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 OF_EARLY_FLATTREE
392 Select for the Intel CE media processor (CE4100) SOC.
393 This option compiles in support for the CE4100 SOC for settop
394 boxes and media devices.
397 bool "Moorestown MID platform"
401 depends on X86_EXTENDED_PLATFORM
402 depends on X86_IO_APIC
407 select X86_PLATFORM_DEVICES
409 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
410 Internet Device(MID) platform. Moorestown consists of two chips:
411 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
412 Unlike standard x86 PCs, Moorestown does not have many legacy devices
413 nor standard legacy replacement devices/features. e.g. Moorestown does
414 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
417 bool "RDC R-321x SoC"
419 depends on X86_EXTENDED_PLATFORM
421 select X86_REBOOTFIXUPS
423 This option is needed for RDC R-321x system-on-chip, also known
425 If you don't have one of these chips, you should say N here.
427 config X86_32_NON_STANDARD
428 bool "Support non-standard 32-bit SMP architectures"
429 depends on X86_32 && SMP
430 depends on X86_EXTENDED_PLATFORM
432 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
433 subarchitectures. It is intended for a generic binary kernel.
434 if you select them all, kernel will probe it one by one. and will
437 # Alphabetically sorted list of Non standard 32 bit platforms
440 bool "NUMAQ (IBM/Sequent)"
441 depends on X86_32_NON_STANDARD
446 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
447 NUMA multiquad box. This changes the way that processors are
448 bootstrapped, and uses Clustered Logical APIC addressing mode instead
449 of Flat Logical. You will need a new lynxer.elf file to flash your
450 firmware with - send email to <Martin.Bligh@us.ibm.com>.
452 config X86_SUPPORTS_MEMORY_FAILURE
454 # MCE code calls memory_failure():
456 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
457 depends on !X86_NUMAQ
458 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
459 depends on X86_64 || !SPARSEMEM
460 select ARCH_SUPPORTS_MEMORY_FAILURE
463 bool "SGI 320/540 (Visual Workstation)"
464 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
465 depends on X86_32_NON_STANDARD
467 The SGI Visual Workstation series is an IA32-based workstation
468 based on SGI systems chips with some legacy PC hardware attached.
470 Say Y here to create a kernel to run on the SGI 320 or 540.
472 A kernel compiled for the Visual Workstation will run on general
473 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
476 bool "Summit/EXA (IBM x440)"
477 depends on X86_32_NON_STANDARD
479 This option is needed for IBM systems that use the Summit/EXA chipset.
480 In particular, it is needed for the x440.
483 bool "Unisys ES7000 IA32 series"
484 depends on X86_32_NON_STANDARD && X86_BIGSMP
486 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
487 supposed to run on an IA32-based Unisys ES7000 system.
490 tristate "Eurobraille/Iris poweroff module"
493 The Iris machines from EuroBraille do not have APM or ACPI support
494 to shut themselves down properly. A special I/O sequence is
495 needed to do so, which is what this module does at
498 This is only for Iris machines from EuroBraille.
502 config SCHED_OMIT_FRAME_POINTER
504 prompt "Single-depth WCHAN output"
507 Calculate simpler /proc/<PID>/wchan values. If this option
508 is disabled then wchan values will recurse back to the
509 caller function. This provides more accurate wchan values,
510 at the expense of slightly more scheduling overhead.
512 If in doubt, say "Y".
514 menuconfig PARAVIRT_GUEST
515 bool "Paravirtualized guest support"
517 Say Y here to get to see options related to running Linux under
518 various hypervisors. This option alone does not add any kernel code.
520 If you say N, all options in this submenu will be skipped and disabled.
524 source "arch/x86/xen/Kconfig"
527 bool "KVM paravirtualized clock"
529 select PARAVIRT_CLOCK
531 Turning on this option will allow you to run a paravirtualized clock
532 when running over the KVM hypervisor. Instead of relying on a PIT
533 (or probably other) emulation by the underlying device model, the host
534 provides the guest with timing infrastructure such as time of day, and
538 bool "KVM Guest support"
541 This option enables various optimizations for running under the KVM
544 source "arch/x86/lguest/Kconfig"
547 bool "Enable paravirtualization code"
549 This changes the kernel so it can modify itself when it is run
550 under a hypervisor, potentially improving performance significantly
551 over full virtualization. However, when run without a hypervisor
552 the kernel is theoretically slower and slightly larger.
554 config PARAVIRT_SPINLOCKS
555 bool "Paravirtualization layer for spinlocks"
556 depends on PARAVIRT && SMP && EXPERIMENTAL
558 Paravirtualized spinlocks allow a pvops backend to replace the
559 spinlock implementation with something virtualization-friendly
560 (for example, block the virtual CPU rather than spinning).
562 Unfortunately the downside is an up to 5% performance hit on
563 native kernels, with various workloads.
565 If you are unsure how to answer this question, answer N.
567 config PARAVIRT_CLOCK
572 config PARAVIRT_DEBUG
573 bool "paravirt-ops debugging"
574 depends on PARAVIRT && DEBUG_KERNEL
576 Enable to debug paravirt_ops internals. Specifically, BUG if
577 a paravirt_op is missing when it is called.
585 This option adds a kernel parameter 'memtest', which allows memtest
587 memtest=0, mean disabled; -- default
588 memtest=1, mean do 1 test pattern;
590 memtest=4, mean do 4 test patterns.
591 If you are unsure how to answer this question, answer N.
593 config X86_SUMMIT_NUMA
595 depends on X86_32 && NUMA && X86_32_NON_STANDARD
597 config X86_CYCLONE_TIMER
599 depends on X86_32_NON_STANDARD
601 source "arch/x86/Kconfig.cpu"
605 prompt "HPET Timer Support" if X86_32
607 Use the IA-PC HPET (High Precision Event Timer) to manage
608 time in preference to the PIT and RTC, if a HPET is
610 HPET is the next generation timer replacing legacy 8254s.
611 The HPET provides a stable time base on SMP
612 systems, unlike the TSC, but it is more expensive to access,
613 as it is off-chip. You can find the HPET spec at
614 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
616 You can safely choose Y here. However, HPET will only be
617 activated if the platform and the BIOS support this feature.
618 Otherwise the 8254 will be used for timing services.
620 Choose N to continue using the legacy 8254 timer.
622 config HPET_EMULATE_RTC
624 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
628 prompt "Langwell APB Timer Support" if X86_MRST
630 APB timer is the replacement for 8254, HPET on X86 MID platforms.
631 The APBT provides a stable time base on SMP
632 systems, unlike the TSC, but it is more expensive to access,
633 as it is off-chip. APB timers are always running regardless of CPU
634 C states, they are used as per CPU clockevent device when possible.
636 # Mark as expert because too many people got it wrong.
637 # The code disables itself when not needed.
640 bool "Enable DMI scanning" if EXPERT
642 Enabled scanning of DMI to identify machine quirks. Say Y
643 here unless you have verified that your setup is not
644 affected by entries in the DMI blacklist. Required by PNP
648 bool "GART IOMMU support" if EXPERT
651 depends on X86_64 && PCI && AMD_NB
653 Support for full DMA access of devices with 32bit memory access only
654 on systems with more than 3GB. This is usually needed for USB,
655 sound, many IDE/SATA chipsets and some other devices.
656 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
657 based hardware IOMMU and a software bounce buffer based IOMMU used
658 on Intel systems and as fallback.
659 The code is only active when needed (enough memory and limited
660 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
664 bool "IBM Calgary IOMMU support"
666 depends on X86_64 && PCI && EXPERIMENTAL
668 Support for hardware IOMMUs in IBM's xSeries x366 and x460
669 systems. Needed to run systems with more than 3GB of memory
670 properly with 32-bit PCI devices that do not support DAC
671 (Double Address Cycle). Calgary also supports bus level
672 isolation, where all DMAs pass through the IOMMU. This
673 prevents them from going anywhere except their intended
674 destination. This catches hard-to-find kernel bugs and
675 mis-behaving drivers and devices that do not use the DMA-API
676 properly to set up their DMA buffers. The IOMMU can be
677 turned off at boot time with the iommu=off parameter.
678 Normally the kernel will make the right choice by itself.
681 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
683 prompt "Should Calgary be enabled by default?"
684 depends on CALGARY_IOMMU
686 Should Calgary be enabled by default? if you choose 'y', Calgary
687 will be used (if it exists). If you choose 'n', Calgary will not be
688 used even if it exists. If you choose 'n' and would like to use
689 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
693 bool "AMD IOMMU support"
696 depends on X86_64 && PCI && ACPI
698 With this option you can enable support for AMD IOMMU hardware in
699 your system. An IOMMU is a hardware component which provides
700 remapping of DMA memory accesses from devices. With an AMD IOMMU you
701 can isolate the the DMA memory of different devices and protect the
702 system from misbehaving device drivers or hardware.
704 You can find out if your system has an AMD IOMMU if you look into
705 your BIOS for an option to enable it or if you have an IVRS ACPI
708 config AMD_IOMMU_STATS
709 bool "Export AMD IOMMU statistics to debugfs"
713 This option enables code in the AMD IOMMU driver to collect various
714 statistics about whats happening in the driver and exports that
715 information to userspace via debugfs.
718 # need this always selected by IOMMU for the VIA workaround
722 Support for software bounce buffers used on x86-64 systems
723 which don't have a hardware IOMMU (e.g. the current generation
724 of Intel's x86-64 CPUs). Using this PCI devices which can only
725 access 32-bits of memory can be used on systems with more than
726 3 GB of memory. If unsure, say Y.
729 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
732 def_bool (AMD_IOMMU || DMAR)
735 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
736 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
737 select CPUMASK_OFFSTACK
739 Enable maximum number of CPUS and NUMA Nodes for this architecture.
743 int "Maximum number of CPUs" if SMP && !MAXSMP
744 range 2 8 if SMP && X86_32 && !X86_BIGSMP
745 range 2 512 if SMP && !MAXSMP
747 default "4096" if MAXSMP
748 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
751 This allows you to specify the maximum number of CPUs which this
752 kernel will support. The maximum supported value is 512 and the
753 minimum value which makes sense is 2.
755 This is purely to save memory - each supported CPU adds
756 approximately eight kilobytes to the kernel image.
759 bool "SMT (Hyperthreading) scheduler support"
762 SMT scheduler support improves the CPU scheduler's decision making
763 when dealing with Intel Pentium 4 chips with HyperThreading at a
764 cost of slightly increased overhead in some places. If unsure say
769 prompt "Multi-core scheduler support"
772 Multi-core scheduler support improves the CPU scheduler's decision
773 making when dealing with multi-core CPU chips at a cost of slightly
774 increased overhead in some places. If unsure say N here.
776 config IRQ_TIME_ACCOUNTING
777 bool "Fine granularity task level IRQ time accounting"
780 Select this option to enable fine granularity task irq time
781 accounting. This is done by reading a timestamp on each
782 transitions between softirq and hardirq state, so there can be a
783 small performance impact.
785 If in doubt, say N here.
787 source "kernel/Kconfig.preempt"
790 bool "Local APIC support on uniprocessors"
791 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
793 A local APIC (Advanced Programmable Interrupt Controller) is an
794 integrated interrupt controller in the CPU. If you have a single-CPU
795 system which has a processor with a local APIC, you can say Y here to
796 enable and use it. If you say Y here even though your machine doesn't
797 have a local APIC, then the kernel will still run with no slowdown at
798 all. The local APIC supports CPU-generated self-interrupts (timer,
799 performance counters), and the NMI watchdog which detects hard
803 bool "IO-APIC support on uniprocessors"
804 depends on X86_UP_APIC
806 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
807 SMP-capable replacement for PC-style interrupt controllers. Most
808 SMP systems and many recent uniprocessor systems have one.
810 If you have a single-CPU system with an IO-APIC, you can say Y here
811 to use it. If you say Y here even though your machine doesn't have
812 an IO-APIC, then the kernel will still run with no slowdown at all.
814 config X86_LOCAL_APIC
816 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
820 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
822 config X86_VISWS_APIC
824 depends on X86_32 && X86_VISWS
826 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
827 bool "Reroute for broken boot IRQs"
828 depends on X86_IO_APIC
830 This option enables a workaround that fixes a source of
831 spurious interrupts. This is recommended when threaded
832 interrupt handling is used on systems where the generation of
833 superfluous "boot interrupts" cannot be disabled.
835 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
836 entry in the chipset's IO-APIC is masked (as, e.g. the RT
837 kernel does during interrupt handling). On chipsets where this
838 boot IRQ generation cannot be disabled, this workaround keeps
839 the original IRQ line masked so that only the equivalent "boot
840 IRQ" is delivered to the CPUs. The workaround also tells the
841 kernel to set up the IRQ handler on the boot IRQ line. In this
842 way only one interrupt is delivered to the kernel. Otherwise
843 the spurious second interrupt may cause the kernel to bring
844 down (vital) interrupt lines.
846 Only affects "broken" chipsets. Interrupt sharing may be
847 increased on these systems.
850 bool "Machine Check / overheating reporting"
852 Machine Check support allows the processor to notify the
853 kernel if it detects a problem (e.g. overheating, data corruption).
854 The action the kernel takes depends on the severity of the problem,
855 ranging from warning messages to halting the machine.
859 prompt "Intel MCE features"
860 depends on X86_MCE && X86_LOCAL_APIC
862 Additional support for intel specific MCE features such as
867 prompt "AMD MCE features"
868 depends on X86_MCE && X86_LOCAL_APIC
870 Additional support for AMD specific MCE features such as
871 the DRAM Error Threshold.
873 config X86_ANCIENT_MCE
874 bool "Support for old Pentium 5 / WinChip machine checks"
875 depends on X86_32 && X86_MCE
877 Include support for machine check handling on old Pentium 5 or WinChip
878 systems. These typically need to be enabled explicitely on the command
881 config X86_MCE_THRESHOLD
882 depends on X86_MCE_AMD || X86_MCE_INTEL
885 config X86_MCE_INJECT
887 tristate "Machine check injector support"
889 Provide support for injecting machine checks for testing purposes.
890 If you don't know what a machine check is and you don't do kernel
891 QA it is safe to say n.
893 config X86_THERMAL_VECTOR
895 depends on X86_MCE_INTEL
898 bool "Enable VM86 support" if EXPERT
902 This option is required by programs like DOSEMU to run 16-bit legacy
903 code on X86 processors. It also may be needed by software like
904 XFree86 to initialize some video cards via BIOS. Disabling this
905 option saves about 6k.
908 tristate "Toshiba Laptop support"
911 This adds a driver to safely access the System Management Mode of
912 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
913 not work on models with a Phoenix BIOS. The System Management Mode
914 is used to set the BIOS and power saving options on Toshiba portables.
916 For information on utilities to make use of this driver see the
917 Toshiba Linux utilities web site at:
918 <http://www.buzzard.org.uk/toshiba/>.
920 Say Y if you intend to run this kernel on a Toshiba portable.
924 tristate "Dell laptop support"
926 This adds a driver to safely access the System Management Mode
927 of the CPU on the Dell Inspiron 8000. The System Management Mode
928 is used to read cpu temperature and cooling fan status and to
929 control the fans on the I8K portables.
931 This driver has been tested only on the Inspiron 8000 but it may
932 also work with other Dell laptops. You can force loading on other
933 models by passing the parameter `force=1' to the module. Use at
936 For information on utilities to make use of this driver see the
937 I8K Linux utilities web site at:
938 <http://people.debian.org/~dz/i8k/>
940 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
943 config X86_REBOOTFIXUPS
944 bool "Enable X86 board specific fixups for reboot"
947 This enables chipset and/or board specific fixups to be done
948 in order to get reboot to work correctly. This is only needed on
949 some combinations of hardware and BIOS. The symptom, for which
950 this config is intended, is when reboot ends with a stalled/hung
953 Currently, the only fixup is for the Geode machines using
954 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
956 Say Y if you want to enable the fixup. Currently, it's safe to
957 enable this option even if you don't need it.
961 tristate "/dev/cpu/microcode - microcode support"
964 If you say Y here, you will be able to update the microcode on
965 certain Intel and AMD processors. The Intel support is for the
966 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
967 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
968 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
969 You will obviously need the actual microcode binary data itself
970 which is not shipped with the Linux kernel.
972 This option selects the general module only, you need to select
973 at least one vendor specific module as well.
975 To compile this driver as a module, choose M here: the
976 module will be called microcode.
978 config MICROCODE_INTEL
979 bool "Intel microcode patch loading support"
984 This options enables microcode patch loading support for Intel
987 For latest news and information on obtaining all the required
988 Intel ingredients for this driver, check:
989 <http://www.urbanmyth.org/microcode/>.
992 bool "AMD microcode patch loading support"
996 If you select this option, microcode patch loading support for AMD
997 processors will be enabled.
999 config MICROCODE_OLD_INTERFACE
1001 depends on MICROCODE
1004 tristate "/dev/cpu/*/msr - Model-specific register support"
1006 This device gives privileged processes access to the x86
1007 Model-Specific Registers (MSRs). It is a character device with
1008 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1009 MSR accesses are directed to a specific CPU on multi-processor
1013 tristate "/dev/cpu/*/cpuid - CPU information support"
1015 This device gives processes access to the x86 CPUID instruction to
1016 be executed on a specific processor. It is a character device
1017 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1021 prompt "High Memory Support"
1022 default HIGHMEM64G if X86_NUMAQ
1028 depends on !X86_NUMAQ
1030 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1031 However, the address space of 32-bit x86 processors is only 4
1032 Gigabytes large. That means that, if you have a large amount of
1033 physical memory, not all of it can be "permanently mapped" by the
1034 kernel. The physical memory that's not permanently mapped is called
1037 If you are compiling a kernel which will never run on a machine with
1038 more than 1 Gigabyte total physical RAM, answer "off" here (default
1039 choice and suitable for most users). This will result in a "3GB/1GB"
1040 split: 3GB are mapped so that each process sees a 3GB virtual memory
1041 space and the remaining part of the 4GB virtual memory space is used
1042 by the kernel to permanently map as much physical memory as
1045 If the machine has between 1 and 4 Gigabytes physical RAM, then
1048 If more than 4 Gigabytes is used then answer "64GB" here. This
1049 selection turns Intel PAE (Physical Address Extension) mode on.
1050 PAE implements 3-level paging on IA32 processors. PAE is fully
1051 supported by Linux, PAE mode is implemented on all recent Intel
1052 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1053 then the kernel will not boot on CPUs that don't support PAE!
1055 The actual amount of total physical memory will either be
1056 auto detected or can be forced by using a kernel command line option
1057 such as "mem=256M". (Try "man bootparam" or see the documentation of
1058 your boot loader (lilo or loadlin) about how to pass options to the
1059 kernel at boot time.)
1061 If unsure, say "off".
1065 depends on !X86_NUMAQ
1067 Select this if you have a 32-bit processor and between 1 and 4
1068 gigabytes of physical RAM.
1072 depends on !M386 && !M486
1075 Select this if you have a 32-bit processor and more than 4
1076 gigabytes of physical RAM.
1081 depends on EXPERIMENTAL
1082 prompt "Memory split" if EXPERT
1086 Select the desired split between kernel and user memory.
1088 If the address range available to the kernel is less than the
1089 physical memory installed, the remaining memory will be available
1090 as "high memory". Accessing high memory is a little more costly
1091 than low memory, as it needs to be mapped into the kernel first.
1092 Note that increasing the kernel address space limits the range
1093 available to user programs, making the address space there
1094 tighter. Selecting anything other than the default 3G/1G split
1095 will also likely make your kernel incompatible with binary-only
1098 If you are not absolutely sure what you are doing, leave this
1102 bool "3G/1G user/kernel split"
1103 config VMSPLIT_3G_OPT
1105 bool "3G/1G user/kernel split (for full 1G low memory)"
1107 bool "2G/2G user/kernel split"
1108 config VMSPLIT_2G_OPT
1110 bool "2G/2G user/kernel split (for full 2G low memory)"
1112 bool "1G/3G user/kernel split"
1117 default 0xB0000000 if VMSPLIT_3G_OPT
1118 default 0x80000000 if VMSPLIT_2G
1119 default 0x78000000 if VMSPLIT_2G_OPT
1120 default 0x40000000 if VMSPLIT_1G
1126 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1129 bool "PAE (Physical Address Extension) Support"
1130 depends on X86_32 && !HIGHMEM4G
1132 PAE is required for NX support, and furthermore enables
1133 larger swapspace support for non-overcommit purposes. It
1134 has the cost of more pagetable lookup overhead, and also
1135 consumes more pagetable space per process.
1137 config ARCH_PHYS_ADDR_T_64BIT
1138 def_bool X86_64 || X86_PAE
1140 config ARCH_DMA_ADDR_T_64BIT
1141 def_bool X86_64 || HIGHMEM64G
1143 config DIRECT_GBPAGES
1144 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1148 Allow the kernel linear mapping to use 1GB pages on CPUs that
1149 support it. This can improve the kernel's performance a tiny bit by
1150 reducing TLB pressure. If in doubt, say "Y".
1152 # Common NUMA Features
1154 bool "Numa Memory Allocation and Scheduler Support"
1156 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1157 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1159 Enable NUMA (Non Uniform Memory Access) support.
1161 The kernel will try to allocate memory used by a CPU on the
1162 local memory controller of the CPU and add some more
1163 NUMA awareness to the kernel.
1165 For 64-bit this is recommended if the system is Intel Core i7
1166 (or later), AMD Opteron, or EM64T NUMA.
1168 For 32-bit this is only needed on (rare) 32-bit-only platforms
1169 that support NUMA topologies, such as NUMAQ / Summit, or if you
1170 boot a 32-bit kernel on a 64-bit NUMA platform.
1172 Otherwise, you should say N.
1174 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1175 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1179 prompt "Old style AMD Opteron NUMA detection"
1180 depends on X86_64 && NUMA && PCI
1182 Enable AMD NUMA node topology detection. You should say Y here if
1183 you have a multi processor AMD system. This uses an old method to
1184 read the NUMA configuration directly from the builtin Northbridge
1185 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1186 which also takes priority if both are compiled in.
1188 config X86_64_ACPI_NUMA
1190 prompt "ACPI NUMA detection"
1191 depends on X86_64 && NUMA && ACPI && PCI
1194 Enable ACPI SRAT based node topology detection.
1196 # Some NUMA nodes have memory ranges that span
1197 # other nodes. Even though a pfn is valid and
1198 # between a node's start and end pfns, it may not
1199 # reside on that node. See memmap_init_zone()
1201 config NODES_SPAN_OTHER_NODES
1203 depends on X86_64_ACPI_NUMA
1206 bool "NUMA emulation"
1207 depends on X86_64 && NUMA
1209 Enable NUMA emulation. A flat machine will be split
1210 into virtual nodes when booted with "numa=fake=N", where N is the
1211 number of nodes. This is only useful for debugging.
1214 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1216 default "10" if MAXSMP
1217 default "6" if X86_64
1218 default "4" if X86_NUMAQ
1220 depends on NEED_MULTIPLE_NODES
1222 Specify the maximum number of NUMA Nodes available on the target
1223 system. Increases memory reserved to accommodate various tables.
1225 config HAVE_ARCH_BOOTMEM
1227 depends on X86_32 && NUMA
1229 config ARCH_HAVE_MEMORY_PRESENT
1231 depends on X86_32 && DISCONTIGMEM
1233 config NEED_NODE_MEMMAP_SIZE
1235 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1237 config HAVE_ARCH_ALLOC_REMAP
1239 depends on X86_32 && NUMA
1241 config ARCH_FLATMEM_ENABLE
1243 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1245 config ARCH_DISCONTIGMEM_ENABLE
1247 depends on NUMA && X86_32
1249 config ARCH_DISCONTIGMEM_DEFAULT
1251 depends on NUMA && X86_32
1253 config ARCH_PROC_KCORE_TEXT
1255 depends on X86_64 && PROC_KCORE
1257 config ARCH_SPARSEMEM_DEFAULT
1261 config ARCH_SPARSEMEM_ENABLE
1263 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1264 select SPARSEMEM_STATIC if X86_32
1265 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1267 config ARCH_SELECT_MEMORY_MODEL
1269 depends on ARCH_SPARSEMEM_ENABLE
1271 config ARCH_MEMORY_PROBE
1273 depends on MEMORY_HOTPLUG
1275 config ILLEGAL_POINTER_VALUE
1278 default 0xdead000000000000 if X86_64
1283 bool "Allocate 3rd-level pagetables from highmem"
1286 The VM uses one page table entry for each page of physical memory.
1287 For systems with a lot of RAM, this can be wasteful of precious
1288 low memory. Setting this option will put user-space page table
1289 entries in high memory.
1291 config X86_CHECK_BIOS_CORRUPTION
1292 bool "Check for low memory corruption"
1294 Periodically check for memory corruption in low memory, which
1295 is suspected to be caused by BIOS. Even when enabled in the
1296 configuration, it is disabled at runtime. Enable it by
1297 setting "memory_corruption_check=1" on the kernel command
1298 line. By default it scans the low 64k of memory every 60
1299 seconds; see the memory_corruption_check_size and
1300 memory_corruption_check_period parameters in
1301 Documentation/kernel-parameters.txt to adjust this.
1303 When enabled with the default parameters, this option has
1304 almost no overhead, as it reserves a relatively small amount
1305 of memory and scans it infrequently. It both detects corruption
1306 and prevents it from affecting the running system.
1308 It is, however, intended as a diagnostic tool; if repeatable
1309 BIOS-originated corruption always affects the same memory,
1310 you can use memmap= to prevent the kernel from using that
1313 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1314 bool "Set the default setting of memory_corruption_check"
1315 depends on X86_CHECK_BIOS_CORRUPTION
1318 Set whether the default state of memory_corruption_check is
1321 config X86_RESERVE_LOW
1322 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1326 Specify the amount of low memory to reserve for the BIOS.
1328 The first page contains BIOS data structures that the kernel
1329 must not use, so that page must always be reserved.
1331 By default we reserve the first 64K of physical RAM, as a
1332 number of BIOSes are known to corrupt that memory range
1333 during events such as suspend/resume or monitor cable
1334 insertion, so it must not be used by the kernel.
1336 You can set this to 4 if you are absolutely sure that you
1337 trust the BIOS to get all its memory reservations and usages
1338 right. If you know your BIOS have problems beyond the
1339 default 64K area, you can set this to 640 to avoid using the
1340 entire low memory range.
1342 If you have doubts about the BIOS (e.g. suspend/resume does
1343 not work or there's kernel crashes after certain hardware
1344 hotplug events) then you might want to enable
1345 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1346 typical corruption patterns.
1348 Leave this to the default value of 64 if you are unsure.
1350 config MATH_EMULATION
1352 prompt "Math emulation" if X86_32
1354 Linux can emulate a math coprocessor (used for floating point
1355 operations) if you don't have one. 486DX and Pentium processors have
1356 a math coprocessor built in, 486SX and 386 do not, unless you added
1357 a 487DX or 387, respectively. (The messages during boot time can
1358 give you some hints here ["man dmesg"].) Everyone needs either a
1359 coprocessor or this emulation.
1361 If you don't have a math coprocessor, you need to say Y here; if you
1362 say Y here even though you have a coprocessor, the coprocessor will
1363 be used nevertheless. (This behavior can be changed with the kernel
1364 command line option "no387", which comes handy if your coprocessor
1365 is broken. Try "man bootparam" or see the documentation of your boot
1366 loader (lilo or loadlin) about how to pass options to the kernel at
1367 boot time.) This means that it is a good idea to say Y here if you
1368 intend to use this kernel on different machines.
1370 More information about the internals of the Linux math coprocessor
1371 emulation can be found in <file:arch/x86/math-emu/README>.
1373 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1374 kernel, it won't hurt.
1378 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1380 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1381 the Memory Type Range Registers (MTRRs) may be used to control
1382 processor access to memory ranges. This is most useful if you have
1383 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1384 allows bus write transfers to be combined into a larger transfer
1385 before bursting over the PCI/AGP bus. This can increase performance
1386 of image write operations 2.5 times or more. Saying Y here creates a
1387 /proc/mtrr file which may be used to manipulate your processor's
1388 MTRRs. Typically the X server should use this.
1390 This code has a reasonably generic interface so that similar
1391 control registers on other processors can be easily supported
1394 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1395 Registers (ARRs) which provide a similar functionality to MTRRs. For
1396 these, the ARRs are used to emulate the MTRRs.
1397 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1398 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1399 write-combining. All of these processors are supported by this code
1400 and it makes sense to say Y here if you have one of them.
1402 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1403 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1404 can lead to all sorts of problems, so it's good to say Y here.
1406 You can safely say Y even if your machine doesn't have MTRRs, you'll
1407 just add about 9 KB to your kernel.
1409 See <file:Documentation/x86/mtrr.txt> for more information.
1411 config MTRR_SANITIZER
1413 prompt "MTRR cleanup support"
1416 Convert MTRR layout from continuous to discrete, so X drivers can
1417 add writeback entries.
1419 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1420 The largest mtrr entry size for a continuous block can be set with
1425 config MTRR_SANITIZER_ENABLE_DEFAULT
1426 int "MTRR cleanup enable value (0-1)"
1429 depends on MTRR_SANITIZER
1431 Enable mtrr cleanup default value
1433 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1434 int "MTRR cleanup spare reg num (0-7)"
1437 depends on MTRR_SANITIZER
1439 mtrr cleanup spare entries default, it can be changed via
1440 mtrr_spare_reg_nr=N on the kernel command line.
1444 prompt "x86 PAT support" if EXPERT
1447 Use PAT attributes to setup page level cache control.
1449 PATs are the modern equivalents of MTRRs and are much more
1450 flexible than MTRRs.
1452 Say N here if you see bootup problems (boot crash, boot hang,
1453 spontaneous reboots) or a non-working video driver.
1457 config ARCH_USES_PG_UNCACHED
1462 bool "EFI runtime service support"
1465 This enables the kernel to use EFI runtime services that are
1466 available (such as the EFI variable services).
1468 This option is only useful on systems that have EFI firmware.
1469 In addition, you should use the latest ELILO loader available
1470 at <http://elilo.sourceforge.net> in order to take advantage
1471 of EFI runtime services. However, even with this option, the
1472 resultant kernel should continue to boot on existing non-EFI
1477 prompt "Enable seccomp to safely compute untrusted bytecode"
1479 This kernel feature is useful for number crunching applications
1480 that may need to compute untrusted bytecode during their
1481 execution. By using pipes or other transports made available to
1482 the process as file descriptors supporting the read/write
1483 syscalls, it's possible to isolate those applications in
1484 their own address space using seccomp. Once seccomp is
1485 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1486 and the task is only allowed to execute a few safe syscalls
1487 defined by each seccomp mode.
1489 If unsure, say Y. Only embedded should say N here.
1491 config CC_STACKPROTECTOR
1492 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1494 This option turns on the -fstack-protector GCC feature. This
1495 feature puts, at the beginning of functions, a canary value on
1496 the stack just before the return address, and validates
1497 the value just before actually returning. Stack based buffer
1498 overflows (that need to overwrite this return address) now also
1499 overwrite the canary, which gets detected and the attack is then
1500 neutralized via a kernel panic.
1502 This feature requires gcc version 4.2 or above, or a distribution
1503 gcc with the feature backported. Older versions are automatically
1504 detected and for those versions, this configuration option is
1505 ignored. (and a warning is printed during bootup)
1507 source kernel/Kconfig.hz
1510 bool "kexec system call"
1512 kexec is a system call that implements the ability to shutdown your
1513 current kernel, and to start another kernel. It is like a reboot
1514 but it is independent of the system firmware. And like a reboot
1515 you can start any kernel with it, not just Linux.
1517 The name comes from the similarity to the exec system call.
1519 It is an ongoing process to be certain the hardware in a machine
1520 is properly shutdown, so do not be surprised if this code does not
1521 initially work for you. It may help to enable device hotplugging
1522 support. As of this writing the exact hardware interface is
1523 strongly in flux, so no good recommendation can be made.
1526 bool "kernel crash dumps"
1527 depends on X86_64 || (X86_32 && HIGHMEM)
1529 Generate crash dump after being started by kexec.
1530 This should be normally only set in special crash dump kernels
1531 which are loaded in the main kernel with kexec-tools into
1532 a specially reserved region and then later executed after
1533 a crash by kdump/kexec. The crash dump kernel must be compiled
1534 to a memory address not used by the main kernel or BIOS using
1535 PHYSICAL_START, or it must be built as a relocatable image
1536 (CONFIG_RELOCATABLE=y).
1537 For more details see Documentation/kdump/kdump.txt
1540 bool "kexec jump (EXPERIMENTAL)"
1541 depends on EXPERIMENTAL
1542 depends on KEXEC && HIBERNATION
1544 Jump between original kernel and kexeced kernel and invoke
1545 code in physical address mode via KEXEC
1547 config PHYSICAL_START
1548 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1551 This gives the physical address where the kernel is loaded.
1553 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1554 bzImage will decompress itself to above physical address and
1555 run from there. Otherwise, bzImage will run from the address where
1556 it has been loaded by the boot loader and will ignore above physical
1559 In normal kdump cases one does not have to set/change this option
1560 as now bzImage can be compiled as a completely relocatable image
1561 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1562 address. This option is mainly useful for the folks who don't want
1563 to use a bzImage for capturing the crash dump and want to use a
1564 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1565 to be specifically compiled to run from a specific memory area
1566 (normally a reserved region) and this option comes handy.
1568 So if you are using bzImage for capturing the crash dump,
1569 leave the value here unchanged to 0x1000000 and set
1570 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1571 for capturing the crash dump change this value to start of
1572 the reserved region. In other words, it can be set based on
1573 the "X" value as specified in the "crashkernel=YM@XM"
1574 command line boot parameter passed to the panic-ed
1575 kernel. Please take a look at Documentation/kdump/kdump.txt
1576 for more details about crash dumps.
1578 Usage of bzImage for capturing the crash dump is recommended as
1579 one does not have to build two kernels. Same kernel can be used
1580 as production kernel and capture kernel. Above option should have
1581 gone away after relocatable bzImage support is introduced. But it
1582 is present because there are users out there who continue to use
1583 vmlinux for dump capture. This option should go away down the
1586 Don't change this unless you know what you are doing.
1589 bool "Build a relocatable kernel"
1592 This builds a kernel image that retains relocation information
1593 so it can be loaded someplace besides the default 1MB.
1594 The relocations tend to make the kernel binary about 10% larger,
1595 but are discarded at runtime.
1597 One use is for the kexec on panic case where the recovery kernel
1598 must live at a different physical address than the primary
1601 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1602 it has been loaded at and the compile time physical address
1603 (CONFIG_PHYSICAL_START) is ignored.
1605 # Relocation on x86-32 needs some additional build support
1606 config X86_NEED_RELOCS
1608 depends on X86_32 && RELOCATABLE
1610 config PHYSICAL_ALIGN
1611 hex "Alignment value to which kernel should be aligned" if X86_32
1613 range 0x2000 0x1000000
1615 This value puts the alignment restrictions on physical address
1616 where kernel is loaded and run from. Kernel is compiled for an
1617 address which meets above alignment restriction.
1619 If bootloader loads the kernel at a non-aligned address and
1620 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1621 address aligned to above value and run from there.
1623 If bootloader loads the kernel at a non-aligned address and
1624 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1625 load address and decompress itself to the address it has been
1626 compiled for and run from there. The address for which kernel is
1627 compiled already meets above alignment restrictions. Hence the
1628 end result is that kernel runs from a physical address meeting
1629 above alignment restrictions.
1631 Don't change this unless you know what you are doing.
1634 bool "Support for hot-pluggable CPUs"
1635 depends on SMP && HOTPLUG
1637 Say Y here to allow turning CPUs off and on. CPUs can be
1638 controlled through /sys/devices/system/cpu.
1639 ( Note: power management support will enable this option
1640 automatically on SMP systems. )
1641 Say N if you want to disable CPU hotplug.
1645 prompt "Compat VDSO support"
1646 depends on X86_32 || IA32_EMULATION
1648 Map the 32-bit VDSO to the predictable old-style address too.
1650 Say N here if you are running a sufficiently recent glibc
1651 version (2.3.3 or later), to remove the high-mapped
1652 VDSO mapping and to exclusively use the randomized VDSO.
1657 bool "Built-in kernel command line"
1659 Allow for specifying boot arguments to the kernel at
1660 build time. On some systems (e.g. embedded ones), it is
1661 necessary or convenient to provide some or all of the
1662 kernel boot arguments with the kernel itself (that is,
1663 to not rely on the boot loader to provide them.)
1665 To compile command line arguments into the kernel,
1666 set this option to 'Y', then fill in the
1667 the boot arguments in CONFIG_CMDLINE.
1669 Systems with fully functional boot loaders (i.e. non-embedded)
1670 should leave this option set to 'N'.
1673 string "Built-in kernel command string"
1674 depends on CMDLINE_BOOL
1677 Enter arguments here that should be compiled into the kernel
1678 image and used at boot time. If the boot loader provides a
1679 command line at boot time, it is appended to this string to
1680 form the full kernel command line, when the system boots.
1682 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1683 change this behavior.
1685 In most cases, the command line (whether built-in or provided
1686 by the boot loader) should specify the device for the root
1689 config CMDLINE_OVERRIDE
1690 bool "Built-in command line overrides boot loader arguments"
1691 depends on CMDLINE_BOOL
1693 Set this option to 'Y' to have the kernel ignore the boot loader
1694 command line, and use ONLY the built-in command line.
1696 This is used to work around broken boot loaders. This should
1697 be set to 'N' under normal conditions.
1701 config ARCH_ENABLE_MEMORY_HOTPLUG
1703 depends on X86_64 || (X86_32 && HIGHMEM)
1705 config ARCH_ENABLE_MEMORY_HOTREMOVE
1707 depends on MEMORY_HOTPLUG
1709 config HAVE_ARCH_EARLY_PFN_TO_NID
1713 config USE_PERCPU_NUMA_NODE_ID
1717 menu "Power management and ACPI options"
1719 config ARCH_HIBERNATION_HEADER
1721 depends on X86_64 && HIBERNATION
1723 source "kernel/power/Kconfig"
1725 source "drivers/acpi/Kconfig"
1727 source "drivers/sfi/Kconfig"
1731 depends on APM || APM_MODULE
1734 tristate "APM (Advanced Power Management) BIOS support"
1735 depends on X86_32 && PM_SLEEP
1737 APM is a BIOS specification for saving power using several different
1738 techniques. This is mostly useful for battery powered laptops with
1739 APM compliant BIOSes. If you say Y here, the system time will be
1740 reset after a RESUME operation, the /proc/apm device will provide
1741 battery status information, and user-space programs will receive
1742 notification of APM "events" (e.g. battery status change).
1744 If you select "Y" here, you can disable actual use of the APM
1745 BIOS by passing the "apm=off" option to the kernel at boot time.
1747 Note that the APM support is almost completely disabled for
1748 machines with more than one CPU.
1750 In order to use APM, you will need supporting software. For location
1751 and more information, read <file:Documentation/power/pm.txt> and the
1752 Battery Powered Linux mini-HOWTO, available from
1753 <http://www.tldp.org/docs.html#howto>.
1755 This driver does not spin down disk drives (see the hdparm(8)
1756 manpage ("man 8 hdparm") for that), and it doesn't turn off
1757 VESA-compliant "green" monitors.
1759 This driver does not support the TI 4000M TravelMate and the ACER
1760 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1761 desktop machines also don't have compliant BIOSes, and this driver
1762 may cause those machines to panic during the boot phase.
1764 Generally, if you don't have a battery in your machine, there isn't
1765 much point in using this driver and you should say N. If you get
1766 random kernel OOPSes or reboots that don't seem to be related to
1767 anything, try disabling/enabling this option (or disabling/enabling
1770 Some other things you should try when experiencing seemingly random,
1773 1) make sure that you have enough swap space and that it is
1775 2) pass the "no-hlt" option to the kernel
1776 3) switch on floating point emulation in the kernel and pass
1777 the "no387" option to the kernel
1778 4) pass the "floppy=nodma" option to the kernel
1779 5) pass the "mem=4M" option to the kernel (thereby disabling
1780 all but the first 4 MB of RAM)
1781 6) make sure that the CPU is not over clocked.
1782 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1783 8) disable the cache from your BIOS settings
1784 9) install a fan for the video card or exchange video RAM
1785 10) install a better fan for the CPU
1786 11) exchange RAM chips
1787 12) exchange the motherboard.
1789 To compile this driver as a module, choose M here: the
1790 module will be called apm.
1794 config APM_IGNORE_USER_SUSPEND
1795 bool "Ignore USER SUSPEND"
1797 This option will ignore USER SUSPEND requests. On machines with a
1798 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1799 series notebooks, it is necessary to say Y because of a BIOS bug.
1801 config APM_DO_ENABLE
1802 bool "Enable PM at boot time"
1804 Enable APM features at boot time. From page 36 of the APM BIOS
1805 specification: "When disabled, the APM BIOS does not automatically
1806 power manage devices, enter the Standby State, enter the Suspend
1807 State, or take power saving steps in response to CPU Idle calls."
1808 This driver will make CPU Idle calls when Linux is idle (unless this
1809 feature is turned off -- see "Do CPU IDLE calls", below). This
1810 should always save battery power, but more complicated APM features
1811 will be dependent on your BIOS implementation. You may need to turn
1812 this option off if your computer hangs at boot time when using APM
1813 support, or if it beeps continuously instead of suspending. Turn
1814 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1815 T400CDT. This is off by default since most machines do fine without
1819 bool "Make CPU Idle calls when idle"
1821 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1822 On some machines, this can activate improved power savings, such as
1823 a slowed CPU clock rate, when the machine is idle. These idle calls
1824 are made after the idle loop has run for some length of time (e.g.,
1825 333 mS). On some machines, this will cause a hang at boot time or
1826 whenever the CPU becomes idle. (On machines with more than one CPU,
1827 this option does nothing.)
1829 config APM_DISPLAY_BLANK
1830 bool "Enable console blanking using APM"
1832 Enable console blanking using the APM. Some laptops can use this to
1833 turn off the LCD backlight when the screen blanker of the Linux
1834 virtual console blanks the screen. Note that this is only used by
1835 the virtual console screen blanker, and won't turn off the backlight
1836 when using the X Window system. This also doesn't have anything to
1837 do with your VESA-compliant power-saving monitor. Further, this
1838 option doesn't work for all laptops -- it might not turn off your
1839 backlight at all, or it might print a lot of errors to the console,
1840 especially if you are using gpm.
1842 config APM_ALLOW_INTS
1843 bool "Allow interrupts during APM BIOS calls"
1845 Normally we disable external interrupts while we are making calls to
1846 the APM BIOS as a measure to lessen the effects of a badly behaving
1847 BIOS implementation. The BIOS should reenable interrupts if it
1848 needs to. Unfortunately, some BIOSes do not -- especially those in
1849 many of the newer IBM Thinkpads. If you experience hangs when you
1850 suspend, try setting this to Y. Otherwise, say N.
1854 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1856 source "drivers/cpuidle/Kconfig"
1858 source "drivers/idle/Kconfig"
1863 menu "Bus options (PCI etc.)"
1868 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1870 Find out whether you have a PCI motherboard. PCI is the name of a
1871 bus system, i.e. the way the CPU talks to the other stuff inside
1872 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1873 VESA. If you have PCI, say Y, otherwise N.
1876 prompt "PCI access mode"
1877 depends on X86_32 && PCI
1880 On PCI systems, the BIOS can be used to detect the PCI devices and
1881 determine their configuration. However, some old PCI motherboards
1882 have BIOS bugs and may crash if this is done. Also, some embedded
1883 PCI-based systems don't have any BIOS at all. Linux can also try to
1884 detect the PCI hardware directly without using the BIOS.
1886 With this option, you can specify how Linux should detect the
1887 PCI devices. If you choose "BIOS", the BIOS will be used,
1888 if you choose "Direct", the BIOS won't be used, and if you
1889 choose "MMConfig", then PCI Express MMCONFIG will be used.
1890 If you choose "Any", the kernel will try MMCONFIG, then the
1891 direct access method and falls back to the BIOS if that doesn't
1892 work. If unsure, go with the default, which is "Any".
1897 config PCI_GOMMCONFIG
1914 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1916 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1919 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1923 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1927 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1931 depends on PCI && XEN
1939 bool "Support mmconfig PCI config space access"
1940 depends on X86_64 && PCI && ACPI
1942 config PCI_CNB20LE_QUIRK
1943 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1945 depends on PCI && EXPERIMENTAL
1947 Read the PCI windows out of the CNB20LE host bridge. This allows
1948 PCI hotplug to work on systems with the CNB20LE chipset which do
1951 There's no public spec for this chipset, and this functionality
1952 is known to be incomplete.
1954 You should say N unless you know you need this.
1957 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1958 depends on PCI_MSI && ACPI && EXPERIMENTAL
1960 DMA remapping (DMAR) devices support enables independent address
1961 translations for Direct Memory Access (DMA) from devices.
1962 These DMA remapping devices are reported via ACPI tables
1963 and include PCI device scope covered by these DMA
1966 config DMAR_DEFAULT_ON
1968 prompt "Enable DMA Remapping Devices by default"
1971 Selecting this option will enable a DMAR device at boot time if
1972 one is found. If this option is not selected, DMAR support can
1973 be enabled by passing intel_iommu=on to the kernel. It is
1974 recommended you say N here while the DMAR code remains
1977 config DMAR_BROKEN_GFX_WA
1978 bool "Workaround broken graphics drivers (going away soon)"
1979 depends on DMAR && BROKEN
1981 Current Graphics drivers tend to use physical address
1982 for DMA and avoid using DMA APIs. Setting this config
1983 option permits the IOMMU driver to set a unity map for
1984 all the OS-visible memory. Hence the driver can continue
1985 to use physical addresses for DMA, at least until this
1986 option is removed in the 2.6.32 kernel.
1988 config DMAR_FLOPPY_WA
1992 Floppy disk drivers are known to bypass DMA API calls
1993 thereby failing to work when IOMMU is enabled. This
1994 workaround will setup a 1:1 mapping for the first
1995 16MiB to make floppy (an ISA device) work.
1998 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1999 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
2001 Supports Interrupt remapping for IO-APIC and MSI devices.
2002 To use x2apic mode in the CPU's which support x2APIC enhancements or
2003 to support platforms with CPU's having > 8 bit APIC ID, say Y.
2005 source "drivers/pci/pcie/Kconfig"
2007 source "drivers/pci/Kconfig"
2009 # x86_64 have no ISA slots, but do have ISA-style DMA.
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"
2045 MicroChannel Architecture is found in some IBM PS/2 machines and
2046 laptops. It is a bus system similar to PCI or ISA. See
2047 <file:Documentation/mca.txt> (and especially the web page given
2048 there) before attempting to build an MCA bus kernel.
2050 source "drivers/mca/Kconfig"
2053 tristate "NatSemi SCx200 support"
2055 This provides basic support for National Semiconductor's
2056 (now AMD's) Geode processors. The driver probes for the
2057 PCI-IDs of several on-chip devices, so its a good dependency
2058 for other scx200_* drivers.
2060 If compiled as a module, the driver is named scx200.
2062 config SCx200HR_TIMER
2063 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2067 This driver provides a clocksource built upon the on-chip
2068 27MHz high-resolution timer. Its also a workaround for
2069 NSC Geode SC-1100's buggy TSC, which loses time when the
2070 processor goes idle (as is done by the scheduler). The
2071 other workaround is idle=poll boot option.
2074 bool "One Laptop Per Child support"
2078 select OF_PROMTREE if PROC_DEVICETREE
2080 Add support for detecting the unique features of the OLPC
2084 tristate "OLPC XO-1 support"
2085 depends on OLPC && MFD_CS5535
2087 Add support for non-essential features of the OLPC XO-1 laptop.
2093 depends on CPU_SUP_AMD && PCI
2095 source "drivers/pcmcia/Kconfig"
2097 source "drivers/pci/hotplug/Kconfig"
2102 menu "Executable file formats / Emulations"
2104 source "fs/Kconfig.binfmt"
2106 config IA32_EMULATION
2107 bool "IA32 Emulation"
2109 select COMPAT_BINFMT_ELF
2111 Include code to run 32-bit programs under a 64-bit kernel. You should
2112 likely turn this on, unless you're 100% sure that you don't have any
2113 32-bit programs left.
2116 tristate "IA32 a.out support"
2117 depends on IA32_EMULATION
2119 Support old a.out binaries in the 32bit emulation.
2123 depends on IA32_EMULATION
2125 config COMPAT_FOR_U64_ALIGNMENT
2129 config SYSVIPC_COMPAT
2131 depends on COMPAT && SYSVIPC
2136 config HAVE_ATOMIC_IOMAP
2140 config HAVE_TEXT_POKE_SMP
2142 select STOP_MACHINE if SMP
2144 source "net/Kconfig"
2146 source "drivers/Kconfig"
2148 source "drivers/firmware/Kconfig"
2152 source "arch/x86/Kconfig.debug"
2154 source "security/Kconfig"
2156 source "crypto/Kconfig"
2158 source "arch/x86/kvm/Kconfig"
2160 source "lib/Kconfig"