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
15 select X86_DEV_DMA_OPS
20 select HAVE_AOUT if X86_32
21 select HAVE_UNSTABLE_SCHED_CLOCK
24 select HAVE_PCSPKR_PLATFORM
25 select HAVE_PERF_EVENTS
27 select HAVE_IOREMAP_PROT
30 select HAVE_MEMBLOCK_NODE_MAP
31 select ARCH_DISCARD_MEMBLOCK
32 select ARCH_WANT_OPTIONAL_GPIOLIB
33 select ARCH_WANT_FRAME_POINTERS
35 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
36 select HAVE_KRETPROBES
38 select HAVE_FTRACE_MCOUNT_RECORD
39 select HAVE_C_RECORDMCOUNT
40 select HAVE_DYNAMIC_FTRACE
41 select HAVE_FUNCTION_TRACER
42 select HAVE_FUNCTION_GRAPH_TRACER
43 select HAVE_FUNCTION_GRAPH_FP_TEST
44 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
45 select HAVE_SYSCALL_TRACEPOINTS
48 select HAVE_ARCH_TRACEHOOK
49 select HAVE_GENERIC_DMA_COHERENT if X86_32
50 select HAVE_EFFICIENT_UNALIGNED_ACCESS
51 select USER_STACKTRACE_SUPPORT
52 select HAVE_REGS_AND_STACK_ACCESS_API
53 select HAVE_DMA_API_DEBUG
54 select HAVE_KERNEL_GZIP
55 select HAVE_KERNEL_BZIP2
56 select HAVE_KERNEL_LZMA
58 select HAVE_KERNEL_LZO
59 select HAVE_HW_BREAKPOINT
60 select HAVE_MIXED_BREAKPOINTS_REGS
62 select HAVE_PERF_EVENTS_NMI
64 select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386
65 select HAVE_CMPXCHG_LOCAL if !M386
66 select HAVE_CMPXCHG_DOUBLE
67 select HAVE_ARCH_KMEMCHECK
68 select HAVE_USER_RETURN_NOTIFIER
69 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
70 select HAVE_ARCH_JUMP_LABEL
71 select HAVE_TEXT_POKE_SMP
72 select HAVE_GENERIC_HARDIRQS
74 select GENERIC_FIND_FIRST_BIT
75 select GENERIC_IRQ_PROBE
76 select GENERIC_PENDING_IRQ if SMP
77 select GENERIC_IRQ_SHOW
78 select GENERIC_CLOCKEVENTS_MIN_ADJUST
79 select IRQ_FORCED_THREADING
80 select USE_GENERIC_SMP_HELPERS if SMP
81 select HAVE_BPF_JIT if X86_64
83 select ARCH_HAVE_NMI_SAFE_CMPXCHG
85 select DCACHE_WORD_ACCESS
86 select GENERIC_SMP_IDLE_THREAD
87 select HAVE_ARCH_SECCOMP_FILTER
88 select BUILDTIME_EXTABLE_SORT
89 select GENERIC_CMOS_UPDATE
90 select CLOCKSOURCE_WATCHDOG
91 select GENERIC_CLOCKEVENTS
92 select ARCH_CLOCKSOURCE_DATA if X86_64
93 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
94 select GENERIC_TIME_VSYSCALL if X86_64
95 select KTIME_SCALAR if X86_32
97 config INSTRUCTION_DECODER
98 def_bool (KPROBES || PERF_EVENTS || UPROBES)
102 default "elf32-i386" if X86_32
103 default "elf64-x86-64" if X86_64
105 config ARCH_DEFCONFIG
107 default "arch/x86/configs/i386_defconfig" if X86_32
108 default "arch/x86/configs/x86_64_defconfig" if X86_64
110 config LOCKDEP_SUPPORT
113 config STACKTRACE_SUPPORT
116 config HAVE_LATENCYTOP_SUPPORT
125 config NEED_DMA_MAP_STATE
126 def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG)
128 config NEED_SG_DMA_LENGTH
131 config GENERIC_ISA_DMA
137 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
139 config GENERIC_BUG_RELATIVE_POINTERS
142 config GENERIC_HWEIGHT
148 config ARCH_MAY_HAVE_PC_FDC
151 config RWSEM_GENERIC_SPINLOCK
154 config RWSEM_XCHGADD_ALGORITHM
157 config GENERIC_CALIBRATE_DELAY
160 config ARCH_HAS_CPU_RELAX
163 config ARCH_HAS_DEFAULT_IDLE
166 config ARCH_HAS_CACHE_LINE_SIZE
169 config ARCH_HAS_CPU_AUTOPROBE
172 config HAVE_SETUP_PER_CPU_AREA
175 config NEED_PER_CPU_EMBED_FIRST_CHUNK
178 config NEED_PER_CPU_PAGE_FIRST_CHUNK
181 config ARCH_HIBERNATION_POSSIBLE
184 config ARCH_SUSPEND_POSSIBLE
195 config ARCH_SUPPORTS_OPTIMIZED_INLINING
198 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
201 config HAVE_INTEL_TXT
203 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
207 depends on X86_32 && SMP
211 depends on X86_64 && SMP
217 config X86_32_LAZY_GS
219 depends on X86_32 && !CC_STACKPROTECTOR
221 config ARCH_HWEIGHT_CFLAGS
223 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
224 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
226 config ARCH_CPU_PROBE_RELEASE
228 depends on HOTPLUG_CPU
230 config ARCH_SUPPORTS_UPROBES
233 source "init/Kconfig"
234 source "kernel/Kconfig.freezer"
236 menu "Processor type and features"
239 bool "DMA memory allocation support" if EXPERT
242 DMA memory allocation support allows devices with less than 32-bit
243 addressing to allocate within the first 16MB of address space.
244 Disable if no such devices will be used.
249 bool "Symmetric multi-processing support"
251 This enables support for systems with more than one CPU. If you have
252 a system with only one CPU, like most personal computers, say N. If
253 you have a system with more than one CPU, say Y.
255 If you say N here, the kernel will run on single and multiprocessor
256 machines, but will use only one CPU of a multiprocessor machine. If
257 you say Y here, the kernel will run on many, but not all,
258 singleprocessor machines. On a singleprocessor machine, the kernel
259 will run faster if you say N here.
261 Note that if you say Y here and choose architecture "586" or
262 "Pentium" under "Processor family", the kernel will not work on 486
263 architectures. Similarly, multiprocessor kernels for the "PPro"
264 architecture may not work on all Pentium based boards.
266 People using multiprocessor machines who say Y here should also say
267 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
268 Management" code will be disabled if you say Y here.
270 See also <file:Documentation/x86/i386/IO-APIC.txt>,
271 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
272 <http://www.tldp.org/docs.html#howto>.
274 If you don't know what to do here, say N.
277 bool "Support x2apic"
278 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
280 This enables x2apic support on CPUs that have this feature.
282 This allows 32-bit apic IDs (so it can support very large systems),
283 and accesses the local apic via MSRs not via mmio.
285 If you don't know what to do here, say N.
288 bool "Enable MPS table" if ACPI
290 depends on X86_LOCAL_APIC
292 For old smp systems that do not have proper acpi support. Newer systems
293 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
296 bool "Support for big SMP systems with more than 8 CPUs"
297 depends on X86_32 && SMP
299 This option is needed for the systems that have more than 8 CPUs
302 config X86_EXTENDED_PLATFORM
303 bool "Support for extended (non-PC) x86 platforms"
306 If you disable this option then the kernel will only support
307 standard PC platforms. (which covers the vast majority of
310 If you enable this option then you'll be able to select support
311 for the following (non-PC) 32 bit x86 platforms:
315 SGI 320/540 (Visual Workstation)
316 STA2X11-based (e.g. Northville)
317 Summit/EXA (IBM x440)
318 Unisys ES7000 IA32 series
319 Moorestown MID devices
321 If you have one of these systems, or if you want to build a
322 generic distribution kernel, say Y here - otherwise say N.
326 config X86_EXTENDED_PLATFORM
327 bool "Support for extended (non-PC) x86 platforms"
330 If you disable this option then the kernel will only support
331 standard PC platforms. (which covers the vast majority of
334 If you enable this option then you'll be able to select support
335 for the following (non-PC) 64 bit x86 platforms:
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.
343 # This is an alphabetically sorted list of 64 bit extended platforms
344 # Please maintain the alphabetic order if and when there are additions
346 bool "Numascale NumaChip"
348 depends on X86_EXTENDED_PLATFORM
351 depends on X86_X2APIC
353 Adds support for Numascale NumaChip large-SMP systems. Needed to
354 enable more than ~168 cores.
355 If you don't have one of these, you should say N here.
359 select PARAVIRT_GUEST
361 depends on X86_64 && PCI
362 depends on X86_EXTENDED_PLATFORM
365 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
366 supposed to run on these EM64T-based machines. Only choose this option
367 if you have one of these machines.
370 bool "SGI Ultraviolet"
372 depends on X86_EXTENDED_PLATFORM
374 depends on X86_X2APIC
376 This option is needed in order to support SGI Ultraviolet systems.
377 If you don't have one of these, you should say N here.
379 # Following is an alphabetically sorted list of 32 bit extended platforms
380 # Please maintain the alphabetic order if and when there are additions
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
393 Select for the Intel CE media processor (CE4100) SOC.
394 This option compiles in support for the CE4100 SOC for settop
395 boxes and media devices.
397 config X86_WANT_INTEL_MID
398 bool "Intel MID platform support"
400 depends on X86_EXTENDED_PLATFORM
402 Select to build a kernel capable of supporting Intel MID platform
403 systems which do not have the PCI legacy interfaces (Moorestown,
404 Medfield). If you are building for a PC class system say N here.
406 if X86_WANT_INTEL_MID
412 bool "Medfield MID platform"
415 depends on X86_IO_APIC
423 select X86_PLATFORM_DEVICES
424 select MFD_INTEL_MSIC
426 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
427 Internet Device(MID) platform.
428 Unlike standard x86 PCs, Medfield does not have many legacy devices
429 nor standard legacy replacement devices/features. e.g. Medfield does
430 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
435 bool "RDC R-321x SoC"
437 depends on X86_EXTENDED_PLATFORM
439 select X86_REBOOTFIXUPS
441 This option is needed for RDC R-321x system-on-chip, also known
443 If you don't have one of these chips, you should say N here.
445 config X86_32_NON_STANDARD
446 bool "Support non-standard 32-bit SMP architectures"
447 depends on X86_32 && SMP
448 depends on X86_EXTENDED_PLATFORM
450 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
451 STA2X11, default subarchitectures. It is intended for a generic
452 binary kernel. If you select them all, kernel will probe it
453 one by one and will fallback to default.
455 # Alphabetically sorted list of Non standard 32 bit platforms
458 bool "NUMAQ (IBM/Sequent)"
459 depends on X86_32_NON_STANDARD
464 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
465 NUMA multiquad box. This changes the way that processors are
466 bootstrapped, and uses Clustered Logical APIC addressing mode instead
467 of Flat Logical. You will need a new lynxer.elf file to flash your
468 firmware with - send email to <Martin.Bligh@us.ibm.com>.
470 config X86_SUPPORTS_MEMORY_FAILURE
472 # MCE code calls memory_failure():
474 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
475 depends on !X86_NUMAQ
476 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
477 depends on X86_64 || !SPARSEMEM
478 select ARCH_SUPPORTS_MEMORY_FAILURE
481 bool "SGI 320/540 (Visual Workstation)"
482 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
483 depends on X86_32_NON_STANDARD
485 The SGI Visual Workstation series is an IA32-based workstation
486 based on SGI systems chips with some legacy PC hardware attached.
488 Say Y here to create a kernel to run on the SGI 320 or 540.
490 A kernel compiled for the Visual Workstation will run on general
491 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
494 bool "STA2X11 Companion Chip Support"
495 depends on X86_32_NON_STANDARD && PCI
496 select X86_DEV_DMA_OPS
500 select ARCH_REQUIRE_GPIOLIB
503 This adds support for boards based on the STA2X11 IO-Hub,
504 a.k.a. "ConneXt". The chip is used in place of the standard
505 PC chipset, so all "standard" peripherals are missing. If this
506 option is selected the kernel will still be able to boot on
507 standard PC machines.
510 bool "Summit/EXA (IBM x440)"
511 depends on X86_32_NON_STANDARD
513 This option is needed for IBM systems that use the Summit/EXA chipset.
514 In particular, it is needed for the x440.
517 bool "Unisys ES7000 IA32 series"
518 depends on X86_32_NON_STANDARD && X86_BIGSMP
520 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
521 supposed to run on an IA32-based Unisys ES7000 system.
524 tristate "Eurobraille/Iris poweroff module"
527 The Iris machines from EuroBraille do not have APM or ACPI support
528 to shut themselves down properly. A special I/O sequence is
529 needed to do so, which is what this module does at
532 This is only for Iris machines from EuroBraille.
536 config SCHED_OMIT_FRAME_POINTER
538 prompt "Single-depth WCHAN output"
541 Calculate simpler /proc/<PID>/wchan values. If this option
542 is disabled then wchan values will recurse back to the
543 caller function. This provides more accurate wchan values,
544 at the expense of slightly more scheduling overhead.
546 If in doubt, say "Y".
548 menuconfig PARAVIRT_GUEST
549 bool "Paravirtualized guest support"
551 Say Y here to get to see options related to running Linux under
552 various hypervisors. This option alone does not add any kernel code.
554 If you say N, all options in this submenu will be skipped and disabled.
558 config PARAVIRT_TIME_ACCOUNTING
559 bool "Paravirtual steal time accounting"
563 Select this option to enable fine granularity task steal time
564 accounting. Time spent executing other tasks in parallel with
565 the current vCPU is discounted from the vCPU power. To account for
566 that, there can be a small performance impact.
568 If in doubt, say N here.
570 source "arch/x86/xen/Kconfig"
573 bool "KVM paravirtualized clock"
575 select PARAVIRT_CLOCK
577 Turning on this option will allow you to run a paravirtualized clock
578 when running over the KVM hypervisor. Instead of relying on a PIT
579 (or probably other) emulation by the underlying device model, the host
580 provides the guest with timing infrastructure such as time of day, and
584 bool "KVM Guest support"
587 This option enables various optimizations for running under the KVM
590 source "arch/x86/lguest/Kconfig"
593 bool "Enable paravirtualization code"
595 This changes the kernel so it can modify itself when it is run
596 under a hypervisor, potentially improving performance significantly
597 over full virtualization. However, when run without a hypervisor
598 the kernel is theoretically slower and slightly larger.
600 config PARAVIRT_SPINLOCKS
601 bool "Paravirtualization layer for spinlocks"
602 depends on PARAVIRT && SMP && EXPERIMENTAL
604 Paravirtualized spinlocks allow a pvops backend to replace the
605 spinlock implementation with something virtualization-friendly
606 (for example, block the virtual CPU rather than spinning).
608 Unfortunately the downside is an up to 5% performance hit on
609 native kernels, with various workloads.
611 If you are unsure how to answer this question, answer N.
613 config PARAVIRT_CLOCK
618 config PARAVIRT_DEBUG
619 bool "paravirt-ops debugging"
620 depends on PARAVIRT && DEBUG_KERNEL
622 Enable to debug paravirt_ops internals. Specifically, BUG if
623 a paravirt_op is missing when it is called.
631 This option adds a kernel parameter 'memtest', which allows memtest
633 memtest=0, mean disabled; -- default
634 memtest=1, mean do 1 test pattern;
636 memtest=4, mean do 4 test patterns.
637 If you are unsure how to answer this question, answer N.
639 config X86_SUMMIT_NUMA
641 depends on X86_32 && NUMA && X86_32_NON_STANDARD
643 config X86_CYCLONE_TIMER
645 depends on X86_SUMMIT
647 source "arch/x86/Kconfig.cpu"
651 prompt "HPET Timer Support" if X86_32
653 Use the IA-PC HPET (High Precision Event Timer) to manage
654 time in preference to the PIT and RTC, if a HPET is
656 HPET is the next generation timer replacing legacy 8254s.
657 The HPET provides a stable time base on SMP
658 systems, unlike the TSC, but it is more expensive to access,
659 as it is off-chip. You can find the HPET spec at
660 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
662 You can safely choose Y here. However, HPET will only be
663 activated if the platform and the BIOS support this feature.
664 Otherwise the 8254 will be used for timing services.
666 Choose N to continue using the legacy 8254 timer.
668 config HPET_EMULATE_RTC
670 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
673 def_bool y if X86_INTEL_MID
674 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
676 depends on X86_INTEL_MID && SFI
678 APB timer is the replacement for 8254, HPET on X86 MID platforms.
679 The APBT provides a stable time base on SMP
680 systems, unlike the TSC, but it is more expensive to access,
681 as it is off-chip. APB timers are always running regardless of CPU
682 C states, they are used as per CPU clockevent device when possible.
684 # Mark as expert because too many people got it wrong.
685 # The code disables itself when not needed.
688 bool "Enable DMI scanning" if EXPERT
690 Enabled scanning of DMI to identify machine quirks. Say Y
691 here unless you have verified that your setup is not
692 affected by entries in the DMI blacklist. Required by PNP
696 bool "GART IOMMU support" if EXPERT
699 depends on X86_64 && PCI && AMD_NB
701 Support for full DMA access of devices with 32bit memory access only
702 on systems with more than 3GB. This is usually needed for USB,
703 sound, many IDE/SATA chipsets and some other devices.
704 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
705 based hardware IOMMU and a software bounce buffer based IOMMU used
706 on Intel systems and as fallback.
707 The code is only active when needed (enough memory and limited
708 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
712 bool "IBM Calgary IOMMU support"
714 depends on X86_64 && PCI && EXPERIMENTAL
716 Support for hardware IOMMUs in IBM's xSeries x366 and x460
717 systems. Needed to run systems with more than 3GB of memory
718 properly with 32-bit PCI devices that do not support DAC
719 (Double Address Cycle). Calgary also supports bus level
720 isolation, where all DMAs pass through the IOMMU. This
721 prevents them from going anywhere except their intended
722 destination. This catches hard-to-find kernel bugs and
723 mis-behaving drivers and devices that do not use the DMA-API
724 properly to set up their DMA buffers. The IOMMU can be
725 turned off at boot time with the iommu=off parameter.
726 Normally the kernel will make the right choice by itself.
729 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
731 prompt "Should Calgary be enabled by default?"
732 depends on CALGARY_IOMMU
734 Should Calgary be enabled by default? if you choose 'y', Calgary
735 will be used (if it exists). If you choose 'n', Calgary will not be
736 used even if it exists. If you choose 'n' and would like to use
737 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
740 # need this always selected by IOMMU for the VIA workaround
744 Support for software bounce buffers used on x86-64 systems
745 which don't have a hardware IOMMU (e.g. the current generation
746 of Intel's x86-64 CPUs). Using this PCI devices which can only
747 access 32-bits of memory can be used on systems with more than
748 3 GB of memory. If unsure, say Y.
751 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
754 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
755 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
756 select CPUMASK_OFFSTACK
758 Enable maximum number of CPUS and NUMA Nodes for this architecture.
762 int "Maximum number of CPUs" if SMP && !MAXSMP
763 range 2 8 if SMP && X86_32 && !X86_BIGSMP
764 range 2 512 if SMP && !MAXSMP
766 default "4096" if MAXSMP
767 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
770 This allows you to specify the maximum number of CPUs which this
771 kernel will support. The maximum supported value is 512 and the
772 minimum value which makes sense is 2.
774 This is purely to save memory - each supported CPU adds
775 approximately eight kilobytes to the kernel image.
778 bool "SMT (Hyperthreading) scheduler support"
781 SMT scheduler support improves the CPU scheduler's decision making
782 when dealing with Intel Pentium 4 chips with HyperThreading at a
783 cost of slightly increased overhead in some places. If unsure say
788 prompt "Multi-core scheduler support"
791 Multi-core scheduler support improves the CPU scheduler's decision
792 making when dealing with multi-core CPU chips at a cost of slightly
793 increased overhead in some places. If unsure say N here.
795 config IRQ_TIME_ACCOUNTING
796 bool "Fine granularity task level IRQ time accounting"
799 Select this option to enable fine granularity task irq time
800 accounting. This is done by reading a timestamp on each
801 transitions between softirq and hardirq state, so there can be a
802 small performance impact.
804 If in doubt, say N here.
806 source "kernel/Kconfig.preempt"
809 bool "Local APIC support on uniprocessors"
810 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
812 A local APIC (Advanced Programmable Interrupt Controller) is an
813 integrated interrupt controller in the CPU. If you have a single-CPU
814 system which has a processor with a local APIC, you can say Y here to
815 enable and use it. If you say Y here even though your machine doesn't
816 have a local APIC, then the kernel will still run with no slowdown at
817 all. The local APIC supports CPU-generated self-interrupts (timer,
818 performance counters), and the NMI watchdog which detects hard
822 bool "IO-APIC support on uniprocessors"
823 depends on X86_UP_APIC
825 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
826 SMP-capable replacement for PC-style interrupt controllers. Most
827 SMP systems and many recent uniprocessor systems have one.
829 If you have a single-CPU system with an IO-APIC, you can say Y here
830 to use it. If you say Y here even though your machine doesn't have
831 an IO-APIC, then the kernel will still run with no slowdown at all.
833 config X86_LOCAL_APIC
835 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
839 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
841 config X86_VISWS_APIC
843 depends on X86_32 && X86_VISWS
845 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
846 bool "Reroute for broken boot IRQs"
847 depends on X86_IO_APIC
849 This option enables a workaround that fixes a source of
850 spurious interrupts. This is recommended when threaded
851 interrupt handling is used on systems where the generation of
852 superfluous "boot interrupts" cannot be disabled.
854 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
855 entry in the chipset's IO-APIC is masked (as, e.g. the RT
856 kernel does during interrupt handling). On chipsets where this
857 boot IRQ generation cannot be disabled, this workaround keeps
858 the original IRQ line masked so that only the equivalent "boot
859 IRQ" is delivered to the CPUs. The workaround also tells the
860 kernel to set up the IRQ handler on the boot IRQ line. In this
861 way only one interrupt is delivered to the kernel. Otherwise
862 the spurious second interrupt may cause the kernel to bring
863 down (vital) interrupt lines.
865 Only affects "broken" chipsets. Interrupt sharing may be
866 increased on these systems.
869 bool "Machine Check / overheating reporting"
871 Machine Check support allows the processor to notify the
872 kernel if it detects a problem (e.g. overheating, data corruption).
873 The action the kernel takes depends on the severity of the problem,
874 ranging from warning messages to halting the machine.
878 prompt "Intel MCE features"
879 depends on X86_MCE && X86_LOCAL_APIC
881 Additional support for intel specific MCE features such as
886 prompt "AMD MCE features"
887 depends on X86_MCE && X86_LOCAL_APIC
889 Additional support for AMD specific MCE features such as
890 the DRAM Error Threshold.
892 config X86_ANCIENT_MCE
893 bool "Support for old Pentium 5 / WinChip machine checks"
894 depends on X86_32 && X86_MCE
896 Include support for machine check handling on old Pentium 5 or WinChip
897 systems. These typically need to be enabled explicitely on the command
900 config X86_MCE_THRESHOLD
901 depends on X86_MCE_AMD || X86_MCE_INTEL
904 config X86_MCE_INJECT
906 tristate "Machine check injector support"
908 Provide support for injecting machine checks for testing purposes.
909 If you don't know what a machine check is and you don't do kernel
910 QA it is safe to say n.
912 config X86_THERMAL_VECTOR
914 depends on X86_MCE_INTEL
917 bool "Enable VM86 support" if EXPERT
921 This option is required by programs like DOSEMU to run 16-bit legacy
922 code on X86 processors. It also may be needed by software like
923 XFree86 to initialize some video cards via BIOS. Disabling this
924 option saves about 6k.
927 tristate "Toshiba Laptop support"
930 This adds a driver to safely access the System Management Mode of
931 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
932 not work on models with a Phoenix BIOS. The System Management Mode
933 is used to set the BIOS and power saving options on Toshiba portables.
935 For information on utilities to make use of this driver see the
936 Toshiba Linux utilities web site at:
937 <http://www.buzzard.org.uk/toshiba/>.
939 Say Y if you intend to run this kernel on a Toshiba portable.
943 tristate "Dell laptop support"
946 This adds a driver to safely access the System Management Mode
947 of the CPU on the Dell Inspiron 8000. The System Management Mode
948 is used to read cpu temperature and cooling fan status and to
949 control the fans on the I8K portables.
951 This driver has been tested only on the Inspiron 8000 but it may
952 also work with other Dell laptops. You can force loading on other
953 models by passing the parameter `force=1' to the module. Use at
956 For information on utilities to make use of this driver see the
957 I8K Linux utilities web site at:
958 <http://people.debian.org/~dz/i8k/>
960 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
963 config X86_REBOOTFIXUPS
964 bool "Enable X86 board specific fixups for reboot"
967 This enables chipset and/or board specific fixups to be done
968 in order to get reboot to work correctly. This is only needed on
969 some combinations of hardware and BIOS. The symptom, for which
970 this config is intended, is when reboot ends with a stalled/hung
973 Currently, the only fixup is for the Geode machines using
974 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
976 Say Y if you want to enable the fixup. Currently, it's safe to
977 enable this option even if you don't need it.
981 tristate "/dev/cpu/microcode - microcode support"
984 If you say Y here, you will be able to update the microcode on
985 certain Intel and AMD processors. The Intel support is for the
986 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
987 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
988 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
989 You will obviously need the actual microcode binary data itself
990 which is not shipped with the Linux kernel.
992 This option selects the general module only, you need to select
993 at least one vendor specific module as well.
995 To compile this driver as a module, choose M here: the
996 module will be called microcode.
998 config MICROCODE_INTEL
999 bool "Intel microcode patch loading support"
1000 depends on MICROCODE
1004 This options enables microcode patch loading support for Intel
1007 For latest news and information on obtaining all the required
1008 Intel ingredients for this driver, check:
1009 <http://www.urbanmyth.org/microcode/>.
1011 config MICROCODE_AMD
1012 bool "AMD microcode patch loading support"
1013 depends on MICROCODE
1016 If you select this option, microcode patch loading support for AMD
1017 processors will be enabled.
1019 config MICROCODE_OLD_INTERFACE
1021 depends on MICROCODE
1024 tristate "/dev/cpu/*/msr - Model-specific register support"
1026 This device gives privileged processes access to the x86
1027 Model-Specific Registers (MSRs). It is a character device with
1028 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1029 MSR accesses are directed to a specific CPU on multi-processor
1033 tristate "/dev/cpu/*/cpuid - CPU information support"
1035 This device gives processes access to the x86 CPUID instruction to
1036 be executed on a specific processor. It is a character device
1037 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1041 prompt "High Memory Support"
1042 default HIGHMEM64G if X86_NUMAQ
1048 depends on !X86_NUMAQ
1050 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1051 However, the address space of 32-bit x86 processors is only 4
1052 Gigabytes large. That means that, if you have a large amount of
1053 physical memory, not all of it can be "permanently mapped" by the
1054 kernel. The physical memory that's not permanently mapped is called
1057 If you are compiling a kernel which will never run on a machine with
1058 more than 1 Gigabyte total physical RAM, answer "off" here (default
1059 choice and suitable for most users). This will result in a "3GB/1GB"
1060 split: 3GB are mapped so that each process sees a 3GB virtual memory
1061 space and the remaining part of the 4GB virtual memory space is used
1062 by the kernel to permanently map as much physical memory as
1065 If the machine has between 1 and 4 Gigabytes physical RAM, then
1068 If more than 4 Gigabytes is used then answer "64GB" here. This
1069 selection turns Intel PAE (Physical Address Extension) mode on.
1070 PAE implements 3-level paging on IA32 processors. PAE is fully
1071 supported by Linux, PAE mode is implemented on all recent Intel
1072 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1073 then the kernel will not boot on CPUs that don't support PAE!
1075 The actual amount of total physical memory will either be
1076 auto detected or can be forced by using a kernel command line option
1077 such as "mem=256M". (Try "man bootparam" or see the documentation of
1078 your boot loader (lilo or loadlin) about how to pass options to the
1079 kernel at boot time.)
1081 If unsure, say "off".
1085 depends on !X86_NUMAQ
1087 Select this if you have a 32-bit processor and between 1 and 4
1088 gigabytes of physical RAM.
1092 depends on !M386 && !M486
1095 Select this if you have a 32-bit processor and more than 4
1096 gigabytes of physical RAM.
1101 depends on EXPERIMENTAL
1102 prompt "Memory split" if EXPERT
1106 Select the desired split between kernel and user memory.
1108 If the address range available to the kernel is less than the
1109 physical memory installed, the remaining memory will be available
1110 as "high memory". Accessing high memory is a little more costly
1111 than low memory, as it needs to be mapped into the kernel first.
1112 Note that increasing the kernel address space limits the range
1113 available to user programs, making the address space there
1114 tighter. Selecting anything other than the default 3G/1G split
1115 will also likely make your kernel incompatible with binary-only
1118 If you are not absolutely sure what you are doing, leave this
1122 bool "3G/1G user/kernel split"
1123 config VMSPLIT_3G_OPT
1125 bool "3G/1G user/kernel split (for full 1G low memory)"
1127 bool "2G/2G user/kernel split"
1128 config VMSPLIT_2G_OPT
1130 bool "2G/2G user/kernel split (for full 2G low memory)"
1132 bool "1G/3G user/kernel split"
1137 default 0xB0000000 if VMSPLIT_3G_OPT
1138 default 0x80000000 if VMSPLIT_2G
1139 default 0x78000000 if VMSPLIT_2G_OPT
1140 default 0x40000000 if VMSPLIT_1G
1146 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1149 bool "PAE (Physical Address Extension) Support"
1150 depends on X86_32 && !HIGHMEM4G
1152 PAE is required for NX support, and furthermore enables
1153 larger swapspace support for non-overcommit purposes. It
1154 has the cost of more pagetable lookup overhead, and also
1155 consumes more pagetable space per process.
1157 config ARCH_PHYS_ADDR_T_64BIT
1158 def_bool X86_64 || X86_PAE
1160 config ARCH_DMA_ADDR_T_64BIT
1161 def_bool X86_64 || HIGHMEM64G
1163 config DIRECT_GBPAGES
1164 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1168 Allow the kernel linear mapping to use 1GB pages on CPUs that
1169 support it. This can improve the kernel's performance a tiny bit by
1170 reducing TLB pressure. If in doubt, say "Y".
1172 # Common NUMA Features
1174 bool "Numa Memory Allocation and Scheduler Support"
1176 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1177 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1179 Enable NUMA (Non Uniform Memory Access) support.
1181 The kernel will try to allocate memory used by a CPU on the
1182 local memory controller of the CPU and add some more
1183 NUMA awareness to the kernel.
1185 For 64-bit this is recommended if the system is Intel Core i7
1186 (or later), AMD Opteron, or EM64T NUMA.
1188 For 32-bit this is only needed on (rare) 32-bit-only platforms
1189 that support NUMA topologies, such as NUMAQ / Summit, or if you
1190 boot a 32-bit kernel on a 64-bit NUMA platform.
1192 Otherwise, you should say N.
1194 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1195 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1199 prompt "Old style AMD Opteron NUMA detection"
1200 depends on X86_64 && NUMA && PCI
1202 Enable AMD NUMA node topology detection. You should say Y here if
1203 you have a multi processor AMD system. This uses an old method to
1204 read the NUMA configuration directly from the builtin Northbridge
1205 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1206 which also takes priority if both are compiled in.
1208 config X86_64_ACPI_NUMA
1210 prompt "ACPI NUMA detection"
1211 depends on X86_64 && NUMA && ACPI && PCI
1214 Enable ACPI SRAT based node topology detection.
1216 # Some NUMA nodes have memory ranges that span
1217 # other nodes. Even though a pfn is valid and
1218 # between a node's start and end pfns, it may not
1219 # reside on that node. See memmap_init_zone()
1221 config NODES_SPAN_OTHER_NODES
1223 depends on X86_64_ACPI_NUMA
1226 bool "NUMA emulation"
1229 Enable NUMA emulation. A flat machine will be split
1230 into virtual nodes when booted with "numa=fake=N", where N is the
1231 number of nodes. This is only useful for debugging.
1234 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1236 default "10" if MAXSMP
1237 default "6" if X86_64
1238 default "4" if X86_NUMAQ
1240 depends on NEED_MULTIPLE_NODES
1242 Specify the maximum number of NUMA Nodes available on the target
1243 system. Increases memory reserved to accommodate various tables.
1245 config HAVE_ARCH_ALLOC_REMAP
1247 depends on X86_32 && NUMA
1249 config ARCH_HAVE_MEMORY_PRESENT
1251 depends on X86_32 && DISCONTIGMEM
1253 config NEED_NODE_MEMMAP_SIZE
1255 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1257 config ARCH_FLATMEM_ENABLE
1259 depends on X86_32 && !NUMA
1261 config ARCH_DISCONTIGMEM_ENABLE
1263 depends on NUMA && X86_32
1265 config ARCH_DISCONTIGMEM_DEFAULT
1267 depends on NUMA && X86_32
1269 config ARCH_SPARSEMEM_ENABLE
1271 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1272 select SPARSEMEM_STATIC if X86_32
1273 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1275 config ARCH_SPARSEMEM_DEFAULT
1279 config ARCH_SELECT_MEMORY_MODEL
1281 depends on ARCH_SPARSEMEM_ENABLE
1283 config ARCH_MEMORY_PROBE
1285 depends on MEMORY_HOTPLUG
1287 config ARCH_PROC_KCORE_TEXT
1289 depends on X86_64 && PROC_KCORE
1291 config ILLEGAL_POINTER_VALUE
1294 default 0xdead000000000000 if X86_64
1299 bool "Allocate 3rd-level pagetables from highmem"
1302 The VM uses one page table entry for each page of physical memory.
1303 For systems with a lot of RAM, this can be wasteful of precious
1304 low memory. Setting this option will put user-space page table
1305 entries in high memory.
1307 config X86_CHECK_BIOS_CORRUPTION
1308 bool "Check for low memory corruption"
1310 Periodically check for memory corruption in low memory, which
1311 is suspected to be caused by BIOS. Even when enabled in the
1312 configuration, it is disabled at runtime. Enable it by
1313 setting "memory_corruption_check=1" on the kernel command
1314 line. By default it scans the low 64k of memory every 60
1315 seconds; see the memory_corruption_check_size and
1316 memory_corruption_check_period parameters in
1317 Documentation/kernel-parameters.txt to adjust this.
1319 When enabled with the default parameters, this option has
1320 almost no overhead, as it reserves a relatively small amount
1321 of memory and scans it infrequently. It both detects corruption
1322 and prevents it from affecting the running system.
1324 It is, however, intended as a diagnostic tool; if repeatable
1325 BIOS-originated corruption always affects the same memory,
1326 you can use memmap= to prevent the kernel from using that
1329 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1330 bool "Set the default setting of memory_corruption_check"
1331 depends on X86_CHECK_BIOS_CORRUPTION
1334 Set whether the default state of memory_corruption_check is
1337 config X86_RESERVE_LOW
1338 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1342 Specify the amount of low memory to reserve for the BIOS.
1344 The first page contains BIOS data structures that the kernel
1345 must not use, so that page must always be reserved.
1347 By default we reserve the first 64K of physical RAM, as a
1348 number of BIOSes are known to corrupt that memory range
1349 during events such as suspend/resume or monitor cable
1350 insertion, so it must not be used by the kernel.
1352 You can set this to 4 if you are absolutely sure that you
1353 trust the BIOS to get all its memory reservations and usages
1354 right. If you know your BIOS have problems beyond the
1355 default 64K area, you can set this to 640 to avoid using the
1356 entire low memory range.
1358 If you have doubts about the BIOS (e.g. suspend/resume does
1359 not work or there's kernel crashes after certain hardware
1360 hotplug events) then you might want to enable
1361 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1362 typical corruption patterns.
1364 Leave this to the default value of 64 if you are unsure.
1366 config MATH_EMULATION
1368 prompt "Math emulation" if X86_32
1370 Linux can emulate a math coprocessor (used for floating point
1371 operations) if you don't have one. 486DX and Pentium processors have
1372 a math coprocessor built in, 486SX and 386 do not, unless you added
1373 a 487DX or 387, respectively. (The messages during boot time can
1374 give you some hints here ["man dmesg"].) Everyone needs either a
1375 coprocessor or this emulation.
1377 If you don't have a math coprocessor, you need to say Y here; if you
1378 say Y here even though you have a coprocessor, the coprocessor will
1379 be used nevertheless. (This behavior can be changed with the kernel
1380 command line option "no387", which comes handy if your coprocessor
1381 is broken. Try "man bootparam" or see the documentation of your boot
1382 loader (lilo or loadlin) about how to pass options to the kernel at
1383 boot time.) This means that it is a good idea to say Y here if you
1384 intend to use this kernel on different machines.
1386 More information about the internals of the Linux math coprocessor
1387 emulation can be found in <file:arch/x86/math-emu/README>.
1389 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1390 kernel, it won't hurt.
1394 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1396 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1397 the Memory Type Range Registers (MTRRs) may be used to control
1398 processor access to memory ranges. This is most useful if you have
1399 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1400 allows bus write transfers to be combined into a larger transfer
1401 before bursting over the PCI/AGP bus. This can increase performance
1402 of image write operations 2.5 times or more. Saying Y here creates a
1403 /proc/mtrr file which may be used to manipulate your processor's
1404 MTRRs. Typically the X server should use this.
1406 This code has a reasonably generic interface so that similar
1407 control registers on other processors can be easily supported
1410 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1411 Registers (ARRs) which provide a similar functionality to MTRRs. For
1412 these, the ARRs are used to emulate the MTRRs.
1413 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1414 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1415 write-combining. All of these processors are supported by this code
1416 and it makes sense to say Y here if you have one of them.
1418 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1419 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1420 can lead to all sorts of problems, so it's good to say Y here.
1422 You can safely say Y even if your machine doesn't have MTRRs, you'll
1423 just add about 9 KB to your kernel.
1425 See <file:Documentation/x86/mtrr.txt> for more information.
1427 config MTRR_SANITIZER
1429 prompt "MTRR cleanup support"
1432 Convert MTRR layout from continuous to discrete, so X drivers can
1433 add writeback entries.
1435 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1436 The largest mtrr entry size for a continuous block can be set with
1441 config MTRR_SANITIZER_ENABLE_DEFAULT
1442 int "MTRR cleanup enable value (0-1)"
1445 depends on MTRR_SANITIZER
1447 Enable mtrr cleanup default value
1449 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1450 int "MTRR cleanup spare reg num (0-7)"
1453 depends on MTRR_SANITIZER
1455 mtrr cleanup spare entries default, it can be changed via
1456 mtrr_spare_reg_nr=N on the kernel command line.
1460 prompt "x86 PAT support" if EXPERT
1463 Use PAT attributes to setup page level cache control.
1465 PATs are the modern equivalents of MTRRs and are much more
1466 flexible than MTRRs.
1468 Say N here if you see bootup problems (boot crash, boot hang,
1469 spontaneous reboots) or a non-working video driver.
1473 config ARCH_USES_PG_UNCACHED
1479 prompt "x86 architectural random number generator" if EXPERT
1481 Enable the x86 architectural RDRAND instruction
1482 (Intel Bull Mountain technology) to generate random numbers.
1483 If supported, this is a high bandwidth, cryptographically
1484 secure hardware random number generator.
1487 bool "EFI runtime service support"
1490 This enables the kernel to use EFI runtime services that are
1491 available (such as the EFI variable services).
1493 This option is only useful on systems that have EFI firmware.
1494 In addition, you should use the latest ELILO loader available
1495 at <http://elilo.sourceforge.net> in order to take advantage
1496 of EFI runtime services. However, even with this option, the
1497 resultant kernel should continue to boot on existing non-EFI
1501 bool "EFI stub support"
1504 This kernel feature allows a bzImage to be loaded directly
1505 by EFI firmware without the use of a bootloader.
1509 prompt "Enable seccomp to safely compute untrusted bytecode"
1511 This kernel feature is useful for number crunching applications
1512 that may need to compute untrusted bytecode during their
1513 execution. By using pipes or other transports made available to
1514 the process as file descriptors supporting the read/write
1515 syscalls, it's possible to isolate those applications in
1516 their own address space using seccomp. Once seccomp is
1517 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1518 and the task is only allowed to execute a few safe syscalls
1519 defined by each seccomp mode.
1521 If unsure, say Y. Only embedded should say N here.
1523 config CC_STACKPROTECTOR
1524 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1526 This option turns on the -fstack-protector GCC feature. This
1527 feature puts, at the beginning of functions, a canary value on
1528 the stack just before the return address, and validates
1529 the value just before actually returning. Stack based buffer
1530 overflows (that need to overwrite this return address) now also
1531 overwrite the canary, which gets detected and the attack is then
1532 neutralized via a kernel panic.
1534 This feature requires gcc version 4.2 or above, or a distribution
1535 gcc with the feature backported. Older versions are automatically
1536 detected and for those versions, this configuration option is
1537 ignored. (and a warning is printed during bootup)
1539 source kernel/Kconfig.hz
1542 bool "kexec system call"
1544 kexec is a system call that implements the ability to shutdown your
1545 current kernel, and to start another kernel. It is like a reboot
1546 but it is independent of the system firmware. And like a reboot
1547 you can start any kernel with it, not just Linux.
1549 The name comes from the similarity to the exec system call.
1551 It is an ongoing process to be certain the hardware in a machine
1552 is properly shutdown, so do not be surprised if this code does not
1553 initially work for you. It may help to enable device hotplugging
1554 support. As of this writing the exact hardware interface is
1555 strongly in flux, so no good recommendation can be made.
1558 bool "kernel crash dumps"
1559 depends on X86_64 || (X86_32 && HIGHMEM)
1561 Generate crash dump after being started by kexec.
1562 This should be normally only set in special crash dump kernels
1563 which are loaded in the main kernel with kexec-tools into
1564 a specially reserved region and then later executed after
1565 a crash by kdump/kexec. The crash dump kernel must be compiled
1566 to a memory address not used by the main kernel or BIOS using
1567 PHYSICAL_START, or it must be built as a relocatable image
1568 (CONFIG_RELOCATABLE=y).
1569 For more details see Documentation/kdump/kdump.txt
1572 bool "kexec jump (EXPERIMENTAL)"
1573 depends on EXPERIMENTAL
1574 depends on KEXEC && HIBERNATION
1576 Jump between original kernel and kexeced kernel and invoke
1577 code in physical address mode via KEXEC
1579 config PHYSICAL_START
1580 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1583 This gives the physical address where the kernel is loaded.
1585 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1586 bzImage will decompress itself to above physical address and
1587 run from there. Otherwise, bzImage will run from the address where
1588 it has been loaded by the boot loader and will ignore above physical
1591 In normal kdump cases one does not have to set/change this option
1592 as now bzImage can be compiled as a completely relocatable image
1593 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1594 address. This option is mainly useful for the folks who don't want
1595 to use a bzImage for capturing the crash dump and want to use a
1596 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1597 to be specifically compiled to run from a specific memory area
1598 (normally a reserved region) and this option comes handy.
1600 So if you are using bzImage for capturing the crash dump,
1601 leave the value here unchanged to 0x1000000 and set
1602 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1603 for capturing the crash dump change this value to start of
1604 the reserved region. In other words, it can be set based on
1605 the "X" value as specified in the "crashkernel=YM@XM"
1606 command line boot parameter passed to the panic-ed
1607 kernel. Please take a look at Documentation/kdump/kdump.txt
1608 for more details about crash dumps.
1610 Usage of bzImage for capturing the crash dump is recommended as
1611 one does not have to build two kernels. Same kernel can be used
1612 as production kernel and capture kernel. Above option should have
1613 gone away after relocatable bzImage support is introduced. But it
1614 is present because there are users out there who continue to use
1615 vmlinux for dump capture. This option should go away down the
1618 Don't change this unless you know what you are doing.
1621 bool "Build a relocatable kernel"
1624 This builds a kernel image that retains relocation information
1625 so it can be loaded someplace besides the default 1MB.
1626 The relocations tend to make the kernel binary about 10% larger,
1627 but are discarded at runtime.
1629 One use is for the kexec on panic case where the recovery kernel
1630 must live at a different physical address than the primary
1633 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1634 it has been loaded at and the compile time physical address
1635 (CONFIG_PHYSICAL_START) is ignored.
1637 # Relocation on x86-32 needs some additional build support
1638 config X86_NEED_RELOCS
1640 depends on X86_32 && RELOCATABLE
1642 config PHYSICAL_ALIGN
1643 hex "Alignment value to which kernel should be aligned" if X86_32
1645 range 0x2000 0x1000000
1647 This value puts the alignment restrictions on physical address
1648 where kernel is loaded and run from. Kernel is compiled for an
1649 address which meets above alignment restriction.
1651 If bootloader loads the kernel at a non-aligned address and
1652 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1653 address aligned to above value and run from there.
1655 If bootloader loads the kernel at a non-aligned address and
1656 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1657 load address and decompress itself to the address it has been
1658 compiled for and run from there. The address for which kernel is
1659 compiled already meets above alignment restrictions. Hence the
1660 end result is that kernel runs from a physical address meeting
1661 above alignment restrictions.
1663 Don't change this unless you know what you are doing.
1666 bool "Support for hot-pluggable CPUs"
1667 depends on SMP && HOTPLUG
1669 Say Y here to allow turning CPUs off and on. CPUs can be
1670 controlled through /sys/devices/system/cpu.
1671 ( Note: power management support will enable this option
1672 automatically on SMP systems. )
1673 Say N if you want to disable CPU hotplug.
1677 prompt "Compat VDSO support"
1678 depends on X86_32 || IA32_EMULATION
1680 Map the 32-bit VDSO to the predictable old-style address too.
1682 Say N here if you are running a sufficiently recent glibc
1683 version (2.3.3 or later), to remove the high-mapped
1684 VDSO mapping and to exclusively use the randomized VDSO.
1689 bool "Built-in kernel command line"
1691 Allow for specifying boot arguments to the kernel at
1692 build time. On some systems (e.g. embedded ones), it is
1693 necessary or convenient to provide some or all of the
1694 kernel boot arguments with the kernel itself (that is,
1695 to not rely on the boot loader to provide them.)
1697 To compile command line arguments into the kernel,
1698 set this option to 'Y', then fill in the
1699 the boot arguments in CONFIG_CMDLINE.
1701 Systems with fully functional boot loaders (i.e. non-embedded)
1702 should leave this option set to 'N'.
1705 string "Built-in kernel command string"
1706 depends on CMDLINE_BOOL
1709 Enter arguments here that should be compiled into the kernel
1710 image and used at boot time. If the boot loader provides a
1711 command line at boot time, it is appended to this string to
1712 form the full kernel command line, when the system boots.
1714 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1715 change this behavior.
1717 In most cases, the command line (whether built-in or provided
1718 by the boot loader) should specify the device for the root
1721 config CMDLINE_OVERRIDE
1722 bool "Built-in command line overrides boot loader arguments"
1723 depends on CMDLINE_BOOL
1725 Set this option to 'Y' to have the kernel ignore the boot loader
1726 command line, and use ONLY the built-in command line.
1728 This is used to work around broken boot loaders. This should
1729 be set to 'N' under normal conditions.
1733 config ARCH_ENABLE_MEMORY_HOTPLUG
1735 depends on X86_64 || (X86_32 && HIGHMEM)
1737 config ARCH_ENABLE_MEMORY_HOTREMOVE
1739 depends on MEMORY_HOTPLUG
1741 config USE_PERCPU_NUMA_NODE_ID
1745 menu "Power management and ACPI options"
1747 config ARCH_HIBERNATION_HEADER
1749 depends on X86_64 && HIBERNATION
1751 source "kernel/power/Kconfig"
1753 source "drivers/acpi/Kconfig"
1755 source "drivers/sfi/Kconfig"
1762 tristate "APM (Advanced Power Management) BIOS support"
1763 depends on X86_32 && PM_SLEEP
1765 APM is a BIOS specification for saving power using several different
1766 techniques. This is mostly useful for battery powered laptops with
1767 APM compliant BIOSes. If you say Y here, the system time will be
1768 reset after a RESUME operation, the /proc/apm device will provide
1769 battery status information, and user-space programs will receive
1770 notification of APM "events" (e.g. battery status change).
1772 If you select "Y" here, you can disable actual use of the APM
1773 BIOS by passing the "apm=off" option to the kernel at boot time.
1775 Note that the APM support is almost completely disabled for
1776 machines with more than one CPU.
1778 In order to use APM, you will need supporting software. For location
1779 and more information, read <file:Documentation/power/apm-acpi.txt>
1780 and the Battery Powered Linux mini-HOWTO, available from
1781 <http://www.tldp.org/docs.html#howto>.
1783 This driver does not spin down disk drives (see the hdparm(8)
1784 manpage ("man 8 hdparm") for that), and it doesn't turn off
1785 VESA-compliant "green" monitors.
1787 This driver does not support the TI 4000M TravelMate and the ACER
1788 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1789 desktop machines also don't have compliant BIOSes, and this driver
1790 may cause those machines to panic during the boot phase.
1792 Generally, if you don't have a battery in your machine, there isn't
1793 much point in using this driver and you should say N. If you get
1794 random kernel OOPSes or reboots that don't seem to be related to
1795 anything, try disabling/enabling this option (or disabling/enabling
1798 Some other things you should try when experiencing seemingly random,
1801 1) make sure that you have enough swap space and that it is
1803 2) pass the "no-hlt" option to the kernel
1804 3) switch on floating point emulation in the kernel and pass
1805 the "no387" option to the kernel
1806 4) pass the "floppy=nodma" option to the kernel
1807 5) pass the "mem=4M" option to the kernel (thereby disabling
1808 all but the first 4 MB of RAM)
1809 6) make sure that the CPU is not over clocked.
1810 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1811 8) disable the cache from your BIOS settings
1812 9) install a fan for the video card or exchange video RAM
1813 10) install a better fan for the CPU
1814 11) exchange RAM chips
1815 12) exchange the motherboard.
1817 To compile this driver as a module, choose M here: the
1818 module will be called apm.
1822 config APM_IGNORE_USER_SUSPEND
1823 bool "Ignore USER SUSPEND"
1825 This option will ignore USER SUSPEND requests. On machines with a
1826 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1827 series notebooks, it is necessary to say Y because of a BIOS bug.
1829 config APM_DO_ENABLE
1830 bool "Enable PM at boot time"
1832 Enable APM features at boot time. From page 36 of the APM BIOS
1833 specification: "When disabled, the APM BIOS does not automatically
1834 power manage devices, enter the Standby State, enter the Suspend
1835 State, or take power saving steps in response to CPU Idle calls."
1836 This driver will make CPU Idle calls when Linux is idle (unless this
1837 feature is turned off -- see "Do CPU IDLE calls", below). This
1838 should always save battery power, but more complicated APM features
1839 will be dependent on your BIOS implementation. You may need to turn
1840 this option off if your computer hangs at boot time when using APM
1841 support, or if it beeps continuously instead of suspending. Turn
1842 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1843 T400CDT. This is off by default since most machines do fine without
1847 bool "Make CPU Idle calls when idle"
1849 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1850 On some machines, this can activate improved power savings, such as
1851 a slowed CPU clock rate, when the machine is idle. These idle calls
1852 are made after the idle loop has run for some length of time (e.g.,
1853 333 mS). On some machines, this will cause a hang at boot time or
1854 whenever the CPU becomes idle. (On machines with more than one CPU,
1855 this option does nothing.)
1857 config APM_DISPLAY_BLANK
1858 bool "Enable console blanking using APM"
1860 Enable console blanking using the APM. Some laptops can use this to
1861 turn off the LCD backlight when the screen blanker of the Linux
1862 virtual console blanks the screen. Note that this is only used by
1863 the virtual console screen blanker, and won't turn off the backlight
1864 when using the X Window system. This also doesn't have anything to
1865 do with your VESA-compliant power-saving monitor. Further, this
1866 option doesn't work for all laptops -- it might not turn off your
1867 backlight at all, or it might print a lot of errors to the console,
1868 especially if you are using gpm.
1870 config APM_ALLOW_INTS
1871 bool "Allow interrupts during APM BIOS calls"
1873 Normally we disable external interrupts while we are making calls to
1874 the APM BIOS as a measure to lessen the effects of a badly behaving
1875 BIOS implementation. The BIOS should reenable interrupts if it
1876 needs to. Unfortunately, some BIOSes do not -- especially those in
1877 many of the newer IBM Thinkpads. If you experience hangs when you
1878 suspend, try setting this to Y. Otherwise, say N.
1882 source "drivers/cpufreq/Kconfig"
1884 source "drivers/cpuidle/Kconfig"
1886 source "drivers/idle/Kconfig"
1891 menu "Bus options (PCI etc.)"
1896 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1898 Find out whether you have a PCI motherboard. PCI is the name of a
1899 bus system, i.e. the way the CPU talks to the other stuff inside
1900 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1901 VESA. If you have PCI, say Y, otherwise N.
1904 prompt "PCI access mode"
1905 depends on X86_32 && PCI
1908 On PCI systems, the BIOS can be used to detect the PCI devices and
1909 determine their configuration. However, some old PCI motherboards
1910 have BIOS bugs and may crash if this is done. Also, some embedded
1911 PCI-based systems don't have any BIOS at all. Linux can also try to
1912 detect the PCI hardware directly without using the BIOS.
1914 With this option, you can specify how Linux should detect the
1915 PCI devices. If you choose "BIOS", the BIOS will be used,
1916 if you choose "Direct", the BIOS won't be used, and if you
1917 choose "MMConfig", then PCI Express MMCONFIG will be used.
1918 If you choose "Any", the kernel will try MMCONFIG, then the
1919 direct access method and falls back to the BIOS if that doesn't
1920 work. If unsure, go with the default, which is "Any".
1925 config PCI_GOMMCONFIG
1942 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1944 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1947 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1951 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1955 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1959 depends on PCI && XEN
1967 bool "Support mmconfig PCI config space access"
1968 depends on X86_64 && PCI && ACPI
1970 config PCI_CNB20LE_QUIRK
1971 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1973 depends on PCI && EXPERIMENTAL
1975 Read the PCI windows out of the CNB20LE host bridge. This allows
1976 PCI hotplug to work on systems with the CNB20LE chipset which do
1979 There's no public spec for this chipset, and this functionality
1980 is known to be incomplete.
1982 You should say N unless you know you need this.
1984 source "drivers/pci/pcie/Kconfig"
1986 source "drivers/pci/Kconfig"
1988 # x86_64 have no ISA slots, but can have ISA-style DMA.
1990 bool "ISA-style DMA support" if (X86_64 && EXPERT)
1993 Enables ISA-style DMA support for devices requiring such controllers.
2001 Find out whether you have ISA slots on your motherboard. ISA is the
2002 name of a bus system, i.e. the way the CPU talks to the other stuff
2003 inside your box. Other bus systems are PCI, EISA, MicroChannel
2004 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2005 newer boards don't support it. If you have ISA, say Y, otherwise N.
2011 The Extended Industry Standard Architecture (EISA) bus was
2012 developed as an open alternative to the IBM MicroChannel bus.
2014 The EISA bus provided some of the features of the IBM MicroChannel
2015 bus while maintaining backward compatibility with cards made for
2016 the older ISA bus. The EISA bus saw limited use between 1988 and
2017 1995 when it was made obsolete by the PCI bus.
2019 Say Y here if you are building a kernel for an EISA-based machine.
2023 source "drivers/eisa/Kconfig"
2026 tristate "NatSemi SCx200 support"
2028 This provides basic support for National Semiconductor's
2029 (now AMD's) Geode processors. The driver probes for the
2030 PCI-IDs of several on-chip devices, so its a good dependency
2031 for other scx200_* drivers.
2033 If compiled as a module, the driver is named scx200.
2035 config SCx200HR_TIMER
2036 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2040 This driver provides a clocksource built upon the on-chip
2041 27MHz high-resolution timer. Its also a workaround for
2042 NSC Geode SC-1100's buggy TSC, which loses time when the
2043 processor goes idle (as is done by the scheduler). The
2044 other workaround is idle=poll boot option.
2047 bool "One Laptop Per Child support"
2054 Add support for detecting the unique features of the OLPC
2058 bool "OLPC XO-1 Power Management"
2059 depends on OLPC && MFD_CS5535 && PM_SLEEP
2062 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2065 bool "OLPC XO-1 Real Time Clock"
2066 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2068 Add support for the XO-1 real time clock, which can be used as a
2069 programmable wakeup source.
2072 bool "OLPC XO-1 SCI extras"
2073 depends on OLPC && OLPC_XO1_PM
2078 Add support for SCI-based features of the OLPC XO-1 laptop:
2079 - EC-driven system wakeups
2083 - AC adapter status updates
2084 - Battery status updates
2086 config OLPC_XO15_SCI
2087 bool "OLPC XO-1.5 SCI extras"
2088 depends on OLPC && ACPI
2091 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2092 - EC-driven system wakeups
2093 - AC adapter status updates
2094 - Battery status updates
2097 bool "PCEngines ALIX System Support (LED setup)"
2100 This option enables system support for the PCEngines ALIX.
2101 At present this just sets up LEDs for GPIO control on
2102 ALIX2/3/6 boards. However, other system specific setup should
2105 Note: You must still enable the drivers for GPIO and LED support
2106 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2108 Note: You have to set alix.force=1 for boards with Award BIOS.
2111 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2114 This option enables system support for the Soekris Engineering net5501.
2117 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2121 This option enables system support for the Traverse Technologies GEOS.
2127 depends on CPU_SUP_AMD && PCI
2129 source "drivers/pcmcia/Kconfig"
2131 source "drivers/pci/hotplug/Kconfig"
2134 bool "RapidIO support"
2138 If you say Y here, the kernel will include drivers and
2139 infrastructure code to support RapidIO interconnect devices.
2141 source "drivers/rapidio/Kconfig"
2146 menu "Executable file formats / Emulations"
2148 source "fs/Kconfig.binfmt"
2150 config IA32_EMULATION
2151 bool "IA32 Emulation"
2153 select COMPAT_BINFMT_ELF
2155 Include code to run legacy 32-bit programs under a
2156 64-bit kernel. You should likely turn this on, unless you're
2157 100% sure that you don't have any 32-bit programs left.
2160 tristate "IA32 a.out support"
2161 depends on IA32_EMULATION
2163 Support old a.out binaries in the 32bit emulation.
2166 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2167 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2169 Include code to run binaries for the x32 native 32-bit ABI
2170 for 64-bit processors. An x32 process gets access to the
2171 full 64-bit register file and wide data path while leaving
2172 pointers at 32 bits for smaller memory footprint.
2174 You will need a recent binutils (2.22 or later) with
2175 elf32_x86_64 support enabled to compile a kernel with this
2180 depends on IA32_EMULATION || X86_X32
2181 select ARCH_WANT_OLD_COMPAT_IPC
2183 config COMPAT_FOR_U64_ALIGNMENT
2187 config SYSVIPC_COMPAT
2189 depends on COMPAT && SYSVIPC
2193 depends on COMPAT && KEYS
2199 config HAVE_ATOMIC_IOMAP
2203 config HAVE_TEXT_POKE_SMP
2205 select STOP_MACHINE if SMP
2207 config X86_DEV_DMA_OPS
2209 depends on X86_64 || STA2X11
2211 config X86_DMA_REMAP
2215 source "net/Kconfig"
2217 source "drivers/Kconfig"
2219 source "drivers/firmware/Kconfig"
2223 source "arch/x86/Kconfig.debug"
2225 source "security/Kconfig"
2227 source "crypto/Kconfig"
2229 source "arch/x86/kvm/Kconfig"
2231 source "lib/Kconfig"