3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select X86_DEV_DMA_OPS
23 select HAVE_AOUT if X86_32
24 select HAVE_UNSTABLE_SCHED_CLOCK
27 select HAVE_PCSPKR_PLATFORM
28 select HAVE_PERF_EVENTS
30 select HAVE_IOREMAP_PROT
33 select HAVE_MEMBLOCK_NODE_MAP
34 select ARCH_DISCARD_MEMBLOCK
35 select ARCH_WANT_OPTIONAL_GPIOLIB
36 select ARCH_WANT_FRAME_POINTERS
38 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
39 select HAVE_KRETPROBES
41 select HAVE_FTRACE_MCOUNT_RECORD
42 select HAVE_FENTRY if X86_64
43 select HAVE_C_RECORDMCOUNT
44 select HAVE_DYNAMIC_FTRACE
45 select HAVE_FUNCTION_TRACER
46 select HAVE_FUNCTION_GRAPH_TRACER
47 select HAVE_FUNCTION_GRAPH_FP_TEST
48 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
49 select HAVE_SYSCALL_TRACEPOINTS
52 select HAVE_ARCH_TRACEHOOK
53 select HAVE_GENERIC_DMA_COHERENT if X86_32
54 select HAVE_EFFICIENT_UNALIGNED_ACCESS
55 select USER_STACKTRACE_SUPPORT
56 select HAVE_REGS_AND_STACK_ACCESS_API
57 select HAVE_DMA_API_DEBUG
58 select HAVE_KERNEL_GZIP
59 select HAVE_KERNEL_BZIP2
60 select HAVE_KERNEL_LZMA
62 select HAVE_KERNEL_LZO
63 select HAVE_HW_BREAKPOINT
64 select HAVE_MIXED_BREAKPOINTS_REGS
66 select HAVE_PERF_EVENTS_NMI
68 select HAVE_PERF_USER_STACK_DUMP
69 select HAVE_DEBUG_KMEMLEAK
71 select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386
72 select HAVE_CMPXCHG_LOCAL if !M386
73 select HAVE_CMPXCHG_DOUBLE
74 select HAVE_ARCH_KMEMCHECK
75 select HAVE_USER_RETURN_NOTIFIER
76 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
77 select HAVE_ARCH_JUMP_LABEL
78 select HAVE_TEXT_POKE_SMP
79 select HAVE_GENERIC_HARDIRQS
80 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
82 select GENERIC_FIND_FIRST_BIT
83 select GENERIC_IRQ_PROBE
84 select GENERIC_PENDING_IRQ if SMP
85 select GENERIC_IRQ_SHOW
86 select GENERIC_CLOCKEVENTS_MIN_ADJUST
87 select IRQ_FORCED_THREADING
88 select USE_GENERIC_SMP_HELPERS if SMP
89 select HAVE_BPF_JIT if X86_64
91 select ARCH_HAVE_NMI_SAFE_CMPXCHG
93 select DCACHE_WORD_ACCESS
94 select GENERIC_SMP_IDLE_THREAD
95 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
96 select HAVE_ARCH_SECCOMP_FILTER
97 select BUILDTIME_EXTABLE_SORT
98 select GENERIC_CMOS_UPDATE
99 select CLOCKSOURCE_WATCHDOG
100 select GENERIC_CLOCKEVENTS
101 select ARCH_CLOCKSOURCE_DATA if X86_64
102 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
103 select GENERIC_TIME_VSYSCALL if X86_64
104 select KTIME_SCALAR if X86_32
105 select GENERIC_STRNCPY_FROM_USER
106 select GENERIC_STRNLEN_USER
107 select HAVE_RCU_USER_QS if X86_64
108 select HAVE_IRQ_TIME_ACCOUNTING
110 config INSTRUCTION_DECODER
112 depends on KPROBES || PERF_EVENTS || UPROBES
116 default "elf32-i386" if X86_32
117 default "elf64-x86-64" if X86_64
119 config ARCH_DEFCONFIG
121 default "arch/x86/configs/i386_defconfig" if X86_32
122 default "arch/x86/configs/x86_64_defconfig" if X86_64
124 config LOCKDEP_SUPPORT
127 config STACKTRACE_SUPPORT
130 config HAVE_LATENCYTOP_SUPPORT
139 config NEED_DMA_MAP_STATE
141 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
143 config NEED_SG_DMA_LENGTH
146 config GENERIC_ISA_DMA
148 depends on ISA_DMA_API
153 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
155 config GENERIC_BUG_RELATIVE_POINTERS
158 config GENERIC_HWEIGHT
164 config ARCH_MAY_HAVE_PC_FDC
166 depends on ISA_DMA_API
168 config RWSEM_GENERIC_SPINLOCK
172 config RWSEM_XCHGADD_ALGORITHM
176 config GENERIC_CALIBRATE_DELAY
179 config ARCH_HAS_CPU_RELAX
182 config ARCH_HAS_DEFAULT_IDLE
185 config ARCH_HAS_CACHE_LINE_SIZE
188 config ARCH_HAS_CPU_AUTOPROBE
191 config HAVE_SETUP_PER_CPU_AREA
194 config NEED_PER_CPU_EMBED_FIRST_CHUNK
197 config NEED_PER_CPU_PAGE_FIRST_CHUNK
200 config ARCH_HIBERNATION_POSSIBLE
203 config ARCH_SUSPEND_POSSIBLE
214 config ARCH_SUPPORTS_OPTIMIZED_INLINING
217 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
220 config HAVE_INTEL_TXT
222 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
226 depends on X86_32 && SMP
230 depends on X86_64 && SMP
236 config X86_32_LAZY_GS
238 depends on X86_32 && !CC_STACKPROTECTOR
240 config ARCH_HWEIGHT_CFLAGS
242 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
243 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
245 config ARCH_CPU_PROBE_RELEASE
247 depends on HOTPLUG_CPU
249 config ARCH_SUPPORTS_UPROBES
252 source "init/Kconfig"
253 source "kernel/Kconfig.freezer"
255 menu "Processor type and features"
258 bool "DMA memory allocation support" if EXPERT
261 DMA memory allocation support allows devices with less than 32-bit
262 addressing to allocate within the first 16MB of address space.
263 Disable if no such devices will be used.
268 bool "Symmetric multi-processing support"
270 This enables support for systems with more than one CPU. If you have
271 a system with only one CPU, like most personal computers, say N. If
272 you have a system with more than one CPU, say Y.
274 If you say N here, the kernel will run on single and multiprocessor
275 machines, but will use only one CPU of a multiprocessor machine. If
276 you say Y here, the kernel will run on many, but not all,
277 singleprocessor machines. On a singleprocessor machine, the kernel
278 will run faster if you say N here.
280 Note that if you say Y here and choose architecture "586" or
281 "Pentium" under "Processor family", the kernel will not work on 486
282 architectures. Similarly, multiprocessor kernels for the "PPro"
283 architecture may not work on all Pentium based boards.
285 People using multiprocessor machines who say Y here should also say
286 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
287 Management" code will be disabled if you say Y here.
289 See also <file:Documentation/x86/i386/IO-APIC.txt>,
290 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
291 <http://www.tldp.org/docs.html#howto>.
293 If you don't know what to do here, say N.
296 bool "Support x2apic"
297 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
299 This enables x2apic support on CPUs that have this feature.
301 This allows 32-bit apic IDs (so it can support very large systems),
302 and accesses the local apic via MSRs not via mmio.
304 If you don't know what to do here, say N.
307 bool "Enable MPS table" if ACPI
309 depends on X86_LOCAL_APIC
311 For old smp systems that do not have proper acpi support. Newer systems
312 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
315 bool "Support for big SMP systems with more than 8 CPUs"
316 depends on X86_32 && SMP
318 This option is needed for the systems that have more than 8 CPUs
321 config X86_EXTENDED_PLATFORM
322 bool "Support for extended (non-PC) x86 platforms"
325 If you disable this option then the kernel will only support
326 standard PC platforms. (which covers the vast majority of
329 If you enable this option then you'll be able to select support
330 for the following (non-PC) 32 bit x86 platforms:
334 SGI 320/540 (Visual Workstation)
335 STA2X11-based (e.g. Northville)
336 Summit/EXA (IBM x440)
337 Unisys ES7000 IA32 series
338 Moorestown MID devices
340 If you have one of these systems, or if you want to build a
341 generic distribution kernel, say Y here - otherwise say N.
345 config X86_EXTENDED_PLATFORM
346 bool "Support for extended (non-PC) x86 platforms"
349 If you disable this option then the kernel will only support
350 standard PC platforms. (which covers the vast majority of
353 If you enable this option then you'll be able to select support
354 for the following (non-PC) 64 bit x86 platforms:
359 If you have one of these systems, or if you want to build a
360 generic distribution kernel, say Y here - otherwise say N.
362 # This is an alphabetically sorted list of 64 bit extended platforms
363 # Please maintain the alphabetic order if and when there are additions
365 bool "Numascale NumaChip"
367 depends on X86_EXTENDED_PLATFORM
370 depends on X86_X2APIC
372 Adds support for Numascale NumaChip large-SMP systems. Needed to
373 enable more than ~168 cores.
374 If you don't have one of these, you should say N here.
378 select PARAVIRT_GUEST
380 depends on X86_64 && PCI
381 depends on X86_EXTENDED_PLATFORM
384 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
385 supposed to run on these EM64T-based machines. Only choose this option
386 if you have one of these machines.
389 bool "SGI Ultraviolet"
391 depends on X86_EXTENDED_PLATFORM
393 depends on X86_X2APIC
395 This option is needed in order to support SGI Ultraviolet systems.
396 If you don't have one of these, you should say N here.
398 # Following is an alphabetically sorted list of 32 bit extended platforms
399 # Please maintain the alphabetic order if and when there are additions
402 bool "CE4100 TV platform"
404 depends on PCI_GODIRECT
406 depends on X86_EXTENDED_PLATFORM
407 select X86_REBOOTFIXUPS
409 select OF_EARLY_FLATTREE
412 Select for the Intel CE media processor (CE4100) SOC.
413 This option compiles in support for the CE4100 SOC for settop
414 boxes and media devices.
416 config X86_WANT_INTEL_MID
417 bool "Intel MID platform support"
419 depends on X86_EXTENDED_PLATFORM
421 Select to build a kernel capable of supporting Intel MID platform
422 systems which do not have the PCI legacy interfaces (Moorestown,
423 Medfield). If you are building for a PC class system say N here.
425 if X86_WANT_INTEL_MID
431 bool "Medfield MID platform"
434 depends on X86_IO_APIC
442 select X86_PLATFORM_DEVICES
443 select MFD_INTEL_MSIC
445 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
446 Internet Device(MID) platform.
447 Unlike standard x86 PCs, Medfield does not have many legacy devices
448 nor standard legacy replacement devices/features. e.g. Medfield does
449 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
454 bool "RDC R-321x SoC"
456 depends on X86_EXTENDED_PLATFORM
458 select X86_REBOOTFIXUPS
460 This option is needed for RDC R-321x system-on-chip, also known
462 If you don't have one of these chips, you should say N here.
464 config X86_32_NON_STANDARD
465 bool "Support non-standard 32-bit SMP architectures"
466 depends on X86_32 && SMP
467 depends on X86_EXTENDED_PLATFORM
469 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
470 STA2X11, default subarchitectures. It is intended for a generic
471 binary kernel. If you select them all, kernel will probe it
472 one by one and will fallback to default.
474 # Alphabetically sorted list of Non standard 32 bit platforms
477 bool "NUMAQ (IBM/Sequent)"
478 depends on X86_32_NON_STANDARD
483 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
484 NUMA multiquad box. This changes the way that processors are
485 bootstrapped, and uses Clustered Logical APIC addressing mode instead
486 of Flat Logical. You will need a new lynxer.elf file to flash your
487 firmware with - send email to <Martin.Bligh@us.ibm.com>.
489 config X86_SUPPORTS_MEMORY_FAILURE
491 # MCE code calls memory_failure():
493 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
494 depends on !X86_NUMAQ
495 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
496 depends on X86_64 || !SPARSEMEM
497 select ARCH_SUPPORTS_MEMORY_FAILURE
500 bool "SGI 320/540 (Visual Workstation)"
501 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
502 depends on X86_32_NON_STANDARD
504 The SGI Visual Workstation series is an IA32-based workstation
505 based on SGI systems chips with some legacy PC hardware attached.
507 Say Y here to create a kernel to run on the SGI 320 or 540.
509 A kernel compiled for the Visual Workstation will run on general
510 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
513 bool "STA2X11 Companion Chip Support"
514 depends on X86_32_NON_STANDARD && PCI
515 select X86_DEV_DMA_OPS
519 select ARCH_REQUIRE_GPIOLIB
522 This adds support for boards based on the STA2X11 IO-Hub,
523 a.k.a. "ConneXt". The chip is used in place of the standard
524 PC chipset, so all "standard" peripherals are missing. If this
525 option is selected the kernel will still be able to boot on
526 standard PC machines.
529 bool "Summit/EXA (IBM x440)"
530 depends on X86_32_NON_STANDARD
532 This option is needed for IBM systems that use the Summit/EXA chipset.
533 In particular, it is needed for the x440.
536 bool "Unisys ES7000 IA32 series"
537 depends on X86_32_NON_STANDARD && X86_BIGSMP
539 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
540 supposed to run on an IA32-based Unisys ES7000 system.
543 tristate "Eurobraille/Iris poweroff module"
546 The Iris machines from EuroBraille do not have APM or ACPI support
547 to shut themselves down properly. A special I/O sequence is
548 needed to do so, which is what this module does at
551 This is only for Iris machines from EuroBraille.
555 config SCHED_OMIT_FRAME_POINTER
557 prompt "Single-depth WCHAN output"
560 Calculate simpler /proc/<PID>/wchan values. If this option
561 is disabled then wchan values will recurse back to the
562 caller function. This provides more accurate wchan values,
563 at the expense of slightly more scheduling overhead.
565 If in doubt, say "Y".
567 menuconfig PARAVIRT_GUEST
568 bool "Paravirtualized guest support"
570 Say Y here to get to see options related to running Linux under
571 various hypervisors. This option alone does not add any kernel code.
573 If you say N, all options in this submenu will be skipped and disabled.
577 config PARAVIRT_TIME_ACCOUNTING
578 bool "Paravirtual steal time accounting"
582 Select this option to enable fine granularity task steal time
583 accounting. Time spent executing other tasks in parallel with
584 the current vCPU is discounted from the vCPU power. To account for
585 that, there can be a small performance impact.
587 If in doubt, say N here.
589 source "arch/x86/xen/Kconfig"
592 bool "KVM Guest support (including kvmclock)"
595 select PARAVIRT_CLOCK
596 default y if PARAVIRT_GUEST
598 This option enables various optimizations for running under the KVM
599 hypervisor. It includes a paravirtualized clock, so that instead
600 of relying on a PIT (or probably other) emulation by the
601 underlying device model, the host provides the guest with
602 timing infrastructure such as time of day, and system time
604 source "arch/x86/lguest/Kconfig"
607 bool "Enable paravirtualization code"
609 This changes the kernel so it can modify itself when it is run
610 under a hypervisor, potentially improving performance significantly
611 over full virtualization. However, when run without a hypervisor
612 the kernel is theoretically slower and slightly larger.
614 config PARAVIRT_SPINLOCKS
615 bool "Paravirtualization layer for spinlocks"
616 depends on PARAVIRT && SMP && EXPERIMENTAL
618 Paravirtualized spinlocks allow a pvops backend to replace the
619 spinlock implementation with something virtualization-friendly
620 (for example, block the virtual CPU rather than spinning).
622 Unfortunately the downside is an up to 5% performance hit on
623 native kernels, with various workloads.
625 If you are unsure how to answer this question, answer N.
627 config PARAVIRT_CLOCK
632 config PARAVIRT_DEBUG
633 bool "paravirt-ops debugging"
634 depends on PARAVIRT && DEBUG_KERNEL
636 Enable to debug paravirt_ops internals. Specifically, BUG if
637 a paravirt_op is missing when it is called.
645 This option adds a kernel parameter 'memtest', which allows memtest
647 memtest=0, mean disabled; -- default
648 memtest=1, mean do 1 test pattern;
650 memtest=4, mean do 4 test patterns.
651 If you are unsure how to answer this question, answer N.
653 config X86_SUMMIT_NUMA
655 depends on X86_32 && NUMA && X86_32_NON_STANDARD
657 config X86_CYCLONE_TIMER
659 depends on X86_SUMMIT
661 source "arch/x86/Kconfig.cpu"
665 prompt "HPET Timer Support" if X86_32
667 Use the IA-PC HPET (High Precision Event Timer) to manage
668 time in preference to the PIT and RTC, if a HPET is
670 HPET is the next generation timer replacing legacy 8254s.
671 The HPET provides a stable time base on SMP
672 systems, unlike the TSC, but it is more expensive to access,
673 as it is off-chip. You can find the HPET spec at
674 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
676 You can safely choose Y here. However, HPET will only be
677 activated if the platform and the BIOS support this feature.
678 Otherwise the 8254 will be used for timing services.
680 Choose N to continue using the legacy 8254 timer.
682 config HPET_EMULATE_RTC
684 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
687 def_bool y if X86_INTEL_MID
688 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
690 depends on X86_INTEL_MID && SFI
692 APB timer is the replacement for 8254, HPET on X86 MID platforms.
693 The APBT provides a stable time base on SMP
694 systems, unlike the TSC, but it is more expensive to access,
695 as it is off-chip. APB timers are always running regardless of CPU
696 C states, they are used as per CPU clockevent device when possible.
698 # Mark as expert because too many people got it wrong.
699 # The code disables itself when not needed.
702 bool "Enable DMI scanning" if EXPERT
704 Enabled scanning of DMI to identify machine quirks. Say Y
705 here unless you have verified that your setup is not
706 affected by entries in the DMI blacklist. Required by PNP
710 bool "GART IOMMU support" if EXPERT
713 depends on X86_64 && PCI && AMD_NB
715 Support for full DMA access of devices with 32bit memory access only
716 on systems with more than 3GB. This is usually needed for USB,
717 sound, many IDE/SATA chipsets and some other devices.
718 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
719 based hardware IOMMU and a software bounce buffer based IOMMU used
720 on Intel systems and as fallback.
721 The code is only active when needed (enough memory and limited
722 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
726 bool "IBM Calgary IOMMU support"
728 depends on X86_64 && PCI && EXPERIMENTAL
730 Support for hardware IOMMUs in IBM's xSeries x366 and x460
731 systems. Needed to run systems with more than 3GB of memory
732 properly with 32-bit PCI devices that do not support DAC
733 (Double Address Cycle). Calgary also supports bus level
734 isolation, where all DMAs pass through the IOMMU. This
735 prevents them from going anywhere except their intended
736 destination. This catches hard-to-find kernel bugs and
737 mis-behaving drivers and devices that do not use the DMA-API
738 properly to set up their DMA buffers. The IOMMU can be
739 turned off at boot time with the iommu=off parameter.
740 Normally the kernel will make the right choice by itself.
743 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
745 prompt "Should Calgary be enabled by default?"
746 depends on CALGARY_IOMMU
748 Should Calgary be enabled by default? if you choose 'y', Calgary
749 will be used (if it exists). If you choose 'n', Calgary will not be
750 used even if it exists. If you choose 'n' and would like to use
751 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
754 # need this always selected by IOMMU for the VIA workaround
758 Support for software bounce buffers used on x86-64 systems
759 which don't have a hardware IOMMU. Using this PCI devices
760 which can only access 32-bits of memory can be used on systems
761 with more than 3 GB of memory.
766 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
769 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
770 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
771 select CPUMASK_OFFSTACK
773 Enable maximum number of CPUS and NUMA Nodes for this architecture.
777 int "Maximum number of CPUs" if SMP && !MAXSMP
778 range 2 8 if SMP && X86_32 && !X86_BIGSMP
779 range 2 512 if SMP && !MAXSMP
781 default "4096" if MAXSMP
782 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
785 This allows you to specify the maximum number of CPUs which this
786 kernel will support. The maximum supported value is 512 and the
787 minimum value which makes sense is 2.
789 This is purely to save memory - each supported CPU adds
790 approximately eight kilobytes to the kernel image.
793 bool "SMT (Hyperthreading) scheduler support"
796 SMT scheduler support improves the CPU scheduler's decision making
797 when dealing with Intel Pentium 4 chips with HyperThreading at a
798 cost of slightly increased overhead in some places. If unsure say
803 prompt "Multi-core scheduler support"
806 Multi-core scheduler support improves the CPU scheduler's decision
807 making when dealing with multi-core CPU chips at a cost of slightly
808 increased overhead in some places. If unsure say N here.
810 source "kernel/Kconfig.preempt"
813 bool "Local APIC support on uniprocessors"
814 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
816 A local APIC (Advanced Programmable Interrupt Controller) is an
817 integrated interrupt controller in the CPU. If you have a single-CPU
818 system which has a processor with a local APIC, you can say Y here to
819 enable and use it. If you say Y here even though your machine doesn't
820 have a local APIC, then the kernel will still run with no slowdown at
821 all. The local APIC supports CPU-generated self-interrupts (timer,
822 performance counters), and the NMI watchdog which detects hard
826 bool "IO-APIC support on uniprocessors"
827 depends on X86_UP_APIC
829 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
830 SMP-capable replacement for PC-style interrupt controllers. Most
831 SMP systems and many recent uniprocessor systems have one.
833 If you have a single-CPU system with an IO-APIC, you can say Y here
834 to use it. If you say Y here even though your machine doesn't have
835 an IO-APIC, then the kernel will still run with no slowdown at all.
837 config X86_LOCAL_APIC
839 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
843 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
845 config X86_VISWS_APIC
847 depends on X86_32 && X86_VISWS
849 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
850 bool "Reroute for broken boot IRQs"
851 depends on X86_IO_APIC
853 This option enables a workaround that fixes a source of
854 spurious interrupts. This is recommended when threaded
855 interrupt handling is used on systems where the generation of
856 superfluous "boot interrupts" cannot be disabled.
858 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
859 entry in the chipset's IO-APIC is masked (as, e.g. the RT
860 kernel does during interrupt handling). On chipsets where this
861 boot IRQ generation cannot be disabled, this workaround keeps
862 the original IRQ line masked so that only the equivalent "boot
863 IRQ" is delivered to the CPUs. The workaround also tells the
864 kernel to set up the IRQ handler on the boot IRQ line. In this
865 way only one interrupt is delivered to the kernel. Otherwise
866 the spurious second interrupt may cause the kernel to bring
867 down (vital) interrupt lines.
869 Only affects "broken" chipsets. Interrupt sharing may be
870 increased on these systems.
873 bool "Machine Check / overheating reporting"
876 Machine Check support allows the processor to notify the
877 kernel if it detects a problem (e.g. overheating, data corruption).
878 The action the kernel takes depends on the severity of the problem,
879 ranging from warning messages to halting the machine.
883 prompt "Intel MCE features"
884 depends on X86_MCE && X86_LOCAL_APIC
886 Additional support for intel specific MCE features such as
891 prompt "AMD MCE features"
892 depends on X86_MCE && X86_LOCAL_APIC
894 Additional support for AMD specific MCE features such as
895 the DRAM Error Threshold.
897 config X86_ANCIENT_MCE
898 bool "Support for old Pentium 5 / WinChip machine checks"
899 depends on X86_32 && X86_MCE
901 Include support for machine check handling on old Pentium 5 or WinChip
902 systems. These typically need to be enabled explicitely on the command
905 config X86_MCE_THRESHOLD
906 depends on X86_MCE_AMD || X86_MCE_INTEL
909 config X86_MCE_INJECT
911 tristate "Machine check injector support"
913 Provide support for injecting machine checks for testing purposes.
914 If you don't know what a machine check is and you don't do kernel
915 QA it is safe to say n.
917 config X86_THERMAL_VECTOR
919 depends on X86_MCE_INTEL
922 bool "Enable VM86 support" if EXPERT
926 This option is required by programs like DOSEMU to run 16-bit legacy
927 code on X86 processors. It also may be needed by software like
928 XFree86 to initialize some video cards via BIOS. Disabling this
929 option saves about 6k.
932 tristate "Toshiba Laptop support"
935 This adds a driver to safely access the System Management Mode of
936 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
937 not work on models with a Phoenix BIOS. The System Management Mode
938 is used to set the BIOS and power saving options on Toshiba portables.
940 For information on utilities to make use of this driver see the
941 Toshiba Linux utilities web site at:
942 <http://www.buzzard.org.uk/toshiba/>.
944 Say Y if you intend to run this kernel on a Toshiba portable.
948 tristate "Dell laptop support"
951 This adds a driver to safely access the System Management Mode
952 of the CPU on the Dell Inspiron 8000. The System Management Mode
953 is used to read cpu temperature and cooling fan status and to
954 control the fans on the I8K portables.
956 This driver has been tested only on the Inspiron 8000 but it may
957 also work with other Dell laptops. You can force loading on other
958 models by passing the parameter `force=1' to the module. Use at
961 For information on utilities to make use of this driver see the
962 I8K Linux utilities web site at:
963 <http://people.debian.org/~dz/i8k/>
965 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
968 config X86_REBOOTFIXUPS
969 bool "Enable X86 board specific fixups for reboot"
972 This enables chipset and/or board specific fixups to be done
973 in order to get reboot to work correctly. This is only needed on
974 some combinations of hardware and BIOS. The symptom, for which
975 this config is intended, is when reboot ends with a stalled/hung
978 Currently, the only fixup is for the Geode machines using
979 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
981 Say Y if you want to enable the fixup. Currently, it's safe to
982 enable this option even if you don't need it.
986 tristate "CPU microcode loading support"
990 If you say Y here, you will be able to update the microcode on
991 certain Intel and AMD processors. The Intel support is for the
992 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
993 Xeon etc. The AMD support is for families 0x10 and later. You will
994 obviously need the actual microcode binary data itself which is not
995 shipped with the Linux kernel.
997 This option selects the general module only, you need to select
998 at least one vendor specific module as well.
1000 To compile this driver as a module, choose M here: the module
1001 will be called microcode.
1003 config MICROCODE_INTEL
1004 bool "Intel microcode loading support"
1005 depends on MICROCODE
1009 This options enables microcode patch loading support for Intel
1012 For latest news and information on obtaining all the required
1013 Intel ingredients for this driver, check:
1014 <http://www.urbanmyth.org/microcode/>.
1016 config MICROCODE_AMD
1017 bool "AMD microcode loading support"
1018 depends on MICROCODE
1021 If you select this option, microcode patch loading support for AMD
1022 processors will be enabled.
1024 config MICROCODE_OLD_INTERFACE
1026 depends on MICROCODE
1029 tristate "/dev/cpu/*/msr - Model-specific register support"
1031 This device gives privileged processes access to the x86
1032 Model-Specific Registers (MSRs). It is a character device with
1033 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1034 MSR accesses are directed to a specific CPU on multi-processor
1038 tristate "/dev/cpu/*/cpuid - CPU information support"
1040 This device gives processes access to the x86 CPUID instruction to
1041 be executed on a specific processor. It is a character device
1042 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1046 prompt "High Memory Support"
1047 default HIGHMEM64G if X86_NUMAQ
1053 depends on !X86_NUMAQ
1055 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1056 However, the address space of 32-bit x86 processors is only 4
1057 Gigabytes large. That means that, if you have a large amount of
1058 physical memory, not all of it can be "permanently mapped" by the
1059 kernel. The physical memory that's not permanently mapped is called
1062 If you are compiling a kernel which will never run on a machine with
1063 more than 1 Gigabyte total physical RAM, answer "off" here (default
1064 choice and suitable for most users). This will result in a "3GB/1GB"
1065 split: 3GB are mapped so that each process sees a 3GB virtual memory
1066 space and the remaining part of the 4GB virtual memory space is used
1067 by the kernel to permanently map as much physical memory as
1070 If the machine has between 1 and 4 Gigabytes physical RAM, then
1073 If more than 4 Gigabytes is used then answer "64GB" here. This
1074 selection turns Intel PAE (Physical Address Extension) mode on.
1075 PAE implements 3-level paging on IA32 processors. PAE is fully
1076 supported by Linux, PAE mode is implemented on all recent Intel
1077 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1078 then the kernel will not boot on CPUs that don't support PAE!
1080 The actual amount of total physical memory will either be
1081 auto detected or can be forced by using a kernel command line option
1082 such as "mem=256M". (Try "man bootparam" or see the documentation of
1083 your boot loader (lilo or loadlin) about how to pass options to the
1084 kernel at boot time.)
1086 If unsure, say "off".
1090 depends on !X86_NUMAQ
1092 Select this if you have a 32-bit processor and between 1 and 4
1093 gigabytes of physical RAM.
1097 depends on !M386 && !M486
1100 Select this if you have a 32-bit processor and more than 4
1101 gigabytes of physical RAM.
1106 depends on EXPERIMENTAL
1107 prompt "Memory split" if EXPERT
1111 Select the desired split between kernel and user memory.
1113 If the address range available to the kernel is less than the
1114 physical memory installed, the remaining memory will be available
1115 as "high memory". Accessing high memory is a little more costly
1116 than low memory, as it needs to be mapped into the kernel first.
1117 Note that increasing the kernel address space limits the range
1118 available to user programs, making the address space there
1119 tighter. Selecting anything other than the default 3G/1G split
1120 will also likely make your kernel incompatible with binary-only
1123 If you are not absolutely sure what you are doing, leave this
1127 bool "3G/1G user/kernel split"
1128 config VMSPLIT_3G_OPT
1130 bool "3G/1G user/kernel split (for full 1G low memory)"
1132 bool "2G/2G user/kernel split"
1133 config VMSPLIT_2G_OPT
1135 bool "2G/2G user/kernel split (for full 2G low memory)"
1137 bool "1G/3G user/kernel split"
1142 default 0xB0000000 if VMSPLIT_3G_OPT
1143 default 0x80000000 if VMSPLIT_2G
1144 default 0x78000000 if VMSPLIT_2G_OPT
1145 default 0x40000000 if VMSPLIT_1G
1151 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1154 bool "PAE (Physical Address Extension) Support"
1155 depends on X86_32 && !HIGHMEM4G
1157 PAE is required for NX support, and furthermore enables
1158 larger swapspace support for non-overcommit purposes. It
1159 has the cost of more pagetable lookup overhead, and also
1160 consumes more pagetable space per process.
1162 config ARCH_PHYS_ADDR_T_64BIT
1164 depends on X86_64 || X86_PAE
1166 config ARCH_DMA_ADDR_T_64BIT
1168 depends on X86_64 || HIGHMEM64G
1170 config DIRECT_GBPAGES
1171 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1175 Allow the kernel linear mapping to use 1GB pages on CPUs that
1176 support it. This can improve the kernel's performance a tiny bit by
1177 reducing TLB pressure. If in doubt, say "Y".
1179 # Common NUMA Features
1181 bool "Numa Memory Allocation and Scheduler Support"
1183 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1184 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1186 Enable NUMA (Non Uniform Memory Access) support.
1188 The kernel will try to allocate memory used by a CPU on the
1189 local memory controller of the CPU and add some more
1190 NUMA awareness to the kernel.
1192 For 64-bit this is recommended if the system is Intel Core i7
1193 (or later), AMD Opteron, or EM64T NUMA.
1195 For 32-bit this is only needed on (rare) 32-bit-only platforms
1196 that support NUMA topologies, such as NUMAQ / Summit, or if you
1197 boot a 32-bit kernel on a 64-bit NUMA platform.
1199 Otherwise, you should say N.
1201 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1202 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1206 prompt "Old style AMD Opteron NUMA detection"
1207 depends on X86_64 && NUMA && PCI
1209 Enable AMD NUMA node topology detection. You should say Y here if
1210 you have a multi processor AMD system. This uses an old method to
1211 read the NUMA configuration directly from the builtin Northbridge
1212 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1213 which also takes priority if both are compiled in.
1215 config X86_64_ACPI_NUMA
1217 prompt "ACPI NUMA detection"
1218 depends on X86_64 && NUMA && ACPI && PCI
1221 Enable ACPI SRAT based node topology detection.
1223 # Some NUMA nodes have memory ranges that span
1224 # other nodes. Even though a pfn is valid and
1225 # between a node's start and end pfns, it may not
1226 # reside on that node. See memmap_init_zone()
1228 config NODES_SPAN_OTHER_NODES
1230 depends on X86_64_ACPI_NUMA
1233 bool "NUMA emulation"
1236 Enable NUMA emulation. A flat machine will be split
1237 into virtual nodes when booted with "numa=fake=N", where N is the
1238 number of nodes. This is only useful for debugging.
1241 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1243 default "10" if MAXSMP
1244 default "6" if X86_64
1245 default "4" if X86_NUMAQ
1247 depends on NEED_MULTIPLE_NODES
1249 Specify the maximum number of NUMA Nodes available on the target
1250 system. Increases memory reserved to accommodate various tables.
1252 config HAVE_ARCH_ALLOC_REMAP
1254 depends on X86_32 && NUMA
1256 config ARCH_HAVE_MEMORY_PRESENT
1258 depends on X86_32 && DISCONTIGMEM
1260 config NEED_NODE_MEMMAP_SIZE
1262 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1264 config ARCH_FLATMEM_ENABLE
1266 depends on X86_32 && !NUMA
1268 config ARCH_DISCONTIGMEM_ENABLE
1270 depends on NUMA && X86_32
1272 config ARCH_DISCONTIGMEM_DEFAULT
1274 depends on NUMA && X86_32
1276 config ARCH_SPARSEMEM_ENABLE
1278 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1279 select SPARSEMEM_STATIC if X86_32
1280 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1282 config ARCH_SPARSEMEM_DEFAULT
1286 config ARCH_SELECT_MEMORY_MODEL
1288 depends on ARCH_SPARSEMEM_ENABLE
1290 config ARCH_MEMORY_PROBE
1292 depends on X86_64 && MEMORY_HOTPLUG
1294 config ARCH_PROC_KCORE_TEXT
1296 depends on X86_64 && PROC_KCORE
1298 config ILLEGAL_POINTER_VALUE
1301 default 0xdead000000000000 if X86_64
1306 bool "Allocate 3rd-level pagetables from highmem"
1309 The VM uses one page table entry for each page of physical memory.
1310 For systems with a lot of RAM, this can be wasteful of precious
1311 low memory. Setting this option will put user-space page table
1312 entries in high memory.
1314 config X86_CHECK_BIOS_CORRUPTION
1315 bool "Check for low memory corruption"
1317 Periodically check for memory corruption in low memory, which
1318 is suspected to be caused by BIOS. Even when enabled in the
1319 configuration, it is disabled at runtime. Enable it by
1320 setting "memory_corruption_check=1" on the kernel command
1321 line. By default it scans the low 64k of memory every 60
1322 seconds; see the memory_corruption_check_size and
1323 memory_corruption_check_period parameters in
1324 Documentation/kernel-parameters.txt to adjust this.
1326 When enabled with the default parameters, this option has
1327 almost no overhead, as it reserves a relatively small amount
1328 of memory and scans it infrequently. It both detects corruption
1329 and prevents it from affecting the running system.
1331 It is, however, intended as a diagnostic tool; if repeatable
1332 BIOS-originated corruption always affects the same memory,
1333 you can use memmap= to prevent the kernel from using that
1336 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1337 bool "Set the default setting of memory_corruption_check"
1338 depends on X86_CHECK_BIOS_CORRUPTION
1341 Set whether the default state of memory_corruption_check is
1344 config X86_RESERVE_LOW
1345 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1349 Specify the amount of low memory to reserve for the BIOS.
1351 The first page contains BIOS data structures that the kernel
1352 must not use, so that page must always be reserved.
1354 By default we reserve the first 64K of physical RAM, as a
1355 number of BIOSes are known to corrupt that memory range
1356 during events such as suspend/resume or monitor cable
1357 insertion, so it must not be used by the kernel.
1359 You can set this to 4 if you are absolutely sure that you
1360 trust the BIOS to get all its memory reservations and usages
1361 right. If you know your BIOS have problems beyond the
1362 default 64K area, you can set this to 640 to avoid using the
1363 entire low memory range.
1365 If you have doubts about the BIOS (e.g. suspend/resume does
1366 not work or there's kernel crashes after certain hardware
1367 hotplug events) then you might want to enable
1368 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1369 typical corruption patterns.
1371 Leave this to the default value of 64 if you are unsure.
1373 config MATH_EMULATION
1375 prompt "Math emulation" if X86_32
1377 Linux can emulate a math coprocessor (used for floating point
1378 operations) if you don't have one. 486DX and Pentium processors have
1379 a math coprocessor built in, 486SX and 386 do not, unless you added
1380 a 487DX or 387, respectively. (The messages during boot time can
1381 give you some hints here ["man dmesg"].) Everyone needs either a
1382 coprocessor or this emulation.
1384 If you don't have a math coprocessor, you need to say Y here; if you
1385 say Y here even though you have a coprocessor, the coprocessor will
1386 be used nevertheless. (This behavior can be changed with the kernel
1387 command line option "no387", which comes handy if your coprocessor
1388 is broken. Try "man bootparam" or see the documentation of your boot
1389 loader (lilo or loadlin) about how to pass options to the kernel at
1390 boot time.) This means that it is a good idea to say Y here if you
1391 intend to use this kernel on different machines.
1393 More information about the internals of the Linux math coprocessor
1394 emulation can be found in <file:arch/x86/math-emu/README>.
1396 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1397 kernel, it won't hurt.
1401 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1403 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1404 the Memory Type Range Registers (MTRRs) may be used to control
1405 processor access to memory ranges. This is most useful if you have
1406 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1407 allows bus write transfers to be combined into a larger transfer
1408 before bursting over the PCI/AGP bus. This can increase performance
1409 of image write operations 2.5 times or more. Saying Y here creates a
1410 /proc/mtrr file which may be used to manipulate your processor's
1411 MTRRs. Typically the X server should use this.
1413 This code has a reasonably generic interface so that similar
1414 control registers on other processors can be easily supported
1417 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1418 Registers (ARRs) which provide a similar functionality to MTRRs. For
1419 these, the ARRs are used to emulate the MTRRs.
1420 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1421 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1422 write-combining. All of these processors are supported by this code
1423 and it makes sense to say Y here if you have one of them.
1425 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1426 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1427 can lead to all sorts of problems, so it's good to say Y here.
1429 You can safely say Y even if your machine doesn't have MTRRs, you'll
1430 just add about 9 KB to your kernel.
1432 See <file:Documentation/x86/mtrr.txt> for more information.
1434 config MTRR_SANITIZER
1436 prompt "MTRR cleanup support"
1439 Convert MTRR layout from continuous to discrete, so X drivers can
1440 add writeback entries.
1442 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1443 The largest mtrr entry size for a continuous block can be set with
1448 config MTRR_SANITIZER_ENABLE_DEFAULT
1449 int "MTRR cleanup enable value (0-1)"
1452 depends on MTRR_SANITIZER
1454 Enable mtrr cleanup default value
1456 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1457 int "MTRR cleanup spare reg num (0-7)"
1460 depends on MTRR_SANITIZER
1462 mtrr cleanup spare entries default, it can be changed via
1463 mtrr_spare_reg_nr=N on the kernel command line.
1467 prompt "x86 PAT support" if EXPERT
1470 Use PAT attributes to setup page level cache control.
1472 PATs are the modern equivalents of MTRRs and are much more
1473 flexible than MTRRs.
1475 Say N here if you see bootup problems (boot crash, boot hang,
1476 spontaneous reboots) or a non-working video driver.
1480 config ARCH_USES_PG_UNCACHED
1486 prompt "x86 architectural random number generator" if EXPERT
1488 Enable the x86 architectural RDRAND instruction
1489 (Intel Bull Mountain technology) to generate random numbers.
1490 If supported, this is a high bandwidth, cryptographically
1491 secure hardware random number generator.
1495 prompt "Supervisor Mode Access Prevention" if EXPERT
1497 Supervisor Mode Access Prevention (SMAP) is a security
1498 feature in newer Intel processors. There is a small
1499 performance cost if this enabled and turned on; there is
1500 also a small increase in the kernel size if this is enabled.
1505 bool "EFI runtime service support"
1508 This enables the kernel to use EFI runtime services that are
1509 available (such as the EFI variable services).
1511 This option is only useful on systems that have EFI firmware.
1512 In addition, you should use the latest ELILO loader available
1513 at <http://elilo.sourceforge.net> in order to take advantage
1514 of EFI runtime services. However, even with this option, the
1515 resultant kernel should continue to boot on existing non-EFI
1519 bool "EFI stub support"
1522 This kernel feature allows a bzImage to be loaded directly
1523 by EFI firmware without the use of a bootloader.
1525 See Documentation/x86/efi-stub.txt for more information.
1529 prompt "Enable seccomp to safely compute untrusted bytecode"
1531 This kernel feature is useful for number crunching applications
1532 that may need to compute untrusted bytecode during their
1533 execution. By using pipes or other transports made available to
1534 the process as file descriptors supporting the read/write
1535 syscalls, it's possible to isolate those applications in
1536 their own address space using seccomp. Once seccomp is
1537 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1538 and the task is only allowed to execute a few safe syscalls
1539 defined by each seccomp mode.
1541 If unsure, say Y. Only embedded should say N here.
1543 config CC_STACKPROTECTOR
1544 bool "Enable -fstack-protector buffer overflow detection"
1546 This option turns on the -fstack-protector GCC feature. This
1547 feature puts, at the beginning of functions, a canary value on
1548 the stack just before the return address, and validates
1549 the value just before actually returning. Stack based buffer
1550 overflows (that need to overwrite this return address) now also
1551 overwrite the canary, which gets detected and the attack is then
1552 neutralized via a kernel panic.
1554 This feature requires gcc version 4.2 or above, or a distribution
1555 gcc with the feature backported. Older versions are automatically
1556 detected and for those versions, this configuration option is
1557 ignored. (and a warning is printed during bootup)
1559 source kernel/Kconfig.hz
1562 bool "kexec system call"
1564 kexec is a system call that implements the ability to shutdown your
1565 current kernel, and to start another kernel. It is like a reboot
1566 but it is independent of the system firmware. And like a reboot
1567 you can start any kernel with it, not just Linux.
1569 The name comes from the similarity to the exec system call.
1571 It is an ongoing process to be certain the hardware in a machine
1572 is properly shutdown, so do not be surprised if this code does not
1573 initially work for you. It may help to enable device hotplugging
1574 support. As of this writing the exact hardware interface is
1575 strongly in flux, so no good recommendation can be made.
1578 bool "kernel crash dumps"
1579 depends on X86_64 || (X86_32 && HIGHMEM)
1581 Generate crash dump after being started by kexec.
1582 This should be normally only set in special crash dump kernels
1583 which are loaded in the main kernel with kexec-tools into
1584 a specially reserved region and then later executed after
1585 a crash by kdump/kexec. The crash dump kernel must be compiled
1586 to a memory address not used by the main kernel or BIOS using
1587 PHYSICAL_START, or it must be built as a relocatable image
1588 (CONFIG_RELOCATABLE=y).
1589 For more details see Documentation/kdump/kdump.txt
1592 bool "kexec jump (EXPERIMENTAL)"
1593 depends on EXPERIMENTAL
1594 depends on KEXEC && HIBERNATION
1596 Jump between original kernel and kexeced kernel and invoke
1597 code in physical address mode via KEXEC
1599 config PHYSICAL_START
1600 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1603 This gives the physical address where the kernel is loaded.
1605 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1606 bzImage will decompress itself to above physical address and
1607 run from there. Otherwise, bzImage will run from the address where
1608 it has been loaded by the boot loader and will ignore above physical
1611 In normal kdump cases one does not have to set/change this option
1612 as now bzImage can be compiled as a completely relocatable image
1613 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1614 address. This option is mainly useful for the folks who don't want
1615 to use a bzImage for capturing the crash dump and want to use a
1616 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1617 to be specifically compiled to run from a specific memory area
1618 (normally a reserved region) and this option comes handy.
1620 So if you are using bzImage for capturing the crash dump,
1621 leave the value here unchanged to 0x1000000 and set
1622 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1623 for capturing the crash dump change this value to start of
1624 the reserved region. In other words, it can be set based on
1625 the "X" value as specified in the "crashkernel=YM@XM"
1626 command line boot parameter passed to the panic-ed
1627 kernel. Please take a look at Documentation/kdump/kdump.txt
1628 for more details about crash dumps.
1630 Usage of bzImage for capturing the crash dump is recommended as
1631 one does not have to build two kernels. Same kernel can be used
1632 as production kernel and capture kernel. Above option should have
1633 gone away after relocatable bzImage support is introduced. But it
1634 is present because there are users out there who continue to use
1635 vmlinux for dump capture. This option should go away down the
1638 Don't change this unless you know what you are doing.
1641 bool "Build a relocatable kernel"
1644 This builds a kernel image that retains relocation information
1645 so it can be loaded someplace besides the default 1MB.
1646 The relocations tend to make the kernel binary about 10% larger,
1647 but are discarded at runtime.
1649 One use is for the kexec on panic case where the recovery kernel
1650 must live at a different physical address than the primary
1653 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1654 it has been loaded at and the compile time physical address
1655 (CONFIG_PHYSICAL_START) is ignored.
1657 # Relocation on x86-32 needs some additional build support
1658 config X86_NEED_RELOCS
1660 depends on X86_32 && RELOCATABLE
1662 config PHYSICAL_ALIGN
1663 hex "Alignment value to which kernel should be aligned" if X86_32
1665 range 0x2000 0x1000000
1667 This value puts the alignment restrictions on physical address
1668 where kernel is loaded and run from. Kernel is compiled for an
1669 address which meets above alignment restriction.
1671 If bootloader loads the kernel at a non-aligned address and
1672 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1673 address aligned to above value and run from there.
1675 If bootloader loads the kernel at a non-aligned address and
1676 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1677 load address and decompress itself to the address it has been
1678 compiled for and run from there. The address for which kernel is
1679 compiled already meets above alignment restrictions. Hence the
1680 end result is that kernel runs from a physical address meeting
1681 above alignment restrictions.
1683 Don't change this unless you know what you are doing.
1686 bool "Support for hot-pluggable CPUs"
1687 depends on SMP && HOTPLUG
1689 Say Y here to allow turning CPUs off and on. CPUs can be
1690 controlled through /sys/devices/system/cpu.
1691 ( Note: power management support will enable this option
1692 automatically on SMP systems. )
1693 Say N if you want to disable CPU hotplug.
1697 prompt "Compat VDSO support"
1698 depends on X86_32 || IA32_EMULATION
1700 Map the 32-bit VDSO to the predictable old-style address too.
1702 Say N here if you are running a sufficiently recent glibc
1703 version (2.3.3 or later), to remove the high-mapped
1704 VDSO mapping and to exclusively use the randomized VDSO.
1709 bool "Built-in kernel command line"
1711 Allow for specifying boot arguments to the kernel at
1712 build time. On some systems (e.g. embedded ones), it is
1713 necessary or convenient to provide some or all of the
1714 kernel boot arguments with the kernel itself (that is,
1715 to not rely on the boot loader to provide them.)
1717 To compile command line arguments into the kernel,
1718 set this option to 'Y', then fill in the
1719 the boot arguments in CONFIG_CMDLINE.
1721 Systems with fully functional boot loaders (i.e. non-embedded)
1722 should leave this option set to 'N'.
1725 string "Built-in kernel command string"
1726 depends on CMDLINE_BOOL
1729 Enter arguments here that should be compiled into the kernel
1730 image and used at boot time. If the boot loader provides a
1731 command line at boot time, it is appended to this string to
1732 form the full kernel command line, when the system boots.
1734 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1735 change this behavior.
1737 In most cases, the command line (whether built-in or provided
1738 by the boot loader) should specify the device for the root
1741 config CMDLINE_OVERRIDE
1742 bool "Built-in command line overrides boot loader arguments"
1743 depends on CMDLINE_BOOL
1745 Set this option to 'Y' to have the kernel ignore the boot loader
1746 command line, and use ONLY the built-in command line.
1748 This is used to work around broken boot loaders. This should
1749 be set to 'N' under normal conditions.
1753 config ARCH_ENABLE_MEMORY_HOTPLUG
1755 depends on X86_64 || (X86_32 && HIGHMEM)
1757 config ARCH_ENABLE_MEMORY_HOTREMOVE
1759 depends on MEMORY_HOTPLUG
1761 config USE_PERCPU_NUMA_NODE_ID
1765 menu "Power management and ACPI options"
1767 config ARCH_HIBERNATION_HEADER
1769 depends on X86_64 && HIBERNATION
1771 source "kernel/power/Kconfig"
1773 source "drivers/acpi/Kconfig"
1775 source "drivers/sfi/Kconfig"
1782 tristate "APM (Advanced Power Management) BIOS support"
1783 depends on X86_32 && PM_SLEEP
1785 APM is a BIOS specification for saving power using several different
1786 techniques. This is mostly useful for battery powered laptops with
1787 APM compliant BIOSes. If you say Y here, the system time will be
1788 reset after a RESUME operation, the /proc/apm device will provide
1789 battery status information, and user-space programs will receive
1790 notification of APM "events" (e.g. battery status change).
1792 If you select "Y" here, you can disable actual use of the APM
1793 BIOS by passing the "apm=off" option to the kernel at boot time.
1795 Note that the APM support is almost completely disabled for
1796 machines with more than one CPU.
1798 In order to use APM, you will need supporting software. For location
1799 and more information, read <file:Documentation/power/apm-acpi.txt>
1800 and the Battery Powered Linux mini-HOWTO, available from
1801 <http://www.tldp.org/docs.html#howto>.
1803 This driver does not spin down disk drives (see the hdparm(8)
1804 manpage ("man 8 hdparm") for that), and it doesn't turn off
1805 VESA-compliant "green" monitors.
1807 This driver does not support the TI 4000M TravelMate and the ACER
1808 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1809 desktop machines also don't have compliant BIOSes, and this driver
1810 may cause those machines to panic during the boot phase.
1812 Generally, if you don't have a battery in your machine, there isn't
1813 much point in using this driver and you should say N. If you get
1814 random kernel OOPSes or reboots that don't seem to be related to
1815 anything, try disabling/enabling this option (or disabling/enabling
1818 Some other things you should try when experiencing seemingly random,
1821 1) make sure that you have enough swap space and that it is
1823 2) pass the "no-hlt" option to the kernel
1824 3) switch on floating point emulation in the kernel and pass
1825 the "no387" option to the kernel
1826 4) pass the "floppy=nodma" option to the kernel
1827 5) pass the "mem=4M" option to the kernel (thereby disabling
1828 all but the first 4 MB of RAM)
1829 6) make sure that the CPU is not over clocked.
1830 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1831 8) disable the cache from your BIOS settings
1832 9) install a fan for the video card or exchange video RAM
1833 10) install a better fan for the CPU
1834 11) exchange RAM chips
1835 12) exchange the motherboard.
1837 To compile this driver as a module, choose M here: the
1838 module will be called apm.
1842 config APM_IGNORE_USER_SUSPEND
1843 bool "Ignore USER SUSPEND"
1845 This option will ignore USER SUSPEND requests. On machines with a
1846 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1847 series notebooks, it is necessary to say Y because of a BIOS bug.
1849 config APM_DO_ENABLE
1850 bool "Enable PM at boot time"
1852 Enable APM features at boot time. From page 36 of the APM BIOS
1853 specification: "When disabled, the APM BIOS does not automatically
1854 power manage devices, enter the Standby State, enter the Suspend
1855 State, or take power saving steps in response to CPU Idle calls."
1856 This driver will make CPU Idle calls when Linux is idle (unless this
1857 feature is turned off -- see "Do CPU IDLE calls", below). This
1858 should always save battery power, but more complicated APM features
1859 will be dependent on your BIOS implementation. You may need to turn
1860 this option off if your computer hangs at boot time when using APM
1861 support, or if it beeps continuously instead of suspending. Turn
1862 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1863 T400CDT. This is off by default since most machines do fine without
1867 bool "Make CPU Idle calls when idle"
1869 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1870 On some machines, this can activate improved power savings, such as
1871 a slowed CPU clock rate, when the machine is idle. These idle calls
1872 are made after the idle loop has run for some length of time (e.g.,
1873 333 mS). On some machines, this will cause a hang at boot time or
1874 whenever the CPU becomes idle. (On machines with more than one CPU,
1875 this option does nothing.)
1877 config APM_DISPLAY_BLANK
1878 bool "Enable console blanking using APM"
1880 Enable console blanking using the APM. Some laptops can use this to
1881 turn off the LCD backlight when the screen blanker of the Linux
1882 virtual console blanks the screen. Note that this is only used by
1883 the virtual console screen blanker, and won't turn off the backlight
1884 when using the X Window system. This also doesn't have anything to
1885 do with your VESA-compliant power-saving monitor. Further, this
1886 option doesn't work for all laptops -- it might not turn off your
1887 backlight at all, or it might print a lot of errors to the console,
1888 especially if you are using gpm.
1890 config APM_ALLOW_INTS
1891 bool "Allow interrupts during APM BIOS calls"
1893 Normally we disable external interrupts while we are making calls to
1894 the APM BIOS as a measure to lessen the effects of a badly behaving
1895 BIOS implementation. The BIOS should reenable interrupts if it
1896 needs to. Unfortunately, some BIOSes do not -- especially those in
1897 many of the newer IBM Thinkpads. If you experience hangs when you
1898 suspend, try setting this to Y. Otherwise, say N.
1902 source "drivers/cpufreq/Kconfig"
1904 source "drivers/cpuidle/Kconfig"
1906 source "drivers/idle/Kconfig"
1911 menu "Bus options (PCI etc.)"
1916 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1918 Find out whether you have a PCI motherboard. PCI is the name of a
1919 bus system, i.e. the way the CPU talks to the other stuff inside
1920 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1921 VESA. If you have PCI, say Y, otherwise N.
1924 prompt "PCI access mode"
1925 depends on X86_32 && PCI
1928 On PCI systems, the BIOS can be used to detect the PCI devices and
1929 determine their configuration. However, some old PCI motherboards
1930 have BIOS bugs and may crash if this is done. Also, some embedded
1931 PCI-based systems don't have any BIOS at all. Linux can also try to
1932 detect the PCI hardware directly without using the BIOS.
1934 With this option, you can specify how Linux should detect the
1935 PCI devices. If you choose "BIOS", the BIOS will be used,
1936 if you choose "Direct", the BIOS won't be used, and if you
1937 choose "MMConfig", then PCI Express MMCONFIG will be used.
1938 If you choose "Any", the kernel will try MMCONFIG, then the
1939 direct access method and falls back to the BIOS if that doesn't
1940 work. If unsure, go with the default, which is "Any".
1945 config PCI_GOMMCONFIG
1962 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1964 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1967 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1971 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1975 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1979 depends on PCI && XEN
1987 bool "Support mmconfig PCI config space access"
1988 depends on X86_64 && PCI && ACPI
1990 config PCI_CNB20LE_QUIRK
1991 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1992 depends on PCI && EXPERIMENTAL
1994 Read the PCI windows out of the CNB20LE host bridge. This allows
1995 PCI hotplug to work on systems with the CNB20LE chipset which do
1998 There's no public spec for this chipset, and this functionality
1999 is known to be incomplete.
2001 You should say N unless you know you need this.
2003 source "drivers/pci/pcie/Kconfig"
2005 source "drivers/pci/Kconfig"
2007 # x86_64 have no ISA slots, but can have ISA-style DMA.
2009 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2012 Enables ISA-style DMA support for devices requiring such controllers.
2020 Find out whether you have ISA slots on your motherboard. ISA is the
2021 name of a bus system, i.e. the way the CPU talks to the other stuff
2022 inside your box. Other bus systems are PCI, EISA, MicroChannel
2023 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2024 newer boards don't support it. If you have ISA, say Y, otherwise N.
2030 The Extended Industry Standard Architecture (EISA) bus was
2031 developed as an open alternative to the IBM MicroChannel bus.
2033 The EISA bus provided some of the features of the IBM MicroChannel
2034 bus while maintaining backward compatibility with cards made for
2035 the older ISA bus. The EISA bus saw limited use between 1988 and
2036 1995 when it was made obsolete by the PCI bus.
2038 Say Y here if you are building a kernel for an EISA-based machine.
2042 source "drivers/eisa/Kconfig"
2045 tristate "NatSemi SCx200 support"
2047 This provides basic support for National Semiconductor's
2048 (now AMD's) Geode processors. The driver probes for the
2049 PCI-IDs of several on-chip devices, so its a good dependency
2050 for other scx200_* drivers.
2052 If compiled as a module, the driver is named scx200.
2054 config SCx200HR_TIMER
2055 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2059 This driver provides a clocksource built upon the on-chip
2060 27MHz high-resolution timer. Its also a workaround for
2061 NSC Geode SC-1100's buggy TSC, which loses time when the
2062 processor goes idle (as is done by the scheduler). The
2063 other workaround is idle=poll boot option.
2066 bool "One Laptop Per Child support"
2073 Add support for detecting the unique features of the OLPC
2077 bool "OLPC XO-1 Power Management"
2078 depends on OLPC && MFD_CS5535 && PM_SLEEP
2081 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2084 bool "OLPC XO-1 Real Time Clock"
2085 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2087 Add support for the XO-1 real time clock, which can be used as a
2088 programmable wakeup source.
2091 bool "OLPC XO-1 SCI extras"
2092 depends on OLPC && OLPC_XO1_PM
2097 Add support for SCI-based features of the OLPC XO-1 laptop:
2098 - EC-driven system wakeups
2102 - AC adapter status updates
2103 - Battery status updates
2105 config OLPC_XO15_SCI
2106 bool "OLPC XO-1.5 SCI extras"
2107 depends on OLPC && ACPI
2110 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2111 - EC-driven system wakeups
2112 - AC adapter status updates
2113 - Battery status updates
2116 bool "PCEngines ALIX System Support (LED setup)"
2119 This option enables system support for the PCEngines ALIX.
2120 At present this just sets up LEDs for GPIO control on
2121 ALIX2/3/6 boards. However, other system specific setup should
2124 Note: You must still enable the drivers for GPIO and LED support
2125 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2127 Note: You have to set alix.force=1 for boards with Award BIOS.
2130 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2133 This option enables system support for the Soekris Engineering net5501.
2136 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2140 This option enables system support for the Traverse Technologies GEOS.
2146 depends on CPU_SUP_AMD && PCI
2148 source "drivers/pcmcia/Kconfig"
2150 source "drivers/pci/hotplug/Kconfig"
2153 bool "RapidIO support"
2157 If you say Y here, the kernel will include drivers and
2158 infrastructure code to support RapidIO interconnect devices.
2160 source "drivers/rapidio/Kconfig"
2165 menu "Executable file formats / Emulations"
2167 source "fs/Kconfig.binfmt"
2169 config IA32_EMULATION
2170 bool "IA32 Emulation"
2172 select COMPAT_BINFMT_ELF
2175 Include code to run legacy 32-bit programs under a
2176 64-bit kernel. You should likely turn this on, unless you're
2177 100% sure that you don't have any 32-bit programs left.
2180 tristate "IA32 a.out support"
2181 depends on IA32_EMULATION
2183 Support old a.out binaries in the 32bit emulation.
2186 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2187 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2189 Include code to run binaries for the x32 native 32-bit ABI
2190 for 64-bit processors. An x32 process gets access to the
2191 full 64-bit register file and wide data path while leaving
2192 pointers at 32 bits for smaller memory footprint.
2194 You will need a recent binutils (2.22 or later) with
2195 elf32_x86_64 support enabled to compile a kernel with this
2200 depends on IA32_EMULATION || X86_X32
2201 select ARCH_WANT_OLD_COMPAT_IPC
2204 config COMPAT_FOR_U64_ALIGNMENT
2207 config SYSVIPC_COMPAT
2219 config HAVE_ATOMIC_IOMAP
2223 config HAVE_TEXT_POKE_SMP
2225 select STOP_MACHINE if SMP
2227 config X86_DEV_DMA_OPS
2229 depends on X86_64 || STA2X11
2231 config X86_DMA_REMAP
2235 source "net/Kconfig"
2237 source "drivers/Kconfig"
2239 source "drivers/firmware/Kconfig"
2243 source "arch/x86/Kconfig.debug"
2245 source "security/Kconfig"
2247 source "crypto/Kconfig"
2249 source "arch/x86/kvm/Kconfig"
2251 source "lib/Kconfig"