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_SG_CHAIN
32 select ARCH_HAVE_NMI_SAFE_CMPXCHG
33 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
34 select ARCH_MIGHT_HAVE_PC_PARPORT
35 select ARCH_MIGHT_HAVE_PC_SERIO
36 select ARCH_SUPPORTS_ATOMIC_RMW
37 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
38 select ARCH_SUPPORTS_INT128 if X86_64
39 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
40 select ARCH_USE_BUILTIN_BSWAP
41 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
42 select ARCH_USE_QUEUED_RWLOCKS
43 select ARCH_USE_QUEUED_SPINLOCKS
44 select ARCH_WANT_FRAME_POINTERS
45 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
46 select ARCH_WANT_OPTIONAL_GPIOLIB
47 select BUILDTIME_EXTABLE_SORT
49 select CLKSRC_I8253 if X86_32
50 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
51 select CLOCKSOURCE_WATCHDOG
52 select CLONE_BACKWARDS if X86_32
53 select COMPAT_OLD_SIGACTION if IA32_EMULATION
54 select DCACHE_WORD_ACCESS
55 select EDAC_ATOMIC_SCRUB
57 select GENERIC_CLOCKEVENTS
58 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
59 select GENERIC_CLOCKEVENTS_MIN_ADJUST
60 select GENERIC_CMOS_UPDATE
61 select GENERIC_CPU_AUTOPROBE
62 select GENERIC_EARLY_IOREMAP
63 select GENERIC_FIND_FIRST_BIT
65 select GENERIC_IRQ_PROBE
66 select GENERIC_IRQ_SHOW
67 select GENERIC_PENDING_IRQ if SMP
68 select GENERIC_SMP_IDLE_THREAD
69 select GENERIC_STRNCPY_FROM_USER
70 select GENERIC_STRNLEN_USER
71 select GENERIC_TIME_VSYSCALL
72 select HAVE_ACPI_APEI if ACPI
73 select HAVE_ACPI_APEI_NMI if ACPI
74 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
75 select HAVE_AOUT if X86_32
76 select HAVE_ARCH_AUDITSYSCALL
77 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
78 select HAVE_ARCH_JUMP_LABEL
79 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
81 select HAVE_ARCH_KMEMCHECK
82 select HAVE_ARCH_SECCOMP_FILTER
83 select HAVE_ARCH_SOFT_DIRTY if X86_64
84 select HAVE_ARCH_TRACEHOOK
85 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
86 select HAVE_BPF_JIT if X86_64
87 select HAVE_CC_STACKPROTECTOR
88 select HAVE_CMPXCHG_DOUBLE
89 select HAVE_CMPXCHG_LOCAL
90 select HAVE_CONTEXT_TRACKING if X86_64
91 select HAVE_C_RECORDMCOUNT
92 select HAVE_DEBUG_KMEMLEAK
93 select HAVE_DEBUG_STACKOVERFLOW
94 select HAVE_DMA_API_DEBUG
96 select HAVE_DMA_CONTIGUOUS
97 select HAVE_DYNAMIC_FTRACE
98 select HAVE_DYNAMIC_FTRACE_WITH_REGS
99 select HAVE_EFFICIENT_UNALIGNED_ACCESS
100 select HAVE_FENTRY if X86_64
101 select HAVE_FTRACE_MCOUNT_RECORD
102 select HAVE_FUNCTION_GRAPH_FP_TEST
103 select HAVE_FUNCTION_GRAPH_TRACER
104 select HAVE_FUNCTION_TRACER
105 select HAVE_GENERIC_DMA_COHERENT if X86_32
106 select HAVE_HW_BREAKPOINT
108 select HAVE_IOREMAP_PROT
109 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
110 select HAVE_IRQ_TIME_ACCOUNTING
111 select HAVE_KERNEL_BZIP2
112 select HAVE_KERNEL_GZIP
113 select HAVE_KERNEL_LZ4
114 select HAVE_KERNEL_LZMA
115 select HAVE_KERNEL_LZO
116 select HAVE_KERNEL_XZ
118 select HAVE_KPROBES_ON_FTRACE
119 select HAVE_KRETPROBES
121 select HAVE_LIVEPATCH if X86_64
123 select HAVE_MEMBLOCK_NODE_MAP
124 select HAVE_MIXED_BREAKPOINTS_REGS
126 select HAVE_OPTPROBES
127 select HAVE_PCSPKR_PLATFORM
128 select HAVE_PERF_EVENTS
129 select HAVE_PERF_EVENTS_NMI
130 select HAVE_PERF_REGS
131 select HAVE_PERF_USER_STACK_DUMP
132 select HAVE_REGS_AND_STACK_ACCESS_API
133 select HAVE_SYSCALL_TRACEPOINTS
134 select HAVE_UID16 if X86_32
135 select HAVE_UNSTABLE_SCHED_CLOCK
136 select HAVE_USER_RETURN_NOTIFIER
137 select IRQ_FORCED_THREADING
138 select MODULES_USE_ELF_RELA if X86_64
139 select MODULES_USE_ELF_REL if X86_32
140 select OLD_SIGACTION if X86_32
141 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
146 select SYSCTL_EXCEPTION_TRACE
147 select USER_STACKTRACE_SUPPORT
149 select X86_DEV_DMA_OPS if X86_64
150 select X86_FEATURE_NAMES if PROC_FS
152 config INSTRUCTION_DECODER
154 depends on KPROBES || PERF_EVENTS || UPROBES
156 config PERF_EVENTS_INTEL_UNCORE
158 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
162 default "elf32-i386" if X86_32
163 default "elf64-x86-64" if X86_64
165 config ARCH_DEFCONFIG
167 default "arch/x86/configs/i386_defconfig" if X86_32
168 default "arch/x86/configs/x86_64_defconfig" if X86_64
170 config LOCKDEP_SUPPORT
173 config STACKTRACE_SUPPORT
176 config HAVE_LATENCYTOP_SUPPORT
185 config NEED_DMA_MAP_STATE
187 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
189 config NEED_SG_DMA_LENGTH
192 config GENERIC_ISA_DMA
194 depends on ISA_DMA_API
199 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
201 config GENERIC_BUG_RELATIVE_POINTERS
204 config GENERIC_HWEIGHT
207 config ARCH_MAY_HAVE_PC_FDC
209 depends on ISA_DMA_API
211 config RWSEM_XCHGADD_ALGORITHM
214 config GENERIC_CALIBRATE_DELAY
217 config ARCH_HAS_CPU_RELAX
220 config ARCH_HAS_CACHE_LINE_SIZE
223 config HAVE_SETUP_PER_CPU_AREA
226 config NEED_PER_CPU_EMBED_FIRST_CHUNK
229 config NEED_PER_CPU_PAGE_FIRST_CHUNK
232 config ARCH_HIBERNATION_POSSIBLE
235 config ARCH_SUSPEND_POSSIBLE
238 config ARCH_WANT_HUGE_PMD_SHARE
241 config ARCH_WANT_GENERAL_HUGETLB
250 config ARCH_SUPPORTS_OPTIMIZED_INLINING
253 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
256 config HAVE_INTEL_TXT
258 depends on INTEL_IOMMU && ACPI
262 depends on X86_32 && SMP
266 depends on X86_64 && SMP
268 config X86_32_LAZY_GS
270 depends on X86_32 && !CC_STACKPROTECTOR
272 config ARCH_HWEIGHT_CFLAGS
274 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
275 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
277 config ARCH_SUPPORTS_UPROBES
280 config FIX_EARLYCON_MEM
283 config PGTABLE_LEVELS
289 source "init/Kconfig"
290 source "kernel/Kconfig.freezer"
292 menu "Processor type and features"
295 bool "DMA memory allocation support" if EXPERT
298 DMA memory allocation support allows devices with less than 32-bit
299 addressing to allocate within the first 16MB of address space.
300 Disable if no such devices will be used.
305 bool "Symmetric multi-processing support"
307 This enables support for systems with more than one CPU. If you have
308 a system with only one CPU, say N. If you have a system with more
311 If you say N here, the kernel will run on uni- and multiprocessor
312 machines, but will use only one CPU of a multiprocessor machine. If
313 you say Y here, the kernel will run on many, but not all,
314 uniprocessor machines. On a uniprocessor machine, the kernel
315 will run faster if you say N here.
317 Note that if you say Y here and choose architecture "586" or
318 "Pentium" under "Processor family", the kernel will not work on 486
319 architectures. Similarly, multiprocessor kernels for the "PPro"
320 architecture may not work on all Pentium based boards.
322 People using multiprocessor machines who say Y here should also say
323 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
324 Management" code will be disabled if you say Y here.
326 See also <file:Documentation/x86/i386/IO-APIC.txt>,
327 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
328 <http://www.tldp.org/docs.html#howto>.
330 If you don't know what to do here, say N.
332 config X86_FEATURE_NAMES
333 bool "Processor feature human-readable names" if EMBEDDED
336 This option compiles in a table of x86 feature bits and corresponding
337 names. This is required to support /proc/cpuinfo and a few kernel
338 messages. You can disable this to save space, at the expense of
339 making those few kernel messages show numeric feature bits instead.
344 bool "Support x2apic"
345 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
347 This enables x2apic support on CPUs that have this feature.
349 This allows 32-bit apic IDs (so it can support very large systems),
350 and accesses the local apic via MSRs not via mmio.
352 If you don't know what to do here, say N.
355 bool "Enable MPS table" if ACPI || SFI
357 depends on X86_LOCAL_APIC
359 For old smp systems that do not have proper acpi support. Newer systems
360 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
363 bool "Support for big SMP systems with more than 8 CPUs"
364 depends on X86_32 && SMP
366 This option is needed for the systems that have more than 8 CPUs
370 depends on X86_GOLDFISH
373 config X86_EXTENDED_PLATFORM
374 bool "Support for extended (non-PC) x86 platforms"
377 If you disable this option then the kernel will only support
378 standard PC platforms. (which covers the vast majority of
381 If you enable this option then you'll be able to select support
382 for the following (non-PC) 32 bit x86 platforms:
383 Goldfish (Android emulator)
386 SGI 320/540 (Visual Workstation)
387 STA2X11-based (e.g. Northville)
388 Moorestown MID devices
390 If you have one of these systems, or if you want to build a
391 generic distribution kernel, say Y here - otherwise say N.
395 config X86_EXTENDED_PLATFORM
396 bool "Support for extended (non-PC) x86 platforms"
399 If you disable this option then the kernel will only support
400 standard PC platforms. (which covers the vast majority of
403 If you enable this option then you'll be able to select support
404 for the following (non-PC) 64 bit x86 platforms:
409 If you have one of these systems, or if you want to build a
410 generic distribution kernel, say Y here - otherwise say N.
412 # This is an alphabetically sorted list of 64 bit extended platforms
413 # Please maintain the alphabetic order if and when there are additions
415 bool "Numascale NumaChip"
417 depends on X86_EXTENDED_PLATFORM
420 depends on X86_X2APIC
421 depends on PCI_MMCONFIG
423 Adds support for Numascale NumaChip large-SMP systems. Needed to
424 enable more than ~168 cores.
425 If you don't have one of these, you should say N here.
429 select HYPERVISOR_GUEST
431 depends on X86_64 && PCI
432 depends on X86_EXTENDED_PLATFORM
435 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
436 supposed to run on these EM64T-based machines. Only choose this option
437 if you have one of these machines.
440 bool "SGI Ultraviolet"
442 depends on X86_EXTENDED_PLATFORM
444 depends on X86_X2APIC
447 This option is needed in order to support SGI Ultraviolet systems.
448 If you don't have one of these, you should say N here.
450 # Following is an alphabetically sorted list of 32 bit extended platforms
451 # Please maintain the alphabetic order if and when there are additions
454 bool "Goldfish (Virtual Platform)"
455 depends on X86_EXTENDED_PLATFORM
457 Enable support for the Goldfish virtual platform used primarily
458 for Android development. Unless you are building for the Android
459 Goldfish emulator say N here.
462 bool "CE4100 TV platform"
464 depends on PCI_GODIRECT
465 depends on X86_IO_APIC
467 depends on X86_EXTENDED_PLATFORM
468 select X86_REBOOTFIXUPS
470 select OF_EARLY_FLATTREE
472 Select for the Intel CE media processor (CE4100) SOC.
473 This option compiles in support for the CE4100 SOC for settop
474 boxes and media devices.
477 bool "Intel MID platform support"
479 depends on X86_EXTENDED_PLATFORM
480 depends on X86_PLATFORM_DEVICES
483 depends on X86_IO_APIC
489 select MFD_INTEL_MSIC
491 Select to build a kernel capable of supporting Intel MID (Mobile
492 Internet Device) platform systems which do not have the PCI legacy
493 interfaces. If you are building for a PC class system say N here.
495 Intel MID platforms are based on an Intel processor and chipset which
496 consume less power than most of the x86 derivatives.
498 config X86_INTEL_QUARK
499 bool "Intel Quark platform support"
501 depends on X86_EXTENDED_PLATFORM
502 depends on X86_PLATFORM_DEVICES
506 depends on X86_IO_APIC
511 Select to include support for Quark X1000 SoC.
512 Say Y here if you have a Quark based system such as the Arduino
513 compatible Intel Galileo.
515 config X86_INTEL_LPSS
516 bool "Intel Low Power Subsystem Support"
521 Select to build support for Intel Low Power Subsystem such as
522 found on Intel Lynxpoint PCH. Selecting this option enables
523 things like clock tree (common clock framework) and pincontrol
524 which are needed by the LPSS peripheral drivers.
526 config X86_AMD_PLATFORM_DEVICE
527 bool "AMD ACPI2Platform devices support"
532 Select to interpret AMD specific ACPI device to platform device
533 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
534 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
535 implemented under PINCTRL subsystem.
538 tristate "Intel SoC IOSF Sideband support for SoC platforms"
541 This option enables sideband register access support for Intel SoC
542 platforms. On these platforms the IOSF sideband is used in lieu of
543 MSR's for some register accesses, mostly but not limited to thermal
544 and power. Drivers may query the availability of this device to
545 determine if they need the sideband in order to work on these
546 platforms. The sideband is available on the following SoC products.
547 This list is not meant to be exclusive.
552 You should say Y if you are running a kernel on one of these SoC's.
554 config IOSF_MBI_DEBUG
555 bool "Enable IOSF sideband access through debugfs"
556 depends on IOSF_MBI && DEBUG_FS
558 Select this option to expose the IOSF sideband access registers (MCR,
559 MDR, MCRX) through debugfs to write and read register information from
560 different units on the SoC. This is most useful for obtaining device
561 state information for debug and analysis. As this is a general access
562 mechanism, users of this option would have specific knowledge of the
563 device they want to access.
565 If you don't require the option or are in doubt, say N.
568 bool "RDC R-321x SoC"
570 depends on X86_EXTENDED_PLATFORM
572 select X86_REBOOTFIXUPS
574 This option is needed for RDC R-321x system-on-chip, also known
576 If you don't have one of these chips, you should say N here.
578 config X86_32_NON_STANDARD
579 bool "Support non-standard 32-bit SMP architectures"
580 depends on X86_32 && SMP
581 depends on X86_EXTENDED_PLATFORM
583 This option compiles in the bigsmp and STA2X11 default
584 subarchitectures. It is intended for a generic binary
585 kernel. If you select them all, kernel will probe it one by
586 one and will fallback to default.
588 # Alphabetically sorted list of Non standard 32 bit platforms
590 config X86_SUPPORTS_MEMORY_FAILURE
592 # MCE code calls memory_failure():
594 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
595 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
596 depends on X86_64 || !SPARSEMEM
597 select ARCH_SUPPORTS_MEMORY_FAILURE
600 bool "STA2X11 Companion Chip Support"
601 depends on X86_32_NON_STANDARD && PCI
602 select X86_DEV_DMA_OPS
606 select ARCH_REQUIRE_GPIOLIB
609 This adds support for boards based on the STA2X11 IO-Hub,
610 a.k.a. "ConneXt". The chip is used in place of the standard
611 PC chipset, so all "standard" peripherals are missing. If this
612 option is selected the kernel will still be able to boot on
613 standard PC machines.
616 tristate "Eurobraille/Iris poweroff module"
619 The Iris machines from EuroBraille do not have APM or ACPI support
620 to shut themselves down properly. A special I/O sequence is
621 needed to do so, which is what this module does at
624 This is only for Iris machines from EuroBraille.
628 config SCHED_OMIT_FRAME_POINTER
630 prompt "Single-depth WCHAN output"
633 Calculate simpler /proc/<PID>/wchan values. If this option
634 is disabled then wchan values will recurse back to the
635 caller function. This provides more accurate wchan values,
636 at the expense of slightly more scheduling overhead.
638 If in doubt, say "Y".
640 menuconfig HYPERVISOR_GUEST
641 bool "Linux guest support"
643 Say Y here to enable options for running Linux under various hyper-
644 visors. This option enables basic hypervisor detection and platform
647 If you say N, all options in this submenu will be skipped and
648 disabled, and Linux guest support won't be built in.
653 bool "Enable paravirtualization code"
655 This changes the kernel so it can modify itself when it is run
656 under a hypervisor, potentially improving performance significantly
657 over full virtualization. However, when run without a hypervisor
658 the kernel is theoretically slower and slightly larger.
660 config PARAVIRT_DEBUG
661 bool "paravirt-ops debugging"
662 depends on PARAVIRT && DEBUG_KERNEL
664 Enable to debug paravirt_ops internals. Specifically, BUG if
665 a paravirt_op is missing when it is called.
667 config PARAVIRT_SPINLOCKS
668 bool "Paravirtualization layer for spinlocks"
669 depends on PARAVIRT && SMP
670 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
672 Paravirtualized spinlocks allow a pvops backend to replace the
673 spinlock implementation with something virtualization-friendly
674 (for example, block the virtual CPU rather than spinning).
676 It has a minimal impact on native kernels and gives a nice performance
677 benefit on paravirtualized KVM / Xen kernels.
679 If you are unsure how to answer this question, answer Y.
681 source "arch/x86/xen/Kconfig"
684 bool "KVM Guest support (including kvmclock)"
686 select PARAVIRT_CLOCK
689 This option enables various optimizations for running under the KVM
690 hypervisor. It includes a paravirtualized clock, so that instead
691 of relying on a PIT (or probably other) emulation by the
692 underlying device model, the host provides the guest with
693 timing infrastructure such as time of day, and system time
696 bool "Enable debug information for KVM Guests in debugfs"
697 depends on KVM_GUEST && DEBUG_FS
700 This option enables collection of various statistics for KVM guest.
701 Statistics are displayed in debugfs filesystem. Enabling this option
702 may incur significant overhead.
704 source "arch/x86/lguest/Kconfig"
706 config PARAVIRT_TIME_ACCOUNTING
707 bool "Paravirtual steal time accounting"
711 Select this option to enable fine granularity task steal time
712 accounting. Time spent executing other tasks in parallel with
713 the current vCPU is discounted from the vCPU power. To account for
714 that, there can be a small performance impact.
716 If in doubt, say N here.
718 config PARAVIRT_CLOCK
721 endif #HYPERVISOR_GUEST
726 source "arch/x86/Kconfig.cpu"
730 prompt "HPET Timer Support" if X86_32
732 Use the IA-PC HPET (High Precision Event Timer) to manage
733 time in preference to the PIT and RTC, if a HPET is
735 HPET is the next generation timer replacing legacy 8254s.
736 The HPET provides a stable time base on SMP
737 systems, unlike the TSC, but it is more expensive to access,
738 as it is off-chip. You can find the HPET spec at
739 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
741 You can safely choose Y here. However, HPET will only be
742 activated if the platform and the BIOS support this feature.
743 Otherwise the 8254 will be used for timing services.
745 Choose N to continue using the legacy 8254 timer.
747 config HPET_EMULATE_RTC
749 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
752 def_bool y if X86_INTEL_MID
753 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
755 depends on X86_INTEL_MID && SFI
757 APB timer is the replacement for 8254, HPET on X86 MID platforms.
758 The APBT provides a stable time base on SMP
759 systems, unlike the TSC, but it is more expensive to access,
760 as it is off-chip. APB timers are always running regardless of CPU
761 C states, they are used as per CPU clockevent device when possible.
763 # Mark as expert because too many people got it wrong.
764 # The code disables itself when not needed.
767 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
768 bool "Enable DMI scanning" if EXPERT
770 Enabled scanning of DMI to identify machine quirks. Say Y
771 here unless you have verified that your setup is not
772 affected by entries in the DMI blacklist. Required by PNP
776 bool "Old AMD GART IOMMU support"
778 depends on X86_64 && PCI && AMD_NB
780 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
781 GART based hardware IOMMUs.
783 The GART supports full DMA access for devices with 32-bit access
784 limitations, on systems with more than 3 GB. This is usually needed
785 for USB, sound, many IDE/SATA chipsets and some other devices.
787 Newer systems typically have a modern AMD IOMMU, supported via
788 the CONFIG_AMD_IOMMU=y config option.
790 In normal configurations this driver is only active when needed:
791 there's more than 3 GB of memory and the system contains a
792 32-bit limited device.
797 bool "IBM Calgary IOMMU support"
799 depends on X86_64 && PCI
801 Support for hardware IOMMUs in IBM's xSeries x366 and x460
802 systems. Needed to run systems with more than 3GB of memory
803 properly with 32-bit PCI devices that do not support DAC
804 (Double Address Cycle). Calgary also supports bus level
805 isolation, where all DMAs pass through the IOMMU. This
806 prevents them from going anywhere except their intended
807 destination. This catches hard-to-find kernel bugs and
808 mis-behaving drivers and devices that do not use the DMA-API
809 properly to set up their DMA buffers. The IOMMU can be
810 turned off at boot time with the iommu=off parameter.
811 Normally the kernel will make the right choice by itself.
814 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
816 prompt "Should Calgary be enabled by default?"
817 depends on CALGARY_IOMMU
819 Should Calgary be enabled by default? if you choose 'y', Calgary
820 will be used (if it exists). If you choose 'n', Calgary will not be
821 used even if it exists. If you choose 'n' and would like to use
822 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
825 # need this always selected by IOMMU for the VIA workaround
829 Support for software bounce buffers used on x86-64 systems
830 which don't have a hardware IOMMU. Using this PCI devices
831 which can only access 32-bits of memory can be used on systems
832 with more than 3 GB of memory.
837 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
840 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
841 depends on X86_64 && SMP && DEBUG_KERNEL
842 select CPUMASK_OFFSTACK
844 Enable maximum number of CPUS and NUMA Nodes for this architecture.
848 int "Maximum number of CPUs" if SMP && !MAXSMP
849 range 2 8 if SMP && X86_32 && !X86_BIGSMP
850 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
851 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
853 default "8192" if MAXSMP
854 default "32" if SMP && X86_BIGSMP
855 default "8" if SMP && X86_32
858 This allows you to specify the maximum number of CPUs which this
859 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
860 supported value is 8192, otherwise the maximum value is 512. The
861 minimum value which makes sense is 2.
863 This is purely to save memory - each supported CPU adds
864 approximately eight kilobytes to the kernel image.
867 bool "SMT (Hyperthreading) scheduler support"
870 SMT scheduler support improves the CPU scheduler's decision making
871 when dealing with Intel Pentium 4 chips with HyperThreading at a
872 cost of slightly increased overhead in some places. If unsure say
877 prompt "Multi-core scheduler support"
880 Multi-core scheduler support improves the CPU scheduler's decision
881 making when dealing with multi-core CPU chips at a cost of slightly
882 increased overhead in some places. If unsure say N here.
884 source "kernel/Kconfig.preempt"
888 depends on !SMP && X86_LOCAL_APIC
891 bool "Local APIC support on uniprocessors" if !PCI_MSI
893 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
895 A local APIC (Advanced Programmable Interrupt Controller) is an
896 integrated interrupt controller in the CPU. If you have a single-CPU
897 system which has a processor with a local APIC, you can say Y here to
898 enable and use it. If you say Y here even though your machine doesn't
899 have a local APIC, then the kernel will still run with no slowdown at
900 all. The local APIC supports CPU-generated self-interrupts (timer,
901 performance counters), and the NMI watchdog which detects hard
905 bool "IO-APIC support on uniprocessors"
906 depends on X86_UP_APIC
908 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
909 SMP-capable replacement for PC-style interrupt controllers. Most
910 SMP systems and many recent uniprocessor systems have one.
912 If you have a single-CPU system with an IO-APIC, you can say Y here
913 to use it. If you say Y here even though your machine doesn't have
914 an IO-APIC, then the kernel will still run with no slowdown at all.
916 config X86_LOCAL_APIC
918 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
919 select IRQ_DOMAIN_HIERARCHY
920 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
924 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
926 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
927 bool "Reroute for broken boot IRQs"
928 depends on X86_IO_APIC
930 This option enables a workaround that fixes a source of
931 spurious interrupts. This is recommended when threaded
932 interrupt handling is used on systems where the generation of
933 superfluous "boot interrupts" cannot be disabled.
935 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
936 entry in the chipset's IO-APIC is masked (as, e.g. the RT
937 kernel does during interrupt handling). On chipsets where this
938 boot IRQ generation cannot be disabled, this workaround keeps
939 the original IRQ line masked so that only the equivalent "boot
940 IRQ" is delivered to the CPUs. The workaround also tells the
941 kernel to set up the IRQ handler on the boot IRQ line. In this
942 way only one interrupt is delivered to the kernel. Otherwise
943 the spurious second interrupt may cause the kernel to bring
944 down (vital) interrupt lines.
946 Only affects "broken" chipsets. Interrupt sharing may be
947 increased on these systems.
950 bool "Machine Check / overheating reporting"
953 Machine Check support allows the processor to notify the
954 kernel if it detects a problem (e.g. overheating, data corruption).
955 The action the kernel takes depends on the severity of the problem,
956 ranging from warning messages to halting the machine.
960 prompt "Intel MCE features"
961 depends on X86_MCE && X86_LOCAL_APIC
963 Additional support for intel specific MCE features such as
968 prompt "AMD MCE features"
969 depends on X86_MCE && X86_LOCAL_APIC
971 Additional support for AMD specific MCE features such as
972 the DRAM Error Threshold.
974 config X86_ANCIENT_MCE
975 bool "Support for old Pentium 5 / WinChip machine checks"
976 depends on X86_32 && X86_MCE
978 Include support for machine check handling on old Pentium 5 or WinChip
979 systems. These typically need to be enabled explicitly on the command
982 config X86_MCE_THRESHOLD
983 depends on X86_MCE_AMD || X86_MCE_INTEL
986 config X86_MCE_INJECT
988 tristate "Machine check injector support"
990 Provide support for injecting machine checks for testing purposes.
991 If you don't know what a machine check is and you don't do kernel
992 QA it is safe to say n.
994 config X86_THERMAL_VECTOR
996 depends on X86_MCE_INTEL
999 bool "Enable VM86 support" if EXPERT
1003 This option is required by programs like DOSEMU to run
1004 16-bit real mode legacy code on x86 processors. It also may
1005 be needed by software like XFree86 to initialize some video
1006 cards via BIOS. Disabling this option saves about 6K.
1009 bool "Enable support for 16-bit segments" if EXPERT
1012 This option is required by programs like Wine to run 16-bit
1013 protected mode legacy code on x86 processors. Disabling
1014 this option saves about 300 bytes on i386, or around 6K text
1015 plus 16K runtime memory on x86-64,
1019 depends on X86_16BIT && X86_32
1023 depends on X86_16BIT && X86_64
1025 config X86_VSYSCALL_EMULATION
1026 bool "Enable vsyscall emulation" if EXPERT
1030 This enables emulation of the legacy vsyscall page. Disabling
1031 it is roughly equivalent to booting with vsyscall=none, except
1032 that it will also disable the helpful warning if a program
1033 tries to use a vsyscall. With this option set to N, offending
1034 programs will just segfault, citing addresses of the form
1037 This option is required by many programs built before 2013, and
1038 care should be used even with newer programs if set to N.
1040 Disabling this option saves about 7K of kernel size and
1041 possibly 4K of additional runtime pagetable memory.
1044 tristate "Toshiba Laptop support"
1047 This adds a driver to safely access the System Management Mode of
1048 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1049 not work on models with a Phoenix BIOS. The System Management Mode
1050 is used to set the BIOS and power saving options on Toshiba portables.
1052 For information on utilities to make use of this driver see the
1053 Toshiba Linux utilities web site at:
1054 <http://www.buzzard.org.uk/toshiba/>.
1056 Say Y if you intend to run this kernel on a Toshiba portable.
1060 tristate "Dell i8k legacy laptop support"
1062 select SENSORS_DELL_SMM
1064 This option enables legacy /proc/i8k userspace interface in hwmon
1065 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1066 temperature and allows controlling fan speeds of Dell laptops via
1067 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1068 it reports also power and hotkey status. For fan speed control is
1069 needed userspace package i8kutils.
1071 Say Y if you intend to run this kernel on old Dell laptops or want to
1072 use userspace package i8kutils.
1075 config X86_REBOOTFIXUPS
1076 bool "Enable X86 board specific fixups for reboot"
1079 This enables chipset and/or board specific fixups to be done
1080 in order to get reboot to work correctly. This is only needed on
1081 some combinations of hardware and BIOS. The symptom, for which
1082 this config is intended, is when reboot ends with a stalled/hung
1085 Currently, the only fixup is for the Geode machines using
1086 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1088 Say Y if you want to enable the fixup. Currently, it's safe to
1089 enable this option even if you don't need it.
1093 tristate "CPU microcode loading support"
1094 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1098 If you say Y here, you will be able to update the microcode on
1099 certain Intel and AMD processors. The Intel support is for the
1100 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1101 Xeon etc. The AMD support is for families 0x10 and later. You will
1102 obviously need the actual microcode binary data itself which is not
1103 shipped with the Linux kernel.
1105 This option selects the general module only, you need to select
1106 at least one vendor specific module as well.
1108 To compile this driver as a module, choose M here: the module
1109 will be called microcode.
1111 config MICROCODE_INTEL
1112 bool "Intel microcode loading support"
1113 depends on MICROCODE
1117 This options enables microcode patch loading support for Intel
1120 For the current Intel microcode data package go to
1121 <https://downloadcenter.intel.com> and search for
1122 'Linux Processor Microcode Data File'.
1124 config MICROCODE_AMD
1125 bool "AMD microcode loading support"
1126 depends on MICROCODE
1129 If you select this option, microcode patch loading support for AMD
1130 processors will be enabled.
1132 config MICROCODE_OLD_INTERFACE
1134 depends on MICROCODE
1136 config MICROCODE_INTEL_EARLY
1139 config MICROCODE_AMD_EARLY
1142 config MICROCODE_EARLY
1143 bool "Early load microcode"
1144 depends on MICROCODE=y && BLK_DEV_INITRD
1145 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1146 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1149 This option provides functionality to read additional microcode data
1150 at the beginning of initrd image. The data tells kernel to load
1151 microcode to CPU's as early as possible. No functional change if no
1152 microcode data is glued to the initrd, therefore it's safe to say Y.
1155 tristate "/dev/cpu/*/msr - Model-specific register support"
1157 This device gives privileged processes access to the x86
1158 Model-Specific Registers (MSRs). It is a character device with
1159 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1160 MSR accesses are directed to a specific CPU on multi-processor
1164 tristate "/dev/cpu/*/cpuid - CPU information support"
1166 This device gives processes access to the x86 CPUID instruction to
1167 be executed on a specific processor. It is a character device
1168 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1172 prompt "High Memory Support"
1179 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1180 However, the address space of 32-bit x86 processors is only 4
1181 Gigabytes large. That means that, if you have a large amount of
1182 physical memory, not all of it can be "permanently mapped" by the
1183 kernel. The physical memory that's not permanently mapped is called
1186 If you are compiling a kernel which will never run on a machine with
1187 more than 1 Gigabyte total physical RAM, answer "off" here (default
1188 choice and suitable for most users). This will result in a "3GB/1GB"
1189 split: 3GB are mapped so that each process sees a 3GB virtual memory
1190 space and the remaining part of the 4GB virtual memory space is used
1191 by the kernel to permanently map as much physical memory as
1194 If the machine has between 1 and 4 Gigabytes physical RAM, then
1197 If more than 4 Gigabytes is used then answer "64GB" here. This
1198 selection turns Intel PAE (Physical Address Extension) mode on.
1199 PAE implements 3-level paging on IA32 processors. PAE is fully
1200 supported by Linux, PAE mode is implemented on all recent Intel
1201 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1202 then the kernel will not boot on CPUs that don't support PAE!
1204 The actual amount of total physical memory will either be
1205 auto detected or can be forced by using a kernel command line option
1206 such as "mem=256M". (Try "man bootparam" or see the documentation of
1207 your boot loader (lilo or loadlin) about how to pass options to the
1208 kernel at boot time.)
1210 If unsure, say "off".
1215 Select this if you have a 32-bit processor and between 1 and 4
1216 gigabytes of physical RAM.
1223 Select this if you have a 32-bit processor and more than 4
1224 gigabytes of physical RAM.
1229 prompt "Memory split" if EXPERT
1233 Select the desired split between kernel and user memory.
1235 If the address range available to the kernel is less than the
1236 physical memory installed, the remaining memory will be available
1237 as "high memory". Accessing high memory is a little more costly
1238 than low memory, as it needs to be mapped into the kernel first.
1239 Note that increasing the kernel address space limits the range
1240 available to user programs, making the address space there
1241 tighter. Selecting anything other than the default 3G/1G split
1242 will also likely make your kernel incompatible with binary-only
1245 If you are not absolutely sure what you are doing, leave this
1249 bool "3G/1G user/kernel split"
1250 config VMSPLIT_3G_OPT
1252 bool "3G/1G user/kernel split (for full 1G low memory)"
1254 bool "2G/2G user/kernel split"
1255 config VMSPLIT_2G_OPT
1257 bool "2G/2G user/kernel split (for full 2G low memory)"
1259 bool "1G/3G user/kernel split"
1264 default 0xB0000000 if VMSPLIT_3G_OPT
1265 default 0x80000000 if VMSPLIT_2G
1266 default 0x78000000 if VMSPLIT_2G_OPT
1267 default 0x40000000 if VMSPLIT_1G
1273 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1276 bool "PAE (Physical Address Extension) Support"
1277 depends on X86_32 && !HIGHMEM4G
1279 PAE is required for NX support, and furthermore enables
1280 larger swapspace support for non-overcommit purposes. It
1281 has the cost of more pagetable lookup overhead, and also
1282 consumes more pagetable space per process.
1284 config ARCH_PHYS_ADDR_T_64BIT
1286 depends on X86_64 || X86_PAE
1288 config ARCH_DMA_ADDR_T_64BIT
1290 depends on X86_64 || HIGHMEM64G
1292 config X86_DIRECT_GBPAGES
1294 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1296 Certain kernel features effectively disable kernel
1297 linear 1 GB mappings (even if the CPU otherwise
1298 supports them), so don't confuse the user by printing
1299 that we have them enabled.
1301 # Common NUMA Features
1303 bool "Numa Memory Allocation and Scheduler Support"
1305 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1306 default y if X86_BIGSMP
1308 Enable NUMA (Non Uniform Memory Access) support.
1310 The kernel will try to allocate memory used by a CPU on the
1311 local memory controller of the CPU and add some more
1312 NUMA awareness to the kernel.
1314 For 64-bit this is recommended if the system is Intel Core i7
1315 (or later), AMD Opteron, or EM64T NUMA.
1317 For 32-bit this is only needed if you boot a 32-bit
1318 kernel on a 64-bit NUMA platform.
1320 Otherwise, you should say N.
1324 prompt "Old style AMD Opteron NUMA detection"
1325 depends on X86_64 && NUMA && PCI
1327 Enable AMD NUMA node topology detection. You should say Y here if
1328 you have a multi processor AMD system. This uses an old method to
1329 read the NUMA configuration directly from the builtin Northbridge
1330 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1331 which also takes priority if both are compiled in.
1333 config X86_64_ACPI_NUMA
1335 prompt "ACPI NUMA detection"
1336 depends on X86_64 && NUMA && ACPI && PCI
1339 Enable ACPI SRAT based node topology detection.
1341 # Some NUMA nodes have memory ranges that span
1342 # other nodes. Even though a pfn is valid and
1343 # between a node's start and end pfns, it may not
1344 # reside on that node. See memmap_init_zone()
1346 config NODES_SPAN_OTHER_NODES
1348 depends on X86_64_ACPI_NUMA
1351 bool "NUMA emulation"
1354 Enable NUMA emulation. A flat machine will be split
1355 into virtual nodes when booted with "numa=fake=N", where N is the
1356 number of nodes. This is only useful for debugging.
1359 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1361 default "10" if MAXSMP
1362 default "6" if X86_64
1364 depends on NEED_MULTIPLE_NODES
1366 Specify the maximum number of NUMA Nodes available on the target
1367 system. Increases memory reserved to accommodate various tables.
1369 config ARCH_HAVE_MEMORY_PRESENT
1371 depends on X86_32 && DISCONTIGMEM
1373 config NEED_NODE_MEMMAP_SIZE
1375 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1377 config ARCH_FLATMEM_ENABLE
1379 depends on X86_32 && !NUMA
1381 config ARCH_DISCONTIGMEM_ENABLE
1383 depends on NUMA && X86_32
1385 config ARCH_DISCONTIGMEM_DEFAULT
1387 depends on NUMA && X86_32
1389 config ARCH_SPARSEMEM_ENABLE
1391 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1392 select SPARSEMEM_STATIC if X86_32
1393 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1395 config ARCH_SPARSEMEM_DEFAULT
1399 config ARCH_SELECT_MEMORY_MODEL
1401 depends on ARCH_SPARSEMEM_ENABLE
1403 config ARCH_MEMORY_PROBE
1404 bool "Enable sysfs memory/probe interface"
1405 depends on X86_64 && MEMORY_HOTPLUG
1407 This option enables a sysfs memory/probe interface for testing.
1408 See Documentation/memory-hotplug.txt for more information.
1409 If you are unsure how to answer this question, answer N.
1411 config ARCH_PROC_KCORE_TEXT
1413 depends on X86_64 && PROC_KCORE
1415 config ILLEGAL_POINTER_VALUE
1418 default 0xdead000000000000 if X86_64
1422 config X86_PMEM_LEGACY
1423 bool "Support non-standard NVDIMMs and ADR protected memory"
1424 depends on PHYS_ADDR_T_64BIT
1428 Treat memory marked using the non-standard e820 type of 12 as used
1429 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1430 The kernel will offer these regions to the 'pmem' driver so
1431 they can be used for persistent storage.
1436 bool "Allocate 3rd-level pagetables from highmem"
1439 The VM uses one page table entry for each page of physical memory.
1440 For systems with a lot of RAM, this can be wasteful of precious
1441 low memory. Setting this option will put user-space page table
1442 entries in high memory.
1444 config X86_CHECK_BIOS_CORRUPTION
1445 bool "Check for low memory corruption"
1447 Periodically check for memory corruption in low memory, which
1448 is suspected to be caused by BIOS. Even when enabled in the
1449 configuration, it is disabled at runtime. Enable it by
1450 setting "memory_corruption_check=1" on the kernel command
1451 line. By default it scans the low 64k of memory every 60
1452 seconds; see the memory_corruption_check_size and
1453 memory_corruption_check_period parameters in
1454 Documentation/kernel-parameters.txt to adjust this.
1456 When enabled with the default parameters, this option has
1457 almost no overhead, as it reserves a relatively small amount
1458 of memory and scans it infrequently. It both detects corruption
1459 and prevents it from affecting the running system.
1461 It is, however, intended as a diagnostic tool; if repeatable
1462 BIOS-originated corruption always affects the same memory,
1463 you can use memmap= to prevent the kernel from using that
1466 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1467 bool "Set the default setting of memory_corruption_check"
1468 depends on X86_CHECK_BIOS_CORRUPTION
1471 Set whether the default state of memory_corruption_check is
1474 config X86_RESERVE_LOW
1475 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1479 Specify the amount of low memory to reserve for the BIOS.
1481 The first page contains BIOS data structures that the kernel
1482 must not use, so that page must always be reserved.
1484 By default we reserve the first 64K of physical RAM, as a
1485 number of BIOSes are known to corrupt that memory range
1486 during events such as suspend/resume or monitor cable
1487 insertion, so it must not be used by the kernel.
1489 You can set this to 4 if you are absolutely sure that you
1490 trust the BIOS to get all its memory reservations and usages
1491 right. If you know your BIOS have problems beyond the
1492 default 64K area, you can set this to 640 to avoid using the
1493 entire low memory range.
1495 If you have doubts about the BIOS (e.g. suspend/resume does
1496 not work or there's kernel crashes after certain hardware
1497 hotplug events) then you might want to enable
1498 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1499 typical corruption patterns.
1501 Leave this to the default value of 64 if you are unsure.
1503 config MATH_EMULATION
1505 prompt "Math emulation" if X86_32
1507 Linux can emulate a math coprocessor (used for floating point
1508 operations) if you don't have one. 486DX and Pentium processors have
1509 a math coprocessor built in, 486SX and 386 do not, unless you added
1510 a 487DX or 387, respectively. (The messages during boot time can
1511 give you some hints here ["man dmesg"].) Everyone needs either a
1512 coprocessor or this emulation.
1514 If you don't have a math coprocessor, you need to say Y here; if you
1515 say Y here even though you have a coprocessor, the coprocessor will
1516 be used nevertheless. (This behavior can be changed with the kernel
1517 command line option "no387", which comes handy if your coprocessor
1518 is broken. Try "man bootparam" or see the documentation of your boot
1519 loader (lilo or loadlin) about how to pass options to the kernel at
1520 boot time.) This means that it is a good idea to say Y here if you
1521 intend to use this kernel on different machines.
1523 More information about the internals of the Linux math coprocessor
1524 emulation can be found in <file:arch/x86/math-emu/README>.
1526 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1527 kernel, it won't hurt.
1531 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1533 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1534 the Memory Type Range Registers (MTRRs) may be used to control
1535 processor access to memory ranges. This is most useful if you have
1536 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1537 allows bus write transfers to be combined into a larger transfer
1538 before bursting over the PCI/AGP bus. This can increase performance
1539 of image write operations 2.5 times or more. Saying Y here creates a
1540 /proc/mtrr file which may be used to manipulate your processor's
1541 MTRRs. Typically the X server should use this.
1543 This code has a reasonably generic interface so that similar
1544 control registers on other processors can be easily supported
1547 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1548 Registers (ARRs) which provide a similar functionality to MTRRs. For
1549 these, the ARRs are used to emulate the MTRRs.
1550 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1551 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1552 write-combining. All of these processors are supported by this code
1553 and it makes sense to say Y here if you have one of them.
1555 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1556 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1557 can lead to all sorts of problems, so it's good to say Y here.
1559 You can safely say Y even if your machine doesn't have MTRRs, you'll
1560 just add about 9 KB to your kernel.
1562 See <file:Documentation/x86/mtrr.txt> for more information.
1564 config MTRR_SANITIZER
1566 prompt "MTRR cleanup support"
1569 Convert MTRR layout from continuous to discrete, so X drivers can
1570 add writeback entries.
1572 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1573 The largest mtrr entry size for a continuous block can be set with
1578 config MTRR_SANITIZER_ENABLE_DEFAULT
1579 int "MTRR cleanup enable value (0-1)"
1582 depends on MTRR_SANITIZER
1584 Enable mtrr cleanup default value
1586 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1587 int "MTRR cleanup spare reg num (0-7)"
1590 depends on MTRR_SANITIZER
1592 mtrr cleanup spare entries default, it can be changed via
1593 mtrr_spare_reg_nr=N on the kernel command line.
1597 prompt "x86 PAT support" if EXPERT
1600 Use PAT attributes to setup page level cache control.
1602 PATs are the modern equivalents of MTRRs and are much more
1603 flexible than MTRRs.
1605 Say N here if you see bootup problems (boot crash, boot hang,
1606 spontaneous reboots) or a non-working video driver.
1610 config ARCH_USES_PG_UNCACHED
1616 prompt "x86 architectural random number generator" if EXPERT
1618 Enable the x86 architectural RDRAND instruction
1619 (Intel Bull Mountain technology) to generate random numbers.
1620 If supported, this is a high bandwidth, cryptographically
1621 secure hardware random number generator.
1625 prompt "Supervisor Mode Access Prevention" if EXPERT
1627 Supervisor Mode Access Prevention (SMAP) is a security
1628 feature in newer Intel processors. There is a small
1629 performance cost if this enabled and turned on; there is
1630 also a small increase in the kernel size if this is enabled.
1634 config X86_INTEL_MPX
1635 prompt "Intel MPX (Memory Protection Extensions)"
1637 depends on CPU_SUP_INTEL
1639 MPX provides hardware features that can be used in
1640 conjunction with compiler-instrumented code to check
1641 memory references. It is designed to detect buffer
1642 overflow or underflow bugs.
1644 This option enables running applications which are
1645 instrumented or otherwise use MPX. It does not use MPX
1646 itself inside the kernel or to protect the kernel
1647 against bad memory references.
1649 Enabling this option will make the kernel larger:
1650 ~8k of kernel text and 36 bytes of data on a 64-bit
1651 defconfig. It adds a long to the 'mm_struct' which
1652 will increase the kernel memory overhead of each
1653 process and adds some branches to paths used during
1654 exec() and munmap().
1656 For details, see Documentation/x86/intel_mpx.txt
1661 bool "EFI runtime service support"
1664 select EFI_RUNTIME_WRAPPERS
1666 This enables the kernel to use EFI runtime services that are
1667 available (such as the EFI variable services).
1669 This option is only useful on systems that have EFI firmware.
1670 In addition, you should use the latest ELILO loader available
1671 at <http://elilo.sourceforge.net> in order to take advantage
1672 of EFI runtime services. However, even with this option, the
1673 resultant kernel should continue to boot on existing non-EFI
1677 bool "EFI stub support"
1678 depends on EFI && !X86_USE_3DNOW
1681 This kernel feature allows a bzImage to be loaded directly
1682 by EFI firmware without the use of a bootloader.
1684 See Documentation/efi-stub.txt for more information.
1687 bool "EFI mixed-mode support"
1688 depends on EFI_STUB && X86_64
1690 Enabling this feature allows a 64-bit kernel to be booted
1691 on a 32-bit firmware, provided that your CPU supports 64-bit
1694 Note that it is not possible to boot a mixed-mode enabled
1695 kernel via the EFI boot stub - a bootloader that supports
1696 the EFI handover protocol must be used.
1702 prompt "Enable seccomp to safely compute untrusted bytecode"
1704 This kernel feature is useful for number crunching applications
1705 that may need to compute untrusted bytecode during their
1706 execution. By using pipes or other transports made available to
1707 the process as file descriptors supporting the read/write
1708 syscalls, it's possible to isolate those applications in
1709 their own address space using seccomp. Once seccomp is
1710 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1711 and the task is only allowed to execute a few safe syscalls
1712 defined by each seccomp mode.
1714 If unsure, say Y. Only embedded should say N here.
1716 source kernel/Kconfig.hz
1719 bool "kexec system call"
1721 kexec is a system call that implements the ability to shutdown your
1722 current kernel, and to start another kernel. It is like a reboot
1723 but it is independent of the system firmware. And like a reboot
1724 you can start any kernel with it, not just Linux.
1726 The name comes from the similarity to the exec system call.
1728 It is an ongoing process to be certain the hardware in a machine
1729 is properly shutdown, so do not be surprised if this code does not
1730 initially work for you. As of this writing the exact hardware
1731 interface is strongly in flux, so no good recommendation can be
1735 bool "kexec file based system call"
1740 depends on CRYPTO_SHA256=y
1742 This is new version of kexec system call. This system call is
1743 file based and takes file descriptors as system call argument
1744 for kernel and initramfs as opposed to list of segments as
1745 accepted by previous system call.
1747 config KEXEC_VERIFY_SIG
1748 bool "Verify kernel signature during kexec_file_load() syscall"
1749 depends on KEXEC_FILE
1751 This option makes kernel signature verification mandatory for
1752 the kexec_file_load() syscall.
1754 In addition to that option, you need to enable signature
1755 verification for the corresponding kernel image type being
1756 loaded in order for this to work.
1758 config KEXEC_BZIMAGE_VERIFY_SIG
1759 bool "Enable bzImage signature verification support"
1760 depends on KEXEC_VERIFY_SIG
1761 depends on SIGNED_PE_FILE_VERIFICATION
1762 select SYSTEM_TRUSTED_KEYRING
1764 Enable bzImage signature verification support.
1767 bool "kernel crash dumps"
1768 depends on X86_64 || (X86_32 && HIGHMEM)
1770 Generate crash dump after being started by kexec.
1771 This should be normally only set in special crash dump kernels
1772 which are loaded in the main kernel with kexec-tools into
1773 a specially reserved region and then later executed after
1774 a crash by kdump/kexec. The crash dump kernel must be compiled
1775 to a memory address not used by the main kernel or BIOS using
1776 PHYSICAL_START, or it must be built as a relocatable image
1777 (CONFIG_RELOCATABLE=y).
1778 For more details see Documentation/kdump/kdump.txt
1782 depends on KEXEC && HIBERNATION
1784 Jump between original kernel and kexeced kernel and invoke
1785 code in physical address mode via KEXEC
1787 config PHYSICAL_START
1788 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1791 This gives the physical address where the kernel is loaded.
1793 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1794 bzImage will decompress itself to above physical address and
1795 run from there. Otherwise, bzImage will run from the address where
1796 it has been loaded by the boot loader and will ignore above physical
1799 In normal kdump cases one does not have to set/change this option
1800 as now bzImage can be compiled as a completely relocatable image
1801 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1802 address. This option is mainly useful for the folks who don't want
1803 to use a bzImage for capturing the crash dump and want to use a
1804 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1805 to be specifically compiled to run from a specific memory area
1806 (normally a reserved region) and this option comes handy.
1808 So if you are using bzImage for capturing the crash dump,
1809 leave the value here unchanged to 0x1000000 and set
1810 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1811 for capturing the crash dump change this value to start of
1812 the reserved region. In other words, it can be set based on
1813 the "X" value as specified in the "crashkernel=YM@XM"
1814 command line boot parameter passed to the panic-ed
1815 kernel. Please take a look at Documentation/kdump/kdump.txt
1816 for more details about crash dumps.
1818 Usage of bzImage for capturing the crash dump is recommended as
1819 one does not have to build two kernels. Same kernel can be used
1820 as production kernel and capture kernel. Above option should have
1821 gone away after relocatable bzImage support is introduced. But it
1822 is present because there are users out there who continue to use
1823 vmlinux for dump capture. This option should go away down the
1826 Don't change this unless you know what you are doing.
1829 bool "Build a relocatable kernel"
1832 This builds a kernel image that retains relocation information
1833 so it can be loaded someplace besides the default 1MB.
1834 The relocations tend to make the kernel binary about 10% larger,
1835 but are discarded at runtime.
1837 One use is for the kexec on panic case where the recovery kernel
1838 must live at a different physical address than the primary
1841 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1842 it has been loaded at and the compile time physical address
1843 (CONFIG_PHYSICAL_START) is used as the minimum location.
1845 config RANDOMIZE_BASE
1846 bool "Randomize the address of the kernel image"
1847 depends on RELOCATABLE
1850 Randomizes the physical and virtual address at which the
1851 kernel image is decompressed, as a security feature that
1852 deters exploit attempts relying on knowledge of the location
1853 of kernel internals.
1855 Entropy is generated using the RDRAND instruction if it is
1856 supported. If RDTSC is supported, it is used as well. If
1857 neither RDRAND nor RDTSC are supported, then randomness is
1858 read from the i8254 timer.
1860 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1861 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1862 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1863 minimum of 2MiB, only 10 bits of entropy is theoretically
1864 possible. At best, due to page table layouts, 64-bit can use
1865 9 bits of entropy and 32-bit uses 8 bits.
1869 config RANDOMIZE_BASE_MAX_OFFSET
1870 hex "Maximum kASLR offset allowed" if EXPERT
1871 depends on RANDOMIZE_BASE
1872 range 0x0 0x20000000 if X86_32
1873 default "0x20000000" if X86_32
1874 range 0x0 0x40000000 if X86_64
1875 default "0x40000000" if X86_64
1877 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1878 memory is used to determine the maximal offset in bytes that will
1879 be applied to the kernel when kernel Address Space Layout
1880 Randomization (kASLR) is active. This must be a multiple of
1883 On 32-bit this is limited to 512MiB by page table layouts. The
1886 On 64-bit this is limited by how the kernel fixmap page table is
1887 positioned, so this cannot be larger than 1GiB currently. Without
1888 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1889 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1890 modules area will shrink to compensate, up to the current maximum
1891 1GiB to 1GiB split. The default is 1GiB.
1893 If unsure, leave at the default value.
1895 # Relocation on x86 needs some additional build support
1896 config X86_NEED_RELOCS
1898 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1900 config PHYSICAL_ALIGN
1901 hex "Alignment value to which kernel should be aligned"
1903 range 0x2000 0x1000000 if X86_32
1904 range 0x200000 0x1000000 if X86_64
1906 This value puts the alignment restrictions on physical address
1907 where kernel is loaded and run from. Kernel is compiled for an
1908 address which meets above alignment restriction.
1910 If bootloader loads the kernel at a non-aligned address and
1911 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1912 address aligned to above value and run from there.
1914 If bootloader loads the kernel at a non-aligned address and
1915 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1916 load address and decompress itself to the address it has been
1917 compiled for and run from there. The address for which kernel is
1918 compiled already meets above alignment restrictions. Hence the
1919 end result is that kernel runs from a physical address meeting
1920 above alignment restrictions.
1922 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1923 this value must be a multiple of 0x200000.
1925 Don't change this unless you know what you are doing.
1928 bool "Support for hot-pluggable CPUs"
1931 Say Y here to allow turning CPUs off and on. CPUs can be
1932 controlled through /sys/devices/system/cpu.
1933 ( Note: power management support will enable this option
1934 automatically on SMP systems. )
1935 Say N if you want to disable CPU hotplug.
1937 config BOOTPARAM_HOTPLUG_CPU0
1938 bool "Set default setting of cpu0_hotpluggable"
1940 depends on HOTPLUG_CPU
1942 Set whether default state of cpu0_hotpluggable is on or off.
1944 Say Y here to enable CPU0 hotplug by default. If this switch
1945 is turned on, there is no need to give cpu0_hotplug kernel
1946 parameter and the CPU0 hotplug feature is enabled by default.
1948 Please note: there are two known CPU0 dependencies if you want
1949 to enable the CPU0 hotplug feature either by this switch or by
1950 cpu0_hotplug kernel parameter.
1952 First, resume from hibernate or suspend always starts from CPU0.
1953 So hibernate and suspend are prevented if CPU0 is offline.
1955 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1956 offline if any interrupt can not migrate out of CPU0. There may
1957 be other CPU0 dependencies.
1959 Please make sure the dependencies are under your control before
1960 you enable this feature.
1962 Say N if you don't want to enable CPU0 hotplug feature by default.
1963 You still can enable the CPU0 hotplug feature at boot by kernel
1964 parameter cpu0_hotplug.
1966 config DEBUG_HOTPLUG_CPU0
1968 prompt "Debug CPU0 hotplug"
1969 depends on HOTPLUG_CPU
1971 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1972 soon as possible and boots up userspace with CPU0 offlined. User
1973 can online CPU0 back after boot time.
1975 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1976 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1977 compilation or giving cpu0_hotplug kernel parameter at boot.
1983 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1984 depends on X86_32 || IA32_EMULATION
1986 Certain buggy versions of glibc will crash if they are
1987 presented with a 32-bit vDSO that is not mapped at the address
1988 indicated in its segment table.
1990 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1991 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1992 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1993 the only released version with the bug, but OpenSUSE 9
1994 contains a buggy "glibc 2.3.2".
1996 The symptom of the bug is that everything crashes on startup, saying:
1997 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1999 Saying Y here changes the default value of the vdso32 boot
2000 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2001 This works around the glibc bug but hurts performance.
2003 If unsure, say N: if you are compiling your own kernel, you
2004 are unlikely to be using a buggy version of glibc.
2007 bool "Built-in kernel command line"
2009 Allow for specifying boot arguments to the kernel at
2010 build time. On some systems (e.g. embedded ones), it is
2011 necessary or convenient to provide some or all of the
2012 kernel boot arguments with the kernel itself (that is,
2013 to not rely on the boot loader to provide them.)
2015 To compile command line arguments into the kernel,
2016 set this option to 'Y', then fill in the
2017 the boot arguments in CONFIG_CMDLINE.
2019 Systems with fully functional boot loaders (i.e. non-embedded)
2020 should leave this option set to 'N'.
2023 string "Built-in kernel command string"
2024 depends on CMDLINE_BOOL
2027 Enter arguments here that should be compiled into the kernel
2028 image and used at boot time. If the boot loader provides a
2029 command line at boot time, it is appended to this string to
2030 form the full kernel command line, when the system boots.
2032 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2033 change this behavior.
2035 In most cases, the command line (whether built-in or provided
2036 by the boot loader) should specify the device for the root
2039 config CMDLINE_OVERRIDE
2040 bool "Built-in command line overrides boot loader arguments"
2041 depends on CMDLINE_BOOL
2043 Set this option to 'Y' to have the kernel ignore the boot loader
2044 command line, and use ONLY the built-in command line.
2046 This is used to work around broken boot loaders. This should
2047 be set to 'N' under normal conditions.
2049 source "kernel/livepatch/Kconfig"
2053 config ARCH_ENABLE_MEMORY_HOTPLUG
2055 depends on X86_64 || (X86_32 && HIGHMEM)
2057 config ARCH_ENABLE_MEMORY_HOTREMOVE
2059 depends on MEMORY_HOTPLUG
2061 config USE_PERCPU_NUMA_NODE_ID
2065 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2067 depends on X86_64 || X86_PAE
2069 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2071 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2073 menu "Power management and ACPI options"
2075 config ARCH_HIBERNATION_HEADER
2077 depends on X86_64 && HIBERNATION
2079 source "kernel/power/Kconfig"
2081 source "drivers/acpi/Kconfig"
2083 source "drivers/sfi/Kconfig"
2090 tristate "APM (Advanced Power Management) BIOS support"
2091 depends on X86_32 && PM_SLEEP
2093 APM is a BIOS specification for saving power using several different
2094 techniques. This is mostly useful for battery powered laptops with
2095 APM compliant BIOSes. If you say Y here, the system time will be
2096 reset after a RESUME operation, the /proc/apm device will provide
2097 battery status information, and user-space programs will receive
2098 notification of APM "events" (e.g. battery status change).
2100 If you select "Y" here, you can disable actual use of the APM
2101 BIOS by passing the "apm=off" option to the kernel at boot time.
2103 Note that the APM support is almost completely disabled for
2104 machines with more than one CPU.
2106 In order to use APM, you will need supporting software. For location
2107 and more information, read <file:Documentation/power/apm-acpi.txt>
2108 and the Battery Powered Linux mini-HOWTO, available from
2109 <http://www.tldp.org/docs.html#howto>.
2111 This driver does not spin down disk drives (see the hdparm(8)
2112 manpage ("man 8 hdparm") for that), and it doesn't turn off
2113 VESA-compliant "green" monitors.
2115 This driver does not support the TI 4000M TravelMate and the ACER
2116 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2117 desktop machines also don't have compliant BIOSes, and this driver
2118 may cause those machines to panic during the boot phase.
2120 Generally, if you don't have a battery in your machine, there isn't
2121 much point in using this driver and you should say N. If you get
2122 random kernel OOPSes or reboots that don't seem to be related to
2123 anything, try disabling/enabling this option (or disabling/enabling
2126 Some other things you should try when experiencing seemingly random,
2129 1) make sure that you have enough swap space and that it is
2131 2) pass the "no-hlt" option to the kernel
2132 3) switch on floating point emulation in the kernel and pass
2133 the "no387" option to the kernel
2134 4) pass the "floppy=nodma" option to the kernel
2135 5) pass the "mem=4M" option to the kernel (thereby disabling
2136 all but the first 4 MB of RAM)
2137 6) make sure that the CPU is not over clocked.
2138 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2139 8) disable the cache from your BIOS settings
2140 9) install a fan for the video card or exchange video RAM
2141 10) install a better fan for the CPU
2142 11) exchange RAM chips
2143 12) exchange the motherboard.
2145 To compile this driver as a module, choose M here: the
2146 module will be called apm.
2150 config APM_IGNORE_USER_SUSPEND
2151 bool "Ignore USER SUSPEND"
2153 This option will ignore USER SUSPEND requests. On machines with a
2154 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2155 series notebooks, it is necessary to say Y because of a BIOS bug.
2157 config APM_DO_ENABLE
2158 bool "Enable PM at boot time"
2160 Enable APM features at boot time. From page 36 of the APM BIOS
2161 specification: "When disabled, the APM BIOS does not automatically
2162 power manage devices, enter the Standby State, enter the Suspend
2163 State, or take power saving steps in response to CPU Idle calls."
2164 This driver will make CPU Idle calls when Linux is idle (unless this
2165 feature is turned off -- see "Do CPU IDLE calls", below). This
2166 should always save battery power, but more complicated APM features
2167 will be dependent on your BIOS implementation. You may need to turn
2168 this option off if your computer hangs at boot time when using APM
2169 support, or if it beeps continuously instead of suspending. Turn
2170 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2171 T400CDT. This is off by default since most machines do fine without
2176 bool "Make CPU Idle calls when idle"
2178 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2179 On some machines, this can activate improved power savings, such as
2180 a slowed CPU clock rate, when the machine is idle. These idle calls
2181 are made after the idle loop has run for some length of time (e.g.,
2182 333 mS). On some machines, this will cause a hang at boot time or
2183 whenever the CPU becomes idle. (On machines with more than one CPU,
2184 this option does nothing.)
2186 config APM_DISPLAY_BLANK
2187 bool "Enable console blanking using APM"
2189 Enable console blanking using the APM. Some laptops can use this to
2190 turn off the LCD backlight when the screen blanker of the Linux
2191 virtual console blanks the screen. Note that this is only used by
2192 the virtual console screen blanker, and won't turn off the backlight
2193 when using the X Window system. This also doesn't have anything to
2194 do with your VESA-compliant power-saving monitor. Further, this
2195 option doesn't work for all laptops -- it might not turn off your
2196 backlight at all, or it might print a lot of errors to the console,
2197 especially if you are using gpm.
2199 config APM_ALLOW_INTS
2200 bool "Allow interrupts during APM BIOS calls"
2202 Normally we disable external interrupts while we are making calls to
2203 the APM BIOS as a measure to lessen the effects of a badly behaving
2204 BIOS implementation. The BIOS should reenable interrupts if it
2205 needs to. Unfortunately, some BIOSes do not -- especially those in
2206 many of the newer IBM Thinkpads. If you experience hangs when you
2207 suspend, try setting this to Y. Otherwise, say N.
2211 source "drivers/cpufreq/Kconfig"
2213 source "drivers/cpuidle/Kconfig"
2215 source "drivers/idle/Kconfig"
2220 menu "Bus options (PCI etc.)"
2226 Find out whether you have a PCI motherboard. PCI is the name of a
2227 bus system, i.e. the way the CPU talks to the other stuff inside
2228 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2229 VESA. If you have PCI, say Y, otherwise N.
2232 prompt "PCI access mode"
2233 depends on X86_32 && PCI
2236 On PCI systems, the BIOS can be used to detect the PCI devices and
2237 determine their configuration. However, some old PCI motherboards
2238 have BIOS bugs and may crash if this is done. Also, some embedded
2239 PCI-based systems don't have any BIOS at all. Linux can also try to
2240 detect the PCI hardware directly without using the BIOS.
2242 With this option, you can specify how Linux should detect the
2243 PCI devices. If you choose "BIOS", the BIOS will be used,
2244 if you choose "Direct", the BIOS won't be used, and if you
2245 choose "MMConfig", then PCI Express MMCONFIG will be used.
2246 If you choose "Any", the kernel will try MMCONFIG, then the
2247 direct access method and falls back to the BIOS if that doesn't
2248 work. If unsure, go with the default, which is "Any".
2253 config PCI_GOMMCONFIG
2270 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2272 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2275 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2279 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2283 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2287 depends on PCI && XEN
2295 bool "Support mmconfig PCI config space access"
2296 depends on X86_64 && PCI && ACPI
2298 config PCI_CNB20LE_QUIRK
2299 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2302 Read the PCI windows out of the CNB20LE host bridge. This allows
2303 PCI hotplug to work on systems with the CNB20LE chipset which do
2306 There's no public spec for this chipset, and this functionality
2307 is known to be incomplete.
2309 You should say N unless you know you need this.
2311 source "drivers/pci/pcie/Kconfig"
2313 source "drivers/pci/Kconfig"
2315 # x86_64 have no ISA slots, but can have ISA-style DMA.
2317 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2320 Enables ISA-style DMA support for devices requiring such controllers.
2328 Find out whether you have ISA slots on your motherboard. ISA is the
2329 name of a bus system, i.e. the way the CPU talks to the other stuff
2330 inside your box. Other bus systems are PCI, EISA, MicroChannel
2331 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2332 newer boards don't support it. If you have ISA, say Y, otherwise N.
2338 The Extended Industry Standard Architecture (EISA) bus was
2339 developed as an open alternative to the IBM MicroChannel bus.
2341 The EISA bus provided some of the features of the IBM MicroChannel
2342 bus while maintaining backward compatibility with cards made for
2343 the older ISA bus. The EISA bus saw limited use between 1988 and
2344 1995 when it was made obsolete by the PCI bus.
2346 Say Y here if you are building a kernel for an EISA-based machine.
2350 source "drivers/eisa/Kconfig"
2353 tristate "NatSemi SCx200 support"
2355 This provides basic support for National Semiconductor's
2356 (now AMD's) Geode processors. The driver probes for the
2357 PCI-IDs of several on-chip devices, so its a good dependency
2358 for other scx200_* drivers.
2360 If compiled as a module, the driver is named scx200.
2362 config SCx200HR_TIMER
2363 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2367 This driver provides a clocksource built upon the on-chip
2368 27MHz high-resolution timer. Its also a workaround for
2369 NSC Geode SC-1100's buggy TSC, which loses time when the
2370 processor goes idle (as is done by the scheduler). The
2371 other workaround is idle=poll boot option.
2374 bool "One Laptop Per Child support"
2381 Add support for detecting the unique features of the OLPC
2385 bool "OLPC XO-1 Power Management"
2386 depends on OLPC && MFD_CS5535 && PM_SLEEP
2389 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2392 bool "OLPC XO-1 Real Time Clock"
2393 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2395 Add support for the XO-1 real time clock, which can be used as a
2396 programmable wakeup source.
2399 bool "OLPC XO-1 SCI extras"
2400 depends on OLPC && OLPC_XO1_PM
2406 Add support for SCI-based features of the OLPC XO-1 laptop:
2407 - EC-driven system wakeups
2411 - AC adapter status updates
2412 - Battery status updates
2414 config OLPC_XO15_SCI
2415 bool "OLPC XO-1.5 SCI extras"
2416 depends on OLPC && ACPI
2419 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2420 - EC-driven system wakeups
2421 - AC adapter status updates
2422 - Battery status updates
2425 bool "PCEngines ALIX System Support (LED setup)"
2428 This option enables system support for the PCEngines ALIX.
2429 At present this just sets up LEDs for GPIO control on
2430 ALIX2/3/6 boards. However, other system specific setup should
2433 Note: You must still enable the drivers for GPIO and LED support
2434 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2436 Note: You have to set alix.force=1 for boards with Award BIOS.
2439 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2442 This option enables system support for the Soekris Engineering net5501.
2445 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2449 This option enables system support for the Traverse Technologies GEOS.
2452 bool "Technologic Systems TS-5500 platform support"
2454 select CHECK_SIGNATURE
2458 This option enables system support for the Technologic Systems TS-5500.
2464 depends on CPU_SUP_AMD && PCI
2466 source "drivers/pcmcia/Kconfig"
2468 source "drivers/pci/hotplug/Kconfig"
2471 tristate "RapidIO support"
2475 If enabled this option will include drivers and the core
2476 infrastructure code to support RapidIO interconnect devices.
2478 source "drivers/rapidio/Kconfig"
2481 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2483 Firmwares often provide initial graphics framebuffers so the BIOS,
2484 bootloader or kernel can show basic video-output during boot for
2485 user-guidance and debugging. Historically, x86 used the VESA BIOS
2486 Extensions and EFI-framebuffers for this, which are mostly limited
2488 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2489 framebuffers so the new generic system-framebuffer drivers can be
2490 used on x86. If the framebuffer is not compatible with the generic
2491 modes, it is adverticed as fallback platform framebuffer so legacy
2492 drivers like efifb, vesafb and uvesafb can pick it up.
2493 If this option is not selected, all system framebuffers are always
2494 marked as fallback platform framebuffers as usual.
2496 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2497 not be able to pick up generic system framebuffers if this option
2498 is selected. You are highly encouraged to enable simplefb as
2499 replacement if you select this option. simplefb can correctly deal
2500 with generic system framebuffers. But you should still keep vesafb
2501 and others enabled as fallback if a system framebuffer is
2502 incompatible with simplefb.
2509 menu "Executable file formats / Emulations"
2511 source "fs/Kconfig.binfmt"
2513 config IA32_EMULATION
2514 bool "IA32 Emulation"
2517 select COMPAT_BINFMT_ELF
2520 Include code to run legacy 32-bit programs under a
2521 64-bit kernel. You should likely turn this on, unless you're
2522 100% sure that you don't have any 32-bit programs left.
2525 tristate "IA32 a.out support"
2526 depends on IA32_EMULATION
2528 Support old a.out binaries in the 32bit emulation.
2531 bool "x32 ABI for 64-bit mode"
2532 depends on X86_64 && IA32_EMULATION
2534 Include code to run binaries for the x32 native 32-bit ABI
2535 for 64-bit processors. An x32 process gets access to the
2536 full 64-bit register file and wide data path while leaving
2537 pointers at 32 bits for smaller memory footprint.
2539 You will need a recent binutils (2.22 or later) with
2540 elf32_x86_64 support enabled to compile a kernel with this
2545 depends on IA32_EMULATION || X86_X32
2546 select ARCH_WANT_OLD_COMPAT_IPC
2549 config COMPAT_FOR_U64_ALIGNMENT
2552 config SYSVIPC_COMPAT
2564 config HAVE_ATOMIC_IOMAP
2568 config X86_DEV_DMA_OPS
2570 depends on X86_64 || STA2X11
2572 config X86_DMA_REMAP
2580 source "net/Kconfig"
2582 source "drivers/Kconfig"
2584 source "drivers/firmware/Kconfig"
2588 source "arch/x86/Kconfig.debug"
2590 source "security/Kconfig"
2592 source "crypto/Kconfig"
2594 source "arch/x86/kvm/Kconfig"
2596 source "lib/Kconfig"