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_KPROBES_ON_FTRACE
43 select HAVE_FTRACE_MCOUNT_RECORD
44 select HAVE_FENTRY if X86_64
45 select HAVE_C_RECORDMCOUNT
46 select HAVE_DYNAMIC_FTRACE
47 select HAVE_DYNAMIC_FTRACE_WITH_REGS
48 select HAVE_FUNCTION_TRACER
49 select HAVE_FUNCTION_GRAPH_TRACER
50 select HAVE_FUNCTION_GRAPH_FP_TEST
51 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
52 select HAVE_SYSCALL_TRACEPOINTS
53 select SYSCTL_EXCEPTION_TRACE
56 select HAVE_ARCH_TRACEHOOK
57 select HAVE_GENERIC_DMA_COHERENT if X86_32
58 select HAVE_EFFICIENT_UNALIGNED_ACCESS
59 select USER_STACKTRACE_SUPPORT
60 select HAVE_REGS_AND_STACK_ACCESS_API
61 select HAVE_DMA_API_DEBUG
62 select HAVE_KERNEL_GZIP
63 select HAVE_KERNEL_BZIP2
64 select HAVE_KERNEL_LZMA
66 select HAVE_KERNEL_LZO
67 select HAVE_HW_BREAKPOINT
68 select HAVE_MIXED_BREAKPOINTS_REGS
70 select HAVE_PERF_EVENTS_NMI
72 select HAVE_PERF_USER_STACK_DUMP
73 select HAVE_DEBUG_KMEMLEAK
75 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
76 select HAVE_CMPXCHG_LOCAL
77 select HAVE_CMPXCHG_DOUBLE
78 select HAVE_ARCH_KMEMCHECK
79 select HAVE_USER_RETURN_NOTIFIER
80 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
81 select HAVE_ARCH_JUMP_LABEL
82 select HAVE_TEXT_POKE_SMP
83 select HAVE_GENERIC_HARDIRQS
84 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
86 select GENERIC_FIND_FIRST_BIT
87 select GENERIC_IRQ_PROBE
88 select GENERIC_PENDING_IRQ if SMP
89 select GENERIC_IRQ_SHOW
90 select GENERIC_CLOCKEVENTS_MIN_ADJUST
91 select IRQ_FORCED_THREADING
92 select USE_GENERIC_SMP_HELPERS if SMP
93 select HAVE_BPF_JIT if X86_64
94 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
96 select ARCH_HAVE_NMI_SAFE_CMPXCHG
98 select DCACHE_WORD_ACCESS
99 select GENERIC_SMP_IDLE_THREAD
100 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
101 select HAVE_ARCH_SECCOMP_FILTER
102 select BUILDTIME_EXTABLE_SORT
103 select GENERIC_CMOS_UPDATE
104 select CLOCKSOURCE_WATCHDOG
105 select GENERIC_CLOCKEVENTS
106 select ARCH_CLOCKSOURCE_DATA if X86_64
107 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
108 select GENERIC_TIME_VSYSCALL if X86_64
109 select KTIME_SCALAR if X86_32
110 select ALWAYS_USE_PERSISTENT_CLOCK
111 select GENERIC_STRNCPY_FROM_USER
112 select GENERIC_STRNLEN_USER
113 select HAVE_CONTEXT_TRACKING if X86_64
114 select HAVE_IRQ_TIME_ACCOUNTING
115 select MODULES_USE_ELF_REL if X86_32
116 select MODULES_USE_ELF_RELA if X86_64
117 select CLONE_BACKWARDS if X86_32
118 select GENERIC_SIGALTSTACK
120 config INSTRUCTION_DECODER
122 depends on KPROBES || PERF_EVENTS || UPROBES
126 default "elf32-i386" if X86_32
127 default "elf64-x86-64" if X86_64
129 config ARCH_DEFCONFIG
131 default "arch/x86/configs/i386_defconfig" if X86_32
132 default "arch/x86/configs/x86_64_defconfig" if X86_64
134 config LOCKDEP_SUPPORT
137 config STACKTRACE_SUPPORT
140 config HAVE_LATENCYTOP_SUPPORT
149 config NEED_DMA_MAP_STATE
151 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
153 config NEED_SG_DMA_LENGTH
156 config GENERIC_ISA_DMA
158 depends on ISA_DMA_API
163 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
165 config GENERIC_BUG_RELATIVE_POINTERS
168 config GENERIC_HWEIGHT
174 config ARCH_MAY_HAVE_PC_FDC
176 depends on ISA_DMA_API
178 config RWSEM_XCHGADD_ALGORITHM
181 config GENERIC_CALIBRATE_DELAY
184 config ARCH_HAS_CPU_RELAX
187 config ARCH_HAS_DEFAULT_IDLE
190 config ARCH_HAS_CACHE_LINE_SIZE
193 config ARCH_HAS_CPU_AUTOPROBE
196 config HAVE_SETUP_PER_CPU_AREA
199 config NEED_PER_CPU_EMBED_FIRST_CHUNK
202 config NEED_PER_CPU_PAGE_FIRST_CHUNK
205 config ARCH_HIBERNATION_POSSIBLE
208 config ARCH_SUSPEND_POSSIBLE
219 config ARCH_SUPPORTS_OPTIMIZED_INLINING
222 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
225 config HAVE_INTEL_TXT
227 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
231 depends on X86_32 && SMP
235 depends on X86_64 && SMP
241 config X86_32_LAZY_GS
243 depends on X86_32 && !CC_STACKPROTECTOR
245 config ARCH_HWEIGHT_CFLAGS
247 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
248 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
250 config ARCH_CPU_PROBE_RELEASE
252 depends on HOTPLUG_CPU
254 config ARCH_SUPPORTS_UPROBES
257 source "init/Kconfig"
258 source "kernel/Kconfig.freezer"
260 menu "Processor type and features"
263 bool "DMA memory allocation support" if EXPERT
266 DMA memory allocation support allows devices with less than 32-bit
267 addressing to allocate within the first 16MB of address space.
268 Disable if no such devices will be used.
273 bool "Symmetric multi-processing support"
275 This enables support for systems with more than one CPU. If you have
276 a system with only one CPU, like most personal computers, say N. If
277 you have a system with more than one CPU, say Y.
279 If you say N here, the kernel will run on single and multiprocessor
280 machines, but will use only one CPU of a multiprocessor machine. If
281 you say Y here, the kernel will run on many, but not all,
282 singleprocessor machines. On a singleprocessor machine, the kernel
283 will run faster if you say N here.
285 Note that if you say Y here and choose architecture "586" or
286 "Pentium" under "Processor family", the kernel will not work on 486
287 architectures. Similarly, multiprocessor kernels for the "PPro"
288 architecture may not work on all Pentium based boards.
290 People using multiprocessor machines who say Y here should also say
291 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
292 Management" code will be disabled if you say Y here.
294 See also <file:Documentation/x86/i386/IO-APIC.txt>,
295 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
296 <http://www.tldp.org/docs.html#howto>.
298 If you don't know what to do here, say N.
301 bool "Support x2apic"
302 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
304 This enables x2apic support on CPUs that have this feature.
306 This allows 32-bit apic IDs (so it can support very large systems),
307 and accesses the local apic via MSRs not via mmio.
309 If you don't know what to do here, say N.
312 bool "Enable MPS table" if ACPI || SFI
314 depends on X86_LOCAL_APIC
316 For old smp systems that do not have proper acpi support. Newer systems
317 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
320 bool "Support for big SMP systems with more than 8 CPUs"
321 depends on X86_32 && SMP
323 This option is needed for the systems that have more than 8 CPUs
326 config X86_EXTENDED_PLATFORM
327 bool "Support for extended (non-PC) x86 platforms"
330 If you disable this option then the kernel will only support
331 standard PC platforms. (which covers the vast majority of
334 If you enable this option then you'll be able to select support
335 for the following (non-PC) 32 bit x86 platforms:
339 SGI 320/540 (Visual Workstation)
340 STA2X11-based (e.g. Northville)
341 Summit/EXA (IBM x440)
342 Unisys ES7000 IA32 series
343 Moorestown MID devices
345 If you have one of these systems, or if you want to build a
346 generic distribution kernel, say Y here - otherwise say N.
350 config X86_EXTENDED_PLATFORM
351 bool "Support for extended (non-PC) x86 platforms"
354 If you disable this option then the kernel will only support
355 standard PC platforms. (which covers the vast majority of
358 If you enable this option then you'll be able to select support
359 for the following (non-PC) 64 bit x86 platforms:
364 If you have one of these systems, or if you want to build a
365 generic distribution kernel, say Y here - otherwise say N.
367 # This is an alphabetically sorted list of 64 bit extended platforms
368 # Please maintain the alphabetic order if and when there are additions
370 bool "Numascale NumaChip"
372 depends on X86_EXTENDED_PLATFORM
375 depends on X86_X2APIC
376 depends on PCI_MMCONFIG
378 Adds support for Numascale NumaChip large-SMP systems. Needed to
379 enable more than ~168 cores.
380 If you don't have one of these, you should say N here.
384 select PARAVIRT_GUEST
386 depends on X86_64 && PCI
387 depends on X86_EXTENDED_PLATFORM
390 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
391 supposed to run on these EM64T-based machines. Only choose this option
392 if you have one of these machines.
395 bool "SGI Ultraviolet"
397 depends on X86_EXTENDED_PLATFORM
399 depends on X86_X2APIC
401 This option is needed in order to support SGI Ultraviolet systems.
402 If you don't have one of these, you should say N here.
404 # Following is an alphabetically sorted list of 32 bit extended platforms
405 # Please maintain the alphabetic order if and when there are additions
408 bool "CE4100 TV platform"
410 depends on PCI_GODIRECT
412 depends on X86_EXTENDED_PLATFORM
413 select X86_REBOOTFIXUPS
415 select OF_EARLY_FLATTREE
418 Select for the Intel CE media processor (CE4100) SOC.
419 This option compiles in support for the CE4100 SOC for settop
420 boxes and media devices.
422 config X86_WANT_INTEL_MID
423 bool "Intel MID platform support"
425 depends on X86_EXTENDED_PLATFORM
427 Select to build a kernel capable of supporting Intel MID platform
428 systems which do not have the PCI legacy interfaces (Moorestown,
429 Medfield). If you are building for a PC class system say N here.
431 if X86_WANT_INTEL_MID
437 bool "Medfield MID platform"
440 depends on X86_IO_APIC
448 select X86_PLATFORM_DEVICES
449 select MFD_INTEL_MSIC
451 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
452 Internet Device(MID) platform.
453 Unlike standard x86 PCs, Medfield does not have many legacy devices
454 nor standard legacy replacement devices/features. e.g. Medfield does
455 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
460 bool "RDC R-321x SoC"
462 depends on X86_EXTENDED_PLATFORM
464 select X86_REBOOTFIXUPS
466 This option is needed for RDC R-321x system-on-chip, also known
468 If you don't have one of these chips, you should say N here.
470 config X86_32_NON_STANDARD
471 bool "Support non-standard 32-bit SMP architectures"
472 depends on X86_32 && SMP
473 depends on X86_EXTENDED_PLATFORM
475 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
476 STA2X11, default subarchitectures. It is intended for a generic
477 binary kernel. If you select them all, kernel will probe it
478 one by one and will fallback to default.
480 # Alphabetically sorted list of Non standard 32 bit platforms
483 bool "NUMAQ (IBM/Sequent)"
484 depends on X86_32_NON_STANDARD
489 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
490 NUMA multiquad box. This changes the way that processors are
491 bootstrapped, and uses Clustered Logical APIC addressing mode instead
492 of Flat Logical. You will need a new lynxer.elf file to flash your
493 firmware with - send email to <Martin.Bligh@us.ibm.com>.
495 config X86_SUPPORTS_MEMORY_FAILURE
497 # MCE code calls memory_failure():
499 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
500 depends on !X86_NUMAQ
501 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
502 depends on X86_64 || !SPARSEMEM
503 select ARCH_SUPPORTS_MEMORY_FAILURE
506 bool "SGI 320/540 (Visual Workstation)"
507 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
508 depends on X86_32_NON_STANDARD
510 The SGI Visual Workstation series is an IA32-based workstation
511 based on SGI systems chips with some legacy PC hardware attached.
513 Say Y here to create a kernel to run on the SGI 320 or 540.
515 A kernel compiled for the Visual Workstation will run on general
516 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
519 bool "STA2X11 Companion Chip Support"
520 depends on X86_32_NON_STANDARD && PCI
521 select X86_DEV_DMA_OPS
525 select ARCH_REQUIRE_GPIOLIB
528 This adds support for boards based on the STA2X11 IO-Hub,
529 a.k.a. "ConneXt". The chip is used in place of the standard
530 PC chipset, so all "standard" peripherals are missing. If this
531 option is selected the kernel will still be able to boot on
532 standard PC machines.
535 bool "Summit/EXA (IBM x440)"
536 depends on X86_32_NON_STANDARD
538 This option is needed for IBM systems that use the Summit/EXA chipset.
539 In particular, it is needed for the x440.
542 bool "Unisys ES7000 IA32 series"
543 depends on X86_32_NON_STANDARD && X86_BIGSMP
545 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
546 supposed to run on an IA32-based Unisys ES7000 system.
549 tristate "Eurobraille/Iris poweroff module"
552 The Iris machines from EuroBraille do not have APM or ACPI support
553 to shut themselves down properly. A special I/O sequence is
554 needed to do so, which is what this module does at
557 This is only for Iris machines from EuroBraille.
561 config SCHED_OMIT_FRAME_POINTER
563 prompt "Single-depth WCHAN output"
566 Calculate simpler /proc/<PID>/wchan values. If this option
567 is disabled then wchan values will recurse back to the
568 caller function. This provides more accurate wchan values,
569 at the expense of slightly more scheduling overhead.
571 If in doubt, say "Y".
573 menuconfig PARAVIRT_GUEST
574 bool "Paravirtualized guest support"
576 Say Y here to get to see options related to running Linux under
577 various hypervisors. This option alone does not add any kernel code.
579 If you say N, all options in this submenu will be skipped and disabled.
583 config PARAVIRT_TIME_ACCOUNTING
584 bool "Paravirtual steal time accounting"
588 Select this option to enable fine granularity task steal time
589 accounting. Time spent executing other tasks in parallel with
590 the current vCPU is discounted from the vCPU power. To account for
591 that, there can be a small performance impact.
593 If in doubt, say N here.
595 source "arch/x86/xen/Kconfig"
598 bool "KVM Guest support (including kvmclock)"
601 select PARAVIRT_CLOCK
602 default y if PARAVIRT_GUEST
604 This option enables various optimizations for running under the KVM
605 hypervisor. It includes a paravirtualized clock, so that instead
606 of relying on a PIT (or probably other) emulation by the
607 underlying device model, the host provides the guest with
608 timing infrastructure such as time of day, and system time
610 source "arch/x86/lguest/Kconfig"
613 bool "Enable paravirtualization code"
615 This changes the kernel so it can modify itself when it is run
616 under a hypervisor, potentially improving performance significantly
617 over full virtualization. However, when run without a hypervisor
618 the kernel is theoretically slower and slightly larger.
620 config PARAVIRT_SPINLOCKS
621 bool "Paravirtualization layer for spinlocks"
622 depends on PARAVIRT && SMP && EXPERIMENTAL
624 Paravirtualized spinlocks allow a pvops backend to replace the
625 spinlock implementation with something virtualization-friendly
626 (for example, block the virtual CPU rather than spinning).
628 Unfortunately the downside is an up to 5% performance hit on
629 native kernels, with various workloads.
631 If you are unsure how to answer this question, answer N.
633 config PARAVIRT_CLOCK
638 config PARAVIRT_DEBUG
639 bool "paravirt-ops debugging"
640 depends on PARAVIRT && DEBUG_KERNEL
642 Enable to debug paravirt_ops internals. Specifically, BUG if
643 a paravirt_op is missing when it is called.
651 This option adds a kernel parameter 'memtest', which allows memtest
653 memtest=0, mean disabled; -- default
654 memtest=1, mean do 1 test pattern;
656 memtest=4, mean do 4 test patterns.
657 If you are unsure how to answer this question, answer N.
659 config X86_SUMMIT_NUMA
661 depends on X86_32 && NUMA && X86_32_NON_STANDARD
663 config X86_CYCLONE_TIMER
665 depends on X86_SUMMIT
667 source "arch/x86/Kconfig.cpu"
671 prompt "HPET Timer Support" if X86_32
673 Use the IA-PC HPET (High Precision Event Timer) to manage
674 time in preference to the PIT and RTC, if a HPET is
676 HPET is the next generation timer replacing legacy 8254s.
677 The HPET provides a stable time base on SMP
678 systems, unlike the TSC, but it is more expensive to access,
679 as it is off-chip. You can find the HPET spec at
680 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
682 You can safely choose Y here. However, HPET will only be
683 activated if the platform and the BIOS support this feature.
684 Otherwise the 8254 will be used for timing services.
686 Choose N to continue using the legacy 8254 timer.
688 config HPET_EMULATE_RTC
690 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
693 def_bool y if X86_INTEL_MID
694 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
696 depends on X86_INTEL_MID && SFI
698 APB timer is the replacement for 8254, HPET on X86 MID platforms.
699 The APBT provides a stable time base on SMP
700 systems, unlike the TSC, but it is more expensive to access,
701 as it is off-chip. APB timers are always running regardless of CPU
702 C states, they are used as per CPU clockevent device when possible.
704 # Mark as expert because too many people got it wrong.
705 # The code disables itself when not needed.
708 bool "Enable DMI scanning" if EXPERT
710 Enabled scanning of DMI to identify machine quirks. Say Y
711 here unless you have verified that your setup is not
712 affected by entries in the DMI blacklist. Required by PNP
716 bool "GART IOMMU support" if EXPERT
719 depends on X86_64 && PCI && AMD_NB
721 Support for full DMA access of devices with 32bit memory access only
722 on systems with more than 3GB. This is usually needed for USB,
723 sound, many IDE/SATA chipsets and some other devices.
724 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
725 based hardware IOMMU and a software bounce buffer based IOMMU used
726 on Intel systems and as fallback.
727 The code is only active when needed (enough memory and limited
728 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
732 bool "IBM Calgary IOMMU support"
734 depends on X86_64 && PCI && EXPERIMENTAL
736 Support for hardware IOMMUs in IBM's xSeries x366 and x460
737 systems. Needed to run systems with more than 3GB of memory
738 properly with 32-bit PCI devices that do not support DAC
739 (Double Address Cycle). Calgary also supports bus level
740 isolation, where all DMAs pass through the IOMMU. This
741 prevents them from going anywhere except their intended
742 destination. This catches hard-to-find kernel bugs and
743 mis-behaving drivers and devices that do not use the DMA-API
744 properly to set up their DMA buffers. The IOMMU can be
745 turned off at boot time with the iommu=off parameter.
746 Normally the kernel will make the right choice by itself.
749 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
751 prompt "Should Calgary be enabled by default?"
752 depends on CALGARY_IOMMU
754 Should Calgary be enabled by default? if you choose 'y', Calgary
755 will be used (if it exists). If you choose 'n', Calgary will not be
756 used even if it exists. If you choose 'n' and would like to use
757 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
760 # need this always selected by IOMMU for the VIA workaround
764 Support for software bounce buffers used on x86-64 systems
765 which don't have a hardware IOMMU. Using this PCI devices
766 which can only access 32-bits of memory can be used on systems
767 with more than 3 GB of memory.
772 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
775 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
776 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
777 select CPUMASK_OFFSTACK
779 Enable maximum number of CPUS and NUMA Nodes for this architecture.
783 int "Maximum number of CPUs" if SMP && !MAXSMP
784 range 2 8 if SMP && X86_32 && !X86_BIGSMP
785 range 2 512 if SMP && !MAXSMP
787 default "4096" if MAXSMP
788 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
791 This allows you to specify the maximum number of CPUs which this
792 kernel will support. The maximum supported value is 512 and the
793 minimum value which makes sense is 2.
795 This is purely to save memory - each supported CPU adds
796 approximately eight kilobytes to the kernel image.
799 bool "SMT (Hyperthreading) scheduler support"
802 SMT scheduler support improves the CPU scheduler's decision making
803 when dealing with Intel Pentium 4 chips with HyperThreading at a
804 cost of slightly increased overhead in some places. If unsure say
809 prompt "Multi-core scheduler support"
812 Multi-core scheduler support improves the CPU scheduler's decision
813 making when dealing with multi-core CPU chips at a cost of slightly
814 increased overhead in some places. If unsure say N here.
816 source "kernel/Kconfig.preempt"
819 bool "Local APIC support on uniprocessors"
820 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
822 A local APIC (Advanced Programmable Interrupt Controller) is an
823 integrated interrupt controller in the CPU. If you have a single-CPU
824 system which has a processor with a local APIC, you can say Y here to
825 enable and use it. If you say Y here even though your machine doesn't
826 have a local APIC, then the kernel will still run with no slowdown at
827 all. The local APIC supports CPU-generated self-interrupts (timer,
828 performance counters), and the NMI watchdog which detects hard
832 bool "IO-APIC support on uniprocessors"
833 depends on X86_UP_APIC
835 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
836 SMP-capable replacement for PC-style interrupt controllers. Most
837 SMP systems and many recent uniprocessor systems have one.
839 If you have a single-CPU system with an IO-APIC, you can say Y here
840 to use it. If you say Y here even though your machine doesn't have
841 an IO-APIC, then the kernel will still run with no slowdown at all.
843 config X86_LOCAL_APIC
845 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
849 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
851 config X86_VISWS_APIC
853 depends on X86_32 && X86_VISWS
855 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
856 bool "Reroute for broken boot IRQs"
857 depends on X86_IO_APIC
859 This option enables a workaround that fixes a source of
860 spurious interrupts. This is recommended when threaded
861 interrupt handling is used on systems where the generation of
862 superfluous "boot interrupts" cannot be disabled.
864 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
865 entry in the chipset's IO-APIC is masked (as, e.g. the RT
866 kernel does during interrupt handling). On chipsets where this
867 boot IRQ generation cannot be disabled, this workaround keeps
868 the original IRQ line masked so that only the equivalent "boot
869 IRQ" is delivered to the CPUs. The workaround also tells the
870 kernel to set up the IRQ handler on the boot IRQ line. In this
871 way only one interrupt is delivered to the kernel. Otherwise
872 the spurious second interrupt may cause the kernel to bring
873 down (vital) interrupt lines.
875 Only affects "broken" chipsets. Interrupt sharing may be
876 increased on these systems.
879 bool "Machine Check / overheating reporting"
882 Machine Check support allows the processor to notify the
883 kernel if it detects a problem (e.g. overheating, data corruption).
884 The action the kernel takes depends on the severity of the problem,
885 ranging from warning messages to halting the machine.
889 prompt "Intel MCE features"
890 depends on X86_MCE && X86_LOCAL_APIC
892 Additional support for intel specific MCE features such as
897 prompt "AMD MCE features"
898 depends on X86_MCE && X86_LOCAL_APIC
900 Additional support for AMD specific MCE features such as
901 the DRAM Error Threshold.
903 config X86_ANCIENT_MCE
904 bool "Support for old Pentium 5 / WinChip machine checks"
905 depends on X86_32 && X86_MCE
907 Include support for machine check handling on old Pentium 5 or WinChip
908 systems. These typically need to be enabled explicitely on the command
911 config X86_MCE_THRESHOLD
912 depends on X86_MCE_AMD || X86_MCE_INTEL
915 config X86_MCE_INJECT
917 tristate "Machine check injector support"
919 Provide support for injecting machine checks for testing purposes.
920 If you don't know what a machine check is and you don't do kernel
921 QA it is safe to say n.
923 config X86_THERMAL_VECTOR
925 depends on X86_MCE_INTEL
928 bool "Enable VM86 support" if EXPERT
932 This option is required by programs like DOSEMU to run 16-bit legacy
933 code on X86 processors. It also may be needed by software like
934 XFree86 to initialize some video cards via BIOS. Disabling this
935 option saves about 6k.
938 tristate "Toshiba Laptop support"
941 This adds a driver to safely access the System Management Mode of
942 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
943 not work on models with a Phoenix BIOS. The System Management Mode
944 is used to set the BIOS and power saving options on Toshiba portables.
946 For information on utilities to make use of this driver see the
947 Toshiba Linux utilities web site at:
948 <http://www.buzzard.org.uk/toshiba/>.
950 Say Y if you intend to run this kernel on a Toshiba portable.
954 tristate "Dell laptop support"
957 This adds a driver to safely access the System Management Mode
958 of the CPU on the Dell Inspiron 8000. The System Management Mode
959 is used to read cpu temperature and cooling fan status and to
960 control the fans on the I8K portables.
962 This driver has been tested only on the Inspiron 8000 but it may
963 also work with other Dell laptops. You can force loading on other
964 models by passing the parameter `force=1' to the module. Use at
967 For information on utilities to make use of this driver see the
968 I8K Linux utilities web site at:
969 <http://people.debian.org/~dz/i8k/>
971 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
974 config X86_REBOOTFIXUPS
975 bool "Enable X86 board specific fixups for reboot"
978 This enables chipset and/or board specific fixups to be done
979 in order to get reboot to work correctly. This is only needed on
980 some combinations of hardware and BIOS. The symptom, for which
981 this config is intended, is when reboot ends with a stalled/hung
984 Currently, the only fixup is for the Geode machines using
985 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
987 Say Y if you want to enable the fixup. Currently, it's safe to
988 enable this option even if you don't need it.
992 tristate "CPU microcode loading support"
996 If you say Y here, you will be able to update the microcode on
997 certain Intel and AMD processors. The Intel support is for the
998 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
999 Xeon etc. The AMD support is for families 0x10 and later. You will
1000 obviously need the actual microcode binary data itself which is not
1001 shipped with the Linux kernel.
1003 This option selects the general module only, you need to select
1004 at least one vendor specific module as well.
1006 To compile this driver as a module, choose M here: the module
1007 will be called microcode.
1009 config MICROCODE_INTEL
1010 bool "Intel microcode loading support"
1011 depends on MICROCODE
1015 This options enables microcode patch loading support for Intel
1018 For latest news and information on obtaining all the required
1019 Intel ingredients for this driver, check:
1020 <http://www.urbanmyth.org/microcode/>.
1022 config MICROCODE_AMD
1023 bool "AMD microcode loading support"
1024 depends on MICROCODE
1027 If you select this option, microcode patch loading support for AMD
1028 processors will be enabled.
1030 config MICROCODE_OLD_INTERFACE
1032 depends on MICROCODE
1035 tristate "/dev/cpu/*/msr - Model-specific register support"
1037 This device gives privileged processes access to the x86
1038 Model-Specific Registers (MSRs). It is a character device with
1039 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1040 MSR accesses are directed to a specific CPU on multi-processor
1044 tristate "/dev/cpu/*/cpuid - CPU information support"
1046 This device gives processes access to the x86 CPUID instruction to
1047 be executed on a specific processor. It is a character device
1048 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1052 prompt "High Memory Support"
1053 default HIGHMEM64G if X86_NUMAQ
1059 depends on !X86_NUMAQ
1061 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1062 However, the address space of 32-bit x86 processors is only 4
1063 Gigabytes large. That means that, if you have a large amount of
1064 physical memory, not all of it can be "permanently mapped" by the
1065 kernel. The physical memory that's not permanently mapped is called
1068 If you are compiling a kernel which will never run on a machine with
1069 more than 1 Gigabyte total physical RAM, answer "off" here (default
1070 choice and suitable for most users). This will result in a "3GB/1GB"
1071 split: 3GB are mapped so that each process sees a 3GB virtual memory
1072 space and the remaining part of the 4GB virtual memory space is used
1073 by the kernel to permanently map as much physical memory as
1076 If the machine has between 1 and 4 Gigabytes physical RAM, then
1079 If more than 4 Gigabytes is used then answer "64GB" here. This
1080 selection turns Intel PAE (Physical Address Extension) mode on.
1081 PAE implements 3-level paging on IA32 processors. PAE is fully
1082 supported by Linux, PAE mode is implemented on all recent Intel
1083 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1084 then the kernel will not boot on CPUs that don't support PAE!
1086 The actual amount of total physical memory will either be
1087 auto detected or can be forced by using a kernel command line option
1088 such as "mem=256M". (Try "man bootparam" or see the documentation of
1089 your boot loader (lilo or loadlin) about how to pass options to the
1090 kernel at boot time.)
1092 If unsure, say "off".
1096 depends on !X86_NUMAQ
1098 Select this if you have a 32-bit processor and between 1 and 4
1099 gigabytes of physical RAM.
1106 Select this if you have a 32-bit processor and more than 4
1107 gigabytes of physical RAM.
1112 depends on EXPERIMENTAL
1113 prompt "Memory split" if EXPERT
1117 Select the desired split between kernel and user memory.
1119 If the address range available to the kernel is less than the
1120 physical memory installed, the remaining memory will be available
1121 as "high memory". Accessing high memory is a little more costly
1122 than low memory, as it needs to be mapped into the kernel first.
1123 Note that increasing the kernel address space limits the range
1124 available to user programs, making the address space there
1125 tighter. Selecting anything other than the default 3G/1G split
1126 will also likely make your kernel incompatible with binary-only
1129 If you are not absolutely sure what you are doing, leave this
1133 bool "3G/1G user/kernel split"
1134 config VMSPLIT_3G_OPT
1136 bool "3G/1G user/kernel split (for full 1G low memory)"
1138 bool "2G/2G user/kernel split"
1139 config VMSPLIT_2G_OPT
1141 bool "2G/2G user/kernel split (for full 2G low memory)"
1143 bool "1G/3G user/kernel split"
1148 default 0xB0000000 if VMSPLIT_3G_OPT
1149 default 0x80000000 if VMSPLIT_2G
1150 default 0x78000000 if VMSPLIT_2G_OPT
1151 default 0x40000000 if VMSPLIT_1G
1157 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1160 bool "PAE (Physical Address Extension) Support"
1161 depends on X86_32 && !HIGHMEM4G
1163 PAE is required for NX support, and furthermore enables
1164 larger swapspace support for non-overcommit purposes. It
1165 has the cost of more pagetable lookup overhead, and also
1166 consumes more pagetable space per process.
1168 config ARCH_PHYS_ADDR_T_64BIT
1170 depends on X86_64 || X86_PAE
1172 config ARCH_DMA_ADDR_T_64BIT
1174 depends on X86_64 || HIGHMEM64G
1176 config DIRECT_GBPAGES
1177 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1181 Allow the kernel linear mapping to use 1GB pages on CPUs that
1182 support it. This can improve the kernel's performance a tiny bit by
1183 reducing TLB pressure. If in doubt, say "Y".
1185 # Common NUMA Features
1187 bool "Numa Memory Allocation and Scheduler Support"
1189 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1190 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1192 Enable NUMA (Non Uniform Memory Access) support.
1194 The kernel will try to allocate memory used by a CPU on the
1195 local memory controller of the CPU and add some more
1196 NUMA awareness to the kernel.
1198 For 64-bit this is recommended if the system is Intel Core i7
1199 (or later), AMD Opteron, or EM64T NUMA.
1201 For 32-bit this is only needed on (rare) 32-bit-only platforms
1202 that support NUMA topologies, such as NUMAQ / Summit, or if you
1203 boot a 32-bit kernel on a 64-bit NUMA platform.
1205 Otherwise, you should say N.
1207 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1208 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1212 prompt "Old style AMD Opteron NUMA detection"
1213 depends on X86_64 && NUMA && PCI
1215 Enable AMD NUMA node topology detection. You should say Y here if
1216 you have a multi processor AMD system. This uses an old method to
1217 read the NUMA configuration directly from the builtin Northbridge
1218 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1219 which also takes priority if both are compiled in.
1221 config X86_64_ACPI_NUMA
1223 prompt "ACPI NUMA detection"
1224 depends on X86_64 && NUMA && ACPI && PCI
1227 Enable ACPI SRAT based node topology detection.
1229 # Some NUMA nodes have memory ranges that span
1230 # other nodes. Even though a pfn is valid and
1231 # between a node's start and end pfns, it may not
1232 # reside on that node. See memmap_init_zone()
1234 config NODES_SPAN_OTHER_NODES
1236 depends on X86_64_ACPI_NUMA
1239 bool "NUMA emulation"
1242 Enable NUMA emulation. A flat machine will be split
1243 into virtual nodes when booted with "numa=fake=N", where N is the
1244 number of nodes. This is only useful for debugging.
1247 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1249 default "10" if MAXSMP
1250 default "6" if X86_64
1251 default "4" if X86_NUMAQ
1253 depends on NEED_MULTIPLE_NODES
1255 Specify the maximum number of NUMA Nodes available on the target
1256 system. Increases memory reserved to accommodate various tables.
1258 config HAVE_ARCH_ALLOC_REMAP
1260 depends on X86_32 && NUMA
1262 config ARCH_HAVE_MEMORY_PRESENT
1264 depends on X86_32 && DISCONTIGMEM
1266 config NEED_NODE_MEMMAP_SIZE
1268 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1270 config ARCH_FLATMEM_ENABLE
1272 depends on X86_32 && !NUMA
1274 config ARCH_DISCONTIGMEM_ENABLE
1276 depends on NUMA && X86_32
1278 config ARCH_DISCONTIGMEM_DEFAULT
1280 depends on NUMA && X86_32
1282 config ARCH_SPARSEMEM_ENABLE
1284 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1285 select SPARSEMEM_STATIC if X86_32
1286 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1288 config ARCH_SPARSEMEM_DEFAULT
1292 config ARCH_SELECT_MEMORY_MODEL
1294 depends on ARCH_SPARSEMEM_ENABLE
1296 config ARCH_MEMORY_PROBE
1298 depends on X86_64 && MEMORY_HOTPLUG
1300 config ARCH_PROC_KCORE_TEXT
1302 depends on X86_64 && PROC_KCORE
1304 config ILLEGAL_POINTER_VALUE
1307 default 0xdead000000000000 if X86_64
1312 bool "Allocate 3rd-level pagetables from highmem"
1315 The VM uses one page table entry for each page of physical memory.
1316 For systems with a lot of RAM, this can be wasteful of precious
1317 low memory. Setting this option will put user-space page table
1318 entries in high memory.
1320 config X86_CHECK_BIOS_CORRUPTION
1321 bool "Check for low memory corruption"
1323 Periodically check for memory corruption in low memory, which
1324 is suspected to be caused by BIOS. Even when enabled in the
1325 configuration, it is disabled at runtime. Enable it by
1326 setting "memory_corruption_check=1" on the kernel command
1327 line. By default it scans the low 64k of memory every 60
1328 seconds; see the memory_corruption_check_size and
1329 memory_corruption_check_period parameters in
1330 Documentation/kernel-parameters.txt to adjust this.
1332 When enabled with the default parameters, this option has
1333 almost no overhead, as it reserves a relatively small amount
1334 of memory and scans it infrequently. It both detects corruption
1335 and prevents it from affecting the running system.
1337 It is, however, intended as a diagnostic tool; if repeatable
1338 BIOS-originated corruption always affects the same memory,
1339 you can use memmap= to prevent the kernel from using that
1342 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1343 bool "Set the default setting of memory_corruption_check"
1344 depends on X86_CHECK_BIOS_CORRUPTION
1347 Set whether the default state of memory_corruption_check is
1350 config X86_RESERVE_LOW
1351 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1355 Specify the amount of low memory to reserve for the BIOS.
1357 The first page contains BIOS data structures that the kernel
1358 must not use, so that page must always be reserved.
1360 By default we reserve the first 64K of physical RAM, as a
1361 number of BIOSes are known to corrupt that memory range
1362 during events such as suspend/resume or monitor cable
1363 insertion, so it must not be used by the kernel.
1365 You can set this to 4 if you are absolutely sure that you
1366 trust the BIOS to get all its memory reservations and usages
1367 right. If you know your BIOS have problems beyond the
1368 default 64K area, you can set this to 640 to avoid using the
1369 entire low memory range.
1371 If you have doubts about the BIOS (e.g. suspend/resume does
1372 not work or there's kernel crashes after certain hardware
1373 hotplug events) then you might want to enable
1374 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1375 typical corruption patterns.
1377 Leave this to the default value of 64 if you are unsure.
1379 config MATH_EMULATION
1381 prompt "Math emulation" if X86_32
1383 Linux can emulate a math coprocessor (used for floating point
1384 operations) if you don't have one. 486DX and Pentium processors have
1385 a math coprocessor built in, 486SX and 386 do not, unless you added
1386 a 487DX or 387, respectively. (The messages during boot time can
1387 give you some hints here ["man dmesg"].) Everyone needs either a
1388 coprocessor or this emulation.
1390 If you don't have a math coprocessor, you need to say Y here; if you
1391 say Y here even though you have a coprocessor, the coprocessor will
1392 be used nevertheless. (This behavior can be changed with the kernel
1393 command line option "no387", which comes handy if your coprocessor
1394 is broken. Try "man bootparam" or see the documentation of your boot
1395 loader (lilo or loadlin) about how to pass options to the kernel at
1396 boot time.) This means that it is a good idea to say Y here if you
1397 intend to use this kernel on different machines.
1399 More information about the internals of the Linux math coprocessor
1400 emulation can be found in <file:arch/x86/math-emu/README>.
1402 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1403 kernel, it won't hurt.
1407 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1409 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1410 the Memory Type Range Registers (MTRRs) may be used to control
1411 processor access to memory ranges. This is most useful if you have
1412 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1413 allows bus write transfers to be combined into a larger transfer
1414 before bursting over the PCI/AGP bus. This can increase performance
1415 of image write operations 2.5 times or more. Saying Y here creates a
1416 /proc/mtrr file which may be used to manipulate your processor's
1417 MTRRs. Typically the X server should use this.
1419 This code has a reasonably generic interface so that similar
1420 control registers on other processors can be easily supported
1423 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1424 Registers (ARRs) which provide a similar functionality to MTRRs. For
1425 these, the ARRs are used to emulate the MTRRs.
1426 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1427 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1428 write-combining. All of these processors are supported by this code
1429 and it makes sense to say Y here if you have one of them.
1431 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1432 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1433 can lead to all sorts of problems, so it's good to say Y here.
1435 You can safely say Y even if your machine doesn't have MTRRs, you'll
1436 just add about 9 KB to your kernel.
1438 See <file:Documentation/x86/mtrr.txt> for more information.
1440 config MTRR_SANITIZER
1442 prompt "MTRR cleanup support"
1445 Convert MTRR layout from continuous to discrete, so X drivers can
1446 add writeback entries.
1448 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1449 The largest mtrr entry size for a continuous block can be set with
1454 config MTRR_SANITIZER_ENABLE_DEFAULT
1455 int "MTRR cleanup enable value (0-1)"
1458 depends on MTRR_SANITIZER
1460 Enable mtrr cleanup default value
1462 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1463 int "MTRR cleanup spare reg num (0-7)"
1466 depends on MTRR_SANITIZER
1468 mtrr cleanup spare entries default, it can be changed via
1469 mtrr_spare_reg_nr=N on the kernel command line.
1473 prompt "x86 PAT support" if EXPERT
1476 Use PAT attributes to setup page level cache control.
1478 PATs are the modern equivalents of MTRRs and are much more
1479 flexible than MTRRs.
1481 Say N here if you see bootup problems (boot crash, boot hang,
1482 spontaneous reboots) or a non-working video driver.
1486 config ARCH_USES_PG_UNCACHED
1492 prompt "x86 architectural random number generator" if EXPERT
1494 Enable the x86 architectural RDRAND instruction
1495 (Intel Bull Mountain technology) to generate random numbers.
1496 If supported, this is a high bandwidth, cryptographically
1497 secure hardware random number generator.
1501 prompt "Supervisor Mode Access Prevention" if EXPERT
1503 Supervisor Mode Access Prevention (SMAP) is a security
1504 feature in newer Intel processors. There is a small
1505 performance cost if this enabled and turned on; there is
1506 also a small increase in the kernel size if this is enabled.
1511 bool "EFI runtime service support"
1514 This enables the kernel to use EFI runtime services that are
1515 available (such as the EFI variable services).
1517 This option is only useful on systems that have EFI firmware.
1518 In addition, you should use the latest ELILO loader available
1519 at <http://elilo.sourceforge.net> in order to take advantage
1520 of EFI runtime services. However, even with this option, the
1521 resultant kernel should continue to boot on existing non-EFI
1525 bool "EFI stub support"
1528 This kernel feature allows a bzImage to be loaded directly
1529 by EFI firmware without the use of a bootloader.
1531 See Documentation/x86/efi-stub.txt for more information.
1535 prompt "Enable seccomp to safely compute untrusted bytecode"
1537 This kernel feature is useful for number crunching applications
1538 that may need to compute untrusted bytecode during their
1539 execution. By using pipes or other transports made available to
1540 the process as file descriptors supporting the read/write
1541 syscalls, it's possible to isolate those applications in
1542 their own address space using seccomp. Once seccomp is
1543 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1544 and the task is only allowed to execute a few safe syscalls
1545 defined by each seccomp mode.
1547 If unsure, say Y. Only embedded should say N here.
1549 config CC_STACKPROTECTOR
1550 bool "Enable -fstack-protector buffer overflow detection"
1552 This option turns on the -fstack-protector GCC feature. This
1553 feature puts, at the beginning of functions, a canary value on
1554 the stack just before the return address, and validates
1555 the value just before actually returning. Stack based buffer
1556 overflows (that need to overwrite this return address) now also
1557 overwrite the canary, which gets detected and the attack is then
1558 neutralized via a kernel panic.
1560 This feature requires gcc version 4.2 or above, or a distribution
1561 gcc with the feature backported. Older versions are automatically
1562 detected and for those versions, this configuration option is
1563 ignored. (and a warning is printed during bootup)
1565 source kernel/Kconfig.hz
1568 bool "kexec system call"
1570 kexec is a system call that implements the ability to shutdown your
1571 current kernel, and to start another kernel. It is like a reboot
1572 but it is independent of the system firmware. And like a reboot
1573 you can start any kernel with it, not just Linux.
1575 The name comes from the similarity to the exec system call.
1577 It is an ongoing process to be certain the hardware in a machine
1578 is properly shutdown, so do not be surprised if this code does not
1579 initially work for you. It may help to enable device hotplugging
1580 support. As of this writing the exact hardware interface is
1581 strongly in flux, so no good recommendation can be made.
1584 bool "kernel crash dumps"
1585 depends on X86_64 || (X86_32 && HIGHMEM)
1587 Generate crash dump after being started by kexec.
1588 This should be normally only set in special crash dump kernels
1589 which are loaded in the main kernel with kexec-tools into
1590 a specially reserved region and then later executed after
1591 a crash by kdump/kexec. The crash dump kernel must be compiled
1592 to a memory address not used by the main kernel or BIOS using
1593 PHYSICAL_START, or it must be built as a relocatable image
1594 (CONFIG_RELOCATABLE=y).
1595 For more details see Documentation/kdump/kdump.txt
1598 bool "kexec jump (EXPERIMENTAL)"
1599 depends on EXPERIMENTAL
1600 depends on KEXEC && HIBERNATION
1602 Jump between original kernel and kexeced kernel and invoke
1603 code in physical address mode via KEXEC
1605 config PHYSICAL_START
1606 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1609 This gives the physical address where the kernel is loaded.
1611 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1612 bzImage will decompress itself to above physical address and
1613 run from there. Otherwise, bzImage will run from the address where
1614 it has been loaded by the boot loader and will ignore above physical
1617 In normal kdump cases one does not have to set/change this option
1618 as now bzImage can be compiled as a completely relocatable image
1619 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1620 address. This option is mainly useful for the folks who don't want
1621 to use a bzImage for capturing the crash dump and want to use a
1622 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1623 to be specifically compiled to run from a specific memory area
1624 (normally a reserved region) and this option comes handy.
1626 So if you are using bzImage for capturing the crash dump,
1627 leave the value here unchanged to 0x1000000 and set
1628 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1629 for capturing the crash dump change this value to start of
1630 the reserved region. In other words, it can be set based on
1631 the "X" value as specified in the "crashkernel=YM@XM"
1632 command line boot parameter passed to the panic-ed
1633 kernel. Please take a look at Documentation/kdump/kdump.txt
1634 for more details about crash dumps.
1636 Usage of bzImage for capturing the crash dump is recommended as
1637 one does not have to build two kernels. Same kernel can be used
1638 as production kernel and capture kernel. Above option should have
1639 gone away after relocatable bzImage support is introduced. But it
1640 is present because there are users out there who continue to use
1641 vmlinux for dump capture. This option should go away down the
1644 Don't change this unless you know what you are doing.
1647 bool "Build a relocatable kernel"
1650 This builds a kernel image that retains relocation information
1651 so it can be loaded someplace besides the default 1MB.
1652 The relocations tend to make the kernel binary about 10% larger,
1653 but are discarded at runtime.
1655 One use is for the kexec on panic case where the recovery kernel
1656 must live at a different physical address than the primary
1659 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1660 it has been loaded at and the compile time physical address
1661 (CONFIG_PHYSICAL_START) is ignored.
1663 # Relocation on x86-32 needs some additional build support
1664 config X86_NEED_RELOCS
1666 depends on X86_32 && RELOCATABLE
1668 config PHYSICAL_ALIGN
1669 hex "Alignment value to which kernel should be aligned" if X86_32
1671 range 0x2000 0x1000000
1673 This value puts the alignment restrictions on physical address
1674 where kernel is loaded and run from. Kernel is compiled for an
1675 address which meets above alignment restriction.
1677 If bootloader loads the kernel at a non-aligned address and
1678 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1679 address aligned to above value and run from there.
1681 If bootloader loads the kernel at a non-aligned address and
1682 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1683 load address and decompress itself to the address it has been
1684 compiled for and run from there. The address for which kernel is
1685 compiled already meets above alignment restrictions. Hence the
1686 end result is that kernel runs from a physical address meeting
1687 above alignment restrictions.
1689 Don't change this unless you know what you are doing.
1692 bool "Support for hot-pluggable CPUs"
1693 depends on SMP && HOTPLUG
1695 Say Y here to allow turning CPUs off and on. CPUs can be
1696 controlled through /sys/devices/system/cpu.
1697 ( Note: power management support will enable this option
1698 automatically on SMP systems. )
1699 Say N if you want to disable CPU hotplug.
1701 config BOOTPARAM_HOTPLUG_CPU0
1702 bool "Set default setting of cpu0_hotpluggable"
1704 depends on HOTPLUG_CPU && EXPERIMENTAL
1706 Set whether default state of cpu0_hotpluggable is on or off.
1708 Say Y here to enable CPU0 hotplug by default. If this switch
1709 is turned on, there is no need to give cpu0_hotplug kernel
1710 parameter and the CPU0 hotplug feature is enabled by default.
1712 Please note: there are two known CPU0 dependencies if you want
1713 to enable the CPU0 hotplug feature either by this switch or by
1714 cpu0_hotplug kernel parameter.
1716 First, resume from hibernate or suspend always starts from CPU0.
1717 So hibernate and suspend are prevented if CPU0 is offline.
1719 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1720 offline if any interrupt can not migrate out of CPU0. There may
1721 be other CPU0 dependencies.
1723 Please make sure the dependencies are under your control before
1724 you enable this feature.
1726 Say N if you don't want to enable CPU0 hotplug feature by default.
1727 You still can enable the CPU0 hotplug feature at boot by kernel
1728 parameter cpu0_hotplug.
1730 config DEBUG_HOTPLUG_CPU0
1732 prompt "Debug CPU0 hotplug"
1733 depends on HOTPLUG_CPU && EXPERIMENTAL
1735 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1736 soon as possible and boots up userspace with CPU0 offlined. User
1737 can online CPU0 back after boot time.
1739 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1740 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1741 compilation or giving cpu0_hotplug kernel parameter at boot.
1747 prompt "Compat VDSO support"
1748 depends on X86_32 || IA32_EMULATION
1750 Map the 32-bit VDSO to the predictable old-style address too.
1752 Say N here if you are running a sufficiently recent glibc
1753 version (2.3.3 or later), to remove the high-mapped
1754 VDSO mapping and to exclusively use the randomized VDSO.
1759 bool "Built-in kernel command line"
1761 Allow for specifying boot arguments to the kernel at
1762 build time. On some systems (e.g. embedded ones), it is
1763 necessary or convenient to provide some or all of the
1764 kernel boot arguments with the kernel itself (that is,
1765 to not rely on the boot loader to provide them.)
1767 To compile command line arguments into the kernel,
1768 set this option to 'Y', then fill in the
1769 the boot arguments in CONFIG_CMDLINE.
1771 Systems with fully functional boot loaders (i.e. non-embedded)
1772 should leave this option set to 'N'.
1775 string "Built-in kernel command string"
1776 depends on CMDLINE_BOOL
1779 Enter arguments here that should be compiled into the kernel
1780 image and used at boot time. If the boot loader provides a
1781 command line at boot time, it is appended to this string to
1782 form the full kernel command line, when the system boots.
1784 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1785 change this behavior.
1787 In most cases, the command line (whether built-in or provided
1788 by the boot loader) should specify the device for the root
1791 config CMDLINE_OVERRIDE
1792 bool "Built-in command line overrides boot loader arguments"
1793 depends on CMDLINE_BOOL
1795 Set this option to 'Y' to have the kernel ignore the boot loader
1796 command line, and use ONLY the built-in command line.
1798 This is used to work around broken boot loaders. This should
1799 be set to 'N' under normal conditions.
1803 config ARCH_ENABLE_MEMORY_HOTPLUG
1805 depends on X86_64 || (X86_32 && HIGHMEM)
1807 config ARCH_ENABLE_MEMORY_HOTREMOVE
1809 depends on MEMORY_HOTPLUG
1811 config USE_PERCPU_NUMA_NODE_ID
1815 menu "Power management and ACPI options"
1817 config ARCH_HIBERNATION_HEADER
1819 depends on X86_64 && HIBERNATION
1821 source "kernel/power/Kconfig"
1823 source "drivers/acpi/Kconfig"
1825 source "drivers/sfi/Kconfig"
1832 tristate "APM (Advanced Power Management) BIOS support"
1833 depends on X86_32 && PM_SLEEP
1835 APM is a BIOS specification for saving power using several different
1836 techniques. This is mostly useful for battery powered laptops with
1837 APM compliant BIOSes. If you say Y here, the system time will be
1838 reset after a RESUME operation, the /proc/apm device will provide
1839 battery status information, and user-space programs will receive
1840 notification of APM "events" (e.g. battery status change).
1842 If you select "Y" here, you can disable actual use of the APM
1843 BIOS by passing the "apm=off" option to the kernel at boot time.
1845 Note that the APM support is almost completely disabled for
1846 machines with more than one CPU.
1848 In order to use APM, you will need supporting software. For location
1849 and more information, read <file:Documentation/power/apm-acpi.txt>
1850 and the Battery Powered Linux mini-HOWTO, available from
1851 <http://www.tldp.org/docs.html#howto>.
1853 This driver does not spin down disk drives (see the hdparm(8)
1854 manpage ("man 8 hdparm") for that), and it doesn't turn off
1855 VESA-compliant "green" monitors.
1857 This driver does not support the TI 4000M TravelMate and the ACER
1858 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1859 desktop machines also don't have compliant BIOSes, and this driver
1860 may cause those machines to panic during the boot phase.
1862 Generally, if you don't have a battery in your machine, there isn't
1863 much point in using this driver and you should say N. If you get
1864 random kernel OOPSes or reboots that don't seem to be related to
1865 anything, try disabling/enabling this option (or disabling/enabling
1868 Some other things you should try when experiencing seemingly random,
1871 1) make sure that you have enough swap space and that it is
1873 2) pass the "no-hlt" option to the kernel
1874 3) switch on floating point emulation in the kernel and pass
1875 the "no387" option to the kernel
1876 4) pass the "floppy=nodma" option to the kernel
1877 5) pass the "mem=4M" option to the kernel (thereby disabling
1878 all but the first 4 MB of RAM)
1879 6) make sure that the CPU is not over clocked.
1880 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1881 8) disable the cache from your BIOS settings
1882 9) install a fan for the video card or exchange video RAM
1883 10) install a better fan for the CPU
1884 11) exchange RAM chips
1885 12) exchange the motherboard.
1887 To compile this driver as a module, choose M here: the
1888 module will be called apm.
1892 config APM_IGNORE_USER_SUSPEND
1893 bool "Ignore USER SUSPEND"
1895 This option will ignore USER SUSPEND requests. On machines with a
1896 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1897 series notebooks, it is necessary to say Y because of a BIOS bug.
1899 config APM_DO_ENABLE
1900 bool "Enable PM at boot time"
1902 Enable APM features at boot time. From page 36 of the APM BIOS
1903 specification: "When disabled, the APM BIOS does not automatically
1904 power manage devices, enter the Standby State, enter the Suspend
1905 State, or take power saving steps in response to CPU Idle calls."
1906 This driver will make CPU Idle calls when Linux is idle (unless this
1907 feature is turned off -- see "Do CPU IDLE calls", below). This
1908 should always save battery power, but more complicated APM features
1909 will be dependent on your BIOS implementation. You may need to turn
1910 this option off if your computer hangs at boot time when using APM
1911 support, or if it beeps continuously instead of suspending. Turn
1912 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1913 T400CDT. This is off by default since most machines do fine without
1917 bool "Make CPU Idle calls when idle"
1919 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1920 On some machines, this can activate improved power savings, such as
1921 a slowed CPU clock rate, when the machine is idle. These idle calls
1922 are made after the idle loop has run for some length of time (e.g.,
1923 333 mS). On some machines, this will cause a hang at boot time or
1924 whenever the CPU becomes idle. (On machines with more than one CPU,
1925 this option does nothing.)
1927 config APM_DISPLAY_BLANK
1928 bool "Enable console blanking using APM"
1930 Enable console blanking using the APM. Some laptops can use this to
1931 turn off the LCD backlight when the screen blanker of the Linux
1932 virtual console blanks the screen. Note that this is only used by
1933 the virtual console screen blanker, and won't turn off the backlight
1934 when using the X Window system. This also doesn't have anything to
1935 do with your VESA-compliant power-saving monitor. Further, this
1936 option doesn't work for all laptops -- it might not turn off your
1937 backlight at all, or it might print a lot of errors to the console,
1938 especially if you are using gpm.
1940 config APM_ALLOW_INTS
1941 bool "Allow interrupts during APM BIOS calls"
1943 Normally we disable external interrupts while we are making calls to
1944 the APM BIOS as a measure to lessen the effects of a badly behaving
1945 BIOS implementation. The BIOS should reenable interrupts if it
1946 needs to. Unfortunately, some BIOSes do not -- especially those in
1947 many of the newer IBM Thinkpads. If you experience hangs when you
1948 suspend, try setting this to Y. Otherwise, say N.
1952 source "drivers/cpufreq/Kconfig"
1954 source "drivers/cpuidle/Kconfig"
1956 source "drivers/idle/Kconfig"
1961 menu "Bus options (PCI etc.)"
1966 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1968 Find out whether you have a PCI motherboard. PCI is the name of a
1969 bus system, i.e. the way the CPU talks to the other stuff inside
1970 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1971 VESA. If you have PCI, say Y, otherwise N.
1974 prompt "PCI access mode"
1975 depends on X86_32 && PCI
1978 On PCI systems, the BIOS can be used to detect the PCI devices and
1979 determine their configuration. However, some old PCI motherboards
1980 have BIOS bugs and may crash if this is done. Also, some embedded
1981 PCI-based systems don't have any BIOS at all. Linux can also try to
1982 detect the PCI hardware directly without using the BIOS.
1984 With this option, you can specify how Linux should detect the
1985 PCI devices. If you choose "BIOS", the BIOS will be used,
1986 if you choose "Direct", the BIOS won't be used, and if you
1987 choose "MMConfig", then PCI Express MMCONFIG will be used.
1988 If you choose "Any", the kernel will try MMCONFIG, then the
1989 direct access method and falls back to the BIOS if that doesn't
1990 work. If unsure, go with the default, which is "Any".
1995 config PCI_GOMMCONFIG
2012 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2014 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2017 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2021 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2025 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2029 depends on PCI && XEN
2037 bool "Support mmconfig PCI config space access"
2038 depends on X86_64 && PCI && ACPI
2040 config PCI_CNB20LE_QUIRK
2041 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2042 depends on PCI && EXPERIMENTAL
2044 Read the PCI windows out of the CNB20LE host bridge. This allows
2045 PCI hotplug to work on systems with the CNB20LE chipset which do
2048 There's no public spec for this chipset, and this functionality
2049 is known to be incomplete.
2051 You should say N unless you know you need this.
2053 source "drivers/pci/pcie/Kconfig"
2055 source "drivers/pci/Kconfig"
2057 # x86_64 have no ISA slots, but can have ISA-style DMA.
2059 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2062 Enables ISA-style DMA support for devices requiring such controllers.
2070 Find out whether you have ISA slots on your motherboard. ISA is the
2071 name of a bus system, i.e. the way the CPU talks to the other stuff
2072 inside your box. Other bus systems are PCI, EISA, MicroChannel
2073 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2074 newer boards don't support it. If you have ISA, say Y, otherwise N.
2080 The Extended Industry Standard Architecture (EISA) bus was
2081 developed as an open alternative to the IBM MicroChannel bus.
2083 The EISA bus provided some of the features of the IBM MicroChannel
2084 bus while maintaining backward compatibility with cards made for
2085 the older ISA bus. The EISA bus saw limited use between 1988 and
2086 1995 when it was made obsolete by the PCI bus.
2088 Say Y here if you are building a kernel for an EISA-based machine.
2092 source "drivers/eisa/Kconfig"
2095 tristate "NatSemi SCx200 support"
2097 This provides basic support for National Semiconductor's
2098 (now AMD's) Geode processors. The driver probes for the
2099 PCI-IDs of several on-chip devices, so its a good dependency
2100 for other scx200_* drivers.
2102 If compiled as a module, the driver is named scx200.
2104 config SCx200HR_TIMER
2105 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2109 This driver provides a clocksource built upon the on-chip
2110 27MHz high-resolution timer. Its also a workaround for
2111 NSC Geode SC-1100's buggy TSC, which loses time when the
2112 processor goes idle (as is done by the scheduler). The
2113 other workaround is idle=poll boot option.
2116 bool "One Laptop Per Child support"
2123 Add support for detecting the unique features of the OLPC
2127 bool "OLPC XO-1 Power Management"
2128 depends on OLPC && MFD_CS5535 && PM_SLEEP
2131 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2134 bool "OLPC XO-1 Real Time Clock"
2135 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2137 Add support for the XO-1 real time clock, which can be used as a
2138 programmable wakeup source.
2141 bool "OLPC XO-1 SCI extras"
2142 depends on OLPC && OLPC_XO1_PM
2148 Add support for SCI-based features of the OLPC XO-1 laptop:
2149 - EC-driven system wakeups
2153 - AC adapter status updates
2154 - Battery status updates
2156 config OLPC_XO15_SCI
2157 bool "OLPC XO-1.5 SCI extras"
2158 depends on OLPC && ACPI
2161 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2162 - EC-driven system wakeups
2163 - AC adapter status updates
2164 - Battery status updates
2167 bool "PCEngines ALIX System Support (LED setup)"
2170 This option enables system support for the PCEngines ALIX.
2171 At present this just sets up LEDs for GPIO control on
2172 ALIX2/3/6 boards. However, other system specific setup should
2175 Note: You must still enable the drivers for GPIO and LED support
2176 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2178 Note: You have to set alix.force=1 for boards with Award BIOS.
2181 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2184 This option enables system support for the Soekris Engineering net5501.
2187 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2191 This option enables system support for the Traverse Technologies GEOS.
2197 depends on CPU_SUP_AMD && PCI
2199 source "drivers/pcmcia/Kconfig"
2201 source "drivers/pci/hotplug/Kconfig"
2204 bool "RapidIO support"
2208 If you say Y here, the kernel will include drivers and
2209 infrastructure code to support RapidIO interconnect devices.
2211 source "drivers/rapidio/Kconfig"
2216 menu "Executable file formats / Emulations"
2218 source "fs/Kconfig.binfmt"
2220 config IA32_EMULATION
2221 bool "IA32 Emulation"
2223 select COMPAT_BINFMT_ELF
2226 Include code to run legacy 32-bit programs under a
2227 64-bit kernel. You should likely turn this on, unless you're
2228 100% sure that you don't have any 32-bit programs left.
2231 tristate "IA32 a.out support"
2232 depends on IA32_EMULATION
2234 Support old a.out binaries in the 32bit emulation.
2237 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2238 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2240 Include code to run binaries for the x32 native 32-bit ABI
2241 for 64-bit processors. An x32 process gets access to the
2242 full 64-bit register file and wide data path while leaving
2243 pointers at 32 bits for smaller memory footprint.
2245 You will need a recent binutils (2.22 or later) with
2246 elf32_x86_64 support enabled to compile a kernel with this
2251 depends on IA32_EMULATION || X86_X32
2252 select ARCH_WANT_OLD_COMPAT_IPC
2255 config COMPAT_FOR_U64_ALIGNMENT
2258 config SYSVIPC_COMPAT
2270 config HAVE_ATOMIC_IOMAP
2274 config HAVE_TEXT_POKE_SMP
2276 select STOP_MACHINE if SMP
2278 config X86_DEV_DMA_OPS
2280 depends on X86_64 || STA2X11
2282 config X86_DMA_REMAP
2286 source "net/Kconfig"
2288 source "drivers/Kconfig"
2290 source "drivers/firmware/Kconfig"
2294 source "arch/x86/Kconfig.debug"
2296 source "security/Kconfig"
2298 source "crypto/Kconfig"
2300 source "arch/x86/kvm/Kconfig"
2302 source "lib/Kconfig"
projects / ~andy / linux / blob