3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select X86_DEV_DMA_OPS
23 select HAVE_AOUT if X86_32
24 select HAVE_UNSTABLE_SCHED_CLOCK
27 select HAVE_PCSPKR_PLATFORM
28 select HAVE_PERF_EVENTS
30 select HAVE_IOREMAP_PROT
33 select HAVE_MEMBLOCK_NODE_MAP
34 select ARCH_DISCARD_MEMBLOCK
35 select ARCH_WANT_OPTIONAL_GPIOLIB
36 select ARCH_WANT_FRAME_POINTERS
38 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
39 select HAVE_KRETPROBES
41 select HAVE_FTRACE_MCOUNT_RECORD
42 select HAVE_FENTRY if X86_64
43 select HAVE_C_RECORDMCOUNT
44 select HAVE_DYNAMIC_FTRACE
45 select HAVE_FUNCTION_TRACER
46 select HAVE_FUNCTION_GRAPH_TRACER
47 select HAVE_FUNCTION_GRAPH_FP_TEST
48 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
49 select HAVE_SYSCALL_TRACEPOINTS
52 select HAVE_ARCH_TRACEHOOK
53 select HAVE_GENERIC_DMA_COHERENT if X86_32
54 select HAVE_EFFICIENT_UNALIGNED_ACCESS
55 select USER_STACKTRACE_SUPPORT
56 select HAVE_REGS_AND_STACK_ACCESS_API
57 select HAVE_DMA_API_DEBUG
58 select HAVE_KERNEL_GZIP
59 select HAVE_KERNEL_BZIP2
60 select HAVE_KERNEL_LZMA
62 select HAVE_KERNEL_LZO
63 select HAVE_HW_BREAKPOINT
64 select HAVE_MIXED_BREAKPOINTS_REGS
66 select HAVE_PERF_EVENTS_NMI
68 select HAVE_PERF_USER_STACK_DUMP
70 select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386
71 select HAVE_CMPXCHG_LOCAL if !M386
72 select HAVE_CMPXCHG_DOUBLE
73 select HAVE_ARCH_KMEMCHECK
74 select HAVE_USER_RETURN_NOTIFIER
75 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
76 select HAVE_ARCH_JUMP_LABEL
77 select HAVE_TEXT_POKE_SMP
78 select HAVE_GENERIC_HARDIRQS
79 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
81 select GENERIC_FIND_FIRST_BIT
82 select GENERIC_IRQ_PROBE
83 select GENERIC_PENDING_IRQ if SMP
84 select GENERIC_IRQ_SHOW
85 select GENERIC_CLOCKEVENTS_MIN_ADJUST
86 select IRQ_FORCED_THREADING
87 select USE_GENERIC_SMP_HELPERS if SMP
88 select HAVE_BPF_JIT if X86_64
90 select ARCH_HAVE_NMI_SAFE_CMPXCHG
92 select DCACHE_WORD_ACCESS
93 select GENERIC_SMP_IDLE_THREAD
94 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
95 select HAVE_ARCH_SECCOMP_FILTER
96 select BUILDTIME_EXTABLE_SORT
97 select GENERIC_CMOS_UPDATE
98 select CLOCKSOURCE_WATCHDOG
99 select GENERIC_CLOCKEVENTS
100 select ARCH_CLOCKSOURCE_DATA if X86_64
101 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
102 select GENERIC_TIME_VSYSCALL if X86_64
103 select KTIME_SCALAR if X86_32
104 select GENERIC_STRNCPY_FROM_USER
105 select GENERIC_STRNLEN_USER
106 select HAVE_RCU_USER_QS if X86_64
107 select HAVE_IRQ_TIME_ACCOUNTING
109 config INSTRUCTION_DECODER
111 depends on KPROBES || PERF_EVENTS || UPROBES
115 default "elf32-i386" if X86_32
116 default "elf64-x86-64" if X86_64
118 config ARCH_DEFCONFIG
120 default "arch/x86/configs/i386_defconfig" if X86_32
121 default "arch/x86/configs/x86_64_defconfig" if X86_64
123 config LOCKDEP_SUPPORT
126 config STACKTRACE_SUPPORT
129 config HAVE_LATENCYTOP_SUPPORT
138 config NEED_DMA_MAP_STATE
140 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
142 config NEED_SG_DMA_LENGTH
145 config GENERIC_ISA_DMA
147 depends on ISA_DMA_API
152 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
154 config GENERIC_BUG_RELATIVE_POINTERS
157 config GENERIC_HWEIGHT
163 config ARCH_MAY_HAVE_PC_FDC
165 depends on ISA_DMA_API
167 config RWSEM_GENERIC_SPINLOCK
171 config RWSEM_XCHGADD_ALGORITHM
175 config GENERIC_CALIBRATE_DELAY
178 config ARCH_HAS_CPU_RELAX
181 config ARCH_HAS_DEFAULT_IDLE
184 config ARCH_HAS_CACHE_LINE_SIZE
187 config ARCH_HAS_CPU_AUTOPROBE
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
244 config ARCH_CPU_PROBE_RELEASE
246 depends on HOTPLUG_CPU
248 config ARCH_SUPPORTS_UPROBES
251 source "init/Kconfig"
252 source "kernel/Kconfig.freezer"
254 menu "Processor type and features"
257 bool "DMA memory allocation support" if EXPERT
260 DMA memory allocation support allows devices with less than 32-bit
261 addressing to allocate within the first 16MB of address space.
262 Disable if no such devices will be used.
267 bool "Symmetric multi-processing support"
269 This enables support for systems with more than one CPU. If you have
270 a system with only one CPU, like most personal computers, say N. If
271 you have a system with more than one CPU, say Y.
273 If you say N here, the kernel will run on single and multiprocessor
274 machines, but will use only one CPU of a multiprocessor machine. If
275 you say Y here, the kernel will run on many, but not all,
276 singleprocessor machines. On a singleprocessor machine, the kernel
277 will run faster if you say N here.
279 Note that if you say Y here and choose architecture "586" or
280 "Pentium" under "Processor family", the kernel will not work on 486
281 architectures. Similarly, multiprocessor kernels for the "PPro"
282 architecture may not work on all Pentium based boards.
284 People using multiprocessor machines who say Y here should also say
285 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
286 Management" code will be disabled if you say Y here.
288 See also <file:Documentation/x86/i386/IO-APIC.txt>,
289 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
290 <http://www.tldp.org/docs.html#howto>.
292 If you don't know what to do here, say N.
295 bool "Support x2apic"
296 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
298 This enables x2apic support on CPUs that have this feature.
300 This allows 32-bit apic IDs (so it can support very large systems),
301 and accesses the local apic via MSRs not via mmio.
303 If you don't know what to do here, say N.
306 bool "Enable MPS table" if ACPI
308 depends on X86_LOCAL_APIC
310 For old smp systems that do not have proper acpi support. Newer systems
311 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
314 bool "Support for big SMP systems with more than 8 CPUs"
315 depends on X86_32 && SMP
317 This option is needed for the systems that have more than 8 CPUs
320 config X86_EXTENDED_PLATFORM
321 bool "Support for extended (non-PC) x86 platforms"
324 If you disable this option then the kernel will only support
325 standard PC platforms. (which covers the vast majority of
328 If you enable this option then you'll be able to select support
329 for the following (non-PC) 32 bit x86 platforms:
333 SGI 320/540 (Visual Workstation)
334 STA2X11-based (e.g. Northville)
335 Summit/EXA (IBM x440)
336 Unisys ES7000 IA32 series
337 Moorestown MID devices
339 If you have one of these systems, or if you want to build a
340 generic distribution kernel, say Y here - otherwise say N.
344 config X86_EXTENDED_PLATFORM
345 bool "Support for extended (non-PC) x86 platforms"
348 If you disable this option then the kernel will only support
349 standard PC platforms. (which covers the vast majority of
352 If you enable this option then you'll be able to select support
353 for the following (non-PC) 64 bit x86 platforms:
358 If you have one of these systems, or if you want to build a
359 generic distribution kernel, say Y here - otherwise say N.
361 # This is an alphabetically sorted list of 64 bit extended platforms
362 # Please maintain the alphabetic order if and when there are additions
364 bool "Numascale NumaChip"
366 depends on X86_EXTENDED_PLATFORM
369 depends on X86_X2APIC
371 Adds support for Numascale NumaChip large-SMP systems. Needed to
372 enable more than ~168 cores.
373 If you don't have one of these, you should say N here.
377 select PARAVIRT_GUEST
379 depends on X86_64 && PCI
380 depends on X86_EXTENDED_PLATFORM
383 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
384 supposed to run on these EM64T-based machines. Only choose this option
385 if you have one of these machines.
388 bool "SGI Ultraviolet"
390 depends on X86_EXTENDED_PLATFORM
392 depends on X86_X2APIC
394 This option is needed in order to support SGI Ultraviolet systems.
395 If you don't have one of these, you should say N here.
397 # Following is an alphabetically sorted list of 32 bit extended platforms
398 # Please maintain the alphabetic order if and when there are additions
401 bool "CE4100 TV platform"
403 depends on PCI_GODIRECT
405 depends on X86_EXTENDED_PLATFORM
406 select X86_REBOOTFIXUPS
408 select OF_EARLY_FLATTREE
411 Select for the Intel CE media processor (CE4100) SOC.
412 This option compiles in support for the CE4100 SOC for settop
413 boxes and media devices.
415 config X86_WANT_INTEL_MID
416 bool "Intel MID platform support"
418 depends on X86_EXTENDED_PLATFORM
420 Select to build a kernel capable of supporting Intel MID platform
421 systems which do not have the PCI legacy interfaces (Moorestown,
422 Medfield). If you are building for a PC class system say N here.
424 if X86_WANT_INTEL_MID
430 bool "Medfield MID platform"
433 depends on X86_IO_APIC
441 select X86_PLATFORM_DEVICES
442 select MFD_INTEL_MSIC
444 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
445 Internet Device(MID) platform.
446 Unlike standard x86 PCs, Medfield does not have many legacy devices
447 nor standard legacy replacement devices/features. e.g. Medfield does
448 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
453 bool "RDC R-321x SoC"
455 depends on X86_EXTENDED_PLATFORM
457 select X86_REBOOTFIXUPS
459 This option is needed for RDC R-321x system-on-chip, also known
461 If you don't have one of these chips, you should say N here.
463 config X86_32_NON_STANDARD
464 bool "Support non-standard 32-bit SMP architectures"
465 depends on X86_32 && SMP
466 depends on X86_EXTENDED_PLATFORM
468 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
469 STA2X11, default subarchitectures. It is intended for a generic
470 binary kernel. If you select them all, kernel will probe it
471 one by one and will fallback to default.
473 # Alphabetically sorted list of Non standard 32 bit platforms
476 bool "NUMAQ (IBM/Sequent)"
477 depends on X86_32_NON_STANDARD
482 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
483 NUMA multiquad box. This changes the way that processors are
484 bootstrapped, and uses Clustered Logical APIC addressing mode instead
485 of Flat Logical. You will need a new lynxer.elf file to flash your
486 firmware with - send email to <Martin.Bligh@us.ibm.com>.
488 config X86_SUPPORTS_MEMORY_FAILURE
490 # MCE code calls memory_failure():
492 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
493 depends on !X86_NUMAQ
494 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
495 depends on X86_64 || !SPARSEMEM
496 select ARCH_SUPPORTS_MEMORY_FAILURE
499 bool "SGI 320/540 (Visual Workstation)"
500 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
501 depends on X86_32_NON_STANDARD
503 The SGI Visual Workstation series is an IA32-based workstation
504 based on SGI systems chips with some legacy PC hardware attached.
506 Say Y here to create a kernel to run on the SGI 320 or 540.
508 A kernel compiled for the Visual Workstation will run on general
509 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
512 bool "STA2X11 Companion Chip Support"
513 depends on X86_32_NON_STANDARD && PCI
514 select X86_DEV_DMA_OPS
518 select ARCH_REQUIRE_GPIOLIB
521 This adds support for boards based on the STA2X11 IO-Hub,
522 a.k.a. "ConneXt". The chip is used in place of the standard
523 PC chipset, so all "standard" peripherals are missing. If this
524 option is selected the kernel will still be able to boot on
525 standard PC machines.
528 bool "Summit/EXA (IBM x440)"
529 depends on X86_32_NON_STANDARD
531 This option is needed for IBM systems that use the Summit/EXA chipset.
532 In particular, it is needed for the x440.
535 bool "Unisys ES7000 IA32 series"
536 depends on X86_32_NON_STANDARD && X86_BIGSMP
538 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
539 supposed to run on an IA32-based Unisys ES7000 system.
542 tristate "Eurobraille/Iris poweroff module"
545 The Iris machines from EuroBraille do not have APM or ACPI support
546 to shut themselves down properly. A special I/O sequence is
547 needed to do so, which is what this module does at
550 This is only for Iris machines from EuroBraille.
554 config SCHED_OMIT_FRAME_POINTER
556 prompt "Single-depth WCHAN output"
559 Calculate simpler /proc/<PID>/wchan values. If this option
560 is disabled then wchan values will recurse back to the
561 caller function. This provides more accurate wchan values,
562 at the expense of slightly more scheduling overhead.
564 If in doubt, say "Y".
566 menuconfig PARAVIRT_GUEST
567 bool "Paravirtualized guest support"
569 Say Y here to get to see options related to running Linux under
570 various hypervisors. This option alone does not add any kernel code.
572 If you say N, all options in this submenu will be skipped and disabled.
576 config PARAVIRT_TIME_ACCOUNTING
577 bool "Paravirtual steal time accounting"
581 Select this option to enable fine granularity task steal time
582 accounting. Time spent executing other tasks in parallel with
583 the current vCPU is discounted from the vCPU power. To account for
584 that, there can be a small performance impact.
586 If in doubt, say N here.
588 source "arch/x86/xen/Kconfig"
591 bool "KVM Guest support (including kvmclock)"
594 select PARAVIRT_CLOCK
595 default y if PARAVIRT_GUEST
597 This option enables various optimizations for running under the KVM
598 hypervisor. It includes a paravirtualized clock, so that instead
599 of relying on a PIT (or probably other) emulation by the
600 underlying device model, the host provides the guest with
601 timing infrastructure such as time of day, and system time
603 source "arch/x86/lguest/Kconfig"
606 bool "Enable paravirtualization code"
608 This changes the kernel so it can modify itself when it is run
609 under a hypervisor, potentially improving performance significantly
610 over full virtualization. However, when run without a hypervisor
611 the kernel is theoretically slower and slightly larger.
613 config PARAVIRT_SPINLOCKS
614 bool "Paravirtualization layer for spinlocks"
615 depends on PARAVIRT && SMP && EXPERIMENTAL
617 Paravirtualized spinlocks allow a pvops backend to replace the
618 spinlock implementation with something virtualization-friendly
619 (for example, block the virtual CPU rather than spinning).
621 Unfortunately the downside is an up to 5% performance hit on
622 native kernels, with various workloads.
624 If you are unsure how to answer this question, answer N.
626 config PARAVIRT_CLOCK
631 config PARAVIRT_DEBUG
632 bool "paravirt-ops debugging"
633 depends on PARAVIRT && DEBUG_KERNEL
635 Enable to debug paravirt_ops internals. Specifically, BUG if
636 a paravirt_op is missing when it is called.
644 This option adds a kernel parameter 'memtest', which allows memtest
646 memtest=0, mean disabled; -- default
647 memtest=1, mean do 1 test pattern;
649 memtest=4, mean do 4 test patterns.
650 If you are unsure how to answer this question, answer N.
652 config X86_SUMMIT_NUMA
654 depends on X86_32 && NUMA && X86_32_NON_STANDARD
656 config X86_CYCLONE_TIMER
658 depends on X86_SUMMIT
660 source "arch/x86/Kconfig.cpu"
664 prompt "HPET Timer Support" if X86_32
666 Use the IA-PC HPET (High Precision Event Timer) to manage
667 time in preference to the PIT and RTC, if a HPET is
669 HPET is the next generation timer replacing legacy 8254s.
670 The HPET provides a stable time base on SMP
671 systems, unlike the TSC, but it is more expensive to access,
672 as it is off-chip. You can find the HPET spec at
673 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
675 You can safely choose Y here. However, HPET will only be
676 activated if the platform and the BIOS support this feature.
677 Otherwise the 8254 will be used for timing services.
679 Choose N to continue using the legacy 8254 timer.
681 config HPET_EMULATE_RTC
683 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
686 def_bool y if X86_INTEL_MID
687 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
689 depends on X86_INTEL_MID && SFI
691 APB timer is the replacement for 8254, HPET on X86 MID platforms.
692 The APBT provides a stable time base on SMP
693 systems, unlike the TSC, but it is more expensive to access,
694 as it is off-chip. APB timers are always running regardless of CPU
695 C states, they are used as per CPU clockevent device when possible.
697 # Mark as expert because too many people got it wrong.
698 # The code disables itself when not needed.
701 bool "Enable DMI scanning" if EXPERT
703 Enabled scanning of DMI to identify machine quirks. Say Y
704 here unless you have verified that your setup is not
705 affected by entries in the DMI blacklist. Required by PNP
709 bool "GART IOMMU support" if EXPERT
712 depends on X86_64 && PCI && AMD_NB
714 Support for full DMA access of devices with 32bit memory access only
715 on systems with more than 3GB. This is usually needed for USB,
716 sound, many IDE/SATA chipsets and some other devices.
717 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
718 based hardware IOMMU and a software bounce buffer based IOMMU used
719 on Intel systems and as fallback.
720 The code is only active when needed (enough memory and limited
721 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
725 bool "IBM Calgary IOMMU support"
727 depends on X86_64 && PCI && EXPERIMENTAL
729 Support for hardware IOMMUs in IBM's xSeries x366 and x460
730 systems. Needed to run systems with more than 3GB of memory
731 properly with 32-bit PCI devices that do not support DAC
732 (Double Address Cycle). Calgary also supports bus level
733 isolation, where all DMAs pass through the IOMMU. This
734 prevents them from going anywhere except their intended
735 destination. This catches hard-to-find kernel bugs and
736 mis-behaving drivers and devices that do not use the DMA-API
737 properly to set up their DMA buffers. The IOMMU can be
738 turned off at boot time with the iommu=off parameter.
739 Normally the kernel will make the right choice by itself.
742 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
744 prompt "Should Calgary be enabled by default?"
745 depends on CALGARY_IOMMU
747 Should Calgary be enabled by default? if you choose 'y', Calgary
748 will be used (if it exists). If you choose 'n', Calgary will not be
749 used even if it exists. If you choose 'n' and would like to use
750 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
753 # need this always selected by IOMMU for the VIA workaround
757 Support for software bounce buffers used on x86-64 systems
758 which don't have a hardware IOMMU. Using this PCI devices
759 which can only access 32-bits of memory can be used on systems
760 with more than 3 GB of memory.
765 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
768 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
769 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
770 select CPUMASK_OFFSTACK
772 Enable maximum number of CPUS and NUMA Nodes for this architecture.
776 int "Maximum number of CPUs" if SMP && !MAXSMP
777 range 2 8 if SMP && X86_32 && !X86_BIGSMP
778 range 2 512 if SMP && !MAXSMP
780 default "4096" if MAXSMP
781 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
784 This allows you to specify the maximum number of CPUs which this
785 kernel will support. The maximum supported value is 512 and the
786 minimum value which makes sense is 2.
788 This is purely to save memory - each supported CPU adds
789 approximately eight kilobytes to the kernel image.
792 bool "SMT (Hyperthreading) scheduler support"
795 SMT scheduler support improves the CPU scheduler's decision making
796 when dealing with Intel Pentium 4 chips with HyperThreading at a
797 cost of slightly increased overhead in some places. If unsure say
802 prompt "Multi-core scheduler support"
805 Multi-core scheduler support improves the CPU scheduler's decision
806 making when dealing with multi-core CPU chips at a cost of slightly
807 increased overhead in some places. If unsure say N here.
809 source "kernel/Kconfig.preempt"
812 bool "Local APIC support on uniprocessors"
813 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
815 A local APIC (Advanced Programmable Interrupt Controller) is an
816 integrated interrupt controller in the CPU. If you have a single-CPU
817 system which has a processor with a local APIC, you can say Y here to
818 enable and use it. If you say Y here even though your machine doesn't
819 have a local APIC, then the kernel will still run with no slowdown at
820 all. The local APIC supports CPU-generated self-interrupts (timer,
821 performance counters), and the NMI watchdog which detects hard
825 bool "IO-APIC support on uniprocessors"
826 depends on X86_UP_APIC
828 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
829 SMP-capable replacement for PC-style interrupt controllers. Most
830 SMP systems and many recent uniprocessor systems have one.
832 If you have a single-CPU system with an IO-APIC, you can say Y here
833 to use it. If you say Y here even though your machine doesn't have
834 an IO-APIC, then the kernel will still run with no slowdown at all.
836 config X86_LOCAL_APIC
838 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
842 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
844 config X86_VISWS_APIC
846 depends on X86_32 && X86_VISWS
848 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
849 bool "Reroute for broken boot IRQs"
850 depends on X86_IO_APIC
852 This option enables a workaround that fixes a source of
853 spurious interrupts. This is recommended when threaded
854 interrupt handling is used on systems where the generation of
855 superfluous "boot interrupts" cannot be disabled.
857 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
858 entry in the chipset's IO-APIC is masked (as, e.g. the RT
859 kernel does during interrupt handling). On chipsets where this
860 boot IRQ generation cannot be disabled, this workaround keeps
861 the original IRQ line masked so that only the equivalent "boot
862 IRQ" is delivered to the CPUs. The workaround also tells the
863 kernel to set up the IRQ handler on the boot IRQ line. In this
864 way only one interrupt is delivered to the kernel. Otherwise
865 the spurious second interrupt may cause the kernel to bring
866 down (vital) interrupt lines.
868 Only affects "broken" chipsets. Interrupt sharing may be
869 increased on these systems.
872 bool "Machine Check / overheating reporting"
875 Machine Check support allows the processor to notify the
876 kernel if it detects a problem (e.g. overheating, data corruption).
877 The action the kernel takes depends on the severity of the problem,
878 ranging from warning messages to halting the machine.
882 prompt "Intel MCE features"
883 depends on X86_MCE && X86_LOCAL_APIC
885 Additional support for intel specific MCE features such as
890 prompt "AMD MCE features"
891 depends on X86_MCE && X86_LOCAL_APIC
893 Additional support for AMD specific MCE features such as
894 the DRAM Error Threshold.
896 config X86_ANCIENT_MCE
897 bool "Support for old Pentium 5 / WinChip machine checks"
898 depends on X86_32 && X86_MCE
900 Include support for machine check handling on old Pentium 5 or WinChip
901 systems. These typically need to be enabled explicitely on the command
904 config X86_MCE_THRESHOLD
905 depends on X86_MCE_AMD || X86_MCE_INTEL
908 config X86_MCE_INJECT
910 tristate "Machine check injector support"
912 Provide support for injecting machine checks for testing purposes.
913 If you don't know what a machine check is and you don't do kernel
914 QA it is safe to say n.
916 config X86_THERMAL_VECTOR
918 depends on X86_MCE_INTEL
921 bool "Enable VM86 support" if EXPERT
925 This option is required by programs like DOSEMU to run 16-bit legacy
926 code on X86 processors. It also may be needed by software like
927 XFree86 to initialize some video cards via BIOS. Disabling this
928 option saves about 6k.
931 tristate "Toshiba Laptop support"
934 This adds a driver to safely access the System Management Mode of
935 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
936 not work on models with a Phoenix BIOS. The System Management Mode
937 is used to set the BIOS and power saving options on Toshiba portables.
939 For information on utilities to make use of this driver see the
940 Toshiba Linux utilities web site at:
941 <http://www.buzzard.org.uk/toshiba/>.
943 Say Y if you intend to run this kernel on a Toshiba portable.
947 tristate "Dell laptop support"
950 This adds a driver to safely access the System Management Mode
951 of the CPU on the Dell Inspiron 8000. The System Management Mode
952 is used to read cpu temperature and cooling fan status and to
953 control the fans on the I8K portables.
955 This driver has been tested only on the Inspiron 8000 but it may
956 also work with other Dell laptops. You can force loading on other
957 models by passing the parameter `force=1' to the module. Use at
960 For information on utilities to make use of this driver see the
961 I8K Linux utilities web site at:
962 <http://people.debian.org/~dz/i8k/>
964 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
967 config X86_REBOOTFIXUPS
968 bool "Enable X86 board specific fixups for reboot"
971 This enables chipset and/or board specific fixups to be done
972 in order to get reboot to work correctly. This is only needed on
973 some combinations of hardware and BIOS. The symptom, for which
974 this config is intended, is when reboot ends with a stalled/hung
977 Currently, the only fixup is for the Geode machines using
978 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
980 Say Y if you want to enable the fixup. Currently, it's safe to
981 enable this option even if you don't need it.
985 tristate "CPU microcode loading support"
989 If you say Y here, you will be able to update the microcode on
990 certain Intel and AMD processors. The Intel support is for the
991 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
992 Xeon etc. The AMD support is for families 0x10 and later. You will
993 obviously need the actual microcode binary data itself which is not
994 shipped with the Linux kernel.
996 This option selects the general module only, you need to select
997 at least one vendor specific module as well.
999 To compile this driver as a module, choose M here: the module
1000 will be called microcode.
1002 config MICROCODE_INTEL
1003 bool "Intel microcode loading support"
1004 depends on MICROCODE
1008 This options enables microcode patch loading support for Intel
1011 For latest news and information on obtaining all the required
1012 Intel ingredients for this driver, check:
1013 <http://www.urbanmyth.org/microcode/>.
1015 config MICROCODE_AMD
1016 bool "AMD microcode loading support"
1017 depends on MICROCODE
1020 If you select this option, microcode patch loading support for AMD
1021 processors will be enabled.
1023 config MICROCODE_OLD_INTERFACE
1025 depends on MICROCODE
1028 tristate "/dev/cpu/*/msr - Model-specific register support"
1030 This device gives privileged processes access to the x86
1031 Model-Specific Registers (MSRs). It is a character device with
1032 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1033 MSR accesses are directed to a specific CPU on multi-processor
1037 tristate "/dev/cpu/*/cpuid - CPU information support"
1039 This device gives processes access to the x86 CPUID instruction to
1040 be executed on a specific processor. It is a character device
1041 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1045 prompt "High Memory Support"
1046 default HIGHMEM64G if X86_NUMAQ
1052 depends on !X86_NUMAQ
1054 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1055 However, the address space of 32-bit x86 processors is only 4
1056 Gigabytes large. That means that, if you have a large amount of
1057 physical memory, not all of it can be "permanently mapped" by the
1058 kernel. The physical memory that's not permanently mapped is called
1061 If you are compiling a kernel which will never run on a machine with
1062 more than 1 Gigabyte total physical RAM, answer "off" here (default
1063 choice and suitable for most users). This will result in a "3GB/1GB"
1064 split: 3GB are mapped so that each process sees a 3GB virtual memory
1065 space and the remaining part of the 4GB virtual memory space is used
1066 by the kernel to permanently map as much physical memory as
1069 If the machine has between 1 and 4 Gigabytes physical RAM, then
1072 If more than 4 Gigabytes is used then answer "64GB" here. This
1073 selection turns Intel PAE (Physical Address Extension) mode on.
1074 PAE implements 3-level paging on IA32 processors. PAE is fully
1075 supported by Linux, PAE mode is implemented on all recent Intel
1076 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1077 then the kernel will not boot on CPUs that don't support PAE!
1079 The actual amount of total physical memory will either be
1080 auto detected or can be forced by using a kernel command line option
1081 such as "mem=256M". (Try "man bootparam" or see the documentation of
1082 your boot loader (lilo or loadlin) about how to pass options to the
1083 kernel at boot time.)
1085 If unsure, say "off".
1089 depends on !X86_NUMAQ
1091 Select this if you have a 32-bit processor and between 1 and 4
1092 gigabytes of physical RAM.
1096 depends on !M386 && !M486
1099 Select this if you have a 32-bit processor and more than 4
1100 gigabytes of physical RAM.
1105 depends on EXPERIMENTAL
1106 prompt "Memory split" if EXPERT
1110 Select the desired split between kernel and user memory.
1112 If the address range available to the kernel is less than the
1113 physical memory installed, the remaining memory will be available
1114 as "high memory". Accessing high memory is a little more costly
1115 than low memory, as it needs to be mapped into the kernel first.
1116 Note that increasing the kernel address space limits the range
1117 available to user programs, making the address space there
1118 tighter. Selecting anything other than the default 3G/1G split
1119 will also likely make your kernel incompatible with binary-only
1122 If you are not absolutely sure what you are doing, leave this
1126 bool "3G/1G user/kernel split"
1127 config VMSPLIT_3G_OPT
1129 bool "3G/1G user/kernel split (for full 1G low memory)"
1131 bool "2G/2G user/kernel split"
1132 config VMSPLIT_2G_OPT
1134 bool "2G/2G user/kernel split (for full 2G low memory)"
1136 bool "1G/3G user/kernel split"
1141 default 0xB0000000 if VMSPLIT_3G_OPT
1142 default 0x80000000 if VMSPLIT_2G
1143 default 0x78000000 if VMSPLIT_2G_OPT
1144 default 0x40000000 if VMSPLIT_1G
1150 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1153 bool "PAE (Physical Address Extension) Support"
1154 depends on X86_32 && !HIGHMEM4G
1156 PAE is required for NX support, and furthermore enables
1157 larger swapspace support for non-overcommit purposes. It
1158 has the cost of more pagetable lookup overhead, and also
1159 consumes more pagetable space per process.
1161 config ARCH_PHYS_ADDR_T_64BIT
1163 depends on X86_64 || X86_PAE
1165 config ARCH_DMA_ADDR_T_64BIT
1167 depends on X86_64 || HIGHMEM64G
1169 config DIRECT_GBPAGES
1170 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1174 Allow the kernel linear mapping to use 1GB pages on CPUs that
1175 support it. This can improve the kernel's performance a tiny bit by
1176 reducing TLB pressure. If in doubt, say "Y".
1178 # Common NUMA Features
1180 bool "Numa Memory Allocation and Scheduler Support"
1182 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1183 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1185 Enable NUMA (Non Uniform Memory Access) support.
1187 The kernel will try to allocate memory used by a CPU on the
1188 local memory controller of the CPU and add some more
1189 NUMA awareness to the kernel.
1191 For 64-bit this is recommended if the system is Intel Core i7
1192 (or later), AMD Opteron, or EM64T NUMA.
1194 For 32-bit this is only needed on (rare) 32-bit-only platforms
1195 that support NUMA topologies, such as NUMAQ / Summit, or if you
1196 boot a 32-bit kernel on a 64-bit NUMA platform.
1198 Otherwise, you should say N.
1200 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1201 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1205 prompt "Old style AMD Opteron NUMA detection"
1206 depends on X86_64 && NUMA && PCI
1208 Enable AMD NUMA node topology detection. You should say Y here if
1209 you have a multi processor AMD system. This uses an old method to
1210 read the NUMA configuration directly from the builtin Northbridge
1211 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1212 which also takes priority if both are compiled in.
1214 config X86_64_ACPI_NUMA
1216 prompt "ACPI NUMA detection"
1217 depends on X86_64 && NUMA && ACPI && PCI
1220 Enable ACPI SRAT based node topology detection.
1222 # Some NUMA nodes have memory ranges that span
1223 # other nodes. Even though a pfn is valid and
1224 # between a node's start and end pfns, it may not
1225 # reside on that node. See memmap_init_zone()
1227 config NODES_SPAN_OTHER_NODES
1229 depends on X86_64_ACPI_NUMA
1232 bool "NUMA emulation"
1235 Enable NUMA emulation. A flat machine will be split
1236 into virtual nodes when booted with "numa=fake=N", where N is the
1237 number of nodes. This is only useful for debugging.
1240 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1242 default "10" if MAXSMP
1243 default "6" if X86_64
1244 default "4" if X86_NUMAQ
1246 depends on NEED_MULTIPLE_NODES
1248 Specify the maximum number of NUMA Nodes available on the target
1249 system. Increases memory reserved to accommodate various tables.
1251 config HAVE_ARCH_ALLOC_REMAP
1253 depends on X86_32 && NUMA
1255 config ARCH_HAVE_MEMORY_PRESENT
1257 depends on X86_32 && DISCONTIGMEM
1259 config NEED_NODE_MEMMAP_SIZE
1261 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1263 config ARCH_FLATMEM_ENABLE
1265 depends on X86_32 && !NUMA
1267 config ARCH_DISCONTIGMEM_ENABLE
1269 depends on NUMA && X86_32
1271 config ARCH_DISCONTIGMEM_DEFAULT
1273 depends on NUMA && X86_32
1275 config ARCH_SPARSEMEM_ENABLE
1277 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1278 select SPARSEMEM_STATIC if X86_32
1279 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1281 config ARCH_SPARSEMEM_DEFAULT
1285 config ARCH_SELECT_MEMORY_MODEL
1287 depends on ARCH_SPARSEMEM_ENABLE
1289 config ARCH_MEMORY_PROBE
1291 depends on X86_64 && MEMORY_HOTPLUG
1293 config ARCH_PROC_KCORE_TEXT
1295 depends on X86_64 && PROC_KCORE
1297 config ILLEGAL_POINTER_VALUE
1300 default 0xdead000000000000 if X86_64
1305 bool "Allocate 3rd-level pagetables from highmem"
1308 The VM uses one page table entry for each page of physical memory.
1309 For systems with a lot of RAM, this can be wasteful of precious
1310 low memory. Setting this option will put user-space page table
1311 entries in high memory.
1313 config X86_CHECK_BIOS_CORRUPTION
1314 bool "Check for low memory corruption"
1316 Periodically check for memory corruption in low memory, which
1317 is suspected to be caused by BIOS. Even when enabled in the
1318 configuration, it is disabled at runtime. Enable it by
1319 setting "memory_corruption_check=1" on the kernel command
1320 line. By default it scans the low 64k of memory every 60
1321 seconds; see the memory_corruption_check_size and
1322 memory_corruption_check_period parameters in
1323 Documentation/kernel-parameters.txt to adjust this.
1325 When enabled with the default parameters, this option has
1326 almost no overhead, as it reserves a relatively small amount
1327 of memory and scans it infrequently. It both detects corruption
1328 and prevents it from affecting the running system.
1330 It is, however, intended as a diagnostic tool; if repeatable
1331 BIOS-originated corruption always affects the same memory,
1332 you can use memmap= to prevent the kernel from using that
1335 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1336 bool "Set the default setting of memory_corruption_check"
1337 depends on X86_CHECK_BIOS_CORRUPTION
1340 Set whether the default state of memory_corruption_check is
1343 config X86_RESERVE_LOW
1344 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1348 Specify the amount of low memory to reserve for the BIOS.
1350 The first page contains BIOS data structures that the kernel
1351 must not use, so that page must always be reserved.
1353 By default we reserve the first 64K of physical RAM, as a
1354 number of BIOSes are known to corrupt that memory range
1355 during events such as suspend/resume or monitor cable
1356 insertion, so it must not be used by the kernel.
1358 You can set this to 4 if you are absolutely sure that you
1359 trust the BIOS to get all its memory reservations and usages
1360 right. If you know your BIOS have problems beyond the
1361 default 64K area, you can set this to 640 to avoid using the
1362 entire low memory range.
1364 If you have doubts about the BIOS (e.g. suspend/resume does
1365 not work or there's kernel crashes after certain hardware
1366 hotplug events) then you might want to enable
1367 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1368 typical corruption patterns.
1370 Leave this to the default value of 64 if you are unsure.
1372 config MATH_EMULATION
1374 prompt "Math emulation" if X86_32
1376 Linux can emulate a math coprocessor (used for floating point
1377 operations) if you don't have one. 486DX and Pentium processors have
1378 a math coprocessor built in, 486SX and 386 do not, unless you added
1379 a 487DX or 387, respectively. (The messages during boot time can
1380 give you some hints here ["man dmesg"].) Everyone needs either a
1381 coprocessor or this emulation.
1383 If you don't have a math coprocessor, you need to say Y here; if you
1384 say Y here even though you have a coprocessor, the coprocessor will
1385 be used nevertheless. (This behavior can be changed with the kernel
1386 command line option "no387", which comes handy if your coprocessor
1387 is broken. Try "man bootparam" or see the documentation of your boot
1388 loader (lilo or loadlin) about how to pass options to the kernel at
1389 boot time.) This means that it is a good idea to say Y here if you
1390 intend to use this kernel on different machines.
1392 More information about the internals of the Linux math coprocessor
1393 emulation can be found in <file:arch/x86/math-emu/README>.
1395 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1396 kernel, it won't hurt.
1400 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1402 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1403 the Memory Type Range Registers (MTRRs) may be used to control
1404 processor access to memory ranges. This is most useful if you have
1405 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1406 allows bus write transfers to be combined into a larger transfer
1407 before bursting over the PCI/AGP bus. This can increase performance
1408 of image write operations 2.5 times or more. Saying Y here creates a
1409 /proc/mtrr file which may be used to manipulate your processor's
1410 MTRRs. Typically the X server should use this.
1412 This code has a reasonably generic interface so that similar
1413 control registers on other processors can be easily supported
1416 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1417 Registers (ARRs) which provide a similar functionality to MTRRs. For
1418 these, the ARRs are used to emulate the MTRRs.
1419 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1420 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1421 write-combining. All of these processors are supported by this code
1422 and it makes sense to say Y here if you have one of them.
1424 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1425 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1426 can lead to all sorts of problems, so it's good to say Y here.
1428 You can safely say Y even if your machine doesn't have MTRRs, you'll
1429 just add about 9 KB to your kernel.
1431 See <file:Documentation/x86/mtrr.txt> for more information.
1433 config MTRR_SANITIZER
1435 prompt "MTRR cleanup support"
1438 Convert MTRR layout from continuous to discrete, so X drivers can
1439 add writeback entries.
1441 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1442 The largest mtrr entry size for a continuous block can be set with
1447 config MTRR_SANITIZER_ENABLE_DEFAULT
1448 int "MTRR cleanup enable value (0-1)"
1451 depends on MTRR_SANITIZER
1453 Enable mtrr cleanup default value
1455 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1456 int "MTRR cleanup spare reg num (0-7)"
1459 depends on MTRR_SANITIZER
1461 mtrr cleanup spare entries default, it can be changed via
1462 mtrr_spare_reg_nr=N on the kernel command line.
1466 prompt "x86 PAT support" if EXPERT
1469 Use PAT attributes to setup page level cache control.
1471 PATs are the modern equivalents of MTRRs and are much more
1472 flexible than MTRRs.
1474 Say N here if you see bootup problems (boot crash, boot hang,
1475 spontaneous reboots) or a non-working video driver.
1479 config ARCH_USES_PG_UNCACHED
1485 prompt "x86 architectural random number generator" if EXPERT
1487 Enable the x86 architectural RDRAND instruction
1488 (Intel Bull Mountain technology) to generate random numbers.
1489 If supported, this is a high bandwidth, cryptographically
1490 secure hardware random number generator.
1494 prompt "Supervisor Mode Access Prevention" if EXPERT
1496 Supervisor Mode Access Prevention (SMAP) is a security
1497 feature in newer Intel processors. There is a small
1498 performance cost if this enabled and turned on; there is
1499 also a small increase in the kernel size if this is enabled.
1504 bool "EFI runtime service support"
1507 This enables the kernel to use EFI runtime services that are
1508 available (such as the EFI variable services).
1510 This option is only useful on systems that have EFI firmware.
1511 In addition, you should use the latest ELILO loader available
1512 at <http://elilo.sourceforge.net> in order to take advantage
1513 of EFI runtime services. However, even with this option, the
1514 resultant kernel should continue to boot on existing non-EFI
1518 bool "EFI stub support"
1521 This kernel feature allows a bzImage to be loaded directly
1522 by EFI firmware without the use of a bootloader.
1524 See Documentation/x86/efi-stub.txt for more information.
1528 prompt "Enable seccomp to safely compute untrusted bytecode"
1530 This kernel feature is useful for number crunching applications
1531 that may need to compute untrusted bytecode during their
1532 execution. By using pipes or other transports made available to
1533 the process as file descriptors supporting the read/write
1534 syscalls, it's possible to isolate those applications in
1535 their own address space using seccomp. Once seccomp is
1536 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1537 and the task is only allowed to execute a few safe syscalls
1538 defined by each seccomp mode.
1540 If unsure, say Y. Only embedded should say N here.
1542 config CC_STACKPROTECTOR
1543 bool "Enable -fstack-protector buffer overflow detection"
1545 This option turns on the -fstack-protector GCC feature. This
1546 feature puts, at the beginning of functions, a canary value on
1547 the stack just before the return address, and validates
1548 the value just before actually returning. Stack based buffer
1549 overflows (that need to overwrite this return address) now also
1550 overwrite the canary, which gets detected and the attack is then
1551 neutralized via a kernel panic.
1553 This feature requires gcc version 4.2 or above, or a distribution
1554 gcc with the feature backported. Older versions are automatically
1555 detected and for those versions, this configuration option is
1556 ignored. (and a warning is printed during bootup)
1558 source kernel/Kconfig.hz
1561 bool "kexec system call"
1563 kexec is a system call that implements the ability to shutdown your
1564 current kernel, and to start another kernel. It is like a reboot
1565 but it is independent of the system firmware. And like a reboot
1566 you can start any kernel with it, not just Linux.
1568 The name comes from the similarity to the exec system call.
1570 It is an ongoing process to be certain the hardware in a machine
1571 is properly shutdown, so do not be surprised if this code does not
1572 initially work for you. It may help to enable device hotplugging
1573 support. As of this writing the exact hardware interface is
1574 strongly in flux, so no good recommendation can be made.
1577 bool "kernel crash dumps"
1578 depends on X86_64 || (X86_32 && HIGHMEM)
1580 Generate crash dump after being started by kexec.
1581 This should be normally only set in special crash dump kernels
1582 which are loaded in the main kernel with kexec-tools into
1583 a specially reserved region and then later executed after
1584 a crash by kdump/kexec. The crash dump kernel must be compiled
1585 to a memory address not used by the main kernel or BIOS using
1586 PHYSICAL_START, or it must be built as a relocatable image
1587 (CONFIG_RELOCATABLE=y).
1588 For more details see Documentation/kdump/kdump.txt
1591 bool "kexec jump (EXPERIMENTAL)"
1592 depends on EXPERIMENTAL
1593 depends on KEXEC && HIBERNATION
1595 Jump between original kernel and kexeced kernel and invoke
1596 code in physical address mode via KEXEC
1598 config PHYSICAL_START
1599 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1602 This gives the physical address where the kernel is loaded.
1604 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1605 bzImage will decompress itself to above physical address and
1606 run from there. Otherwise, bzImage will run from the address where
1607 it has been loaded by the boot loader and will ignore above physical
1610 In normal kdump cases one does not have to set/change this option
1611 as now bzImage can be compiled as a completely relocatable image
1612 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1613 address. This option is mainly useful for the folks who don't want
1614 to use a bzImage for capturing the crash dump and want to use a
1615 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1616 to be specifically compiled to run from a specific memory area
1617 (normally a reserved region) and this option comes handy.
1619 So if you are using bzImage for capturing the crash dump,
1620 leave the value here unchanged to 0x1000000 and set
1621 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1622 for capturing the crash dump change this value to start of
1623 the reserved region. In other words, it can be set based on
1624 the "X" value as specified in the "crashkernel=YM@XM"
1625 command line boot parameter passed to the panic-ed
1626 kernel. Please take a look at Documentation/kdump/kdump.txt
1627 for more details about crash dumps.
1629 Usage of bzImage for capturing the crash dump is recommended as
1630 one does not have to build two kernels. Same kernel can be used
1631 as production kernel and capture kernel. Above option should have
1632 gone away after relocatable bzImage support is introduced. But it
1633 is present because there are users out there who continue to use
1634 vmlinux for dump capture. This option should go away down the
1637 Don't change this unless you know what you are doing.
1640 bool "Build a relocatable kernel"
1643 This builds a kernel image that retains relocation information
1644 so it can be loaded someplace besides the default 1MB.
1645 The relocations tend to make the kernel binary about 10% larger,
1646 but are discarded at runtime.
1648 One use is for the kexec on panic case where the recovery kernel
1649 must live at a different physical address than the primary
1652 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1653 it has been loaded at and the compile time physical address
1654 (CONFIG_PHYSICAL_START) is ignored.
1656 # Relocation on x86-32 needs some additional build support
1657 config X86_NEED_RELOCS
1659 depends on X86_32 && RELOCATABLE
1661 config PHYSICAL_ALIGN
1662 hex "Alignment value to which kernel should be aligned" if X86_32
1664 range 0x2000 0x1000000
1666 This value puts the alignment restrictions on physical address
1667 where kernel is loaded and run from. Kernel is compiled for an
1668 address which meets above alignment restriction.
1670 If bootloader loads the kernel at a non-aligned address and
1671 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1672 address aligned to above value and run from there.
1674 If bootloader loads the kernel at a non-aligned address and
1675 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1676 load address and decompress itself to the address it has been
1677 compiled for and run from there. The address for which kernel is
1678 compiled already meets above alignment restrictions. Hence the
1679 end result is that kernel runs from a physical address meeting
1680 above alignment restrictions.
1682 Don't change this unless you know what you are doing.
1685 bool "Support for hot-pluggable CPUs"
1686 depends on SMP && HOTPLUG
1688 Say Y here to allow turning CPUs off and on. CPUs can be
1689 controlled through /sys/devices/system/cpu.
1690 ( Note: power management support will enable this option
1691 automatically on SMP systems. )
1692 Say N if you want to disable CPU hotplug.
1696 prompt "Compat VDSO support"
1697 depends on X86_32 || IA32_EMULATION
1699 Map the 32-bit VDSO to the predictable old-style address too.
1701 Say N here if you are running a sufficiently recent glibc
1702 version (2.3.3 or later), to remove the high-mapped
1703 VDSO mapping and to exclusively use the randomized VDSO.
1708 bool "Built-in kernel command line"
1710 Allow for specifying boot arguments to the kernel at
1711 build time. On some systems (e.g. embedded ones), it is
1712 necessary or convenient to provide some or all of the
1713 kernel boot arguments with the kernel itself (that is,
1714 to not rely on the boot loader to provide them.)
1716 To compile command line arguments into the kernel,
1717 set this option to 'Y', then fill in the
1718 the boot arguments in CONFIG_CMDLINE.
1720 Systems with fully functional boot loaders (i.e. non-embedded)
1721 should leave this option set to 'N'.
1724 string "Built-in kernel command string"
1725 depends on CMDLINE_BOOL
1728 Enter arguments here that should be compiled into the kernel
1729 image and used at boot time. If the boot loader provides a
1730 command line at boot time, it is appended to this string to
1731 form the full kernel command line, when the system boots.
1733 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1734 change this behavior.
1736 In most cases, the command line (whether built-in or provided
1737 by the boot loader) should specify the device for the root
1740 config CMDLINE_OVERRIDE
1741 bool "Built-in command line overrides boot loader arguments"
1742 depends on CMDLINE_BOOL
1744 Set this option to 'Y' to have the kernel ignore the boot loader
1745 command line, and use ONLY the built-in command line.
1747 This is used to work around broken boot loaders. This should
1748 be set to 'N' under normal conditions.
1752 config ARCH_ENABLE_MEMORY_HOTPLUG
1754 depends on X86_64 || (X86_32 && HIGHMEM)
1756 config ARCH_ENABLE_MEMORY_HOTREMOVE
1758 depends on MEMORY_HOTPLUG
1760 config USE_PERCPU_NUMA_NODE_ID
1764 menu "Power management and ACPI options"
1766 config ARCH_HIBERNATION_HEADER
1768 depends on X86_64 && HIBERNATION
1770 source "kernel/power/Kconfig"
1772 source "drivers/acpi/Kconfig"
1774 source "drivers/sfi/Kconfig"
1781 tristate "APM (Advanced Power Management) BIOS support"
1782 depends on X86_32 && PM_SLEEP
1784 APM is a BIOS specification for saving power using several different
1785 techniques. This is mostly useful for battery powered laptops with
1786 APM compliant BIOSes. If you say Y here, the system time will be
1787 reset after a RESUME operation, the /proc/apm device will provide
1788 battery status information, and user-space programs will receive
1789 notification of APM "events" (e.g. battery status change).
1791 If you select "Y" here, you can disable actual use of the APM
1792 BIOS by passing the "apm=off" option to the kernel at boot time.
1794 Note that the APM support is almost completely disabled for
1795 machines with more than one CPU.
1797 In order to use APM, you will need supporting software. For location
1798 and more information, read <file:Documentation/power/apm-acpi.txt>
1799 and the Battery Powered Linux mini-HOWTO, available from
1800 <http://www.tldp.org/docs.html#howto>.
1802 This driver does not spin down disk drives (see the hdparm(8)
1803 manpage ("man 8 hdparm") for that), and it doesn't turn off
1804 VESA-compliant "green" monitors.
1806 This driver does not support the TI 4000M TravelMate and the ACER
1807 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1808 desktop machines also don't have compliant BIOSes, and this driver
1809 may cause those machines to panic during the boot phase.
1811 Generally, if you don't have a battery in your machine, there isn't
1812 much point in using this driver and you should say N. If you get
1813 random kernel OOPSes or reboots that don't seem to be related to
1814 anything, try disabling/enabling this option (or disabling/enabling
1817 Some other things you should try when experiencing seemingly random,
1820 1) make sure that you have enough swap space and that it is
1822 2) pass the "no-hlt" option to the kernel
1823 3) switch on floating point emulation in the kernel and pass
1824 the "no387" option to the kernel
1825 4) pass the "floppy=nodma" option to the kernel
1826 5) pass the "mem=4M" option to the kernel (thereby disabling
1827 all but the first 4 MB of RAM)
1828 6) make sure that the CPU is not over clocked.
1829 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1830 8) disable the cache from your BIOS settings
1831 9) install a fan for the video card or exchange video RAM
1832 10) install a better fan for the CPU
1833 11) exchange RAM chips
1834 12) exchange the motherboard.
1836 To compile this driver as a module, choose M here: the
1837 module will be called apm.
1841 config APM_IGNORE_USER_SUSPEND
1842 bool "Ignore USER SUSPEND"
1844 This option will ignore USER SUSPEND requests. On machines with a
1845 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1846 series notebooks, it is necessary to say Y because of a BIOS bug.
1848 config APM_DO_ENABLE
1849 bool "Enable PM at boot time"
1851 Enable APM features at boot time. From page 36 of the APM BIOS
1852 specification: "When disabled, the APM BIOS does not automatically
1853 power manage devices, enter the Standby State, enter the Suspend
1854 State, or take power saving steps in response to CPU Idle calls."
1855 This driver will make CPU Idle calls when Linux is idle (unless this
1856 feature is turned off -- see "Do CPU IDLE calls", below). This
1857 should always save battery power, but more complicated APM features
1858 will be dependent on your BIOS implementation. You may need to turn
1859 this option off if your computer hangs at boot time when using APM
1860 support, or if it beeps continuously instead of suspending. Turn
1861 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1862 T400CDT. This is off by default since most machines do fine without
1866 bool "Make CPU Idle calls when idle"
1868 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1869 On some machines, this can activate improved power savings, such as
1870 a slowed CPU clock rate, when the machine is idle. These idle calls
1871 are made after the idle loop has run for some length of time (e.g.,
1872 333 mS). On some machines, this will cause a hang at boot time or
1873 whenever the CPU becomes idle. (On machines with more than one CPU,
1874 this option does nothing.)
1876 config APM_DISPLAY_BLANK
1877 bool "Enable console blanking using APM"
1879 Enable console blanking using the APM. Some laptops can use this to
1880 turn off the LCD backlight when the screen blanker of the Linux
1881 virtual console blanks the screen. Note that this is only used by
1882 the virtual console screen blanker, and won't turn off the backlight
1883 when using the X Window system. This also doesn't have anything to
1884 do with your VESA-compliant power-saving monitor. Further, this
1885 option doesn't work for all laptops -- it might not turn off your
1886 backlight at all, or it might print a lot of errors to the console,
1887 especially if you are using gpm.
1889 config APM_ALLOW_INTS
1890 bool "Allow interrupts during APM BIOS calls"
1892 Normally we disable external interrupts while we are making calls to
1893 the APM BIOS as a measure to lessen the effects of a badly behaving
1894 BIOS implementation. The BIOS should reenable interrupts if it
1895 needs to. Unfortunately, some BIOSes do not -- especially those in
1896 many of the newer IBM Thinkpads. If you experience hangs when you
1897 suspend, try setting this to Y. Otherwise, say N.
1901 source "drivers/cpufreq/Kconfig"
1903 source "drivers/cpuidle/Kconfig"
1905 source "drivers/idle/Kconfig"
1910 menu "Bus options (PCI etc.)"
1915 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1917 Find out whether you have a PCI motherboard. PCI is the name of a
1918 bus system, i.e. the way the CPU talks to the other stuff inside
1919 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1920 VESA. If you have PCI, say Y, otherwise N.
1923 prompt "PCI access mode"
1924 depends on X86_32 && PCI
1927 On PCI systems, the BIOS can be used to detect the PCI devices and
1928 determine their configuration. However, some old PCI motherboards
1929 have BIOS bugs and may crash if this is done. Also, some embedded
1930 PCI-based systems don't have any BIOS at all. Linux can also try to
1931 detect the PCI hardware directly without using the BIOS.
1933 With this option, you can specify how Linux should detect the
1934 PCI devices. If you choose "BIOS", the BIOS will be used,
1935 if you choose "Direct", the BIOS won't be used, and if you
1936 choose "MMConfig", then PCI Express MMCONFIG will be used.
1937 If you choose "Any", the kernel will try MMCONFIG, then the
1938 direct access method and falls back to the BIOS if that doesn't
1939 work. If unsure, go with the default, which is "Any".
1944 config PCI_GOMMCONFIG
1961 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1963 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1966 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1970 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1974 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1978 depends on PCI && XEN
1986 bool "Support mmconfig PCI config space access"
1987 depends on X86_64 && PCI && ACPI
1989 config PCI_CNB20LE_QUIRK
1990 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1991 depends on PCI && EXPERIMENTAL
1993 Read the PCI windows out of the CNB20LE host bridge. This allows
1994 PCI hotplug to work on systems with the CNB20LE chipset which do
1997 There's no public spec for this chipset, and this functionality
1998 is known to be incomplete.
2000 You should say N unless you know you need this.
2002 source "drivers/pci/pcie/Kconfig"
2004 source "drivers/pci/Kconfig"
2006 # x86_64 have no ISA slots, but can have ISA-style DMA.
2008 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2011 Enables ISA-style DMA support for devices requiring such controllers.
2019 Find out whether you have ISA slots on your motherboard. ISA is the
2020 name of a bus system, i.e. the way the CPU talks to the other stuff
2021 inside your box. Other bus systems are PCI, EISA, MicroChannel
2022 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2023 newer boards don't support it. If you have ISA, say Y, otherwise N.
2029 The Extended Industry Standard Architecture (EISA) bus was
2030 developed as an open alternative to the IBM MicroChannel bus.
2032 The EISA bus provided some of the features of the IBM MicroChannel
2033 bus while maintaining backward compatibility with cards made for
2034 the older ISA bus. The EISA bus saw limited use between 1988 and
2035 1995 when it was made obsolete by the PCI bus.
2037 Say Y here if you are building a kernel for an EISA-based machine.
2041 source "drivers/eisa/Kconfig"
2044 tristate "NatSemi SCx200 support"
2046 This provides basic support for National Semiconductor's
2047 (now AMD's) Geode processors. The driver probes for the
2048 PCI-IDs of several on-chip devices, so its a good dependency
2049 for other scx200_* drivers.
2051 If compiled as a module, the driver is named scx200.
2053 config SCx200HR_TIMER
2054 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2058 This driver provides a clocksource built upon the on-chip
2059 27MHz high-resolution timer. Its also a workaround for
2060 NSC Geode SC-1100's buggy TSC, which loses time when the
2061 processor goes idle (as is done by the scheduler). The
2062 other workaround is idle=poll boot option.
2065 bool "One Laptop Per Child support"
2072 Add support for detecting the unique features of the OLPC
2076 bool "OLPC XO-1 Power Management"
2077 depends on OLPC && MFD_CS5535 && PM_SLEEP
2080 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2083 bool "OLPC XO-1 Real Time Clock"
2084 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2086 Add support for the XO-1 real time clock, which can be used as a
2087 programmable wakeup source.
2090 bool "OLPC XO-1 SCI extras"
2091 depends on OLPC && OLPC_XO1_PM
2096 Add support for SCI-based features of the OLPC XO-1 laptop:
2097 - EC-driven system wakeups
2101 - AC adapter status updates
2102 - Battery status updates
2104 config OLPC_XO15_SCI
2105 bool "OLPC XO-1.5 SCI extras"
2106 depends on OLPC && ACPI
2109 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2110 - EC-driven system wakeups
2111 - AC adapter status updates
2112 - Battery status updates
2115 bool "PCEngines ALIX System Support (LED setup)"
2118 This option enables system support for the PCEngines ALIX.
2119 At present this just sets up LEDs for GPIO control on
2120 ALIX2/3/6 boards. However, other system specific setup should
2123 Note: You must still enable the drivers for GPIO and LED support
2124 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2126 Note: You have to set alix.force=1 for boards with Award BIOS.
2129 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2132 This option enables system support for the Soekris Engineering net5501.
2135 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2139 This option enables system support for the Traverse Technologies GEOS.
2145 depends on CPU_SUP_AMD && PCI
2147 source "drivers/pcmcia/Kconfig"
2149 source "drivers/pci/hotplug/Kconfig"
2152 bool "RapidIO support"
2156 If you say Y here, the kernel will include drivers and
2157 infrastructure code to support RapidIO interconnect devices.
2159 source "drivers/rapidio/Kconfig"
2164 menu "Executable file formats / Emulations"
2166 source "fs/Kconfig.binfmt"
2168 config IA32_EMULATION
2169 bool "IA32 Emulation"
2171 select COMPAT_BINFMT_ELF
2174 Include code to run legacy 32-bit programs under a
2175 64-bit kernel. You should likely turn this on, unless you're
2176 100% sure that you don't have any 32-bit programs left.
2179 tristate "IA32 a.out support"
2180 depends on IA32_EMULATION
2182 Support old a.out binaries in the 32bit emulation.
2185 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2186 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2188 Include code to run binaries for the x32 native 32-bit ABI
2189 for 64-bit processors. An x32 process gets access to the
2190 full 64-bit register file and wide data path while leaving
2191 pointers at 32 bits for smaller memory footprint.
2193 You will need a recent binutils (2.22 or later) with
2194 elf32_x86_64 support enabled to compile a kernel with this
2199 depends on IA32_EMULATION || X86_X32
2200 select ARCH_WANT_OLD_COMPAT_IPC
2203 config COMPAT_FOR_U64_ALIGNMENT
2206 config SYSVIPC_COMPAT
2218 config HAVE_ATOMIC_IOMAP
2222 config HAVE_TEXT_POKE_SMP
2224 select STOP_MACHINE if SMP
2226 config X86_DEV_DMA_OPS
2228 depends on X86_64 || STA2X11
2230 config X86_DMA_REMAP
2234 source "net/Kconfig"
2236 source "drivers/Kconfig"
2238 source "drivers/firmware/Kconfig"
2242 source "arch/x86/Kconfig.debug"
2244 source "security/Kconfig"
2246 source "crypto/Kconfig"
2248 source "arch/x86/kvm/Kconfig"
2250 source "lib/Kconfig"