3 bool "64-bit kernel" if ARCH = "x86"
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
20 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
27 select ARCH_HAS_ELF_RANDOMIZE
28 select ARCH_HAS_FAST_MULTIPLIER
29 select ARCH_HAS_GCOV_PROFILE_ALL
30 select ARCH_HAS_PMEM_API
31 select ARCH_HAS_MMIO_FLUSH
32 select ARCH_HAS_SG_CHAIN
33 select ARCH_HAVE_NMI_SAFE_CMPXCHG
34 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
35 select ARCH_MIGHT_HAVE_PC_PARPORT
36 select ARCH_MIGHT_HAVE_PC_SERIO
37 select ARCH_SUPPORTS_ATOMIC_RMW
38 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
39 select ARCH_SUPPORTS_INT128 if X86_64
40 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
41 select ARCH_USE_BUILTIN_BSWAP
42 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
43 select ARCH_USE_QUEUED_RWLOCKS
44 select ARCH_USE_QUEUED_SPINLOCKS
45 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
46 select ARCH_WANT_FRAME_POINTERS
47 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
48 select ARCH_WANT_OPTIONAL_GPIOLIB
49 select BUILDTIME_EXTABLE_SORT
51 select CLKSRC_I8253 if X86_32
52 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
53 select CLOCKSOURCE_WATCHDOG
54 select CLONE_BACKWARDS if X86_32
55 select COMPAT_OLD_SIGACTION if IA32_EMULATION
56 select DCACHE_WORD_ACCESS
57 select EDAC_ATOMIC_SCRUB
59 select GENERIC_CLOCKEVENTS
60 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
61 select GENERIC_CLOCKEVENTS_MIN_ADJUST
62 select GENERIC_CMOS_UPDATE
63 select GENERIC_CPU_AUTOPROBE
64 select GENERIC_EARLY_IOREMAP
65 select GENERIC_FIND_FIRST_BIT
67 select GENERIC_IRQ_PROBE
68 select GENERIC_IRQ_SHOW
69 select GENERIC_PENDING_IRQ if SMP
70 select GENERIC_SMP_IDLE_THREAD
71 select GENERIC_STRNCPY_FROM_USER
72 select GENERIC_STRNLEN_USER
73 select GENERIC_TIME_VSYSCALL
74 select HAVE_ACPI_APEI if ACPI
75 select HAVE_ACPI_APEI_NMI if ACPI
76 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
77 select HAVE_AOUT if X86_32
78 select HAVE_ARCH_AUDITSYSCALL
79 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
80 select HAVE_ARCH_JUMP_LABEL
81 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
83 select HAVE_ARCH_KMEMCHECK
84 select HAVE_ARCH_SECCOMP_FILTER
85 select HAVE_ARCH_SOFT_DIRTY if X86_64
86 select HAVE_ARCH_TRACEHOOK
87 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
88 select HAVE_BPF_JIT if X86_64
89 select HAVE_CC_STACKPROTECTOR
90 select HAVE_CMPXCHG_DOUBLE
91 select HAVE_CMPXCHG_LOCAL
92 select HAVE_CONTEXT_TRACKING if X86_64
93 select HAVE_COPY_THREAD_TLS
94 select HAVE_C_RECORDMCOUNT
95 select HAVE_DEBUG_KMEMLEAK
96 select HAVE_DEBUG_STACKOVERFLOW
97 select HAVE_DMA_API_DEBUG
99 select HAVE_DMA_CONTIGUOUS
100 select HAVE_DYNAMIC_FTRACE
101 select HAVE_DYNAMIC_FTRACE_WITH_REGS
102 select HAVE_EFFICIENT_UNALIGNED_ACCESS
103 select HAVE_FENTRY if X86_64
104 select HAVE_FTRACE_MCOUNT_RECORD
105 select HAVE_FUNCTION_GRAPH_FP_TEST
106 select HAVE_FUNCTION_GRAPH_TRACER
107 select HAVE_FUNCTION_TRACER
108 select HAVE_GENERIC_DMA_COHERENT if X86_32
109 select HAVE_HW_BREAKPOINT
111 select HAVE_IOREMAP_PROT
112 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
113 select HAVE_IRQ_TIME_ACCOUNTING
114 select HAVE_KERNEL_BZIP2
115 select HAVE_KERNEL_GZIP
116 select HAVE_KERNEL_LZ4
117 select HAVE_KERNEL_LZMA
118 select HAVE_KERNEL_LZO
119 select HAVE_KERNEL_XZ
121 select HAVE_KPROBES_ON_FTRACE
122 select HAVE_KRETPROBES
124 select HAVE_LIVEPATCH if X86_64
126 select HAVE_MEMBLOCK_NODE_MAP
127 select HAVE_MIXED_BREAKPOINTS_REGS
129 select HAVE_OPTPROBES
130 select HAVE_PCSPKR_PLATFORM
131 select HAVE_PERF_EVENTS
132 select HAVE_PERF_EVENTS_NMI
133 select HAVE_PERF_REGS
134 select HAVE_PERF_USER_STACK_DUMP
135 select HAVE_REGS_AND_STACK_ACCESS_API
136 select HAVE_SYSCALL_TRACEPOINTS
137 select HAVE_UID16 if X86_32
138 select HAVE_UNSTABLE_SCHED_CLOCK
139 select HAVE_USER_RETURN_NOTIFIER
140 select IRQ_FORCED_THREADING
141 select MODULES_USE_ELF_RELA if X86_64
142 select MODULES_USE_ELF_REL if X86_32
143 select OLD_SIGACTION if X86_32
144 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
149 select SYSCTL_EXCEPTION_TRACE
150 select USER_STACKTRACE_SUPPORT
152 select X86_DEV_DMA_OPS if X86_64
153 select X86_FEATURE_NAMES if PROC_FS
155 config INSTRUCTION_DECODER
157 depends on KPROBES || PERF_EVENTS || UPROBES
159 config PERF_EVENTS_INTEL_UNCORE
161 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
165 default "elf32-i386" if X86_32
166 default "elf64-x86-64" if X86_64
168 config ARCH_DEFCONFIG
170 default "arch/x86/configs/i386_defconfig" if X86_32
171 default "arch/x86/configs/x86_64_defconfig" if X86_64
173 config LOCKDEP_SUPPORT
176 config STACKTRACE_SUPPORT
179 config HAVE_LATENCYTOP_SUPPORT
188 config NEED_DMA_MAP_STATE
190 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
192 config NEED_SG_DMA_LENGTH
195 config GENERIC_ISA_DMA
197 depends on ISA_DMA_API
202 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
204 config GENERIC_BUG_RELATIVE_POINTERS
207 config GENERIC_HWEIGHT
210 config ARCH_MAY_HAVE_PC_FDC
212 depends on ISA_DMA_API
214 config RWSEM_XCHGADD_ALGORITHM
217 config GENERIC_CALIBRATE_DELAY
220 config ARCH_HAS_CPU_RELAX
223 config ARCH_HAS_CACHE_LINE_SIZE
226 config HAVE_SETUP_PER_CPU_AREA
229 config NEED_PER_CPU_EMBED_FIRST_CHUNK
232 config NEED_PER_CPU_PAGE_FIRST_CHUNK
235 config ARCH_HIBERNATION_POSSIBLE
238 config ARCH_SUSPEND_POSSIBLE
241 config ARCH_WANT_HUGE_PMD_SHARE
244 config ARCH_WANT_GENERAL_HUGETLB
253 config ARCH_SUPPORTS_OPTIMIZED_INLINING
256 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
259 config KASAN_SHADOW_OFFSET
262 default 0xdffffc0000000000
264 config HAVE_INTEL_TXT
266 depends on INTEL_IOMMU && ACPI
270 depends on X86_32 && SMP
274 depends on X86_64 && SMP
276 config X86_32_LAZY_GS
278 depends on X86_32 && !CC_STACKPROTECTOR
280 config ARCH_HWEIGHT_CFLAGS
282 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
283 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
285 config ARCH_SUPPORTS_UPROBES
288 config FIX_EARLYCON_MEM
291 config PGTABLE_LEVELS
297 source "init/Kconfig"
298 source "kernel/Kconfig.freezer"
300 menu "Processor type and features"
303 bool "DMA memory allocation support" if EXPERT
306 DMA memory allocation support allows devices with less than 32-bit
307 addressing to allocate within the first 16MB of address space.
308 Disable if no such devices will be used.
313 bool "Symmetric multi-processing support"
315 This enables support for systems with more than one CPU. If you have
316 a system with only one CPU, say N. If you have a system with more
319 If you say N here, the kernel will run on uni- and multiprocessor
320 machines, but will use only one CPU of a multiprocessor machine. If
321 you say Y here, the kernel will run on many, but not all,
322 uniprocessor machines. On a uniprocessor machine, the kernel
323 will run faster if you say N here.
325 Note that if you say Y here and choose architecture "586" or
326 "Pentium" under "Processor family", the kernel will not work on 486
327 architectures. Similarly, multiprocessor kernels for the "PPro"
328 architecture may not work on all Pentium based boards.
330 People using multiprocessor machines who say Y here should also say
331 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
332 Management" code will be disabled if you say Y here.
334 See also <file:Documentation/x86/i386/IO-APIC.txt>,
335 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
336 <http://www.tldp.org/docs.html#howto>.
338 If you don't know what to do here, say N.
340 config X86_FEATURE_NAMES
341 bool "Processor feature human-readable names" if EMBEDDED
344 This option compiles in a table of x86 feature bits and corresponding
345 names. This is required to support /proc/cpuinfo and a few kernel
346 messages. You can disable this to save space, at the expense of
347 making those few kernel messages show numeric feature bits instead.
352 bool "Support x2apic"
353 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
355 This enables x2apic support on CPUs that have this feature.
357 This allows 32-bit apic IDs (so it can support very large systems),
358 and accesses the local apic via MSRs not via mmio.
360 If you don't know what to do here, say N.
363 bool "Enable MPS table" if ACPI || SFI
365 depends on X86_LOCAL_APIC
367 For old smp systems that do not have proper acpi support. Newer systems
368 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
371 bool "Support for big SMP systems with more than 8 CPUs"
372 depends on X86_32 && SMP
374 This option is needed for the systems that have more than 8 CPUs
378 depends on X86_GOLDFISH
381 config X86_EXTENDED_PLATFORM
382 bool "Support for extended (non-PC) x86 platforms"
385 If you disable this option then the kernel will only support
386 standard PC platforms. (which covers the vast majority of
389 If you enable this option then you'll be able to select support
390 for the following (non-PC) 32 bit x86 platforms:
391 Goldfish (Android emulator)
394 SGI 320/540 (Visual Workstation)
395 STA2X11-based (e.g. Northville)
396 Moorestown MID devices
398 If you have one of these systems, or if you want to build a
399 generic distribution kernel, say Y here - otherwise say N.
403 config X86_EXTENDED_PLATFORM
404 bool "Support for extended (non-PC) x86 platforms"
407 If you disable this option then the kernel will only support
408 standard PC platforms. (which covers the vast majority of
411 If you enable this option then you'll be able to select support
412 for the following (non-PC) 64 bit x86 platforms:
417 If you have one of these systems, or if you want to build a
418 generic distribution kernel, say Y here - otherwise say N.
420 # This is an alphabetically sorted list of 64 bit extended platforms
421 # Please maintain the alphabetic order if and when there are additions
423 bool "Numascale NumaChip"
425 depends on X86_EXTENDED_PLATFORM
428 depends on X86_X2APIC
429 depends on PCI_MMCONFIG
431 Adds support for Numascale NumaChip large-SMP systems. Needed to
432 enable more than ~168 cores.
433 If you don't have one of these, you should say N here.
437 select HYPERVISOR_GUEST
439 depends on X86_64 && PCI
440 depends on X86_EXTENDED_PLATFORM
443 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
444 supposed to run on these EM64T-based machines. Only choose this option
445 if you have one of these machines.
448 bool "SGI Ultraviolet"
450 depends on X86_EXTENDED_PLATFORM
452 depends on X86_X2APIC
455 This option is needed in order to support SGI Ultraviolet systems.
456 If you don't have one of these, you should say N here.
458 # Following is an alphabetically sorted list of 32 bit extended platforms
459 # Please maintain the alphabetic order if and when there are additions
462 bool "Goldfish (Virtual Platform)"
463 depends on X86_EXTENDED_PLATFORM
465 Enable support for the Goldfish virtual platform used primarily
466 for Android development. Unless you are building for the Android
467 Goldfish emulator say N here.
470 bool "CE4100 TV platform"
472 depends on PCI_GODIRECT
473 depends on X86_IO_APIC
475 depends on X86_EXTENDED_PLATFORM
476 select X86_REBOOTFIXUPS
478 select OF_EARLY_FLATTREE
480 Select for the Intel CE media processor (CE4100) SOC.
481 This option compiles in support for the CE4100 SOC for settop
482 boxes and media devices.
485 bool "Intel MID platform support"
487 depends on X86_EXTENDED_PLATFORM
488 depends on X86_PLATFORM_DEVICES
491 depends on X86_IO_APIC
497 select MFD_INTEL_MSIC
499 Select to build a kernel capable of supporting Intel MID (Mobile
500 Internet Device) platform systems which do not have the PCI legacy
501 interfaces. If you are building for a PC class system say N here.
503 Intel MID platforms are based on an Intel processor and chipset which
504 consume less power than most of the x86 derivatives.
506 config X86_INTEL_QUARK
507 bool "Intel Quark platform support"
509 depends on X86_EXTENDED_PLATFORM
510 depends on X86_PLATFORM_DEVICES
514 depends on X86_IO_APIC
519 Select to include support for Quark X1000 SoC.
520 Say Y here if you have a Quark based system such as the Arduino
521 compatible Intel Galileo.
523 config X86_INTEL_LPSS
524 bool "Intel Low Power Subsystem Support"
529 Select to build support for Intel Low Power Subsystem such as
530 found on Intel Lynxpoint PCH. Selecting this option enables
531 things like clock tree (common clock framework) and pincontrol
532 which are needed by the LPSS peripheral drivers.
534 config X86_AMD_PLATFORM_DEVICE
535 bool "AMD ACPI2Platform devices support"
540 Select to interpret AMD specific ACPI device to platform device
541 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
542 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
543 implemented under PINCTRL subsystem.
546 tristate "Intel SoC IOSF Sideband support for SoC platforms"
549 This option enables sideband register access support for Intel SoC
550 platforms. On these platforms the IOSF sideband is used in lieu of
551 MSR's for some register accesses, mostly but not limited to thermal
552 and power. Drivers may query the availability of this device to
553 determine if they need the sideband in order to work on these
554 platforms. The sideband is available on the following SoC products.
555 This list is not meant to be exclusive.
560 You should say Y if you are running a kernel on one of these SoC's.
562 config IOSF_MBI_DEBUG
563 bool "Enable IOSF sideband access through debugfs"
564 depends on IOSF_MBI && DEBUG_FS
566 Select this option to expose the IOSF sideband access registers (MCR,
567 MDR, MCRX) through debugfs to write and read register information from
568 different units on the SoC. This is most useful for obtaining device
569 state information for debug and analysis. As this is a general access
570 mechanism, users of this option would have specific knowledge of the
571 device they want to access.
573 If you don't require the option or are in doubt, say N.
576 bool "RDC R-321x SoC"
578 depends on X86_EXTENDED_PLATFORM
580 select X86_REBOOTFIXUPS
582 This option is needed for RDC R-321x system-on-chip, also known
584 If you don't have one of these chips, you should say N here.
586 config X86_32_NON_STANDARD
587 bool "Support non-standard 32-bit SMP architectures"
588 depends on X86_32 && SMP
589 depends on X86_EXTENDED_PLATFORM
591 This option compiles in the bigsmp and STA2X11 default
592 subarchitectures. It is intended for a generic binary
593 kernel. If you select them all, kernel will probe it one by
594 one and will fallback to default.
596 # Alphabetically sorted list of Non standard 32 bit platforms
598 config X86_SUPPORTS_MEMORY_FAILURE
600 # MCE code calls memory_failure():
602 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
603 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
604 depends on X86_64 || !SPARSEMEM
605 select ARCH_SUPPORTS_MEMORY_FAILURE
608 bool "STA2X11 Companion Chip Support"
609 depends on X86_32_NON_STANDARD && PCI
610 select X86_DEV_DMA_OPS
614 select ARCH_REQUIRE_GPIOLIB
617 This adds support for boards based on the STA2X11 IO-Hub,
618 a.k.a. "ConneXt". The chip is used in place of the standard
619 PC chipset, so all "standard" peripherals are missing. If this
620 option is selected the kernel will still be able to boot on
621 standard PC machines.
624 tristate "Eurobraille/Iris poweroff module"
627 The Iris machines from EuroBraille do not have APM or ACPI support
628 to shut themselves down properly. A special I/O sequence is
629 needed to do so, which is what this module does at
632 This is only for Iris machines from EuroBraille.
636 config SCHED_OMIT_FRAME_POINTER
638 prompt "Single-depth WCHAN output"
641 Calculate simpler /proc/<PID>/wchan values. If this option
642 is disabled then wchan values will recurse back to the
643 caller function. This provides more accurate wchan values,
644 at the expense of slightly more scheduling overhead.
646 If in doubt, say "Y".
648 menuconfig HYPERVISOR_GUEST
649 bool "Linux guest support"
651 Say Y here to enable options for running Linux under various hyper-
652 visors. This option enables basic hypervisor detection and platform
655 If you say N, all options in this submenu will be skipped and
656 disabled, and Linux guest support won't be built in.
661 bool "Enable paravirtualization code"
663 This changes the kernel so it can modify itself when it is run
664 under a hypervisor, potentially improving performance significantly
665 over full virtualization. However, when run without a hypervisor
666 the kernel is theoretically slower and slightly larger.
668 config PARAVIRT_DEBUG
669 bool "paravirt-ops debugging"
670 depends on PARAVIRT && DEBUG_KERNEL
672 Enable to debug paravirt_ops internals. Specifically, BUG if
673 a paravirt_op is missing when it is called.
675 config PARAVIRT_SPINLOCKS
676 bool "Paravirtualization layer for spinlocks"
677 depends on PARAVIRT && SMP
678 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
680 Paravirtualized spinlocks allow a pvops backend to replace the
681 spinlock implementation with something virtualization-friendly
682 (for example, block the virtual CPU rather than spinning).
684 It has a minimal impact on native kernels and gives a nice performance
685 benefit on paravirtualized KVM / Xen kernels.
687 If you are unsure how to answer this question, answer Y.
689 source "arch/x86/xen/Kconfig"
692 bool "KVM Guest support (including kvmclock)"
694 select PARAVIRT_CLOCK
697 This option enables various optimizations for running under the KVM
698 hypervisor. It includes a paravirtualized clock, so that instead
699 of relying on a PIT (or probably other) emulation by the
700 underlying device model, the host provides the guest with
701 timing infrastructure such as time of day, and system time
704 bool "Enable debug information for KVM Guests in debugfs"
705 depends on KVM_GUEST && DEBUG_FS
708 This option enables collection of various statistics for KVM guest.
709 Statistics are displayed in debugfs filesystem. Enabling this option
710 may incur significant overhead.
712 source "arch/x86/lguest/Kconfig"
714 config PARAVIRT_TIME_ACCOUNTING
715 bool "Paravirtual steal time accounting"
719 Select this option to enable fine granularity task steal time
720 accounting. Time spent executing other tasks in parallel with
721 the current vCPU is discounted from the vCPU power. To account for
722 that, there can be a small performance impact.
724 If in doubt, say N here.
726 config PARAVIRT_CLOCK
729 endif #HYPERVISOR_GUEST
734 source "arch/x86/Kconfig.cpu"
738 prompt "HPET Timer Support" if X86_32
740 Use the IA-PC HPET (High Precision Event Timer) to manage
741 time in preference to the PIT and RTC, if a HPET is
743 HPET is the next generation timer replacing legacy 8254s.
744 The HPET provides a stable time base on SMP
745 systems, unlike the TSC, but it is more expensive to access,
746 as it is off-chip. You can find the HPET spec at
747 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
749 You can safely choose Y here. However, HPET will only be
750 activated if the platform and the BIOS support this feature.
751 Otherwise the 8254 will be used for timing services.
753 Choose N to continue using the legacy 8254 timer.
755 config HPET_EMULATE_RTC
757 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
760 def_bool y if X86_INTEL_MID
761 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
763 depends on X86_INTEL_MID && SFI
765 APB timer is the replacement for 8254, HPET on X86 MID platforms.
766 The APBT provides a stable time base on SMP
767 systems, unlike the TSC, but it is more expensive to access,
768 as it is off-chip. APB timers are always running regardless of CPU
769 C states, they are used as per CPU clockevent device when possible.
771 # Mark as expert because too many people got it wrong.
772 # The code disables itself when not needed.
775 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
776 bool "Enable DMI scanning" if EXPERT
778 Enabled scanning of DMI to identify machine quirks. Say Y
779 here unless you have verified that your setup is not
780 affected by entries in the DMI blacklist. Required by PNP
784 bool "Old AMD GART IOMMU support"
786 depends on X86_64 && PCI && AMD_NB
788 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
789 GART based hardware IOMMUs.
791 The GART supports full DMA access for devices with 32-bit access
792 limitations, on systems with more than 3 GB. This is usually needed
793 for USB, sound, many IDE/SATA chipsets and some other devices.
795 Newer systems typically have a modern AMD IOMMU, supported via
796 the CONFIG_AMD_IOMMU=y config option.
798 In normal configurations this driver is only active when needed:
799 there's more than 3 GB of memory and the system contains a
800 32-bit limited device.
805 bool "IBM Calgary IOMMU support"
807 depends on X86_64 && PCI
809 Support for hardware IOMMUs in IBM's xSeries x366 and x460
810 systems. Needed to run systems with more than 3GB of memory
811 properly with 32-bit PCI devices that do not support DAC
812 (Double Address Cycle). Calgary also supports bus level
813 isolation, where all DMAs pass through the IOMMU. This
814 prevents them from going anywhere except their intended
815 destination. This catches hard-to-find kernel bugs and
816 mis-behaving drivers and devices that do not use the DMA-API
817 properly to set up their DMA buffers. The IOMMU can be
818 turned off at boot time with the iommu=off parameter.
819 Normally the kernel will make the right choice by itself.
822 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
824 prompt "Should Calgary be enabled by default?"
825 depends on CALGARY_IOMMU
827 Should Calgary be enabled by default? if you choose 'y', Calgary
828 will be used (if it exists). If you choose 'n', Calgary will not be
829 used even if it exists. If you choose 'n' and would like to use
830 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
833 # need this always selected by IOMMU for the VIA workaround
837 Support for software bounce buffers used on x86-64 systems
838 which don't have a hardware IOMMU. Using this PCI devices
839 which can only access 32-bits of memory can be used on systems
840 with more than 3 GB of memory.
845 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
848 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
849 depends on X86_64 && SMP && DEBUG_KERNEL
850 select CPUMASK_OFFSTACK
852 Enable maximum number of CPUS and NUMA Nodes for this architecture.
856 int "Maximum number of CPUs" if SMP && !MAXSMP
857 range 2 8 if SMP && X86_32 && !X86_BIGSMP
858 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
859 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
861 default "8192" if MAXSMP
862 default "32" if SMP && X86_BIGSMP
863 default "8" if SMP && X86_32
866 This allows you to specify the maximum number of CPUs which this
867 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
868 supported value is 8192, otherwise the maximum value is 512. The
869 minimum value which makes sense is 2.
871 This is purely to save memory - each supported CPU adds
872 approximately eight kilobytes to the kernel image.
875 bool "SMT (Hyperthreading) scheduler support"
878 SMT scheduler support improves the CPU scheduler's decision making
879 when dealing with Intel Pentium 4 chips with HyperThreading at a
880 cost of slightly increased overhead in some places. If unsure say
885 prompt "Multi-core scheduler support"
888 Multi-core scheduler support improves the CPU scheduler's decision
889 making when dealing with multi-core CPU chips at a cost of slightly
890 increased overhead in some places. If unsure say N here.
892 source "kernel/Kconfig.preempt"
896 depends on !SMP && X86_LOCAL_APIC
899 bool "Local APIC support on uniprocessors" if !PCI_MSI
901 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
903 A local APIC (Advanced Programmable Interrupt Controller) is an
904 integrated interrupt controller in the CPU. If you have a single-CPU
905 system which has a processor with a local APIC, you can say Y here to
906 enable and use it. If you say Y here even though your machine doesn't
907 have a local APIC, then the kernel will still run with no slowdown at
908 all. The local APIC supports CPU-generated self-interrupts (timer,
909 performance counters), and the NMI watchdog which detects hard
913 bool "IO-APIC support on uniprocessors"
914 depends on X86_UP_APIC
916 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
917 SMP-capable replacement for PC-style interrupt controllers. Most
918 SMP systems and many recent uniprocessor systems have one.
920 If you have a single-CPU system with an IO-APIC, you can say Y here
921 to use it. If you say Y here even though your machine doesn't have
922 an IO-APIC, then the kernel will still run with no slowdown at all.
924 config X86_LOCAL_APIC
926 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
927 select IRQ_DOMAIN_HIERARCHY
928 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
932 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
934 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
935 bool "Reroute for broken boot IRQs"
936 depends on X86_IO_APIC
938 This option enables a workaround that fixes a source of
939 spurious interrupts. This is recommended when threaded
940 interrupt handling is used on systems where the generation of
941 superfluous "boot interrupts" cannot be disabled.
943 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
944 entry in the chipset's IO-APIC is masked (as, e.g. the RT
945 kernel does during interrupt handling). On chipsets where this
946 boot IRQ generation cannot be disabled, this workaround keeps
947 the original IRQ line masked so that only the equivalent "boot
948 IRQ" is delivered to the CPUs. The workaround also tells the
949 kernel to set up the IRQ handler on the boot IRQ line. In this
950 way only one interrupt is delivered to the kernel. Otherwise
951 the spurious second interrupt may cause the kernel to bring
952 down (vital) interrupt lines.
954 Only affects "broken" chipsets. Interrupt sharing may be
955 increased on these systems.
958 bool "Machine Check / overheating reporting"
961 Machine Check support allows the processor to notify the
962 kernel if it detects a problem (e.g. overheating, data corruption).
963 The action the kernel takes depends on the severity of the problem,
964 ranging from warning messages to halting the machine.
968 prompt "Intel MCE features"
969 depends on X86_MCE && X86_LOCAL_APIC
971 Additional support for intel specific MCE features such as
976 prompt "AMD MCE features"
977 depends on X86_MCE && X86_LOCAL_APIC
979 Additional support for AMD specific MCE features such as
980 the DRAM Error Threshold.
982 config X86_ANCIENT_MCE
983 bool "Support for old Pentium 5 / WinChip machine checks"
984 depends on X86_32 && X86_MCE
986 Include support for machine check handling on old Pentium 5 or WinChip
987 systems. These typically need to be enabled explicitly on the command
990 config X86_MCE_THRESHOLD
991 depends on X86_MCE_AMD || X86_MCE_INTEL
994 config X86_MCE_INJECT
996 tristate "Machine check injector support"
998 Provide support for injecting machine checks for testing purposes.
999 If you don't know what a machine check is and you don't do kernel
1000 QA it is safe to say n.
1002 config X86_THERMAL_VECTOR
1004 depends on X86_MCE_INTEL
1007 bool "Enable VM86 support" if EXPERT
1011 This option is required by programs like DOSEMU to run
1012 16-bit real mode legacy code on x86 processors. It also may
1013 be needed by software like XFree86 to initialize some video
1014 cards via BIOS. Disabling this option saves about 6K.
1017 bool "Enable support for 16-bit segments" if EXPERT
1020 This option is required by programs like Wine to run 16-bit
1021 protected mode legacy code on x86 processors. Disabling
1022 this option saves about 300 bytes on i386, or around 6K text
1023 plus 16K runtime memory on x86-64,
1027 depends on X86_16BIT && X86_32
1031 depends on X86_16BIT && X86_64
1033 config X86_VSYSCALL_EMULATION
1034 bool "Enable vsyscall emulation" if EXPERT
1038 This enables emulation of the legacy vsyscall page. Disabling
1039 it is roughly equivalent to booting with vsyscall=none, except
1040 that it will also disable the helpful warning if a program
1041 tries to use a vsyscall. With this option set to N, offending
1042 programs will just segfault, citing addresses of the form
1045 This option is required by many programs built before 2013, and
1046 care should be used even with newer programs if set to N.
1048 Disabling this option saves about 7K of kernel size and
1049 possibly 4K of additional runtime pagetable memory.
1052 tristate "Toshiba Laptop support"
1055 This adds a driver to safely access the System Management Mode of
1056 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1057 not work on models with a Phoenix BIOS. The System Management Mode
1058 is used to set the BIOS and power saving options on Toshiba portables.
1060 For information on utilities to make use of this driver see the
1061 Toshiba Linux utilities web site at:
1062 <http://www.buzzard.org.uk/toshiba/>.
1064 Say Y if you intend to run this kernel on a Toshiba portable.
1068 tristate "Dell i8k legacy laptop support"
1070 select SENSORS_DELL_SMM
1072 This option enables legacy /proc/i8k userspace interface in hwmon
1073 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1074 temperature and allows controlling fan speeds of Dell laptops via
1075 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1076 it reports also power and hotkey status. For fan speed control is
1077 needed userspace package i8kutils.
1079 Say Y if you intend to run this kernel on old Dell laptops or want to
1080 use userspace package i8kutils.
1083 config X86_REBOOTFIXUPS
1084 bool "Enable X86 board specific fixups for reboot"
1087 This enables chipset and/or board specific fixups to be done
1088 in order to get reboot to work correctly. This is only needed on
1089 some combinations of hardware and BIOS. The symptom, for which
1090 this config is intended, is when reboot ends with a stalled/hung
1093 Currently, the only fixup is for the Geode machines using
1094 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1096 Say Y if you want to enable the fixup. Currently, it's safe to
1097 enable this option even if you don't need it.
1101 tristate "CPU microcode loading support"
1102 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1106 If you say Y here, you will be able to update the microcode on
1107 certain Intel and AMD processors. The Intel support is for the
1108 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1109 Xeon etc. The AMD support is for families 0x10 and later. You will
1110 obviously need the actual microcode binary data itself which is not
1111 shipped with the Linux kernel.
1113 This option selects the general module only, you need to select
1114 at least one vendor specific module as well.
1116 To compile this driver as a module, choose M here: the module
1117 will be called microcode.
1119 config MICROCODE_INTEL
1120 bool "Intel microcode loading support"
1121 depends on MICROCODE
1125 This options enables microcode patch loading support for Intel
1128 For the current Intel microcode data package go to
1129 <https://downloadcenter.intel.com> and search for
1130 'Linux Processor Microcode Data File'.
1132 config MICROCODE_AMD
1133 bool "AMD microcode loading support"
1134 depends on MICROCODE
1137 If you select this option, microcode patch loading support for AMD
1138 processors will be enabled.
1140 config MICROCODE_OLD_INTERFACE
1142 depends on MICROCODE
1144 config MICROCODE_INTEL_EARLY
1147 config MICROCODE_AMD_EARLY
1150 config MICROCODE_EARLY
1151 bool "Early load microcode"
1152 depends on MICROCODE=y && BLK_DEV_INITRD
1153 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1154 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1157 This option provides functionality to read additional microcode data
1158 at the beginning of initrd image. The data tells kernel to load
1159 microcode to CPU's as early as possible. No functional change if no
1160 microcode data is glued to the initrd, therefore it's safe to say Y.
1163 tristate "/dev/cpu/*/msr - Model-specific register support"
1165 This device gives privileged processes access to the x86
1166 Model-Specific Registers (MSRs). It is a character device with
1167 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1168 MSR accesses are directed to a specific CPU on multi-processor
1172 tristate "/dev/cpu/*/cpuid - CPU information support"
1174 This device gives processes access to the x86 CPUID instruction to
1175 be executed on a specific processor. It is a character device
1176 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1180 prompt "High Memory Support"
1187 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1188 However, the address space of 32-bit x86 processors is only 4
1189 Gigabytes large. That means that, if you have a large amount of
1190 physical memory, not all of it can be "permanently mapped" by the
1191 kernel. The physical memory that's not permanently mapped is called
1194 If you are compiling a kernel which will never run on a machine with
1195 more than 1 Gigabyte total physical RAM, answer "off" here (default
1196 choice and suitable for most users). This will result in a "3GB/1GB"
1197 split: 3GB are mapped so that each process sees a 3GB virtual memory
1198 space and the remaining part of the 4GB virtual memory space is used
1199 by the kernel to permanently map as much physical memory as
1202 If the machine has between 1 and 4 Gigabytes physical RAM, then
1205 If more than 4 Gigabytes is used then answer "64GB" here. This
1206 selection turns Intel PAE (Physical Address Extension) mode on.
1207 PAE implements 3-level paging on IA32 processors. PAE is fully
1208 supported by Linux, PAE mode is implemented on all recent Intel
1209 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1210 then the kernel will not boot on CPUs that don't support PAE!
1212 The actual amount of total physical memory will either be
1213 auto detected or can be forced by using a kernel command line option
1214 such as "mem=256M". (Try "man bootparam" or see the documentation of
1215 your boot loader (lilo or loadlin) about how to pass options to the
1216 kernel at boot time.)
1218 If unsure, say "off".
1223 Select this if you have a 32-bit processor and between 1 and 4
1224 gigabytes of physical RAM.
1231 Select this if you have a 32-bit processor and more than 4
1232 gigabytes of physical RAM.
1237 prompt "Memory split" if EXPERT
1241 Select the desired split between kernel and user memory.
1243 If the address range available to the kernel is less than the
1244 physical memory installed, the remaining memory will be available
1245 as "high memory". Accessing high memory is a little more costly
1246 than low memory, as it needs to be mapped into the kernel first.
1247 Note that increasing the kernel address space limits the range
1248 available to user programs, making the address space there
1249 tighter. Selecting anything other than the default 3G/1G split
1250 will also likely make your kernel incompatible with binary-only
1253 If you are not absolutely sure what you are doing, leave this
1257 bool "3G/1G user/kernel split"
1258 config VMSPLIT_3G_OPT
1260 bool "3G/1G user/kernel split (for full 1G low memory)"
1262 bool "2G/2G user/kernel split"
1263 config VMSPLIT_2G_OPT
1265 bool "2G/2G user/kernel split (for full 2G low memory)"
1267 bool "1G/3G user/kernel split"
1272 default 0xB0000000 if VMSPLIT_3G_OPT
1273 default 0x80000000 if VMSPLIT_2G
1274 default 0x78000000 if VMSPLIT_2G_OPT
1275 default 0x40000000 if VMSPLIT_1G
1281 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1284 bool "PAE (Physical Address Extension) Support"
1285 depends on X86_32 && !HIGHMEM4G
1287 PAE is required for NX support, and furthermore enables
1288 larger swapspace support for non-overcommit purposes. It
1289 has the cost of more pagetable lookup overhead, and also
1290 consumes more pagetable space per process.
1292 config ARCH_PHYS_ADDR_T_64BIT
1294 depends on X86_64 || X86_PAE
1296 config ARCH_DMA_ADDR_T_64BIT
1298 depends on X86_64 || HIGHMEM64G
1300 config X86_DIRECT_GBPAGES
1302 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1304 Certain kernel features effectively disable kernel
1305 linear 1 GB mappings (even if the CPU otherwise
1306 supports them), so don't confuse the user by printing
1307 that we have them enabled.
1309 # Common NUMA Features
1311 bool "Numa Memory Allocation and Scheduler Support"
1313 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1314 default y if X86_BIGSMP
1316 Enable NUMA (Non Uniform Memory Access) support.
1318 The kernel will try to allocate memory used by a CPU on the
1319 local memory controller of the CPU and add some more
1320 NUMA awareness to the kernel.
1322 For 64-bit this is recommended if the system is Intel Core i7
1323 (or later), AMD Opteron, or EM64T NUMA.
1325 For 32-bit this is only needed if you boot a 32-bit
1326 kernel on a 64-bit NUMA platform.
1328 Otherwise, you should say N.
1332 prompt "Old style AMD Opteron NUMA detection"
1333 depends on X86_64 && NUMA && PCI
1335 Enable AMD NUMA node topology detection. You should say Y here if
1336 you have a multi processor AMD system. This uses an old method to
1337 read the NUMA configuration directly from the builtin Northbridge
1338 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1339 which also takes priority if both are compiled in.
1341 config X86_64_ACPI_NUMA
1343 prompt "ACPI NUMA detection"
1344 depends on X86_64 && NUMA && ACPI && PCI
1347 Enable ACPI SRAT based node topology detection.
1349 # Some NUMA nodes have memory ranges that span
1350 # other nodes. Even though a pfn is valid and
1351 # between a node's start and end pfns, it may not
1352 # reside on that node. See memmap_init_zone()
1354 config NODES_SPAN_OTHER_NODES
1356 depends on X86_64_ACPI_NUMA
1359 bool "NUMA emulation"
1362 Enable NUMA emulation. A flat machine will be split
1363 into virtual nodes when booted with "numa=fake=N", where N is the
1364 number of nodes. This is only useful for debugging.
1367 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1369 default "10" if MAXSMP
1370 default "6" if X86_64
1372 depends on NEED_MULTIPLE_NODES
1374 Specify the maximum number of NUMA Nodes available on the target
1375 system. Increases memory reserved to accommodate various tables.
1377 config ARCH_HAVE_MEMORY_PRESENT
1379 depends on X86_32 && DISCONTIGMEM
1381 config NEED_NODE_MEMMAP_SIZE
1383 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1385 config ARCH_FLATMEM_ENABLE
1387 depends on X86_32 && !NUMA
1389 config ARCH_DISCONTIGMEM_ENABLE
1391 depends on NUMA && X86_32
1393 config ARCH_DISCONTIGMEM_DEFAULT
1395 depends on NUMA && X86_32
1397 config ARCH_SPARSEMEM_ENABLE
1399 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1400 select SPARSEMEM_STATIC if X86_32
1401 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1403 config ARCH_SPARSEMEM_DEFAULT
1407 config ARCH_SELECT_MEMORY_MODEL
1409 depends on ARCH_SPARSEMEM_ENABLE
1411 config ARCH_MEMORY_PROBE
1412 bool "Enable sysfs memory/probe interface"
1413 depends on X86_64 && MEMORY_HOTPLUG
1415 This option enables a sysfs memory/probe interface for testing.
1416 See Documentation/memory-hotplug.txt for more information.
1417 If you are unsure how to answer this question, answer N.
1419 config ARCH_PROC_KCORE_TEXT
1421 depends on X86_64 && PROC_KCORE
1423 config ILLEGAL_POINTER_VALUE
1426 default 0xdead000000000000 if X86_64
1430 config X86_PMEM_LEGACY
1431 bool "Support non-standard NVDIMMs and ADR protected memory"
1432 depends on PHYS_ADDR_T_64BIT
1436 Treat memory marked using the non-standard e820 type of 12 as used
1437 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1438 The kernel will offer these regions to the 'pmem' driver so
1439 they can be used for persistent storage.
1444 bool "Allocate 3rd-level pagetables from highmem"
1447 The VM uses one page table entry for each page of physical memory.
1448 For systems with a lot of RAM, this can be wasteful of precious
1449 low memory. Setting this option will put user-space page table
1450 entries in high memory.
1452 config X86_CHECK_BIOS_CORRUPTION
1453 bool "Check for low memory corruption"
1455 Periodically check for memory corruption in low memory, which
1456 is suspected to be caused by BIOS. Even when enabled in the
1457 configuration, it is disabled at runtime. Enable it by
1458 setting "memory_corruption_check=1" on the kernel command
1459 line. By default it scans the low 64k of memory every 60
1460 seconds; see the memory_corruption_check_size and
1461 memory_corruption_check_period parameters in
1462 Documentation/kernel-parameters.txt to adjust this.
1464 When enabled with the default parameters, this option has
1465 almost no overhead, as it reserves a relatively small amount
1466 of memory and scans it infrequently. It both detects corruption
1467 and prevents it from affecting the running system.
1469 It is, however, intended as a diagnostic tool; if repeatable
1470 BIOS-originated corruption always affects the same memory,
1471 you can use memmap= to prevent the kernel from using that
1474 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1475 bool "Set the default setting of memory_corruption_check"
1476 depends on X86_CHECK_BIOS_CORRUPTION
1479 Set whether the default state of memory_corruption_check is
1482 config X86_RESERVE_LOW
1483 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1487 Specify the amount of low memory to reserve for the BIOS.
1489 The first page contains BIOS data structures that the kernel
1490 must not use, so that page must always be reserved.
1492 By default we reserve the first 64K of physical RAM, as a
1493 number of BIOSes are known to corrupt that memory range
1494 during events such as suspend/resume or monitor cable
1495 insertion, so it must not be used by the kernel.
1497 You can set this to 4 if you are absolutely sure that you
1498 trust the BIOS to get all its memory reservations and usages
1499 right. If you know your BIOS have problems beyond the
1500 default 64K area, you can set this to 640 to avoid using the
1501 entire low memory range.
1503 If you have doubts about the BIOS (e.g. suspend/resume does
1504 not work or there's kernel crashes after certain hardware
1505 hotplug events) then you might want to enable
1506 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1507 typical corruption patterns.
1509 Leave this to the default value of 64 if you are unsure.
1511 config MATH_EMULATION
1513 prompt "Math emulation" if X86_32
1515 Linux can emulate a math coprocessor (used for floating point
1516 operations) if you don't have one. 486DX and Pentium processors have
1517 a math coprocessor built in, 486SX and 386 do not, unless you added
1518 a 487DX or 387, respectively. (The messages during boot time can
1519 give you some hints here ["man dmesg"].) Everyone needs either a
1520 coprocessor or this emulation.
1522 If you don't have a math coprocessor, you need to say Y here; if you
1523 say Y here even though you have a coprocessor, the coprocessor will
1524 be used nevertheless. (This behavior can be changed with the kernel
1525 command line option "no387", which comes handy if your coprocessor
1526 is broken. Try "man bootparam" or see the documentation of your boot
1527 loader (lilo or loadlin) about how to pass options to the kernel at
1528 boot time.) This means that it is a good idea to say Y here if you
1529 intend to use this kernel on different machines.
1531 More information about the internals of the Linux math coprocessor
1532 emulation can be found in <file:arch/x86/math-emu/README>.
1534 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1535 kernel, it won't hurt.
1539 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1541 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1542 the Memory Type Range Registers (MTRRs) may be used to control
1543 processor access to memory ranges. This is most useful if you have
1544 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1545 allows bus write transfers to be combined into a larger transfer
1546 before bursting over the PCI/AGP bus. This can increase performance
1547 of image write operations 2.5 times or more. Saying Y here creates a
1548 /proc/mtrr file which may be used to manipulate your processor's
1549 MTRRs. Typically the X server should use this.
1551 This code has a reasonably generic interface so that similar
1552 control registers on other processors can be easily supported
1555 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1556 Registers (ARRs) which provide a similar functionality to MTRRs. For
1557 these, the ARRs are used to emulate the MTRRs.
1558 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1559 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1560 write-combining. All of these processors are supported by this code
1561 and it makes sense to say Y here if you have one of them.
1563 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1564 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1565 can lead to all sorts of problems, so it's good to say Y here.
1567 You can safely say Y even if your machine doesn't have MTRRs, you'll
1568 just add about 9 KB to your kernel.
1570 See <file:Documentation/x86/mtrr.txt> for more information.
1572 config MTRR_SANITIZER
1574 prompt "MTRR cleanup support"
1577 Convert MTRR layout from continuous to discrete, so X drivers can
1578 add writeback entries.
1580 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1581 The largest mtrr entry size for a continuous block can be set with
1586 config MTRR_SANITIZER_ENABLE_DEFAULT
1587 int "MTRR cleanup enable value (0-1)"
1590 depends on MTRR_SANITIZER
1592 Enable mtrr cleanup default value
1594 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1595 int "MTRR cleanup spare reg num (0-7)"
1598 depends on MTRR_SANITIZER
1600 mtrr cleanup spare entries default, it can be changed via
1601 mtrr_spare_reg_nr=N on the kernel command line.
1605 prompt "x86 PAT support" if EXPERT
1608 Use PAT attributes to setup page level cache control.
1610 PATs are the modern equivalents of MTRRs and are much more
1611 flexible than MTRRs.
1613 Say N here if you see bootup problems (boot crash, boot hang,
1614 spontaneous reboots) or a non-working video driver.
1618 config ARCH_USES_PG_UNCACHED
1624 prompt "x86 architectural random number generator" if EXPERT
1626 Enable the x86 architectural RDRAND instruction
1627 (Intel Bull Mountain technology) to generate random numbers.
1628 If supported, this is a high bandwidth, cryptographically
1629 secure hardware random number generator.
1633 prompt "Supervisor Mode Access Prevention" if EXPERT
1635 Supervisor Mode Access Prevention (SMAP) is a security
1636 feature in newer Intel processors. There is a small
1637 performance cost if this enabled and turned on; there is
1638 also a small increase in the kernel size if this is enabled.
1642 config X86_INTEL_MPX
1643 prompt "Intel MPX (Memory Protection Extensions)"
1645 depends on CPU_SUP_INTEL
1647 MPX provides hardware features that can be used in
1648 conjunction with compiler-instrumented code to check
1649 memory references. It is designed to detect buffer
1650 overflow or underflow bugs.
1652 This option enables running applications which are
1653 instrumented or otherwise use MPX. It does not use MPX
1654 itself inside the kernel or to protect the kernel
1655 against bad memory references.
1657 Enabling this option will make the kernel larger:
1658 ~8k of kernel text and 36 bytes of data on a 64-bit
1659 defconfig. It adds a long to the 'mm_struct' which
1660 will increase the kernel memory overhead of each
1661 process and adds some branches to paths used during
1662 exec() and munmap().
1664 For details, see Documentation/x86/intel_mpx.txt
1669 bool "EFI runtime service support"
1672 select EFI_RUNTIME_WRAPPERS
1674 This enables the kernel to use EFI runtime services that are
1675 available (such as the EFI variable services).
1677 This option is only useful on systems that have EFI firmware.
1678 In addition, you should use the latest ELILO loader available
1679 at <http://elilo.sourceforge.net> in order to take advantage
1680 of EFI runtime services. However, even with this option, the
1681 resultant kernel should continue to boot on existing non-EFI
1685 bool "EFI stub support"
1686 depends on EFI && !X86_USE_3DNOW
1689 This kernel feature allows a bzImage to be loaded directly
1690 by EFI firmware without the use of a bootloader.
1692 See Documentation/efi-stub.txt for more information.
1695 bool "EFI mixed-mode support"
1696 depends on EFI_STUB && X86_64
1698 Enabling this feature allows a 64-bit kernel to be booted
1699 on a 32-bit firmware, provided that your CPU supports 64-bit
1702 Note that it is not possible to boot a mixed-mode enabled
1703 kernel via the EFI boot stub - a bootloader that supports
1704 the EFI handover protocol must be used.
1710 prompt "Enable seccomp to safely compute untrusted bytecode"
1712 This kernel feature is useful for number crunching applications
1713 that may need to compute untrusted bytecode during their
1714 execution. By using pipes or other transports made available to
1715 the process as file descriptors supporting the read/write
1716 syscalls, it's possible to isolate those applications in
1717 their own address space using seccomp. Once seccomp is
1718 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1719 and the task is only allowed to execute a few safe syscalls
1720 defined by each seccomp mode.
1722 If unsure, say Y. Only embedded should say N here.
1724 source kernel/Kconfig.hz
1727 bool "kexec system call"
1729 kexec is a system call that implements the ability to shutdown your
1730 current kernel, and to start another kernel. It is like a reboot
1731 but it is independent of the system firmware. And like a reboot
1732 you can start any kernel with it, not just Linux.
1734 The name comes from the similarity to the exec system call.
1736 It is an ongoing process to be certain the hardware in a machine
1737 is properly shutdown, so do not be surprised if this code does not
1738 initially work for you. As of this writing the exact hardware
1739 interface is strongly in flux, so no good recommendation can be
1743 bool "kexec file based system call"
1748 depends on CRYPTO_SHA256=y
1750 This is new version of kexec system call. This system call is
1751 file based and takes file descriptors as system call argument
1752 for kernel and initramfs as opposed to list of segments as
1753 accepted by previous system call.
1755 config KEXEC_VERIFY_SIG
1756 bool "Verify kernel signature during kexec_file_load() syscall"
1757 depends on KEXEC_FILE
1759 This option makes kernel signature verification mandatory for
1760 the kexec_file_load() syscall.
1762 In addition to that option, you need to enable signature
1763 verification for the corresponding kernel image type being
1764 loaded in order for this to work.
1766 config KEXEC_BZIMAGE_VERIFY_SIG
1767 bool "Enable bzImage signature verification support"
1768 depends on KEXEC_VERIFY_SIG
1769 depends on SIGNED_PE_FILE_VERIFICATION
1770 select SYSTEM_TRUSTED_KEYRING
1772 Enable bzImage signature verification support.
1775 bool "kernel crash dumps"
1776 depends on X86_64 || (X86_32 && HIGHMEM)
1778 Generate crash dump after being started by kexec.
1779 This should be normally only set in special crash dump kernels
1780 which are loaded in the main kernel with kexec-tools into
1781 a specially reserved region and then later executed after
1782 a crash by kdump/kexec. The crash dump kernel must be compiled
1783 to a memory address not used by the main kernel or BIOS using
1784 PHYSICAL_START, or it must be built as a relocatable image
1785 (CONFIG_RELOCATABLE=y).
1786 For more details see Documentation/kdump/kdump.txt
1790 depends on KEXEC && HIBERNATION
1792 Jump between original kernel and kexeced kernel and invoke
1793 code in physical address mode via KEXEC
1795 config PHYSICAL_START
1796 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1799 This gives the physical address where the kernel is loaded.
1801 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1802 bzImage will decompress itself to above physical address and
1803 run from there. Otherwise, bzImage will run from the address where
1804 it has been loaded by the boot loader and will ignore above physical
1807 In normal kdump cases one does not have to set/change this option
1808 as now bzImage can be compiled as a completely relocatable image
1809 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1810 address. This option is mainly useful for the folks who don't want
1811 to use a bzImage for capturing the crash dump and want to use a
1812 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1813 to be specifically compiled to run from a specific memory area
1814 (normally a reserved region) and this option comes handy.
1816 So if you are using bzImage for capturing the crash dump,
1817 leave the value here unchanged to 0x1000000 and set
1818 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1819 for capturing the crash dump change this value to start of
1820 the reserved region. In other words, it can be set based on
1821 the "X" value as specified in the "crashkernel=YM@XM"
1822 command line boot parameter passed to the panic-ed
1823 kernel. Please take a look at Documentation/kdump/kdump.txt
1824 for more details about crash dumps.
1826 Usage of bzImage for capturing the crash dump is recommended as
1827 one does not have to build two kernels. Same kernel can be used
1828 as production kernel and capture kernel. Above option should have
1829 gone away after relocatable bzImage support is introduced. But it
1830 is present because there are users out there who continue to use
1831 vmlinux for dump capture. This option should go away down the
1834 Don't change this unless you know what you are doing.
1837 bool "Build a relocatable kernel"
1840 This builds a kernel image that retains relocation information
1841 so it can be loaded someplace besides the default 1MB.
1842 The relocations tend to make the kernel binary about 10% larger,
1843 but are discarded at runtime.
1845 One use is for the kexec on panic case where the recovery kernel
1846 must live at a different physical address than the primary
1849 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1850 it has been loaded at and the compile time physical address
1851 (CONFIG_PHYSICAL_START) is used as the minimum location.
1853 config RANDOMIZE_BASE
1854 bool "Randomize the address of the kernel image"
1855 depends on RELOCATABLE
1858 Randomizes the physical and virtual address at which the
1859 kernel image is decompressed, as a security feature that
1860 deters exploit attempts relying on knowledge of the location
1861 of kernel internals.
1863 Entropy is generated using the RDRAND instruction if it is
1864 supported. If RDTSC is supported, it is used as well. If
1865 neither RDRAND nor RDTSC are supported, then randomness is
1866 read from the i8254 timer.
1868 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1869 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1870 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1871 minimum of 2MiB, only 10 bits of entropy is theoretically
1872 possible. At best, due to page table layouts, 64-bit can use
1873 9 bits of entropy and 32-bit uses 8 bits.
1877 config RANDOMIZE_BASE_MAX_OFFSET
1878 hex "Maximum kASLR offset allowed" if EXPERT
1879 depends on RANDOMIZE_BASE
1880 range 0x0 0x20000000 if X86_32
1881 default "0x20000000" if X86_32
1882 range 0x0 0x40000000 if X86_64
1883 default "0x40000000" if X86_64
1885 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1886 memory is used to determine the maximal offset in bytes that will
1887 be applied to the kernel when kernel Address Space Layout
1888 Randomization (kASLR) is active. This must be a multiple of
1891 On 32-bit this is limited to 512MiB by page table layouts. The
1894 On 64-bit this is limited by how the kernel fixmap page table is
1895 positioned, so this cannot be larger than 1GiB currently. Without
1896 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1897 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1898 modules area will shrink to compensate, up to the current maximum
1899 1GiB to 1GiB split. The default is 1GiB.
1901 If unsure, leave at the default value.
1903 # Relocation on x86 needs some additional build support
1904 config X86_NEED_RELOCS
1906 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1908 config PHYSICAL_ALIGN
1909 hex "Alignment value to which kernel should be aligned"
1911 range 0x2000 0x1000000 if X86_32
1912 range 0x200000 0x1000000 if X86_64
1914 This value puts the alignment restrictions on physical address
1915 where kernel is loaded and run from. Kernel is compiled for an
1916 address which meets above alignment restriction.
1918 If bootloader loads the kernel at a non-aligned address and
1919 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1920 address aligned to above value and run from there.
1922 If bootloader loads the kernel at a non-aligned address and
1923 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1924 load address and decompress itself to the address it has been
1925 compiled for and run from there. The address for which kernel is
1926 compiled already meets above alignment restrictions. Hence the
1927 end result is that kernel runs from a physical address meeting
1928 above alignment restrictions.
1930 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1931 this value must be a multiple of 0x200000.
1933 Don't change this unless you know what you are doing.
1936 bool "Support for hot-pluggable CPUs"
1939 Say Y here to allow turning CPUs off and on. CPUs can be
1940 controlled through /sys/devices/system/cpu.
1941 ( Note: power management support will enable this option
1942 automatically on SMP systems. )
1943 Say N if you want to disable CPU hotplug.
1945 config BOOTPARAM_HOTPLUG_CPU0
1946 bool "Set default setting of cpu0_hotpluggable"
1948 depends on HOTPLUG_CPU
1950 Set whether default state of cpu0_hotpluggable is on or off.
1952 Say Y here to enable CPU0 hotplug by default. If this switch
1953 is turned on, there is no need to give cpu0_hotplug kernel
1954 parameter and the CPU0 hotplug feature is enabled by default.
1956 Please note: there are two known CPU0 dependencies if you want
1957 to enable the CPU0 hotplug feature either by this switch or by
1958 cpu0_hotplug kernel parameter.
1960 First, resume from hibernate or suspend always starts from CPU0.
1961 So hibernate and suspend are prevented if CPU0 is offline.
1963 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1964 offline if any interrupt can not migrate out of CPU0. There may
1965 be other CPU0 dependencies.
1967 Please make sure the dependencies are under your control before
1968 you enable this feature.
1970 Say N if you don't want to enable CPU0 hotplug feature by default.
1971 You still can enable the CPU0 hotplug feature at boot by kernel
1972 parameter cpu0_hotplug.
1974 config DEBUG_HOTPLUG_CPU0
1976 prompt "Debug CPU0 hotplug"
1977 depends on HOTPLUG_CPU
1979 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1980 soon as possible and boots up userspace with CPU0 offlined. User
1981 can online CPU0 back after boot time.
1983 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1984 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1985 compilation or giving cpu0_hotplug kernel parameter at boot.
1991 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1992 depends on X86_32 || IA32_EMULATION
1994 Certain buggy versions of glibc will crash if they are
1995 presented with a 32-bit vDSO that is not mapped at the address
1996 indicated in its segment table.
1998 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1999 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2000 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2001 the only released version with the bug, but OpenSUSE 9
2002 contains a buggy "glibc 2.3.2".
2004 The symptom of the bug is that everything crashes on startup, saying:
2005 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2007 Saying Y here changes the default value of the vdso32 boot
2008 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2009 This works around the glibc bug but hurts performance.
2011 If unsure, say N: if you are compiling your own kernel, you
2012 are unlikely to be using a buggy version of glibc.
2015 bool "Built-in kernel command line"
2017 Allow for specifying boot arguments to the kernel at
2018 build time. On some systems (e.g. embedded ones), it is
2019 necessary or convenient to provide some or all of the
2020 kernel boot arguments with the kernel itself (that is,
2021 to not rely on the boot loader to provide them.)
2023 To compile command line arguments into the kernel,
2024 set this option to 'Y', then fill in the
2025 boot arguments in CONFIG_CMDLINE.
2027 Systems with fully functional boot loaders (i.e. non-embedded)
2028 should leave this option set to 'N'.
2031 string "Built-in kernel command string"
2032 depends on CMDLINE_BOOL
2035 Enter arguments here that should be compiled into the kernel
2036 image and used at boot time. If the boot loader provides a
2037 command line at boot time, it is appended to this string to
2038 form the full kernel command line, when the system boots.
2040 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2041 change this behavior.
2043 In most cases, the command line (whether built-in or provided
2044 by the boot loader) should specify the device for the root
2047 config CMDLINE_OVERRIDE
2048 bool "Built-in command line overrides boot loader arguments"
2049 depends on CMDLINE_BOOL
2051 Set this option to 'Y' to have the kernel ignore the boot loader
2052 command line, and use ONLY the built-in command line.
2054 This is used to work around broken boot loaders. This should
2055 be set to 'N' under normal conditions.
2057 source "kernel/livepatch/Kconfig"
2061 config ARCH_ENABLE_MEMORY_HOTPLUG
2063 depends on X86_64 || (X86_32 && HIGHMEM)
2065 config ARCH_ENABLE_MEMORY_HOTREMOVE
2067 depends on MEMORY_HOTPLUG
2069 config USE_PERCPU_NUMA_NODE_ID
2073 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2075 depends on X86_64 || X86_PAE
2077 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2079 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2081 menu "Power management and ACPI options"
2083 config ARCH_HIBERNATION_HEADER
2085 depends on X86_64 && HIBERNATION
2087 source "kernel/power/Kconfig"
2089 source "drivers/acpi/Kconfig"
2091 source "drivers/sfi/Kconfig"
2098 tristate "APM (Advanced Power Management) BIOS support"
2099 depends on X86_32 && PM_SLEEP
2101 APM is a BIOS specification for saving power using several different
2102 techniques. This is mostly useful for battery powered laptops with
2103 APM compliant BIOSes. If you say Y here, the system time will be
2104 reset after a RESUME operation, the /proc/apm device will provide
2105 battery status information, and user-space programs will receive
2106 notification of APM "events" (e.g. battery status change).
2108 If you select "Y" here, you can disable actual use of the APM
2109 BIOS by passing the "apm=off" option to the kernel at boot time.
2111 Note that the APM support is almost completely disabled for
2112 machines with more than one CPU.
2114 In order to use APM, you will need supporting software. For location
2115 and more information, read <file:Documentation/power/apm-acpi.txt>
2116 and the Battery Powered Linux mini-HOWTO, available from
2117 <http://www.tldp.org/docs.html#howto>.
2119 This driver does not spin down disk drives (see the hdparm(8)
2120 manpage ("man 8 hdparm") for that), and it doesn't turn off
2121 VESA-compliant "green" monitors.
2123 This driver does not support the TI 4000M TravelMate and the ACER
2124 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2125 desktop machines also don't have compliant BIOSes, and this driver
2126 may cause those machines to panic during the boot phase.
2128 Generally, if you don't have a battery in your machine, there isn't
2129 much point in using this driver and you should say N. If you get
2130 random kernel OOPSes or reboots that don't seem to be related to
2131 anything, try disabling/enabling this option (or disabling/enabling
2134 Some other things you should try when experiencing seemingly random,
2137 1) make sure that you have enough swap space and that it is
2139 2) pass the "no-hlt" option to the kernel
2140 3) switch on floating point emulation in the kernel and pass
2141 the "no387" option to the kernel
2142 4) pass the "floppy=nodma" option to the kernel
2143 5) pass the "mem=4M" option to the kernel (thereby disabling
2144 all but the first 4 MB of RAM)
2145 6) make sure that the CPU is not over clocked.
2146 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2147 8) disable the cache from your BIOS settings
2148 9) install a fan for the video card or exchange video RAM
2149 10) install a better fan for the CPU
2150 11) exchange RAM chips
2151 12) exchange the motherboard.
2153 To compile this driver as a module, choose M here: the
2154 module will be called apm.
2158 config APM_IGNORE_USER_SUSPEND
2159 bool "Ignore USER SUSPEND"
2161 This option will ignore USER SUSPEND requests. On machines with a
2162 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2163 series notebooks, it is necessary to say Y because of a BIOS bug.
2165 config APM_DO_ENABLE
2166 bool "Enable PM at boot time"
2168 Enable APM features at boot time. From page 36 of the APM BIOS
2169 specification: "When disabled, the APM BIOS does not automatically
2170 power manage devices, enter the Standby State, enter the Suspend
2171 State, or take power saving steps in response to CPU Idle calls."
2172 This driver will make CPU Idle calls when Linux is idle (unless this
2173 feature is turned off -- see "Do CPU IDLE calls", below). This
2174 should always save battery power, but more complicated APM features
2175 will be dependent on your BIOS implementation. You may need to turn
2176 this option off if your computer hangs at boot time when using APM
2177 support, or if it beeps continuously instead of suspending. Turn
2178 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2179 T400CDT. This is off by default since most machines do fine without
2184 bool "Make CPU Idle calls when idle"
2186 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2187 On some machines, this can activate improved power savings, such as
2188 a slowed CPU clock rate, when the machine is idle. These idle calls
2189 are made after the idle loop has run for some length of time (e.g.,
2190 333 mS). On some machines, this will cause a hang at boot time or
2191 whenever the CPU becomes idle. (On machines with more than one CPU,
2192 this option does nothing.)
2194 config APM_DISPLAY_BLANK
2195 bool "Enable console blanking using APM"
2197 Enable console blanking using the APM. Some laptops can use this to
2198 turn off the LCD backlight when the screen blanker of the Linux
2199 virtual console blanks the screen. Note that this is only used by
2200 the virtual console screen blanker, and won't turn off the backlight
2201 when using the X Window system. This also doesn't have anything to
2202 do with your VESA-compliant power-saving monitor. Further, this
2203 option doesn't work for all laptops -- it might not turn off your
2204 backlight at all, or it might print a lot of errors to the console,
2205 especially if you are using gpm.
2207 config APM_ALLOW_INTS
2208 bool "Allow interrupts during APM BIOS calls"
2210 Normally we disable external interrupts while we are making calls to
2211 the APM BIOS as a measure to lessen the effects of a badly behaving
2212 BIOS implementation. The BIOS should reenable interrupts if it
2213 needs to. Unfortunately, some BIOSes do not -- especially those in
2214 many of the newer IBM Thinkpads. If you experience hangs when you
2215 suspend, try setting this to Y. Otherwise, say N.
2219 source "drivers/cpufreq/Kconfig"
2221 source "drivers/cpuidle/Kconfig"
2223 source "drivers/idle/Kconfig"
2228 menu "Bus options (PCI etc.)"
2234 Find out whether you have a PCI motherboard. PCI is the name of a
2235 bus system, i.e. the way the CPU talks to the other stuff inside
2236 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2237 VESA. If you have PCI, say Y, otherwise N.
2240 prompt "PCI access mode"
2241 depends on X86_32 && PCI
2244 On PCI systems, the BIOS can be used to detect the PCI devices and
2245 determine their configuration. However, some old PCI motherboards
2246 have BIOS bugs and may crash if this is done. Also, some embedded
2247 PCI-based systems don't have any BIOS at all. Linux can also try to
2248 detect the PCI hardware directly without using the BIOS.
2250 With this option, you can specify how Linux should detect the
2251 PCI devices. If you choose "BIOS", the BIOS will be used,
2252 if you choose "Direct", the BIOS won't be used, and if you
2253 choose "MMConfig", then PCI Express MMCONFIG will be used.
2254 If you choose "Any", the kernel will try MMCONFIG, then the
2255 direct access method and falls back to the BIOS if that doesn't
2256 work. If unsure, go with the default, which is "Any".
2261 config PCI_GOMMCONFIG
2278 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2280 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2283 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2287 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2291 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2295 depends on PCI && XEN
2303 bool "Support mmconfig PCI config space access"
2304 depends on X86_64 && PCI && ACPI
2306 config PCI_CNB20LE_QUIRK
2307 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2310 Read the PCI windows out of the CNB20LE host bridge. This allows
2311 PCI hotplug to work on systems with the CNB20LE chipset which do
2314 There's no public spec for this chipset, and this functionality
2315 is known to be incomplete.
2317 You should say N unless you know you need this.
2319 source "drivers/pci/pcie/Kconfig"
2321 source "drivers/pci/Kconfig"
2323 # x86_64 have no ISA slots, but can have ISA-style DMA.
2325 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2328 Enables ISA-style DMA support for devices requiring such controllers.
2336 Find out whether you have ISA slots on your motherboard. ISA is the
2337 name of a bus system, i.e. the way the CPU talks to the other stuff
2338 inside your box. Other bus systems are PCI, EISA, MicroChannel
2339 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2340 newer boards don't support it. If you have ISA, say Y, otherwise N.
2346 The Extended Industry Standard Architecture (EISA) bus was
2347 developed as an open alternative to the IBM MicroChannel bus.
2349 The EISA bus provided some of the features of the IBM MicroChannel
2350 bus while maintaining backward compatibility with cards made for
2351 the older ISA bus. The EISA bus saw limited use between 1988 and
2352 1995 when it was made obsolete by the PCI bus.
2354 Say Y here if you are building a kernel for an EISA-based machine.
2358 source "drivers/eisa/Kconfig"
2361 tristate "NatSemi SCx200 support"
2363 This provides basic support for National Semiconductor's
2364 (now AMD's) Geode processors. The driver probes for the
2365 PCI-IDs of several on-chip devices, so its a good dependency
2366 for other scx200_* drivers.
2368 If compiled as a module, the driver is named scx200.
2370 config SCx200HR_TIMER
2371 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2375 This driver provides a clocksource built upon the on-chip
2376 27MHz high-resolution timer. Its also a workaround for
2377 NSC Geode SC-1100's buggy TSC, which loses time when the
2378 processor goes idle (as is done by the scheduler). The
2379 other workaround is idle=poll boot option.
2382 bool "One Laptop Per Child support"
2389 Add support for detecting the unique features of the OLPC
2393 bool "OLPC XO-1 Power Management"
2394 depends on OLPC && MFD_CS5535 && PM_SLEEP
2397 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2400 bool "OLPC XO-1 Real Time Clock"
2401 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2403 Add support for the XO-1 real time clock, which can be used as a
2404 programmable wakeup source.
2407 bool "OLPC XO-1 SCI extras"
2408 depends on OLPC && OLPC_XO1_PM
2414 Add support for SCI-based features of the OLPC XO-1 laptop:
2415 - EC-driven system wakeups
2419 - AC adapter status updates
2420 - Battery status updates
2422 config OLPC_XO15_SCI
2423 bool "OLPC XO-1.5 SCI extras"
2424 depends on OLPC && ACPI
2427 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2428 - EC-driven system wakeups
2429 - AC adapter status updates
2430 - Battery status updates
2433 bool "PCEngines ALIX System Support (LED setup)"
2436 This option enables system support for the PCEngines ALIX.
2437 At present this just sets up LEDs for GPIO control on
2438 ALIX2/3/6 boards. However, other system specific setup should
2441 Note: You must still enable the drivers for GPIO and LED support
2442 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2444 Note: You have to set alix.force=1 for boards with Award BIOS.
2447 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2450 This option enables system support for the Soekris Engineering net5501.
2453 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2457 This option enables system support for the Traverse Technologies GEOS.
2460 bool "Technologic Systems TS-5500 platform support"
2462 select CHECK_SIGNATURE
2466 This option enables system support for the Technologic Systems TS-5500.
2472 depends on CPU_SUP_AMD && PCI
2474 source "drivers/pcmcia/Kconfig"
2476 source "drivers/pci/hotplug/Kconfig"
2479 tristate "RapidIO support"
2483 If enabled this option will include drivers and the core
2484 infrastructure code to support RapidIO interconnect devices.
2486 source "drivers/rapidio/Kconfig"
2489 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2491 Firmwares often provide initial graphics framebuffers so the BIOS,
2492 bootloader or kernel can show basic video-output during boot for
2493 user-guidance and debugging. Historically, x86 used the VESA BIOS
2494 Extensions and EFI-framebuffers for this, which are mostly limited
2496 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2497 framebuffers so the new generic system-framebuffer drivers can be
2498 used on x86. If the framebuffer is not compatible with the generic
2499 modes, it is adverticed as fallback platform framebuffer so legacy
2500 drivers like efifb, vesafb and uvesafb can pick it up.
2501 If this option is not selected, all system framebuffers are always
2502 marked as fallback platform framebuffers as usual.
2504 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2505 not be able to pick up generic system framebuffers if this option
2506 is selected. You are highly encouraged to enable simplefb as
2507 replacement if you select this option. simplefb can correctly deal
2508 with generic system framebuffers. But you should still keep vesafb
2509 and others enabled as fallback if a system framebuffer is
2510 incompatible with simplefb.
2517 menu "Executable file formats / Emulations"
2519 source "fs/Kconfig.binfmt"
2521 config IA32_EMULATION
2522 bool "IA32 Emulation"
2525 select COMPAT_BINFMT_ELF
2528 Include code to run legacy 32-bit programs under a
2529 64-bit kernel. You should likely turn this on, unless you're
2530 100% sure that you don't have any 32-bit programs left.
2533 tristate "IA32 a.out support"
2534 depends on IA32_EMULATION
2536 Support old a.out binaries in the 32bit emulation.
2539 bool "x32 ABI for 64-bit mode"
2540 depends on X86_64 && IA32_EMULATION
2542 Include code to run binaries for the x32 native 32-bit ABI
2543 for 64-bit processors. An x32 process gets access to the
2544 full 64-bit register file and wide data path while leaving
2545 pointers at 32 bits for smaller memory footprint.
2547 You will need a recent binutils (2.22 or later) with
2548 elf32_x86_64 support enabled to compile a kernel with this
2553 depends on IA32_EMULATION || X86_X32
2554 select ARCH_WANT_OLD_COMPAT_IPC
2557 config COMPAT_FOR_U64_ALIGNMENT
2560 config SYSVIPC_COMPAT
2572 config HAVE_ATOMIC_IOMAP
2576 config X86_DEV_DMA_OPS
2578 depends on X86_64 || STA2X11
2580 config X86_DMA_REMAP
2588 source "net/Kconfig"
2590 source "drivers/Kconfig"
2592 source "drivers/firmware/Kconfig"
2596 source "arch/x86/Kconfig.debug"
2598 source "security/Kconfig"
2600 source "crypto/Kconfig"
2602 source "arch/x86/kvm/Kconfig"
2604 source "lib/Kconfig"