3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
18 select X86_DEV_DMA_OPS
23 select HAVE_AOUT if X86_32
24 select HAVE_UNSTABLE_SCHED_CLOCK
25 select ARCH_SUPPORTS_NUMA_BALANCING
26 select ARCH_WANTS_PROT_NUMA_PROT_NONE
29 select HAVE_PCSPKR_PLATFORM
30 select HAVE_PERF_EVENTS
31 select HAVE_IOREMAP_PROT
34 select HAVE_MEMBLOCK_NODE_MAP
35 select ARCH_DISCARD_MEMBLOCK
36 select ARCH_WANT_OPTIONAL_GPIOLIB
37 select ARCH_WANT_FRAME_POINTERS
39 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
40 select HAVE_KRETPROBES
42 select HAVE_FTRACE_MCOUNT_RECORD
43 select HAVE_FENTRY if X86_64
44 select HAVE_C_RECORDMCOUNT
45 select HAVE_DYNAMIC_FTRACE
46 select HAVE_FUNCTION_TRACER
47 select HAVE_FUNCTION_GRAPH_TRACER
48 select HAVE_FUNCTION_GRAPH_FP_TEST
49 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
50 select HAVE_SYSCALL_TRACEPOINTS
51 select SYSCTL_EXCEPTION_TRACE
54 select HAVE_ARCH_TRACEHOOK
55 select HAVE_GENERIC_DMA_COHERENT if X86_32
56 select HAVE_EFFICIENT_UNALIGNED_ACCESS
57 select USER_STACKTRACE_SUPPORT
58 select HAVE_REGS_AND_STACK_ACCESS_API
59 select HAVE_DMA_API_DEBUG
60 select HAVE_KERNEL_GZIP
61 select HAVE_KERNEL_BZIP2
62 select HAVE_KERNEL_LZMA
64 select HAVE_KERNEL_LZO
65 select HAVE_HW_BREAKPOINT
66 select HAVE_MIXED_BREAKPOINTS_REGS
68 select HAVE_PERF_EVENTS_NMI
70 select HAVE_PERF_USER_STACK_DUMP
71 select HAVE_DEBUG_KMEMLEAK
73 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
74 select HAVE_CMPXCHG_LOCAL
75 select HAVE_CMPXCHG_DOUBLE
76 select HAVE_ARCH_KMEMCHECK
77 select HAVE_USER_RETURN_NOTIFIER
78 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
79 select HAVE_ARCH_JUMP_LABEL
80 select HAVE_TEXT_POKE_SMP
81 select HAVE_GENERIC_HARDIRQS
82 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
84 select GENERIC_FIND_FIRST_BIT
85 select GENERIC_IRQ_PROBE
86 select GENERIC_PENDING_IRQ if SMP
87 select GENERIC_IRQ_SHOW
88 select GENERIC_CLOCKEVENTS_MIN_ADJUST
89 select IRQ_FORCED_THREADING
90 select USE_GENERIC_SMP_HELPERS if SMP
91 select HAVE_BPF_JIT if X86_64
92 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
94 select ARCH_HAVE_NMI_SAFE_CMPXCHG
96 select DCACHE_WORD_ACCESS
97 select GENERIC_SMP_IDLE_THREAD
98 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
99 select HAVE_ARCH_SECCOMP_FILTER
100 select BUILDTIME_EXTABLE_SORT
101 select GENERIC_CMOS_UPDATE
102 select CLOCKSOURCE_WATCHDOG
103 select GENERIC_CLOCKEVENTS
104 select ARCH_CLOCKSOURCE_DATA if X86_64
105 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
106 select GENERIC_TIME_VSYSCALL if X86_64
107 select KTIME_SCALAR if X86_32
108 select GENERIC_STRNCPY_FROM_USER
109 select GENERIC_STRNLEN_USER
110 select HAVE_CONTEXT_TRACKING if X86_64
111 select HAVE_IRQ_TIME_ACCOUNTING
112 select MODULES_USE_ELF_REL if X86_32
113 select MODULES_USE_ELF_RELA if X86_64
114 select CLONE_BACKWARDS if X86_32
115 select GENERIC_SIGALTSTACK
117 config INSTRUCTION_DECODER
119 depends on KPROBES || PERF_EVENTS || UPROBES
123 default "elf32-i386" if X86_32
124 default "elf64-x86-64" if X86_64
126 config ARCH_DEFCONFIG
128 default "arch/x86/configs/i386_defconfig" if X86_32
129 default "arch/x86/configs/x86_64_defconfig" if X86_64
131 config LOCKDEP_SUPPORT
134 config STACKTRACE_SUPPORT
137 config HAVE_LATENCYTOP_SUPPORT
146 config NEED_DMA_MAP_STATE
148 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
150 config NEED_SG_DMA_LENGTH
153 config GENERIC_ISA_DMA
155 depends on ISA_DMA_API
160 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
162 config GENERIC_BUG_RELATIVE_POINTERS
165 config GENERIC_HWEIGHT
171 config ARCH_MAY_HAVE_PC_FDC
173 depends on ISA_DMA_API
175 config RWSEM_XCHGADD_ALGORITHM
178 config GENERIC_CALIBRATE_DELAY
181 config ARCH_HAS_CPU_RELAX
184 config ARCH_HAS_DEFAULT_IDLE
187 config ARCH_HAS_CACHE_LINE_SIZE
190 config ARCH_HAS_CPU_AUTOPROBE
193 config HAVE_SETUP_PER_CPU_AREA
196 config NEED_PER_CPU_EMBED_FIRST_CHUNK
199 config NEED_PER_CPU_PAGE_FIRST_CHUNK
202 config ARCH_HIBERNATION_POSSIBLE
205 config ARCH_SUSPEND_POSSIBLE
216 config ARCH_SUPPORTS_OPTIMIZED_INLINING
219 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
222 config HAVE_INTEL_TXT
224 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
228 depends on X86_32 && SMP
232 depends on X86_64 && SMP
238 config X86_32_LAZY_GS
240 depends on X86_32 && !CC_STACKPROTECTOR
242 config ARCH_HWEIGHT_CFLAGS
244 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
245 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
247 config ARCH_CPU_PROBE_RELEASE
249 depends on HOTPLUG_CPU
251 config ARCH_SUPPORTS_UPROBES
254 source "init/Kconfig"
255 source "kernel/Kconfig.freezer"
257 menu "Processor type and features"
260 bool "DMA memory allocation support" if EXPERT
263 DMA memory allocation support allows devices with less than 32-bit
264 addressing to allocate within the first 16MB of address space.
265 Disable if no such devices will be used.
270 bool "Symmetric multi-processing support"
272 This enables support for systems with more than one CPU. If you have
273 a system with only one CPU, like most personal computers, say N. If
274 you have a system with more than one CPU, say Y.
276 If you say N here, the kernel will run on single and multiprocessor
277 machines, but will use only one CPU of a multiprocessor machine. If
278 you say Y here, the kernel will run on many, but not all,
279 singleprocessor machines. On a singleprocessor machine, the kernel
280 will run faster if you say N here.
282 Note that if you say Y here and choose architecture "586" or
283 "Pentium" under "Processor family", the kernel will not work on 486
284 architectures. Similarly, multiprocessor kernels for the "PPro"
285 architecture may not work on all Pentium based boards.
287 People using multiprocessor machines who say Y here should also say
288 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
289 Management" code will be disabled if you say Y here.
291 See also <file:Documentation/x86/i386/IO-APIC.txt>,
292 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
293 <http://www.tldp.org/docs.html#howto>.
295 If you don't know what to do here, say N.
298 bool "Support x2apic"
299 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
301 This enables x2apic support on CPUs that have this feature.
303 This allows 32-bit apic IDs (so it can support very large systems),
304 and accesses the local apic via MSRs not via mmio.
306 If you don't know what to do here, say N.
309 bool "Enable MPS table" if ACPI || SFI
311 depends on X86_LOCAL_APIC
313 For old smp systems that do not have proper acpi support. Newer systems
314 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
317 bool "Support for big SMP systems with more than 8 CPUs"
318 depends on X86_32 && SMP
320 This option is needed for the systems that have more than 8 CPUs
323 config X86_EXTENDED_PLATFORM
324 bool "Support for extended (non-PC) x86 platforms"
327 If you disable this option then the kernel will only support
328 standard PC platforms. (which covers the vast majority of
331 If you enable this option then you'll be able to select support
332 for the following (non-PC) 32 bit x86 platforms:
336 SGI 320/540 (Visual Workstation)
337 STA2X11-based (e.g. Northville)
338 Summit/EXA (IBM x440)
339 Unisys ES7000 IA32 series
340 Moorestown MID devices
342 If you have one of these systems, or if you want to build a
343 generic distribution kernel, say Y here - otherwise say N.
347 config X86_EXTENDED_PLATFORM
348 bool "Support for extended (non-PC) x86 platforms"
351 If you disable this option then the kernel will only support
352 standard PC platforms. (which covers the vast majority of
355 If you enable this option then you'll be able to select support
356 for the following (non-PC) 64 bit x86 platforms:
361 If you have one of these systems, or if you want to build a
362 generic distribution kernel, say Y here - otherwise say N.
364 # This is an alphabetically sorted list of 64 bit extended platforms
365 # Please maintain the alphabetic order if and when there are additions
367 bool "Numascale NumaChip"
369 depends on X86_EXTENDED_PLATFORM
372 depends on X86_X2APIC
373 depends on PCI_MMCONFIG
375 Adds support for Numascale NumaChip large-SMP systems. Needed to
376 enable more than ~168 cores.
377 If you don't have one of these, you should say N here.
381 select PARAVIRT_GUEST
383 depends on X86_64 && PCI
384 depends on X86_EXTENDED_PLATFORM
387 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
388 supposed to run on these EM64T-based machines. Only choose this option
389 if you have one of these machines.
392 bool "SGI Ultraviolet"
394 depends on X86_EXTENDED_PLATFORM
396 depends on X86_X2APIC
398 This option is needed in order to support SGI Ultraviolet systems.
399 If you don't have one of these, you should say N here.
401 # Following is an alphabetically sorted list of 32 bit extended platforms
402 # Please maintain the alphabetic order if and when there are additions
405 bool "CE4100 TV platform"
407 depends on PCI_GODIRECT
409 depends on X86_EXTENDED_PLATFORM
410 select X86_REBOOTFIXUPS
412 select OF_EARLY_FLATTREE
415 Select for the Intel CE media processor (CE4100) SOC.
416 This option compiles in support for the CE4100 SOC for settop
417 boxes and media devices.
419 config X86_WANT_INTEL_MID
420 bool "Intel MID platform support"
422 depends on X86_EXTENDED_PLATFORM
424 Select to build a kernel capable of supporting Intel MID platform
425 systems which do not have the PCI legacy interfaces (Moorestown,
426 Medfield). If you are building for a PC class system say N here.
428 if X86_WANT_INTEL_MID
434 bool "Medfield MID platform"
437 depends on X86_IO_APIC
445 select X86_PLATFORM_DEVICES
446 select MFD_INTEL_MSIC
448 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
449 Internet Device(MID) platform.
450 Unlike standard x86 PCs, Medfield does not have many legacy devices
451 nor standard legacy replacement devices/features. e.g. Medfield does
452 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
457 bool "RDC R-321x SoC"
459 depends on X86_EXTENDED_PLATFORM
461 select X86_REBOOTFIXUPS
463 This option is needed for RDC R-321x system-on-chip, also known
465 If you don't have one of these chips, you should say N here.
467 config X86_32_NON_STANDARD
468 bool "Support non-standard 32-bit SMP architectures"
469 depends on X86_32 && SMP
470 depends on X86_EXTENDED_PLATFORM
472 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
473 STA2X11, default subarchitectures. It is intended for a generic
474 binary kernel. If you select them all, kernel will probe it
475 one by one and will fallback to default.
477 # Alphabetically sorted list of Non standard 32 bit platforms
480 bool "NUMAQ (IBM/Sequent)"
481 depends on X86_32_NON_STANDARD
486 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
487 NUMA multiquad box. This changes the way that processors are
488 bootstrapped, and uses Clustered Logical APIC addressing mode instead
489 of Flat Logical. You will need a new lynxer.elf file to flash your
490 firmware with - send email to <Martin.Bligh@us.ibm.com>.
492 config X86_SUPPORTS_MEMORY_FAILURE
494 # MCE code calls memory_failure():
496 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
497 depends on !X86_NUMAQ
498 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
499 depends on X86_64 || !SPARSEMEM
500 select ARCH_SUPPORTS_MEMORY_FAILURE
503 bool "SGI 320/540 (Visual Workstation)"
504 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
505 depends on X86_32_NON_STANDARD
507 The SGI Visual Workstation series is an IA32-based workstation
508 based on SGI systems chips with some legacy PC hardware attached.
510 Say Y here to create a kernel to run on the SGI 320 or 540.
512 A kernel compiled for the Visual Workstation will run on general
513 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
516 bool "STA2X11 Companion Chip Support"
517 depends on X86_32_NON_STANDARD && PCI
518 select X86_DEV_DMA_OPS
522 select ARCH_REQUIRE_GPIOLIB
525 This adds support for boards based on the STA2X11 IO-Hub,
526 a.k.a. "ConneXt". The chip is used in place of the standard
527 PC chipset, so all "standard" peripherals are missing. If this
528 option is selected the kernel will still be able to boot on
529 standard PC machines.
532 bool "Summit/EXA (IBM x440)"
533 depends on X86_32_NON_STANDARD
535 This option is needed for IBM systems that use the Summit/EXA chipset.
536 In particular, it is needed for the x440.
539 bool "Unisys ES7000 IA32 series"
540 depends on X86_32_NON_STANDARD && X86_BIGSMP
542 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
543 supposed to run on an IA32-based Unisys ES7000 system.
546 tristate "Eurobraille/Iris poweroff module"
549 The Iris machines from EuroBraille do not have APM or ACPI support
550 to shut themselves down properly. A special I/O sequence is
551 needed to do so, which is what this module does at
554 This is only for Iris machines from EuroBraille.
558 config SCHED_OMIT_FRAME_POINTER
560 prompt "Single-depth WCHAN output"
563 Calculate simpler /proc/<PID>/wchan values. If this option
564 is disabled then wchan values will recurse back to the
565 caller function. This provides more accurate wchan values,
566 at the expense of slightly more scheduling overhead.
568 If in doubt, say "Y".
570 menuconfig PARAVIRT_GUEST
571 bool "Paravirtualized guest support"
573 Say Y here to get to see options related to running Linux under
574 various hypervisors. This option alone does not add any kernel code.
576 If you say N, all options in this submenu will be skipped and disabled.
580 config PARAVIRT_TIME_ACCOUNTING
581 bool "Paravirtual steal time accounting"
585 Select this option to enable fine granularity task steal time
586 accounting. Time spent executing other tasks in parallel with
587 the current vCPU is discounted from the vCPU power. To account for
588 that, there can be a small performance impact.
590 If in doubt, say N here.
592 source "arch/x86/xen/Kconfig"
595 bool "KVM Guest support (including kvmclock)"
598 select PARAVIRT_CLOCK
599 default y if PARAVIRT_GUEST
601 This option enables various optimizations for running under the KVM
602 hypervisor. It includes a paravirtualized clock, so that instead
603 of relying on a PIT (or probably other) emulation by the
604 underlying device model, the host provides the guest with
605 timing infrastructure such as time of day, and system time
607 source "arch/x86/lguest/Kconfig"
610 bool "Enable paravirtualization code"
612 This changes the kernel so it can modify itself when it is run
613 under a hypervisor, potentially improving performance significantly
614 over full virtualization. However, when run without a hypervisor
615 the kernel is theoretically slower and slightly larger.
617 config PARAVIRT_SPINLOCKS
618 bool "Paravirtualization layer for spinlocks"
619 depends on PARAVIRT && SMP && EXPERIMENTAL
621 Paravirtualized spinlocks allow a pvops backend to replace the
622 spinlock implementation with something virtualization-friendly
623 (for example, block the virtual CPU rather than spinning).
625 Unfortunately the downside is an up to 5% performance hit on
626 native kernels, with various workloads.
628 If you are unsure how to answer this question, answer N.
630 config PARAVIRT_CLOCK
635 config PARAVIRT_DEBUG
636 bool "paravirt-ops debugging"
637 depends on PARAVIRT && DEBUG_KERNEL
639 Enable to debug paravirt_ops internals. Specifically, BUG if
640 a paravirt_op is missing when it is called.
648 This option adds a kernel parameter 'memtest', which allows memtest
650 memtest=0, mean disabled; -- default
651 memtest=1, mean do 1 test pattern;
653 memtest=4, mean do 4 test patterns.
654 If you are unsure how to answer this question, answer N.
656 config X86_SUMMIT_NUMA
658 depends on X86_32 && NUMA && X86_32_NON_STANDARD
660 config X86_CYCLONE_TIMER
662 depends on X86_SUMMIT
664 source "arch/x86/Kconfig.cpu"
668 prompt "HPET Timer Support" if X86_32
670 Use the IA-PC HPET (High Precision Event Timer) to manage
671 time in preference to the PIT and RTC, if a HPET is
673 HPET is the next generation timer replacing legacy 8254s.
674 The HPET provides a stable time base on SMP
675 systems, unlike the TSC, but it is more expensive to access,
676 as it is off-chip. You can find the HPET spec at
677 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
679 You can safely choose Y here. However, HPET will only be
680 activated if the platform and the BIOS support this feature.
681 Otherwise the 8254 will be used for timing services.
683 Choose N to continue using the legacy 8254 timer.
685 config HPET_EMULATE_RTC
687 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
690 def_bool y if X86_INTEL_MID
691 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
693 depends on X86_INTEL_MID && SFI
695 APB timer is the replacement for 8254, HPET on X86 MID platforms.
696 The APBT provides a stable time base on SMP
697 systems, unlike the TSC, but it is more expensive to access,
698 as it is off-chip. APB timers are always running regardless of CPU
699 C states, they are used as per CPU clockevent device when possible.
701 # Mark as expert because too many people got it wrong.
702 # The code disables itself when not needed.
705 bool "Enable DMI scanning" if EXPERT
707 Enabled scanning of DMI to identify machine quirks. Say Y
708 here unless you have verified that your setup is not
709 affected by entries in the DMI blacklist. Required by PNP
713 bool "GART IOMMU support" if EXPERT
716 depends on X86_64 && PCI && AMD_NB
718 Support for full DMA access of devices with 32bit memory access only
719 on systems with more than 3GB. This is usually needed for USB,
720 sound, many IDE/SATA chipsets and some other devices.
721 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
722 based hardware IOMMU and a software bounce buffer based IOMMU used
723 on Intel systems and as fallback.
724 The code is only active when needed (enough memory and limited
725 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
729 bool "IBM Calgary IOMMU support"
731 depends on X86_64 && PCI && EXPERIMENTAL
733 Support for hardware IOMMUs in IBM's xSeries x366 and x460
734 systems. Needed to run systems with more than 3GB of memory
735 properly with 32-bit PCI devices that do not support DAC
736 (Double Address Cycle). Calgary also supports bus level
737 isolation, where all DMAs pass through the IOMMU. This
738 prevents them from going anywhere except their intended
739 destination. This catches hard-to-find kernel bugs and
740 mis-behaving drivers and devices that do not use the DMA-API
741 properly to set up their DMA buffers. The IOMMU can be
742 turned off at boot time with the iommu=off parameter.
743 Normally the kernel will make the right choice by itself.
746 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
748 prompt "Should Calgary be enabled by default?"
749 depends on CALGARY_IOMMU
751 Should Calgary be enabled by default? if you choose 'y', Calgary
752 will be used (if it exists). If you choose 'n', Calgary will not be
753 used even if it exists. If you choose 'n' and would like to use
754 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
757 # need this always selected by IOMMU for the VIA workaround
761 Support for software bounce buffers used on x86-64 systems
762 which don't have a hardware IOMMU. Using this PCI devices
763 which can only access 32-bits of memory can be used on systems
764 with more than 3 GB of memory.
769 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
772 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
773 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
774 select CPUMASK_OFFSTACK
776 Enable maximum number of CPUS and NUMA Nodes for this architecture.
780 int "Maximum number of CPUs" if SMP && !MAXSMP
781 range 2 8 if SMP && X86_32 && !X86_BIGSMP
782 range 2 512 if SMP && !MAXSMP
784 default "4096" if MAXSMP
785 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
788 This allows you to specify the maximum number of CPUs which this
789 kernel will support. The maximum supported value is 512 and the
790 minimum value which makes sense is 2.
792 This is purely to save memory - each supported CPU adds
793 approximately eight kilobytes to the kernel image.
796 bool "SMT (Hyperthreading) scheduler support"
799 SMT scheduler support improves the CPU scheduler's decision making
800 when dealing with Intel Pentium 4 chips with HyperThreading at a
801 cost of slightly increased overhead in some places. If unsure say
806 prompt "Multi-core scheduler support"
809 Multi-core scheduler support improves the CPU scheduler's decision
810 making when dealing with multi-core CPU chips at a cost of slightly
811 increased overhead in some places. If unsure say N here.
813 source "kernel/Kconfig.preempt"
816 bool "Local APIC support on uniprocessors"
817 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
819 A local APIC (Advanced Programmable Interrupt Controller) is an
820 integrated interrupt controller in the CPU. If you have a single-CPU
821 system which has a processor with a local APIC, you can say Y here to
822 enable and use it. If you say Y here even though your machine doesn't
823 have a local APIC, then the kernel will still run with no slowdown at
824 all. The local APIC supports CPU-generated self-interrupts (timer,
825 performance counters), and the NMI watchdog which detects hard
829 bool "IO-APIC support on uniprocessors"
830 depends on X86_UP_APIC
832 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
833 SMP-capable replacement for PC-style interrupt controllers. Most
834 SMP systems and many recent uniprocessor systems have one.
836 If you have a single-CPU system with an IO-APIC, you can say Y here
837 to use it. If you say Y here even though your machine doesn't have
838 an IO-APIC, then the kernel will still run with no slowdown at all.
840 config X86_LOCAL_APIC
842 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
846 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
848 config X86_VISWS_APIC
850 depends on X86_32 && X86_VISWS
852 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
853 bool "Reroute for broken boot IRQs"
854 depends on X86_IO_APIC
856 This option enables a workaround that fixes a source of
857 spurious interrupts. This is recommended when threaded
858 interrupt handling is used on systems where the generation of
859 superfluous "boot interrupts" cannot be disabled.
861 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
862 entry in the chipset's IO-APIC is masked (as, e.g. the RT
863 kernel does during interrupt handling). On chipsets where this
864 boot IRQ generation cannot be disabled, this workaround keeps
865 the original IRQ line masked so that only the equivalent "boot
866 IRQ" is delivered to the CPUs. The workaround also tells the
867 kernel to set up the IRQ handler on the boot IRQ line. In this
868 way only one interrupt is delivered to the kernel. Otherwise
869 the spurious second interrupt may cause the kernel to bring
870 down (vital) interrupt lines.
872 Only affects "broken" chipsets. Interrupt sharing may be
873 increased on these systems.
876 bool "Machine Check / overheating reporting"
879 Machine Check support allows the processor to notify the
880 kernel if it detects a problem (e.g. overheating, data corruption).
881 The action the kernel takes depends on the severity of the problem,
882 ranging from warning messages to halting the machine.
886 prompt "Intel MCE features"
887 depends on X86_MCE && X86_LOCAL_APIC
889 Additional support for intel specific MCE features such as
894 prompt "AMD MCE features"
895 depends on X86_MCE && X86_LOCAL_APIC
897 Additional support for AMD specific MCE features such as
898 the DRAM Error Threshold.
900 config X86_ANCIENT_MCE
901 bool "Support for old Pentium 5 / WinChip machine checks"
902 depends on X86_32 && X86_MCE
904 Include support for machine check handling on old Pentium 5 or WinChip
905 systems. These typically need to be enabled explicitely on the command
908 config X86_MCE_THRESHOLD
909 depends on X86_MCE_AMD || X86_MCE_INTEL
912 config X86_MCE_INJECT
914 tristate "Machine check injector support"
916 Provide support for injecting machine checks for testing purposes.
917 If you don't know what a machine check is and you don't do kernel
918 QA it is safe to say n.
920 config X86_THERMAL_VECTOR
922 depends on X86_MCE_INTEL
925 bool "Enable VM86 support" if EXPERT
929 This option is required by programs like DOSEMU to run 16-bit legacy
930 code on X86 processors. It also may be needed by software like
931 XFree86 to initialize some video cards via BIOS. Disabling this
932 option saves about 6k.
935 tristate "Toshiba Laptop support"
938 This adds a driver to safely access the System Management Mode of
939 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
940 not work on models with a Phoenix BIOS. The System Management Mode
941 is used to set the BIOS and power saving options on Toshiba portables.
943 For information on utilities to make use of this driver see the
944 Toshiba Linux utilities web site at:
945 <http://www.buzzard.org.uk/toshiba/>.
947 Say Y if you intend to run this kernel on a Toshiba portable.
951 tristate "Dell laptop support"
954 This adds a driver to safely access the System Management Mode
955 of the CPU on the Dell Inspiron 8000. The System Management Mode
956 is used to read cpu temperature and cooling fan status and to
957 control the fans on the I8K portables.
959 This driver has been tested only on the Inspiron 8000 but it may
960 also work with other Dell laptops. You can force loading on other
961 models by passing the parameter `force=1' to the module. Use at
964 For information on utilities to make use of this driver see the
965 I8K Linux utilities web site at:
966 <http://people.debian.org/~dz/i8k/>
968 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
971 config X86_REBOOTFIXUPS
972 bool "Enable X86 board specific fixups for reboot"
975 This enables chipset and/or board specific fixups to be done
976 in order to get reboot to work correctly. This is only needed on
977 some combinations of hardware and BIOS. The symptom, for which
978 this config is intended, is when reboot ends with a stalled/hung
981 Currently, the only fixup is for the Geode machines using
982 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
984 Say Y if you want to enable the fixup. Currently, it's safe to
985 enable this option even if you don't need it.
989 tristate "CPU microcode loading support"
993 If you say Y here, you will be able to update the microcode on
994 certain Intel and AMD processors. The Intel support is for the
995 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
996 Xeon etc. The AMD support is for families 0x10 and later. You will
997 obviously need the actual microcode binary data itself which is not
998 shipped with the Linux kernel.
1000 This option selects the general module only, you need to select
1001 at least one vendor specific module as well.
1003 To compile this driver as a module, choose M here: the module
1004 will be called microcode.
1006 config MICROCODE_INTEL
1007 bool "Intel microcode loading support"
1008 depends on MICROCODE
1012 This options enables microcode patch loading support for Intel
1015 For latest news and information on obtaining all the required
1016 Intel ingredients for this driver, check:
1017 <http://www.urbanmyth.org/microcode/>.
1019 config MICROCODE_AMD
1020 bool "AMD microcode loading support"
1021 depends on MICROCODE
1024 If you select this option, microcode patch loading support for AMD
1025 processors will be enabled.
1027 config MICROCODE_OLD_INTERFACE
1029 depends on MICROCODE
1032 tristate "/dev/cpu/*/msr - Model-specific register support"
1034 This device gives privileged processes access to the x86
1035 Model-Specific Registers (MSRs). It is a character device with
1036 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1037 MSR accesses are directed to a specific CPU on multi-processor
1041 tristate "/dev/cpu/*/cpuid - CPU information support"
1043 This device gives processes access to the x86 CPUID instruction to
1044 be executed on a specific processor. It is a character device
1045 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1049 prompt "High Memory Support"
1050 default HIGHMEM64G if X86_NUMAQ
1056 depends on !X86_NUMAQ
1058 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1059 However, the address space of 32-bit x86 processors is only 4
1060 Gigabytes large. That means that, if you have a large amount of
1061 physical memory, not all of it can be "permanently mapped" by the
1062 kernel. The physical memory that's not permanently mapped is called
1065 If you are compiling a kernel which will never run on a machine with
1066 more than 1 Gigabyte total physical RAM, answer "off" here (default
1067 choice and suitable for most users). This will result in a "3GB/1GB"
1068 split: 3GB are mapped so that each process sees a 3GB virtual memory
1069 space and the remaining part of the 4GB virtual memory space is used
1070 by the kernel to permanently map as much physical memory as
1073 If the machine has between 1 and 4 Gigabytes physical RAM, then
1076 If more than 4 Gigabytes is used then answer "64GB" here. This
1077 selection turns Intel PAE (Physical Address Extension) mode on.
1078 PAE implements 3-level paging on IA32 processors. PAE is fully
1079 supported by Linux, PAE mode is implemented on all recent Intel
1080 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1081 then the kernel will not boot on CPUs that don't support PAE!
1083 The actual amount of total physical memory will either be
1084 auto detected or can be forced by using a kernel command line option
1085 such as "mem=256M". (Try "man bootparam" or see the documentation of
1086 your boot loader (lilo or loadlin) about how to pass options to the
1087 kernel at boot time.)
1089 If unsure, say "off".
1093 depends on !X86_NUMAQ
1095 Select this if you have a 32-bit processor and between 1 and 4
1096 gigabytes of physical RAM.
1103 Select this if you have a 32-bit processor and more than 4
1104 gigabytes of physical RAM.
1109 depends on EXPERIMENTAL
1110 prompt "Memory split" if EXPERT
1114 Select the desired split between kernel and user memory.
1116 If the address range available to the kernel is less than the
1117 physical memory installed, the remaining memory will be available
1118 as "high memory". Accessing high memory is a little more costly
1119 than low memory, as it needs to be mapped into the kernel first.
1120 Note that increasing the kernel address space limits the range
1121 available to user programs, making the address space there
1122 tighter. Selecting anything other than the default 3G/1G split
1123 will also likely make your kernel incompatible with binary-only
1126 If you are not absolutely sure what you are doing, leave this
1130 bool "3G/1G user/kernel split"
1131 config VMSPLIT_3G_OPT
1133 bool "3G/1G user/kernel split (for full 1G low memory)"
1135 bool "2G/2G user/kernel split"
1136 config VMSPLIT_2G_OPT
1138 bool "2G/2G user/kernel split (for full 2G low memory)"
1140 bool "1G/3G user/kernel split"
1145 default 0xB0000000 if VMSPLIT_3G_OPT
1146 default 0x80000000 if VMSPLIT_2G
1147 default 0x78000000 if VMSPLIT_2G_OPT
1148 default 0x40000000 if VMSPLIT_1G
1154 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1157 bool "PAE (Physical Address Extension) Support"
1158 depends on X86_32 && !HIGHMEM4G
1160 PAE is required for NX support, and furthermore enables
1161 larger swapspace support for non-overcommit purposes. It
1162 has the cost of more pagetable lookup overhead, and also
1163 consumes more pagetable space per process.
1165 config ARCH_PHYS_ADDR_T_64BIT
1167 depends on X86_64 || X86_PAE
1169 config ARCH_DMA_ADDR_T_64BIT
1171 depends on X86_64 || HIGHMEM64G
1173 config DIRECT_GBPAGES
1174 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1178 Allow the kernel linear mapping to use 1GB pages on CPUs that
1179 support it. This can improve the kernel's performance a tiny bit by
1180 reducing TLB pressure. If in doubt, say "Y".
1182 # Common NUMA Features
1184 bool "Numa Memory Allocation and Scheduler Support"
1186 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1187 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1189 Enable NUMA (Non Uniform Memory Access) support.
1191 The kernel will try to allocate memory used by a CPU on the
1192 local memory controller of the CPU and add some more
1193 NUMA awareness to the kernel.
1195 For 64-bit this is recommended if the system is Intel Core i7
1196 (or later), AMD Opteron, or EM64T NUMA.
1198 For 32-bit this is only needed on (rare) 32-bit-only platforms
1199 that support NUMA topologies, such as NUMAQ / Summit, or if you
1200 boot a 32-bit kernel on a 64-bit NUMA platform.
1202 Otherwise, you should say N.
1204 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1205 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1209 prompt "Old style AMD Opteron NUMA detection"
1210 depends on X86_64 && NUMA && PCI
1212 Enable AMD NUMA node topology detection. You should say Y here if
1213 you have a multi processor AMD system. This uses an old method to
1214 read the NUMA configuration directly from the builtin Northbridge
1215 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1216 which also takes priority if both are compiled in.
1218 config X86_64_ACPI_NUMA
1220 prompt "ACPI NUMA detection"
1221 depends on X86_64 && NUMA && ACPI && PCI
1224 Enable ACPI SRAT based node topology detection.
1226 # Some NUMA nodes have memory ranges that span
1227 # other nodes. Even though a pfn is valid and
1228 # between a node's start and end pfns, it may not
1229 # reside on that node. See memmap_init_zone()
1231 config NODES_SPAN_OTHER_NODES
1233 depends on X86_64_ACPI_NUMA
1236 bool "NUMA emulation"
1239 Enable NUMA emulation. A flat machine will be split
1240 into virtual nodes when booted with "numa=fake=N", where N is the
1241 number of nodes. This is only useful for debugging.
1244 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1246 default "10" if MAXSMP
1247 default "6" if X86_64
1248 default "4" if X86_NUMAQ
1250 depends on NEED_MULTIPLE_NODES
1252 Specify the maximum number of NUMA Nodes available on the target
1253 system. Increases memory reserved to accommodate various tables.
1255 config HAVE_ARCH_ALLOC_REMAP
1257 depends on X86_32 && NUMA
1259 config ARCH_HAVE_MEMORY_PRESENT
1261 depends on X86_32 && DISCONTIGMEM
1263 config NEED_NODE_MEMMAP_SIZE
1265 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1267 config ARCH_FLATMEM_ENABLE
1269 depends on X86_32 && !NUMA
1271 config ARCH_DISCONTIGMEM_ENABLE
1273 depends on NUMA && X86_32
1275 config ARCH_DISCONTIGMEM_DEFAULT
1277 depends on NUMA && X86_32
1279 config ARCH_SPARSEMEM_ENABLE
1281 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1282 select SPARSEMEM_STATIC if X86_32
1283 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1285 config ARCH_SPARSEMEM_DEFAULT
1289 config ARCH_SELECT_MEMORY_MODEL
1291 depends on ARCH_SPARSEMEM_ENABLE
1293 config ARCH_MEMORY_PROBE
1295 depends on X86_64 && MEMORY_HOTPLUG
1297 config ARCH_PROC_KCORE_TEXT
1299 depends on X86_64 && PROC_KCORE
1301 config ILLEGAL_POINTER_VALUE
1304 default 0xdead000000000000 if X86_64
1309 bool "Allocate 3rd-level pagetables from highmem"
1312 The VM uses one page table entry for each page of physical memory.
1313 For systems with a lot of RAM, this can be wasteful of precious
1314 low memory. Setting this option will put user-space page table
1315 entries in high memory.
1317 config X86_CHECK_BIOS_CORRUPTION
1318 bool "Check for low memory corruption"
1320 Periodically check for memory corruption in low memory, which
1321 is suspected to be caused by BIOS. Even when enabled in the
1322 configuration, it is disabled at runtime. Enable it by
1323 setting "memory_corruption_check=1" on the kernel command
1324 line. By default it scans the low 64k of memory every 60
1325 seconds; see the memory_corruption_check_size and
1326 memory_corruption_check_period parameters in
1327 Documentation/kernel-parameters.txt to adjust this.
1329 When enabled with the default parameters, this option has
1330 almost no overhead, as it reserves a relatively small amount
1331 of memory and scans it infrequently. It both detects corruption
1332 and prevents it from affecting the running system.
1334 It is, however, intended as a diagnostic tool; if repeatable
1335 BIOS-originated corruption always affects the same memory,
1336 you can use memmap= to prevent the kernel from using that
1339 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1340 bool "Set the default setting of memory_corruption_check"
1341 depends on X86_CHECK_BIOS_CORRUPTION
1344 Set whether the default state of memory_corruption_check is
1347 config X86_RESERVE_LOW
1348 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1352 Specify the amount of low memory to reserve for the BIOS.
1354 The first page contains BIOS data structures that the kernel
1355 must not use, so that page must always be reserved.
1357 By default we reserve the first 64K of physical RAM, as a
1358 number of BIOSes are known to corrupt that memory range
1359 during events such as suspend/resume or monitor cable
1360 insertion, so it must not be used by the kernel.
1362 You can set this to 4 if you are absolutely sure that you
1363 trust the BIOS to get all its memory reservations and usages
1364 right. If you know your BIOS have problems beyond the
1365 default 64K area, you can set this to 640 to avoid using the
1366 entire low memory range.
1368 If you have doubts about the BIOS (e.g. suspend/resume does
1369 not work or there's kernel crashes after certain hardware
1370 hotplug events) then you might want to enable
1371 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1372 typical corruption patterns.
1374 Leave this to the default value of 64 if you are unsure.
1376 config MATH_EMULATION
1378 prompt "Math emulation" if X86_32
1380 Linux can emulate a math coprocessor (used for floating point
1381 operations) if you don't have one. 486DX and Pentium processors have
1382 a math coprocessor built in, 486SX and 386 do not, unless you added
1383 a 487DX or 387, respectively. (The messages during boot time can
1384 give you some hints here ["man dmesg"].) Everyone needs either a
1385 coprocessor or this emulation.
1387 If you don't have a math coprocessor, you need to say Y here; if you
1388 say Y here even though you have a coprocessor, the coprocessor will
1389 be used nevertheless. (This behavior can be changed with the kernel
1390 command line option "no387", which comes handy if your coprocessor
1391 is broken. Try "man bootparam" or see the documentation of your boot
1392 loader (lilo or loadlin) about how to pass options to the kernel at
1393 boot time.) This means that it is a good idea to say Y here if you
1394 intend to use this kernel on different machines.
1396 More information about the internals of the Linux math coprocessor
1397 emulation can be found in <file:arch/x86/math-emu/README>.
1399 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1400 kernel, it won't hurt.
1404 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1406 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1407 the Memory Type Range Registers (MTRRs) may be used to control
1408 processor access to memory ranges. This is most useful if you have
1409 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1410 allows bus write transfers to be combined into a larger transfer
1411 before bursting over the PCI/AGP bus. This can increase performance
1412 of image write operations 2.5 times or more. Saying Y here creates a
1413 /proc/mtrr file which may be used to manipulate your processor's
1414 MTRRs. Typically the X server should use this.
1416 This code has a reasonably generic interface so that similar
1417 control registers on other processors can be easily supported
1420 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1421 Registers (ARRs) which provide a similar functionality to MTRRs. For
1422 these, the ARRs are used to emulate the MTRRs.
1423 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1424 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1425 write-combining. All of these processors are supported by this code
1426 and it makes sense to say Y here if you have one of them.
1428 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1429 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1430 can lead to all sorts of problems, so it's good to say Y here.
1432 You can safely say Y even if your machine doesn't have MTRRs, you'll
1433 just add about 9 KB to your kernel.
1435 See <file:Documentation/x86/mtrr.txt> for more information.
1437 config MTRR_SANITIZER
1439 prompt "MTRR cleanup support"
1442 Convert MTRR layout from continuous to discrete, so X drivers can
1443 add writeback entries.
1445 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1446 The largest mtrr entry size for a continuous block can be set with
1451 config MTRR_SANITIZER_ENABLE_DEFAULT
1452 int "MTRR cleanup enable value (0-1)"
1455 depends on MTRR_SANITIZER
1457 Enable mtrr cleanup default value
1459 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1460 int "MTRR cleanup spare reg num (0-7)"
1463 depends on MTRR_SANITIZER
1465 mtrr cleanup spare entries default, it can be changed via
1466 mtrr_spare_reg_nr=N on the kernel command line.
1470 prompt "x86 PAT support" if EXPERT
1473 Use PAT attributes to setup page level cache control.
1475 PATs are the modern equivalents of MTRRs and are much more
1476 flexible than MTRRs.
1478 Say N here if you see bootup problems (boot crash, boot hang,
1479 spontaneous reboots) or a non-working video driver.
1483 config ARCH_USES_PG_UNCACHED
1489 prompt "x86 architectural random number generator" if EXPERT
1491 Enable the x86 architectural RDRAND instruction
1492 (Intel Bull Mountain technology) to generate random numbers.
1493 If supported, this is a high bandwidth, cryptographically
1494 secure hardware random number generator.
1498 prompt "Supervisor Mode Access Prevention" if EXPERT
1500 Supervisor Mode Access Prevention (SMAP) is a security
1501 feature in newer Intel processors. There is a small
1502 performance cost if this enabled and turned on; there is
1503 also a small increase in the kernel size if this is enabled.
1508 bool "EFI runtime service support"
1511 This enables the kernel to use EFI runtime services that are
1512 available (such as the EFI variable services).
1514 This option is only useful on systems that have EFI firmware.
1515 In addition, you should use the latest ELILO loader available
1516 at <http://elilo.sourceforge.net> in order to take advantage
1517 of EFI runtime services. However, even with this option, the
1518 resultant kernel should continue to boot on existing non-EFI
1522 bool "EFI stub support"
1525 This kernel feature allows a bzImage to be loaded directly
1526 by EFI firmware without the use of a bootloader.
1528 See Documentation/x86/efi-stub.txt for more information.
1532 prompt "Enable seccomp to safely compute untrusted bytecode"
1534 This kernel feature is useful for number crunching applications
1535 that may need to compute untrusted bytecode during their
1536 execution. By using pipes or other transports made available to
1537 the process as file descriptors supporting the read/write
1538 syscalls, it's possible to isolate those applications in
1539 their own address space using seccomp. Once seccomp is
1540 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1541 and the task is only allowed to execute a few safe syscalls
1542 defined by each seccomp mode.
1544 If unsure, say Y. Only embedded should say N here.
1546 config CC_STACKPROTECTOR
1547 bool "Enable -fstack-protector buffer overflow detection"
1549 This option turns on the -fstack-protector GCC feature. This
1550 feature puts, at the beginning of functions, a canary value on
1551 the stack just before the return address, and validates
1552 the value just before actually returning. Stack based buffer
1553 overflows (that need to overwrite this return address) now also
1554 overwrite the canary, which gets detected and the attack is then
1555 neutralized via a kernel panic.
1557 This feature requires gcc version 4.2 or above, or a distribution
1558 gcc with the feature backported. Older versions are automatically
1559 detected and for those versions, this configuration option is
1560 ignored. (and a warning is printed during bootup)
1562 source kernel/Kconfig.hz
1565 bool "kexec system call"
1567 kexec is a system call that implements the ability to shutdown your
1568 current kernel, and to start another kernel. It is like a reboot
1569 but it is independent of the system firmware. And like a reboot
1570 you can start any kernel with it, not just Linux.
1572 The name comes from the similarity to the exec system call.
1574 It is an ongoing process to be certain the hardware in a machine
1575 is properly shutdown, so do not be surprised if this code does not
1576 initially work for you. It may help to enable device hotplugging
1577 support. As of this writing the exact hardware interface is
1578 strongly in flux, so no good recommendation can be made.
1581 bool "kernel crash dumps"
1582 depends on X86_64 || (X86_32 && HIGHMEM)
1584 Generate crash dump after being started by kexec.
1585 This should be normally only set in special crash dump kernels
1586 which are loaded in the main kernel with kexec-tools into
1587 a specially reserved region and then later executed after
1588 a crash by kdump/kexec. The crash dump kernel must be compiled
1589 to a memory address not used by the main kernel or BIOS using
1590 PHYSICAL_START, or it must be built as a relocatable image
1591 (CONFIG_RELOCATABLE=y).
1592 For more details see Documentation/kdump/kdump.txt
1595 bool "kexec jump (EXPERIMENTAL)"
1596 depends on EXPERIMENTAL
1597 depends on KEXEC && HIBERNATION
1599 Jump between original kernel and kexeced kernel and invoke
1600 code in physical address mode via KEXEC
1602 config PHYSICAL_START
1603 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1606 This gives the physical address where the kernel is loaded.
1608 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1609 bzImage will decompress itself to above physical address and
1610 run from there. Otherwise, bzImage will run from the address where
1611 it has been loaded by the boot loader and will ignore above physical
1614 In normal kdump cases one does not have to set/change this option
1615 as now bzImage can be compiled as a completely relocatable image
1616 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1617 address. This option is mainly useful for the folks who don't want
1618 to use a bzImage for capturing the crash dump and want to use a
1619 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1620 to be specifically compiled to run from a specific memory area
1621 (normally a reserved region) and this option comes handy.
1623 So if you are using bzImage for capturing the crash dump,
1624 leave the value here unchanged to 0x1000000 and set
1625 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1626 for capturing the crash dump change this value to start of
1627 the reserved region. In other words, it can be set based on
1628 the "X" value as specified in the "crashkernel=YM@XM"
1629 command line boot parameter passed to the panic-ed
1630 kernel. Please take a look at Documentation/kdump/kdump.txt
1631 for more details about crash dumps.
1633 Usage of bzImage for capturing the crash dump is recommended as
1634 one does not have to build two kernels. Same kernel can be used
1635 as production kernel and capture kernel. Above option should have
1636 gone away after relocatable bzImage support is introduced. But it
1637 is present because there are users out there who continue to use
1638 vmlinux for dump capture. This option should go away down the
1641 Don't change this unless you know what you are doing.
1644 bool "Build a relocatable kernel"
1647 This builds a kernel image that retains relocation information
1648 so it can be loaded someplace besides the default 1MB.
1649 The relocations tend to make the kernel binary about 10% larger,
1650 but are discarded at runtime.
1652 One use is for the kexec on panic case where the recovery kernel
1653 must live at a different physical address than the primary
1656 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1657 it has been loaded at and the compile time physical address
1658 (CONFIG_PHYSICAL_START) is ignored.
1660 # Relocation on x86-32 needs some additional build support
1661 config X86_NEED_RELOCS
1663 depends on X86_32 && RELOCATABLE
1665 config PHYSICAL_ALIGN
1666 hex "Alignment value to which kernel should be aligned" if X86_32
1668 range 0x2000 0x1000000
1670 This value puts the alignment restrictions on physical address
1671 where kernel is loaded and run from. Kernel is compiled for an
1672 address which meets above alignment restriction.
1674 If bootloader loads the kernel at a non-aligned address and
1675 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1676 address aligned to above value and run from there.
1678 If bootloader loads the kernel at a non-aligned address and
1679 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1680 load address and decompress itself to the address it has been
1681 compiled for and run from there. The address for which kernel is
1682 compiled already meets above alignment restrictions. Hence the
1683 end result is that kernel runs from a physical address meeting
1684 above alignment restrictions.
1686 Don't change this unless you know what you are doing.
1689 bool "Support for hot-pluggable CPUs"
1690 depends on SMP && HOTPLUG
1692 Say Y here to allow turning CPUs off and on. CPUs can be
1693 controlled through /sys/devices/system/cpu.
1694 ( Note: power management support will enable this option
1695 automatically on SMP systems. )
1696 Say N if you want to disable CPU hotplug.
1698 config BOOTPARAM_HOTPLUG_CPU0
1699 bool "Set default setting of cpu0_hotpluggable"
1701 depends on HOTPLUG_CPU && EXPERIMENTAL
1703 Set whether default state of cpu0_hotpluggable is on or off.
1705 Say Y here to enable CPU0 hotplug by default. If this switch
1706 is turned on, there is no need to give cpu0_hotplug kernel
1707 parameter and the CPU0 hotplug feature is enabled by default.
1709 Please note: there are two known CPU0 dependencies if you want
1710 to enable the CPU0 hotplug feature either by this switch or by
1711 cpu0_hotplug kernel parameter.
1713 First, resume from hibernate or suspend always starts from CPU0.
1714 So hibernate and suspend are prevented if CPU0 is offline.
1716 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1717 offline if any interrupt can not migrate out of CPU0. There may
1718 be other CPU0 dependencies.
1720 Please make sure the dependencies are under your control before
1721 you enable this feature.
1723 Say N if you don't want to enable CPU0 hotplug feature by default.
1724 You still can enable the CPU0 hotplug feature at boot by kernel
1725 parameter cpu0_hotplug.
1727 config DEBUG_HOTPLUG_CPU0
1729 prompt "Debug CPU0 hotplug"
1730 depends on HOTPLUG_CPU && EXPERIMENTAL
1732 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1733 soon as possible and boots up userspace with CPU0 offlined. User
1734 can online CPU0 back after boot time.
1736 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1737 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1738 compilation or giving cpu0_hotplug kernel parameter at boot.
1744 prompt "Compat VDSO support"
1745 depends on X86_32 || IA32_EMULATION
1747 Map the 32-bit VDSO to the predictable old-style address too.
1749 Say N here if you are running a sufficiently recent glibc
1750 version (2.3.3 or later), to remove the high-mapped
1751 VDSO mapping and to exclusively use the randomized VDSO.
1756 bool "Built-in kernel command line"
1758 Allow for specifying boot arguments to the kernel at
1759 build time. On some systems (e.g. embedded ones), it is
1760 necessary or convenient to provide some or all of the
1761 kernel boot arguments with the kernel itself (that is,
1762 to not rely on the boot loader to provide them.)
1764 To compile command line arguments into the kernel,
1765 set this option to 'Y', then fill in the
1766 the boot arguments in CONFIG_CMDLINE.
1768 Systems with fully functional boot loaders (i.e. non-embedded)
1769 should leave this option set to 'N'.
1772 string "Built-in kernel command string"
1773 depends on CMDLINE_BOOL
1776 Enter arguments here that should be compiled into the kernel
1777 image and used at boot time. If the boot loader provides a
1778 command line at boot time, it is appended to this string to
1779 form the full kernel command line, when the system boots.
1781 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1782 change this behavior.
1784 In most cases, the command line (whether built-in or provided
1785 by the boot loader) should specify the device for the root
1788 config CMDLINE_OVERRIDE
1789 bool "Built-in command line overrides boot loader arguments"
1790 depends on CMDLINE_BOOL
1792 Set this option to 'Y' to have the kernel ignore the boot loader
1793 command line, and use ONLY the built-in command line.
1795 This is used to work around broken boot loaders. This should
1796 be set to 'N' under normal conditions.
1800 config ARCH_ENABLE_MEMORY_HOTPLUG
1802 depends on X86_64 || (X86_32 && HIGHMEM)
1804 config ARCH_ENABLE_MEMORY_HOTREMOVE
1806 depends on MEMORY_HOTPLUG
1808 config USE_PERCPU_NUMA_NODE_ID
1812 menu "Power management and ACPI options"
1814 config ARCH_HIBERNATION_HEADER
1816 depends on X86_64 && HIBERNATION
1818 source "kernel/power/Kconfig"
1820 source "drivers/acpi/Kconfig"
1822 source "drivers/sfi/Kconfig"
1829 tristate "APM (Advanced Power Management) BIOS support"
1830 depends on X86_32 && PM_SLEEP
1832 APM is a BIOS specification for saving power using several different
1833 techniques. This is mostly useful for battery powered laptops with
1834 APM compliant BIOSes. If you say Y here, the system time will be
1835 reset after a RESUME operation, the /proc/apm device will provide
1836 battery status information, and user-space programs will receive
1837 notification of APM "events" (e.g. battery status change).
1839 If you select "Y" here, you can disable actual use of the APM
1840 BIOS by passing the "apm=off" option to the kernel at boot time.
1842 Note that the APM support is almost completely disabled for
1843 machines with more than one CPU.
1845 In order to use APM, you will need supporting software. For location
1846 and more information, read <file:Documentation/power/apm-acpi.txt>
1847 and the Battery Powered Linux mini-HOWTO, available from
1848 <http://www.tldp.org/docs.html#howto>.
1850 This driver does not spin down disk drives (see the hdparm(8)
1851 manpage ("man 8 hdparm") for that), and it doesn't turn off
1852 VESA-compliant "green" monitors.
1854 This driver does not support the TI 4000M TravelMate and the ACER
1855 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1856 desktop machines also don't have compliant BIOSes, and this driver
1857 may cause those machines to panic during the boot phase.
1859 Generally, if you don't have a battery in your machine, there isn't
1860 much point in using this driver and you should say N. If you get
1861 random kernel OOPSes or reboots that don't seem to be related to
1862 anything, try disabling/enabling this option (or disabling/enabling
1865 Some other things you should try when experiencing seemingly random,
1868 1) make sure that you have enough swap space and that it is
1870 2) pass the "no-hlt" option to the kernel
1871 3) switch on floating point emulation in the kernel and pass
1872 the "no387" option to the kernel
1873 4) pass the "floppy=nodma" option to the kernel
1874 5) pass the "mem=4M" option to the kernel (thereby disabling
1875 all but the first 4 MB of RAM)
1876 6) make sure that the CPU is not over clocked.
1877 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1878 8) disable the cache from your BIOS settings
1879 9) install a fan for the video card or exchange video RAM
1880 10) install a better fan for the CPU
1881 11) exchange RAM chips
1882 12) exchange the motherboard.
1884 To compile this driver as a module, choose M here: the
1885 module will be called apm.
1889 config APM_IGNORE_USER_SUSPEND
1890 bool "Ignore USER SUSPEND"
1892 This option will ignore USER SUSPEND requests. On machines with a
1893 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1894 series notebooks, it is necessary to say Y because of a BIOS bug.
1896 config APM_DO_ENABLE
1897 bool "Enable PM at boot time"
1899 Enable APM features at boot time. From page 36 of the APM BIOS
1900 specification: "When disabled, the APM BIOS does not automatically
1901 power manage devices, enter the Standby State, enter the Suspend
1902 State, or take power saving steps in response to CPU Idle calls."
1903 This driver will make CPU Idle calls when Linux is idle (unless this
1904 feature is turned off -- see "Do CPU IDLE calls", below). This
1905 should always save battery power, but more complicated APM features
1906 will be dependent on your BIOS implementation. You may need to turn
1907 this option off if your computer hangs at boot time when using APM
1908 support, or if it beeps continuously instead of suspending. Turn
1909 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1910 T400CDT. This is off by default since most machines do fine without
1914 bool "Make CPU Idle calls when idle"
1916 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1917 On some machines, this can activate improved power savings, such as
1918 a slowed CPU clock rate, when the machine is idle. These idle calls
1919 are made after the idle loop has run for some length of time (e.g.,
1920 333 mS). On some machines, this will cause a hang at boot time or
1921 whenever the CPU becomes idle. (On machines with more than one CPU,
1922 this option does nothing.)
1924 config APM_DISPLAY_BLANK
1925 bool "Enable console blanking using APM"
1927 Enable console blanking using the APM. Some laptops can use this to
1928 turn off the LCD backlight when the screen blanker of the Linux
1929 virtual console blanks the screen. Note that this is only used by
1930 the virtual console screen blanker, and won't turn off the backlight
1931 when using the X Window system. This also doesn't have anything to
1932 do with your VESA-compliant power-saving monitor. Further, this
1933 option doesn't work for all laptops -- it might not turn off your
1934 backlight at all, or it might print a lot of errors to the console,
1935 especially if you are using gpm.
1937 config APM_ALLOW_INTS
1938 bool "Allow interrupts during APM BIOS calls"
1940 Normally we disable external interrupts while we are making calls to
1941 the APM BIOS as a measure to lessen the effects of a badly behaving
1942 BIOS implementation. The BIOS should reenable interrupts if it
1943 needs to. Unfortunately, some BIOSes do not -- especially those in
1944 many of the newer IBM Thinkpads. If you experience hangs when you
1945 suspend, try setting this to Y. Otherwise, say N.
1949 source "drivers/cpufreq/Kconfig"
1951 source "drivers/cpuidle/Kconfig"
1953 source "drivers/idle/Kconfig"
1958 menu "Bus options (PCI etc.)"
1963 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1965 Find out whether you have a PCI motherboard. PCI is the name of a
1966 bus system, i.e. the way the CPU talks to the other stuff inside
1967 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1968 VESA. If you have PCI, say Y, otherwise N.
1971 prompt "PCI access mode"
1972 depends on X86_32 && PCI
1975 On PCI systems, the BIOS can be used to detect the PCI devices and
1976 determine their configuration. However, some old PCI motherboards
1977 have BIOS bugs and may crash if this is done. Also, some embedded
1978 PCI-based systems don't have any BIOS at all. Linux can also try to
1979 detect the PCI hardware directly without using the BIOS.
1981 With this option, you can specify how Linux should detect the
1982 PCI devices. If you choose "BIOS", the BIOS will be used,
1983 if you choose "Direct", the BIOS won't be used, and if you
1984 choose "MMConfig", then PCI Express MMCONFIG will be used.
1985 If you choose "Any", the kernel will try MMCONFIG, then the
1986 direct access method and falls back to the BIOS if that doesn't
1987 work. If unsure, go with the default, which is "Any".
1992 config PCI_GOMMCONFIG
2009 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2011 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2014 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2018 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2022 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2026 depends on PCI && XEN
2034 bool "Support mmconfig PCI config space access"
2035 depends on X86_64 && PCI && ACPI
2037 config PCI_CNB20LE_QUIRK
2038 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2039 depends on PCI && EXPERIMENTAL
2041 Read the PCI windows out of the CNB20LE host bridge. This allows
2042 PCI hotplug to work on systems with the CNB20LE chipset which do
2045 There's no public spec for this chipset, and this functionality
2046 is known to be incomplete.
2048 You should say N unless you know you need this.
2050 source "drivers/pci/pcie/Kconfig"
2052 source "drivers/pci/Kconfig"
2054 # x86_64 have no ISA slots, but can have ISA-style DMA.
2056 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2059 Enables ISA-style DMA support for devices requiring such controllers.
2067 Find out whether you have ISA slots on your motherboard. ISA is the
2068 name of a bus system, i.e. the way the CPU talks to the other stuff
2069 inside your box. Other bus systems are PCI, EISA, MicroChannel
2070 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2071 newer boards don't support it. If you have ISA, say Y, otherwise N.
2077 The Extended Industry Standard Architecture (EISA) bus was
2078 developed as an open alternative to the IBM MicroChannel bus.
2080 The EISA bus provided some of the features of the IBM MicroChannel
2081 bus while maintaining backward compatibility with cards made for
2082 the older ISA bus. The EISA bus saw limited use between 1988 and
2083 1995 when it was made obsolete by the PCI bus.
2085 Say Y here if you are building a kernel for an EISA-based machine.
2089 source "drivers/eisa/Kconfig"
2092 tristate "NatSemi SCx200 support"
2094 This provides basic support for National Semiconductor's
2095 (now AMD's) Geode processors. The driver probes for the
2096 PCI-IDs of several on-chip devices, so its a good dependency
2097 for other scx200_* drivers.
2099 If compiled as a module, the driver is named scx200.
2101 config SCx200HR_TIMER
2102 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2106 This driver provides a clocksource built upon the on-chip
2107 27MHz high-resolution timer. Its also a workaround for
2108 NSC Geode SC-1100's buggy TSC, which loses time when the
2109 processor goes idle (as is done by the scheduler). The
2110 other workaround is idle=poll boot option.
2113 bool "One Laptop Per Child support"
2120 Add support for detecting the unique features of the OLPC
2124 bool "OLPC XO-1 Power Management"
2125 depends on OLPC && MFD_CS5535 && PM_SLEEP
2128 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2131 bool "OLPC XO-1 Real Time Clock"
2132 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2134 Add support for the XO-1 real time clock, which can be used as a
2135 programmable wakeup source.
2138 bool "OLPC XO-1 SCI extras"
2139 depends on OLPC && OLPC_XO1_PM
2144 Add support for SCI-based features of the OLPC XO-1 laptop:
2145 - EC-driven system wakeups
2149 - AC adapter status updates
2150 - Battery status updates
2152 config OLPC_XO15_SCI
2153 bool "OLPC XO-1.5 SCI extras"
2154 depends on OLPC && ACPI
2157 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2158 - EC-driven system wakeups
2159 - AC adapter status updates
2160 - Battery status updates
2163 bool "PCEngines ALIX System Support (LED setup)"
2166 This option enables system support for the PCEngines ALIX.
2167 At present this just sets up LEDs for GPIO control on
2168 ALIX2/3/6 boards. However, other system specific setup should
2171 Note: You must still enable the drivers for GPIO and LED support
2172 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2174 Note: You have to set alix.force=1 for boards with Award BIOS.
2177 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2180 This option enables system support for the Soekris Engineering net5501.
2183 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2187 This option enables system support for the Traverse Technologies GEOS.
2193 depends on CPU_SUP_AMD && PCI
2195 source "drivers/pcmcia/Kconfig"
2197 source "drivers/pci/hotplug/Kconfig"
2200 bool "RapidIO support"
2204 If you say Y here, the kernel will include drivers and
2205 infrastructure code to support RapidIO interconnect devices.
2207 source "drivers/rapidio/Kconfig"
2212 menu "Executable file formats / Emulations"
2214 source "fs/Kconfig.binfmt"
2216 config IA32_EMULATION
2217 bool "IA32 Emulation"
2219 select COMPAT_BINFMT_ELF
2222 Include code to run legacy 32-bit programs under a
2223 64-bit kernel. You should likely turn this on, unless you're
2224 100% sure that you don't have any 32-bit programs left.
2227 tristate "IA32 a.out support"
2228 depends on IA32_EMULATION
2230 Support old a.out binaries in the 32bit emulation.
2233 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2234 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2236 Include code to run binaries for the x32 native 32-bit ABI
2237 for 64-bit processors. An x32 process gets access to the
2238 full 64-bit register file and wide data path while leaving
2239 pointers at 32 bits for smaller memory footprint.
2241 You will need a recent binutils (2.22 or later) with
2242 elf32_x86_64 support enabled to compile a kernel with this
2247 depends on IA32_EMULATION || X86_X32
2248 select ARCH_WANT_OLD_COMPAT_IPC
2251 config COMPAT_FOR_U64_ALIGNMENT
2254 config SYSVIPC_COMPAT
2266 config HAVE_ATOMIC_IOMAP
2270 config HAVE_TEXT_POKE_SMP
2272 select STOP_MACHINE if SMP
2274 config X86_DEV_DMA_OPS
2276 depends on X86_64 || STA2X11
2278 config X86_DMA_REMAP
2282 source "net/Kconfig"
2284 source "drivers/Kconfig"
2286 source "drivers/firmware/Kconfig"
2290 source "arch/x86/Kconfig.debug"
2292 source "security/Kconfig"
2294 source "crypto/Kconfig"
2296 source "arch/x86/kvm/Kconfig"
2298 source "lib/Kconfig"
git.samba.org / sfrench / cifs-2.6.git / blob