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
19 select HAVE_AOUT if X86_32
20 select HAVE_UNSTABLE_SCHED_CLOCK
23 select HAVE_PCSPKR_PLATFORM
24 select HAVE_PERF_EVENTS
26 select HAVE_IOREMAP_PROT
29 select HAVE_MEMBLOCK_NODE_MAP
30 select ARCH_DISCARD_MEMBLOCK
31 select ARCH_WANT_OPTIONAL_GPIOLIB
32 select ARCH_WANT_FRAME_POINTERS
34 select HAVE_KRETPROBES
36 select HAVE_FTRACE_MCOUNT_RECORD
37 select HAVE_C_RECORDMCOUNT
38 select HAVE_DYNAMIC_FTRACE
39 select HAVE_FUNCTION_TRACER
40 select HAVE_FUNCTION_GRAPH_TRACER
41 select HAVE_FUNCTION_GRAPH_FP_TEST
42 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
43 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
44 select HAVE_SYSCALL_TRACEPOINTS
47 select HAVE_ARCH_TRACEHOOK
48 select HAVE_GENERIC_DMA_COHERENT if X86_32
49 select HAVE_EFFICIENT_UNALIGNED_ACCESS
50 select USER_STACKTRACE_SUPPORT
51 select HAVE_REGS_AND_STACK_ACCESS_API
52 select HAVE_DMA_API_DEBUG
53 select HAVE_KERNEL_GZIP
54 select HAVE_KERNEL_BZIP2
55 select HAVE_KERNEL_LZMA
57 select HAVE_KERNEL_LZO
58 select HAVE_HW_BREAKPOINT
59 select HAVE_MIXED_BREAKPOINTS_REGS
61 select HAVE_PERF_EVENTS_NMI
63 select HAVE_ALIGNED_STRUCT_PAGE if SLUB && !M386
64 select HAVE_CMPXCHG_LOCAL if !M386
65 select HAVE_CMPXCHG_DOUBLE
66 select HAVE_ARCH_KMEMCHECK
67 select HAVE_USER_RETURN_NOTIFIER
68 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
69 select HAVE_ARCH_JUMP_LABEL
70 select HAVE_TEXT_POKE_SMP
71 select HAVE_GENERIC_HARDIRQS
73 select GENERIC_FIND_FIRST_BIT
74 select GENERIC_IRQ_PROBE
75 select GENERIC_PENDING_IRQ if SMP
76 select GENERIC_IRQ_SHOW
77 select GENERIC_CLOCKEVENTS_MIN_ADJUST
78 select IRQ_FORCED_THREADING
79 select USE_GENERIC_SMP_HELPERS if SMP
80 select HAVE_BPF_JIT if (X86_64 && NET)
82 select ARCH_HAVE_NMI_SAFE_CMPXCHG
84 select DCACHE_WORD_ACCESS if !DEBUG_PAGEALLOC
86 config INSTRUCTION_DECODER
87 def_bool (KPROBES || PERF_EVENTS || UPROBES)
91 default "elf32-i386" if X86_32
92 default "elf64-x86-64" if X86_64
96 default "arch/x86/configs/i386_defconfig" if X86_32
97 default "arch/x86/configs/x86_64_defconfig" if X86_64
99 config GENERIC_CMOS_UPDATE
102 config CLOCKSOURCE_WATCHDOG
105 config GENERIC_CLOCKEVENTS
108 config ARCH_CLOCKSOURCE_DATA
112 config GENERIC_CLOCKEVENTS_BROADCAST
114 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
116 config LOCKDEP_SUPPORT
119 config STACKTRACE_SUPPORT
122 config HAVE_LATENCYTOP_SUPPORT
131 config NEED_DMA_MAP_STATE
132 def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG)
134 config NEED_SG_DMA_LENGTH
137 config GENERIC_ISA_DMA
143 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
145 config GENERIC_BUG_RELATIVE_POINTERS
148 config GENERIC_HWEIGHT
154 config ARCH_MAY_HAVE_PC_FDC
157 config RWSEM_GENERIC_SPINLOCK
160 config RWSEM_XCHGADD_ALGORITHM
163 config ARCH_HAS_CPU_IDLE_WAIT
166 config GENERIC_CALIBRATE_DELAY
169 config GENERIC_TIME_VSYSCALL
173 config ARCH_HAS_CPU_RELAX
176 config ARCH_HAS_DEFAULT_IDLE
179 config ARCH_HAS_CACHE_LINE_SIZE
182 config ARCH_HAS_CPU_AUTOPROBE
185 config HAVE_SETUP_PER_CPU_AREA
188 config NEED_PER_CPU_EMBED_FIRST_CHUNK
191 config NEED_PER_CPU_PAGE_FIRST_CHUNK
194 config ARCH_HIBERNATION_POSSIBLE
197 config ARCH_SUSPEND_POSSIBLE
208 config ARCH_SUPPORTS_OPTIMIZED_INLINING
211 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
214 config HAVE_INTEL_TXT
216 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
220 depends on X86_32 && SMP
224 depends on X86_64 && SMP
230 config X86_32_LAZY_GS
232 depends on X86_32 && !CC_STACKPROTECTOR
234 config ARCH_HWEIGHT_CFLAGS
236 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
237 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
242 config ARCH_CPU_PROBE_RELEASE
244 depends on HOTPLUG_CPU
246 config ARCH_SUPPORTS_UPROBES
249 source "init/Kconfig"
250 source "kernel/Kconfig.freezer"
252 menu "Processor type and features"
255 bool "DMA memory allocation support" if EXPERT
258 DMA memory allocation support allows devices with less than 32-bit
259 addressing to allocate within the first 16MB of address space.
260 Disable if no such devices will be used.
264 source "kernel/time/Kconfig"
267 bool "Symmetric multi-processing support"
269 This enables support for systems with more than one CPU. If you have
270 a system with only one CPU, like most personal computers, say N. If
271 you have a system with more than one CPU, say Y.
273 If you say N here, the kernel will run on single and multiprocessor
274 machines, but will use only one CPU of a multiprocessor machine. If
275 you say Y here, the kernel will run on many, but not all,
276 singleprocessor machines. On a singleprocessor machine, the kernel
277 will run faster if you say N here.
279 Note that if you say Y here and choose architecture "586" or
280 "Pentium" under "Processor family", the kernel will not work on 486
281 architectures. Similarly, multiprocessor kernels for the "PPro"
282 architecture may not work on all Pentium based boards.
284 People using multiprocessor machines who say Y here should also say
285 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
286 Management" code will be disabled if you say Y here.
288 See also <file:Documentation/x86/i386/IO-APIC.txt>,
289 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
290 <http://www.tldp.org/docs.html#howto>.
292 If you don't know what to do here, say N.
295 bool "Support x2apic"
296 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
298 This enables x2apic support on CPUs that have this feature.
300 This allows 32-bit apic IDs (so it can support very large systems),
301 and accesses the local apic via MSRs not via mmio.
303 If you don't know what to do here, say N.
306 bool "Enable MPS table" if ACPI
308 depends on X86_LOCAL_APIC
310 For old smp systems that do not have proper acpi support. Newer systems
311 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
314 bool "Support for big SMP systems with more than 8 CPUs"
315 depends on X86_32 && SMP
317 This option is needed for the systems that have more than 8 CPUs
320 config X86_EXTENDED_PLATFORM
321 bool "Support for extended (non-PC) x86 platforms"
324 If you disable this option then the kernel will only support
325 standard PC platforms. (which covers the vast majority of
328 If you enable this option then you'll be able to select support
329 for the following (non-PC) 32 bit x86 platforms:
333 SGI 320/540 (Visual Workstation)
334 Summit/EXA (IBM x440)
335 Unisys ES7000 IA32 series
336 Moorestown MID devices
338 If you have one of these systems, or if you want to build a
339 generic distribution kernel, say Y here - otherwise say N.
343 config X86_EXTENDED_PLATFORM
344 bool "Support for extended (non-PC) x86 platforms"
347 If you disable this option then the kernel will only support
348 standard PC platforms. (which covers the vast majority of
351 If you enable this option then you'll be able to select support
352 for the following (non-PC) 64 bit x86 platforms:
357 If you have one of these systems, or if you want to build a
358 generic distribution kernel, say Y here - otherwise say N.
360 # This is an alphabetically sorted list of 64 bit extended platforms
361 # Please maintain the alphabetic order if and when there are additions
363 bool "Numascale NumaChip"
365 depends on X86_EXTENDED_PLATFORM
368 depends on X86_X2APIC
370 Adds support for Numascale NumaChip large-SMP systems. Needed to
371 enable more than ~168 cores.
372 If you don't have one of these, you should say N here.
376 select PARAVIRT_GUEST
378 depends on X86_64 && PCI
379 depends on X86_EXTENDED_PLATFORM
381 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
382 supposed to run on these EM64T-based machines. Only choose this option
383 if you have one of these machines.
386 bool "SGI Ultraviolet"
388 depends on X86_EXTENDED_PLATFORM
390 depends on X86_X2APIC
392 This option is needed in order to support SGI Ultraviolet systems.
393 If you don't have one of these, you should say N here.
395 # Following is an alphabetically sorted list of 32 bit extended platforms
396 # Please maintain the alphabetic order if and when there are additions
399 bool "CE4100 TV platform"
401 depends on PCI_GODIRECT
403 depends on X86_EXTENDED_PLATFORM
404 select X86_REBOOTFIXUPS
406 select OF_EARLY_FLATTREE
409 Select for the Intel CE media processor (CE4100) SOC.
410 This option compiles in support for the CE4100 SOC for settop
411 boxes and media devices.
413 config X86_WANT_INTEL_MID
414 bool "Intel MID platform support"
416 depends on X86_EXTENDED_PLATFORM
418 Select to build a kernel capable of supporting Intel MID platform
419 systems which do not have the PCI legacy interfaces (Moorestown,
420 Medfield). If you are building for a PC class system say N here.
422 if X86_WANT_INTEL_MID
428 bool "Medfield MID platform"
431 depends on X86_IO_APIC
439 select X86_PLATFORM_DEVICES
440 select MFD_INTEL_MSIC
442 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
443 Internet Device(MID) platform.
444 Unlike standard x86 PCs, Medfield does not have many legacy devices
445 nor standard legacy replacement devices/features. e.g. Medfield does
446 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
451 bool "RDC R-321x SoC"
453 depends on X86_EXTENDED_PLATFORM
455 select X86_REBOOTFIXUPS
457 This option is needed for RDC R-321x system-on-chip, also known
459 If you don't have one of these chips, you should say N here.
461 config X86_32_NON_STANDARD
462 bool "Support non-standard 32-bit SMP architectures"
463 depends on X86_32 && SMP
464 depends on X86_EXTENDED_PLATFORM
466 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
467 subarchitectures. It is intended for a generic binary kernel.
468 if you select them all, kernel will probe it one by one. and will
471 # Alphabetically sorted list of Non standard 32 bit platforms
474 bool "NUMAQ (IBM/Sequent)"
475 depends on X86_32_NON_STANDARD
480 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
481 NUMA multiquad box. This changes the way that processors are
482 bootstrapped, and uses Clustered Logical APIC addressing mode instead
483 of Flat Logical. You will need a new lynxer.elf file to flash your
484 firmware with - send email to <Martin.Bligh@us.ibm.com>.
486 config X86_SUPPORTS_MEMORY_FAILURE
488 # MCE code calls memory_failure():
490 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
491 depends on !X86_NUMAQ
492 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
493 depends on X86_64 || !SPARSEMEM
494 select ARCH_SUPPORTS_MEMORY_FAILURE
497 bool "SGI 320/540 (Visual Workstation)"
498 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
499 depends on X86_32_NON_STANDARD
501 The SGI Visual Workstation series is an IA32-based workstation
502 based on SGI systems chips with some legacy PC hardware attached.
504 Say Y here to create a kernel to run on the SGI 320 or 540.
506 A kernel compiled for the Visual Workstation will run on general
507 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
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_BOOTMEM
1247 depends on X86_32 && NUMA
1249 config HAVE_ARCH_ALLOC_REMAP
1251 depends on X86_32 && NUMA
1253 config ARCH_HAVE_MEMORY_PRESENT
1255 depends on X86_32 && DISCONTIGMEM
1257 config NEED_NODE_MEMMAP_SIZE
1259 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1261 config ARCH_FLATMEM_ENABLE
1263 depends on X86_32 && !NUMA
1265 config ARCH_DISCONTIGMEM_ENABLE
1267 depends on NUMA && X86_32
1269 config ARCH_DISCONTIGMEM_DEFAULT
1271 depends on NUMA && X86_32
1273 config ARCH_SPARSEMEM_ENABLE
1275 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1276 select SPARSEMEM_STATIC if X86_32
1277 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1279 config ARCH_SPARSEMEM_DEFAULT
1283 config ARCH_SELECT_MEMORY_MODEL
1285 depends on ARCH_SPARSEMEM_ENABLE
1287 config ARCH_MEMORY_PROBE
1289 depends on MEMORY_HOTPLUG
1291 config ARCH_PROC_KCORE_TEXT
1293 depends on X86_64 && PROC_KCORE
1295 config ILLEGAL_POINTER_VALUE
1298 default 0xdead000000000000 if X86_64
1303 bool "Allocate 3rd-level pagetables from highmem"
1306 The VM uses one page table entry for each page of physical memory.
1307 For systems with a lot of RAM, this can be wasteful of precious
1308 low memory. Setting this option will put user-space page table
1309 entries in high memory.
1311 config X86_CHECK_BIOS_CORRUPTION
1312 bool "Check for low memory corruption"
1314 Periodically check for memory corruption in low memory, which
1315 is suspected to be caused by BIOS. Even when enabled in the
1316 configuration, it is disabled at runtime. Enable it by
1317 setting "memory_corruption_check=1" on the kernel command
1318 line. By default it scans the low 64k of memory every 60
1319 seconds; see the memory_corruption_check_size and
1320 memory_corruption_check_period parameters in
1321 Documentation/kernel-parameters.txt to adjust this.
1323 When enabled with the default parameters, this option has
1324 almost no overhead, as it reserves a relatively small amount
1325 of memory and scans it infrequently. It both detects corruption
1326 and prevents it from affecting the running system.
1328 It is, however, intended as a diagnostic tool; if repeatable
1329 BIOS-originated corruption always affects the same memory,
1330 you can use memmap= to prevent the kernel from using that
1333 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1334 bool "Set the default setting of memory_corruption_check"
1335 depends on X86_CHECK_BIOS_CORRUPTION
1338 Set whether the default state of memory_corruption_check is
1341 config X86_RESERVE_LOW
1342 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1346 Specify the amount of low memory to reserve for the BIOS.
1348 The first page contains BIOS data structures that the kernel
1349 must not use, so that page must always be reserved.
1351 By default we reserve the first 64K of physical RAM, as a
1352 number of BIOSes are known to corrupt that memory range
1353 during events such as suspend/resume or monitor cable
1354 insertion, so it must not be used by the kernel.
1356 You can set this to 4 if you are absolutely sure that you
1357 trust the BIOS to get all its memory reservations and usages
1358 right. If you know your BIOS have problems beyond the
1359 default 64K area, you can set this to 640 to avoid using the
1360 entire low memory range.
1362 If you have doubts about the BIOS (e.g. suspend/resume does
1363 not work or there's kernel crashes after certain hardware
1364 hotplug events) then you might want to enable
1365 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1366 typical corruption patterns.
1368 Leave this to the default value of 64 if you are unsure.
1370 config MATH_EMULATION
1372 prompt "Math emulation" if X86_32
1374 Linux can emulate a math coprocessor (used for floating point
1375 operations) if you don't have one. 486DX and Pentium processors have
1376 a math coprocessor built in, 486SX and 386 do not, unless you added
1377 a 487DX or 387, respectively. (The messages during boot time can
1378 give you some hints here ["man dmesg"].) Everyone needs either a
1379 coprocessor or this emulation.
1381 If you don't have a math coprocessor, you need to say Y here; if you
1382 say Y here even though you have a coprocessor, the coprocessor will
1383 be used nevertheless. (This behavior can be changed with the kernel
1384 command line option "no387", which comes handy if your coprocessor
1385 is broken. Try "man bootparam" or see the documentation of your boot
1386 loader (lilo or loadlin) about how to pass options to the kernel at
1387 boot time.) This means that it is a good idea to say Y here if you
1388 intend to use this kernel on different machines.
1390 More information about the internals of the Linux math coprocessor
1391 emulation can be found in <file:arch/x86/math-emu/README>.
1393 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1394 kernel, it won't hurt.
1398 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1400 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1401 the Memory Type Range Registers (MTRRs) may be used to control
1402 processor access to memory ranges. This is most useful if you have
1403 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1404 allows bus write transfers to be combined into a larger transfer
1405 before bursting over the PCI/AGP bus. This can increase performance
1406 of image write operations 2.5 times or more. Saying Y here creates a
1407 /proc/mtrr file which may be used to manipulate your processor's
1408 MTRRs. Typically the X server should use this.
1410 This code has a reasonably generic interface so that similar
1411 control registers on other processors can be easily supported
1414 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1415 Registers (ARRs) which provide a similar functionality to MTRRs. For
1416 these, the ARRs are used to emulate the MTRRs.
1417 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1418 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1419 write-combining. All of these processors are supported by this code
1420 and it makes sense to say Y here if you have one of them.
1422 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1423 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1424 can lead to all sorts of problems, so it's good to say Y here.
1426 You can safely say Y even if your machine doesn't have MTRRs, you'll
1427 just add about 9 KB to your kernel.
1429 See <file:Documentation/x86/mtrr.txt> for more information.
1431 config MTRR_SANITIZER
1433 prompt "MTRR cleanup support"
1436 Convert MTRR layout from continuous to discrete, so X drivers can
1437 add writeback entries.
1439 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1440 The largest mtrr entry size for a continuous block can be set with
1445 config MTRR_SANITIZER_ENABLE_DEFAULT
1446 int "MTRR cleanup enable value (0-1)"
1449 depends on MTRR_SANITIZER
1451 Enable mtrr cleanup default value
1453 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1454 int "MTRR cleanup spare reg num (0-7)"
1457 depends on MTRR_SANITIZER
1459 mtrr cleanup spare entries default, it can be changed via
1460 mtrr_spare_reg_nr=N on the kernel command line.
1464 prompt "x86 PAT support" if EXPERT
1467 Use PAT attributes to setup page level cache control.
1469 PATs are the modern equivalents of MTRRs and are much more
1470 flexible than MTRRs.
1472 Say N here if you see bootup problems (boot crash, boot hang,
1473 spontaneous reboots) or a non-working video driver.
1477 config ARCH_USES_PG_UNCACHED
1483 prompt "x86 architectural random number generator" if EXPERT
1485 Enable the x86 architectural RDRAND instruction
1486 (Intel Bull Mountain technology) to generate random numbers.
1487 If supported, this is a high bandwidth, cryptographically
1488 secure hardware random number generator.
1491 bool "EFI runtime service support"
1494 This enables the kernel to use EFI runtime services that are
1495 available (such as the EFI variable services).
1497 This option is only useful on systems that have EFI firmware.
1498 In addition, you should use the latest ELILO loader available
1499 at <http://elilo.sourceforge.net> in order to take advantage
1500 of EFI runtime services. However, even with this option, the
1501 resultant kernel should continue to boot on existing non-EFI
1505 bool "EFI stub support"
1508 This kernel feature allows a bzImage to be loaded directly
1509 by EFI firmware without the use of a bootloader.
1513 prompt "Enable seccomp to safely compute untrusted bytecode"
1515 This kernel feature is useful for number crunching applications
1516 that may need to compute untrusted bytecode during their
1517 execution. By using pipes or other transports made available to
1518 the process as file descriptors supporting the read/write
1519 syscalls, it's possible to isolate those applications in
1520 their own address space using seccomp. Once seccomp is
1521 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1522 and the task is only allowed to execute a few safe syscalls
1523 defined by each seccomp mode.
1525 If unsure, say Y. Only embedded should say N here.
1527 config CC_STACKPROTECTOR
1528 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1530 This option turns on the -fstack-protector GCC feature. This
1531 feature puts, at the beginning of functions, a canary value on
1532 the stack just before the return address, and validates
1533 the value just before actually returning. Stack based buffer
1534 overflows (that need to overwrite this return address) now also
1535 overwrite the canary, which gets detected and the attack is then
1536 neutralized via a kernel panic.
1538 This feature requires gcc version 4.2 or above, or a distribution
1539 gcc with the feature backported. Older versions are automatically
1540 detected and for those versions, this configuration option is
1541 ignored. (and a warning is printed during bootup)
1543 source kernel/Kconfig.hz
1546 bool "kexec system call"
1548 kexec is a system call that implements the ability to shutdown your
1549 current kernel, and to start another kernel. It is like a reboot
1550 but it is independent of the system firmware. And like a reboot
1551 you can start any kernel with it, not just Linux.
1553 The name comes from the similarity to the exec system call.
1555 It is an ongoing process to be certain the hardware in a machine
1556 is properly shutdown, so do not be surprised if this code does not
1557 initially work for you. It may help to enable device hotplugging
1558 support. As of this writing the exact hardware interface is
1559 strongly in flux, so no good recommendation can be made.
1562 bool "kernel crash dumps"
1563 depends on X86_64 || (X86_32 && HIGHMEM)
1565 Generate crash dump after being started by kexec.
1566 This should be normally only set in special crash dump kernels
1567 which are loaded in the main kernel with kexec-tools into
1568 a specially reserved region and then later executed after
1569 a crash by kdump/kexec. The crash dump kernel must be compiled
1570 to a memory address not used by the main kernel or BIOS using
1571 PHYSICAL_START, or it must be built as a relocatable image
1572 (CONFIG_RELOCATABLE=y).
1573 For more details see Documentation/kdump/kdump.txt
1576 bool "kexec jump (EXPERIMENTAL)"
1577 depends on EXPERIMENTAL
1578 depends on KEXEC && HIBERNATION
1580 Jump between original kernel and kexeced kernel and invoke
1581 code in physical address mode via KEXEC
1583 config PHYSICAL_START
1584 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1587 This gives the physical address where the kernel is loaded.
1589 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1590 bzImage will decompress itself to above physical address and
1591 run from there. Otherwise, bzImage will run from the address where
1592 it has been loaded by the boot loader and will ignore above physical
1595 In normal kdump cases one does not have to set/change this option
1596 as now bzImage can be compiled as a completely relocatable image
1597 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1598 address. This option is mainly useful for the folks who don't want
1599 to use a bzImage for capturing the crash dump and want to use a
1600 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1601 to be specifically compiled to run from a specific memory area
1602 (normally a reserved region) and this option comes handy.
1604 So if you are using bzImage for capturing the crash dump,
1605 leave the value here unchanged to 0x1000000 and set
1606 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1607 for capturing the crash dump change this value to start of
1608 the reserved region. In other words, it can be set based on
1609 the "X" value as specified in the "crashkernel=YM@XM"
1610 command line boot parameter passed to the panic-ed
1611 kernel. Please take a look at Documentation/kdump/kdump.txt
1612 for more details about crash dumps.
1614 Usage of bzImage for capturing the crash dump is recommended as
1615 one does not have to build two kernels. Same kernel can be used
1616 as production kernel and capture kernel. Above option should have
1617 gone away after relocatable bzImage support is introduced. But it
1618 is present because there are users out there who continue to use
1619 vmlinux for dump capture. This option should go away down the
1622 Don't change this unless you know what you are doing.
1625 bool "Build a relocatable kernel"
1628 This builds a kernel image that retains relocation information
1629 so it can be loaded someplace besides the default 1MB.
1630 The relocations tend to make the kernel binary about 10% larger,
1631 but are discarded at runtime.
1633 One use is for the kexec on panic case where the recovery kernel
1634 must live at a different physical address than the primary
1637 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1638 it has been loaded at and the compile time physical address
1639 (CONFIG_PHYSICAL_START) is ignored.
1641 # Relocation on x86-32 needs some additional build support
1642 config X86_NEED_RELOCS
1644 depends on X86_32 && RELOCATABLE
1646 config PHYSICAL_ALIGN
1647 hex "Alignment value to which kernel should be aligned" if X86_32
1649 range 0x2000 0x1000000
1651 This value puts the alignment restrictions on physical address
1652 where kernel is loaded and run from. Kernel is compiled for an
1653 address which meets above alignment restriction.
1655 If bootloader loads the kernel at a non-aligned address and
1656 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1657 address aligned to above value and run from there.
1659 If bootloader loads the kernel at a non-aligned address and
1660 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1661 load address and decompress itself to the address it has been
1662 compiled for and run from there. The address for which kernel is
1663 compiled already meets above alignment restrictions. Hence the
1664 end result is that kernel runs from a physical address meeting
1665 above alignment restrictions.
1667 Don't change this unless you know what you are doing.
1670 bool "Support for hot-pluggable CPUs"
1671 depends on SMP && HOTPLUG
1673 Say Y here to allow turning CPUs off and on. CPUs can be
1674 controlled through /sys/devices/system/cpu.
1675 ( Note: power management support will enable this option
1676 automatically on SMP systems. )
1677 Say N if you want to disable CPU hotplug.
1681 prompt "Compat VDSO support"
1682 depends on X86_32 || IA32_EMULATION
1684 Map the 32-bit VDSO to the predictable old-style address too.
1686 Say N here if you are running a sufficiently recent glibc
1687 version (2.3.3 or later), to remove the high-mapped
1688 VDSO mapping and to exclusively use the randomized VDSO.
1693 bool "Built-in kernel command line"
1695 Allow for specifying boot arguments to the kernel at
1696 build time. On some systems (e.g. embedded ones), it is
1697 necessary or convenient to provide some or all of the
1698 kernel boot arguments with the kernel itself (that is,
1699 to not rely on the boot loader to provide them.)
1701 To compile command line arguments into the kernel,
1702 set this option to 'Y', then fill in the
1703 the boot arguments in CONFIG_CMDLINE.
1705 Systems with fully functional boot loaders (i.e. non-embedded)
1706 should leave this option set to 'N'.
1709 string "Built-in kernel command string"
1710 depends on CMDLINE_BOOL
1713 Enter arguments here that should be compiled into the kernel
1714 image and used at boot time. If the boot loader provides a
1715 command line at boot time, it is appended to this string to
1716 form the full kernel command line, when the system boots.
1718 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1719 change this behavior.
1721 In most cases, the command line (whether built-in or provided
1722 by the boot loader) should specify the device for the root
1725 config CMDLINE_OVERRIDE
1726 bool "Built-in command line overrides boot loader arguments"
1727 depends on CMDLINE_BOOL
1729 Set this option to 'Y' to have the kernel ignore the boot loader
1730 command line, and use ONLY the built-in command line.
1732 This is used to work around broken boot loaders. This should
1733 be set to 'N' under normal conditions.
1737 config ARCH_ENABLE_MEMORY_HOTPLUG
1739 depends on X86_64 || (X86_32 && HIGHMEM)
1741 config ARCH_ENABLE_MEMORY_HOTREMOVE
1743 depends on MEMORY_HOTPLUG
1745 config USE_PERCPU_NUMA_NODE_ID
1749 menu "Power management and ACPI options"
1751 config ARCH_HIBERNATION_HEADER
1753 depends on X86_64 && HIBERNATION
1755 source "kernel/power/Kconfig"
1757 source "drivers/acpi/Kconfig"
1759 source "drivers/sfi/Kconfig"
1766 tristate "APM (Advanced Power Management) BIOS support"
1767 depends on X86_32 && PM_SLEEP
1769 APM is a BIOS specification for saving power using several different
1770 techniques. This is mostly useful for battery powered laptops with
1771 APM compliant BIOSes. If you say Y here, the system time will be
1772 reset after a RESUME operation, the /proc/apm device will provide
1773 battery status information, and user-space programs will receive
1774 notification of APM "events" (e.g. battery status change).
1776 If you select "Y" here, you can disable actual use of the APM
1777 BIOS by passing the "apm=off" option to the kernel at boot time.
1779 Note that the APM support is almost completely disabled for
1780 machines with more than one CPU.
1782 In order to use APM, you will need supporting software. For location
1783 and more information, read <file:Documentation/power/apm-acpi.txt>
1784 and the Battery Powered Linux mini-HOWTO, available from
1785 <http://www.tldp.org/docs.html#howto>.
1787 This driver does not spin down disk drives (see the hdparm(8)
1788 manpage ("man 8 hdparm") for that), and it doesn't turn off
1789 VESA-compliant "green" monitors.
1791 This driver does not support the TI 4000M TravelMate and the ACER
1792 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1793 desktop machines also don't have compliant BIOSes, and this driver
1794 may cause those machines to panic during the boot phase.
1796 Generally, if you don't have a battery in your machine, there isn't
1797 much point in using this driver and you should say N. If you get
1798 random kernel OOPSes or reboots that don't seem to be related to
1799 anything, try disabling/enabling this option (or disabling/enabling
1802 Some other things you should try when experiencing seemingly random,
1805 1) make sure that you have enough swap space and that it is
1807 2) pass the "no-hlt" option to the kernel
1808 3) switch on floating point emulation in the kernel and pass
1809 the "no387" option to the kernel
1810 4) pass the "floppy=nodma" option to the kernel
1811 5) pass the "mem=4M" option to the kernel (thereby disabling
1812 all but the first 4 MB of RAM)
1813 6) make sure that the CPU is not over clocked.
1814 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1815 8) disable the cache from your BIOS settings
1816 9) install a fan for the video card or exchange video RAM
1817 10) install a better fan for the CPU
1818 11) exchange RAM chips
1819 12) exchange the motherboard.
1821 To compile this driver as a module, choose M here: the
1822 module will be called apm.
1826 config APM_IGNORE_USER_SUSPEND
1827 bool "Ignore USER SUSPEND"
1829 This option will ignore USER SUSPEND requests. On machines with a
1830 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1831 series notebooks, it is necessary to say Y because of a BIOS bug.
1833 config APM_DO_ENABLE
1834 bool "Enable PM at boot time"
1836 Enable APM features at boot time. From page 36 of the APM BIOS
1837 specification: "When disabled, the APM BIOS does not automatically
1838 power manage devices, enter the Standby State, enter the Suspend
1839 State, or take power saving steps in response to CPU Idle calls."
1840 This driver will make CPU Idle calls when Linux is idle (unless this
1841 feature is turned off -- see "Do CPU IDLE calls", below). This
1842 should always save battery power, but more complicated APM features
1843 will be dependent on your BIOS implementation. You may need to turn
1844 this option off if your computer hangs at boot time when using APM
1845 support, or if it beeps continuously instead of suspending. Turn
1846 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1847 T400CDT. This is off by default since most machines do fine without
1851 bool "Make CPU Idle calls when idle"
1853 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1854 On some machines, this can activate improved power savings, such as
1855 a slowed CPU clock rate, when the machine is idle. These idle calls
1856 are made after the idle loop has run for some length of time (e.g.,
1857 333 mS). On some machines, this will cause a hang at boot time or
1858 whenever the CPU becomes idle. (On machines with more than one CPU,
1859 this option does nothing.)
1861 config APM_DISPLAY_BLANK
1862 bool "Enable console blanking using APM"
1864 Enable console blanking using the APM. Some laptops can use this to
1865 turn off the LCD backlight when the screen blanker of the Linux
1866 virtual console blanks the screen. Note that this is only used by
1867 the virtual console screen blanker, and won't turn off the backlight
1868 when using the X Window system. This also doesn't have anything to
1869 do with your VESA-compliant power-saving monitor. Further, this
1870 option doesn't work for all laptops -- it might not turn off your
1871 backlight at all, or it might print a lot of errors to the console,
1872 especially if you are using gpm.
1874 config APM_ALLOW_INTS
1875 bool "Allow interrupts during APM BIOS calls"
1877 Normally we disable external interrupts while we are making calls to
1878 the APM BIOS as a measure to lessen the effects of a badly behaving
1879 BIOS implementation. The BIOS should reenable interrupts if it
1880 needs to. Unfortunately, some BIOSes do not -- especially those in
1881 many of the newer IBM Thinkpads. If you experience hangs when you
1882 suspend, try setting this to Y. Otherwise, say N.
1886 source "drivers/cpufreq/Kconfig"
1888 source "drivers/cpuidle/Kconfig"
1890 source "drivers/idle/Kconfig"
1895 menu "Bus options (PCI etc.)"
1900 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1902 Find out whether you have a PCI motherboard. PCI is the name of a
1903 bus system, i.e. the way the CPU talks to the other stuff inside
1904 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1905 VESA. If you have PCI, say Y, otherwise N.
1908 prompt "PCI access mode"
1909 depends on X86_32 && PCI
1912 On PCI systems, the BIOS can be used to detect the PCI devices and
1913 determine their configuration. However, some old PCI motherboards
1914 have BIOS bugs and may crash if this is done. Also, some embedded
1915 PCI-based systems don't have any BIOS at all. Linux can also try to
1916 detect the PCI hardware directly without using the BIOS.
1918 With this option, you can specify how Linux should detect the
1919 PCI devices. If you choose "BIOS", the BIOS will be used,
1920 if you choose "Direct", the BIOS won't be used, and if you
1921 choose "MMConfig", then PCI Express MMCONFIG will be used.
1922 If you choose "Any", the kernel will try MMCONFIG, then the
1923 direct access method and falls back to the BIOS if that doesn't
1924 work. If unsure, go with the default, which is "Any".
1929 config PCI_GOMMCONFIG
1946 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1948 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1951 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1955 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1959 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1963 depends on PCI && XEN
1971 bool "Support mmconfig PCI config space access"
1972 depends on X86_64 && PCI && ACPI
1974 config PCI_CNB20LE_QUIRK
1975 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1977 depends on PCI && EXPERIMENTAL
1979 Read the PCI windows out of the CNB20LE host bridge. This allows
1980 PCI hotplug to work on systems with the CNB20LE chipset which do
1983 There's no public spec for this chipset, and this functionality
1984 is known to be incomplete.
1986 You should say N unless you know you need this.
1988 source "drivers/pci/pcie/Kconfig"
1990 source "drivers/pci/Kconfig"
1992 # x86_64 have no ISA slots, but can have ISA-style DMA.
1994 bool "ISA-style DMA support" if (X86_64 && EXPERT)
1997 Enables ISA-style DMA support for devices requiring such controllers.
2005 Find out whether you have ISA slots on your motherboard. ISA is the
2006 name of a bus system, i.e. the way the CPU talks to the other stuff
2007 inside your box. Other bus systems are PCI, EISA, MicroChannel
2008 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2009 newer boards don't support it. If you have ISA, say Y, otherwise N.
2015 The Extended Industry Standard Architecture (EISA) bus was
2016 developed as an open alternative to the IBM MicroChannel bus.
2018 The EISA bus provided some of the features of the IBM MicroChannel
2019 bus while maintaining backward compatibility with cards made for
2020 the older ISA bus. The EISA bus saw limited use between 1988 and
2021 1995 when it was made obsolete by the PCI bus.
2023 Say Y here if you are building a kernel for an EISA-based machine.
2027 source "drivers/eisa/Kconfig"
2032 MicroChannel Architecture is found in some IBM PS/2 machines and
2033 laptops. It is a bus system similar to PCI or ISA. See
2034 <file:Documentation/mca.txt> (and especially the web page given
2035 there) before attempting to build an MCA bus kernel.
2037 source "drivers/mca/Kconfig"
2040 tristate "NatSemi SCx200 support"
2042 This provides basic support for National Semiconductor's
2043 (now AMD's) Geode processors. The driver probes for the
2044 PCI-IDs of several on-chip devices, so its a good dependency
2045 for other scx200_* drivers.
2047 If compiled as a module, the driver is named scx200.
2049 config SCx200HR_TIMER
2050 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2054 This driver provides a clocksource built upon the on-chip
2055 27MHz high-resolution timer. Its also a workaround for
2056 NSC Geode SC-1100's buggy TSC, which loses time when the
2057 processor goes idle (as is done by the scheduler). The
2058 other workaround is idle=poll boot option.
2061 bool "One Laptop Per Child support"
2068 Add support for detecting the unique features of the OLPC
2072 bool "OLPC XO-1 Power Management"
2073 depends on OLPC && MFD_CS5535 && PM_SLEEP
2076 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2079 bool "OLPC XO-1 Real Time Clock"
2080 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2082 Add support for the XO-1 real time clock, which can be used as a
2083 programmable wakeup source.
2086 bool "OLPC XO-1 SCI extras"
2087 depends on OLPC && OLPC_XO1_PM
2092 Add support for SCI-based features of the OLPC XO-1 laptop:
2093 - EC-driven system wakeups
2097 - AC adapter status updates
2098 - Battery status updates
2100 config OLPC_XO15_SCI
2101 bool "OLPC XO-1.5 SCI extras"
2102 depends on OLPC && ACPI
2105 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2106 - EC-driven system wakeups
2107 - AC adapter status updates
2108 - Battery status updates
2111 bool "PCEngines ALIX System Support (LED setup)"
2114 This option enables system support for the PCEngines ALIX.
2115 At present this just sets up LEDs for GPIO control on
2116 ALIX2/3/6 boards. However, other system specific setup should
2119 Note: You must still enable the drivers for GPIO and LED support
2120 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2122 Note: You have to set alix.force=1 for boards with Award BIOS.
2125 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2128 This option enables system support for the Soekris Engineering net5501.
2131 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2135 This option enables system support for the Traverse Technologies GEOS.
2141 depends on CPU_SUP_AMD && PCI
2143 source "drivers/pcmcia/Kconfig"
2145 source "drivers/pci/hotplug/Kconfig"
2148 bool "RapidIO support"
2152 If you say Y here, the kernel will include drivers and
2153 infrastructure code to support RapidIO interconnect devices.
2155 source "drivers/rapidio/Kconfig"
2160 menu "Executable file formats / Emulations"
2162 source "fs/Kconfig.binfmt"
2164 config IA32_EMULATION
2165 bool "IA32 Emulation"
2167 select COMPAT_BINFMT_ELF
2169 Include code to run legacy 32-bit programs under a
2170 64-bit kernel. You should likely turn this on, unless you're
2171 100% sure that you don't have any 32-bit programs left.
2174 tristate "IA32 a.out support"
2175 depends on IA32_EMULATION
2177 Support old a.out binaries in the 32bit emulation.
2180 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2181 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2183 Include code to run binaries for the x32 native 32-bit ABI
2184 for 64-bit processors. An x32 process gets access to the
2185 full 64-bit register file and wide data path while leaving
2186 pointers at 32 bits for smaller memory footprint.
2188 You will need a recent binutils (2.22 or later) with
2189 elf32_x86_64 support enabled to compile a kernel with this
2194 depends on IA32_EMULATION || X86_X32
2195 select ARCH_WANT_OLD_COMPAT_IPC
2197 config COMPAT_FOR_U64_ALIGNMENT
2201 config SYSVIPC_COMPAT
2203 depends on COMPAT && SYSVIPC
2207 depends on COMPAT && KEYS
2213 config HAVE_ATOMIC_IOMAP
2217 config HAVE_TEXT_POKE_SMP
2219 select STOP_MACHINE if SMP
2221 source "net/Kconfig"
2223 source "drivers/Kconfig"
2225 source "drivers/firmware/Kconfig"
2229 source "arch/x86/Kconfig.debug"
2231 source "security/Kconfig"
2233 source "crypto/Kconfig"
2235 source "arch/x86/kvm/Kconfig"
2237 source "lib/Kconfig"