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
32 select HAVE_IOREMAP_PROT
35 select HAVE_MEMBLOCK_NODE_MAP
36 select ARCH_DISCARD_MEMBLOCK
37 select ARCH_WANT_OPTIONAL_GPIOLIB
38 select ARCH_WANT_FRAME_POINTERS
40 select HAVE_DMA_CONTIGUOUS if !SWIOTLB
41 select HAVE_KRETPROBES
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_FUNCTION_TRACER
48 select HAVE_FUNCTION_GRAPH_TRACER
49 select HAVE_FUNCTION_GRAPH_FP_TEST
50 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
51 select HAVE_SYSCALL_TRACEPOINTS
52 select SYSCTL_EXCEPTION_TRACE
55 select HAVE_ARCH_TRACEHOOK
56 select HAVE_GENERIC_DMA_COHERENT if X86_32
57 select HAVE_EFFICIENT_UNALIGNED_ACCESS
58 select USER_STACKTRACE_SUPPORT
59 select HAVE_REGS_AND_STACK_ACCESS_API
60 select HAVE_DMA_API_DEBUG
61 select HAVE_KERNEL_GZIP
62 select HAVE_KERNEL_BZIP2
63 select HAVE_KERNEL_LZMA
65 select HAVE_KERNEL_LZO
66 select HAVE_HW_BREAKPOINT
67 select HAVE_MIXED_BREAKPOINTS_REGS
69 select HAVE_PERF_EVENTS_NMI
71 select HAVE_PERF_USER_STACK_DUMP
72 select HAVE_DEBUG_KMEMLEAK
74 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
75 select HAVE_CMPXCHG_LOCAL
76 select HAVE_CMPXCHG_DOUBLE
77 select HAVE_ARCH_KMEMCHECK
78 select HAVE_USER_RETURN_NOTIFIER
79 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
80 select HAVE_ARCH_JUMP_LABEL
81 select HAVE_TEXT_POKE_SMP
82 select HAVE_GENERIC_HARDIRQS
83 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
85 select GENERIC_FIND_FIRST_BIT
86 select GENERIC_IRQ_PROBE
87 select GENERIC_PENDING_IRQ if SMP
88 select GENERIC_IRQ_SHOW
89 select GENERIC_CLOCKEVENTS_MIN_ADJUST
90 select IRQ_FORCED_THREADING
91 select USE_GENERIC_SMP_HELPERS if SMP
92 select HAVE_BPF_JIT if X86_64
93 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
95 select ARCH_HAVE_NMI_SAFE_CMPXCHG
97 select DCACHE_WORD_ACCESS
98 select GENERIC_SMP_IDLE_THREAD
99 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
100 select HAVE_ARCH_SECCOMP_FILTER
101 select BUILDTIME_EXTABLE_SORT
102 select GENERIC_CMOS_UPDATE
103 select CLOCKSOURCE_WATCHDOG
104 select GENERIC_CLOCKEVENTS
105 select ARCH_CLOCKSOURCE_DATA if X86_64
106 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
107 select GENERIC_TIME_VSYSCALL if X86_64
108 select KTIME_SCALAR if X86_32
109 select GENERIC_STRNCPY_FROM_USER
110 select GENERIC_STRNLEN_USER
111 select HAVE_CONTEXT_TRACKING if X86_64
112 select HAVE_IRQ_TIME_ACCOUNTING
113 select MODULES_USE_ELF_REL if X86_32
114 select MODULES_USE_ELF_RELA if X86_64
115 select CLONE_BACKWARDS if X86_32
116 select GENERIC_SIGALTSTACK
118 config INSTRUCTION_DECODER
120 depends on KPROBES || PERF_EVENTS || UPROBES
124 default "elf32-i386" if X86_32
125 default "elf64-x86-64" if X86_64
127 config ARCH_DEFCONFIG
129 default "arch/x86/configs/i386_defconfig" if X86_32
130 default "arch/x86/configs/x86_64_defconfig" if X86_64
132 config LOCKDEP_SUPPORT
135 config STACKTRACE_SUPPORT
138 config HAVE_LATENCYTOP_SUPPORT
147 config NEED_DMA_MAP_STATE
149 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
151 config NEED_SG_DMA_LENGTH
154 config GENERIC_ISA_DMA
156 depends on ISA_DMA_API
161 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
163 config GENERIC_BUG_RELATIVE_POINTERS
166 config GENERIC_HWEIGHT
172 config ARCH_MAY_HAVE_PC_FDC
174 depends on ISA_DMA_API
176 config RWSEM_XCHGADD_ALGORITHM
179 config GENERIC_CALIBRATE_DELAY
182 config ARCH_HAS_CPU_RELAX
185 config ARCH_HAS_DEFAULT_IDLE
188 config ARCH_HAS_CACHE_LINE_SIZE
191 config ARCH_HAS_CPU_AUTOPROBE
194 config HAVE_SETUP_PER_CPU_AREA
197 config NEED_PER_CPU_EMBED_FIRST_CHUNK
200 config NEED_PER_CPU_PAGE_FIRST_CHUNK
203 config ARCH_HIBERNATION_POSSIBLE
206 config ARCH_SUSPEND_POSSIBLE
217 config ARCH_SUPPORTS_OPTIMIZED_INLINING
220 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
223 config HAVE_INTEL_TXT
225 depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
229 depends on X86_32 && SMP
233 depends on X86_64 && SMP
239 config X86_32_LAZY_GS
241 depends on X86_32 && !CC_STACKPROTECTOR
243 config ARCH_HWEIGHT_CFLAGS
245 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
246 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
248 config ARCH_CPU_PROBE_RELEASE
250 depends on HOTPLUG_CPU
252 config ARCH_SUPPORTS_UPROBES
255 source "init/Kconfig"
256 source "kernel/Kconfig.freezer"
258 menu "Processor type and features"
261 bool "DMA memory allocation support" if EXPERT
264 DMA memory allocation support allows devices with less than 32-bit
265 addressing to allocate within the first 16MB of address space.
266 Disable if no such devices will be used.
271 bool "Symmetric multi-processing support"
273 This enables support for systems with more than one CPU. If you have
274 a system with only one CPU, like most personal computers, say N. If
275 you have a system with more than one CPU, say Y.
277 If you say N here, the kernel will run on single and multiprocessor
278 machines, but will use only one CPU of a multiprocessor machine. If
279 you say Y here, the kernel will run on many, but not all,
280 singleprocessor machines. On a singleprocessor machine, the kernel
281 will run faster if you say N here.
283 Note that if you say Y here and choose architecture "586" or
284 "Pentium" under "Processor family", the kernel will not work on 486
285 architectures. Similarly, multiprocessor kernels for the "PPro"
286 architecture may not work on all Pentium based boards.
288 People using multiprocessor machines who say Y here should also say
289 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
290 Management" code will be disabled if you say Y here.
292 See also <file:Documentation/x86/i386/IO-APIC.txt>,
293 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
294 <http://www.tldp.org/docs.html#howto>.
296 If you don't know what to do here, say N.
299 bool "Support x2apic"
300 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
302 This enables x2apic support on CPUs that have this feature.
304 This allows 32-bit apic IDs (so it can support very large systems),
305 and accesses the local apic via MSRs not via mmio.
307 If you don't know what to do here, say N.
310 bool "Enable MPS table" if ACPI || SFI
312 depends on X86_LOCAL_APIC
314 For old smp systems that do not have proper acpi support. Newer systems
315 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
318 bool "Support for big SMP systems with more than 8 CPUs"
319 depends on X86_32 && SMP
321 This option is needed for the systems that have more than 8 CPUs
324 config X86_EXTENDED_PLATFORM
325 bool "Support for extended (non-PC) x86 platforms"
328 If you disable this option then the kernel will only support
329 standard PC platforms. (which covers the vast majority of
332 If you enable this option then you'll be able to select support
333 for the following (non-PC) 32 bit x86 platforms:
337 SGI 320/540 (Visual Workstation)
338 STA2X11-based (e.g. Northville)
339 Summit/EXA (IBM x440)
340 Unisys ES7000 IA32 series
341 Moorestown MID devices
343 If you have one of these systems, or if you want to build a
344 generic distribution kernel, say Y here - otherwise say N.
348 config X86_EXTENDED_PLATFORM
349 bool "Support for extended (non-PC) x86 platforms"
352 If you disable this option then the kernel will only support
353 standard PC platforms. (which covers the vast majority of
356 If you enable this option then you'll be able to select support
357 for the following (non-PC) 64 bit x86 platforms:
362 If you have one of these systems, or if you want to build a
363 generic distribution kernel, say Y here - otherwise say N.
365 # This is an alphabetically sorted list of 64 bit extended platforms
366 # Please maintain the alphabetic order if and when there are additions
368 bool "Numascale NumaChip"
370 depends on X86_EXTENDED_PLATFORM
373 depends on X86_X2APIC
374 depends on PCI_MMCONFIG
376 Adds support for Numascale NumaChip large-SMP systems. Needed to
377 enable more than ~168 cores.
378 If you don't have one of these, you should say N here.
382 select PARAVIRT_GUEST
384 depends on X86_64 && PCI
385 depends on X86_EXTENDED_PLATFORM
388 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
389 supposed to run on these EM64T-based machines. Only choose this option
390 if you have one of these machines.
393 bool "SGI Ultraviolet"
395 depends on X86_EXTENDED_PLATFORM
397 depends on X86_X2APIC
399 This option is needed in order to support SGI Ultraviolet systems.
400 If you don't have one of these, you should say N here.
402 # Following is an alphabetically sorted list of 32 bit extended platforms
403 # Please maintain the alphabetic order if and when there are additions
406 bool "CE4100 TV platform"
408 depends on PCI_GODIRECT
410 depends on X86_EXTENDED_PLATFORM
411 select X86_REBOOTFIXUPS
413 select OF_EARLY_FLATTREE
416 Select for the Intel CE media processor (CE4100) SOC.
417 This option compiles in support for the CE4100 SOC for settop
418 boxes and media devices.
420 config X86_WANT_INTEL_MID
421 bool "Intel MID platform support"
423 depends on X86_EXTENDED_PLATFORM
425 Select to build a kernel capable of supporting Intel MID platform
426 systems which do not have the PCI legacy interfaces (Moorestown,
427 Medfield). If you are building for a PC class system say N here.
429 if X86_WANT_INTEL_MID
435 bool "Medfield MID platform"
438 depends on X86_IO_APIC
446 select X86_PLATFORM_DEVICES
447 select MFD_INTEL_MSIC
449 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin
450 Internet Device(MID) platform.
451 Unlike standard x86 PCs, Medfield does not have many legacy devices
452 nor standard legacy replacement devices/features. e.g. Medfield does
453 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
458 bool "RDC R-321x SoC"
460 depends on X86_EXTENDED_PLATFORM
462 select X86_REBOOTFIXUPS
464 This option is needed for RDC R-321x system-on-chip, also known
466 If you don't have one of these chips, you should say N here.
468 config X86_32_NON_STANDARD
469 bool "Support non-standard 32-bit SMP architectures"
470 depends on X86_32 && SMP
471 depends on X86_EXTENDED_PLATFORM
473 This option compiles in the NUMAQ, Summit, bigsmp, ES7000,
474 STA2X11, default subarchitectures. It is intended for a generic
475 binary kernel. If you select them all, kernel will probe it
476 one by one and will fallback to default.
478 # Alphabetically sorted list of Non standard 32 bit platforms
481 bool "NUMAQ (IBM/Sequent)"
482 depends on X86_32_NON_STANDARD
487 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
488 NUMA multiquad box. This changes the way that processors are
489 bootstrapped, and uses Clustered Logical APIC addressing mode instead
490 of Flat Logical. You will need a new lynxer.elf file to flash your
491 firmware with - send email to <Martin.Bligh@us.ibm.com>.
493 config X86_SUPPORTS_MEMORY_FAILURE
495 # MCE code calls memory_failure():
497 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
498 depends on !X86_NUMAQ
499 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
500 depends on X86_64 || !SPARSEMEM
501 select ARCH_SUPPORTS_MEMORY_FAILURE
504 bool "SGI 320/540 (Visual Workstation)"
505 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
506 depends on X86_32_NON_STANDARD
508 The SGI Visual Workstation series is an IA32-based workstation
509 based on SGI systems chips with some legacy PC hardware attached.
511 Say Y here to create a kernel to run on the SGI 320 or 540.
513 A kernel compiled for the Visual Workstation will run on general
514 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
517 bool "STA2X11 Companion Chip Support"
518 depends on X86_32_NON_STANDARD && PCI
519 select X86_DEV_DMA_OPS
523 select ARCH_REQUIRE_GPIOLIB
526 This adds support for boards based on the STA2X11 IO-Hub,
527 a.k.a. "ConneXt". The chip is used in place of the standard
528 PC chipset, so all "standard" peripherals are missing. If this
529 option is selected the kernel will still be able to boot on
530 standard PC machines.
533 bool "Summit/EXA (IBM x440)"
534 depends on X86_32_NON_STANDARD
536 This option is needed for IBM systems that use the Summit/EXA chipset.
537 In particular, it is needed for the x440.
540 bool "Unisys ES7000 IA32 series"
541 depends on X86_32_NON_STANDARD && X86_BIGSMP
543 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
544 supposed to run on an IA32-based Unisys ES7000 system.
547 tristate "Eurobraille/Iris poweroff module"
550 The Iris machines from EuroBraille do not have APM or ACPI support
551 to shut themselves down properly. A special I/O sequence is
552 needed to do so, which is what this module does at
555 This is only for Iris machines from EuroBraille.
559 config SCHED_OMIT_FRAME_POINTER
561 prompt "Single-depth WCHAN output"
564 Calculate simpler /proc/<PID>/wchan values. If this option
565 is disabled then wchan values will recurse back to the
566 caller function. This provides more accurate wchan values,
567 at the expense of slightly more scheduling overhead.
569 If in doubt, say "Y".
571 menuconfig PARAVIRT_GUEST
572 bool "Paravirtualized guest support"
574 Say Y here to get to see options related to running Linux under
575 various hypervisors. This option alone does not add any kernel code.
577 If you say N, all options in this submenu will be skipped and disabled.
581 config PARAVIRT_TIME_ACCOUNTING
582 bool "Paravirtual steal time accounting"
586 Select this option to enable fine granularity task steal time
587 accounting. Time spent executing other tasks in parallel with
588 the current vCPU is discounted from the vCPU power. To account for
589 that, there can be a small performance impact.
591 If in doubt, say N here.
593 source "arch/x86/xen/Kconfig"
596 bool "KVM Guest support (including kvmclock)"
599 select PARAVIRT_CLOCK
600 default y if PARAVIRT_GUEST
602 This option enables various optimizations for running under the KVM
603 hypervisor. It includes a paravirtualized clock, so that instead
604 of relying on a PIT (or probably other) emulation by the
605 underlying device model, the host provides the guest with
606 timing infrastructure such as time of day, and system time
608 source "arch/x86/lguest/Kconfig"
611 bool "Enable paravirtualization code"
613 This changes the kernel so it can modify itself when it is run
614 under a hypervisor, potentially improving performance significantly
615 over full virtualization. However, when run without a hypervisor
616 the kernel is theoretically slower and slightly larger.
618 config PARAVIRT_SPINLOCKS
619 bool "Paravirtualization layer for spinlocks"
620 depends on PARAVIRT && SMP && EXPERIMENTAL
622 Paravirtualized spinlocks allow a pvops backend to replace the
623 spinlock implementation with something virtualization-friendly
624 (for example, block the virtual CPU rather than spinning).
626 Unfortunately the downside is an up to 5% performance hit on
627 native kernels, with various workloads.
629 If you are unsure how to answer this question, answer N.
631 config PARAVIRT_CLOCK
636 config PARAVIRT_DEBUG
637 bool "paravirt-ops debugging"
638 depends on PARAVIRT && DEBUG_KERNEL
640 Enable to debug paravirt_ops internals. Specifically, BUG if
641 a paravirt_op is missing when it is called.
649 This option adds a kernel parameter 'memtest', which allows memtest
651 memtest=0, mean disabled; -- default
652 memtest=1, mean do 1 test pattern;
654 memtest=4, mean do 4 test patterns.
655 If you are unsure how to answer this question, answer N.
657 config X86_SUMMIT_NUMA
659 depends on X86_32 && NUMA && X86_32_NON_STANDARD
661 config X86_CYCLONE_TIMER
663 depends on X86_SUMMIT
665 source "arch/x86/Kconfig.cpu"
669 prompt "HPET Timer Support" if X86_32
671 Use the IA-PC HPET (High Precision Event Timer) to manage
672 time in preference to the PIT and RTC, if a HPET is
674 HPET is the next generation timer replacing legacy 8254s.
675 The HPET provides a stable time base on SMP
676 systems, unlike the TSC, but it is more expensive to access,
677 as it is off-chip. You can find the HPET spec at
678 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
680 You can safely choose Y here. However, HPET will only be
681 activated if the platform and the BIOS support this feature.
682 Otherwise the 8254 will be used for timing services.
684 Choose N to continue using the legacy 8254 timer.
686 config HPET_EMULATE_RTC
688 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
691 def_bool y if X86_INTEL_MID
692 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
694 depends on X86_INTEL_MID && SFI
696 APB timer is the replacement for 8254, HPET on X86 MID platforms.
697 The APBT provides a stable time base on SMP
698 systems, unlike the TSC, but it is more expensive to access,
699 as it is off-chip. APB timers are always running regardless of CPU
700 C states, they are used as per CPU clockevent device when possible.
702 # Mark as expert because too many people got it wrong.
703 # The code disables itself when not needed.
706 bool "Enable DMI scanning" if EXPERT
708 Enabled scanning of DMI to identify machine quirks. Say Y
709 here unless you have verified that your setup is not
710 affected by entries in the DMI blacklist. Required by PNP
714 bool "GART IOMMU support" if EXPERT
717 depends on X86_64 && PCI && AMD_NB
719 Support for full DMA access of devices with 32bit memory access only
720 on systems with more than 3GB. This is usually needed for USB,
721 sound, many IDE/SATA chipsets and some other devices.
722 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
723 based hardware IOMMU and a software bounce buffer based IOMMU used
724 on Intel systems and as fallback.
725 The code is only active when needed (enough memory and limited
726 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
730 bool "IBM Calgary IOMMU support"
732 depends on X86_64 && PCI && EXPERIMENTAL
734 Support for hardware IOMMUs in IBM's xSeries x366 and x460
735 systems. Needed to run systems with more than 3GB of memory
736 properly with 32-bit PCI devices that do not support DAC
737 (Double Address Cycle). Calgary also supports bus level
738 isolation, where all DMAs pass through the IOMMU. This
739 prevents them from going anywhere except their intended
740 destination. This catches hard-to-find kernel bugs and
741 mis-behaving drivers and devices that do not use the DMA-API
742 properly to set up their DMA buffers. The IOMMU can be
743 turned off at boot time with the iommu=off parameter.
744 Normally the kernel will make the right choice by itself.
747 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
749 prompt "Should Calgary be enabled by default?"
750 depends on CALGARY_IOMMU
752 Should Calgary be enabled by default? if you choose 'y', Calgary
753 will be used (if it exists). If you choose 'n', Calgary will not be
754 used even if it exists. If you choose 'n' and would like to use
755 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
758 # need this always selected by IOMMU for the VIA workaround
762 Support for software bounce buffers used on x86-64 systems
763 which don't have a hardware IOMMU. Using this PCI devices
764 which can only access 32-bits of memory can be used on systems
765 with more than 3 GB of memory.
770 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
773 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
774 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
775 select CPUMASK_OFFSTACK
777 Enable maximum number of CPUS and NUMA Nodes for this architecture.
781 int "Maximum number of CPUs" if SMP && !MAXSMP
782 range 2 8 if SMP && X86_32 && !X86_BIGSMP
783 range 2 512 if SMP && !MAXSMP
785 default "4096" if MAXSMP
786 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
789 This allows you to specify the maximum number of CPUs which this
790 kernel will support. The maximum supported value is 512 and the
791 minimum value which makes sense is 2.
793 This is purely to save memory - each supported CPU adds
794 approximately eight kilobytes to the kernel image.
797 bool "SMT (Hyperthreading) scheduler support"
800 SMT scheduler support improves the CPU scheduler's decision making
801 when dealing with Intel Pentium 4 chips with HyperThreading at a
802 cost of slightly increased overhead in some places. If unsure say
807 prompt "Multi-core scheduler support"
810 Multi-core scheduler support improves the CPU scheduler's decision
811 making when dealing with multi-core CPU chips at a cost of slightly
812 increased overhead in some places. If unsure say N here.
814 source "kernel/Kconfig.preempt"
817 bool "Local APIC support on uniprocessors"
818 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
820 A local APIC (Advanced Programmable Interrupt Controller) is an
821 integrated interrupt controller in the CPU. If you have a single-CPU
822 system which has a processor with a local APIC, you can say Y here to
823 enable and use it. If you say Y here even though your machine doesn't
824 have a local APIC, then the kernel will still run with no slowdown at
825 all. The local APIC supports CPU-generated self-interrupts (timer,
826 performance counters), and the NMI watchdog which detects hard
830 bool "IO-APIC support on uniprocessors"
831 depends on X86_UP_APIC
833 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
834 SMP-capable replacement for PC-style interrupt controllers. Most
835 SMP systems and many recent uniprocessor systems have one.
837 If you have a single-CPU system with an IO-APIC, you can say Y here
838 to use it. If you say Y here even though your machine doesn't have
839 an IO-APIC, then the kernel will still run with no slowdown at all.
841 config X86_LOCAL_APIC
843 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
847 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
849 config X86_VISWS_APIC
851 depends on X86_32 && X86_VISWS
853 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
854 bool "Reroute for broken boot IRQs"
855 depends on X86_IO_APIC
857 This option enables a workaround that fixes a source of
858 spurious interrupts. This is recommended when threaded
859 interrupt handling is used on systems where the generation of
860 superfluous "boot interrupts" cannot be disabled.
862 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
863 entry in the chipset's IO-APIC is masked (as, e.g. the RT
864 kernel does during interrupt handling). On chipsets where this
865 boot IRQ generation cannot be disabled, this workaround keeps
866 the original IRQ line masked so that only the equivalent "boot
867 IRQ" is delivered to the CPUs. The workaround also tells the
868 kernel to set up the IRQ handler on the boot IRQ line. In this
869 way only one interrupt is delivered to the kernel. Otherwise
870 the spurious second interrupt may cause the kernel to bring
871 down (vital) interrupt lines.
873 Only affects "broken" chipsets. Interrupt sharing may be
874 increased on these systems.
877 bool "Machine Check / overheating reporting"
880 Machine Check support allows the processor to notify the
881 kernel if it detects a problem (e.g. overheating, data corruption).
882 The action the kernel takes depends on the severity of the problem,
883 ranging from warning messages to halting the machine.
887 prompt "Intel MCE features"
888 depends on X86_MCE && X86_LOCAL_APIC
890 Additional support for intel specific MCE features such as
895 prompt "AMD MCE features"
896 depends on X86_MCE && X86_LOCAL_APIC
898 Additional support for AMD specific MCE features such as
899 the DRAM Error Threshold.
901 config X86_ANCIENT_MCE
902 bool "Support for old Pentium 5 / WinChip machine checks"
903 depends on X86_32 && X86_MCE
905 Include support for machine check handling on old Pentium 5 or WinChip
906 systems. These typically need to be enabled explicitely on the command
909 config X86_MCE_THRESHOLD
910 depends on X86_MCE_AMD || X86_MCE_INTEL
913 config X86_MCE_INJECT
915 tristate "Machine check injector support"
917 Provide support for injecting machine checks for testing purposes.
918 If you don't know what a machine check is and you don't do kernel
919 QA it is safe to say n.
921 config X86_THERMAL_VECTOR
923 depends on X86_MCE_INTEL
926 bool "Enable VM86 support" if EXPERT
930 This option is required by programs like DOSEMU to run 16-bit legacy
931 code on X86 processors. It also may be needed by software like
932 XFree86 to initialize some video cards via BIOS. Disabling this
933 option saves about 6k.
936 tristate "Toshiba Laptop support"
939 This adds a driver to safely access the System Management Mode of
940 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
941 not work on models with a Phoenix BIOS. The System Management Mode
942 is used to set the BIOS and power saving options on Toshiba portables.
944 For information on utilities to make use of this driver see the
945 Toshiba Linux utilities web site at:
946 <http://www.buzzard.org.uk/toshiba/>.
948 Say Y if you intend to run this kernel on a Toshiba portable.
952 tristate "Dell laptop support"
955 This adds a driver to safely access the System Management Mode
956 of the CPU on the Dell Inspiron 8000. The System Management Mode
957 is used to read cpu temperature and cooling fan status and to
958 control the fans on the I8K portables.
960 This driver has been tested only on the Inspiron 8000 but it may
961 also work with other Dell laptops. You can force loading on other
962 models by passing the parameter `force=1' to the module. Use at
965 For information on utilities to make use of this driver see the
966 I8K Linux utilities web site at:
967 <http://people.debian.org/~dz/i8k/>
969 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
972 config X86_REBOOTFIXUPS
973 bool "Enable X86 board specific fixups for reboot"
976 This enables chipset and/or board specific fixups to be done
977 in order to get reboot to work correctly. This is only needed on
978 some combinations of hardware and BIOS. The symptom, for which
979 this config is intended, is when reboot ends with a stalled/hung
982 Currently, the only fixup is for the Geode machines using
983 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
985 Say Y if you want to enable the fixup. Currently, it's safe to
986 enable this option even if you don't need it.
990 tristate "CPU microcode loading support"
994 If you say Y here, you will be able to update the microcode on
995 certain Intel and AMD processors. The Intel support is for the
996 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
997 Xeon etc. The AMD support is for families 0x10 and later. You will
998 obviously need the actual microcode binary data itself which is not
999 shipped with the Linux kernel.
1001 This option selects the general module only, you need to select
1002 at least one vendor specific module as well.
1004 To compile this driver as a module, choose M here: the module
1005 will be called microcode.
1007 config MICROCODE_INTEL
1008 bool "Intel microcode loading support"
1009 depends on MICROCODE
1013 This options enables microcode patch loading support for Intel
1016 For latest news and information on obtaining all the required
1017 Intel ingredients for this driver, check:
1018 <http://www.urbanmyth.org/microcode/>.
1020 config MICROCODE_AMD
1021 bool "AMD microcode loading support"
1022 depends on MICROCODE
1025 If you select this option, microcode patch loading support for AMD
1026 processors will be enabled.
1028 config MICROCODE_OLD_INTERFACE
1030 depends on MICROCODE
1033 tristate "/dev/cpu/*/msr - Model-specific register support"
1035 This device gives privileged processes access to the x86
1036 Model-Specific Registers (MSRs). It is a character device with
1037 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1038 MSR accesses are directed to a specific CPU on multi-processor
1042 tristate "/dev/cpu/*/cpuid - CPU information support"
1044 This device gives processes access to the x86 CPUID instruction to
1045 be executed on a specific processor. It is a character device
1046 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1050 prompt "High Memory Support"
1051 default HIGHMEM64G if X86_NUMAQ
1057 depends on !X86_NUMAQ
1059 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1060 However, the address space of 32-bit x86 processors is only 4
1061 Gigabytes large. That means that, if you have a large amount of
1062 physical memory, not all of it can be "permanently mapped" by the
1063 kernel. The physical memory that's not permanently mapped is called
1066 If you are compiling a kernel which will never run on a machine with
1067 more than 1 Gigabyte total physical RAM, answer "off" here (default
1068 choice and suitable for most users). This will result in a "3GB/1GB"
1069 split: 3GB are mapped so that each process sees a 3GB virtual memory
1070 space and the remaining part of the 4GB virtual memory space is used
1071 by the kernel to permanently map as much physical memory as
1074 If the machine has between 1 and 4 Gigabytes physical RAM, then
1077 If more than 4 Gigabytes is used then answer "64GB" here. This
1078 selection turns Intel PAE (Physical Address Extension) mode on.
1079 PAE implements 3-level paging on IA32 processors. PAE is fully
1080 supported by Linux, PAE mode is implemented on all recent Intel
1081 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1082 then the kernel will not boot on CPUs that don't support PAE!
1084 The actual amount of total physical memory will either be
1085 auto detected or can be forced by using a kernel command line option
1086 such as "mem=256M". (Try "man bootparam" or see the documentation of
1087 your boot loader (lilo or loadlin) about how to pass options to the
1088 kernel at boot time.)
1090 If unsure, say "off".
1094 depends on !X86_NUMAQ
1096 Select this if you have a 32-bit processor and between 1 and 4
1097 gigabytes of physical RAM.
1104 Select this if you have a 32-bit processor and more than 4
1105 gigabytes of physical RAM.
1110 depends on EXPERIMENTAL
1111 prompt "Memory split" if EXPERT
1115 Select the desired split between kernel and user memory.
1117 If the address range available to the kernel is less than the
1118 physical memory installed, the remaining memory will be available
1119 as "high memory". Accessing high memory is a little more costly
1120 than low memory, as it needs to be mapped into the kernel first.
1121 Note that increasing the kernel address space limits the range
1122 available to user programs, making the address space there
1123 tighter. Selecting anything other than the default 3G/1G split
1124 will also likely make your kernel incompatible with binary-only
1127 If you are not absolutely sure what you are doing, leave this
1131 bool "3G/1G user/kernel split"
1132 config VMSPLIT_3G_OPT
1134 bool "3G/1G user/kernel split (for full 1G low memory)"
1136 bool "2G/2G user/kernel split"
1137 config VMSPLIT_2G_OPT
1139 bool "2G/2G user/kernel split (for full 2G low memory)"
1141 bool "1G/3G user/kernel split"
1146 default 0xB0000000 if VMSPLIT_3G_OPT
1147 default 0x80000000 if VMSPLIT_2G
1148 default 0x78000000 if VMSPLIT_2G_OPT
1149 default 0x40000000 if VMSPLIT_1G
1155 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1158 bool "PAE (Physical Address Extension) Support"
1159 depends on X86_32 && !HIGHMEM4G
1161 PAE is required for NX support, and furthermore enables
1162 larger swapspace support for non-overcommit purposes. It
1163 has the cost of more pagetable lookup overhead, and also
1164 consumes more pagetable space per process.
1166 config ARCH_PHYS_ADDR_T_64BIT
1168 depends on X86_64 || X86_PAE
1170 config ARCH_DMA_ADDR_T_64BIT
1172 depends on X86_64 || HIGHMEM64G
1174 config DIRECT_GBPAGES
1175 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1179 Allow the kernel linear mapping to use 1GB pages on CPUs that
1180 support it. This can improve the kernel's performance a tiny bit by
1181 reducing TLB pressure. If in doubt, say "Y".
1183 # Common NUMA Features
1185 bool "Numa Memory Allocation and Scheduler Support"
1187 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1188 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1190 Enable NUMA (Non Uniform Memory Access) support.
1192 The kernel will try to allocate memory used by a CPU on the
1193 local memory controller of the CPU and add some more
1194 NUMA awareness to the kernel.
1196 For 64-bit this is recommended if the system is Intel Core i7
1197 (or later), AMD Opteron, or EM64T NUMA.
1199 For 32-bit this is only needed on (rare) 32-bit-only platforms
1200 that support NUMA topologies, such as NUMAQ / Summit, or if you
1201 boot a 32-bit kernel on a 64-bit NUMA platform.
1203 Otherwise, you should say N.
1205 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1206 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1210 prompt "Old style AMD Opteron NUMA detection"
1211 depends on X86_64 && NUMA && PCI
1213 Enable AMD NUMA node topology detection. You should say Y here if
1214 you have a multi processor AMD system. This uses an old method to
1215 read the NUMA configuration directly from the builtin Northbridge
1216 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1217 which also takes priority if both are compiled in.
1219 config X86_64_ACPI_NUMA
1221 prompt "ACPI NUMA detection"
1222 depends on X86_64 && NUMA && ACPI && PCI
1225 Enable ACPI SRAT based node topology detection.
1227 # Some NUMA nodes have memory ranges that span
1228 # other nodes. Even though a pfn is valid and
1229 # between a node's start and end pfns, it may not
1230 # reside on that node. See memmap_init_zone()
1232 config NODES_SPAN_OTHER_NODES
1234 depends on X86_64_ACPI_NUMA
1237 bool "NUMA emulation"
1240 Enable NUMA emulation. A flat machine will be split
1241 into virtual nodes when booted with "numa=fake=N", where N is the
1242 number of nodes. This is only useful for debugging.
1245 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1247 default "10" if MAXSMP
1248 default "6" if X86_64
1249 default "4" if X86_NUMAQ
1251 depends on NEED_MULTIPLE_NODES
1253 Specify the maximum number of NUMA Nodes available on the target
1254 system. Increases memory reserved to accommodate various tables.
1256 config HAVE_ARCH_ALLOC_REMAP
1258 depends on X86_32 && NUMA
1260 config ARCH_HAVE_MEMORY_PRESENT
1262 depends on X86_32 && DISCONTIGMEM
1264 config NEED_NODE_MEMMAP_SIZE
1266 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1268 config ARCH_FLATMEM_ENABLE
1270 depends on X86_32 && !NUMA
1272 config ARCH_DISCONTIGMEM_ENABLE
1274 depends on NUMA && X86_32
1276 config ARCH_DISCONTIGMEM_DEFAULT
1278 depends on NUMA && X86_32
1280 config ARCH_SPARSEMEM_ENABLE
1282 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1283 select SPARSEMEM_STATIC if X86_32
1284 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1286 config ARCH_SPARSEMEM_DEFAULT
1290 config ARCH_SELECT_MEMORY_MODEL
1292 depends on ARCH_SPARSEMEM_ENABLE
1294 config ARCH_MEMORY_PROBE
1296 depends on X86_64 && MEMORY_HOTPLUG
1298 config ARCH_PROC_KCORE_TEXT
1300 depends on X86_64 && PROC_KCORE
1302 config ILLEGAL_POINTER_VALUE
1305 default 0xdead000000000000 if X86_64
1310 bool "Allocate 3rd-level pagetables from highmem"
1313 The VM uses one page table entry for each page of physical memory.
1314 For systems with a lot of RAM, this can be wasteful of precious
1315 low memory. Setting this option will put user-space page table
1316 entries in high memory.
1318 config X86_CHECK_BIOS_CORRUPTION
1319 bool "Check for low memory corruption"
1321 Periodically check for memory corruption in low memory, which
1322 is suspected to be caused by BIOS. Even when enabled in the
1323 configuration, it is disabled at runtime. Enable it by
1324 setting "memory_corruption_check=1" on the kernel command
1325 line. By default it scans the low 64k of memory every 60
1326 seconds; see the memory_corruption_check_size and
1327 memory_corruption_check_period parameters in
1328 Documentation/kernel-parameters.txt to adjust this.
1330 When enabled with the default parameters, this option has
1331 almost no overhead, as it reserves a relatively small amount
1332 of memory and scans it infrequently. It both detects corruption
1333 and prevents it from affecting the running system.
1335 It is, however, intended as a diagnostic tool; if repeatable
1336 BIOS-originated corruption always affects the same memory,
1337 you can use memmap= to prevent the kernel from using that
1340 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1341 bool "Set the default setting of memory_corruption_check"
1342 depends on X86_CHECK_BIOS_CORRUPTION
1345 Set whether the default state of memory_corruption_check is
1348 config X86_RESERVE_LOW
1349 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1353 Specify the amount of low memory to reserve for the BIOS.
1355 The first page contains BIOS data structures that the kernel
1356 must not use, so that page must always be reserved.
1358 By default we reserve the first 64K of physical RAM, as a
1359 number of BIOSes are known to corrupt that memory range
1360 during events such as suspend/resume or monitor cable
1361 insertion, so it must not be used by the kernel.
1363 You can set this to 4 if you are absolutely sure that you
1364 trust the BIOS to get all its memory reservations and usages
1365 right. If you know your BIOS have problems beyond the
1366 default 64K area, you can set this to 640 to avoid using the
1367 entire low memory range.
1369 If you have doubts about the BIOS (e.g. suspend/resume does
1370 not work or there's kernel crashes after certain hardware
1371 hotplug events) then you might want to enable
1372 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1373 typical corruption patterns.
1375 Leave this to the default value of 64 if you are unsure.
1377 config MATH_EMULATION
1379 prompt "Math emulation" if X86_32
1381 Linux can emulate a math coprocessor (used for floating point
1382 operations) if you don't have one. 486DX and Pentium processors have
1383 a math coprocessor built in, 486SX and 386 do not, unless you added
1384 a 487DX or 387, respectively. (The messages during boot time can
1385 give you some hints here ["man dmesg"].) Everyone needs either a
1386 coprocessor or this emulation.
1388 If you don't have a math coprocessor, you need to say Y here; if you
1389 say Y here even though you have a coprocessor, the coprocessor will
1390 be used nevertheless. (This behavior can be changed with the kernel
1391 command line option "no387", which comes handy if your coprocessor
1392 is broken. Try "man bootparam" or see the documentation of your boot
1393 loader (lilo or loadlin) about how to pass options to the kernel at
1394 boot time.) This means that it is a good idea to say Y here if you
1395 intend to use this kernel on different machines.
1397 More information about the internals of the Linux math coprocessor
1398 emulation can be found in <file:arch/x86/math-emu/README>.
1400 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1401 kernel, it won't hurt.
1405 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1407 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1408 the Memory Type Range Registers (MTRRs) may be used to control
1409 processor access to memory ranges. This is most useful if you have
1410 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1411 allows bus write transfers to be combined into a larger transfer
1412 before bursting over the PCI/AGP bus. This can increase performance
1413 of image write operations 2.5 times or more. Saying Y here creates a
1414 /proc/mtrr file which may be used to manipulate your processor's
1415 MTRRs. Typically the X server should use this.
1417 This code has a reasonably generic interface so that similar
1418 control registers on other processors can be easily supported
1421 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1422 Registers (ARRs) which provide a similar functionality to MTRRs. For
1423 these, the ARRs are used to emulate the MTRRs.
1424 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1425 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1426 write-combining. All of these processors are supported by this code
1427 and it makes sense to say Y here if you have one of them.
1429 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1430 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1431 can lead to all sorts of problems, so it's good to say Y here.
1433 You can safely say Y even if your machine doesn't have MTRRs, you'll
1434 just add about 9 KB to your kernel.
1436 See <file:Documentation/x86/mtrr.txt> for more information.
1438 config MTRR_SANITIZER
1440 prompt "MTRR cleanup support"
1443 Convert MTRR layout from continuous to discrete, so X drivers can
1444 add writeback entries.
1446 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1447 The largest mtrr entry size for a continuous block can be set with
1452 config MTRR_SANITIZER_ENABLE_DEFAULT
1453 int "MTRR cleanup enable value (0-1)"
1456 depends on MTRR_SANITIZER
1458 Enable mtrr cleanup default value
1460 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1461 int "MTRR cleanup spare reg num (0-7)"
1464 depends on MTRR_SANITIZER
1466 mtrr cleanup spare entries default, it can be changed via
1467 mtrr_spare_reg_nr=N on the kernel command line.
1471 prompt "x86 PAT support" if EXPERT
1474 Use PAT attributes to setup page level cache control.
1476 PATs are the modern equivalents of MTRRs and are much more
1477 flexible than MTRRs.
1479 Say N here if you see bootup problems (boot crash, boot hang,
1480 spontaneous reboots) or a non-working video driver.
1484 config ARCH_USES_PG_UNCACHED
1490 prompt "x86 architectural random number generator" if EXPERT
1492 Enable the x86 architectural RDRAND instruction
1493 (Intel Bull Mountain technology) to generate random numbers.
1494 If supported, this is a high bandwidth, cryptographically
1495 secure hardware random number generator.
1499 prompt "Supervisor Mode Access Prevention" if EXPERT
1501 Supervisor Mode Access Prevention (SMAP) is a security
1502 feature in newer Intel processors. There is a small
1503 performance cost if this enabled and turned on; there is
1504 also a small increase in the kernel size if this is enabled.
1509 bool "EFI runtime service support"
1512 This enables the kernel to use EFI runtime services that are
1513 available (such as the EFI variable services).
1515 This option is only useful on systems that have EFI firmware.
1516 In addition, you should use the latest ELILO loader available
1517 at <http://elilo.sourceforge.net> in order to take advantage
1518 of EFI runtime services. However, even with this option, the
1519 resultant kernel should continue to boot on existing non-EFI
1523 bool "EFI stub support"
1526 This kernel feature allows a bzImage to be loaded directly
1527 by EFI firmware without the use of a bootloader.
1529 See Documentation/x86/efi-stub.txt for more information.
1533 prompt "Enable seccomp to safely compute untrusted bytecode"
1535 This kernel feature is useful for number crunching applications
1536 that may need to compute untrusted bytecode during their
1537 execution. By using pipes or other transports made available to
1538 the process as file descriptors supporting the read/write
1539 syscalls, it's possible to isolate those applications in
1540 their own address space using seccomp. Once seccomp is
1541 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1542 and the task is only allowed to execute a few safe syscalls
1543 defined by each seccomp mode.
1545 If unsure, say Y. Only embedded should say N here.
1547 config CC_STACKPROTECTOR
1548 bool "Enable -fstack-protector buffer overflow detection"
1550 This option turns on the -fstack-protector GCC feature. This
1551 feature puts, at the beginning of functions, a canary value on
1552 the stack just before the return address, and validates
1553 the value just before actually returning. Stack based buffer
1554 overflows (that need to overwrite this return address) now also
1555 overwrite the canary, which gets detected and the attack is then
1556 neutralized via a kernel panic.
1558 This feature requires gcc version 4.2 or above, or a distribution
1559 gcc with the feature backported. Older versions are automatically
1560 detected and for those versions, this configuration option is
1561 ignored. (and a warning is printed during bootup)
1563 source kernel/Kconfig.hz
1566 bool "kexec system call"
1568 kexec is a system call that implements the ability to shutdown your
1569 current kernel, and to start another kernel. It is like a reboot
1570 but it is independent of the system firmware. And like a reboot
1571 you can start any kernel with it, not just Linux.
1573 The name comes from the similarity to the exec system call.
1575 It is an ongoing process to be certain the hardware in a machine
1576 is properly shutdown, so do not be surprised if this code does not
1577 initially work for you. It may help to enable device hotplugging
1578 support. As of this writing the exact hardware interface is
1579 strongly in flux, so no good recommendation can be made.
1582 bool "kernel crash dumps"
1583 depends on X86_64 || (X86_32 && HIGHMEM)
1585 Generate crash dump after being started by kexec.
1586 This should be normally only set in special crash dump kernels
1587 which are loaded in the main kernel with kexec-tools into
1588 a specially reserved region and then later executed after
1589 a crash by kdump/kexec. The crash dump kernel must be compiled
1590 to a memory address not used by the main kernel or BIOS using
1591 PHYSICAL_START, or it must be built as a relocatable image
1592 (CONFIG_RELOCATABLE=y).
1593 For more details see Documentation/kdump/kdump.txt
1596 bool "kexec jump (EXPERIMENTAL)"
1597 depends on EXPERIMENTAL
1598 depends on KEXEC && HIBERNATION
1600 Jump between original kernel and kexeced kernel and invoke
1601 code in physical address mode via KEXEC
1603 config PHYSICAL_START
1604 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1607 This gives the physical address where the kernel is loaded.
1609 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1610 bzImage will decompress itself to above physical address and
1611 run from there. Otherwise, bzImage will run from the address where
1612 it has been loaded by the boot loader and will ignore above physical
1615 In normal kdump cases one does not have to set/change this option
1616 as now bzImage can be compiled as a completely relocatable image
1617 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1618 address. This option is mainly useful for the folks who don't want
1619 to use a bzImage for capturing the crash dump and want to use a
1620 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1621 to be specifically compiled to run from a specific memory area
1622 (normally a reserved region) and this option comes handy.
1624 So if you are using bzImage for capturing the crash dump,
1625 leave the value here unchanged to 0x1000000 and set
1626 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1627 for capturing the crash dump change this value to start of
1628 the reserved region. In other words, it can be set based on
1629 the "X" value as specified in the "crashkernel=YM@XM"
1630 command line boot parameter passed to the panic-ed
1631 kernel. Please take a look at Documentation/kdump/kdump.txt
1632 for more details about crash dumps.
1634 Usage of bzImage for capturing the crash dump is recommended as
1635 one does not have to build two kernels. Same kernel can be used
1636 as production kernel and capture kernel. Above option should have
1637 gone away after relocatable bzImage support is introduced. But it
1638 is present because there are users out there who continue to use
1639 vmlinux for dump capture. This option should go away down the
1642 Don't change this unless you know what you are doing.
1645 bool "Build a relocatable kernel"
1648 This builds a kernel image that retains relocation information
1649 so it can be loaded someplace besides the default 1MB.
1650 The relocations tend to make the kernel binary about 10% larger,
1651 but are discarded at runtime.
1653 One use is for the kexec on panic case where the recovery kernel
1654 must live at a different physical address than the primary
1657 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1658 it has been loaded at and the compile time physical address
1659 (CONFIG_PHYSICAL_START) is ignored.
1661 # Relocation on x86-32 needs some additional build support
1662 config X86_NEED_RELOCS
1664 depends on X86_32 && RELOCATABLE
1666 config PHYSICAL_ALIGN
1667 hex "Alignment value to which kernel should be aligned" if X86_32
1669 range 0x2000 0x1000000
1671 This value puts the alignment restrictions on physical address
1672 where kernel is loaded and run from. Kernel is compiled for an
1673 address which meets above alignment restriction.
1675 If bootloader loads the kernel at a non-aligned address and
1676 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1677 address aligned to above value and run from there.
1679 If bootloader loads the kernel at a non-aligned address and
1680 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1681 load address and decompress itself to the address it has been
1682 compiled for and run from there. The address for which kernel is
1683 compiled already meets above alignment restrictions. Hence the
1684 end result is that kernel runs from a physical address meeting
1685 above alignment restrictions.
1687 Don't change this unless you know what you are doing.
1690 bool "Support for hot-pluggable CPUs"
1691 depends on SMP && HOTPLUG
1693 Say Y here to allow turning CPUs off and on. CPUs can be
1694 controlled through /sys/devices/system/cpu.
1695 ( Note: power management support will enable this option
1696 automatically on SMP systems. )
1697 Say N if you want to disable CPU hotplug.
1699 config BOOTPARAM_HOTPLUG_CPU0
1700 bool "Set default setting of cpu0_hotpluggable"
1702 depends on HOTPLUG_CPU && EXPERIMENTAL
1704 Set whether default state of cpu0_hotpluggable is on or off.
1706 Say Y here to enable CPU0 hotplug by default. If this switch
1707 is turned on, there is no need to give cpu0_hotplug kernel
1708 parameter and the CPU0 hotplug feature is enabled by default.
1710 Please note: there are two known CPU0 dependencies if you want
1711 to enable the CPU0 hotplug feature either by this switch or by
1712 cpu0_hotplug kernel parameter.
1714 First, resume from hibernate or suspend always starts from CPU0.
1715 So hibernate and suspend are prevented if CPU0 is offline.
1717 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1718 offline if any interrupt can not migrate out of CPU0. There may
1719 be other CPU0 dependencies.
1721 Please make sure the dependencies are under your control before
1722 you enable this feature.
1724 Say N if you don't want to enable CPU0 hotplug feature by default.
1725 You still can enable the CPU0 hotplug feature at boot by kernel
1726 parameter cpu0_hotplug.
1728 config DEBUG_HOTPLUG_CPU0
1730 prompt "Debug CPU0 hotplug"
1731 depends on HOTPLUG_CPU && EXPERIMENTAL
1733 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1734 soon as possible and boots up userspace with CPU0 offlined. User
1735 can online CPU0 back after boot time.
1737 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1738 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1739 compilation or giving cpu0_hotplug kernel parameter at boot.
1745 prompt "Compat VDSO support"
1746 depends on X86_32 || IA32_EMULATION
1748 Map the 32-bit VDSO to the predictable old-style address too.
1750 Say N here if you are running a sufficiently recent glibc
1751 version (2.3.3 or later), to remove the high-mapped
1752 VDSO mapping and to exclusively use the randomized VDSO.
1757 bool "Built-in kernel command line"
1759 Allow for specifying boot arguments to the kernel at
1760 build time. On some systems (e.g. embedded ones), it is
1761 necessary or convenient to provide some or all of the
1762 kernel boot arguments with the kernel itself (that is,
1763 to not rely on the boot loader to provide them.)
1765 To compile command line arguments into the kernel,
1766 set this option to 'Y', then fill in the
1767 the boot arguments in CONFIG_CMDLINE.
1769 Systems with fully functional boot loaders (i.e. non-embedded)
1770 should leave this option set to 'N'.
1773 string "Built-in kernel command string"
1774 depends on CMDLINE_BOOL
1777 Enter arguments here that should be compiled into the kernel
1778 image and used at boot time. If the boot loader provides a
1779 command line at boot time, it is appended to this string to
1780 form the full kernel command line, when the system boots.
1782 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1783 change this behavior.
1785 In most cases, the command line (whether built-in or provided
1786 by the boot loader) should specify the device for the root
1789 config CMDLINE_OVERRIDE
1790 bool "Built-in command line overrides boot loader arguments"
1791 depends on CMDLINE_BOOL
1793 Set this option to 'Y' to have the kernel ignore the boot loader
1794 command line, and use ONLY the built-in command line.
1796 This is used to work around broken boot loaders. This should
1797 be set to 'N' under normal conditions.
1801 config ARCH_ENABLE_MEMORY_HOTPLUG
1803 depends on X86_64 || (X86_32 && HIGHMEM)
1805 config ARCH_ENABLE_MEMORY_HOTREMOVE
1807 depends on MEMORY_HOTPLUG
1809 config USE_PERCPU_NUMA_NODE_ID
1813 menu "Power management and ACPI options"
1815 config ARCH_HIBERNATION_HEADER
1817 depends on X86_64 && HIBERNATION
1819 source "kernel/power/Kconfig"
1821 source "drivers/acpi/Kconfig"
1823 source "drivers/sfi/Kconfig"
1830 tristate "APM (Advanced Power Management) BIOS support"
1831 depends on X86_32 && PM_SLEEP
1833 APM is a BIOS specification for saving power using several different
1834 techniques. This is mostly useful for battery powered laptops with
1835 APM compliant BIOSes. If you say Y here, the system time will be
1836 reset after a RESUME operation, the /proc/apm device will provide
1837 battery status information, and user-space programs will receive
1838 notification of APM "events" (e.g. battery status change).
1840 If you select "Y" here, you can disable actual use of the APM
1841 BIOS by passing the "apm=off" option to the kernel at boot time.
1843 Note that the APM support is almost completely disabled for
1844 machines with more than one CPU.
1846 In order to use APM, you will need supporting software. For location
1847 and more information, read <file:Documentation/power/apm-acpi.txt>
1848 and the Battery Powered Linux mini-HOWTO, available from
1849 <http://www.tldp.org/docs.html#howto>.
1851 This driver does not spin down disk drives (see the hdparm(8)
1852 manpage ("man 8 hdparm") for that), and it doesn't turn off
1853 VESA-compliant "green" monitors.
1855 This driver does not support the TI 4000M TravelMate and the ACER
1856 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1857 desktop machines also don't have compliant BIOSes, and this driver
1858 may cause those machines to panic during the boot phase.
1860 Generally, if you don't have a battery in your machine, there isn't
1861 much point in using this driver and you should say N. If you get
1862 random kernel OOPSes or reboots that don't seem to be related to
1863 anything, try disabling/enabling this option (or disabling/enabling
1866 Some other things you should try when experiencing seemingly random,
1869 1) make sure that you have enough swap space and that it is
1871 2) pass the "no-hlt" option to the kernel
1872 3) switch on floating point emulation in the kernel and pass
1873 the "no387" option to the kernel
1874 4) pass the "floppy=nodma" option to the kernel
1875 5) pass the "mem=4M" option to the kernel (thereby disabling
1876 all but the first 4 MB of RAM)
1877 6) make sure that the CPU is not over clocked.
1878 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1879 8) disable the cache from your BIOS settings
1880 9) install a fan for the video card or exchange video RAM
1881 10) install a better fan for the CPU
1882 11) exchange RAM chips
1883 12) exchange the motherboard.
1885 To compile this driver as a module, choose M here: the
1886 module will be called apm.
1890 config APM_IGNORE_USER_SUSPEND
1891 bool "Ignore USER SUSPEND"
1893 This option will ignore USER SUSPEND requests. On machines with a
1894 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1895 series notebooks, it is necessary to say Y because of a BIOS bug.
1897 config APM_DO_ENABLE
1898 bool "Enable PM at boot time"
1900 Enable APM features at boot time. From page 36 of the APM BIOS
1901 specification: "When disabled, the APM BIOS does not automatically
1902 power manage devices, enter the Standby State, enter the Suspend
1903 State, or take power saving steps in response to CPU Idle calls."
1904 This driver will make CPU Idle calls when Linux is idle (unless this
1905 feature is turned off -- see "Do CPU IDLE calls", below). This
1906 should always save battery power, but more complicated APM features
1907 will be dependent on your BIOS implementation. You may need to turn
1908 this option off if your computer hangs at boot time when using APM
1909 support, or if it beeps continuously instead of suspending. Turn
1910 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1911 T400CDT. This is off by default since most machines do fine without
1915 bool "Make CPU Idle calls when idle"
1917 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1918 On some machines, this can activate improved power savings, such as
1919 a slowed CPU clock rate, when the machine is idle. These idle calls
1920 are made after the idle loop has run for some length of time (e.g.,
1921 333 mS). On some machines, this will cause a hang at boot time or
1922 whenever the CPU becomes idle. (On machines with more than one CPU,
1923 this option does nothing.)
1925 config APM_DISPLAY_BLANK
1926 bool "Enable console blanking using APM"
1928 Enable console blanking using the APM. Some laptops can use this to
1929 turn off the LCD backlight when the screen blanker of the Linux
1930 virtual console blanks the screen. Note that this is only used by
1931 the virtual console screen blanker, and won't turn off the backlight
1932 when using the X Window system. This also doesn't have anything to
1933 do with your VESA-compliant power-saving monitor. Further, this
1934 option doesn't work for all laptops -- it might not turn off your
1935 backlight at all, or it might print a lot of errors to the console,
1936 especially if you are using gpm.
1938 config APM_ALLOW_INTS
1939 bool "Allow interrupts during APM BIOS calls"
1941 Normally we disable external interrupts while we are making calls to
1942 the APM BIOS as a measure to lessen the effects of a badly behaving
1943 BIOS implementation. The BIOS should reenable interrupts if it
1944 needs to. Unfortunately, some BIOSes do not -- especially those in
1945 many of the newer IBM Thinkpads. If you experience hangs when you
1946 suspend, try setting this to Y. Otherwise, say N.
1950 source "drivers/cpufreq/Kconfig"
1952 source "drivers/cpuidle/Kconfig"
1954 source "drivers/idle/Kconfig"
1959 menu "Bus options (PCI etc.)"
1964 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1966 Find out whether you have a PCI motherboard. PCI is the name of a
1967 bus system, i.e. the way the CPU talks to the other stuff inside
1968 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1969 VESA. If you have PCI, say Y, otherwise N.
1972 prompt "PCI access mode"
1973 depends on X86_32 && PCI
1976 On PCI systems, the BIOS can be used to detect the PCI devices and
1977 determine their configuration. However, some old PCI motherboards
1978 have BIOS bugs and may crash if this is done. Also, some embedded
1979 PCI-based systems don't have any BIOS at all. Linux can also try to
1980 detect the PCI hardware directly without using the BIOS.
1982 With this option, you can specify how Linux should detect the
1983 PCI devices. If you choose "BIOS", the BIOS will be used,
1984 if you choose "Direct", the BIOS won't be used, and if you
1985 choose "MMConfig", then PCI Express MMCONFIG will be used.
1986 If you choose "Any", the kernel will try MMCONFIG, then the
1987 direct access method and falls back to the BIOS if that doesn't
1988 work. If unsure, go with the default, which is "Any".
1993 config PCI_GOMMCONFIG
2010 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2012 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2015 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2019 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2023 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2027 depends on PCI && XEN
2035 bool "Support mmconfig PCI config space access"
2036 depends on X86_64 && PCI && ACPI
2038 config PCI_CNB20LE_QUIRK
2039 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2040 depends on PCI && EXPERIMENTAL
2042 Read the PCI windows out of the CNB20LE host bridge. This allows
2043 PCI hotplug to work on systems with the CNB20LE chipset which do
2046 There's no public spec for this chipset, and this functionality
2047 is known to be incomplete.
2049 You should say N unless you know you need this.
2051 source "drivers/pci/pcie/Kconfig"
2053 source "drivers/pci/Kconfig"
2055 # x86_64 have no ISA slots, but can have ISA-style DMA.
2057 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2060 Enables ISA-style DMA support for devices requiring such controllers.
2068 Find out whether you have ISA slots on your motherboard. ISA is the
2069 name of a bus system, i.e. the way the CPU talks to the other stuff
2070 inside your box. Other bus systems are PCI, EISA, MicroChannel
2071 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2072 newer boards don't support it. If you have ISA, say Y, otherwise N.
2078 The Extended Industry Standard Architecture (EISA) bus was
2079 developed as an open alternative to the IBM MicroChannel bus.
2081 The EISA bus provided some of the features of the IBM MicroChannel
2082 bus while maintaining backward compatibility with cards made for
2083 the older ISA bus. The EISA bus saw limited use between 1988 and
2084 1995 when it was made obsolete by the PCI bus.
2086 Say Y here if you are building a kernel for an EISA-based machine.
2090 source "drivers/eisa/Kconfig"
2093 tristate "NatSemi SCx200 support"
2095 This provides basic support for National Semiconductor's
2096 (now AMD's) Geode processors. The driver probes for the
2097 PCI-IDs of several on-chip devices, so its a good dependency
2098 for other scx200_* drivers.
2100 If compiled as a module, the driver is named scx200.
2102 config SCx200HR_TIMER
2103 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2107 This driver provides a clocksource built upon the on-chip
2108 27MHz high-resolution timer. Its also a workaround for
2109 NSC Geode SC-1100's buggy TSC, which loses time when the
2110 processor goes idle (as is done by the scheduler). The
2111 other workaround is idle=poll boot option.
2114 bool "One Laptop Per Child support"
2121 Add support for detecting the unique features of the OLPC
2125 bool "OLPC XO-1 Power Management"
2126 depends on OLPC && MFD_CS5535 && PM_SLEEP
2129 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2132 bool "OLPC XO-1 Real Time Clock"
2133 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2135 Add support for the XO-1 real time clock, which can be used as a
2136 programmable wakeup source.
2139 bool "OLPC XO-1 SCI extras"
2140 depends on OLPC && OLPC_XO1_PM
2145 Add support for SCI-based features of the OLPC XO-1 laptop:
2146 - EC-driven system wakeups
2150 - AC adapter status updates
2151 - Battery status updates
2153 config OLPC_XO15_SCI
2154 bool "OLPC XO-1.5 SCI extras"
2155 depends on OLPC && ACPI
2158 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2159 - EC-driven system wakeups
2160 - AC adapter status updates
2161 - Battery status updates
2164 bool "PCEngines ALIX System Support (LED setup)"
2167 This option enables system support for the PCEngines ALIX.
2168 At present this just sets up LEDs for GPIO control on
2169 ALIX2/3/6 boards. However, other system specific setup should
2172 Note: You must still enable the drivers for GPIO and LED support
2173 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2175 Note: You have to set alix.force=1 for boards with Award BIOS.
2178 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2181 This option enables system support for the Soekris Engineering net5501.
2184 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2188 This option enables system support for the Traverse Technologies GEOS.
2194 depends on CPU_SUP_AMD && PCI
2196 source "drivers/pcmcia/Kconfig"
2198 source "drivers/pci/hotplug/Kconfig"
2201 bool "RapidIO support"
2205 If you say Y here, the kernel will include drivers and
2206 infrastructure code to support RapidIO interconnect devices.
2208 source "drivers/rapidio/Kconfig"
2213 menu "Executable file formats / Emulations"
2215 source "fs/Kconfig.binfmt"
2217 config IA32_EMULATION
2218 bool "IA32 Emulation"
2220 select COMPAT_BINFMT_ELF
2223 Include code to run legacy 32-bit programs under a
2224 64-bit kernel. You should likely turn this on, unless you're
2225 100% sure that you don't have any 32-bit programs left.
2228 tristate "IA32 a.out support"
2229 depends on IA32_EMULATION
2231 Support old a.out binaries in the 32bit emulation.
2234 bool "x32 ABI for 64-bit mode (EXPERIMENTAL)"
2235 depends on X86_64 && IA32_EMULATION && EXPERIMENTAL
2237 Include code to run binaries for the x32 native 32-bit ABI
2238 for 64-bit processors. An x32 process gets access to the
2239 full 64-bit register file and wide data path while leaving
2240 pointers at 32 bits for smaller memory footprint.
2242 You will need a recent binutils (2.22 or later) with
2243 elf32_x86_64 support enabled to compile a kernel with this
2248 depends on IA32_EMULATION || X86_X32
2249 select ARCH_WANT_OLD_COMPAT_IPC
2252 config COMPAT_FOR_U64_ALIGNMENT
2255 config SYSVIPC_COMPAT
2267 config HAVE_ATOMIC_IOMAP
2271 config HAVE_TEXT_POKE_SMP
2273 select STOP_MACHINE if SMP
2275 config X86_DEV_DMA_OPS
2277 depends on X86_64 || STA2X11
2279 config X86_DMA_REMAP
2283 source "net/Kconfig"
2285 source "drivers/Kconfig"
2287 source "drivers/firmware/Kconfig"
2291 source "arch/x86/Kconfig.debug"
2293 source "security/Kconfig"
2295 source "crypto/Kconfig"
2297 source "arch/x86/kvm/Kconfig"
2299 source "lib/Kconfig"
projects / platform / adaptation / renesas_rcar / renesas_kernel.git / blob