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_ARCH_KMEMCHECK
65 select HAVE_USER_RETURN_NOTIFIER
66 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
67 select HAVE_ARCH_JUMP_LABEL
68 select HAVE_TEXT_POKE_SMP
69 select HAVE_GENERIC_HARDIRQS
70 select HAVE_SPARSE_IRQ
72 select GENERIC_FIND_FIRST_BIT
73 select GENERIC_IRQ_PROBE
74 select GENERIC_PENDING_IRQ if SMP
75 select GENERIC_IRQ_SHOW
76 select GENERIC_CLOCKEVENTS_MIN_ADJUST
77 select IRQ_FORCED_THREADING
78 select USE_GENERIC_SMP_HELPERS if SMP
79 select HAVE_BPF_JIT if (X86_64 && NET)
81 select ARCH_HAVE_NMI_SAFE_CMPXCHG
84 config INSTRUCTION_DECODER
85 def_bool (KPROBES || PERF_EVENTS)
89 default "elf32-i386" if X86_32
90 default "elf64-x86-64" if X86_64
94 default "arch/x86/configs/i386_defconfig" if X86_32
95 default "arch/x86/configs/x86_64_defconfig" if X86_64
97 config GENERIC_CMOS_UPDATE
100 config CLOCKSOURCE_WATCHDOG
103 config GENERIC_CLOCKEVENTS
106 config ARCH_CLOCKSOURCE_DATA
110 config GENERIC_CLOCKEVENTS_BROADCAST
112 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
114 config LOCKDEP_SUPPORT
117 config STACKTRACE_SUPPORT
120 config HAVE_LATENCYTOP_SUPPORT
127 bool "DMA memory allocation support" if EXPERT
130 DMA memory allocation support allows devices with less than 32-bit
131 addressing to allocate within the first 16MB of address space.
132 Disable if no such devices will be used.
139 config NEED_DMA_MAP_STATE
140 def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG)
142 config NEED_SG_DMA_LENGTH
145 config GENERIC_ISA_DMA
151 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
153 config GENERIC_BUG_RELATIVE_POINTERS
156 config GENERIC_HWEIGHT
162 config ARCH_MAY_HAVE_PC_FDC
165 config RWSEM_GENERIC_SPINLOCK
168 config RWSEM_XCHGADD_ALGORITHM
171 config ARCH_HAS_CPU_IDLE_WAIT
174 config GENERIC_CALIBRATE_DELAY
177 config GENERIC_TIME_VSYSCALL
181 config ARCH_HAS_CPU_RELAX
184 config ARCH_HAS_DEFAULT_IDLE
187 config ARCH_HAS_CACHE_LINE_SIZE
190 config HAVE_SETUP_PER_CPU_AREA
193 config NEED_PER_CPU_EMBED_FIRST_CHUNK
196 config NEED_PER_CPU_PAGE_FIRST_CHUNK
199 config ARCH_HIBERNATION_POSSIBLE
202 config ARCH_SUSPEND_POSSIBLE
213 config ARCH_SUPPORTS_OPTIMIZED_INLINING
216 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
219 config HAVE_INTEL_TXT
221 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
225 depends on X86_32 && SMP
229 depends on X86_64 && SMP
235 config X86_32_LAZY_GS
237 depends on X86_32 && !CC_STACKPROTECTOR
239 config ARCH_HWEIGHT_CFLAGS
241 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
242 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
247 config ARCH_CPU_PROBE_RELEASE
249 depends on HOTPLUG_CPU
251 source "init/Kconfig"
252 source "kernel/Kconfig.freezer"
254 menu "Processor type and features"
256 source "kernel/time/Kconfig"
259 bool "Symmetric multi-processing support"
261 This enables support for systems with more than one CPU. If you have
262 a system with only one CPU, like most personal computers, say N. If
263 you have a system with more than one CPU, say Y.
265 If you say N here, the kernel will run on single and multiprocessor
266 machines, but will use only one CPU of a multiprocessor machine. If
267 you say Y here, the kernel will run on many, but not all,
268 singleprocessor machines. On a singleprocessor machine, the kernel
269 will run faster if you say N here.
271 Note that if you say Y here and choose architecture "586" or
272 "Pentium" under "Processor family", the kernel will not work on 486
273 architectures. Similarly, multiprocessor kernels for the "PPro"
274 architecture may not work on all Pentium based boards.
276 People using multiprocessor machines who say Y here should also say
277 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
278 Management" code will be disabled if you say Y here.
280 See also <file:Documentation/x86/i386/IO-APIC.txt>,
281 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
282 <http://www.tldp.org/docs.html#howto>.
284 If you don't know what to do here, say N.
287 bool "Support x2apic"
288 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
290 This enables x2apic support on CPUs that have this feature.
292 This allows 32-bit apic IDs (so it can support very large systems),
293 and accesses the local apic via MSRs not via mmio.
295 If you don't know what to do here, say N.
298 bool "Enable MPS table" if ACPI
300 depends on X86_LOCAL_APIC
302 For old smp systems that do not have proper acpi support. Newer systems
303 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
306 bool "Support for big SMP systems with more than 8 CPUs"
307 depends on X86_32 && SMP
309 This option is needed for the systems that have more than 8 CPUs
312 config X86_EXTENDED_PLATFORM
313 bool "Support for extended (non-PC) x86 platforms"
316 If you disable this option then the kernel will only support
317 standard PC platforms. (which covers the vast majority of
320 If you enable this option then you'll be able to select support
321 for the following (non-PC) 32 bit x86 platforms:
325 SGI 320/540 (Visual Workstation)
326 Summit/EXA (IBM x440)
327 Unisys ES7000 IA32 series
328 Moorestown MID devices
330 If you have one of these systems, or if you want to build a
331 generic distribution kernel, say Y here - otherwise say N.
335 config X86_EXTENDED_PLATFORM
336 bool "Support for extended (non-PC) x86 platforms"
339 If you disable this option then the kernel will only support
340 standard PC platforms. (which covers the vast majority of
343 If you enable this option then you'll be able to select support
344 for the following (non-PC) 64 bit x86 platforms:
349 If you have one of these systems, or if you want to build a
350 generic distribution kernel, say Y here - otherwise say N.
352 # This is an alphabetically sorted list of 64 bit extended platforms
353 # Please maintain the alphabetic order if and when there are additions
355 bool "Numascale NumaChip"
357 depends on X86_EXTENDED_PLATFORM
360 depends on X86_X2APIC
361 depends on !EDAC_AMD64
363 Adds support for Numascale NumaChip large-SMP systems. Needed to
364 enable more than ~168 cores.
365 If you don't have one of these, you should say N here.
369 select PARAVIRT_GUEST
371 depends on X86_64 && PCI
372 depends on X86_EXTENDED_PLATFORM
374 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
375 supposed to run on these EM64T-based machines. Only choose this option
376 if you have one of these machines.
379 bool "SGI Ultraviolet"
381 depends on X86_EXTENDED_PLATFORM
383 depends on X86_X2APIC
385 This option is needed in order to support SGI Ultraviolet systems.
386 If you don't have one of these, you should say N here.
388 # Following is an alphabetically sorted list of 32 bit extended platforms
389 # Please maintain the alphabetic order if and when there are additions
392 bool "CE4100 TV platform"
394 depends on PCI_GODIRECT
396 depends on X86_EXTENDED_PLATFORM
397 select X86_REBOOTFIXUPS
399 select OF_EARLY_FLATTREE
401 Select for the Intel CE media processor (CE4100) SOC.
402 This option compiles in support for the CE4100 SOC for settop
403 boxes and media devices.
405 config X86_WANT_INTEL_MID
406 bool "Intel MID platform support"
408 depends on X86_EXTENDED_PLATFORM
410 Select to build a kernel capable of supporting Intel MID platform
411 systems which do not have the PCI legacy interfaces (Moorestown,
412 Medfield). If you are building for a PC class system say N here.
414 if X86_WANT_INTEL_MID
420 bool "Moorestown MID platform"
423 depends on X86_IO_APIC
431 select X86_PLATFORM_DEVICES
433 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
434 Internet Device(MID) platform. Moorestown consists of two chips:
435 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
436 Unlike standard x86 PCs, Moorestown does not have many legacy devices
437 nor standard legacy replacement devices/features. e.g. Moorestown does
438 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
441 bool "Medfield MID platform"
444 depends on X86_IO_APIC
452 select X86_PLATFORM_DEVICES
454 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
455 Internet Device(MID) platform.
456 Unlike standard x86 PCs, Medfield does not have many legacy devices
457 nor standard legacy replacement devices/features. e.g. Medfield does
458 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
463 bool "RDC R-321x SoC"
465 depends on X86_EXTENDED_PLATFORM
467 select X86_REBOOTFIXUPS
469 This option is needed for RDC R-321x system-on-chip, also known
471 If you don't have one of these chips, you should say N here.
473 config X86_32_NON_STANDARD
474 bool "Support non-standard 32-bit SMP architectures"
475 depends on X86_32 && SMP
476 depends on X86_EXTENDED_PLATFORM
478 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
479 subarchitectures. It is intended for a generic binary kernel.
480 if you select them all, kernel will probe it one by one. and will
483 # Alphabetically sorted list of Non standard 32 bit platforms
486 bool "NUMAQ (IBM/Sequent)"
487 depends on X86_32_NON_STANDARD
492 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
493 NUMA multiquad box. This changes the way that processors are
494 bootstrapped, and uses Clustered Logical APIC addressing mode instead
495 of Flat Logical. You will need a new lynxer.elf file to flash your
496 firmware with - send email to <Martin.Bligh@us.ibm.com>.
498 config X86_SUPPORTS_MEMORY_FAILURE
500 # MCE code calls memory_failure():
502 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
503 depends on !X86_NUMAQ
504 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
505 depends on X86_64 || !SPARSEMEM
506 select ARCH_SUPPORTS_MEMORY_FAILURE
509 bool "SGI 320/540 (Visual Workstation)"
510 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
511 depends on X86_32_NON_STANDARD
513 The SGI Visual Workstation series is an IA32-based workstation
514 based on SGI systems chips with some legacy PC hardware attached.
516 Say Y here to create a kernel to run on the SGI 320 or 540.
518 A kernel compiled for the Visual Workstation will run on general
519 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
522 bool "Summit/EXA (IBM x440)"
523 depends on X86_32_NON_STANDARD
525 This option is needed for IBM systems that use the Summit/EXA chipset.
526 In particular, it is needed for the x440.
529 bool "Unisys ES7000 IA32 series"
530 depends on X86_32_NON_STANDARD && X86_BIGSMP
532 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
533 supposed to run on an IA32-based Unisys ES7000 system.
536 tristate "Eurobraille/Iris poweroff module"
539 The Iris machines from EuroBraille do not have APM or ACPI support
540 to shut themselves down properly. A special I/O sequence is
541 needed to do so, which is what this module does at
544 This is only for Iris machines from EuroBraille.
548 config SCHED_OMIT_FRAME_POINTER
550 prompt "Single-depth WCHAN output"
553 Calculate simpler /proc/<PID>/wchan values. If this option
554 is disabled then wchan values will recurse back to the
555 caller function. This provides more accurate wchan values,
556 at the expense of slightly more scheduling overhead.
558 If in doubt, say "Y".
560 menuconfig PARAVIRT_GUEST
561 bool "Paravirtualized guest support"
563 Say Y here to get to see options related to running Linux under
564 various hypervisors. This option alone does not add any kernel code.
566 If you say N, all options in this submenu will be skipped and disabled.
570 config PARAVIRT_TIME_ACCOUNTING
571 bool "Paravirtual steal time accounting"
575 Select this option to enable fine granularity task steal time
576 accounting. Time spent executing other tasks in parallel with
577 the current vCPU is discounted from the vCPU power. To account for
578 that, there can be a small performance impact.
580 If in doubt, say N here.
582 source "arch/x86/xen/Kconfig"
585 bool "KVM paravirtualized clock"
587 select PARAVIRT_CLOCK
589 Turning on this option will allow you to run a paravirtualized clock
590 when running over the KVM hypervisor. Instead of relying on a PIT
591 (or probably other) emulation by the underlying device model, the host
592 provides the guest with timing infrastructure such as time of day, and
596 bool "KVM Guest support"
599 This option enables various optimizations for running under the KVM
602 source "arch/x86/lguest/Kconfig"
605 bool "Enable paravirtualization code"
607 This changes the kernel so it can modify itself when it is run
608 under a hypervisor, potentially improving performance significantly
609 over full virtualization. However, when run without a hypervisor
610 the kernel is theoretically slower and slightly larger.
612 config PARAVIRT_SPINLOCKS
613 bool "Paravirtualization layer for spinlocks"
614 depends on PARAVIRT && SMP && EXPERIMENTAL
616 Paravirtualized spinlocks allow a pvops backend to replace the
617 spinlock implementation with something virtualization-friendly
618 (for example, block the virtual CPU rather than spinning).
620 Unfortunately the downside is an up to 5% performance hit on
621 native kernels, with various workloads.
623 If you are unsure how to answer this question, answer N.
625 config PARAVIRT_CLOCK
630 config PARAVIRT_DEBUG
631 bool "paravirt-ops debugging"
632 depends on PARAVIRT && DEBUG_KERNEL
634 Enable to debug paravirt_ops internals. Specifically, BUG if
635 a paravirt_op is missing when it is called.
643 This option adds a kernel parameter 'memtest', which allows memtest
645 memtest=0, mean disabled; -- default
646 memtest=1, mean do 1 test pattern;
648 memtest=4, mean do 4 test patterns.
649 If you are unsure how to answer this question, answer N.
651 config X86_SUMMIT_NUMA
653 depends on X86_32 && NUMA && X86_32_NON_STANDARD
655 config X86_CYCLONE_TIMER
657 depends on X86_SUMMIT
659 source "arch/x86/Kconfig.cpu"
663 prompt "HPET Timer Support" if X86_32
665 Use the IA-PC HPET (High Precision Event Timer) to manage
666 time in preference to the PIT and RTC, if a HPET is
668 HPET is the next generation timer replacing legacy 8254s.
669 The HPET provides a stable time base on SMP
670 systems, unlike the TSC, but it is more expensive to access,
671 as it is off-chip. You can find the HPET spec at
672 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
674 You can safely choose Y here. However, HPET will only be
675 activated if the platform and the BIOS support this feature.
676 Otherwise the 8254 will be used for timing services.
678 Choose N to continue using the legacy 8254 timer.
680 config HPET_EMULATE_RTC
682 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
685 def_bool y if X86_INTEL_MID
686 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
688 depends on X86_INTEL_MID && SFI
690 APB timer is the replacement for 8254, HPET on X86 MID platforms.
691 The APBT provides a stable time base on SMP
692 systems, unlike the TSC, but it is more expensive to access,
693 as it is off-chip. APB timers are always running regardless of CPU
694 C states, they are used as per CPU clockevent device when possible.
696 # Mark as expert because too many people got it wrong.
697 # The code disables itself when not needed.
700 bool "Enable DMI scanning" if EXPERT
702 Enabled scanning of DMI to identify machine quirks. Say Y
703 here unless you have verified that your setup is not
704 affected by entries in the DMI blacklist. Required by PNP
708 bool "GART IOMMU support" if EXPERT
711 depends on X86_64 && PCI && AMD_NB
713 Support for full DMA access of devices with 32bit memory access only
714 on systems with more than 3GB. This is usually needed for USB,
715 sound, many IDE/SATA chipsets and some other devices.
716 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
717 based hardware IOMMU and a software bounce buffer based IOMMU used
718 on Intel systems and as fallback.
719 The code is only active when needed (enough memory and limited
720 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
724 bool "IBM Calgary IOMMU support"
726 depends on X86_64 && PCI && EXPERIMENTAL
728 Support for hardware IOMMUs in IBM's xSeries x366 and x460
729 systems. Needed to run systems with more than 3GB of memory
730 properly with 32-bit PCI devices that do not support DAC
731 (Double Address Cycle). Calgary also supports bus level
732 isolation, where all DMAs pass through the IOMMU. This
733 prevents them from going anywhere except their intended
734 destination. This catches hard-to-find kernel bugs and
735 mis-behaving drivers and devices that do not use the DMA-API
736 properly to set up their DMA buffers. The IOMMU can be
737 turned off at boot time with the iommu=off parameter.
738 Normally the kernel will make the right choice by itself.
741 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
743 prompt "Should Calgary be enabled by default?"
744 depends on CALGARY_IOMMU
746 Should Calgary be enabled by default? if you choose 'y', Calgary
747 will be used (if it exists). If you choose 'n', Calgary will not be
748 used even if it exists. If you choose 'n' and would like to use
749 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
752 # need this always selected by IOMMU for the VIA workaround
756 Support for software bounce buffers used on x86-64 systems
757 which don't have a hardware IOMMU (e.g. the current generation
758 of Intel's x86-64 CPUs). Using this PCI devices which can only
759 access 32-bits of memory can be used on systems with more than
760 3 GB of memory. If unsure, say Y.
763 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
766 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
767 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
768 select CPUMASK_OFFSTACK
770 Enable maximum number of CPUS and NUMA Nodes for this architecture.
774 int "Maximum number of CPUs" if SMP && !MAXSMP
775 range 2 8 if SMP && X86_32 && !X86_BIGSMP
776 range 2 512 if SMP && !MAXSMP
778 default "4096" if MAXSMP
779 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
782 This allows you to specify the maximum number of CPUs which this
783 kernel will support. The maximum supported value is 512 and the
784 minimum value which makes sense is 2.
786 This is purely to save memory - each supported CPU adds
787 approximately eight kilobytes to the kernel image.
790 bool "SMT (Hyperthreading) scheduler support"
793 SMT scheduler support improves the CPU scheduler's decision making
794 when dealing with Intel Pentium 4 chips with HyperThreading at a
795 cost of slightly increased overhead in some places. If unsure say
800 prompt "Multi-core scheduler support"
803 Multi-core scheduler support improves the CPU scheduler's decision
804 making when dealing with multi-core CPU chips at a cost of slightly
805 increased overhead in some places. If unsure say N here.
807 config IRQ_TIME_ACCOUNTING
808 bool "Fine granularity task level IRQ time accounting"
811 Select this option to enable fine granularity task irq time
812 accounting. This is done by reading a timestamp on each
813 transitions between softirq and hardirq state, so there can be a
814 small performance impact.
816 If in doubt, say N here.
818 source "kernel/Kconfig.preempt"
821 bool "Local APIC support on uniprocessors"
822 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
824 A local APIC (Advanced Programmable Interrupt Controller) is an
825 integrated interrupt controller in the CPU. If you have a single-CPU
826 system which has a processor with a local APIC, you can say Y here to
827 enable and use it. If you say Y here even though your machine doesn't
828 have a local APIC, then the kernel will still run with no slowdown at
829 all. The local APIC supports CPU-generated self-interrupts (timer,
830 performance counters), and the NMI watchdog which detects hard
834 bool "IO-APIC support on uniprocessors"
835 depends on X86_UP_APIC
837 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
838 SMP-capable replacement for PC-style interrupt controllers. Most
839 SMP systems and many recent uniprocessor systems have one.
841 If you have a single-CPU system with an IO-APIC, you can say Y here
842 to use it. If you say Y here even though your machine doesn't have
843 an IO-APIC, then the kernel will still run with no slowdown at all.
845 config X86_LOCAL_APIC
847 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
851 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
853 config X86_VISWS_APIC
855 depends on X86_32 && X86_VISWS
857 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
858 bool "Reroute for broken boot IRQs"
859 depends on X86_IO_APIC
861 This option enables a workaround that fixes a source of
862 spurious interrupts. This is recommended when threaded
863 interrupt handling is used on systems where the generation of
864 superfluous "boot interrupts" cannot be disabled.
866 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
867 entry in the chipset's IO-APIC is masked (as, e.g. the RT
868 kernel does during interrupt handling). On chipsets where this
869 boot IRQ generation cannot be disabled, this workaround keeps
870 the original IRQ line masked so that only the equivalent "boot
871 IRQ" is delivered to the CPUs. The workaround also tells the
872 kernel to set up the IRQ handler on the boot IRQ line. In this
873 way only one interrupt is delivered to the kernel. Otherwise
874 the spurious second interrupt may cause the kernel to bring
875 down (vital) interrupt lines.
877 Only affects "broken" chipsets. Interrupt sharing may be
878 increased on these systems.
881 bool "Machine Check / overheating reporting"
883 Machine Check support allows the processor to notify the
884 kernel if it detects a problem (e.g. overheating, data corruption).
885 The action the kernel takes depends on the severity of the problem,
886 ranging from warning messages to halting the machine.
890 prompt "Intel MCE features"
891 depends on X86_MCE && X86_LOCAL_APIC
893 Additional support for intel specific MCE features such as
898 prompt "AMD MCE features"
899 depends on X86_MCE && X86_LOCAL_APIC
901 Additional support for AMD specific MCE features such as
902 the DRAM Error Threshold.
904 config X86_ANCIENT_MCE
905 bool "Support for old Pentium 5 / WinChip machine checks"
906 depends on X86_32 && X86_MCE
908 Include support for machine check handling on old Pentium 5 or WinChip
909 systems. These typically need to be enabled explicitely on the command
912 config X86_MCE_THRESHOLD
913 depends on X86_MCE_AMD || X86_MCE_INTEL
916 config X86_MCE_INJECT
918 tristate "Machine check injector support"
920 Provide support for injecting machine checks for testing purposes.
921 If you don't know what a machine check is and you don't do kernel
922 QA it is safe to say n.
924 config X86_THERMAL_VECTOR
926 depends on X86_MCE_INTEL
929 bool "Enable VM86 support" if EXPERT
933 This option is required by programs like DOSEMU to run 16-bit legacy
934 code on X86 processors. It also may be needed by software like
935 XFree86 to initialize some video cards via BIOS. Disabling this
936 option saves about 6k.
939 tristate "Toshiba Laptop support"
942 This adds a driver to safely access the System Management Mode of
943 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
944 not work on models with a Phoenix BIOS. The System Management Mode
945 is used to set the BIOS and power saving options on Toshiba portables.
947 For information on utilities to make use of this driver see the
948 Toshiba Linux utilities web site at:
949 <http://www.buzzard.org.uk/toshiba/>.
951 Say Y if you intend to run this kernel on a Toshiba portable.
955 tristate "Dell laptop support"
958 This adds a driver to safely access the System Management Mode
959 of the CPU on the Dell Inspiron 8000. The System Management Mode
960 is used to read cpu temperature and cooling fan status and to
961 control the fans on the I8K portables.
963 This driver has been tested only on the Inspiron 8000 but it may
964 also work with other Dell laptops. You can force loading on other
965 models by passing the parameter `force=1' to the module. Use at
968 For information on utilities to make use of this driver see the
969 I8K Linux utilities web site at:
970 <http://people.debian.org/~dz/i8k/>
972 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
975 config X86_REBOOTFIXUPS
976 bool "Enable X86 board specific fixups for reboot"
979 This enables chipset and/or board specific fixups to be done
980 in order to get reboot to work correctly. This is only needed on
981 some combinations of hardware and BIOS. The symptom, for which
982 this config is intended, is when reboot ends with a stalled/hung
985 Currently, the only fixup is for the Geode machines using
986 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
988 Say Y if you want to enable the fixup. Currently, it's safe to
989 enable this option even if you don't need it.
993 tristate "/dev/cpu/microcode - microcode support"
996 If you say Y here, you will be able to update the microcode on
997 certain Intel and AMD processors. The Intel support is for the
998 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
999 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
1000 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
1001 You will obviously need the actual microcode binary data itself
1002 which is not shipped with the Linux kernel.
1004 This option selects the general module only, you need to select
1005 at least one vendor specific module as well.
1007 To compile this driver as a module, choose M here: the
1008 module will be called microcode.
1010 config MICROCODE_INTEL
1011 bool "Intel microcode patch loading support"
1012 depends on MICROCODE
1016 This options enables microcode patch loading support for Intel
1019 For latest news and information on obtaining all the required
1020 Intel ingredients for this driver, check:
1021 <http://www.urbanmyth.org/microcode/>.
1023 config MICROCODE_AMD
1024 bool "AMD microcode patch loading support"
1025 depends on MICROCODE
1028 If you select this option, microcode patch loading support for AMD
1029 processors will be enabled.
1031 config MICROCODE_OLD_INTERFACE
1033 depends on MICROCODE
1036 tristate "/dev/cpu/*/msr - Model-specific register support"
1038 This device gives privileged processes access to the x86
1039 Model-Specific Registers (MSRs). It is a character device with
1040 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1041 MSR accesses are directed to a specific CPU on multi-processor
1045 tristate "/dev/cpu/*/cpuid - CPU information support"
1047 This device gives processes access to the x86 CPUID instruction to
1048 be executed on a specific processor. It is a character device
1049 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1053 prompt "High Memory Support"
1054 default HIGHMEM64G if X86_NUMAQ
1060 depends on !X86_NUMAQ
1062 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1063 However, the address space of 32-bit x86 processors is only 4
1064 Gigabytes large. That means that, if you have a large amount of
1065 physical memory, not all of it can be "permanently mapped" by the
1066 kernel. The physical memory that's not permanently mapped is called
1069 If you are compiling a kernel which will never run on a machine with
1070 more than 1 Gigabyte total physical RAM, answer "off" here (default
1071 choice and suitable for most users). This will result in a "3GB/1GB"
1072 split: 3GB are mapped so that each process sees a 3GB virtual memory
1073 space and the remaining part of the 4GB virtual memory space is used
1074 by the kernel to permanently map as much physical memory as
1077 If the machine has between 1 and 4 Gigabytes physical RAM, then
1080 If more than 4 Gigabytes is used then answer "64GB" here. This
1081 selection turns Intel PAE (Physical Address Extension) mode on.
1082 PAE implements 3-level paging on IA32 processors. PAE is fully
1083 supported by Linux, PAE mode is implemented on all recent Intel
1084 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1085 then the kernel will not boot on CPUs that don't support PAE!
1087 The actual amount of total physical memory will either be
1088 auto detected or can be forced by using a kernel command line option
1089 such as "mem=256M". (Try "man bootparam" or see the documentation of
1090 your boot loader (lilo or loadlin) about how to pass options to the
1091 kernel at boot time.)
1093 If unsure, say "off".
1097 depends on !X86_NUMAQ
1099 Select this if you have a 32-bit processor and between 1 and 4
1100 gigabytes of physical RAM.
1104 depends on !M386 && !M486
1107 Select this if you have a 32-bit processor and more than 4
1108 gigabytes of physical RAM.
1113 depends on EXPERIMENTAL
1114 prompt "Memory split" if EXPERT
1118 Select the desired split between kernel and user memory.
1120 If the address range available to the kernel is less than the
1121 physical memory installed, the remaining memory will be available
1122 as "high memory". Accessing high memory is a little more costly
1123 than low memory, as it needs to be mapped into the kernel first.
1124 Note that increasing the kernel address space limits the range
1125 available to user programs, making the address space there
1126 tighter. Selecting anything other than the default 3G/1G split
1127 will also likely make your kernel incompatible with binary-only
1130 If you are not absolutely sure what you are doing, leave this
1134 bool "3G/1G user/kernel split"
1135 config VMSPLIT_3G_OPT
1137 bool "3G/1G user/kernel split (for full 1G low memory)"
1139 bool "2G/2G user/kernel split"
1140 config VMSPLIT_2G_OPT
1142 bool "2G/2G user/kernel split (for full 2G low memory)"
1144 bool "1G/3G user/kernel split"
1149 default 0xB0000000 if VMSPLIT_3G_OPT
1150 default 0x80000000 if VMSPLIT_2G
1151 default 0x78000000 if VMSPLIT_2G_OPT
1152 default 0x40000000 if VMSPLIT_1G
1158 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1161 bool "PAE (Physical Address Extension) Support"
1162 depends on X86_32 && !HIGHMEM4G
1164 PAE is required for NX support, and furthermore enables
1165 larger swapspace support for non-overcommit purposes. It
1166 has the cost of more pagetable lookup overhead, and also
1167 consumes more pagetable space per process.
1169 config ARCH_PHYS_ADDR_T_64BIT
1170 def_bool X86_64 || X86_PAE
1172 config ARCH_DMA_ADDR_T_64BIT
1173 def_bool X86_64 || HIGHMEM64G
1175 config DIRECT_GBPAGES
1176 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1180 Allow the kernel linear mapping to use 1GB pages on CPUs that
1181 support it. This can improve the kernel's performance a tiny bit by
1182 reducing TLB pressure. If in doubt, say "Y".
1184 # Common NUMA Features
1186 bool "Numa Memory Allocation and Scheduler Support"
1188 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1189 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1191 Enable NUMA (Non Uniform Memory Access) support.
1193 The kernel will try to allocate memory used by a CPU on the
1194 local memory controller of the CPU and add some more
1195 NUMA awareness to the kernel.
1197 For 64-bit this is recommended if the system is Intel Core i7
1198 (or later), AMD Opteron, or EM64T NUMA.
1200 For 32-bit this is only needed on (rare) 32-bit-only platforms
1201 that support NUMA topologies, such as NUMAQ / Summit, or if you
1202 boot a 32-bit kernel on a 64-bit NUMA platform.
1204 Otherwise, you should say N.
1206 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1207 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1211 prompt "Old style AMD Opteron NUMA detection"
1212 depends on X86_64 && NUMA && PCI
1214 Enable AMD NUMA node topology detection. You should say Y here if
1215 you have a multi processor AMD system. This uses an old method to
1216 read the NUMA configuration directly from the builtin Northbridge
1217 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1218 which also takes priority if both are compiled in.
1220 config X86_64_ACPI_NUMA
1222 prompt "ACPI NUMA detection"
1223 depends on X86_64 && NUMA && ACPI && PCI
1226 Enable ACPI SRAT based node topology detection.
1228 # Some NUMA nodes have memory ranges that span
1229 # other nodes. Even though a pfn is valid and
1230 # between a node's start and end pfns, it may not
1231 # reside on that node. See memmap_init_zone()
1233 config NODES_SPAN_OTHER_NODES
1235 depends on X86_64_ACPI_NUMA
1238 bool "NUMA emulation"
1241 Enable NUMA emulation. A flat machine will be split
1242 into virtual nodes when booted with "numa=fake=N", where N is the
1243 number of nodes. This is only useful for debugging.
1246 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1248 default "10" if MAXSMP
1249 default "6" if X86_64
1250 default "4" if X86_NUMAQ
1252 depends on NEED_MULTIPLE_NODES
1254 Specify the maximum number of NUMA Nodes available on the target
1255 system. Increases memory reserved to accommodate various tables.
1257 config HAVE_ARCH_BOOTMEM
1259 depends on X86_32 && NUMA
1261 config HAVE_ARCH_ALLOC_REMAP
1263 depends on X86_32 && NUMA
1265 config ARCH_HAVE_MEMORY_PRESENT
1267 depends on X86_32 && DISCONTIGMEM
1269 config NEED_NODE_MEMMAP_SIZE
1271 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1273 config ARCH_FLATMEM_ENABLE
1275 depends on X86_32 && !NUMA
1277 config ARCH_DISCONTIGMEM_ENABLE
1279 depends on NUMA && X86_32
1281 config ARCH_DISCONTIGMEM_DEFAULT
1283 depends on NUMA && X86_32
1285 config ARCH_SPARSEMEM_ENABLE
1287 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1288 select SPARSEMEM_STATIC if X86_32
1289 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1291 config ARCH_SPARSEMEM_DEFAULT
1295 config ARCH_SELECT_MEMORY_MODEL
1297 depends on ARCH_SPARSEMEM_ENABLE
1299 config ARCH_MEMORY_PROBE
1301 depends on MEMORY_HOTPLUG
1303 config ARCH_PROC_KCORE_TEXT
1305 depends on X86_64 && PROC_KCORE
1307 config ILLEGAL_POINTER_VALUE
1310 default 0xdead000000000000 if X86_64
1315 bool "Allocate 3rd-level pagetables from highmem"
1318 The VM uses one page table entry for each page of physical memory.
1319 For systems with a lot of RAM, this can be wasteful of precious
1320 low memory. Setting this option will put user-space page table
1321 entries in high memory.
1323 config X86_CHECK_BIOS_CORRUPTION
1324 bool "Check for low memory corruption"
1326 Periodically check for memory corruption in low memory, which
1327 is suspected to be caused by BIOS. Even when enabled in the
1328 configuration, it is disabled at runtime. Enable it by
1329 setting "memory_corruption_check=1" on the kernel command
1330 line. By default it scans the low 64k of memory every 60
1331 seconds; see the memory_corruption_check_size and
1332 memory_corruption_check_period parameters in
1333 Documentation/kernel-parameters.txt to adjust this.
1335 When enabled with the default parameters, this option has
1336 almost no overhead, as it reserves a relatively small amount
1337 of memory and scans it infrequently. It both detects corruption
1338 and prevents it from affecting the running system.
1340 It is, however, intended as a diagnostic tool; if repeatable
1341 BIOS-originated corruption always affects the same memory,
1342 you can use memmap= to prevent the kernel from using that
1345 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1346 bool "Set the default setting of memory_corruption_check"
1347 depends on X86_CHECK_BIOS_CORRUPTION
1350 Set whether the default state of memory_corruption_check is
1353 config X86_RESERVE_LOW
1354 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1358 Specify the amount of low memory to reserve for the BIOS.
1360 The first page contains BIOS data structures that the kernel
1361 must not use, so that page must always be reserved.
1363 By default we reserve the first 64K of physical RAM, as a
1364 number of BIOSes are known to corrupt that memory range
1365 during events such as suspend/resume or monitor cable
1366 insertion, so it must not be used by the kernel.
1368 You can set this to 4 if you are absolutely sure that you
1369 trust the BIOS to get all its memory reservations and usages
1370 right. If you know your BIOS have problems beyond the
1371 default 64K area, you can set this to 640 to avoid using the
1372 entire low memory range.
1374 If you have doubts about the BIOS (e.g. suspend/resume does
1375 not work or there's kernel crashes after certain hardware
1376 hotplug events) then you might want to enable
1377 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1378 typical corruption patterns.
1380 Leave this to the default value of 64 if you are unsure.
1382 config MATH_EMULATION
1384 prompt "Math emulation" if X86_32
1386 Linux can emulate a math coprocessor (used for floating point
1387 operations) if you don't have one. 486DX and Pentium processors have
1388 a math coprocessor built in, 486SX and 386 do not, unless you added
1389 a 487DX or 387, respectively. (The messages during boot time can
1390 give you some hints here ["man dmesg"].) Everyone needs either a
1391 coprocessor or this emulation.
1393 If you don't have a math coprocessor, you need to say Y here; if you
1394 say Y here even though you have a coprocessor, the coprocessor will
1395 be used nevertheless. (This behavior can be changed with the kernel
1396 command line option "no387", which comes handy if your coprocessor
1397 is broken. Try "man bootparam" or see the documentation of your boot
1398 loader (lilo or loadlin) about how to pass options to the kernel at
1399 boot time.) This means that it is a good idea to say Y here if you
1400 intend to use this kernel on different machines.
1402 More information about the internals of the Linux math coprocessor
1403 emulation can be found in <file:arch/x86/math-emu/README>.
1405 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1406 kernel, it won't hurt.
1410 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1412 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1413 the Memory Type Range Registers (MTRRs) may be used to control
1414 processor access to memory ranges. This is most useful if you have
1415 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1416 allows bus write transfers to be combined into a larger transfer
1417 before bursting over the PCI/AGP bus. This can increase performance
1418 of image write operations 2.5 times or more. Saying Y here creates a
1419 /proc/mtrr file which may be used to manipulate your processor's
1420 MTRRs. Typically the X server should use this.
1422 This code has a reasonably generic interface so that similar
1423 control registers on other processors can be easily supported
1426 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1427 Registers (ARRs) which provide a similar functionality to MTRRs. For
1428 these, the ARRs are used to emulate the MTRRs.
1429 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1430 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1431 write-combining. All of these processors are supported by this code
1432 and it makes sense to say Y here if you have one of them.
1434 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1435 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1436 can lead to all sorts of problems, so it's good to say Y here.
1438 You can safely say Y even if your machine doesn't have MTRRs, you'll
1439 just add about 9 KB to your kernel.
1441 See <file:Documentation/x86/mtrr.txt> for more information.
1443 config MTRR_SANITIZER
1445 prompt "MTRR cleanup support"
1448 Convert MTRR layout from continuous to discrete, so X drivers can
1449 add writeback entries.
1451 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1452 The largest mtrr entry size for a continuous block can be set with
1457 config MTRR_SANITIZER_ENABLE_DEFAULT
1458 int "MTRR cleanup enable value (0-1)"
1461 depends on MTRR_SANITIZER
1463 Enable mtrr cleanup default value
1465 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1466 int "MTRR cleanup spare reg num (0-7)"
1469 depends on MTRR_SANITIZER
1471 mtrr cleanup spare entries default, it can be changed via
1472 mtrr_spare_reg_nr=N on the kernel command line.
1476 prompt "x86 PAT support" if EXPERT
1479 Use PAT attributes to setup page level cache control.
1481 PATs are the modern equivalents of MTRRs and are much more
1482 flexible than MTRRs.
1484 Say N here if you see bootup problems (boot crash, boot hang,
1485 spontaneous reboots) or a non-working video driver.
1489 config ARCH_USES_PG_UNCACHED
1495 prompt "x86 architectural random number generator" if EXPERT
1497 Enable the x86 architectural RDRAND instruction
1498 (Intel Bull Mountain technology) to generate random numbers.
1499 If supported, this is a high bandwidth, cryptographically
1500 secure hardware random number generator.
1503 bool "EFI runtime service support"
1506 This enables the kernel to use EFI runtime services that are
1507 available (such as the EFI variable services).
1509 This option is only useful on systems that have EFI firmware.
1510 In addition, you should use the latest ELILO loader available
1511 at <http://elilo.sourceforge.net> in order to take advantage
1512 of EFI runtime services. However, even with this option, the
1513 resultant kernel should continue to boot on existing non-EFI
1517 bool "EFI stub support"
1520 This kernel feature allows a bzImage to be loaded directly
1521 by EFI firmware without the use of a bootloader.
1525 prompt "Enable seccomp to safely compute untrusted bytecode"
1527 This kernel feature is useful for number crunching applications
1528 that may need to compute untrusted bytecode during their
1529 execution. By using pipes or other transports made available to
1530 the process as file descriptors supporting the read/write
1531 syscalls, it's possible to isolate those applications in
1532 their own address space using seccomp. Once seccomp is
1533 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1534 and the task is only allowed to execute a few safe syscalls
1535 defined by each seccomp mode.
1537 If unsure, say Y. Only embedded should say N here.
1539 config CC_STACKPROTECTOR
1540 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1542 This option turns on the -fstack-protector GCC feature. This
1543 feature puts, at the beginning of functions, a canary value on
1544 the stack just before the return address, and validates
1545 the value just before actually returning. Stack based buffer
1546 overflows (that need to overwrite this return address) now also
1547 overwrite the canary, which gets detected and the attack is then
1548 neutralized via a kernel panic.
1550 This feature requires gcc version 4.2 or above, or a distribution
1551 gcc with the feature backported. Older versions are automatically
1552 detected and for those versions, this configuration option is
1553 ignored. (and a warning is printed during bootup)
1555 source kernel/Kconfig.hz
1558 bool "kexec system call"
1560 kexec is a system call that implements the ability to shutdown your
1561 current kernel, and to start another kernel. It is like a reboot
1562 but it is independent of the system firmware. And like a reboot
1563 you can start any kernel with it, not just Linux.
1565 The name comes from the similarity to the exec system call.
1567 It is an ongoing process to be certain the hardware in a machine
1568 is properly shutdown, so do not be surprised if this code does not
1569 initially work for you. It may help to enable device hotplugging
1570 support. As of this writing the exact hardware interface is
1571 strongly in flux, so no good recommendation can be made.
1574 bool "kernel crash dumps"
1575 depends on X86_64 || (X86_32 && HIGHMEM)
1577 Generate crash dump after being started by kexec.
1578 This should be normally only set in special crash dump kernels
1579 which are loaded in the main kernel with kexec-tools into
1580 a specially reserved region and then later executed after
1581 a crash by kdump/kexec. The crash dump kernel must be compiled
1582 to a memory address not used by the main kernel or BIOS using
1583 PHYSICAL_START, or it must be built as a relocatable image
1584 (CONFIG_RELOCATABLE=y).
1585 For more details see Documentation/kdump/kdump.txt
1588 bool "kexec jump (EXPERIMENTAL)"
1589 depends on EXPERIMENTAL
1590 depends on KEXEC && HIBERNATION
1592 Jump between original kernel and kexeced kernel and invoke
1593 code in physical address mode via KEXEC
1595 config PHYSICAL_START
1596 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1599 This gives the physical address where the kernel is loaded.
1601 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1602 bzImage will decompress itself to above physical address and
1603 run from there. Otherwise, bzImage will run from the address where
1604 it has been loaded by the boot loader and will ignore above physical
1607 In normal kdump cases one does not have to set/change this option
1608 as now bzImage can be compiled as a completely relocatable image
1609 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1610 address. This option is mainly useful for the folks who don't want
1611 to use a bzImage for capturing the crash dump and want to use a
1612 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1613 to be specifically compiled to run from a specific memory area
1614 (normally a reserved region) and this option comes handy.
1616 So if you are using bzImage for capturing the crash dump,
1617 leave the value here unchanged to 0x1000000 and set
1618 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1619 for capturing the crash dump change this value to start of
1620 the reserved region. In other words, it can be set based on
1621 the "X" value as specified in the "crashkernel=YM@XM"
1622 command line boot parameter passed to the panic-ed
1623 kernel. Please take a look at Documentation/kdump/kdump.txt
1624 for more details about crash dumps.
1626 Usage of bzImage for capturing the crash dump is recommended as
1627 one does not have to build two kernels. Same kernel can be used
1628 as production kernel and capture kernel. Above option should have
1629 gone away after relocatable bzImage support is introduced. But it
1630 is present because there are users out there who continue to use
1631 vmlinux for dump capture. This option should go away down the
1634 Don't change this unless you know what you are doing.
1637 bool "Build a relocatable kernel"
1640 This builds a kernel image that retains relocation information
1641 so it can be loaded someplace besides the default 1MB.
1642 The relocations tend to make the kernel binary about 10% larger,
1643 but are discarded at runtime.
1645 One use is for the kexec on panic case where the recovery kernel
1646 must live at a different physical address than the primary
1649 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1650 it has been loaded at and the compile time physical address
1651 (CONFIG_PHYSICAL_START) is ignored.
1653 # Relocation on x86-32 needs some additional build support
1654 config X86_NEED_RELOCS
1656 depends on X86_32 && RELOCATABLE
1658 config PHYSICAL_ALIGN
1659 hex "Alignment value to which kernel should be aligned" if X86_32
1661 range 0x2000 0x1000000
1663 This value puts the alignment restrictions on physical address
1664 where kernel is loaded and run from. Kernel is compiled for an
1665 address which meets above alignment restriction.
1667 If bootloader loads the kernel at a non-aligned address and
1668 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1669 address aligned to above value and run from there.
1671 If bootloader loads the kernel at a non-aligned address and
1672 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1673 load address and decompress itself to the address it has been
1674 compiled for and run from there. The address for which kernel is
1675 compiled already meets above alignment restrictions. Hence the
1676 end result is that kernel runs from a physical address meeting
1677 above alignment restrictions.
1679 Don't change this unless you know what you are doing.
1682 bool "Support for hot-pluggable CPUs"
1683 depends on SMP && HOTPLUG
1685 Say Y here to allow turning CPUs off and on. CPUs can be
1686 controlled through /sys/devices/system/cpu.
1687 ( Note: power management support will enable this option
1688 automatically on SMP systems. )
1689 Say N if you want to disable CPU hotplug.
1693 prompt "Compat VDSO support"
1694 depends on X86_32 || IA32_EMULATION
1696 Map the 32-bit VDSO to the predictable old-style address too.
1698 Say N here if you are running a sufficiently recent glibc
1699 version (2.3.3 or later), to remove the high-mapped
1700 VDSO mapping and to exclusively use the randomized VDSO.
1705 bool "Built-in kernel command line"
1707 Allow for specifying boot arguments to the kernel at
1708 build time. On some systems (e.g. embedded ones), it is
1709 necessary or convenient to provide some or all of the
1710 kernel boot arguments with the kernel itself (that is,
1711 to not rely on the boot loader to provide them.)
1713 To compile command line arguments into the kernel,
1714 set this option to 'Y', then fill in the
1715 the boot arguments in CONFIG_CMDLINE.
1717 Systems with fully functional boot loaders (i.e. non-embedded)
1718 should leave this option set to 'N'.
1721 string "Built-in kernel command string"
1722 depends on CMDLINE_BOOL
1725 Enter arguments here that should be compiled into the kernel
1726 image and used at boot time. If the boot loader provides a
1727 command line at boot time, it is appended to this string to
1728 form the full kernel command line, when the system boots.
1730 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1731 change this behavior.
1733 In most cases, the command line (whether built-in or provided
1734 by the boot loader) should specify the device for the root
1737 config CMDLINE_OVERRIDE
1738 bool "Built-in command line overrides boot loader arguments"
1739 depends on CMDLINE_BOOL
1741 Set this option to 'Y' to have the kernel ignore the boot loader
1742 command line, and use ONLY the built-in command line.
1744 This is used to work around broken boot loaders. This should
1745 be set to 'N' under normal conditions.
1749 config ARCH_ENABLE_MEMORY_HOTPLUG
1751 depends on X86_64 || (X86_32 && HIGHMEM)
1753 config ARCH_ENABLE_MEMORY_HOTREMOVE
1755 depends on MEMORY_HOTPLUG
1757 config USE_PERCPU_NUMA_NODE_ID
1761 menu "Power management and ACPI options"
1763 config ARCH_HIBERNATION_HEADER
1765 depends on X86_64 && HIBERNATION
1767 source "kernel/power/Kconfig"
1769 source "drivers/acpi/Kconfig"
1771 source "drivers/sfi/Kconfig"
1778 tristate "APM (Advanced Power Management) BIOS support"
1779 depends on X86_32 && PM_SLEEP
1781 APM is a BIOS specification for saving power using several different
1782 techniques. This is mostly useful for battery powered laptops with
1783 APM compliant BIOSes. If you say Y here, the system time will be
1784 reset after a RESUME operation, the /proc/apm device will provide
1785 battery status information, and user-space programs will receive
1786 notification of APM "events" (e.g. battery status change).
1788 If you select "Y" here, you can disable actual use of the APM
1789 BIOS by passing the "apm=off" option to the kernel at boot time.
1791 Note that the APM support is almost completely disabled for
1792 machines with more than one CPU.
1794 In order to use APM, you will need supporting software. For location
1795 and more information, read <file:Documentation/power/apm-acpi.txt>
1796 and the Battery Powered Linux mini-HOWTO, available from
1797 <http://www.tldp.org/docs.html#howto>.
1799 This driver does not spin down disk drives (see the hdparm(8)
1800 manpage ("man 8 hdparm") for that), and it doesn't turn off
1801 VESA-compliant "green" monitors.
1803 This driver does not support the TI 4000M TravelMate and the ACER
1804 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1805 desktop machines also don't have compliant BIOSes, and this driver
1806 may cause those machines to panic during the boot phase.
1808 Generally, if you don't have a battery in your machine, there isn't
1809 much point in using this driver and you should say N. If you get
1810 random kernel OOPSes or reboots that don't seem to be related to
1811 anything, try disabling/enabling this option (or disabling/enabling
1814 Some other things you should try when experiencing seemingly random,
1817 1) make sure that you have enough swap space and that it is
1819 2) pass the "no-hlt" option to the kernel
1820 3) switch on floating point emulation in the kernel and pass
1821 the "no387" option to the kernel
1822 4) pass the "floppy=nodma" option to the kernel
1823 5) pass the "mem=4M" option to the kernel (thereby disabling
1824 all but the first 4 MB of RAM)
1825 6) make sure that the CPU is not over clocked.
1826 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1827 8) disable the cache from your BIOS settings
1828 9) install a fan for the video card or exchange video RAM
1829 10) install a better fan for the CPU
1830 11) exchange RAM chips
1831 12) exchange the motherboard.
1833 To compile this driver as a module, choose M here: the
1834 module will be called apm.
1838 config APM_IGNORE_USER_SUSPEND
1839 bool "Ignore USER SUSPEND"
1841 This option will ignore USER SUSPEND requests. On machines with a
1842 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1843 series notebooks, it is necessary to say Y because of a BIOS bug.
1845 config APM_DO_ENABLE
1846 bool "Enable PM at boot time"
1848 Enable APM features at boot time. From page 36 of the APM BIOS
1849 specification: "When disabled, the APM BIOS does not automatically
1850 power manage devices, enter the Standby State, enter the Suspend
1851 State, or take power saving steps in response to CPU Idle calls."
1852 This driver will make CPU Idle calls when Linux is idle (unless this
1853 feature is turned off -- see "Do CPU IDLE calls", below). This
1854 should always save battery power, but more complicated APM features
1855 will be dependent on your BIOS implementation. You may need to turn
1856 this option off if your computer hangs at boot time when using APM
1857 support, or if it beeps continuously instead of suspending. Turn
1858 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1859 T400CDT. This is off by default since most machines do fine without
1863 bool "Make CPU Idle calls when idle"
1865 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1866 On some machines, this can activate improved power savings, such as
1867 a slowed CPU clock rate, when the machine is idle. These idle calls
1868 are made after the idle loop has run for some length of time (e.g.,
1869 333 mS). On some machines, this will cause a hang at boot time or
1870 whenever the CPU becomes idle. (On machines with more than one CPU,
1871 this option does nothing.)
1873 config APM_DISPLAY_BLANK
1874 bool "Enable console blanking using APM"
1876 Enable console blanking using the APM. Some laptops can use this to
1877 turn off the LCD backlight when the screen blanker of the Linux
1878 virtual console blanks the screen. Note that this is only used by
1879 the virtual console screen blanker, and won't turn off the backlight
1880 when using the X Window system. This also doesn't have anything to
1881 do with your VESA-compliant power-saving monitor. Further, this
1882 option doesn't work for all laptops -- it might not turn off your
1883 backlight at all, or it might print a lot of errors to the console,
1884 especially if you are using gpm.
1886 config APM_ALLOW_INTS
1887 bool "Allow interrupts during APM BIOS calls"
1889 Normally we disable external interrupts while we are making calls to
1890 the APM BIOS as a measure to lessen the effects of a badly behaving
1891 BIOS implementation. The BIOS should reenable interrupts if it
1892 needs to. Unfortunately, some BIOSes do not -- especially those in
1893 many of the newer IBM Thinkpads. If you experience hangs when you
1894 suspend, try setting this to Y. Otherwise, say N.
1898 source "drivers/cpufreq/Kconfig"
1900 source "drivers/cpuidle/Kconfig"
1902 source "drivers/idle/Kconfig"
1907 menu "Bus options (PCI etc.)"
1912 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1914 Find out whether you have a PCI motherboard. PCI is the name of a
1915 bus system, i.e. the way the CPU talks to the other stuff inside
1916 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1917 VESA. If you have PCI, say Y, otherwise N.
1920 prompt "PCI access mode"
1921 depends on X86_32 && PCI
1924 On PCI systems, the BIOS can be used to detect the PCI devices and
1925 determine their configuration. However, some old PCI motherboards
1926 have BIOS bugs and may crash if this is done. Also, some embedded
1927 PCI-based systems don't have any BIOS at all. Linux can also try to
1928 detect the PCI hardware directly without using the BIOS.
1930 With this option, you can specify how Linux should detect the
1931 PCI devices. If you choose "BIOS", the BIOS will be used,
1932 if you choose "Direct", the BIOS won't be used, and if you
1933 choose "MMConfig", then PCI Express MMCONFIG will be used.
1934 If you choose "Any", the kernel will try MMCONFIG, then the
1935 direct access method and falls back to the BIOS if that doesn't
1936 work. If unsure, go with the default, which is "Any".
1941 config PCI_GOMMCONFIG
1958 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1960 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1963 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1967 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1971 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1975 depends on PCI && XEN
1983 bool "Support mmconfig PCI config space access"
1984 depends on X86_64 && PCI && ACPI
1986 config PCI_CNB20LE_QUIRK
1987 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1989 depends on PCI && EXPERIMENTAL
1991 Read the PCI windows out of the CNB20LE host bridge. This allows
1992 PCI hotplug to work on systems with the CNB20LE chipset which do
1995 There's no public spec for this chipset, and this functionality
1996 is known to be incomplete.
1998 You should say N unless you know you need this.
2000 source "drivers/pci/pcie/Kconfig"
2002 source "drivers/pci/Kconfig"
2004 # x86_64 have no ISA slots, but can have ISA-style DMA.
2006 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2009 Enables ISA-style DMA support for devices requiring such controllers.
2017 Find out whether you have ISA slots on your motherboard. ISA is the
2018 name of a bus system, i.e. the way the CPU talks to the other stuff
2019 inside your box. Other bus systems are PCI, EISA, MicroChannel
2020 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2021 newer boards don't support it. If you have ISA, say Y, otherwise N.
2027 The Extended Industry Standard Architecture (EISA) bus was
2028 developed as an open alternative to the IBM MicroChannel bus.
2030 The EISA bus provided some of the features of the IBM MicroChannel
2031 bus while maintaining backward compatibility with cards made for
2032 the older ISA bus. The EISA bus saw limited use between 1988 and
2033 1995 when it was made obsolete by the PCI bus.
2035 Say Y here if you are building a kernel for an EISA-based machine.
2039 source "drivers/eisa/Kconfig"
2044 MicroChannel Architecture is found in some IBM PS/2 machines and
2045 laptops. It is a bus system similar to PCI or ISA. See
2046 <file:Documentation/mca.txt> (and especially the web page given
2047 there) before attempting to build an MCA bus kernel.
2049 source "drivers/mca/Kconfig"
2052 tristate "NatSemi SCx200 support"
2054 This provides basic support for National Semiconductor's
2055 (now AMD's) Geode processors. The driver probes for the
2056 PCI-IDs of several on-chip devices, so its a good dependency
2057 for other scx200_* drivers.
2059 If compiled as a module, the driver is named scx200.
2061 config SCx200HR_TIMER
2062 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2066 This driver provides a clocksource built upon the on-chip
2067 27MHz high-resolution timer. Its also a workaround for
2068 NSC Geode SC-1100's buggy TSC, which loses time when the
2069 processor goes idle (as is done by the scheduler). The
2070 other workaround is idle=poll boot option.
2073 bool "One Laptop Per Child support"
2079 Add support for detecting the unique features of the OLPC
2083 bool "OLPC XO-1 Power Management"
2084 depends on OLPC && MFD_CS5535 && PM_SLEEP
2087 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2090 bool "OLPC XO-1 Real Time Clock"
2091 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2093 Add support for the XO-1 real time clock, which can be used as a
2094 programmable wakeup source.
2097 bool "OLPC XO-1 SCI extras"
2098 depends on OLPC && OLPC_XO1_PM
2103 Add support for SCI-based features of the OLPC XO-1 laptop:
2104 - EC-driven system wakeups
2108 - AC adapter status updates
2109 - Battery status updates
2111 config OLPC_XO15_SCI
2112 bool "OLPC XO-1.5 SCI extras"
2113 depends on OLPC && ACPI
2116 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2117 - EC-driven system wakeups
2118 - AC adapter status updates
2119 - Battery status updates
2122 bool "PCEngines ALIX System Support (LED setup)"
2125 This option enables system support for the PCEngines ALIX.
2126 At present this just sets up LEDs for GPIO control on
2127 ALIX2/3/6 boards. However, other system specific setup should
2130 Note: You must still enable the drivers for GPIO and LED support
2131 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2133 Note: You have to set alix.force=1 for boards with Award BIOS.
2139 depends on CPU_SUP_AMD && PCI
2141 source "drivers/pcmcia/Kconfig"
2143 source "drivers/pci/hotplug/Kconfig"
2146 bool "RapidIO support"
2150 If you say Y here, the kernel will include drivers and
2151 infrastructure code to support RapidIO interconnect devices.
2153 source "drivers/rapidio/Kconfig"
2158 menu "Executable file formats / Emulations"
2160 source "fs/Kconfig.binfmt"
2162 config IA32_EMULATION
2163 bool "IA32 Emulation"
2165 select COMPAT_BINFMT_ELF
2167 Include code to run 32-bit programs under a 64-bit kernel. You should
2168 likely turn this on, unless you're 100% sure that you don't have any
2169 32-bit programs left.
2172 tristate "IA32 a.out support"
2173 depends on IA32_EMULATION
2175 Support old a.out binaries in the 32bit emulation.
2179 depends on IA32_EMULATION
2181 config COMPAT_FOR_U64_ALIGNMENT
2185 config SYSVIPC_COMPAT
2187 depends on COMPAT && SYSVIPC
2191 depends on COMPAT && KEYS
2197 config HAVE_ATOMIC_IOMAP
2201 config HAVE_TEXT_POKE_SMP
2203 select STOP_MACHINE if SMP
2205 source "net/Kconfig"
2207 source "drivers/Kconfig"
2209 source "drivers/firmware/Kconfig"
2213 source "arch/x86/Kconfig.debug"
2215 source "security/Kconfig"
2217 source "crypto/Kconfig"
2219 source "arch/x86/kvm/Kconfig"
2221 source "lib/Kconfig"