hotplug.
1694 prompt "Compat VDSO support"
1695 depends on X86_32 || IA32_EMULATION
1697 Map the 32-bit VDSO to the predictable old-style address too.
1699 Say N here if you are running a sufficiently recent glibc
1700 version (2.3.3 or later), to remove the high-mapped
1701 VDSO mapping and to exclusively use the randomized VDSO.
1706 bool "Built-in kernel command line"
1708 Allow for specifying boot arguments to the kernel at
1709 build time. On some systems (e.g. embedded ones), it is
1710 necessary or convenient to provide some or all of the
1711 kernel boot arguments with the kernel itself (that is,
1712 to not rely on the boot loader to provide them.)
1714 To compile command line arguments into the kernel,
1715 set this option to 'Y', then fill in the
1716 the boot arguments in CONFIG_CMDLINE.
1718 Systems with fully functional boot loaders (i.e. non-embedded)
1719 should leave this option set to 'N'.
1722 string "Built-in kernel command string"
1723 depends on CMDLINE_BOOL
1726 Enter arguments here that should be compiled into the kernel
1727 image and used at boot time. If the boot loader provides a
1728 command line at boot time, it is appended to this string to
1729 form the full kernel command line, when the system boots.
1731 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1732 change this behavior.
1734 In most cases, the command line (whether built-in or provided
1735 by the boot loader) should specify the device for the root
1738 config CMDLINE_OVERRIDE
1739 bool "Built-in command line overrides boot loader arguments"
1740 depends on CMDLINE_BOOL
1742 Set this option to 'Y' to have the kernel ignore the boot loader
1743 command line, and use ONLY the built-in command line.
1745 This is used to work around broken boot loaders. This should
1746 be set to 'N' under normal conditions.
1750 config ARCH_ENABLE_MEMORY_HOTPLUG
1752 depends on X86_64 || (X86_32 && HIGHMEM)
1754 config ARCH_ENABLE_MEMORY_HOTREMOVE
1756 depends on MEMORY_HOTPLUG
1758 config USE_PERCPU_NUMA_NODE_ID
1762 menu "Power management and ACPI options"
1764 config ARCH_HIBERNATION_HEADER
1766 depends on X86_64 && HIBERNATION
1768 source "kernel/power/Kconfig"
1770 source "drivers/acpi/Kconfig"
1772 source "drivers/sfi/Kconfig"
1779 tristate "APM (Advanced Power Management) BIOS support"
1780 depends on X86_32 && PM_SLEEP
1782 APM is a BIOS specification for saving power using several different
1783 techniques. This is mostly useful for battery powered laptops with
1784 APM compliant BIOSes. If you say Y here, the system time will be
1785 reset after a RESUME operation, the /proc/apm device will provide
1786 battery status information, and user-space programs will receive
1787 notification of APM "events" (e.g. battery status change).
1789 If you select "Y" here, you can disable actual use of the APM
1790 BIOS by passing the "apm=off" option to the kernel at boot time.
1792 Note that the APM support is almost completely disabled for
1793 machines with more than one CPU.
1795 In order to use APM, you will need supporting software. For location
1796 and more information, read <file:Documentation/power/apm-acpi.txt>
1797 and the Battery Powered Linux mini-HOWTO, available from
1798 <http://www.tldp.org/docs.html#howto>.
1800 This driver does not spin down disk drives (see the hdparm(8)
1801 manpage ("man 8 hdparm") for that), and it doesn't turn off
1802 VESA-compliant "green" monitors.
1804 This driver does not support the TI 4000M TravelMate and the ACER
1805 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1806 desktop machines also don't have compliant BIOSes, and this driver
1807 may cause those machines to panic during the boot phase.
1809 Generally, if you don't have a battery in your machine, there isn't
1810 much point in using this driver and you should say N. If you get
1811 random kernel OOPSes or reboots that don't seem to be related to
1812 anything, try disabling/enabling this option (or disabling/enabling
1815 Some other things you should try when experiencing seemingly random,
1818 1) make sure that you have enough swap space and that it is
1820 2) pass the "no-hlt" option to the kernel
1821 3) switch on floating point emulation in the kernel and pass
1822 the "no387" option to the kernel
1823 4) pass the "floppy=nodma" option to the kernel
1824 5) pass the "mem=4M" option to the kernel (thereby disabling
1825 all but the first 4 MB of RAM)
1826 6) make sure that the CPU is not over clocked.
1827 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1828 8) disable the cache from your BIOS settings
1829 9) install a fan for the video card or exchange video RAM
1830 10) install a better fan for the CPU
1831 11) exchange RAM chips
1832 12) exchange the motherboard.
1834 To compile this driver as a module, choose M here: the
1835 module will be called apm.
1839 config APM_IGNORE_USER_SUSPEND
1840 bool "Ignore USER SUSPEND"
1842 This option will ignore USER SUSPEND requests. On machines with a
1843 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1844 series notebooks, it is necessary to say Y because of a BIOS bug.
1846 config APM_DO_ENABLE
1847 bool "Enable PM at boot time"
1849 Enable APM features at boot time. From page 36 of the APM BIOS
1850 specification: "When disabled, the APM BIOS does not automatically
1851 power manage devices, enter the Standby State, enter the Suspend
1852 State, or take power saving steps in response to CPU Idle calls."
1853 This driver will make CPU Idle calls when Linux is idle (unless this
1854 feature is turned off -- see "Do CPU IDLE calls", below). This
1855 should always save battery power, but more complicated APM features
1856 will be dependent on your BIOS implementation. You may need to turn
1857 this option off if your computer hangs at boot time when using APM
1858 support, or if it beeps continuously instead of suspending. Turn
1859 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1860 T400CDT. This is off by default since most machines do fine without
1864 bool "Make CPU Idle calls when idle"
1866 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1867 On some machines, this can activate improved power savings, such as
1868 a slowed CPU clock rate, when the machine is idle. These idle calls
1869 are made after the idle loop has run for some length of time (e.g.,
1870 333 mS). On some machines, this will cause a hang at boot time or
1871 whenever the CPU becomes idle. (On machines with more than one CPU,
1872 this option does nothing.)
1874 config APM_DISPLAY_BLANK
1875 bool "Enable console blanking using APM"
1877 Enable console blanking using the APM. Some laptops can use this to
1878 turn off the LCD backlight when the screen blanker of the Linux
1879 virtual console blanks the screen. Note that this is only used by
1880 the virtual console screen blanker, and won't turn off the backlight
1881 when using the X Window system. This also doesn't have anything to
1882 do with your VESA-compliant power-saving monitor. Further, this
1883 option doesn't work for all laptops -- it might not turn off your
1884 backlight at all, or it might print a lot of errors to the console,
1885 especially if you are using gpm.
1887 config APM_ALLOW_INTS
1888 bool "Allow interrupts during APM BIOS calls"
1890 Normally we disable external interrupts while we are making calls to
1891 the APM BIOS as a measure to lessen the effects of a badly behaving
1892 BIOS implementation. The BIOS should reenable interrupts if it
1893 needs to. Unfortunately, some BIOSes do not -- especially those in
1894 many of the newer IBM Thinkpads. If you experience hangs when you
1895 suspend, try setting this to Y. Otherwise, say N.
1899 source "drivers/cpufreq/Kconfig"
1901 source "drivers/cpuidle/Kconfig"
1903 source "drivers/idle/Kconfig"
1908 menu "Bus options (PCI etc.)"
1913 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1915 Find out whether you have a PCI motherboard. PCI is the name of a
1916 bus system, i.e. the way the CPU talks to the other stuff inside
1917 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1918 VESA. If you have PCI, say Y, otherwise N.
1921 prompt "PCI access mode"
1922 depends on X86_32 && PCI
1925 On PCI systems, the BIOS can be used to detect the PCI devices and
1926 determine their configuration. However, some old PCI motherboards
1927 have BIOS bugs and may crash if this is done. Also, some embedded
1928 PCI-based systems don't have any BIOS at all. Linux can also try to
1929 detect the PCI hardware directly without using the BIOS.
1931 With this option, you can specify how Linux should detect the
1932 PCI devices. If you choose "BIOS", the BIOS will be used,
1933 if you choose "Direct", the BIOS won't be used, and if you
1934 choose "MMConfig", then PCI Express MMCONFIG will be used.
1935 If you choose "Any", the kernel will try MMCONFIG, then the
1936 direct access method and falls back to the BIOS if that doesn't
1937 work. If unsure, go with the default, which is "Any".
1942 config PCI_GOMMCONFIG
1959 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1961 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1964 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1968 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1972 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1976 depends on PCI && XEN
1984 bool "Support mmconfig PCI config space access"
1985 depends on X86_64 && PCI && ACPI
1987 config PCI_CNB20LE_QUIRK
1988 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1990 depends on PCI && EXPERIMENTAL
1992 Read the PCI windows out of the CNB20LE host bridge. This allows
1993 PCI hotplug to work on systems with the CNB20LE chipset which do
1996 There's no public spec for this chipset, and this functionality
1997 is known to be incomplete.
1999 You should say N unless you know you need this.
2001 source "drivers/pci/pcie/Kconfig"
2003 source "drivers/pci/Kconfig"
2005 # x86_64 have no ISA slots, but can have ISA-style DMA.
2007 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2010 Enables ISA-style DMA support for devices requiring such controllers.
2018 Find out whether you have ISA slots on your motherboard. ISA is the
2019 name of a bus system, i.e. the way the CPU talks to the other stuff
2020 inside your box. Other bus systems are PCI, EISA, MicroChannel
2021 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2022 newer boards don't support it. If you have ISA, say Y, otherwise N.
2028 The Extended Industry Standard Architecture (EISA) bus was
2029 developed as an open alternative to the IBM MicroChannel bus.
2031 The EISA bus provided some of the features of the IBM MicroChannel
2032 bus while maintaining backward compatibility with cards made for
2033 the older ISA bus. The EISA bus saw limited use between 1988 and
2034 1995 when it was made obsolete by the PCI bus.
2036 Say Y here if you are building a kernel for an EISA-based machine.
2040 source "drivers/eisa/Kconfig"
2045 MicroChannel Architecture is found in some IBM PS/2 machines and
2046 laptops. It is a bus system similar to PCI or ISA. See
2047 <file:Documentation/mca.txt> (and especially the web page given
2048 there) before attempting to build an MCA bus kernel.
2050 source "drivers/mca/Kconfig"
2053 tristate "NatSemi SCx200 support"
2055 This provides basic support for National Semiconductor's
2056 (now AMD's) Geode processors. The driver probes for the
2057 PCI-IDs of several on-chip devices, so its a good dependency
2058 for other scx200_* drivers.
2060 If compiled as a module, the driver is named scx200.
2062 config SCx200HR_TIMER
2063 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2067 This driver provides a clocksource built upon the on-chip
2068 27MHz high-resolution timer. Its also a workaround for
2069 NSC Geode SC-1100's buggy TSC, which loses time when the
2070 processor goes idle (as is done by the scheduler). The
2071 other workaround is idle=poll boot option.
2074 bool "One Laptop Per Child support"
2080 Add support for detecting the unique features of the OLPC
2084 bool "OLPC XO-1 Power Management"
2085 depends on OLPC && MFD_CS5535 && PM_SLEEP
2088 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2091 bool "OLPC XO-1 Real Time Clock"
2092 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2094 Add support for the XO-1 real time clock, which can be used as a
2095 programmable wakeup source.
2098 bool "OLPC XO-1 SCI extras"
2099 depends on OLPC && OLPC_XO1_PM
2104 Add support for SCI-based features of the OLPC XO-1 laptop:
2105 - EC-driven system wakeups
2109 - AC adapter status updates
2110 - Battery status updates
2112 config OLPC_XO15_SCI
2113 bool "OLPC XO-1.5 SCI extras"
2114 depends on OLPC && ACPI
2117 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2118 - EC-driven system wakeups
2119 - AC adapter status updates
2120 - Battery status updates
2123 bool "PCEngines ALIX System Support (LED setup)"
2126 This option enables system support for the PCEngines ALIX.
2127 At present this just sets up LEDs for GPIO control on
2128 ALIX2/3/6 boards. However, other system specific setup should
2131 Note: You must still enable the drivers for GPIO and LED support
2132 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2134 Note: You have to set alix.force=1 for boards with Award BIOS.
2140 depends on CPU_SUP_AMD && PCI
2142 source "drivers/pcmcia/Kconfig"
2144 source "drivers/pci/hotplug/Kconfig"
2147 bool "RapidIO support"
2151 If you say Y here, the kernel will include drivers and
2152 infrastructure code to support RapidIO interconnect devices.
2154 source "drivers/rapidio/Kconfig"
2159 menu "Executable file formats / Emulations"
2161 source "fs/Kconfig.binfmt"
2163 config IA32_EMULATION
2164 bool "IA32 Emulation"
2166 select COMPAT_BINFMT_ELF
2168 Include code to run 32-bit programs under a 64-bit kernel. You should
2169 likely turn this on, unless you're 100% sure that you don't have any
2170 32-bit programs left.
2173 tristate "IA32 a.out support"
2174 depends on IA32_EMULATION
2176 Support old a.out binaries in the 32bit emulation.
2180 depends on IA32_EMULATION
2182 config COMPAT_FOR_U64_ALIGNMENT
2186 config SYSVIPC_COMPAT
2188 depends on COMPAT && SYSVIPC
2192 depends on COMPAT && KEYS
2198 config HAVE_ATOMIC_IOMAP
2202 config HAVE_TEXT_POKE_SMP
2204 select STOP_MACHINE if SMP
2206 source "net/Kconfig"
2208 source "drivers/Kconfig"
2210 source "drivers/firmware/Kconfig"
2214 source "arch/x86/Kconfig.debug"
2216 source "security/Kconfig"
2218 source "crypto/Kconfig"
2220 source "arch/x86/kvm/Kconfig"
2222 source "lib/Kconfig"