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 HAVE_AOUT if X86_32
21 select HAVE_UNSTABLE_SCHED_CLOCK
24 select HAVE_PERF_EVENTS
26 select HAVE_IOREMAP_PROT
29 select ARCH_WANT_OPTIONAL_GPIOLIB
30 select ARCH_WANT_FRAME_POINTERS
32 select HAVE_KRETPROBES
34 select HAVE_FTRACE_MCOUNT_RECORD
35 select HAVE_C_RECORDMCOUNT
36 select HAVE_DYNAMIC_FTRACE
37 select HAVE_FUNCTION_TRACER
38 select HAVE_FUNCTION_GRAPH_TRACER
39 select HAVE_FUNCTION_GRAPH_FP_TEST
40 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
41 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
42 select HAVE_SYSCALL_TRACEPOINTS
45 select HAVE_ARCH_TRACEHOOK
46 select HAVE_GENERIC_DMA_COHERENT if X86_32
47 select HAVE_EFFICIENT_UNALIGNED_ACCESS
48 select USER_STACKTRACE_SUPPORT
49 select HAVE_REGS_AND_STACK_ACCESS_API
50 select HAVE_DMA_API_DEBUG
51 select HAVE_KERNEL_GZIP
52 select HAVE_KERNEL_BZIP2
53 select HAVE_KERNEL_LZMA
55 select HAVE_KERNEL_LZO
56 select HAVE_HW_BREAKPOINT
57 select HAVE_MIXED_BREAKPOINTS_REGS
59 select HAVE_PERF_EVENTS_NMI
61 select HAVE_ARCH_KMEMCHECK
62 select HAVE_USER_RETURN_NOTIFIER
63 select HAVE_ARCH_JUMP_LABEL
64 select HAVE_TEXT_POKE_SMP
65 select HAVE_GENERIC_HARDIRQS
66 select HAVE_SPARSE_IRQ
67 select GENERIC_FIND_FIRST_BIT
68 select GENERIC_FIND_NEXT_BIT
69 select GENERIC_IRQ_PROBE
70 select GENERIC_PENDING_IRQ if SMP
71 select GENERIC_IRQ_SHOW
72 select IRQ_FORCED_THREADING
73 select USE_GENERIC_SMP_HELPERS if SMP
75 config INSTRUCTION_DECODER
76 def_bool (KPROBES || PERF_EVENTS)
80 default "elf32-i386" if X86_32
81 default "elf64-x86-64" if X86_64
85 default "arch/x86/configs/i386_defconfig" if X86_32
86 default "arch/x86/configs/x86_64_defconfig" if X86_64
88 config GENERIC_CMOS_UPDATE
91 config CLOCKSOURCE_WATCHDOG
94 config GENERIC_CLOCKEVENTS
97 config GENERIC_CLOCKEVENTS_BROADCAST
99 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
101 config LOCKDEP_SUPPORT
104 config STACKTRACE_SUPPORT
107 config HAVE_LATENCYTOP_SUPPORT
119 config NEED_DMA_MAP_STATE
120 def_bool (X86_64 || DMAR || DMA_API_DEBUG)
122 config NEED_SG_DMA_LENGTH
125 config GENERIC_ISA_DMA
134 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
136 config GENERIC_BUG_RELATIVE_POINTERS
139 config GENERIC_HWEIGHT
145 config ARCH_MAY_HAVE_PC_FDC
148 config RWSEM_GENERIC_SPINLOCK
151 config RWSEM_XCHGADD_ALGORITHM
154 config ARCH_HAS_CPU_IDLE_WAIT
157 config GENERIC_CALIBRATE_DELAY
160 config GENERIC_TIME_VSYSCALL
164 config ARCH_HAS_CPU_RELAX
167 config ARCH_HAS_DEFAULT_IDLE
170 config ARCH_HAS_CACHE_LINE_SIZE
173 config HAVE_SETUP_PER_CPU_AREA
176 config NEED_PER_CPU_EMBED_FIRST_CHUNK
179 config NEED_PER_CPU_PAGE_FIRST_CHUNK
182 config HAVE_CPUMASK_OF_CPU_MAP
185 config ARCH_HIBERNATION_POSSIBLE
188 config ARCH_SUSPEND_POSSIBLE
195 config ARCH_POPULATES_NODE_MAP
202 config ARCH_SUPPORTS_OPTIMIZED_INLINING
205 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
208 config HAVE_INTEL_TXT
210 depends on EXPERIMENTAL && DMAR && ACPI
214 depends on X86_32 && SMP
218 depends on X86_64 && SMP
224 config X86_TRAMPOLINE
226 depends on SMP || (64BIT && ACPI_SLEEP)
228 config X86_32_LAZY_GS
230 depends on X86_32 && !CC_STACKPROTECTOR
232 config ARCH_HWEIGHT_CFLAGS
234 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
235 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
240 config ARCH_CPU_PROBE_RELEASE
242 depends on HOTPLUG_CPU
244 source "init/Kconfig"
245 source "kernel/Kconfig.freezer"
247 menu "Processor type and features"
249 source "kernel/time/Kconfig"
252 bool "Symmetric multi-processing support"
254 This enables support for systems with more than one CPU. If you have
255 a system with only one CPU, like most personal computers, say N. If
256 you have a system with more than one CPU, say Y.
258 If you say N here, the kernel will run on single and multiprocessor
259 machines, but will use only one CPU of a multiprocessor machine. If
260 you say Y here, the kernel will run on many, but not all,
261 singleprocessor machines. On a singleprocessor machine, the kernel
262 will run faster if you say N here.
264 Note that if you say Y here and choose architecture "586" or
265 "Pentium" under "Processor family", the kernel will not work on 486
266 architectures. Similarly, multiprocessor kernels for the "PPro"
267 architecture may not work on all Pentium based boards.
269 People using multiprocessor machines who say Y here should also say
270 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
271 Management" code will be disabled if you say Y here.
273 See also <file:Documentation/i386/IO-APIC.txt>,
274 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
275 <http://www.tldp.org/docs.html#howto>.
277 If you don't know what to do here, say N.
280 bool "Support x2apic"
281 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
283 This enables x2apic support on CPUs that have this feature.
285 This allows 32-bit apic IDs (so it can support very large systems),
286 and accesses the local apic via MSRs not via mmio.
288 If you don't know what to do here, say N.
291 bool "Enable MPS table" if ACPI
293 depends on X86_LOCAL_APIC
295 For old smp systems that do not have proper acpi support. Newer systems
296 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
299 bool "Support for big SMP systems with more than 8 CPUs"
300 depends on X86_32 && SMP
302 This option is needed for the systems that have more than 8 CPUs
305 config X86_EXTENDED_PLATFORM
306 bool "Support for extended (non-PC) x86 platforms"
309 If you disable this option then the kernel will only support
310 standard PC platforms. (which covers the vast majority of
313 If you enable this option then you'll be able to select support
314 for the following (non-PC) 32 bit x86 platforms:
318 SGI 320/540 (Visual Workstation)
319 Summit/EXA (IBM x440)
320 Unisys ES7000 IA32 series
321 Moorestown MID devices
323 If you have one of these systems, or if you want to build a
324 generic distribution kernel, say Y here - otherwise say N.
328 config X86_EXTENDED_PLATFORM
329 bool "Support for extended (non-PC) x86 platforms"
332 If you disable this option then the kernel will only support
333 standard PC platforms. (which covers the vast majority of
336 If you enable this option then you'll be able to select support
337 for the following (non-PC) 64 bit x86 platforms:
341 If you have one of these systems, or if you want to build a
342 generic distribution kernel, say Y here - otherwise say N.
344 # This is an alphabetically sorted list of 64 bit extended platforms
345 # Please maintain the alphabetic order if and when there are additions
349 select PARAVIRT_GUEST
351 depends on X86_64 && PCI
352 depends on X86_EXTENDED_PLATFORM
354 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
355 supposed to run on these EM64T-based machines. Only choose this option
356 if you have one of these machines.
359 bool "SGI Ultraviolet"
361 depends on X86_EXTENDED_PLATFORM
363 depends on X86_X2APIC
365 This option is needed in order to support SGI Ultraviolet systems.
366 If you don't have one of these, you should say N here.
368 # Following is an alphabetically sorted list of 32 bit extended platforms
369 # Please maintain the alphabetic order if and when there are additions
374 depends on X86_EXTENDED_PLATFORM
376 Select this for an AMD Elan processor.
378 Do not use this option for K6/Athlon/Opteron processors!
380 If unsure, choose "PC-compatible" instead.
383 bool "CE4100 TV platform"
385 depends on PCI_GODIRECT
387 depends on X86_EXTENDED_PLATFORM
388 select X86_REBOOTFIXUPS
390 Select for the Intel CE media processor (CE4100) SOC.
391 This option compiles in support for the CE4100 SOC for settop
392 boxes and media devices.
395 bool "Moorestown MID platform"
399 depends on X86_EXTENDED_PLATFORM
400 depends on X86_IO_APIC
405 select X86_PLATFORM_DEVICES
407 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
408 Internet Device(MID) platform. Moorestown consists of two chips:
409 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
410 Unlike standard x86 PCs, Moorestown does not have many legacy devices
411 nor standard legacy replacement devices/features. e.g. Moorestown does
412 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
415 bool "RDC R-321x SoC"
417 depends on X86_EXTENDED_PLATFORM
419 select X86_REBOOTFIXUPS
421 This option is needed for RDC R-321x system-on-chip, also known
423 If you don't have one of these chips, you should say N here.
425 config X86_32_NON_STANDARD
426 bool "Support non-standard 32-bit SMP architectures"
427 depends on X86_32 && SMP
428 depends on X86_EXTENDED_PLATFORM
430 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
431 subarchitectures. It is intended for a generic binary kernel.
432 if you select them all, kernel will probe it one by one. and will
435 # Alphabetically sorted list of Non standard 32 bit platforms
438 bool "NUMAQ (IBM/Sequent)"
439 depends on X86_32_NON_STANDARD
444 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
445 NUMA multiquad box. This changes the way that processors are
446 bootstrapped, and uses Clustered Logical APIC addressing mode instead
447 of Flat Logical. You will need a new lynxer.elf file to flash your
448 firmware with - send email to <Martin.Bligh@us.ibm.com>.
450 config X86_SUPPORTS_MEMORY_FAILURE
452 # MCE code calls memory_failure():
454 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
455 depends on !X86_NUMAQ
456 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
457 depends on X86_64 || !SPARSEMEM
458 select ARCH_SUPPORTS_MEMORY_FAILURE
461 bool "SGI 320/540 (Visual Workstation)"
462 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
463 depends on X86_32_NON_STANDARD
465 The SGI Visual Workstation series is an IA32-based workstation
466 based on SGI systems chips with some legacy PC hardware attached.
468 Say Y here to create a kernel to run on the SGI 320 or 540.
470 A kernel compiled for the Visual Workstation will run on general
471 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
474 bool "Summit/EXA (IBM x440)"
475 depends on X86_32_NON_STANDARD
477 This option is needed for IBM systems that use the Summit/EXA chipset.
478 In particular, it is needed for the x440.
481 bool "Unisys ES7000 IA32 series"
482 depends on X86_32_NON_STANDARD && X86_BIGSMP
484 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
485 supposed to run on an IA32-based Unisys ES7000 system.
488 tristate "Eurobraille/Iris poweroff module"
491 The Iris machines from EuroBraille do not have APM or ACPI support
492 to shut themselves down properly. A special I/O sequence is
493 needed to do so, which is what this module does at
496 This is only for Iris machines from EuroBraille.
500 config SCHED_OMIT_FRAME_POINTER
502 prompt "Single-depth WCHAN output"
505 Calculate simpler /proc/<PID>/wchan values. If this option
506 is disabled then wchan values will recurse back to the
507 caller function. This provides more accurate wchan values,
508 at the expense of slightly more scheduling overhead.
510 If in doubt, say "Y".
512 menuconfig PARAVIRT_GUEST
513 bool "Paravirtualized guest support"
515 Say Y here to get to see options related to running Linux under
516 various hypervisors. This option alone does not add any kernel code.
518 If you say N, all options in this submenu will be skipped and disabled.
522 source "arch/x86/xen/Kconfig"
525 bool "KVM paravirtualized clock"
527 select PARAVIRT_CLOCK
529 Turning on this option will allow you to run a paravirtualized clock
530 when running over the KVM hypervisor. Instead of relying on a PIT
531 (or probably other) emulation by the underlying device model, the host
532 provides the guest with timing infrastructure such as time of day, and
536 bool "KVM Guest support"
539 This option enables various optimizations for running under the KVM
542 source "arch/x86/lguest/Kconfig"
545 bool "Enable paravirtualization code"
547 This changes the kernel so it can modify itself when it is run
548 under a hypervisor, potentially improving performance significantly
549 over full virtualization. However, when run without a hypervisor
550 the kernel is theoretically slower and slightly larger.
552 config PARAVIRT_SPINLOCKS
553 bool "Paravirtualization layer for spinlocks"
554 depends on PARAVIRT && SMP && EXPERIMENTAL
556 Paravirtualized spinlocks allow a pvops backend to replace the
557 spinlock implementation with something virtualization-friendly
558 (for example, block the virtual CPU rather than spinning).
560 Unfortunately the downside is an up to 5% performance hit on
561 native kernels, with various workloads.
563 If you are unsure how to answer this question, answer N.
565 config PARAVIRT_CLOCK
570 config PARAVIRT_DEBUG
571 bool "paravirt-ops debugging"
572 depends on PARAVIRT && DEBUG_KERNEL
574 Enable to debug paravirt_ops internals. Specifically, BUG if
575 a paravirt_op is missing when it is called.
583 This option adds a kernel parameter 'memtest', which allows memtest
585 memtest=0, mean disabled; -- default
586 memtest=1, mean do 1 test pattern;
588 memtest=4, mean do 4 test patterns.
589 If you are unsure how to answer this question, answer N.
591 config X86_SUMMIT_NUMA
593 depends on X86_32 && NUMA && X86_32_NON_STANDARD
595 config X86_CYCLONE_TIMER
597 depends on X86_32_NON_STANDARD
599 source "arch/x86/Kconfig.cpu"
603 prompt "HPET Timer Support" if X86_32
605 Use the IA-PC HPET (High Precision Event Timer) to manage
606 time in preference to the PIT and RTC, if a HPET is
608 HPET is the next generation timer replacing legacy 8254s.
609 The HPET provides a stable time base on SMP
610 systems, unlike the TSC, but it is more expensive to access,
611 as it is off-chip. You can find the HPET spec at
612 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
614 You can safely choose Y here. However, HPET will only be
615 activated if the platform and the BIOS support this feature.
616 Otherwise the 8254 will be used for timing services.
618 Choose N to continue using the legacy 8254 timer.
620 config HPET_EMULATE_RTC
622 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
626 prompt "Langwell APB Timer Support" if X86_MRST
628 APB timer is the replacement for 8254, HPET on X86 MID platforms.
629 The APBT provides a stable time base on SMP
630 systems, unlike the TSC, but it is more expensive to access,
631 as it is off-chip. APB timers are always running regardless of CPU
632 C states, they are used as per CPU clockevent device when possible.
634 # Mark as expert because too many people got it wrong.
635 # The code disables itself when not needed.
638 bool "Enable DMI scanning" if EXPERT
640 Enabled scanning of DMI to identify machine quirks. Say Y
641 here unless you have verified that your setup is not
642 affected by entries in the DMI blacklist. Required by PNP
646 bool "GART IOMMU support" if EXPERT
649 depends on X86_64 && PCI && AMD_NB
651 Support for full DMA access of devices with 32bit memory access only
652 on systems with more than 3GB. This is usually needed for USB,
653 sound, many IDE/SATA chipsets and some other devices.
654 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
655 based hardware IOMMU and a software bounce buffer based IOMMU used
656 on Intel systems and as fallback.
657 The code is only active when needed (enough memory and limited
658 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
662 bool "IBM Calgary IOMMU support"
664 depends on X86_64 && PCI && EXPERIMENTAL
666 Support for hardware IOMMUs in IBM's xSeries x366 and x460
667 systems. Needed to run systems with more than 3GB of memory
668 properly with 32-bit PCI devices that do not support DAC
669 (Double Address Cycle). Calgary also supports bus level
670 isolation, where all DMAs pass through the IOMMU. This
671 prevents them from going anywhere except their intended
672 destination. This catches hard-to-find kernel bugs and
673 mis-behaving drivers and devices that do not use the DMA-API
674 properly to set up their DMA buffers. The IOMMU can be
675 turned off at boot time with the iommu=off parameter.
676 Normally the kernel will make the right choice by itself.
679 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
681 prompt "Should Calgary be enabled by default?"
682 depends on CALGARY_IOMMU
684 Should Calgary be enabled by default? if you choose 'y', Calgary
685 will be used (if it exists). If you choose 'n', Calgary will not be
686 used even if it exists. If you choose 'n' and would like to use
687 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
691 bool "AMD IOMMU support"
694 depends on X86_64 && PCI && ACPI
696 With this option you can enable support for AMD IOMMU hardware in
697 your system. An IOMMU is a hardware component which provides
698 remapping of DMA memory accesses from devices. With an AMD IOMMU you
699 can isolate the the DMA memory of different devices and protect the
700 system from misbehaving device drivers or hardware.
702 You can find out if your system has an AMD IOMMU if you look into
703 your BIOS for an option to enable it or if you have an IVRS ACPI
706 config AMD_IOMMU_STATS
707 bool "Export AMD IOMMU statistics to debugfs"
711 This option enables code in the AMD IOMMU driver to collect various
712 statistics about whats happening in the driver and exports that
713 information to userspace via debugfs.
716 # need this always selected by IOMMU for the VIA workaround
720 Support for software bounce buffers used on x86-64 systems
721 which don't have a hardware IOMMU (e.g. the current generation
722 of Intel's x86-64 CPUs). Using this PCI devices which can only
723 access 32-bits of memory can be used on systems with more than
724 3 GB of memory. If unsure, say Y.
727 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
730 def_bool (AMD_IOMMU || DMAR)
733 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
734 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
735 select CPUMASK_OFFSTACK
737 Enable maximum number of CPUS and NUMA Nodes for this architecture.
741 int "Maximum number of CPUs" if SMP && !MAXSMP
742 range 2 8 if SMP && X86_32 && !X86_BIGSMP
743 range 2 512 if SMP && !MAXSMP
745 default "4096" if MAXSMP
746 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
749 This allows you to specify the maximum number of CPUs which this
750 kernel will support. The maximum supported value is 512 and the
751 minimum value which makes sense is 2.
753 This is purely to save memory - each supported CPU adds
754 approximately eight kilobytes to the kernel image.
757 bool "SMT (Hyperthreading) scheduler support"
760 SMT scheduler support improves the CPU scheduler's decision making
761 when dealing with Intel Pentium 4 chips with HyperThreading at a
762 cost of slightly increased overhead in some places. If unsure say
767 prompt "Multi-core scheduler support"
770 Multi-core scheduler support improves the CPU scheduler's decision
771 making when dealing with multi-core CPU chips at a cost of slightly
772 increased overhead in some places. If unsure say N here.
774 config IRQ_TIME_ACCOUNTING
775 bool "Fine granularity task level IRQ time accounting"
778 Select this option to enable fine granularity task irq time
779 accounting. This is done by reading a timestamp on each
780 transitions between softirq and hardirq state, so there can be a
781 small performance impact.
783 If in doubt, say N here.
785 source "kernel/Kconfig.preempt"
788 bool "Local APIC support on uniprocessors"
789 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
791 A local APIC (Advanced Programmable Interrupt Controller) is an
792 integrated interrupt controller in the CPU. If you have a single-CPU
793 system which has a processor with a local APIC, you can say Y here to
794 enable and use it. If you say Y here even though your machine doesn't
795 have a local APIC, then the kernel will still run with no slowdown at
796 all. The local APIC supports CPU-generated self-interrupts (timer,
797 performance counters), and the NMI watchdog which detects hard
801 bool "IO-APIC support on uniprocessors"
802 depends on X86_UP_APIC
804 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
805 SMP-capable replacement for PC-style interrupt controllers. Most
806 SMP systems and many recent uniprocessor systems have one.
808 If you have a single-CPU system with an IO-APIC, you can say Y here
809 to use it. If you say Y here even though your machine doesn't have
810 an IO-APIC, then the kernel will still run with no slowdown at all.
812 config X86_LOCAL_APIC
814 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
818 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
820 config X86_VISWS_APIC
822 depends on X86_32 && X86_VISWS
824 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
825 bool "Reroute for broken boot IRQs"
826 depends on X86_IO_APIC
828 This option enables a workaround that fixes a source of
829 spurious interrupts. This is recommended when threaded
830 interrupt handling is used on systems where the generation of
831 superfluous "boot interrupts" cannot be disabled.
833 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
834 entry in the chipset's IO-APIC is masked (as, e.g. the RT
835 kernel does during interrupt handling). On chipsets where this
836 boot IRQ generation cannot be disabled, this workaround keeps
837 the original IRQ line masked so that only the equivalent "boot
838 IRQ" is delivered to the CPUs. The workaround also tells the
839 kernel to set up the IRQ handler on the boot IRQ line. In this
840 way only one interrupt is delivered to the kernel. Otherwise
841 the spurious second interrupt may cause the kernel to bring
842 down (vital) interrupt lines.
844 Only affects "broken" chipsets. Interrupt sharing may be
845 increased on these systems.
848 bool "Machine Check / overheating reporting"
850 Machine Check support allows the processor to notify the
851 kernel if it detects a problem (e.g. overheating, data corruption).
852 The action the kernel takes depends on the severity of the problem,
853 ranging from warning messages to halting the machine.
857 prompt "Intel MCE features"
858 depends on X86_MCE && X86_LOCAL_APIC
860 Additional support for intel specific MCE features such as
865 prompt "AMD MCE features"
866 depends on X86_MCE && X86_LOCAL_APIC
868 Additional support for AMD specific MCE features such as
869 the DRAM Error Threshold.
871 config X86_ANCIENT_MCE
872 bool "Support for old Pentium 5 / WinChip machine checks"
873 depends on X86_32 && X86_MCE
875 Include support for machine check handling on old Pentium 5 or WinChip
876 systems. These typically need to be enabled explicitely on the command
879 config X86_MCE_THRESHOLD
880 depends on X86_MCE_AMD || X86_MCE_INTEL
883 config X86_MCE_INJECT
885 tristate "Machine check injector support"
887 Provide support for injecting machine checks for testing purposes.
888 If you don't know what a machine check is and you don't do kernel
889 QA it is safe to say n.
891 config X86_THERMAL_VECTOR
893 depends on X86_MCE_INTEL
896 bool "Enable VM86 support" if EXPERT
900 This option is required by programs like DOSEMU to run 16-bit legacy
901 code on X86 processors. It also may be needed by software like
902 XFree86 to initialize some video cards via BIOS. Disabling this
903 option saves about 6k.
906 tristate "Toshiba Laptop support"
909 This adds a driver to safely access the System Management Mode of
910 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
911 not work on models with a Phoenix BIOS. The System Management Mode
912 is used to set the BIOS and power saving options on Toshiba portables.
914 For information on utilities to make use of this driver see the
915 Toshiba Linux utilities web site at:
916 <http://www.buzzard.org.uk/toshiba/>.
918 Say Y if you intend to run this kernel on a Toshiba portable.
922 tristate "Dell laptop support"
924 This adds a driver to safely access the System Management Mode
925 of the CPU on the Dell Inspiron 8000. The System Management Mode
926 is used to read cpu temperature and cooling fan status and to
927 control the fans on the I8K portables.
929 This driver has been tested only on the Inspiron 8000 but it may
930 also work with other Dell laptops. You can force loading on other
931 models by passing the parameter `force=1' to the module. Use at
934 For information on utilities to make use of this driver see the
935 I8K Linux utilities web site at:
936 <http://people.debian.org/~dz/i8k/>
938 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
941 config X86_REBOOTFIXUPS
942 bool "Enable X86 board specific fixups for reboot"
945 This enables chipset and/or board specific fixups to be done
946 in order to get reboot to work correctly. This is only needed on
947 some combinations of hardware and BIOS. The symptom, for which
948 this config is intended, is when reboot ends with a stalled/hung
951 Currently, the only fixup is for the Geode machines using
952 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
954 Say Y if you want to enable the fixup. Currently, it's safe to
955 enable this option even if you don't need it.
959 tristate "/dev/cpu/microcode - microcode support"
962 If you say Y here, you will be able to update the microcode on
963 certain Intel and AMD processors. The Intel support is for the
964 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
965 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
966 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
967 You will obviously need the actual microcode binary data itself
968 which is not shipped with the Linux kernel.
970 This option selects the general module only, you need to select
971 at least one vendor specific module as well.
973 To compile this driver as a module, choose M here: the
974 module will be called microcode.
976 config MICROCODE_INTEL
977 bool "Intel microcode patch loading support"
982 This options enables microcode patch loading support for Intel
985 For latest news and information on obtaining all the required
986 Intel ingredients for this driver, check:
987 <http://www.urbanmyth.org/microcode/>.
990 bool "AMD microcode patch loading support"
994 If you select this option, microcode patch loading support for AMD
995 processors will be enabled.
997 config MICROCODE_OLD_INTERFACE
1002 tristate "/dev/cpu/*/msr - Model-specific register support"
1004 This device gives privileged processes access to the x86
1005 Model-Specific Registers (MSRs). It is a character device with
1006 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1007 MSR accesses are directed to a specific CPU on multi-processor
1011 tristate "/dev/cpu/*/cpuid - CPU information support"
1013 This device gives processes access to the x86 CPUID instruction to
1014 be executed on a specific processor. It is a character device
1015 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1019 prompt "High Memory Support"
1020 default HIGHMEM64G if X86_NUMAQ
1026 depends on !X86_NUMAQ
1028 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1029 However, the address space of 32-bit x86 processors is only 4
1030 Gigabytes large. That means that, if you have a large amount of
1031 physical memory, not all of it can be "permanently mapped" by the
1032 kernel. The physical memory that's not permanently mapped is called
1035 If you are compiling a kernel which will never run on a machine with
1036 more than 1 Gigabyte total physical RAM, answer "off" here (default
1037 choice and suitable for most users). This will result in a "3GB/1GB"
1038 split: 3GB are mapped so that each process sees a 3GB virtual memory
1039 space and the remaining part of the 4GB virtual memory space is used
1040 by the kernel to permanently map as much physical memory as
1043 If the machine has between 1 and 4 Gigabytes physical RAM, then
1046 If more than 4 Gigabytes is used then answer "64GB" here. This
1047 selection turns Intel PAE (Physical Address Extension) mode on.
1048 PAE implements 3-level paging on IA32 processors. PAE is fully
1049 supported by Linux, PAE mode is implemented on all recent Intel
1050 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1051 then the kernel will not boot on CPUs that don't support PAE!
1053 The actual amount of total physical memory will either be
1054 auto detected or can be forced by using a kernel command line option
1055 such as "mem=256M". (Try "man bootparam" or see the documentation of
1056 your boot loader (lilo or loadlin) about how to pass options to the
1057 kernel at boot time.)
1059 If unsure, say "off".
1063 depends on !X86_NUMAQ
1065 Select this if you have a 32-bit processor and between 1 and 4
1066 gigabytes of physical RAM.
1070 depends on !M386 && !M486
1073 Select this if you have a 32-bit processor and more than 4
1074 gigabytes of physical RAM.
1079 depends on EXPERIMENTAL
1080 prompt "Memory split" if EXPERT
1084 Select the desired split between kernel and user memory.
1086 If the address range available to the kernel is less than the
1087 physical memory installed, the remaining memory will be available
1088 as "high memory". Accessing high memory is a little more costly
1089 than low memory, as it needs to be mapped into the kernel first.
1090 Note that increasing the kernel address space limits the range
1091 available to user programs, making the address space there
1092 tighter. Selecting anything other than the default 3G/1G split
1093 will also likely make your kernel incompatible with binary-only
1096 If you are not absolutely sure what you are doing, leave this
1100 bool "3G/1G user/kernel split"
1101 config VMSPLIT_3G_OPT
1103 bool "3G/1G user/kernel split (for full 1G low memory)"
1105 bool "2G/2G user/kernel split"
1106 config VMSPLIT_2G_OPT
1108 bool "2G/2G user/kernel split (for full 2G low memory)"
1110 bool "1G/3G user/kernel split"
1115 default 0xB0000000 if VMSPLIT_3G_OPT
1116 default 0x80000000 if VMSPLIT_2G
1117 default 0x78000000 if VMSPLIT_2G_OPT
1118 default 0x40000000 if VMSPLIT_1G
1124 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1127 bool "PAE (Physical Address Extension) Support"
1128 depends on X86_32 && !HIGHMEM4G
1130 PAE is required for NX support, and furthermore enables
1131 larger swapspace support for non-overcommit purposes. It
1132 has the cost of more pagetable lookup overhead, and also
1133 consumes more pagetable space per process.
1135 config ARCH_PHYS_ADDR_T_64BIT
1136 def_bool X86_64 || X86_PAE
1138 config ARCH_DMA_ADDR_T_64BIT
1139 def_bool X86_64 || HIGHMEM64G
1141 config DIRECT_GBPAGES
1142 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1146 Allow the kernel linear mapping to use 1GB pages on CPUs that
1147 support it. This can improve the kernel's performance a tiny bit by
1148 reducing TLB pressure. If in doubt, say "Y".
1150 # Common NUMA Features
1152 bool "Numa Memory Allocation and Scheduler Support"
1154 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1155 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1157 Enable NUMA (Non Uniform Memory Access) support.
1159 The kernel will try to allocate memory used by a CPU on the
1160 local memory controller of the CPU and add some more
1161 NUMA awareness to the kernel.
1163 For 64-bit this is recommended if the system is Intel Core i7
1164 (or later), AMD Opteron, or EM64T NUMA.
1166 For 32-bit this is only needed on (rare) 32-bit-only platforms
1167 that support NUMA topologies, such as NUMAQ / Summit, or if you
1168 boot a 32-bit kernel on a 64-bit NUMA platform.
1170 Otherwise, you should say N.
1172 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1173 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1177 prompt "Old style AMD Opteron NUMA detection"
1178 depends on X86_64 && NUMA && PCI
1180 Enable AMD NUMA node topology detection. You should say Y here if
1181 you have a multi processor AMD system. This uses an old method to
1182 read the NUMA configuration directly from the builtin Northbridge
1183 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1184 which also takes priority if both are compiled in.
1186 config X86_64_ACPI_NUMA
1188 prompt "ACPI NUMA detection"
1189 depends on X86_64 && NUMA && ACPI && PCI
1192 Enable ACPI SRAT based node topology detection.
1194 # Some NUMA nodes have memory ranges that span
1195 # other nodes. Even though a pfn is valid and
1196 # between a node's start and end pfns, it may not
1197 # reside on that node. See memmap_init_zone()
1199 config NODES_SPAN_OTHER_NODES
1201 depends on X86_64_ACPI_NUMA
1204 bool "NUMA emulation"
1205 depends on X86_64 && NUMA
1207 Enable NUMA emulation. A flat machine will be split
1208 into virtual nodes when booted with "numa=fake=N", where N is the
1209 number of nodes. This is only useful for debugging.
1212 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1214 default "10" if MAXSMP
1215 default "6" if X86_64
1216 default "4" if X86_NUMAQ
1218 depends on NEED_MULTIPLE_NODES
1220 Specify the maximum number of NUMA Nodes available on the target
1221 system. Increases memory reserved to accommodate various tables.
1223 config HAVE_ARCH_BOOTMEM
1225 depends on X86_32 && NUMA
1227 config ARCH_HAVE_MEMORY_PRESENT
1229 depends on X86_32 && DISCONTIGMEM
1231 config NEED_NODE_MEMMAP_SIZE
1233 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1235 config HAVE_ARCH_ALLOC_REMAP
1237 depends on X86_32 && NUMA
1239 config ARCH_FLATMEM_ENABLE
1241 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1243 config ARCH_DISCONTIGMEM_ENABLE
1245 depends on NUMA && X86_32
1247 config ARCH_DISCONTIGMEM_DEFAULT
1249 depends on NUMA && X86_32
1251 config ARCH_PROC_KCORE_TEXT
1253 depends on X86_64 && PROC_KCORE
1255 config ARCH_SPARSEMEM_DEFAULT
1259 config ARCH_SPARSEMEM_ENABLE
1261 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1262 select SPARSEMEM_STATIC if X86_32
1263 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1265 config ARCH_SELECT_MEMORY_MODEL
1267 depends on ARCH_SPARSEMEM_ENABLE
1269 config ARCH_MEMORY_PROBE
1271 depends on MEMORY_HOTPLUG
1273 config ILLEGAL_POINTER_VALUE
1276 default 0xdead000000000000 if X86_64
1281 bool "Allocate 3rd-level pagetables from highmem"
1284 The VM uses one page table entry for each page of physical memory.
1285 For systems with a lot of RAM, this can be wasteful of precious
1286 low memory. Setting this option will put user-space page table
1287 entries in high memory.
1289 config X86_CHECK_BIOS_CORRUPTION
1290 bool "Check for low memory corruption"
1292 Periodically check for memory corruption in low memory, which
1293 is suspected to be caused by BIOS. Even when enabled in the
1294 configuration, it is disabled at runtime. Enable it by
1295 setting "memory_corruption_check=1" on the kernel command
1296 line. By default it scans the low 64k of memory every 60
1297 seconds; see the memory_corruption_check_size and
1298 memory_corruption_check_period parameters in
1299 Documentation/kernel-parameters.txt to adjust this.
1301 When enabled with the default parameters, this option has
1302 almost no overhead, as it reserves a relatively small amount
1303 of memory and scans it infrequently. It both detects corruption
1304 and prevents it from affecting the running system.
1306 It is, however, intended as a diagnostic tool; if repeatable
1307 BIOS-originated corruption always affects the same memory,
1308 you can use memmap= to prevent the kernel from using that
1311 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1312 bool "Set the default setting of memory_corruption_check"
1313 depends on X86_CHECK_BIOS_CORRUPTION
1316 Set whether the default state of memory_corruption_check is
1319 config X86_RESERVE_LOW
1320 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1324 Specify the amount of low memory to reserve for the BIOS.
1326 The first page contains BIOS data structures that the kernel
1327 must not use, so that page must always be reserved.
1329 By default we reserve the first 64K of physical RAM, as a
1330 number of BIOSes are known to corrupt that memory range
1331 during events such as suspend/resume or monitor cable
1332 insertion, so it must not be used by the kernel.
1334 You can set this to 4 if you are absolutely sure that you
1335 trust the BIOS to get all its memory reservations and usages
1336 right. If you know your BIOS have problems beyond the
1337 default 64K area, you can set this to 640 to avoid using the
1338 entire low memory range.
1340 If you have doubts about the BIOS (e.g. suspend/resume does
1341 not work or there's kernel crashes after certain hardware
1342 hotplug events) then you might want to enable
1343 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1344 typical corruption patterns.
1346 Leave this to the default value of 64 if you are unsure.
1348 config MATH_EMULATION
1350 prompt "Math emulation" if X86_32
1352 Linux can emulate a math coprocessor (used for floating point
1353 operations) if you don't have one. 486DX and Pentium processors have
1354 a math coprocessor built in, 486SX and 386 do not, unless you added
1355 a 487DX or 387, respectively. (The messages during boot time can
1356 give you some hints here ["man dmesg"].) Everyone needs either a
1357 coprocessor or this emulation.
1359 If you don't have a math coprocessor, you need to say Y here; if you
1360 say Y here even though you have a coprocessor, the coprocessor will
1361 be used nevertheless. (This behavior can be changed with the kernel
1362 command line option "no387", which comes handy if your coprocessor
1363 is broken. Try "man bootparam" or see the documentation of your boot
1364 loader (lilo or loadlin) about how to pass options to the kernel at
1365 boot time.) This means that it is a good idea to say Y here if you
1366 intend to use this kernel on different machines.
1368 More information about the internals of the Linux math coprocessor
1369 emulation can be found in <file:arch/x86/math-emu/README>.
1371 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1372 kernel, it won't hurt.
1376 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1378 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1379 the Memory Type Range Registers (MTRRs) may be used to control
1380 processor access to memory ranges. This is most useful if you have
1381 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1382 allows bus write transfers to be combined into a larger transfer
1383 before bursting over the PCI/AGP bus. This can increase performance
1384 of image write operations 2.5 times or more. Saying Y here creates a
1385 /proc/mtrr file which may be used to manipulate your processor's
1386 MTRRs. Typically the X server should use this.
1388 This code has a reasonably generic interface so that similar
1389 control registers on other processors can be easily supported
1392 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1393 Registers (ARRs) which provide a similar functionality to MTRRs. For
1394 these, the ARRs are used to emulate the MTRRs.
1395 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1396 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1397 write-combining. All of these processors are supported by this code
1398 and it makes sense to say Y here if you have one of them.
1400 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1401 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1402 can lead to all sorts of problems, so it's good to say Y here.
1404 You can safely say Y even if your machine doesn't have MTRRs, you'll
1405 just add about 9 KB to your kernel.
1407 See <file:Documentation/x86/mtrr.txt> for more information.
1409 config MTRR_SANITIZER
1411 prompt "MTRR cleanup support"
1414 Convert MTRR layout from continuous to discrete, so X drivers can
1415 add writeback entries.
1417 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1418 The largest mtrr entry size for a continuous block can be set with
1423 config MTRR_SANITIZER_ENABLE_DEFAULT
1424 int "MTRR cleanup enable value (0-1)"
1427 depends on MTRR_SANITIZER
1429 Enable mtrr cleanup default value
1431 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1432 int "MTRR cleanup spare reg num (0-7)"
1435 depends on MTRR_SANITIZER
1437 mtrr cleanup spare entries default, it can be changed via
1438 mtrr_spare_reg_nr=N on the kernel command line.
1442 prompt "x86 PAT support" if EXPERT
1445 Use PAT attributes to setup page level cache control.
1447 PATs are the modern equivalents of MTRRs and are much more
1448 flexible than MTRRs.
1450 Say N here if you see bootup problems (boot crash, boot hang,
1451 spontaneous reboots) or a non-working video driver.
1455 config ARCH_USES_PG_UNCACHED
1460 bool "EFI runtime service support"
1463 This enables the kernel to use EFI runtime services that are
1464 available (such as the EFI variable services).
1466 This option is only useful on systems that have EFI firmware.
1467 In addition, you should use the latest ELILO loader available
1468 at <http://elilo.sourceforge.net> in order to take advantage
1469 of EFI runtime services. However, even with this option, the
1470 resultant kernel should continue to boot on existing non-EFI
1475 prompt "Enable seccomp to safely compute untrusted bytecode"
1477 This kernel feature is useful for number crunching applications
1478 that may need to compute untrusted bytecode during their
1479 execution. By using pipes or other transports made available to
1480 the process as file descriptors supporting the read/write
1481 syscalls, it's possible to isolate those applications in
1482 their own address space using seccomp. Once seccomp is
1483 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1484 and the task is only allowed to execute a few safe syscalls
1485 defined by each seccomp mode.
1487 If unsure, say Y. Only embedded should say N here.
1489 config CC_STACKPROTECTOR
1490 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1492 This option turns on the -fstack-protector GCC feature. This
1493 feature puts, at the beginning of functions, a canary value on
1494 the stack just before the return address, and validates
1495 the value just before actually returning. Stack based buffer
1496 overflows (that need to overwrite this return address) now also
1497 overwrite the canary, which gets detected and the attack is then
1498 neutralized via a kernel panic.
1500 This feature requires gcc version 4.2 or above, or a distribution
1501 gcc with the feature backported. Older versions are automatically
1502 detected and for those versions, this configuration option is
1503 ignored. (and a warning is printed during bootup)
1505 source kernel/Kconfig.hz
1508 bool "kexec system call"
1510 kexec is a system call that implements the ability to shutdown your
1511 current kernel, and to start another kernel. It is like a reboot
1512 but it is independent of the system firmware. And like a reboot
1513 you can start any kernel with it, not just Linux.
1515 The name comes from the similarity to the exec system call.
1517 It is an ongoing process to be certain the hardware in a machine
1518 is properly shutdown, so do not be surprised if this code does not
1519 initially work for you. It may help to enable device hotplugging
1520 support. As of this writing the exact hardware interface is
1521 strongly in flux, so no good recommendation can be made.
1524 bool "kernel crash dumps"
1525 depends on X86_64 || (X86_32 && HIGHMEM)
1527 Generate crash dump after being started by kexec.
1528 This should be normally only set in special crash dump kernels
1529 which are loaded in the main kernel with kexec-tools into
1530 a specially reserved region and then later executed after
1531 a crash by kdump/kexec. The crash dump kernel must be compiled
1532 to a memory address not used by the main kernel or BIOS using
1533 PHYSICAL_START, or it must be built as a relocatable image
1534 (CONFIG_RELOCATABLE=y).
1535 For more details see Documentation/kdump/kdump.txt
1538 bool "kexec jump (EXPERIMENTAL)"
1539 depends on EXPERIMENTAL
1540 depends on KEXEC && HIBERNATION
1542 Jump between original kernel and kexeced kernel and invoke
1543 code in physical address mode via KEXEC
1545 config PHYSICAL_START
1546 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1549 This gives the physical address where the kernel is loaded.
1551 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1552 bzImage will decompress itself to above physical address and
1553 run from there. Otherwise, bzImage will run from the address where
1554 it has been loaded by the boot loader and will ignore above physical
1557 In normal kdump cases one does not have to set/change this option
1558 as now bzImage can be compiled as a completely relocatable image
1559 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1560 address. This option is mainly useful for the folks who don't want
1561 to use a bzImage for capturing the crash dump and want to use a
1562 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1563 to be specifically compiled to run from a specific memory area
1564 (normally a reserved region) and this option comes handy.
1566 So if you are using bzImage for capturing the crash dump,
1567 leave the value here unchanged to 0x1000000 and set
1568 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1569 for capturing the crash dump change this value to start of
1570 the reserved region. In other words, it can be set based on
1571 the "X" value as specified in the "crashkernel=YM@XM"
1572 command line boot parameter passed to the panic-ed
1573 kernel. Please take a look at Documentation/kdump/kdump.txt
1574 for more details about crash dumps.
1576 Usage of bzImage for capturing the crash dump is recommended as
1577 one does not have to build two kernels. Same kernel can be used
1578 as production kernel and capture kernel. Above option should have
1579 gone away after relocatable bzImage support is introduced. But it
1580 is present because there are users out there who continue to use
1581 vmlinux for dump capture. This option should go away down the
1584 Don't change this unless you know what you are doing.
1587 bool "Build a relocatable kernel"
1590 This builds a kernel image that retains relocation information
1591 so it can be loaded someplace besides the default 1MB.
1592 The relocations tend to make the kernel binary about 10% larger,
1593 but are discarded at runtime.
1595 One use is for the kexec on panic case where the recovery kernel
1596 must live at a different physical address than the primary
1599 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1600 it has been loaded at and the compile time physical address
1601 (CONFIG_PHYSICAL_START) is ignored.
1603 # Relocation on x86-32 needs some additional build support
1604 config X86_NEED_RELOCS
1606 depends on X86_32 && RELOCATABLE
1608 config PHYSICAL_ALIGN
1609 hex "Alignment value to which kernel should be aligned" if X86_32
1611 range 0x2000 0x1000000
1613 This value puts the alignment restrictions on physical address
1614 where kernel is loaded and run from. Kernel is compiled for an
1615 address which meets above alignment restriction.
1617 If bootloader loads the kernel at a non-aligned address and
1618 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1619 address aligned to above value and run from there.
1621 If bootloader loads the kernel at a non-aligned address and
1622 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1623 load address and decompress itself to the address it has been
1624 compiled for and run from there. The address for which kernel is
1625 compiled already meets above alignment restrictions. Hence the
1626 end result is that kernel runs from a physical address meeting
1627 above alignment restrictions.
1629 Don't change this unless you know what you are doing.
1632 bool "Support for hot-pluggable CPUs"
1633 depends on SMP && HOTPLUG
1635 Say Y here to allow turning CPUs off and on. CPUs can be
1636 controlled through /sys/devices/system/cpu.
1637 ( Note: power management support will enable this option
1638 automatically on SMP systems. )
1639 Say N if you want to disable CPU hotplug.
1643 prompt "Compat VDSO support"
1644 depends on X86_32 || IA32_EMULATION
1646 Map the 32-bit VDSO to the predictable old-style address too.
1648 Say N here if you are running a sufficiently recent glibc
1649 version (2.3.3 or later), to remove the high-mapped
1650 VDSO mapping and to exclusively use the randomized VDSO.
1655 bool "Built-in kernel command line"
1657 Allow for specifying boot arguments to the kernel at
1658 build time. On some systems (e.g. embedded ones), it is
1659 necessary or convenient to provide some or all of the
1660 kernel boot arguments with the kernel itself (that is,
1661 to not rely on the boot loader to provide them.)
1663 To compile command line arguments into the kernel,
1664 set this option to 'Y', then fill in the
1665 the boot arguments in CONFIG_CMDLINE.
1667 Systems with fully functional boot loaders (i.e. non-embedded)
1668 should leave this option set to 'N'.
1671 string "Built-in kernel command string"
1672 depends on CMDLINE_BOOL
1675 Enter arguments here that should be compiled into the kernel
1676 image and used at boot time. If the boot loader provides a
1677 command line at boot time, it is appended to this string to
1678 form the full kernel command line, when the system boots.
1680 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1681 change this behavior.
1683 In most cases, the command line (whether built-in or provided
1684 by the boot loader) should specify the device for the root
1687 config CMDLINE_OVERRIDE
1688 bool "Built-in command line overrides boot loader arguments"
1689 depends on CMDLINE_BOOL
1691 Set this option to 'Y' to have the kernel ignore the boot loader
1692 command line, and use ONLY the built-in command line.
1694 This is used to work around broken boot loaders. This should
1695 be set to 'N' under normal conditions.
1699 config ARCH_ENABLE_MEMORY_HOTPLUG
1701 depends on X86_64 || (X86_32 && HIGHMEM)
1703 config ARCH_ENABLE_MEMORY_HOTREMOVE
1705 depends on MEMORY_HOTPLUG
1707 config HAVE_ARCH_EARLY_PFN_TO_NID
1711 config USE_PERCPU_NUMA_NODE_ID
1715 menu "Power management and ACPI options"
1717 config ARCH_HIBERNATION_HEADER
1719 depends on X86_64 && HIBERNATION
1721 source "kernel/power/Kconfig"
1723 source "drivers/acpi/Kconfig"
1725 source "drivers/sfi/Kconfig"
1729 depends on APM || APM_MODULE
1732 tristate "APM (Advanced Power Management) BIOS support"
1733 depends on X86_32 && PM_SLEEP
1735 APM is a BIOS specification for saving power using several different
1736 techniques. This is mostly useful for battery powered laptops with
1737 APM compliant BIOSes. If you say Y here, the system time will be
1738 reset after a RESUME operation, the /proc/apm device will provide
1739 battery status information, and user-space programs will receive
1740 notification of APM "events" (e.g. battery status change).
1742 If you select "Y" here, you can disable actual use of the APM
1743 BIOS by passing the "apm=off" option to the kernel at boot time.
1745 Note that the APM support is almost completely disabled for
1746 machines with more than one CPU.
1748 In order to use APM, you will need supporting software. For location
1749 and more information, read <file:Documentation/power/pm.txt> and the
1750 Battery Powered Linux mini-HOWTO, available from
1751 <http://www.tldp.org/docs.html#howto>.
1753 This driver does not spin down disk drives (see the hdparm(8)
1754 manpage ("man 8 hdparm") for that), and it doesn't turn off
1755 VESA-compliant "green" monitors.
1757 This driver does not support the TI 4000M TravelMate and the ACER
1758 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1759 desktop machines also don't have compliant BIOSes, and this driver
1760 may cause those machines to panic during the boot phase.
1762 Generally, if you don't have a battery in your machine, there isn't
1763 much point in using this driver and you should say N. If you get
1764 random kernel OOPSes or reboots that don't seem to be related to
1765 anything, try disabling/enabling this option (or disabling/enabling
1768 Some other things you should try when experiencing seemingly random,
1771 1) make sure that you have enough swap space and that it is
1773 2) pass the "no-hlt" option to the kernel
1774 3) switch on floating point emulation in the kernel and pass
1775 the "no387" option to the kernel
1776 4) pass the "floppy=nodma" option to the kernel
1777 5) pass the "mem=4M" option to the kernel (thereby disabling
1778 all but the first 4 MB of RAM)
1779 6) make sure that the CPU is not over clocked.
1780 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1781 8) disable the cache from your BIOS settings
1782 9) install a fan for the video card or exchange video RAM
1783 10) install a better fan for the CPU
1784 11) exchange RAM chips
1785 12) exchange the motherboard.
1787 To compile this driver as a module, choose M here: the
1788 module will be called apm.
1792 config APM_IGNORE_USER_SUSPEND
1793 bool "Ignore USER SUSPEND"
1795 This option will ignore USER SUSPEND requests. On machines with a
1796 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1797 series notebooks, it is necessary to say Y because of a BIOS bug.
1799 config APM_DO_ENABLE
1800 bool "Enable PM at boot time"
1802 Enable APM features at boot time. From page 36 of the APM BIOS
1803 specification: "When disabled, the APM BIOS does not automatically
1804 power manage devices, enter the Standby State, enter the Suspend
1805 State, or take power saving steps in response to CPU Idle calls."
1806 This driver will make CPU Idle calls when Linux is idle (unless this
1807 feature is turned off -- see "Do CPU IDLE calls", below). This
1808 should always save battery power, but more complicated APM features
1809 will be dependent on your BIOS implementation. You may need to turn
1810 this option off if your computer hangs at boot time when using APM
1811 support, or if it beeps continuously instead of suspending. Turn
1812 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1813 T400CDT. This is off by default since most machines do fine without
1817 bool "Make CPU Idle calls when idle"
1819 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1820 On some machines, this can activate improved power savings, such as
1821 a slowed CPU clock rate, when the machine is idle. These idle calls
1822 are made after the idle loop has run for some length of time (e.g.,
1823 333 mS). On some machines, this will cause a hang at boot time or
1824 whenever the CPU becomes idle. (On machines with more than one CPU,
1825 this option does nothing.)
1827 config APM_DISPLAY_BLANK
1828 bool "Enable console blanking using APM"
1830 Enable console blanking using the APM. Some laptops can use this to
1831 turn off the LCD backlight when the screen blanker of the Linux
1832 virtual console blanks the screen. Note that this is only used by
1833 the virtual console screen blanker, and won't turn off the backlight
1834 when using the X Window system. This also doesn't have anything to
1835 do with your VESA-compliant power-saving monitor. Further, this
1836 option doesn't work for all laptops -- it might not turn off your
1837 backlight at all, or it might print a lot of errors to the console,
1838 especially if you are using gpm.
1840 config APM_ALLOW_INTS
1841 bool "Allow interrupts during APM BIOS calls"
1843 Normally we disable external interrupts while we are making calls to
1844 the APM BIOS as a measure to lessen the effects of a badly behaving
1845 BIOS implementation. The BIOS should reenable interrupts if it
1846 needs to. Unfortunately, some BIOSes do not -- especially those in
1847 many of the newer IBM Thinkpads. If you experience hangs when you
1848 suspend, try setting this to Y. Otherwise, say N.
1852 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1854 source "drivers/cpuidle/Kconfig"
1856 source "drivers/idle/Kconfig"
1861 menu "Bus options (PCI etc.)"
1866 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1868 Find out whether you have a PCI motherboard. PCI is the name of a
1869 bus system, i.e. the way the CPU talks to the other stuff inside
1870 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1871 VESA. If you have PCI, say Y, otherwise N.
1874 prompt "PCI access mode"
1875 depends on X86_32 && PCI
1878 On PCI systems, the BIOS can be used to detect the PCI devices and
1879 determine their configuration. However, some old PCI motherboards
1880 have BIOS bugs and may crash if this is done. Also, some embedded
1881 PCI-based systems don't have any BIOS at all. Linux can also try to
1882 detect the PCI hardware directly without using the BIOS.
1884 With this option, you can specify how Linux should detect the
1885 PCI devices. If you choose "BIOS", the BIOS will be used,
1886 if you choose "Direct", the BIOS won't be used, and if you
1887 choose "MMConfig", then PCI Express MMCONFIG will be used.
1888 If you choose "Any", the kernel will try MMCONFIG, then the
1889 direct access method and falls back to the BIOS if that doesn't
1890 work. If unsure, go with the default, which is "Any".
1895 config PCI_GOMMCONFIG
1912 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1914 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1917 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1921 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1925 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1929 depends on PCI && XEN
1937 bool "Support mmconfig PCI config space access"
1938 depends on X86_64 && PCI && ACPI
1940 config PCI_CNB20LE_QUIRK
1941 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1943 depends on PCI && EXPERIMENTAL
1945 Read the PCI windows out of the CNB20LE host bridge. This allows
1946 PCI hotplug to work on systems with the CNB20LE chipset which do
1949 There's no public spec for this chipset, and this functionality
1950 is known to be incomplete.
1952 You should say N unless you know you need this.
1955 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1956 depends on PCI_MSI && ACPI && EXPERIMENTAL
1958 DMA remapping (DMAR) devices support enables independent address
1959 translations for Direct Memory Access (DMA) from devices.
1960 These DMA remapping devices are reported via ACPI tables
1961 and include PCI device scope covered by these DMA
1964 config DMAR_DEFAULT_ON
1966 prompt "Enable DMA Remapping Devices by default"
1969 Selecting this option will enable a DMAR device at boot time if
1970 one is found. If this option is not selected, DMAR support can
1971 be enabled by passing intel_iommu=on to the kernel. It is
1972 recommended you say N here while the DMAR code remains
1975 config DMAR_BROKEN_GFX_WA
1976 bool "Workaround broken graphics drivers (going away soon)"
1977 depends on DMAR && BROKEN
1979 Current Graphics drivers tend to use physical address
1980 for DMA and avoid using DMA APIs. Setting this config
1981 option permits the IOMMU driver to set a unity map for
1982 all the OS-visible memory. Hence the driver can continue
1983 to use physical addresses for DMA, at least until this
1984 option is removed in the 2.6.32 kernel.
1986 config DMAR_FLOPPY_WA
1990 Floppy disk drivers are known to bypass DMA API calls
1991 thereby failing to work when IOMMU is enabled. This
1992 workaround will setup a 1:1 mapping for the first
1993 16MiB to make floppy (an ISA device) work.
1996 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1997 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1999 Supports Interrupt remapping for IO-APIC and MSI devices.
2000 To use x2apic mode in the CPU's which support x2APIC enhancements or
2001 to support platforms with CPU's having > 8 bit APIC ID, say Y.
2003 source "drivers/pci/pcie/Kconfig"
2005 source "drivers/pci/Kconfig"
2007 # x86_64 have no ISA slots, but do have ISA-style DMA.
2016 Find out whether you have ISA slots on your motherboard. ISA is the
2017 name of a bus system, i.e. the way the CPU talks to the other stuff
2018 inside your box. Other bus systems are PCI, EISA, MicroChannel
2019 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2020 newer boards don't support it. If you have ISA, say Y, otherwise N.
2026 The Extended Industry Standard Architecture (EISA) bus was
2027 developed as an open alternative to the IBM MicroChannel bus.
2029 The EISA bus provided some of the features of the IBM MicroChannel
2030 bus while maintaining backward compatibility with cards made for
2031 the older ISA bus. The EISA bus saw limited use between 1988 and
2032 1995 when it was made obsolete by the PCI bus.
2034 Say Y here if you are building a kernel for an EISA-based machine.
2038 source "drivers/eisa/Kconfig"
2043 MicroChannel Architecture is found in some IBM PS/2 machines and
2044 laptops. It is a bus system similar to PCI or ISA. See
2045 <file:Documentation/mca.txt> (and especially the web page given
2046 there) before attempting to build an MCA bus kernel.
2048 source "drivers/mca/Kconfig"
2051 tristate "NatSemi SCx200 support"
2053 This provides basic support for National Semiconductor's
2054 (now AMD's) Geode processors. The driver probes for the
2055 PCI-IDs of several on-chip devices, so its a good dependency
2056 for other scx200_* drivers.
2058 If compiled as a module, the driver is named scx200.
2060 config SCx200HR_TIMER
2061 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2065 This driver provides a clocksource built upon the on-chip
2066 27MHz high-resolution timer. Its also a workaround for
2067 NSC Geode SC-1100's buggy TSC, which loses time when the
2068 processor goes idle (as is done by the scheduler). The
2069 other workaround is idle=poll boot option.
2072 bool "One Laptop Per Child support"
2074 select OLPC_OPENFIRMWARE
2075 depends on !X86_64 && !X86_PAE
2077 Add support for detecting the unique features of the OLPC
2081 tristate "OLPC XO-1 support"
2082 depends on OLPC && MFD_CS5535
2084 Add support for non-essential features of the OLPC XO-1 laptop.
2086 config OLPC_OPENFIRMWARE
2087 bool "Support for OLPC's Open Firmware"
2088 depends on !X86_64 && !X86_PAE
2092 This option adds support for the implementation of Open Firmware
2093 that is used on the OLPC XO-1 Children's Machine.
2094 If unsure, say N here.
2096 config OLPC_OPENFIRMWARE_DT
2098 default y if OLPC_OPENFIRMWARE && PROC_DEVICETREE
2105 depends on CPU_SUP_AMD && PCI
2107 source "drivers/pcmcia/Kconfig"
2109 source "drivers/pci/hotplug/Kconfig"
2114 menu "Executable file formats / Emulations"
2116 source "fs/Kconfig.binfmt"
2118 config IA32_EMULATION
2119 bool "IA32 Emulation"
2121 select COMPAT_BINFMT_ELF
2123 Include code to run 32-bit programs under a 64-bit kernel. You should
2124 likely turn this on, unless you're 100% sure that you don't have any
2125 32-bit programs left.
2128 tristate "IA32 a.out support"
2129 depends on IA32_EMULATION
2131 Support old a.out binaries in the 32bit emulation.
2135 depends on IA32_EMULATION
2137 config COMPAT_FOR_U64_ALIGNMENT
2141 config SYSVIPC_COMPAT
2143 depends on COMPAT && SYSVIPC
2148 config HAVE_ATOMIC_IOMAP
2152 config HAVE_TEXT_POKE_SMP
2154 select STOP_MACHINE if SMP
2156 source "net/Kconfig"
2158 source "drivers/Kconfig"
2160 source "drivers/firmware/Kconfig"
2164 source "arch/x86/Kconfig.debug"
2166 source "security/Kconfig"
2168 source "crypto/Kconfig"
2170 source "arch/x86/kvm/Kconfig"
2172 source "lib/Kconfig"