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
17 select X86_DEV_DMA_OPS
22 select HAVE_AOUT if X86_32
23 select HAVE_UNSTABLE_SCHED_CLOCK
26 select HAVE_PCSPKR_PLATFORM
27 select HAVE_PERF_EVENTS
29 select HAVE_IOREMAP_PROT
32 select HAVE_MEMBLOCK_NODE_MAP
33 select ARCH_DISCARD_MEMBLOCK
34 select ARCH_WANT_OPTIONAL_GPIOLIB
35 select ARCH_WANT_FRAME_POINTERS
37 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
38 select HAVE_KRETPROBES
40 select HAVE_FTRACE_MCOUNT_RECORD
41 select HAVE_FENTRY if X86_64
42 select HAVE_C_RECORDMCOUNT
43 select HAVE_DYNAMIC_FTRACE
44 select HAVE_FUNCTION_TRACER
45 select HAVE_FUNCTION_GRAPH_TRACER
46 select HAVE_FUNCTION_GRAPH_FP_TEST
47 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
48 select HAVE_SYSCALL_TRACEPOINTS
51 select HAVE_ARCH_TRACEHOOK
52 select HAVE_GENERIC_DMA_COHERENT if X86_32
53 select HAVE_EFFICIENT_UNALIGNED_ACCESS
54 select USER_STACKTRACE_SUPPORT
55 select HAVE_REGS_AND_STACK_ACCESS_API
56 select HAVE_DMA_API_DEBUG
57 select HAVE_KERNEL_GZIP
58 select HAVE_KERNEL_BZIP2
59 select HAVE_KERNEL_LZMA
61 select HAVE_KERNEL_LZO
62 select HAVE_HW_BREAKPOINT
63 select HAVE_MIXED_BREAKPOINTS_REGS
65 select HAVE_PERF_EVENTS_NMI
67 select HAVE_PERF_USER_STACK_DUMP
69 select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386
70 select HAVE_CMPXCHG_LOCAL if !M386
71 select HAVE_CMPXCHG_DOUBLE
72 select HAVE_ARCH_KMEMCHECK
73 select HAVE_USER_RETURN_NOTIFIER
74 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
75 select HAVE_ARCH_JUMP_LABEL
76 select HAVE_TEXT_POKE_SMP
77 select HAVE_GENERIC_HARDIRQS
78 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
80 select GENERIC_FIND_FIRST_BIT
81 select GENERIC_IRQ_PROBE
82 select GENERIC_PENDING_IRQ if SMP
83 select GENERIC_IRQ_SHOW
84 select GENERIC_CLOCKEVENTS_MIN_ADJUST
85 select IRQ_FORCED_THREADING
86 select USE_GENERIC_SMP_HELPERS if SMP
87 select HAVE_BPF_JIT if X86_64
89 select ARCH_HAVE_NMI_SAFE_CMPXCHG
91 select DCACHE_WORD_ACCESS
92 select GENERIC_SMP_IDLE_THREAD
93 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
94 select HAVE_ARCH_SECCOMP_FILTER
95 select BUILDTIME_EXTABLE_SORT
96 select GENERIC_CMOS_UPDATE
97 select CLOCKSOURCE_WATCHDOG
98 select GENERIC_CLOCKEVENTS
99 select ARCH_CLOCKSOURCE_DATA if X86_64
100 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
101 select GENERIC_TIME_VSYSCALL if X86_64
102 select KTIME_SCALAR if X86_32
103 select GENERIC_STRNCPY_FROM_USER
104 select GENERIC_STRNLEN_USER
105 select HAVE_RCU_USER_QS if X86_64
106 select HAVE_IRQ_TIME_ACCOUNTING
108 config INSTRUCTION_DECODER
110 depends on KPROBES || PERF_EVENTS || UPROBES
114 default "elf32-i386" if X86_32
115 default "elf64-x86-64" if X86_64
117 config ARCH_DEFCONFIG
119 default "arch/x86/configs/i386_defconfig" if X86_32
120 default "arch/x86/configs/x86_64_defconfig" if X86_64
122 config LOCKDEP_SUPPORT
125 config STACKTRACE_SUPPORT
128 config HAVE_LATENCYTOP_SUPPORT
137 config NEED_DMA_MAP_STATE
139 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
141 config NEED_SG_DMA_LENGTH
144 config GENERIC_ISA_DMA
146 depends on ISA_DMA_API
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
164 depends on ISA_DMA_API
166 config RWSEM_GENERIC_SPINLOCK
170 config RWSEM_XCHGADD_ALGORITHM
174 config GENERIC_CALIBRATE_DELAY
177 config ARCH_HAS_CPU_RELAX
180 config ARCH_HAS_DEFAULT_IDLE
183 config ARCH_HAS_CACHE_LINE_SIZE
186 config ARCH_HAS_CPU_AUTOPROBE
189 config HAVE_SETUP_PER_CPU_AREA
192 config NEED_PER_CPU_EMBED_FIRST_CHUNK
195 config NEED_PER_CPU_PAGE_FIRST_CHUNK
198 config ARCH_HIBERNATION_POSSIBLE
201 config ARCH_SUSPEND_POSSIBLE
212 config ARCH_SUPPORTS_OPTIMIZED_INLINING
215 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
218 config HAVE_INTEL_TXT
220 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
224 depends on X86_32 && SMP
228 depends on X86_64 && SMP
234 config X86_32_LAZY_GS
236 depends on X86_32 && !CC_STACKPROTECTOR
238 config ARCH_HWEIGHT_CFLAGS
240 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
241 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
243 config ARCH_CPU_PROBE_RELEASE
245 depends on HOTPLUG_CPU
247 config ARCH_SUPPORTS_UPROBES
250 source "init/Kconfig"
251 source "kernel/Kconfig.freezer"
253 menu "Processor type and features"
256 bool "DMA memory allocation support" if EXPERT
259 DMA memory allocation support allows devices with less than 32-bit
260 addressing to allocate within the first 16MB of address space.
261 Disable if no such devices will be used.
266 bool "Symmetric multi-processing support"
268 This enables support for systems with more than one CPU. If you have
269 a system with only one CPU, like most personal computers, say N. If
270 you have a system with more than one CPU, say Y.
272 If you say N here, the kernel will run on single and multiprocessor
273 machines, but will use only one CPU of a multiprocessor machine. If
274 you say Y here, the kernel will run on many, but not all,
275 singleprocessor machines. On a singleprocessor machine, the kernel
276 will run faster if you say N here.
278 Note that if you say Y here and choose architecture "586" or
279 "Pentium" under "Processor family", the kernel will not work on 486
280 architectures. Similarly, multiprocessor kernels for the "PPro"
281 architecture may not work on all Pentium based boards.
283 People using multiprocessor machines who say Y here should also say
284 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
285 Management" code will be disabled if you say Y here.
287 See also <file:Documentation/x86/i386/IO-APIC.txt>,
288 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
289 <http://www.tldp.org/docs.html#howto>.
291 If you don't know what to do here, say N.
294 bool "Support x2apic"
295 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
297 This enables x2apic support on CPUs that have this feature.
299 This allows 32-bit apic IDs (so it can support very large systems),
300 and accesses the local apic via MSRs not via mmio.
302 If you don't know what to do here, say N.
305 bool "Enable MPS table" if ACPI
307 depends on X86_LOCAL_APIC
309 For old smp systems that do not have proper acpi support. Newer systems
310 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
313 bool "Support for big SMP systems with more than 8 CPUs"
314 depends on X86_32 && SMP
316 This option is needed for the systems that have more than 8 CPUs
319 config X86_EXTENDED_PLATFORM
320 bool "Support for extended (non-PC) x86 platforms"
323 If you disable this option then the kernel will only support
324 standard PC platforms. (which covers the vast majority of
327 If you enable this option then you'll be able to select support
328 for the following (non-PC) 32 bit x86 platforms:
332 SGI 320/540 (Visual Workstation)
333 STA2X11-based (e.g. Northville)
334 Summit/EXA (IBM x440)
335 Unisys ES7000 IA32 series
336 Moorestown MID devices
338 If you have one of these systems, or if you want to build a
339 generic distribution kernel, say Y here - otherwise say N.
343 config X86_EXTENDED_PLATFORM
344 bool "Support for extended (non-PC) x86 platforms"
347 If you disable this option then the kernel will only support
348 standard PC platforms. (which covers the vast majority of
351 If you enable this option then you'll be able to select support
352 for the following (non-PC) 64 bit x86 platforms:
357 If you have one of these systems, or if you want to build a
358 generic distribution kernel, say Y here - otherwise say N.
360 # This is an alphabetically sorted list of 64 bit extended platforms
361 # Please maintain the alphabetic order if and when there are additions
363 bool "Numascale NumaChip"
365 depends on X86_EXTENDED_PLATFORM
368 depends on X86_X2APIC
370 Adds support for Numascale NumaChip large-SMP systems. Needed to
371 enable more than ~168 cores.
372 If you don't have one of these, you should say N here.
376 select PARAVIRT_GUEST
378 depends on X86_64 && PCI
379 depends on X86_EXTENDED_PLATFORM
382 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
383 supposed to run on these EM64T-based machines. Only choose this option
384 if you have one of these machines.
387 bool "SGI Ultraviolet"
389 depends on X86_EXTENDED_PLATFORM
391 depends on X86_X2APIC
393 This option is needed in order to support SGI Ultraviolet systems.
394 If you don't have one of these, you should say N here.
396 # Following is an alphabetically sorted list of 32 bit extended platforms
397 # Please maintain the alphabetic order if and when there are additions
400 bool "CE4100 TV platform"
402 depends on PCI_GODIRECT
404 depends on X86_EXTENDED_PLATFORM
405 select X86_REBOOTFIXUPS
407 select OF_EARLY_FLATTREE
410 Select for the Intel CE media processor (CE4100) SOC.
411 This option compiles in support for the CE4100 SOC for settop
412 boxes and media devices.
414 config X86_WANT_INTEL_MID
415 bool "Intel MID platform support"
417 depends on X86_EXTENDED_PLATFORM
419 Select to build a kernel capable of supporting Intel MID platform
420 systems which do not have the PCI legacy interfaces (Moorestown,
421 Medfield). If you are building for a PC class system say N here.
423 if X86_WANT_INTEL_MID
429 bool "Medfield MID platform"
432 depends on X86_IO_APIC
440 select X86_PLATFORM_DEVICES
441 select MFD_INTEL_MSIC
443 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
444 Internet Device(MID) platform.
445 Unlike standard x86 PCs, Medfield does not have many legacy devices
446 nor standard legacy replacement devices/features. e.g. Medfield does
447 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
452 bool "RDC R-321x SoC"
454 depends on X86_EXTENDED_PLATFORM
456 select X86_REBOOTFIXUPS
458 This option is needed for RDC R-321x system-on-chip, also known
460 If you don't have one of these chips, you should say N here.
462 config X86_32_NON_STANDARD
463 bool "Support non-standard 32-bit SMP architectures"
464 depends on X86_32 && SMP
465 depends on X86_EXTENDED_PLATFORM
467 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
468 STA2X11, default subarchitectures. It is intended for a generic
469 binary kernel. If you select them all, kernel will probe it
470 one by one and will fallback to default.
472 # Alphabetically sorted list of Non standard 32 bit platforms
475 bool "NUMAQ (IBM/Sequent)"
476 depends on X86_32_NON_STANDARD
481 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
482 NUMA multiquad box. This changes the way that processors are
483 bootstrapped, and uses Clustered Logical APIC addressing mode instead
484 of Flat Logical. You will need a new lynxer.elf file to flash your
485 firmware with - send email to <Martin.Bligh@us.ibm.com>.
487 config X86_SUPPORTS_MEMORY_FAILURE
489 # MCE code calls memory_failure():
491 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
492 depends on !X86_NUMAQ
493 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
494 depends on X86_64 || !SPARSEMEM
495 select ARCH_SUPPORTS_MEMORY_FAILURE
498 bool "SGI 320/540 (Visual Workstation)"
499 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
500 depends on X86_32_NON_STANDARD
502 The SGI Visual Workstation series is an IA32-based workstation
503 based on SGI systems chips with some legacy PC hardware attached.
505 Say Y here to create a kernel to run on the SGI 320 or 540.
507 A kernel compiled for the Visual Workstation will run on general
508 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
511 bool "STA2X11 Companion Chip Support"
512 depends on X86_32_NON_STANDARD && PCI
513 select X86_DEV_DMA_OPS
517 select ARCH_REQUIRE_GPIOLIB
520 This adds support for boards based on the STA2X11 IO-Hub,
521 a.k.a. "ConneXt". The chip is used in place of the standard
522 PC chipset, so all "standard" peripherals are missing. If this
523 option is selected the kernel will still be able to boot on
524 standard PC machines.
527 bool "Summit/EXA (IBM x440)"
528 depends on X86_32_NON_STANDARD
530 This option is needed for IBM systems that use the Summit/EXA chipset.
531 In particular, it is needed for the x440.
534 bool "Unisys ES7000 IA32 series"
535 depends on X86_32_NON_STANDARD && X86_BIGSMP
537 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
538 supposed to run on an IA32-based Unisys ES7000 system.
541 tristate "Eurobraille/Iris poweroff module"
544 The Iris machines from EuroBraille do not have APM or ACPI support
545 to shut themselves down properly. A special I/O sequence is
546 needed to do so, which is what this module does at
549 This is only for Iris machines from EuroBraille.
553 config SCHED_OMIT_FRAME_POINTER
555 prompt "Single-depth WCHAN output"
558 Calculate simpler /proc/<PID>/wchan values. If this option
559 is disabled then wchan values will recurse back to the
560 caller function. This provides more accurate wchan values,
561 at the expense of slightly more scheduling overhead.
563 If in doubt, say "Y".
565 menuconfig PARAVIRT_GUEST
566 bool "Paravirtualized guest support"
568 Say Y here to get to see options related to running Linux under
569 various hypervisors. This option alone does not add any kernel code.
571 If you say N, all options in this submenu will be skipped and disabled.
575 config PARAVIRT_TIME_ACCOUNTING
576 bool "Paravirtual steal time accounting"
580 Select this option to enable fine granularity task steal time
581 accounting. Time spent executing other tasks in parallel with
582 the current vCPU is discounted from the vCPU power. To account for
583 that, there can be a small performance impact.
585 If in doubt, say N here.
587 source "arch/x86/xen/Kconfig"
590 bool "KVM Guest support (including kvmclock)"
593 select PARAVIRT_CLOCK
594 default y if PARAVIRT_GUEST
596 This option enables various optimizations for running under the KVM
597 hypervisor. It includes a paravirtualized clock, so that instead
598 of relying on a PIT (or probably other) emulation by the
599 underlying device model, the host provides the guest with
600 timing infrastructure such as time of day, and system time
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. Using this PCI devices
758 which can only access 32-bits of memory can be used on systems
759 with more than 3 GB of memory.
764 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
767 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
768 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
769 select CPUMASK_OFFSTACK
771 Enable maximum number of CPUS and NUMA Nodes for this architecture.
775 int "Maximum number of CPUs" if SMP && !MAXSMP
776 range 2 8 if SMP && X86_32 && !X86_BIGSMP
777 range 2 512 if SMP && !MAXSMP
779 default "4096" if MAXSMP
780 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
783 This allows you to specify the maximum number of CPUs which this
784 kernel will support. The maximum supported value is 512 and the
785 minimum value which makes sense is 2.
787 This is purely to save memory - each supported CPU adds
788 approximately eight kilobytes to the kernel image.
791 bool "SMT (Hyperthreading) scheduler support"
794 SMT scheduler support improves the CPU scheduler's decision making
795 when dealing with Intel Pentium 4 chips with HyperThreading at a
796 cost of slightly increased overhead in some places. If unsure say
801 prompt "Multi-core scheduler support"
804 Multi-core scheduler support improves the CPU scheduler's decision
805 making when dealing with multi-core CPU chips at a cost of slightly
806 increased overhead in some places. If unsure say N here.
808 source "kernel/Kconfig.preempt"
811 bool "Local APIC support on uniprocessors"
812 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
814 A local APIC (Advanced Programmable Interrupt Controller) is an
815 integrated interrupt controller in the CPU. If you have a single-CPU
816 system which has a processor with a local APIC, you can say Y here to
817 enable and use it. If you say Y here even though your machine doesn't
818 have a local APIC, then the kernel will still run with no slowdown at
819 all. The local APIC supports CPU-generated self-interrupts (timer,
820 performance counters), and the NMI watchdog which detects hard
824 bool "IO-APIC support on uniprocessors"
825 depends on X86_UP_APIC
827 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
828 SMP-capable replacement for PC-style interrupt controllers. Most
829 SMP systems and many recent uniprocessor systems have one.
831 If you have a single-CPU system with an IO-APIC, you can say Y here
832 to use it. If you say Y here even though your machine doesn't have
833 an IO-APIC, then the kernel will still run with no slowdown at all.
835 config X86_LOCAL_APIC
837 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
841 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
843 config X86_VISWS_APIC
845 depends on X86_32 && X86_VISWS
847 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
848 bool "Reroute for broken boot IRQs"
849 depends on X86_IO_APIC
851 This option enables a workaround that fixes a source of
852 spurious interrupts. This is recommended when threaded
853 interrupt handling is used on systems where the generation of
854 superfluous "boot interrupts" cannot be disabled.
856 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
857 entry in the chipset's IO-APIC is masked (as, e.g. the RT
858 kernel does during interrupt handling). On chipsets where this
859 boot IRQ generation cannot be disabled, this workaround keeps
860 the original IRQ line masked so that only the equivalent "boot
861 IRQ" is delivered to the CPUs. The workaround also tells the
862 kernel to set up the IRQ handler on the boot IRQ line. In this
863 way only one interrupt is delivered to the kernel. Otherwise
864 the spurious second interrupt may cause the kernel to bring
865 down (vital) interrupt lines.
867 Only affects "broken" chipsets. Interrupt sharing may be
868 increased on these systems.
871 bool "Machine Check / overheating reporting"
874 Machine Check support allows the processor to notify the
875 kernel if it detects a problem (e.g. overheating, data corruption).
876 The action the kernel takes depends on the severity of the problem,
877 ranging from warning messages to halting the machine.
881 prompt "Intel MCE features"
882 depends on X86_MCE && X86_LOCAL_APIC
884 Additional support for intel specific MCE features such as
889 prompt "AMD MCE features"
890 depends on X86_MCE && X86_LOCAL_APIC
892 Additional support for AMD specific MCE features such as
893 the DRAM Error Threshold.
895 config X86_ANCIENT_MCE
896 bool "Support for old Pentium 5 / WinChip machine checks"
897 depends on X86_32 && X86_MCE
899 Include support for machine check handling on old Pentium 5 or WinChip
900 systems. These typically need to be enabled explicitely on the command
903 config X86_MCE_THRESHOLD
904 depends on X86_MCE_AMD || X86_MCE_INTEL
907 config X86_MCE_INJECT
909 tristate "Machine check injector support"
911 Provide support for injecting machine checks for testing purposes.
912 If you don't know what a machine check is and you don't do kernel
913 QA it is safe to say n.
915 config X86_THERMAL_VECTOR
917 depends on X86_MCE_INTEL
920 bool "Enable VM86 support" if EXPERT
924 This option is required by programs like DOSEMU to run 16-bit legacy
925 code on X86 processors. It also may be needed by software like
926 XFree86 to initialize some video cards via BIOS. Disabling this
927 option saves about 6k.
930 tristate "Toshiba Laptop support"
933 This adds a driver to safely access the System Management Mode of
934 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
935 not work on models with a Phoenix BIOS. The System Management Mode
936 is used to set the BIOS and power saving options on Toshiba portables.
938 For information on utilities to make use of this driver see the
939 Toshiba Linux utilities web site at:
940 <http://www.buzzard.org.uk/toshiba/>.
942 Say Y if you intend to run this kernel on a Toshiba portable.
946 tristate "Dell laptop support"
949 This adds a driver to safely access the System Management Mode
950 of the CPU on the Dell Inspiron 8000. The System Management Mode
951 is used to read cpu temperature and cooling fan status and to
952 control the fans on the I8K portables.
954 This driver has been tested only on the Inspiron 8000 but it may
955 also work with other Dell laptops. You can force loading on other
956 models by passing the parameter `force=1' to the module. Use at
959 For information on utilities to make use of this driver see the
960 I8K Linux utilities web site at:
961 <http://people.debian.org/~dz/i8k/>
963 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
966 config X86_REBOOTFIXUPS
967 bool "Enable X86 board specific fixups for reboot"
970 This enables chipset and/or board specific fixups to be done
971 in order to get reboot to work correctly. This is only needed on
972 some combinations of hardware and BIOS. The symptom, for which
973 this config is intended, is when reboot ends with a stalled/hung
976 Currently, the only fixup is for the Geode machines using
977 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
979 Say Y if you want to enable the fixup. Currently, it's safe to
980 enable this option even if you don't need it.
984 tristate "CPU microcode loading support"
988 If you say Y here, you will be able to update the microcode on
989 certain Intel and AMD processors. The Intel support is for the
990 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
991 Xeon etc. The AMD support is for families 0x10 and later. You will
992 obviously need the actual microcode binary data itself which is not
993 shipped with the Linux kernel.
995 This option selects the general module only, you need to select
996 at least one vendor specific module as well.
998 To compile this driver as a module, choose M here: the module
999 will be called microcode.
1001 config MICROCODE_INTEL
1002 bool "Intel microcode loading support"
1003 depends on MICROCODE
1007 This options enables microcode patch loading support for Intel
1010 For latest news and information on obtaining all the required
1011 Intel ingredients for this driver, check:
1012 <http://www.urbanmyth.org/microcode/>.
1014 config MICROCODE_AMD
1015 bool "AMD microcode loading support"
1016 depends on MICROCODE
1019 If you select this option, microcode patch loading support for AMD
1020 processors will be enabled.
1022 config MICROCODE_OLD_INTERFACE
1024 depends on MICROCODE
1027 tristate "/dev/cpu/*/msr - Model-specific register support"
1029 This device gives privileged processes access to the x86
1030 Model-Specific Registers (MSRs). It is a character device with
1031 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1032 MSR accesses are directed to a specific CPU on multi-processor
1036 tristate "/dev/cpu/*/cpuid - CPU information support"
1038 This device gives processes access to the x86 CPUID instruction to
1039 be executed on a specific processor. It is a character device
1040 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1044 prompt "High Memory Support"
1045 default HIGHMEM64G if X86_NUMAQ
1051 depends on !X86_NUMAQ
1053 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1054 However, the address space of 32-bit x86 processors is only 4
1055 Gigabytes large. That means that, if you have a large amount of
1056 physical memory, not all of it can be "permanently mapped" by the
1057 kernel. The physical memory that's not permanently mapped is called
1060 If you are compiling a kernel which will never run on a machine with
1061 more than 1 Gigabyte total physical RAM, answer "off" here (default
1062 choice and suitable for most users). This will result in a "3GB/1GB"
1063 split: 3GB are mapped so that each process sees a 3GB virtual memory
1064 space and the remaining part of the 4GB virtual memory space is used
1065 by the kernel to permanently map as much physical memory as
1068 If the machine has between 1 and 4 Gigabytes physical RAM, then
1071 If more than 4 Gigabytes is used then answer "64GB" here. This
1072 selection turns Intel PAE (Physical Address Extension) mode on.
1073 PAE implements 3-level paging on IA32 processors. PAE is fully
1074 supported by Linux, PAE mode is implemented on all recent Intel
1075 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1076 then the kernel will not boot on CPUs that don't support PAE!
1078 The actual amount of total physical memory will either be
1079 auto detected or can be forced by using a kernel command line option
1080 such as "mem=256M". (Try "man bootparam" or see the documentation of
1081 your boot loader (lilo or loadlin) about how to pass options to the
1082 kernel at boot time.)
1084 If unsure, say "off".
1088 depends on !X86_NUMAQ
1090 Select this if you have a 32-bit processor and between 1 and 4
1091 gigabytes of physical RAM.
1095 depends on !M386 && !M486
1098 Select this if you have a 32-bit processor and more than 4
1099 gigabytes of physical RAM.
1104 depends on EXPERIMENTAL
1105 prompt "Memory split" if EXPERT
1109 Select the desired split between kernel and user memory.
1111 If the address range available to the kernel is less than the
1112 physical memory installed, the remaining memory will be available
1113 as "high memory". Accessing high memory is a little more costly
1114 than low memory, as it needs to be mapped into the kernel first.
1115 Note that increasing the kernel address space limits the range
1116 available to user programs, making the address space there
1117 tighter. Selecting anything other than the default 3G/1G split
1118 will also likely make your kernel incompatible with binary-only
1121 If you are not absolutely sure what you are doing, leave this
1125 bool "3G/1G user/kernel split"
1126 config VMSPLIT_3G_OPT
1128 bool "3G/1G user/kernel split (for full 1G low memory)"
1130 bool "2G/2G user/kernel split"
1131 config VMSPLIT_2G_OPT
1133 bool "2G/2G user/kernel split (for full 2G low memory)"
1135 bool "1G/3G user/kernel split"
1140 default 0xB0000000 if VMSPLIT_3G_OPT
1141 default 0x80000000 if VMSPLIT_2G
1142 default 0x78000000 if VMSPLIT_2G_OPT
1143 default 0x40000000 if VMSPLIT_1G
1149 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1152 bool "PAE (Physical Address Extension) Support"
1153 depends on X86_32 && !HIGHMEM4G
1155 PAE is required for NX support, and furthermore enables
1156 larger swapspace support for non-overcommit purposes. It
1157 has the cost of more pagetable lookup overhead, and also
1158 consumes more pagetable space per process.
1160 config ARCH_PHYS_ADDR_T_64BIT
1162 depends on X86_64 || X86_PAE
1164 config ARCH_DMA_ADDR_T_64BIT
1166 depends on X86_64 || HIGHMEM64G
1168 config DIRECT_GBPAGES
1169 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1173 Allow the kernel linear mapping to use 1GB pages on CPUs that
1174 support it. This can improve the kernel's performance a tiny bit by
1175 reducing TLB pressure. If in doubt, say "Y".
1177 # Common NUMA Features
1179 bool "Numa Memory Allocation and Scheduler Support"
1181 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1182 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1184 Enable NUMA (Non Uniform Memory Access) support.
1186 The kernel will try to allocate memory used by a CPU on the
1187 local memory controller of the CPU and add some more
1188 NUMA awareness to the kernel.
1190 For 64-bit this is recommended if the system is Intel Core i7
1191 (or later), AMD Opteron, or EM64T NUMA.
1193 For 32-bit this is only needed on (rare) 32-bit-only platforms
1194 that support NUMA topologies, such as NUMAQ / Summit, or if you
1195 boot a 32-bit kernel on a 64-bit NUMA platform.
1197 Otherwise, you should say N.
1199 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1200 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1204 prompt "Old style AMD Opteron NUMA detection"
1205 depends on X86_64 && NUMA && PCI
1207 Enable AMD NUMA node topology detection. You should say Y here if
1208 you have a multi processor AMD system. This uses an old method to
1209 read the NUMA configuration directly from the builtin Northbridge
1210 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1211 which also takes priority if both are compiled in.
1213 config X86_64_ACPI_NUMA
1215 prompt "ACPI NUMA detection"
1216 depends on X86_64 && NUMA && ACPI && PCI
1219 Enable ACPI SRAT based node topology detection.
1221 # Some NUMA nodes have memory ranges that span
1222 # other nodes. Even though a pfn is valid and
1223 # between a node's start and end pfns, it may not
1224 # reside on that node. See memmap_init_zone()
1226 config NODES_SPAN_OTHER_NODES
1228 depends on X86_64_ACPI_NUMA
1231 bool "NUMA emulation"
1234 Enable NUMA emulation. A flat machine will be split
1235 into virtual nodes when booted with "numa=fake=N", where N is the
1236 number of nodes. This is only useful for debugging.
1239 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1241 default "10" if MAXSMP
1242 default "6" if X86_64
1243 default "4" if X86_NUMAQ
1245 depends on NEED_MULTIPLE_NODES
1247 Specify the maximum number of NUMA Nodes available on the target
1248 system. Increases memory reserved to accommodate various tables.
1250 config HAVE_ARCH_ALLOC_REMAP
1252 depends on X86_32 && NUMA
1254 config ARCH_HAVE_MEMORY_PRESENT
1256 depends on X86_32 && DISCONTIGMEM
1258 config NEED_NODE_MEMMAP_SIZE
1260 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1262 config ARCH_FLATMEM_ENABLE
1264 depends on X86_32 && !NUMA
1266 config ARCH_DISCONTIGMEM_ENABLE
1268 depends on NUMA && X86_32
1270 config ARCH_DISCONTIGMEM_DEFAULT
1272 depends on NUMA && X86_32
1274 config ARCH_SPARSEMEM_ENABLE
1276 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1277 select SPARSEMEM_STATIC if X86_32
1278 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1280 config ARCH_SPARSEMEM_DEFAULT
1284 config ARCH_SELECT_MEMORY_MODEL
1286 depends on ARCH_SPARSEMEM_ENABLE
1288 config ARCH_MEMORY_PROBE
1290 depends on X86_64 && MEMORY_HOTPLUG
1292 config ARCH_PROC_KCORE_TEXT
1294 depends on X86_64 && PROC_KCORE
1296 config ILLEGAL_POINTER_VALUE
1299 default 0xdead000000000000 if X86_64
1304 bool "Allocate 3rd-level pagetables from highmem"
1307 The VM uses one page table entry for each page of physical memory.
1308 For systems with a lot of RAM, this can be wasteful of precious
1309 low memory. Setting this option will put user-space page table
1310 entries in high memory.
1312 config X86_CHECK_BIOS_CORRUPTION
1313 bool "Check for low memory corruption"
1315 Periodically check for memory corruption in low memory, which
1316 is suspected to be caused by BIOS. Even when enabled in the
1317 configuration, it is disabled at runtime. Enable it by
1318 setting "memory_corruption_check=1" on the kernel command
1319 line. By default it scans the low 64k of memory every 60
1320 seconds; see the memory_corruption_check_size and
1321 memory_corruption_check_period parameters in
1322 Documentation/kernel-parameters.txt to adjust this.
1324 When enabled with the default parameters, this option has
1325 almost no overhead, as it reserves a relatively small amount
1326 of memory and scans it infrequently. It both detects corruption
1327 and prevents it from affecting the running system.
1329 It is, however, intended as a diagnostic tool; if repeatable
1330 BIOS-originated corruption always affects the same memory,
1331 you can use memmap= to prevent the kernel from using that
1334 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1335 bool "Set the default setting of memory_corruption_check"
1336 depends on X86_CHECK_BIOS_CORRUPTION
1339 Set whether the default state of memory_corruption_check is
1342 config X86_RESERVE_LOW
1343 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1347 Specify the amount of low memory to reserve for the BIOS.
1349 The first page contains BIOS data structures that the kernel
1350 must not use, so that page must always be reserved.
1352 By default we reserve the first 64K of physical RAM, as a
1353 number of BIOSes are known to corrupt that memory range
1354 during events such as suspend/resume or monitor cable
1355 insertion, so it must not be used by the kernel.
1357 You can set this to 4 if you are absolutely sure that you
1358 trust the BIOS to get all its memory reservations and usages
1359 right. If you know your BIOS have problems beyond the
1360 default 64K area, you can set this to 640 to avoid using the
1361 entire low memory range.
1363 If you have doubts about the BIOS (e.g. suspend/resume does
1364 not work or there's kernel crashes after certain hardware
1365 hotplug events) then you might want to enable
1366 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1367 typical corruption patterns.
1369 Leave this to the default value of 64 if you are unsure.
1371 config MATH_EMULATION
1373 prompt "Math emulation" if X86_32
1375 Linux can emulate a math coprocessor (used for floating point
1376 operations) if you don't have one. 486DX and Pentium processors have
1377 a math coprocessor built in, 486SX and 386 do not, unless you added
1378 a 487DX or 387, respectively. (The messages during boot time can
1379 give you some hints here ["man dmesg"].) Everyone needs either a
1380 coprocessor or this emulation.
1382 If you don't have a math coprocessor, you need to say Y here; if you
1383 say Y here even though you have a coprocessor, the coprocessor will
1384 be used nevertheless. (This behavior can be changed with the kernel
1385 command line option "no387", which comes handy if your coprocessor
1386 is broken. Try "man bootparam" or see the documentation of your boot
1387 loader (lilo or loadlin) about how to pass options to the kernel at
1388 boot time.) This means that it is a good idea to say Y here if you
1389 intend to use this kernel on different machines.
1391 More information about the internals of the Linux math coprocessor
1392 emulation can be found in <file:arch/x86/math-emu/README>.
1394 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1395 kernel, it won't hurt.
1399 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1401 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1402 the Memory Type Range Registers (MTRRs) may be used to control
1403 processor access to memory ranges. This is most useful if you have
1404 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1405 allows bus write transfers to be combined into a larger transfer
1406 before bursting over the PCI/AGP bus. This can increase performance
1407 of image write operations 2.5 times or more. Saying Y here creates a
1408 /proc/mtrr file which may be used to manipulate your processor's
1409 MTRRs. Typically the X server should use this.
1411 This code has a reasonably generic interface so that similar
1412 control registers on other processors can be easily supported
1415 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1416 Registers (ARRs) which provide a similar functionality to MTRRs. For
1417 these, the ARRs are used to emulate the MTRRs.
1418 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1419 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1420 write-combining. All of these processors are supported by this code
1421 and it makes sense to say Y here if you have one of them.
1423 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1424 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1425 can lead to all sorts of problems, so it's good to say Y here.
1427 You can safely say Y even if your machine doesn't have MTRRs, you'll
1428 just add about 9 KB to your kernel.
1430 See <file:Documentation/x86/mtrr.txt> for more information.
1432 config MTRR_SANITIZER
1434 prompt "MTRR cleanup support"
1437 Convert MTRR layout from continuous to discrete, so X drivers can
1438 add writeback entries.
1440 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1441 The largest mtrr entry size for a continuous block can be set with
1446 config MTRR_SANITIZER_ENABLE_DEFAULT
1447 int "MTRR cleanup enable value (0-1)"
1450 depends on MTRR_SANITIZER
1452 Enable mtrr cleanup default value
1454 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1455 int "MTRR cleanup spare reg num (0-7)"
1458 depends on MTRR_SANITIZER
1460 mtrr cleanup spare entries default, it can be changed via
1461 mtrr_spare_reg_nr=N on the kernel command line.
1465 prompt "x86 PAT support" if EXPERT
1468 Use PAT attributes to setup page level cache control.
1470 PATs are the modern equivalents of MTRRs and are much more
1471 flexible than MTRRs.
1473 Say N here if you see bootup problems (boot crash, boot hang,
1474 spontaneous reboots) or a non-working video driver.
1478 config ARCH_USES_PG_UNCACHED
1484 prompt "x86 architectural random number generator" if EXPERT
1486 Enable the x86 architectural RDRAND instruction
1487 (Intel Bull Mountain technology) to generate random numbers.
1488 If supported, this is a high bandwidth, cryptographically
1489 secure hardware random number generator.
1493 prompt "Supervisor Mode Access Prevention" if EXPERT
1495 Supervisor Mode Access Prevention (SMAP) is a security
1496 feature in newer Intel processors. There is a small
1497 performance cost if this enabled and turned on; there is
1498 also a small increase in the kernel size if this is enabled.
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.
1523 See Documentation/x86/efi-stub.txt for more information.
1527 prompt "Enable seccomp to safely compute untrusted bytecode"
1529 This kernel feature is useful for number crunching applications
1530 that may need to compute untrusted bytecode during their
1531 execution. By using pipes or other transports made available to
1532 the process as file descriptors supporting the read/write
1533 syscalls, it's possible to isolate those applications in
1534 their own address space using seccomp. Once seccomp is
1535 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1536 and the task is only allowed to execute a few safe syscalls
1537 defined by each seccomp mode.
1539 If unsure, say Y. Only embedded should say N here.
1541 config CC_STACKPROTECTOR
1542 bool "Enable -fstack-protector buffer overflow detection"
1544 This option turns on the -fstack-protector GCC feature. This
1545 feature puts, at the beginning of functions, a canary value on
1546 the stack just before the return address, and validates
1547 the value just before actually returning. Stack based buffer
1548 overflows (that need to overwrite this return address) now also
1549 overwrite the canary, which gets detected and the attack is then
1550 neutralized via a kernel panic.
1552 This feature requires gcc version 4.2 or above, or a distribution
1553 gcc with the feature backported. Older versions are automatically
1554 detected and for those versions, this configuration option is
1555 ignored. (and a warning is printed during bootup)
1557 source kernel/Kconfig.hz
1560 bool "kexec system call"
1562 kexec is a system call that implements the ability to shutdown your
1563 current kernel, and to start another kernel. It is like a reboot
1564 but it is independent of the system firmware. And like a reboot
1565 you can start any kernel with it, not just Linux.
1567 The name comes from the similarity to the exec system call.
1569 It is an ongoing process to be certain the hardware in a machine
1570 is properly shutdown, so do not be surprised if this code does not
1571 initially work for you. It may help to enable device hotplugging
1572 support. As of this writing the exact hardware interface is
1573 strongly in flux, so no good recommendation can be made.
1576 bool "kernel crash dumps"
1577 depends on X86_64 || (X86_32 && HIGHMEM)
1579 Generate crash dump after being started by kexec.
1580 This should be normally only set in special crash dump kernels
1581 which are loaded in the main kernel with kexec-tools into
1582 a specially reserved region and then later executed after
1583 a crash by kdump/kexec. The crash dump kernel must be compiled
1584 to a memory address not used by the main kernel or BIOS using
1585 PHYSICAL_START, or it must be built as a relocatable image
1586 (CONFIG_RELOCATABLE=y).
1587 For more details see Documentation/kdump/kdump.txt
1590 bool "kexec jump (EXPERIMENTAL)"
1591 depends on EXPERIMENTAL
1592 depends on KEXEC && HIBERNATION
1594 Jump between original kernel and kexeced kernel and invoke
1595 code in physical address mode via KEXEC
1597 config PHYSICAL_START
1598 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1601 This gives the physical address where the kernel is loaded.
1603 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1604 bzImage will decompress itself to above physical address and
1605 run from there. Otherwise, bzImage will run from the address where
1606 it has been loaded by the boot loader and will ignore above physical
1609 In normal kdump cases one does not have to set/change this option
1610 as now bzImage can be compiled as a completely relocatable image
1611 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1612 address. This option is mainly useful for the folks who don't want
1613 to use a bzImage for capturing the crash dump and want to use a
1614 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1615 to be specifically compiled to run from a specific memory area
1616 (normally a reserved region) and this option comes handy.
1618 So if you are using bzImage for capturing the crash dump,
1619 leave the value here unchanged to 0x1000000 and set
1620 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1621 for capturing the crash dump change this value to start of
1622 the reserved region. In other words, it can be set based on
1623 the "X" value as specified in the "crashkernel=YM@XM"
1624 command line boot parameter passed to the panic-ed
1625 kernel. Please take a look at Documentation/kdump/kdump.txt
1626 for more details about crash dumps.
1628 Usage of bzImage for capturing the crash dump is recommended as
1629 one does not have to build two kernels. Same kernel can be used
1630 as production kernel and capture kernel. Above option should have
1631 gone away after relocatable bzImage support is introduced. But it
1632 is present because there are users out there who continue to use
1633 vmlinux for dump capture. This option should go away down the
1636 Don't change this unless you know what you are doing.
1639 bool "Build a relocatable kernel"
1642 This builds a kernel image that retains relocation information
1643 so it can be loaded someplace besides the default 1MB.
1644 The relocations tend to make the kernel binary about 10% larger,
1645 but are discarded at runtime.
1647 One use is for the kexec on panic case where the recovery kernel
1648 must live at a different physical address than the primary
1651 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1652 it has been loaded at and the compile time physical address
1653 (CONFIG_PHYSICAL_START) is ignored.
1655 # Relocation on x86-32 needs some additional build support
1656 config X86_NEED_RELOCS
1658 depends on X86_32 && RELOCATABLE
1660 config PHYSICAL_ALIGN
1661 hex "Alignment value to which kernel should be aligned" if X86_32
1663 range 0x2000 0x1000000
1665 This value puts the alignment restrictions on physical address
1666 where kernel is loaded and run from. Kernel is compiled for an
1667 address which meets above alignment restriction.
1669 If bootloader loads the kernel at a non-aligned address and
1670 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1671 address aligned to above value and run from there.
1673 If bootloader loads the kernel at a non-aligned address and
1674 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1675 load address and decompress itself to the address it has been
1676 compiled for and run from there. The address for which kernel is
1677 compiled already meets above alignment restrictions. Hence the
1678 end result is that kernel runs from a physical address meeting
1679 above alignment restrictions.
1681 Don't change this unless you know what you are doing.
1684 bool "Support for hot-pluggable CPUs"
1685 depends on SMP && HOTPLUG
1687 Say Y here to allow turning CPUs off and on. CPUs can be
1688 controlled through /sys/devices/system/cpu.
1689 ( Note: power management support will enable this option
1690 automatically on SMP systems. )
1691 Say N if you want to disable CPU hotplug.
1695 prompt "Compat VDSO support"
1696 depends on X86_32 || IA32_EMULATION
1698 Map the 32-bit VDSO to the predictable old-style address too.
1700 Say N here if you are running a sufficiently recent glibc
1701 version (2.3.3 or later), to remove the high-mapped
1702 VDSO mapping and to exclusively use the randomized VDSO.
1707 bool "Built-in kernel command line"
1709 Allow for specifying boot arguments to the kernel at
1710 build time. On some systems (e.g. embedded ones), it is
1711 necessary or convenient to provide some or all of the
1712 kernel boot arguments with the kernel itself (that is,
1713 to not rely on the boot loader to provide them.)
1715 To compile command line arguments into the kernel,
1716 set this option to 'Y', then fill in the
1717 the boot arguments in CONFIG_CMDLINE.
1719 Systems with fully functional boot loaders (i.e. non-embedded)
1720 should leave this option set to 'N'.
1723 string "Built-in kernel command string"
1724 depends on CMDLINE_BOOL
1727 Enter arguments here that should be compiled into the kernel
1728 image and used at boot time. If the boot loader provides a
1729 command line at boot time, it is appended to this string to
1730 form the full kernel command line, when the system boots.
1732 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1733 change this behavior.
1735 In most cases, the command line (whether built-in or provided
1736 by the boot loader) should specify the device for the root
1739 config CMDLINE_OVERRIDE
1740 bool "Built-in command line overrides boot loader arguments"
1741 depends on CMDLINE_BOOL
1743 Set this option to 'Y' to have the kernel ignore the boot loader
1744 command line, and use ONLY the built-in command line.
1746 This is used to work around broken boot loaders. This should
1747 be set to 'N' under normal conditions.
1751 config ARCH_ENABLE_MEMORY_HOTPLUG
1753 depends on X86_64 || (X86_32 && HIGHMEM)
1755 config ARCH_ENABLE_MEMORY_HOTREMOVE
1757 depends on MEMORY_HOTPLUG
1759 config USE_PERCPU_NUMA_NODE_ID
1763 menu "Power management and ACPI options"
1765 config ARCH_HIBERNATION_HEADER
1767 depends on X86_64 && HIBERNATION
1769 source "kernel/power/Kconfig"
1771 source "drivers/acpi/Kconfig"
1773 source "drivers/sfi/Kconfig"
1780 tristate "APM (Advanced Power Management) BIOS support"
1781 depends on X86_32 && PM_SLEEP
1783 APM is a BIOS specification for saving power using several different
1784 techniques. This is mostly useful for battery powered laptops with
1785 APM compliant BIOSes. If you say Y here, the system time will be
1786 reset after a RESUME operation, the /proc/apm device will provide
1787 battery status information, and user-space programs will receive
1788 notification of APM "events" (e.g. battery status change).
1790 If you select "Y" here, you can disable actual use of the APM
1791 BIOS by passing the "apm=off" option to the kernel at boot time.
1793 Note that the APM support is almost completely disabled for
1794 machines with more than one CPU.
1796 In order to use APM, you will need supporting software. For location
1797 and more information, read <file:Documentation/power/apm-acpi.txt>
1798 and the Battery Powered Linux mini-HOWTO, available from
1799 <http://www.tldp.org/docs.html#howto>.
1801 This driver does not spin down disk drives (see the hdparm(8)
1802 manpage ("man 8 hdparm") for that), and it doesn't turn off
1803 VESA-compliant "green" monitors.
1805 This driver does not support the TI 4000M TravelMate and the ACER
1806 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1807 desktop machines also don't have compliant BIOSes, and this driver
1808 may cause those machines to panic during the boot phase.
1810 Generally, if you don't have a battery in your machine, there isn't
1811 much point in using this driver and you should say N. If you get
1812 random kernel OOPSes or reboots that don't seem to be related to
1813 anything, try disabling/enabling this option (or disabling/enabling
1816 Some other things you should try when experiencing seemingly random,
1819 1) make sure that you have enough swap space and that it is
1821 2) pass the "no-hlt" option to the kernel
1822 3) switch on floating point emulation in the kernel and pass
1823 the "no387" option to the kernel
1824 4) pass the "floppy=nodma" option to the kernel
1825 5) pass the "mem=4M" option to the kernel (thereby disabling
1826 all but the first 4 MB of RAM)
1827 6) make sure that the CPU is not over clocked.
1828 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1829 8) disable the cache from your BIOS settings
1830 9) install a fan for the video card or exchange video RAM
1831 10) install a better fan for the CPU
1832 11) exchange RAM chips
1833 12) exchange the motherboard.
1835 To compile this driver as a module, choose M here: the
1836 module will be called apm.
1840 config APM_IGNORE_USER_SUSPEND
1841 bool "Ignore USER SUSPEND"
1843 This option will ignore USER SUSPEND requests. On machines with a
1844 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1845 series notebooks, it is necessary to say Y because of a BIOS bug.
1847 config APM_DO_ENABLE
1848 bool "Enable PM at boot time"
1850 Enable APM features at boot time. From page 36 of the APM BIOS
1851 specification: "When disabled, the APM BIOS does not automatically
1852 power manage devices, enter the Standby State, enter the Suspend
1853 State, or take power saving steps in response to CPU Idle calls."
1854 This driver will make CPU Idle calls when Linux is idle (unless this
1855 feature is turned off -- see "Do CPU IDLE calls", below). This
1856 should always save battery power, but more complicated APM features
1857 will be dependent on your BIOS implementation. You may need to turn
1858 this option off if your computer hangs at boot time when using APM
1859 support, or if it beeps continuously instead of suspending. Turn
1860 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1861 T400CDT. This is off by default since most machines do fine without
1865 bool "Make CPU Idle calls when idle"
1867 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1868 On some machines, this can activate improved power savings, such as
1869 a slowed CPU clock rate, when the machine is idle. These idle calls
1870 are made after the idle loop has run for some length of time (e.g.,
1871 333 mS). On some machines, this will cause a hang at boot time or
1872 whenever the CPU becomes idle. (On machines with more than one CPU,
1873 this option does nothing.)
1875 config APM_DISPLAY_BLANK
1876 bool "Enable console blanking using APM"
1878 Enable console blanking using the APM. Some laptops can use this to
1879 turn off the LCD backlight when the screen blanker of the Linux
1880 virtual console blanks the screen. Note that this is only used by
1881 the virtual console screen blanker, and won't turn off the backlight
1882 when using the X Window system. This also doesn't have anything to
1883 do with your VESA-compliant power-saving monitor. Further, this
1884 option doesn't work for all laptops -- it might not turn off your
1885 backlight at all, or it might print a lot of errors to the console,
1886 especially if you are using gpm.
1888 config APM_ALLOW_INTS
1889 bool "Allow interrupts during APM BIOS calls"
1891 Normally we disable external interrupts while we are making calls to
1892 the APM BIOS as a measure to lessen the effects of a badly behaving
1893 BIOS implementation. The BIOS should reenable interrupts if it
1894 needs to. Unfortunately, some BIOSes do not -- especially those in
1895 many of the newer IBM Thinkpads. If you experience hangs when you
1896 suspend, try setting this to Y. Otherwise, say N.
1900 source "drivers/cpufreq/Kconfig"
1902 source "drivers/cpuidle/Kconfig"
1904 source "drivers/idle/Kconfig"
1909 menu "Bus options (PCI etc.)"
1914 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1916 Find out whether you have a PCI motherboard. PCI is the name of a
1917 bus system, i.e. the way the CPU talks to the other stuff inside
1918 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1919 VESA. If you have PCI, say Y, otherwise N.
1922 prompt "PCI access mode"
1923 depends on X86_32 && PCI
1926 On PCI systems, the BIOS can be used to detect the PCI devices and
1927 determine their configuration. However, some old PCI motherboards
1928 have BIOS bugs and may crash if this is done. Also, some embedded
1929 PCI-based systems don't have any BIOS at all. Linux can also try to
1930 detect the PCI hardware directly without using the BIOS.
1932 With this option, you can specify how Linux should detect the
1933 PCI devices. If you choose "BIOS", the BIOS will be used,
1934 if you choose "Direct", the BIOS won't be used, and if you
1935 choose "MMConfig", then PCI Express MMCONFIG will be used.
1936 If you choose "Any", the kernel will try MMCONFIG, then the
1937 direct access method and falls back to the BIOS if that doesn't
1938 work. If unsure, go with the default, which is "Any".
1943 config PCI_GOMMCONFIG
1960 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1962 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1965 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1969 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1973 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1977 depends on PCI && XEN
1985 bool "Support mmconfig PCI config space access"
1986 depends on X86_64 && PCI && ACPI
1988 config PCI_CNB20LE_QUIRK
1989 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1990 depends on PCI && EXPERIMENTAL
1992 Read the PCI windows out of the CNB20LE host bridge. This allows
1993 PCI hotplug to work on systems with the CNB20LE chipset which do
1996 There's no public spec for this chipset, and this functionality
1997 is known to be incomplete.
1999 You should say N unless you know you need this.
2001 source "drivers/pci/pcie/Kconfig"
2003 source "drivers/pci/Kconfig"
2005 # x86_64 have no ISA slots, but can have ISA-style DMA.
2007 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2010 Enables ISA-style DMA support for devices requiring such controllers.
2018 Find out whether you have ISA slots on your motherboard. ISA is the
2019 name of a bus system, i.e. the way the CPU talks to the other stuff
2020 inside your box. Other bus systems are PCI, EISA, MicroChannel
2021 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2022 newer boards don't support it. If you have ISA, say Y, otherwise N.
2028 The Extended Industry Standard Architecture (EISA) bus was
2029 developed as an open alternative to the IBM MicroChannel bus.
2031 The EISA bus provided some of the features of the IBM MicroChannel
2032 bus while maintaining backward compatibility with cards made for
2033 the older ISA bus. The EISA bus saw limited use between 1988 and
2034 1995 when it was made obsolete by the PCI bus.
2036 Say Y here if you are building a kernel for an EISA-based machine.
2040 source "drivers/eisa/Kconfig"
2043 tristate "NatSemi SCx200 support"
2045 This provides basic support for National Semiconductor's
2046 (now AMD's) Geode processors. The driver probes for the
2047 PCI-IDs of several on-chip devices, so its a good dependency
2048 for other scx200_* drivers.
2050 If compiled as a module, the driver is named scx200.
2052 config SCx200HR_TIMER
2053 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2057 This driver provides a clocksource built upon the on-chip
2058 27MHz high-resolution timer. Its also a workaround for
2059 NSC Geode SC-1100's buggy TSC, which loses time when the
2060 processor goes idle (as is done by the scheduler). The
2061 other workaround is idle=poll boot option.
2064 bool "One Laptop Per Child support"
2071 Add support for detecting the unique features of the OLPC
2075 bool "OLPC XO-1 Power Management"
2076 depends on OLPC && MFD_CS5535 && PM_SLEEP
2079 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2082 bool "OLPC XO-1 Real Time Clock"
2083 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2085 Add support for the XO-1 real time clock, which can be used as a
2086 programmable wakeup source.
2089 bool "OLPC XO-1 SCI extras"
2090 depends on OLPC && OLPC_XO1_PM
2095 Add support for SCI-based features of the OLPC XO-1 laptop:
2096 - EC-driven system wakeups
2100 - AC adapter status updates
2101 - Battery status updates
2103 config OLPC_XO15_SCI
2104 bool "OLPC XO-1.5 SCI extras"
2105 depends on OLPC && ACPI
2108 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2109 - EC-driven system wakeups
2110 - AC adapter status updates
2111 - Battery status updates
2114 bool "PCEngines ALIX System Support (LED setup)"
2117 This option enables system support for the PCEngines ALIX.
2118 At present this just sets up LEDs for GPIO control on
2119 ALIX2/3/6 boards. However, other system specific setup should
2122 Note: You must still enable the drivers for GPIO and LED support
2123 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2125 Note: You have to set alix.force=1 for boards with Award BIOS.
2128 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2131 This option enables system support for the Soekris Engineering net5501.
2134 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2138 This option enables system support for the Traverse Technologies GEOS.
2144 depends on CPU_SUP_AMD && PCI
2146 source "drivers/pcmcia/Kconfig"
2148 source "drivers/pci/hotplug/Kconfig"
2151 bool "RapidIO support"
2155 If you say Y here, the kernel will include drivers and
2156 infrastructure code to support RapidIO interconnect devices.
2158 source "drivers/rapidio/Kconfig"
2163 menu "Executable file formats / Emulations"
2165 source "fs/Kconfig.binfmt"
2167 config IA32_EMULATION
2168 bool "IA32 Emulation"
2170 select COMPAT_BINFMT_ELF
2172 Include code to run legacy 32-bit programs under a
2173 64-bit kernel. You should likely turn this on, unless you're
2174 100% sure that you don't have any 32-bit programs left.
2177 tristate "IA32 a.out support"
2178 depends on IA32_EMULATION
2180 Support old a.out binaries in the 32bit emulation.
2183 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2184 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2186 Include code to run binaries for the x32 native 32-bit ABI
2187 for 64-bit processors. An x32 process gets access to the
2188 full 64-bit register file and wide data path while leaving
2189 pointers at 32 bits for smaller memory footprint.
2191 You will need a recent binutils (2.22 or later) with
2192 elf32_x86_64 support enabled to compile a kernel with this
2197 depends on IA32_EMULATION || X86_X32
2198 select ARCH_WANT_OLD_COMPAT_IPC
2201 config COMPAT_FOR_U64_ALIGNMENT
2204 config SYSVIPC_COMPAT
2216 config HAVE_ATOMIC_IOMAP
2220 config HAVE_TEXT_POKE_SMP
2222 select STOP_MACHINE if SMP
2224 config X86_DEV_DMA_OPS
2226 depends on X86_64 || STA2X11
2228 config X86_DMA_REMAP
2232 source "net/Kconfig"
2234 source "drivers/Kconfig"
2236 source "drivers/firmware/Kconfig"
2240 source "arch/x86/Kconfig.debug"
2242 source "security/Kconfig"
2244 source "crypto/Kconfig"
2246 source "arch/x86/kvm/Kconfig"
2248 source "lib/Kconfig"