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_ARCH_KMEMCHECK
64 select HAVE_USER_RETURN_NOTIFIER
65 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
66 select HAVE_ARCH_JUMP_LABEL
67 select HAVE_TEXT_POKE_SMP
68 select HAVE_GENERIC_HARDIRQS
69 select HAVE_SPARSE_IRQ
71 select GENERIC_FIND_FIRST_BIT
72 select GENERIC_IRQ_PROBE
73 select GENERIC_PENDING_IRQ if SMP
74 select GENERIC_IRQ_SHOW
75 select GENERIC_CLOCKEVENTS_MIN_ADJUST
76 select IRQ_FORCED_THREADING
77 select USE_GENERIC_SMP_HELPERS if SMP
78 select HAVE_BPF_JIT if (X86_64 && NET)
80 select ARCH_HAVE_NMI_SAFE_CMPXCHG
83 config INSTRUCTION_DECODER
84 def_bool (KPROBES || PERF_EVENTS)
88 default "elf32-i386" if X86_32
89 default "elf64-x86-64" if X86_64
93 default "arch/x86/configs/i386_defconfig" if X86_32
94 default "arch/x86/configs/x86_64_defconfig" if X86_64
96 config GENERIC_CMOS_UPDATE
99 config CLOCKSOURCE_WATCHDOG
102 config GENERIC_CLOCKEVENTS
105 config ARCH_CLOCKSOURCE_DATA
109 config GENERIC_CLOCKEVENTS_BROADCAST
111 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
113 config LOCKDEP_SUPPORT
116 config STACKTRACE_SUPPORT
119 config HAVE_LATENCYTOP_SUPPORT
126 bool "DMA memory allocation support" if EXPERT
129 DMA memory allocation support allows devices with less than 32-bit
130 addressing to allocate within the first 16MB of address space.
131 Disable if no such devices will be used.
138 config NEED_DMA_MAP_STATE
139 def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG)
141 config NEED_SG_DMA_LENGTH
144 config GENERIC_ISA_DMA
150 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
152 config GENERIC_BUG_RELATIVE_POINTERS
155 config GENERIC_HWEIGHT
161 config ARCH_MAY_HAVE_PC_FDC
164 config RWSEM_GENERIC_SPINLOCK
167 config RWSEM_XCHGADD_ALGORITHM
170 config ARCH_HAS_CPU_IDLE_WAIT
173 config GENERIC_CALIBRATE_DELAY
176 config GENERIC_TIME_VSYSCALL
180 config ARCH_HAS_CPU_RELAX
183 config ARCH_HAS_DEFAULT_IDLE
186 config ARCH_HAS_CACHE_LINE_SIZE
189 config HAVE_SETUP_PER_CPU_AREA
192 config NEED_PER_CPU_EMBED_FIRST_CHUNK
195 config NEED_PER_CPU_PAGE_FIRST_CHUNK
198 config ARCH_HIBERNATION_POSSIBLE
201 config ARCH_SUSPEND_POSSIBLE
212 config ARCH_SUPPORTS_OPTIMIZED_INLINING
215 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
218 config HAVE_INTEL_TXT
220 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
224 depends on X86_32 && SMP
228 depends on X86_64 && SMP
234 config X86_32_LAZY_GS
236 depends on X86_32 && !CC_STACKPROTECTOR
238 config ARCH_HWEIGHT_CFLAGS
240 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
241 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
246 config ARCH_CPU_PROBE_RELEASE
248 depends on HOTPLUG_CPU
250 source "init/Kconfig"
251 source "kernel/Kconfig.freezer"
253 menu "Processor type and features"
255 source "kernel/time/Kconfig"
258 bool "Symmetric multi-processing support"
260 This enables support for systems with more than one CPU. If you have
261 a system with only one CPU, like most personal computers, say N. If
262 you have a system with more than one CPU, say Y.
264 If you say N here, the kernel will run on single and multiprocessor
265 machines, but will use only one CPU of a multiprocessor machine. If
266 you say Y here, the kernel will run on many, but not all,
267 singleprocessor machines. On a singleprocessor machine, the kernel
268 will run faster if you say N here.
270 Note that if you say Y here and choose architecture "586" or
271 "Pentium" under "Processor family", the kernel will not work on 486
272 architectures. Similarly, multiprocessor kernels for the "PPro"
273 architecture may not work on all Pentium based boards.
275 People using multiprocessor machines who say Y here should also say
276 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
277 Management" code will be disabled if you say Y here.
279 See also <file:Documentation/x86/i386/IO-APIC.txt>,
280 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
281 <http://www.tldp.org/docs.html#howto>.
283 If you don't know what to do here, say N.
286 bool "Support x2apic"
287 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
289 This enables x2apic support on CPUs that have this feature.
291 This allows 32-bit apic IDs (so it can support very large systems),
292 and accesses the local apic via MSRs not via mmio.
294 If you don't know what to do here, say N.
297 bool "Enable MPS table" if ACPI
299 depends on X86_LOCAL_APIC
301 For old smp systems that do not have proper acpi support. Newer systems
302 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
305 bool "Support for big SMP systems with more than 8 CPUs"
306 depends on X86_32 && SMP
308 This option is needed for the systems that have more than 8 CPUs
311 config X86_EXTENDED_PLATFORM
312 bool "Support for extended (non-PC) x86 platforms"
315 If you disable this option then the kernel will only support
316 standard PC platforms. (which covers the vast majority of
319 If you enable this option then you'll be able to select support
320 for the following (non-PC) 32 bit x86 platforms:
324 SGI 320/540 (Visual Workstation)
325 Summit/EXA (IBM x440)
326 Unisys ES7000 IA32 series
327 Moorestown MID devices
329 If you have one of these systems, or if you want to build a
330 generic distribution kernel, say Y here - otherwise say N.
334 config X86_EXTENDED_PLATFORM
335 bool "Support for extended (non-PC) x86 platforms"
338 If you disable this option then the kernel will only support
339 standard PC platforms. (which covers the vast majority of
342 If you enable this option then you'll be able to select support
343 for the following (non-PC) 64 bit x86 platforms:
348 If you have one of these systems, or if you want to build a
349 generic distribution kernel, say Y here - otherwise say N.
351 # This is an alphabetically sorted list of 64 bit extended platforms
352 # Please maintain the alphabetic order if and when there are additions
354 bool "Numascale NumaChip"
356 depends on X86_EXTENDED_PLATFORM
359 depends on X86_X2APIC
360 depends on !EDAC_AMD64
362 Adds support for Numascale NumaChip large-SMP systems. Needed to
363 enable more than ~168 cores.
364 If you don't have one of these, you should say N here.
368 select PARAVIRT_GUEST
370 depends on X86_64 && PCI
371 depends on X86_EXTENDED_PLATFORM
373 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
374 supposed to run on these EM64T-based machines. Only choose this option
375 if you have one of these machines.
378 bool "SGI Ultraviolet"
380 depends on X86_EXTENDED_PLATFORM
382 depends on X86_X2APIC
384 This option is needed in order to support SGI Ultraviolet systems.
385 If you don't have one of these, you should say N here.
387 # Following is an alphabetically sorted list of 32 bit extended platforms
388 # Please maintain the alphabetic order if and when there are additions
391 bool "CE4100 TV platform"
393 depends on PCI_GODIRECT
395 depends on X86_EXTENDED_PLATFORM
396 select X86_REBOOTFIXUPS
398 select OF_EARLY_FLATTREE
400 Select for the Intel CE media processor (CE4100) SOC.
401 This option compiles in support for the CE4100 SOC for settop
402 boxes and media devices.
404 config X86_WANT_INTEL_MID
405 bool "Intel MID platform support"
407 depends on X86_EXTENDED_PLATFORM
409 Select to build a kernel capable of supporting Intel MID platform
410 systems which do not have the PCI legacy interfaces (Moorestown,
411 Medfield). If you are building for a PC class system say N here.
413 if X86_WANT_INTEL_MID
419 bool "Moorestown MID platform"
422 depends on X86_IO_APIC
430 select X86_PLATFORM_DEVICES
432 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
433 Internet Device(MID) platform. Moorestown consists of two chips:
434 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
435 Unlike standard x86 PCs, Moorestown does not have many legacy devices
436 nor standard legacy replacement devices/features. e.g. Moorestown does
437 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
440 bool "Medfield MID platform"
443 depends on X86_IO_APIC
451 select X86_PLATFORM_DEVICES
453 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
454 Internet Device(MID) platform.
455 Unlike standard x86 PCs, Medfield does not have many legacy devices
456 nor standard legacy replacement devices/features. e.g. Medfield does
457 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
462 bool "RDC R-321x SoC"
464 depends on X86_EXTENDED_PLATFORM
466 select X86_REBOOTFIXUPS
468 This option is needed for RDC R-321x system-on-chip, also known
470 If you don't have one of these chips, you should say N here.
472 config X86_32_NON_STANDARD
473 bool "Support non-standard 32-bit SMP architectures"
474 depends on X86_32 && SMP
475 depends on X86_EXTENDED_PLATFORM
477 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
478 subarchitectures. It is intended for a generic binary kernel.
479 if you select them all, kernel will probe it one by one. and will
482 # Alphabetically sorted list of Non standard 32 bit platforms
485 bool "NUMAQ (IBM/Sequent)"
486 depends on X86_32_NON_STANDARD
491 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
492 NUMA multiquad box. This changes the way that processors are
493 bootstrapped, and uses Clustered Logical APIC addressing mode instead
494 of Flat Logical. You will need a new lynxer.elf file to flash your
495 firmware with - send email to <Martin.Bligh@us.ibm.com>.
497 config X86_SUPPORTS_MEMORY_FAILURE
499 # MCE code calls memory_failure():
501 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
502 depends on !X86_NUMAQ
503 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
504 depends on X86_64 || !SPARSEMEM
505 select ARCH_SUPPORTS_MEMORY_FAILURE
508 bool "SGI 320/540 (Visual Workstation)"
509 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
510 depends on X86_32_NON_STANDARD
512 The SGI Visual Workstation series is an IA32-based workstation
513 based on SGI systems chips with some legacy PC hardware attached.
515 Say Y here to create a kernel to run on the SGI 320 or 540.
517 A kernel compiled for the Visual Workstation will run on general
518 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
521 bool "Summit/EXA (IBM x440)"
522 depends on X86_32_NON_STANDARD
524 This option is needed for IBM systems that use the Summit/EXA chipset.
525 In particular, it is needed for the x440.
528 bool "Unisys ES7000 IA32 series"
529 depends on X86_32_NON_STANDARD && X86_BIGSMP
531 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
532 supposed to run on an IA32-based Unisys ES7000 system.
535 tristate "Eurobraille/Iris poweroff module"
538 The Iris machines from EuroBraille do not have APM or ACPI support
539 to shut themselves down properly. A special I/O sequence is
540 needed to do so, which is what this module does at
543 This is only for Iris machines from EuroBraille.
547 config SCHED_OMIT_FRAME_POINTER
549 prompt "Single-depth WCHAN output"
552 Calculate simpler /proc/<PID>/wchan values. If this option
553 is disabled then wchan values will recurse back to the
554 caller function. This provides more accurate wchan values,
555 at the expense of slightly more scheduling overhead.
557 If in doubt, say "Y".
559 menuconfig PARAVIRT_GUEST
560 bool "Paravirtualized guest support"
562 Say Y here to get to see options related to running Linux under
563 various hypervisors. This option alone does not add any kernel code.
565 If you say N, all options in this submenu will be skipped and disabled.
569 config PARAVIRT_TIME_ACCOUNTING
570 bool "Paravirtual steal time accounting"
574 Select this option to enable fine granularity task steal time
575 accounting. Time spent executing other tasks in parallel with
576 the current vCPU is discounted from the vCPU power. To account for
577 that, there can be a small performance impact.
579 If in doubt, say N here.
581 source "arch/x86/xen/Kconfig"
584 bool "KVM paravirtualized clock"
586 select PARAVIRT_CLOCK
588 Turning on this option will allow you to run a paravirtualized clock
589 when running over the KVM hypervisor. Instead of relying on a PIT
590 (or probably other) emulation by the underlying device model, the host
591 provides the guest with timing infrastructure such as time of day, and
595 bool "KVM Guest support"
598 This option enables various optimizations for running under the KVM
601 source "arch/x86/lguest/Kconfig"
604 bool "Enable paravirtualization code"
606 This changes the kernel so it can modify itself when it is run
607 under a hypervisor, potentially improving performance significantly
608 over full virtualization. However, when run without a hypervisor
609 the kernel is theoretically slower and slightly larger.
611 config PARAVIRT_SPINLOCKS
612 bool "Paravirtualization layer for spinlocks"
613 depends on PARAVIRT && SMP && EXPERIMENTAL
615 Paravirtualized spinlocks allow a pvops backend to replace the
616 spinlock implementation with something virtualization-friendly
617 (for example, block the virtual CPU rather than spinning).
619 Unfortunately the downside is an up to 5% performance hit on
620 native kernels, with various workloads.
622 If you are unsure how to answer this question, answer N.
624 config PARAVIRT_CLOCK
629 config PARAVIRT_DEBUG
630 bool "paravirt-ops debugging"
631 depends on PARAVIRT && DEBUG_KERNEL
633 Enable to debug paravirt_ops internals. Specifically, BUG if
634 a paravirt_op is missing when it is called.
642 This option adds a kernel parameter 'memtest', which allows memtest
644 memtest=0, mean disabled; -- default
645 memtest=1, mean do 1 test pattern;
647 memtest=4, mean do 4 test patterns.
648 If you are unsure how to answer this question, answer N.
650 config X86_SUMMIT_NUMA
652 depends on X86_32 && NUMA && X86_32_NON_STANDARD
654 config X86_CYCLONE_TIMER
656 depends on X86_SUMMIT
658 source "arch/x86/Kconfig.cpu"
662 prompt "HPET Timer Support" if X86_32
664 Use the IA-PC HPET (High Precision Event Timer) to manage
665 time in preference to the PIT and RTC, if a HPET is
667 HPET is the next generation timer replacing legacy 8254s.
668 The HPET provides a stable time base on SMP
669 systems, unlike the TSC, but it is more expensive to access,
670 as it is off-chip. You can find the HPET spec at
671 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
673 You can safely choose Y here. However, HPET will only be
674 activated if the platform and the BIOS support this feature.
675 Otherwise the 8254 will be used for timing services.
677 Choose N to continue using the legacy 8254 timer.
679 config HPET_EMULATE_RTC
681 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
684 def_bool y if X86_INTEL_MID
685 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
687 depends on X86_INTEL_MID && SFI
689 APB timer is the replacement for 8254, HPET on X86 MID platforms.
690 The APBT provides a stable time base on SMP
691 systems, unlike the TSC, but it is more expensive to access,
692 as it is off-chip. APB timers are always running regardless of CPU
693 C states, they are used as per CPU clockevent device when possible.
695 # Mark as expert because too many people got it wrong.
696 # The code disables itself when not needed.
699 bool "Enable DMI scanning" if EXPERT
701 Enabled scanning of DMI to identify machine quirks. Say Y
702 here unless you have verified that your setup is not
703 affected by entries in the DMI blacklist. Required by PNP
707 bool "GART IOMMU support" if EXPERT
710 depends on X86_64 && PCI && AMD_NB
712 Support for full DMA access of devices with 32bit memory access only
713 on systems with more than 3GB. This is usually needed for USB,
714 sound, many IDE/SATA chipsets and some other devices.
715 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
716 based hardware IOMMU and a software bounce buffer based IOMMU used
717 on Intel systems and as fallback.
718 The code is only active when needed (enough memory and limited
719 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
723 bool "IBM Calgary IOMMU support"
725 depends on X86_64 && PCI && EXPERIMENTAL
727 Support for hardware IOMMUs in IBM's xSeries x366 and x460
728 systems. Needed to run systems with more than 3GB of memory
729 properly with 32-bit PCI devices that do not support DAC
730 (Double Address Cycle). Calgary also supports bus level
731 isolation, where all DMAs pass through the IOMMU. This
732 prevents them from going anywhere except their intended
733 destination. This catches hard-to-find kernel bugs and
734 mis-behaving drivers and devices that do not use the DMA-API
735 properly to set up their DMA buffers. The IOMMU can be
736 turned off at boot time with the iommu=off parameter.
737 Normally the kernel will make the right choice by itself.
740 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
742 prompt "Should Calgary be enabled by default?"
743 depends on CALGARY_IOMMU
745 Should Calgary be enabled by default? if you choose 'y', Calgary
746 will be used (if it exists). If you choose 'n', Calgary will not be
747 used even if it exists. If you choose 'n' and would like to use
748 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
751 # need this always selected by IOMMU for the VIA workaround
755 Support for software bounce buffers used on x86-64 systems
756 which don't have a hardware IOMMU (e.g. the current generation
757 of Intel's x86-64 CPUs). Using this PCI devices which can only
758 access 32-bits of memory can be used on systems with more than
759 3 GB of memory. If unsure, say Y.
762 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
765 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
766 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
767 select CPUMASK_OFFSTACK
769 Enable maximum number of CPUS and NUMA Nodes for this architecture.
773 int "Maximum number of CPUs" if SMP && !MAXSMP
774 range 2 8 if SMP && X86_32 && !X86_BIGSMP
775 range 2 512 if SMP && !MAXSMP
777 default "4096" if MAXSMP
778 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
781 This allows you to specify the maximum number of CPUs which this
782 kernel will support. The maximum supported value is 512 and the
783 minimum value which makes sense is 2.
785 This is purely to save memory - each supported CPU adds
786 approximately eight kilobytes to the kernel image.
789 bool "SMT (Hyperthreading) scheduler support"
792 SMT scheduler support improves the CPU scheduler's decision making
793 when dealing with Intel Pentium 4 chips with HyperThreading at a
794 cost of slightly increased overhead in some places. If unsure say
799 prompt "Multi-core scheduler support"
802 Multi-core scheduler support improves the CPU scheduler's decision
803 making when dealing with multi-core CPU chips at a cost of slightly
804 increased overhead in some places. If unsure say N here.
806 config IRQ_TIME_ACCOUNTING
807 bool "Fine granularity task level IRQ time accounting"
810 Select this option to enable fine granularity task irq time
811 accounting. This is done by reading a timestamp on each
812 transitions between softirq and hardirq state, so there can be a
813 small performance impact.
815 If in doubt, say N here.
817 source "kernel/Kconfig.preempt"
820 bool "Local APIC support on uniprocessors"
821 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
823 A local APIC (Advanced Programmable Interrupt Controller) is an
824 integrated interrupt controller in the CPU. If you have a single-CPU
825 system which has a processor with a local APIC, you can say Y here to
826 enable and use it. If you say Y here even though your machine doesn't
827 have a local APIC, then the kernel will still run with no slowdown at
828 all. The local APIC supports CPU-generated self-interrupts (timer,
829 performance counters), and the NMI watchdog which detects hard
833 bool "IO-APIC support on uniprocessors"
834 depends on X86_UP_APIC
836 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
837 SMP-capable replacement for PC-style interrupt controllers. Most
838 SMP systems and many recent uniprocessor systems have one.
840 If you have a single-CPU system with an IO-APIC, you can say Y here
841 to use it. If you say Y here even though your machine doesn't have
842 an IO-APIC, then the kernel will still run with no slowdown at all.
844 config X86_LOCAL_APIC
846 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
850 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
852 config X86_VISWS_APIC
854 depends on X86_32 && X86_VISWS
856 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
857 bool "Reroute for broken boot IRQs"
858 depends on X86_IO_APIC
860 This option enables a workaround that fixes a source of
861 spurious interrupts. This is recommended when threaded
862 interrupt handling is used on systems where the generation of
863 superfluous "boot interrupts" cannot be disabled.
865 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
866 entry in the chipset's IO-APIC is masked (as, e.g. the RT
867 kernel does during interrupt handling). On chipsets where this
868 boot IRQ generation cannot be disabled, this workaround keeps
869 the original IRQ line masked so that only the equivalent "boot
870 IRQ" is delivered to the CPUs. The workaround also tells the
871 kernel to set up the IRQ handler on the boot IRQ line. In this
872 way only one interrupt is delivered to the kernel. Otherwise
873 the spurious second interrupt may cause the kernel to bring
874 down (vital) interrupt lines.
876 Only affects "broken" chipsets. Interrupt sharing may be
877 increased on these systems.
880 bool "Machine Check / overheating reporting"
882 Machine Check support allows the processor to notify the
883 kernel if it detects a problem (e.g. overheating, data corruption).
884 The action the kernel takes depends on the severity of the problem,
885 ranging from warning messages to halting the machine.
889 prompt "Intel MCE features"
890 depends on X86_MCE && X86_LOCAL_APIC
892 Additional support for intel specific MCE features such as
897 prompt "AMD MCE features"
898 depends on X86_MCE && X86_LOCAL_APIC
900 Additional support for AMD specific MCE features such as
901 the DRAM Error Threshold.
903 config X86_ANCIENT_MCE
904 bool "Support for old Pentium 5 / WinChip machine checks"
905 depends on X86_32 && X86_MCE
907 Include support for machine check handling on old Pentium 5 or WinChip
908 systems. These typically need to be enabled explicitely on the command
911 config X86_MCE_THRESHOLD
912 depends on X86_MCE_AMD || X86_MCE_INTEL
915 config X86_MCE_INJECT
917 tristate "Machine check injector support"
919 Provide support for injecting machine checks for testing purposes.
920 If you don't know what a machine check is and you don't do kernel
921 QA it is safe to say n.
923 config X86_THERMAL_VECTOR
925 depends on X86_MCE_INTEL
928 bool "Enable VM86 support" if EXPERT
932 This option is required by programs like DOSEMU to run 16-bit legacy
933 code on X86 processors. It also may be needed by software like
934 XFree86 to initialize some video cards via BIOS. Disabling this
935 option saves about 6k.
938 tristate "Toshiba Laptop support"
941 This adds a driver to safely access the System Management Mode of
942 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
943 not work on models with a Phoenix BIOS. The System Management Mode
944 is used to set the BIOS and power saving options on Toshiba portables.
946 For information on utilities to make use of this driver see the
947 Toshiba Linux utilities web site at:
948 <http://www.buzzard.org.uk/toshiba/>.
950 Say Y if you intend to run this kernel on a Toshiba portable.
954 tristate "Dell laptop support"
957 This adds a driver to safely access the System Management Mode
958 of the CPU on the Dell Inspiron 8000. The System Management Mode
959 is used to read cpu temperature and cooling fan status and to
960 control the fans on the I8K portables.
962 This driver has been tested only on the Inspiron 8000 but it may
963 also work with other Dell laptops. You can force loading on other
964 models by passing the parameter `force=1' to the module. Use at
967 For information on utilities to make use of this driver see the
968 I8K Linux utilities web site at:
969 <http://people.debian.org/~dz/i8k/>
971 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
974 config X86_REBOOTFIXUPS
975 bool "Enable X86 board specific fixups for reboot"
978 This enables chipset and/or board specific fixups to be done
979 in order to get reboot to work correctly. This is only needed on
980 some combinations of hardware and BIOS. The symptom, for which
981 this config is intended, is when reboot ends with a stalled/hung
984 Currently, the only fixup is for the Geode machines using
985 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
987 Say Y if you want to enable the fixup. Currently, it's safe to
988 enable this option even if you don't need it.
992 tristate "/dev/cpu/microcode - microcode support"
995 If you say Y here, you will be able to update the microcode on
996 certain Intel and AMD processors. The Intel support is for the
997 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
998 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
999 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
1000 You will obviously need the actual microcode binary data itself
1001 which is not shipped with the Linux kernel.
1003 This option selects the general module only, you need to select
1004 at least one vendor specific module as well.
1006 To compile this driver as a module, choose M here: the
1007 module will be called microcode.
1009 config MICROCODE_INTEL
1010 bool "Intel microcode patch loading support"
1011 depends on MICROCODE
1015 This options enables microcode patch loading support for Intel
1018 For latest news and information on obtaining all the required
1019 Intel ingredients for this driver, check:
1020 <http://www.urbanmyth.org/microcode/>.
1022 config MICROCODE_AMD
1023 bool "AMD microcode patch loading support"
1024 depends on MICROCODE
1027 If you select this option, microcode patch loading support for AMD
1028 processors will be enabled.
1030 config MICROCODE_OLD_INTERFACE
1032 depends on MICROCODE
1035 tristate "/dev/cpu/*/msr - Model-specific register support"
1037 This device gives privileged processes access to the x86
1038 Model-Specific Registers (MSRs). It is a character device with
1039 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1040 MSR accesses are directed to a specific CPU on multi-processor
1044 tristate "/dev/cpu/*/cpuid - CPU information support"
1046 This device gives processes access to the x86 CPUID instruction to
1047 be executed on a specific processor. It is a character device
1048 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1052 prompt "High Memory Support"
1053 default HIGHMEM64G if X86_NUMAQ
1059 depends on !X86_NUMAQ
1061 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1062 However, the address space of 32-bit x86 processors is only 4
1063 Gigabytes large. That means that, if you have a large amount of
1064 physical memory, not all of it can be "permanently mapped" by the
1065 kernel. The physical memory that's not permanently mapped is called
1068 If you are compiling a kernel which will never run on a machine with
1069 more than 1 Gigabyte total physical RAM, answer "off" here (default
1070 choice and suitable for most users). This will result in a "3GB/1GB"
1071 split: 3GB are mapped so that each process sees a 3GB virtual memory
1072 space and the remaining part of the 4GB virtual memory space is used
1073 by the kernel to permanently map as much physical memory as
1076 If the machine has between 1 and 4 Gigabytes physical RAM, then
1079 If more than 4 Gigabytes is used then answer "64GB" here. This
1080 selection turns Intel PAE (Physical Address Extension) mode on.
1081 PAE implements 3-level paging on IA32 processors. PAE is fully
1082 supported by Linux, PAE mode is implemented on all recent Intel
1083 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1084 then the kernel will not boot on CPUs that don't support PAE!
1086 The actual amount of total physical memory will either be
1087 auto detected or can be forced by using a kernel command line option
1088 such as "mem=256M". (Try "man bootparam" or see the documentation of
1089 your boot loader (lilo or loadlin) about how to pass options to the
1090 kernel at boot time.)
1092 If unsure, say "off".
1096 depends on !X86_NUMAQ
1098 Select this if you have a 32-bit processor and between 1 and 4
1099 gigabytes of physical RAM.
1103 depends on !M386 && !M486
1106 Select this if you have a 32-bit processor and more than 4
1107 gigabytes of physical RAM.
1112 depends on EXPERIMENTAL
1113 prompt "Memory split" if EXPERT
1117 Select the desired split between kernel and user memory.
1119 If the address range available to the kernel is less than the
1120 physical memory installed, the remaining memory will be available
1121 as "high memory". Accessing high memory is a little more costly
1122 than low memory, as it needs to be mapped into the kernel first.
1123 Note that increasing the kernel address space limits the range
1124 available to user programs, making the address space there
1125 tighter. Selecting anything other than the default 3G/1G split
1126 will also likely make your kernel incompatible with binary-only
1129 If you are not absolutely sure what you are doing, leave this
1133 bool "3G/1G user/kernel split"
1134 config VMSPLIT_3G_OPT
1136 bool "3G/1G user/kernel split (for full 1G low memory)"
1138 bool "2G/2G user/kernel split"
1139 config VMSPLIT_2G_OPT
1141 bool "2G/2G user/kernel split (for full 2G low memory)"
1143 bool "1G/3G user/kernel split"
1148 default 0xB0000000 if VMSPLIT_3G_OPT
1149 default 0x80000000 if VMSPLIT_2G
1150 default 0x78000000 if VMSPLIT_2G_OPT
1151 default 0x40000000 if VMSPLIT_1G
1157 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1160 bool "PAE (Physical Address Extension) Support"
1161 depends on X86_32 && !HIGHMEM4G
1163 PAE is required for NX support, and furthermore enables
1164 larger swapspace support for non-overcommit purposes. It
1165 has the cost of more pagetable lookup overhead, and also
1166 consumes more pagetable space per process.
1168 config ARCH_PHYS_ADDR_T_64BIT
1169 def_bool X86_64 || X86_PAE
1171 config ARCH_DMA_ADDR_T_64BIT
1172 def_bool X86_64 || HIGHMEM64G
1174 config DIRECT_GBPAGES
1175 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1179 Allow the kernel linear mapping to use 1GB pages on CPUs that
1180 support it. This can improve the kernel's performance a tiny bit by
1181 reducing TLB pressure. If in doubt, say "Y".
1183 # Common NUMA Features
1185 bool "Numa Memory Allocation and Scheduler Support"
1187 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1188 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1190 Enable NUMA (Non Uniform Memory Access) support.
1192 The kernel will try to allocate memory used by a CPU on the
1193 local memory controller of the CPU and add some more
1194 NUMA awareness to the kernel.
1196 For 64-bit this is recommended if the system is Intel Core i7
1197 (or later), AMD Opteron, or EM64T NUMA.
1199 For 32-bit this is only needed on (rare) 32-bit-only platforms
1200 that support NUMA topologies, such as NUMAQ / Summit, or if you
1201 boot a 32-bit kernel on a 64-bit NUMA platform.
1203 Otherwise, you should say N.
1205 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1206 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1210 prompt "Old style AMD Opteron NUMA detection"
1211 depends on X86_64 && NUMA && PCI
1213 Enable AMD NUMA node topology detection. You should say Y here if
1214 you have a multi processor AMD system. This uses an old method to
1215 read the NUMA configuration directly from the builtin Northbridge
1216 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1217 which also takes priority if both are compiled in.
1219 config X86_64_ACPI_NUMA
1221 prompt "ACPI NUMA detection"
1222 depends on X86_64 && NUMA && ACPI && PCI
1225 Enable ACPI SRAT based node topology detection.
1227 # Some NUMA nodes have memory ranges that span
1228 # other nodes. Even though a pfn is valid and
1229 # between a node's start and end pfns, it may not
1230 # reside on that node. See memmap_init_zone()
1232 config NODES_SPAN_OTHER_NODES
1234 depends on X86_64_ACPI_NUMA
1237 bool "NUMA emulation"
1240 Enable NUMA emulation. A flat machine will be split
1241 into virtual nodes when booted with "numa=fake=N", where N is the
1242 number of nodes. This is only useful for debugging.
1245 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1247 default "10" if MAXSMP
1248 default "6" if X86_64
1249 default "4" if X86_NUMAQ
1251 depends on NEED_MULTIPLE_NODES
1253 Specify the maximum number of NUMA Nodes available on the target
1254 system. Increases memory reserved to accommodate various tables.
1256 config HAVE_ARCH_BOOTMEM
1258 depends on X86_32 && NUMA
1260 config HAVE_ARCH_ALLOC_REMAP
1262 depends on X86_32 && NUMA
1264 config ARCH_HAVE_MEMORY_PRESENT
1266 depends on X86_32 && DISCONTIGMEM
1268 config NEED_NODE_MEMMAP_SIZE
1270 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1272 config ARCH_FLATMEM_ENABLE
1274 depends on X86_32 && !NUMA
1276 config ARCH_DISCONTIGMEM_ENABLE
1278 depends on NUMA && X86_32
1280 config ARCH_DISCONTIGMEM_DEFAULT
1282 depends on NUMA && X86_32
1284 config ARCH_SPARSEMEM_ENABLE
1286 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1287 select SPARSEMEM_STATIC if X86_32
1288 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1290 config ARCH_SPARSEMEM_DEFAULT
1294 config ARCH_SELECT_MEMORY_MODEL
1296 depends on ARCH_SPARSEMEM_ENABLE
1298 config ARCH_MEMORY_PROBE
1300 depends on MEMORY_HOTPLUG
1302 config ARCH_PROC_KCORE_TEXT
1304 depends on X86_64 && PROC_KCORE
1306 config ILLEGAL_POINTER_VALUE
1309 default 0xdead000000000000 if X86_64
1314 bool "Allocate 3rd-level pagetables from highmem"
1317 The VM uses one page table entry for each page of physical memory.
1318 For systems with a lot of RAM, this can be wasteful of precious
1319 low memory. Setting this option will put user-space page table
1320 entries in high memory.
1322 config X86_CHECK_BIOS_CORRUPTION
1323 bool "Check for low memory corruption"
1325 Periodically check for memory corruption in low memory, which
1326 is suspected to be caused by BIOS. Even when enabled in the
1327 configuration, it is disabled at runtime. Enable it by
1328 setting "memory_corruption_check=1" on the kernel command
1329 line. By default it scans the low 64k of memory every 60
1330 seconds; see the memory_corruption_check_size and
1331 memory_corruption_check_period parameters in
1332 Documentation/kernel-parameters.txt to adjust this.
1334 When enabled with the default parameters, this option has
1335 almost no overhead, as it reserves a relatively small amount
1336 of memory and scans it infrequently. It both detects corruption
1337 and prevents it from affecting the running system.
1339 It is, however, intended as a diagnostic tool; if repeatable
1340 BIOS-originated corruption always affects the same memory,
1341 you can use memmap= to prevent the kernel from using that
1344 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1345 bool "Set the default setting of memory_corruption_check"
1346 depends on X86_CHECK_BIOS_CORRUPTION
1349 Set whether the default state of memory_corruption_check is
1352 config X86_RESERVE_LOW
1353 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1357 Specify the amount of low memory to reserve for the BIOS.
1359 The first page contains BIOS data structures that the kernel
1360 must not use, so that page must always be reserved.
1362 By default we reserve the first 64K of physical RAM, as a
1363 number of BIOSes are known to corrupt that memory range
1364 during events such as suspend/resume or monitor cable
1365 insertion, so it must not be used by the kernel.
1367 You can set this to 4 if you are absolutely sure that you
1368 trust the BIOS to get all its memory reservations and usages
1369 right. If you know your BIOS have problems beyond the
1370 default 64K area, you can set this to 640 to avoid using the
1371 entire low memory range.
1373 If you have doubts about the BIOS (e.g. suspend/resume does
1374 not work or there's kernel crashes after certain hardware
1375 hotplug events) then you might want to enable
1376 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1377 typical corruption patterns.
1379 Leave this to the default value of 64 if you are unsure.
1381 config MATH_EMULATION
1383 prompt "Math emulation" if X86_32
1385 Linux can emulate a math coprocessor (used for floating point
1386 operations) if you don't have one. 486DX and Pentium processors have
1387 a math coprocessor built in, 486SX and 386 do not, unless you added
1388 a 487DX or 387, respectively. (The messages during boot time can
1389 give you some hints here ["man dmesg"].) Everyone needs either a
1390 coprocessor or this emulation.
1392 If you don't have a math coprocessor, you need to say Y here; if you
1393 say Y here even though you have a coprocessor, the coprocessor will
1394 be used nevertheless. (This behavior can be changed with the kernel
1395 command line option "no387", which comes handy if your coprocessor
1396 is broken. Try "man bootparam" or see the documentation of your boot
1397 loader (lilo or loadlin) about how to pass options to the kernel at
1398 boot time.) This means that it is a good idea to say Y here if you
1399 intend to use this kernel on different machines.
1401 More information about the internals of the Linux math coprocessor
1402 emulation can be found in <file:arch/x86/math-emu/README>.
1404 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1405 kernel, it won't hurt.
1409 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1411 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1412 the Memory Type Range Registers (MTRRs) may be used to control
1413 processor access to memory ranges. This is most useful if you have
1414 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1415 allows bus write transfers to be combined into a larger transfer
1416 before bursting over the PCI/AGP bus. This can increase performance
1417 of image write operations 2.5 times or more. Saying Y here creates a
1418 /proc/mtrr file which may be used to manipulate your processor's
1419 MTRRs. Typically the X server should use this.
1421 This code has a reasonably generic interface so that similar
1422 control registers on other processors can be easily supported
1425 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1426 Registers (ARRs) which provide a similar functionality to MTRRs. For
1427 these, the ARRs are used to emulate the MTRRs.
1428 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1429 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1430 write-combining. All of these processors are supported by this code
1431 and it makes sense to say Y here if you have one of them.
1433 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1434 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1435 can lead to all sorts of problems, so it's good to say Y here.
1437 You can safely say Y even if your machine doesn't have MTRRs, you'll
1438 just add about 9 KB to your kernel.
1440 See <file:Documentation/x86/mtrr.txt> for more information.
1442 config MTRR_SANITIZER
1444 prompt "MTRR cleanup support"
1447 Convert MTRR layout from continuous to discrete, so X drivers can
1448 add writeback entries.
1450 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1451 The largest mtrr entry size for a continuous block can be set with
1456 config MTRR_SANITIZER_ENABLE_DEFAULT
1457 int "MTRR cleanup enable value (0-1)"
1460 depends on MTRR_SANITIZER
1462 Enable mtrr cleanup default value
1464 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1465 int "MTRR cleanup spare reg num (0-7)"
1468 depends on MTRR_SANITIZER
1470 mtrr cleanup spare entries default, it can be changed via
1471 mtrr_spare_reg_nr=N on the kernel command line.
1475 prompt "x86 PAT support" if EXPERT
1478 Use PAT attributes to setup page level cache control.
1480 PATs are the modern equivalents of MTRRs and are much more
1481 flexible than MTRRs.
1483 Say N here if you see bootup problems (boot crash, boot hang,
1484 spontaneous reboots) or a non-working video driver.
1488 config ARCH_USES_PG_UNCACHED
1494 prompt "x86 architectural random number generator" if EXPERT
1496 Enable the x86 architectural RDRAND instruction
1497 (Intel Bull Mountain technology) to generate random numbers.
1498 If supported, this is a high bandwidth, cryptographically
1499 secure hardware random number generator.
1502 bool "EFI runtime service support"
1505 This enables the kernel to use EFI runtime services that are
1506 available (such as the EFI variable services).
1508 This option is only useful on systems that have EFI firmware.
1509 In addition, you should use the latest ELILO loader available
1510 at <http://elilo.sourceforge.net> in order to take advantage
1511 of EFI runtime services. However, even with this option, the
1512 resultant kernel should continue to boot on existing non-EFI
1516 bool "EFI stub support"
1519 This kernel feature allows a bzImage to be loaded directly
1520 by EFI firmware without the use of a bootloader.
1524 prompt "Enable seccomp to safely compute untrusted bytecode"
1526 This kernel feature is useful for number crunching applications
1527 that may need to compute untrusted bytecode during their
1528 execution. By using pipes or other transports made available to
1529 the process as file descriptors supporting the read/write
1530 syscalls, it's possible to isolate those applications in
1531 their own address space using seccomp. Once seccomp is
1532 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1533 and the task is only allowed to execute a few safe syscalls
1534 defined by each seccomp mode.
1536 If unsure, say Y. Only embedded should say N here.
1538 config CC_STACKPROTECTOR
1539 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1541 This option turns on the -fstack-protector GCC feature. This
1542 feature puts, at the beginning of functions, a canary value on
1543 the stack just before the return address, and validates
1544 the value just before actually returning. Stack based buffer
1545 overflows (that need to overwrite this return address) now also
1546 overwrite the canary, which gets detected and the attack is then
1547 neutralized via a kernel panic.
1549 This feature requires gcc version 4.2 or above, or a distribution
1550 gcc with the feature backported. Older versions are automatically
1551 detected and for those versions, this configuration option is
1552 ignored. (and a warning is printed during bootup)
1554 source kernel/Kconfig.hz
1557 bool "kexec system call"
1559 kexec is a system call that implements the ability to shutdown your
1560 current kernel, and to start another kernel. It is like a reboot
1561 but it is independent of the system firmware. And like a reboot
1562 you can start any kernel with it, not just Linux.
1564 The name comes from the similarity to the exec system call.
1566 It is an ongoing process to be certain the hardware in a machine
1567 is properly shutdown, so do not be surprised if this code does not
1568 initially work for you. It may help to enable device hotplugging
1569 support. As of this writing the exact hardware interface is
1570 strongly in flux, so no good recommendation can be made.
1573 bool "kernel crash dumps"
1574 depends on X86_64 || (X86_32 && HIGHMEM)
1576 Generate crash dump after being started by kexec.
1577 This should be normally only set in special crash dump kernels
1578 which are loaded in the main kernel with kexec-tools into
1579 a specially reserved region and then later executed after
1580 a crash by kdump/kexec. The crash dump kernel must be compiled
1581 to a memory address not used by the main kernel or BIOS using
1582 PHYSICAL_START, or it must be built as a relocatable image
1583 (CONFIG_RELOCATABLE=y).
1584 For more details see Documentation/kdump/kdump.txt
1587 bool "kexec jump (EXPERIMENTAL)"
1588 depends on EXPERIMENTAL
1589 depends on KEXEC && HIBERNATION
1591 Jump between original kernel and kexeced kernel and invoke
1592 code in physical address mode via KEXEC
1594 config PHYSICAL_START
1595 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1598 This gives the physical address where the kernel is loaded.
1600 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1601 bzImage will decompress itself to above physical address and
1602 run from there. Otherwise, bzImage will run from the address where
1603 it has been loaded by the boot loader and will ignore above physical
1606 In normal kdump cases one does not have to set/change this option
1607 as now bzImage can be compiled as a completely relocatable image
1608 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1609 address. This option is mainly useful for the folks who don't want
1610 to use a bzImage for capturing the crash dump and want to use a
1611 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1612 to be specifically compiled to run from a specific memory area
1613 (normally a reserved region) and this option comes handy.
1615 So if you are using bzImage for capturing the crash dump,
1616 leave the value here unchanged to 0x1000000 and set
1617 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1618 for capturing the crash dump change this value to start of
1619 the reserved region. In other words, it can be set based on
1620 the "X" value as specified in the "crashkernel=YM@XM"
1621 command line boot parameter passed to the panic-ed
1622 kernel. Please take a look at Documentation/kdump/kdump.txt
1623 for more details about crash dumps.
1625 Usage of bzImage for capturing the crash dump is recommended as
1626 one does not have to build two kernels. Same kernel can be used
1627 as production kernel and capture kernel. Above option should have
1628 gone away after relocatable bzImage support is introduced. But it
1629 is present because there are users out there who continue to use
1630 vmlinux for dump capture. This option should go away down the
1633 Don't change this unless you know what you are doing.
1636 bool "Build a relocatable kernel"
1639 This builds a kernel image that retains relocation information
1640 so it can be loaded someplace besides the default 1MB.
1641 The relocations tend to make the kernel binary about 10% larger,
1642 but are discarded at runtime.
1644 One use is for the kexec on panic case where the recovery kernel
1645 must live at a different physical address than the primary
1648 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1649 it has been loaded at and the compile time physical address
1650 (CONFIG_PHYSICAL_START) is ignored.
1652 # Relocation on x86-32 needs some additional build support
1653 config X86_NEED_RELOCS
1655 depends on X86_32 && RELOCATABLE
1657 config PHYSICAL_ALIGN
1658 hex "Alignment value to which kernel should be aligned" if X86_32
1660 range 0x2000 0x1000000
1662 This value puts the alignment restrictions on physical address
1663 where kernel is loaded and run from. Kernel is compiled for an
1664 address which meets above alignment restriction.
1666 If bootloader loads the kernel at a non-aligned address and
1667 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1668 address aligned to above value and run from there.
1670 If bootloader loads the kernel at a non-aligned address and
1671 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1672 load address and decompress itself to the address it has been
1673 compiled for and run from there. The address for which kernel is
1674 compiled already meets above alignment restrictions. Hence the
1675 end result is that kernel runs from a physical address meeting
1676 above alignment restrictions.
1678 Don't change this unless you know what you are doing.
1681 bool "Support for hot-pluggable CPUs"
1682 depends on SMP && HOTPLUG
1684 Say Y here to allow turning CPUs off and on. CPUs can be
1685 controlled through /sys/devices/system/cpu.
1686 ( Note: power management support will enable this option
1687 automatically on SMP systems. )
1688 Say N if you want to disable CPU hotplug.
1692 prompt "Compat VDSO support"
1693 depends on X86_32 || IA32_EMULATION
1695 Map the 32-bit VDSO to the predictable old-style address too.
1697 Say N here if you are running a sufficiently recent glibc
1698 version (2.3.3 or later), to remove the high-mapped
1699 VDSO mapping and to exclusively use the randomized VDSO.
1704 bool "Built-in kernel command line"
1706 Allow for specifying boot arguments to the kernel at
1707 build time. On some systems (e.g. embedded ones), it is
1708 necessary or convenient to provide some or all of the
1709 kernel boot arguments with the kernel itself (that is,
1710 to not rely on the boot loader to provide them.)
1712 To compile command line arguments into the kernel,
1713 set this option to 'Y', then fill in the
1714 the boot arguments in CONFIG_CMDLINE.
1716 Systems with fully functional boot loaders (i.e. non-embedded)
1717 should leave this option set to 'N'.
1720 string "Built-in kernel command string"
1721 depends on CMDLINE_BOOL
1724 Enter arguments here that should be compiled into the kernel
1725 image and used at boot time. If the boot loader provides a
1726 command line at boot time, it is appended to this string to
1727 form the full kernel command line, when the system boots.
1729 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1730 change this behavior.
1732 In most cases, the command line (whether built-in or provided
1733 by the boot loader) should specify the device for the root
1736 config CMDLINE_OVERRIDE
1737 bool "Built-in command line overrides boot loader arguments"
1738 depends on CMDLINE_BOOL
1740 Set this option to 'Y' to have the kernel ignore the boot loader
1741 command line, and use ONLY the built-in command line.
1743 This is used to work around broken boot loaders. This should
1744 be set to 'N' under normal conditions.
1748 config ARCH_ENABLE_MEMORY_HOTPLUG
1750 depends on X86_64 || (X86_32 && HIGHMEM)
1752 config ARCH_ENABLE_MEMORY_HOTREMOVE
1754 depends on MEMORY_HOTPLUG
1756 config USE_PERCPU_NUMA_NODE_ID
1760 menu "Power management and ACPI options"
1762 config ARCH_HIBERNATION_HEADER
1764 depends on X86_64 && HIBERNATION
1766 source "kernel/power/Kconfig"
1768 source "drivers/acpi/Kconfig"
1770 source "drivers/sfi/Kconfig"
1777 tristate "APM (Advanced Power Management) BIOS support"
1778 depends on X86_32 && PM_SLEEP
1780 APM is a BIOS specification for saving power using several different
1781 techniques. This is mostly useful for battery powered laptops with
1782 APM compliant BIOSes. If you say Y here, the system time will be
1783 reset after a RESUME operation, the /proc/apm device will provide
1784 battery status information, and user-space programs will receive
1785 notification of APM "events" (e.g. battery status change).
1787 If you select "Y" here, you can disable actual use of the APM
1788 BIOS by passing the "apm=off" option to the kernel at boot time.
1790 Note that the APM support is almost completely disabled for
1791 machines with more than one CPU.
1793 In order to use APM, you will need supporting software. For location
1794 and more information, read <file:Documentation/power/apm-acpi.txt>
1795 and the Battery Powered Linux mini-HOWTO, available from
1796 <http://www.tldp.org/docs.html#howto>.
1798 This driver does not spin down disk drives (see the hdparm(8)
1799 manpage ("man 8 hdparm") for that), and it doesn't turn off
1800 VESA-compliant "green" monitors.
1802 This driver does not support the TI 4000M TravelMate and the ACER
1803 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1804 desktop machines also don't have compliant BIOSes, and this driver
1805 may cause those machines to panic during the boot phase.
1807 Generally, if you don't have a battery in your machine, there isn't
1808 much point in using this driver and you should say N. If you get
1809 random kernel OOPSes or reboots that don't seem to be related to
1810 anything, try disabling/enabling this option (or disabling/enabling
1813 Some other things you should try when experiencing seemingly random,
1816 1) make sure that you have enough swap space and that it is
1818 2) pass the "no-hlt" option to the kernel
1819 3) switch on floating point emulation in the kernel and pass
1820 the "no387" option to the kernel
1821 4) pass the "floppy=nodma" option to the kernel
1822 5) pass the "mem=4M" option to the kernel (thereby disabling
1823 all but the first 4 MB of RAM)
1824 6) make sure that the CPU is not over clocked.
1825 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1826 8) disable the cache from your BIOS settings
1827 9) install a fan for the video card or exchange video RAM
1828 10) install a better fan for the CPU
1829 11) exchange RAM chips
1830 12) exchange the motherboard.
1832 To compile this driver as a module, choose M here: the
1833 module will be called apm.
1837 config APM_IGNORE_USER_SUSPEND
1838 bool "Ignore USER SUSPEND"
1840 This option will ignore USER SUSPEND requests. On machines with a
1841 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1842 series notebooks, it is necessary to say Y because of a BIOS bug.
1844 config APM_DO_ENABLE
1845 bool "Enable PM at boot time"
1847 Enable APM features at boot time. From page 36 of the APM BIOS
1848 specification: "When disabled, the APM BIOS does not automatically
1849 power manage devices, enter the Standby State, enter the Suspend
1850 State, or take power saving steps in response to CPU Idle calls."
1851 This driver will make CPU Idle calls when Linux is idle (unless this
1852 feature is turned off -- see "Do CPU IDLE calls", below). This
1853 should always save battery power, but more complicated APM features
1854 will be dependent on your BIOS implementation. You may need to turn
1855 this option off if your computer hangs at boot time when using APM
1856 support, or if it beeps continuously instead of suspending. Turn
1857 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1858 T400CDT. This is off by default since most machines do fine without
1862 bool "Make CPU Idle calls when idle"
1864 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1865 On some machines, this can activate improved power savings, such as
1866 a slowed CPU clock rate, when the machine is idle. These idle calls
1867 are made after the idle loop has run for some length of time (e.g.,
1868 333 mS). On some machines, this will cause a hang at boot time or
1869 whenever the CPU becomes idle. (On machines with more than one CPU,
1870 this option does nothing.)
1872 config APM_DISPLAY_BLANK
1873 bool "Enable console blanking using APM"
1875 Enable console blanking using the APM. Some laptops can use this to
1876 turn off the LCD backlight when the screen blanker of the Linux
1877 virtual console blanks the screen. Note that this is only used by
1878 the virtual console screen blanker, and won't turn off the backlight
1879 when using the X Window system. This also doesn't have anything to
1880 do with your VESA-compliant power-saving monitor. Further, this
1881 option doesn't work for all laptops -- it might not turn off your
1882 backlight at all, or it might print a lot of errors to the console,
1883 especially if you are using gpm.
1885 config APM_ALLOW_INTS
1886 bool "Allow interrupts during APM BIOS calls"
1888 Normally we disable external interrupts while we are making calls to
1889 the APM BIOS as a measure to lessen the effects of a badly behaving
1890 BIOS implementation. The BIOS should reenable interrupts if it
1891 needs to. Unfortunately, some BIOSes do not -- especially those in
1892 many of the newer IBM Thinkpads. If you experience hangs when you
1893 suspend, try setting this to Y. Otherwise, say N.
1897 source "drivers/cpufreq/Kconfig"
1899 source "drivers/cpuidle/Kconfig"
1901 source "drivers/idle/Kconfig"
1906 menu "Bus options (PCI etc.)"
1911 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1913 Find out whether you have a PCI motherboard. PCI is the name of a
1914 bus system, i.e. the way the CPU talks to the other stuff inside
1915 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1916 VESA. If you have PCI, say Y, otherwise N.
1919 prompt "PCI access mode"
1920 depends on X86_32 && PCI
1923 On PCI systems, the BIOS can be used to detect the PCI devices and
1924 determine their configuration. However, some old PCI motherboards
1925 have BIOS bugs and may crash if this is done. Also, some embedded
1926 PCI-based systems don't have any BIOS at all. Linux can also try to
1927 detect the PCI hardware directly without using the BIOS.
1929 With this option, you can specify how Linux should detect the
1930 PCI devices. If you choose "BIOS", the BIOS will be used,
1931 if you choose "Direct", the BIOS won't be used, and if you
1932 choose "MMConfig", then PCI Express MMCONFIG will be used.
1933 If you choose "Any", the kernel will try MMCONFIG, then the
1934 direct access method and falls back to the BIOS if that doesn't
1935 work. If unsure, go with the default, which is "Any".
1940 config PCI_GOMMCONFIG
1957 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1959 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1962 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1966 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1970 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1974 depends on PCI && XEN
1982 bool "Support mmconfig PCI config space access"
1983 depends on X86_64 && PCI && ACPI
1985 config PCI_CNB20LE_QUIRK
1986 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1988 depends on PCI && EXPERIMENTAL
1990 Read the PCI windows out of the CNB20LE host bridge. This allows
1991 PCI hotplug to work on systems with the CNB20LE chipset which do
1994 There's no public spec for this chipset, and this functionality
1995 is known to be incomplete.
1997 You should say N unless you know you need this.
1999 source "drivers/pci/pcie/Kconfig"
2001 source "drivers/pci/Kconfig"
2003 # x86_64 have no ISA slots, but can have ISA-style DMA.
2005 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2008 Enables ISA-style DMA support for devices requiring such controllers.
2016 Find out whether you have ISA slots on your motherboard. ISA is the
2017 name of a bus system, i.e. the way the CPU talks to the other stuff
2018 inside your box. Other bus systems are PCI, EISA, MicroChannel
2019 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2020 newer boards don't support it. If you have ISA, say Y, otherwise N.
2026 The Extended Industry Standard Architecture (EISA) bus was
2027 developed as an open alternative to the IBM MicroChannel bus.
2029 The EISA bus provided some of the features of the IBM MicroChannel
2030 bus while maintaining backward compatibility with cards made for
2031 the older ISA bus. The EISA bus saw limited use between 1988 and
2032 1995 when it was made obsolete by the PCI bus.
2034 Say Y here if you are building a kernel for an EISA-based machine.
2038 source "drivers/eisa/Kconfig"
2043 MicroChannel Architecture is found in some IBM PS/2 machines and
2044 laptops. It is a bus system similar to PCI or ISA. See
2045 <file:Documentation/mca.txt> (and especially the web page given
2046 there) before attempting to build an MCA bus kernel.
2048 source "drivers/mca/Kconfig"
2051 tristate "NatSemi SCx200 support"
2053 This provides basic support for National Semiconductor's
2054 (now AMD's) Geode processors. The driver probes for the
2055 PCI-IDs of several on-chip devices, so its a good dependency
2056 for other scx200_* drivers.
2058 If compiled as a module, the driver is named scx200.
2060 config SCx200HR_TIMER
2061 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2065 This driver provides a clocksource built upon the on-chip
2066 27MHz high-resolution timer. Its also a workaround for
2067 NSC Geode SC-1100's buggy TSC, which loses time when the
2068 processor goes idle (as is done by the scheduler). The
2069 other workaround is idle=poll boot option.
2072 bool "One Laptop Per Child support"
2078 Add support for detecting the unique features of the OLPC
2082 bool "OLPC XO-1 Power Management"
2083 depends on OLPC && MFD_CS5535 && PM_SLEEP
2086 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2089 bool "OLPC XO-1 Real Time Clock"
2090 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2092 Add support for the XO-1 real time clock, which can be used as a
2093 programmable wakeup source.
2096 bool "OLPC XO-1 SCI extras"
2097 depends on OLPC && OLPC_XO1_PM
2102 Add support for SCI-based features of the OLPC XO-1 laptop:
2103 - EC-driven system wakeups
2107 - AC adapter status updates
2108 - Battery status updates
2110 config OLPC_XO15_SCI
2111 bool "OLPC XO-1.5 SCI extras"
2112 depends on OLPC && ACPI
2115 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2116 - EC-driven system wakeups
2117 - AC adapter status updates
2118 - Battery status updates
2121 bool "PCEngines ALIX System Support (LED setup)"
2124 This option enables system support for the PCEngines ALIX.
2125 At present this just sets up LEDs for GPIO control on
2126 ALIX2/3/6 boards. However, other system specific setup should
2129 Note: You must still enable the drivers for GPIO and LED support
2130 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2132 Note: You have to set alix.force=1 for boards with Award BIOS.
2138 depends on CPU_SUP_AMD && PCI
2140 source "drivers/pcmcia/Kconfig"
2142 source "drivers/pci/hotplug/Kconfig"
2145 bool "RapidIO support"
2149 If you say Y here, the kernel will include drivers and
2150 infrastructure code to support RapidIO interconnect devices.
2152 source "drivers/rapidio/Kconfig"
2157 menu "Executable file formats / Emulations"
2159 source "fs/Kconfig.binfmt"
2161 config IA32_EMULATION
2162 bool "IA32 Emulation"
2164 select COMPAT_BINFMT_ELF
2166 Include code to run 32-bit programs under a 64-bit kernel. You should
2167 likely turn this on, unless you're 100% sure that you don't have any
2168 32-bit programs left.
2171 tristate "IA32 a.out support"
2172 depends on IA32_EMULATION
2174 Support old a.out binaries in the 32bit emulation.
2178 depends on IA32_EMULATION
2180 config COMPAT_FOR_U64_ALIGNMENT
2184 config SYSVIPC_COMPAT
2186 depends on COMPAT && SYSVIPC
2190 depends on COMPAT && KEYS
2196 config HAVE_ATOMIC_IOMAP
2200 config HAVE_TEXT_POKE_SMP
2202 select STOP_MACHINE if SMP
2204 source "net/Kconfig"
2206 source "drivers/Kconfig"
2208 source "drivers/firmware/Kconfig"
2212 source "arch/x86/Kconfig.debug"
2214 source "security/Kconfig"
2216 source "crypto/Kconfig"
2218 source "arch/x86/kvm/Kconfig"
2220 source "lib/Kconfig"