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
18 select X86_DEV_DMA_OPS
19 select ARCH_USE_CMPXCHG_LOCKREF
25 select HAVE_PREEMPT_LAZY
26 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
27 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
28 select ARCH_HAS_FAST_MULTIPLIER
29 select ARCH_HAS_GCOV_PROFILE_ALL
30 select ARCH_MIGHT_HAVE_PC_PARPORT
31 select ARCH_MIGHT_HAVE_PC_SERIO
32 select HAVE_AOUT if X86_32
33 select HAVE_UNSTABLE_SCHED_CLOCK
34 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
35 select ARCH_SUPPORTS_INT128 if X86_64
38 select HAVE_PCSPKR_PLATFORM
39 select HAVE_PERF_EVENTS
40 select HAVE_IOREMAP_PROT
43 select HAVE_MEMBLOCK_NODE_MAP
44 select ARCH_DISCARD_MEMBLOCK
45 select ARCH_WANT_OPTIONAL_GPIOLIB
46 select ARCH_WANT_FRAME_POINTERS
48 select HAVE_DMA_CONTIGUOUS
49 select HAVE_KRETPROBES
50 select GENERIC_EARLY_IOREMAP
52 select HAVE_KPROBES_ON_FTRACE
53 select HAVE_FTRACE_MCOUNT_RECORD
54 select HAVE_FENTRY if X86_64
55 select HAVE_C_RECORDMCOUNT
56 select HAVE_DYNAMIC_FTRACE
57 select HAVE_DYNAMIC_FTRACE_WITH_REGS
58 select HAVE_FUNCTION_TRACER
59 select HAVE_FUNCTION_GRAPH_TRACER
60 select HAVE_FUNCTION_GRAPH_FP_TEST
61 select HAVE_SYSCALL_TRACEPOINTS
62 select SYSCTL_EXCEPTION_TRACE
65 select HAVE_ARCH_TRACEHOOK
66 select HAVE_GENERIC_DMA_COHERENT if X86_32
67 select HAVE_EFFICIENT_UNALIGNED_ACCESS
68 select USER_STACKTRACE_SUPPORT
69 select HAVE_REGS_AND_STACK_ACCESS_API
70 select HAVE_DMA_API_DEBUG
71 select HAVE_KERNEL_GZIP
72 select HAVE_KERNEL_BZIP2
73 select HAVE_KERNEL_LZMA
75 select HAVE_KERNEL_LZO
76 select HAVE_KERNEL_LZ4
77 select HAVE_HW_BREAKPOINT
78 select HAVE_MIXED_BREAKPOINTS_REGS
80 select HAVE_PERF_EVENTS_NMI
82 select HAVE_PERF_USER_STACK_DUMP
83 select HAVE_DEBUG_KMEMLEAK
85 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
86 select HAVE_CMPXCHG_LOCAL
87 select HAVE_CMPXCHG_DOUBLE
88 select HAVE_ARCH_KMEMCHECK
89 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
90 select HAVE_USER_RETURN_NOTIFIER
91 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
92 select HAVE_ARCH_JUMP_LABEL
93 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
95 select GENERIC_FIND_FIRST_BIT
96 select GENERIC_IRQ_PROBE
97 select GENERIC_PENDING_IRQ if SMP
98 select GENERIC_IRQ_SHOW
99 select GENERIC_CLOCKEVENTS_MIN_ADJUST
100 select IRQ_FORCED_THREADING
101 select HAVE_BPF_JIT if X86_64
102 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
103 select ARCH_HAS_SG_CHAIN
105 select ARCH_HAVE_NMI_SAFE_CMPXCHG
107 select DCACHE_WORD_ACCESS
108 select GENERIC_SMP_IDLE_THREAD
109 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
110 select HAVE_ARCH_SECCOMP_FILTER
111 select BUILDTIME_EXTABLE_SORT
112 select GENERIC_CMOS_UPDATE
113 select HAVE_ARCH_SOFT_DIRTY if X86_64
114 select CLOCKSOURCE_WATCHDOG
115 select GENERIC_CLOCKEVENTS
116 select ARCH_CLOCKSOURCE_DATA
117 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
118 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
119 select GENERIC_TIME_VSYSCALL
120 select GENERIC_STRNCPY_FROM_USER
121 select GENERIC_STRNLEN_USER
122 select HAVE_CONTEXT_TRACKING if X86_64
123 select HAVE_IRQ_TIME_ACCOUNTING
125 select MODULES_USE_ELF_REL if X86_32
126 select MODULES_USE_ELF_RELA if X86_64
127 select CLONE_BACKWARDS if X86_32
128 select ARCH_USE_BUILTIN_BSWAP
129 select ARCH_USE_QUEUE_RWLOCK
130 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
131 select OLD_SIGACTION if X86_32
132 select COMPAT_OLD_SIGACTION if IA32_EMULATION
134 select HAVE_DEBUG_STACKOVERFLOW
135 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
136 select HAVE_CC_STACKPROTECTOR
137 select GENERIC_CPU_AUTOPROBE
138 select HAVE_ARCH_AUDITSYSCALL
139 select ARCH_SUPPORTS_ATOMIC_RMW
140 select HAVE_ACPI_APEI if ACPI
141 select HAVE_ACPI_APEI_NMI if ACPI
142 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
143 select X86_FEATURE_NAMES if PROC_FS
146 config INSTRUCTION_DECODER
148 depends on KPROBES || PERF_EVENTS || UPROBES
150 config PERF_EVENTS_INTEL_UNCORE
152 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
156 default "elf32-i386" if X86_32
157 default "elf64-x86-64" if X86_64
159 config ARCH_DEFCONFIG
161 default "arch/x86/configs/i386_defconfig" if X86_32
162 default "arch/x86/configs/x86_64_defconfig" if X86_64
164 config LOCKDEP_SUPPORT
167 config STACKTRACE_SUPPORT
170 config HAVE_LATENCYTOP_SUPPORT
179 config NEED_DMA_MAP_STATE
181 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
183 config NEED_SG_DMA_LENGTH
186 config GENERIC_ISA_DMA
188 depends on ISA_DMA_API
193 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
195 config GENERIC_BUG_RELATIVE_POINTERS
198 config GENERIC_HWEIGHT
201 config ARCH_MAY_HAVE_PC_FDC
203 depends on ISA_DMA_API
205 config RWSEM_GENERIC_SPINLOCK
206 def_bool PREEMPT_RT_FULL
208 config RWSEM_XCHGADD_ALGORITHM
209 def_bool !RWSEM_GENERIC_SPINLOCK && !PREEMPT_RT_FULL
211 config GENERIC_CALIBRATE_DELAY
214 config ARCH_HAS_CPU_RELAX
217 config ARCH_HAS_CACHE_LINE_SIZE
220 config HAVE_SETUP_PER_CPU_AREA
223 config NEED_PER_CPU_EMBED_FIRST_CHUNK
226 config NEED_PER_CPU_PAGE_FIRST_CHUNK
229 config ARCH_HIBERNATION_POSSIBLE
232 config ARCH_SUSPEND_POSSIBLE
235 config ARCH_WANT_HUGE_PMD_SHARE
238 config ARCH_WANT_GENERAL_HUGETLB
249 config ARCH_SUPPORTS_OPTIMIZED_INLINING
252 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
255 config HAVE_INTEL_TXT
257 depends on INTEL_IOMMU && ACPI
261 depends on X86_32 && SMP
265 depends on X86_64 && SMP
271 config X86_32_LAZY_GS
273 depends on X86_32 && !CC_STACKPROTECTOR
275 config ARCH_HWEIGHT_CFLAGS
277 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
278 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
280 config ARCH_SUPPORTS_UPROBES
283 config FIX_EARLYCON_MEM
286 source "init/Kconfig"
287 source "kernel/Kconfig.freezer"
289 menu "Processor type and features"
292 bool "DMA memory allocation support" if EXPERT
295 DMA memory allocation support allows devices with less than 32-bit
296 addressing to allocate within the first 16MB of address space.
297 Disable if no such devices will be used.
302 bool "Symmetric multi-processing support"
304 This enables support for systems with more than one CPU. If you have
305 a system with only one CPU, say N. If you have a system with more
308 If you say N here, the kernel will run on uni- and multiprocessor
309 machines, but will use only one CPU of a multiprocessor machine. If
310 you say Y here, the kernel will run on many, but not all,
311 uniprocessor machines. On a uniprocessor machine, the kernel
312 will run faster if you say N here.
314 Note that if you say Y here and choose architecture "586" or
315 "Pentium" under "Processor family", the kernel will not work on 486
316 architectures. Similarly, multiprocessor kernels for the "PPro"
317 architecture may not work on all Pentium based boards.
319 People using multiprocessor machines who say Y here should also say
320 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
321 Management" code will be disabled if you say Y here.
323 See also <file:Documentation/x86/i386/IO-APIC.txt>,
324 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
325 <http://www.tldp.org/docs.html#howto>.
327 If you don't know what to do here, say N.
329 config X86_FEATURE_NAMES
330 bool "Processor feature human-readable names" if EMBEDDED
333 This option compiles in a table of x86 feature bits and corresponding
334 names. This is required to support /proc/cpuinfo and a few kernel
335 messages. You can disable this to save space, at the expense of
336 making those few kernel messages show numeric feature bits instead.
341 bool "Support x2apic"
342 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
344 This enables x2apic support on CPUs that have this feature.
346 This allows 32-bit apic IDs (so it can support very large systems),
347 and accesses the local apic via MSRs not via mmio.
349 If you don't know what to do here, say N.
352 bool "Enable MPS table" if ACPI || SFI
354 depends on X86_LOCAL_APIC
356 For old smp systems that do not have proper acpi support. Newer systems
357 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
360 bool "Support for big SMP systems with more than 8 CPUs"
361 depends on X86_32 && SMP
363 This option is needed for the systems that have more than 8 CPUs
367 depends on X86_GOLDFISH
370 config X86_EXTENDED_PLATFORM
371 bool "Support for extended (non-PC) x86 platforms"
374 If you disable this option then the kernel will only support
375 standard PC platforms. (which covers the vast majority of
378 If you enable this option then you'll be able to select support
379 for the following (non-PC) 32 bit x86 platforms:
380 Goldfish (Android emulator)
383 SGI 320/540 (Visual Workstation)
384 STA2X11-based (e.g. Northville)
385 Moorestown MID devices
387 If you have one of these systems, or if you want to build a
388 generic distribution kernel, say Y here - otherwise say N.
392 config X86_EXTENDED_PLATFORM
393 bool "Support for extended (non-PC) x86 platforms"
396 If you disable this option then the kernel will only support
397 standard PC platforms. (which covers the vast majority of
400 If you enable this option then you'll be able to select support
401 for the following (non-PC) 64 bit x86 platforms:
406 If you have one of these systems, or if you want to build a
407 generic distribution kernel, say Y here - otherwise say N.
409 # This is an alphabetically sorted list of 64 bit extended platforms
410 # Please maintain the alphabetic order if and when there are additions
412 bool "Numascale NumaChip"
414 depends on X86_EXTENDED_PLATFORM
417 depends on X86_X2APIC
418 depends on PCI_MMCONFIG
420 Adds support for Numascale NumaChip large-SMP systems. Needed to
421 enable more than ~168 cores.
422 If you don't have one of these, you should say N here.
426 select HYPERVISOR_GUEST
428 depends on X86_64 && PCI
429 depends on X86_EXTENDED_PLATFORM
432 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
433 supposed to run on these EM64T-based machines. Only choose this option
434 if you have one of these machines.
437 bool "SGI Ultraviolet"
439 depends on X86_EXTENDED_PLATFORM
441 depends on X86_X2APIC
443 This option is needed in order to support SGI Ultraviolet systems.
444 If you don't have one of these, you should say N here.
446 # Following is an alphabetically sorted list of 32 bit extended platforms
447 # Please maintain the alphabetic order if and when there are additions
450 bool "Goldfish (Virtual Platform)"
451 depends on X86_EXTENDED_PLATFORM
453 Enable support for the Goldfish virtual platform used primarily
454 for Android development. Unless you are building for the Android
455 Goldfish emulator say N here.
458 bool "CE4100 TV platform"
460 depends on PCI_GODIRECT
461 depends on X86_IO_APIC
463 depends on X86_EXTENDED_PLATFORM
464 select X86_REBOOTFIXUPS
466 select OF_EARLY_FLATTREE
469 Select for the Intel CE media processor (CE4100) SOC.
470 This option compiles in support for the CE4100 SOC for settop
471 boxes and media devices.
474 bool "Intel MID platform support"
476 depends on X86_EXTENDED_PLATFORM
477 depends on X86_PLATFORM_DEVICES
480 depends on X86_IO_APIC
486 select MFD_INTEL_MSIC
488 Select to build a kernel capable of supporting Intel MID (Mobile
489 Internet Device) platform systems which do not have the PCI legacy
490 interfaces. If you are building for a PC class system say N here.
492 Intel MID platforms are based on an Intel processor and chipset which
493 consume less power than most of the x86 derivatives.
495 config X86_INTEL_QUARK
496 bool "Intel Quark platform support"
498 depends on X86_EXTENDED_PLATFORM
499 depends on X86_PLATFORM_DEVICES
503 depends on X86_IO_APIC
508 Select to include support for Quark X1000 SoC.
509 Say Y here if you have a Quark based system such as the Arduino
510 compatible Intel Galileo.
512 config X86_INTEL_LPSS
513 bool "Intel Low Power Subsystem Support"
518 Select to build support for Intel Low Power Subsystem such as
519 found on Intel Lynxpoint PCH. Selecting this option enables
520 things like clock tree (common clock framework) and pincontrol
521 which are needed by the LPSS peripheral drivers.
523 config X86_AMD_PLATFORM_DEVICE
524 bool "AMD ACPI2Platform devices support"
529 Select to interpret AMD specific ACPI device to platform device
530 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
531 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
532 implemented under PINCTRL subsystem.
535 tristate "Intel SoC IOSF Sideband support for SoC platforms"
538 This option enables sideband register access support for Intel SoC
539 platforms. On these platforms the IOSF sideband is used in lieu of
540 MSR's for some register accesses, mostly but not limited to thermal
541 and power. Drivers may query the availability of this device to
542 determine if they need the sideband in order to work on these
543 platforms. The sideband is available on the following SoC products.
544 This list is not meant to be exclusive.
549 You should say Y if you are running a kernel on one of these SoC's.
551 config IOSF_MBI_DEBUG
552 bool "Enable IOSF sideband access through debugfs"
553 depends on IOSF_MBI && DEBUG_FS
555 Select this option to expose the IOSF sideband access registers (MCR,
556 MDR, MCRX) through debugfs to write and read register information from
557 different units on the SoC. This is most useful for obtaining device
558 state information for debug and analysis. As this is a general access
559 mechanism, users of this option would have specific knowledge of the
560 device they want to access.
562 If you don't require the option or are in doubt, say N.
565 bool "RDC R-321x SoC"
567 depends on X86_EXTENDED_PLATFORM
569 select X86_REBOOTFIXUPS
571 This option is needed for RDC R-321x system-on-chip, also known
573 If you don't have one of these chips, you should say N here.
575 config X86_32_NON_STANDARD
576 bool "Support non-standard 32-bit SMP architectures"
577 depends on X86_32 && SMP
578 depends on X86_EXTENDED_PLATFORM
580 This option compiles in the bigsmp and STA2X11 default
581 subarchitectures. It is intended for a generic binary
582 kernel. If you select them all, kernel will probe it one by
583 one and will fallback to default.
585 # Alphabetically sorted list of Non standard 32 bit platforms
587 config X86_SUPPORTS_MEMORY_FAILURE
589 # MCE code calls memory_failure():
591 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
592 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
593 depends on X86_64 || !SPARSEMEM
594 select ARCH_SUPPORTS_MEMORY_FAILURE
597 bool "STA2X11 Companion Chip Support"
598 depends on X86_32_NON_STANDARD && PCI
599 select X86_DEV_DMA_OPS
603 select ARCH_REQUIRE_GPIOLIB
606 This adds support for boards based on the STA2X11 IO-Hub,
607 a.k.a. "ConneXt". The chip is used in place of the standard
608 PC chipset, so all "standard" peripherals are missing. If this
609 option is selected the kernel will still be able to boot on
610 standard PC machines.
613 tristate "Eurobraille/Iris poweroff module"
616 The Iris machines from EuroBraille do not have APM or ACPI support
617 to shut themselves down properly. A special I/O sequence is
618 needed to do so, which is what this module does at
621 This is only for Iris machines from EuroBraille.
625 config SCHED_OMIT_FRAME_POINTER
627 prompt "Single-depth WCHAN output"
630 Calculate simpler /proc/<PID>/wchan values. If this option
631 is disabled then wchan values will recurse back to the
632 caller function. This provides more accurate wchan values,
633 at the expense of slightly more scheduling overhead.
635 If in doubt, say "Y".
637 menuconfig HYPERVISOR_GUEST
638 bool "Linux guest support"
640 Say Y here to enable options for running Linux under various hyper-
641 visors. This option enables basic hypervisor detection and platform
644 If you say N, all options in this submenu will be skipped and
645 disabled, and Linux guest support won't be built in.
650 bool "Enable paravirtualization code"
652 This changes the kernel so it can modify itself when it is run
653 under a hypervisor, potentially improving performance significantly
654 over full virtualization. However, when run without a hypervisor
655 the kernel is theoretically slower and slightly larger.
657 config PARAVIRT_DEBUG
658 bool "paravirt-ops debugging"
659 depends on PARAVIRT && DEBUG_KERNEL
661 Enable to debug paravirt_ops internals. Specifically, BUG if
662 a paravirt_op is missing when it is called.
664 config PARAVIRT_SPINLOCKS
665 bool "Paravirtualization layer for spinlocks"
666 depends on PARAVIRT && SMP
667 select UNINLINE_SPIN_UNLOCK
669 Paravirtualized spinlocks allow a pvops backend to replace the
670 spinlock implementation with something virtualization-friendly
671 (for example, block the virtual CPU rather than spinning).
673 It has a minimal impact on native kernels and gives a nice performance
674 benefit on paravirtualized KVM / Xen kernels.
676 If you are unsure how to answer this question, answer Y.
678 source "arch/x86/xen/Kconfig"
681 bool "KVM Guest support (including kvmclock)"
683 select PARAVIRT_CLOCK
686 This option enables various optimizations for running under the KVM
687 hypervisor. It includes a paravirtualized clock, so that instead
688 of relying on a PIT (or probably other) emulation by the
689 underlying device model, the host provides the guest with
690 timing infrastructure such as time of day, and system time
693 bool "Enable debug information for KVM Guests in debugfs"
694 depends on KVM_GUEST && DEBUG_FS
697 This option enables collection of various statistics for KVM guest.
698 Statistics are displayed in debugfs filesystem. Enabling this option
699 may incur significant overhead.
701 source "arch/x86/lguest/Kconfig"
703 config PARAVIRT_TIME_ACCOUNTING
704 bool "Paravirtual steal time accounting"
708 Select this option to enable fine granularity task steal time
709 accounting. Time spent executing other tasks in parallel with
710 the current vCPU is discounted from the vCPU power. To account for
711 that, there can be a small performance impact.
713 If in doubt, say N here.
715 config PARAVIRT_CLOCK
718 endif #HYPERVISOR_GUEST
726 This option adds a kernel parameter 'memtest', which allows memtest
728 memtest=0, mean disabled; -- default
729 memtest=1, mean do 1 test pattern;
731 memtest=4, mean do 4 test patterns.
732 If you are unsure how to answer this question, answer N.
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 if !PREEMPT_RT_FULL
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
865 This allows you to specify the maximum number of CPUs which this
866 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
867 supported value is 4096, otherwise the maximum value is 512. The
868 minimum value which makes sense is 2.
870 This is purely to save memory - each supported CPU adds
871 approximately eight kilobytes to the kernel image.
874 bool "SMT (Hyperthreading) scheduler support"
877 SMT scheduler support improves the CPU scheduler's decision making
878 when dealing with Intel Pentium 4 chips with HyperThreading at a
879 cost of slightly increased overhead in some places. If unsure say
884 prompt "Multi-core scheduler support"
887 Multi-core scheduler support improves the CPU scheduler's decision
888 making when dealing with multi-core CPU chips at a cost of slightly
889 increased overhead in some places. If unsure say N here.
891 source "kernel/Kconfig.preempt"
895 depends on !SMP && X86_LOCAL_APIC
898 bool "Local APIC support on uniprocessors"
899 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
901 A local APIC (Advanced Programmable Interrupt Controller) is an
902 integrated interrupt controller in the CPU. If you have a single-CPU
903 system which has a processor with a local APIC, you can say Y here to
904 enable and use it. If you say Y here even though your machine doesn't
905 have a local APIC, then the kernel will still run with no slowdown at
906 all. The local APIC supports CPU-generated self-interrupts (timer,
907 performance counters), and the NMI watchdog which detects hard
910 config X86_UP_APIC_MSI
912 select X86_UP_APIC if X86_32 && !SMP && !X86_32_NON_STANDARD && PCI_MSI
915 bool "IO-APIC support on uniprocessors"
916 depends on X86_UP_APIC
918 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
919 SMP-capable replacement for PC-style interrupt controllers. Most
920 SMP systems and many recent uniprocessor systems have one.
922 If you have a single-CPU system with an IO-APIC, you can say Y here
923 to use it. If you say Y here even though your machine doesn't have
924 an IO-APIC, then the kernel will still run with no slowdown at all.
926 config X86_LOCAL_APIC
928 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
929 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
932 def_bool X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
933 depends on X86_LOCAL_APIC
936 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
937 bool "Reroute for broken boot IRQs"
938 depends on X86_IO_APIC
940 This option enables a workaround that fixes a source of
941 spurious interrupts. This is recommended when threaded
942 interrupt handling is used on systems where the generation of
943 superfluous "boot interrupts" cannot be disabled.
945 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
946 entry in the chipset's IO-APIC is masked (as, e.g. the RT
947 kernel does during interrupt handling). On chipsets where this
948 boot IRQ generation cannot be disabled, this workaround keeps
949 the original IRQ line masked so that only the equivalent "boot
950 IRQ" is delivered to the CPUs. The workaround also tells the
951 kernel to set up the IRQ handler on the boot IRQ line. In this
952 way only one interrupt is delivered to the kernel. Otherwise
953 the spurious second interrupt may cause the kernel to bring
954 down (vital) interrupt lines.
956 Only affects "broken" chipsets. Interrupt sharing may be
957 increased on these systems.
960 bool "Machine Check / overheating reporting"
963 Machine Check support allows the processor to notify the
964 kernel if it detects a problem (e.g. overheating, data corruption).
965 The action the kernel takes depends on the severity of the problem,
966 ranging from warning messages to halting the machine.
970 prompt "Intel MCE features"
971 depends on X86_MCE && X86_LOCAL_APIC
973 Additional support for intel specific MCE features such as
978 prompt "AMD MCE features"
979 depends on X86_MCE && X86_LOCAL_APIC
981 Additional support for AMD specific MCE features such as
982 the DRAM Error Threshold.
984 config X86_ANCIENT_MCE
985 bool "Support for old Pentium 5 / WinChip machine checks"
986 depends on X86_32 && X86_MCE
988 Include support for machine check handling on old Pentium 5 or WinChip
989 systems. These typically need to be enabled explicitly on the command
992 config X86_MCE_THRESHOLD
993 depends on X86_MCE_AMD || X86_MCE_INTEL
996 config X86_MCE_INJECT
998 tristate "Machine check injector support"
1000 Provide support for injecting machine checks for testing purposes.
1001 If you don't know what a machine check is and you don't do kernel
1002 QA it is safe to say n.
1004 config X86_THERMAL_VECTOR
1006 depends on X86_MCE_INTEL
1009 bool "Enable VM86 support" if EXPERT
1013 This option is required by programs like DOSEMU to run
1014 16-bit real mode legacy code on x86 processors. It also may
1015 be needed by software like XFree86 to initialize some video
1016 cards via BIOS. Disabling this option saves about 6K.
1019 bool "Enable support for 16-bit segments" if EXPERT
1022 This option is required by programs like Wine to run 16-bit
1023 protected mode legacy code on x86 processors. Disabling
1024 this option saves about 300 bytes on i386, or around 6K text
1025 plus 16K runtime memory on x86-64,
1029 depends on X86_16BIT && X86_32
1033 depends on X86_16BIT && X86_64
1035 config X86_VSYSCALL_EMULATION
1036 bool "Enable vsyscall emulation" if EXPERT
1040 This enables emulation of the legacy vsyscall page. Disabling
1041 it is roughly equivalent to booting with vsyscall=none, except
1042 that it will also disable the helpful warning if a program
1043 tries to use a vsyscall. With this option set to N, offending
1044 programs will just segfault, citing addresses of the form
1047 This option is required by many programs built before 2013, and
1048 care should be used even with newer programs if set to N.
1050 Disabling this option saves about 7K of kernel size and
1051 possibly 4K of additional runtime pagetable memory.
1054 tristate "Toshiba Laptop support"
1057 This adds a driver to safely access the System Management Mode of
1058 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1059 not work on models with a Phoenix BIOS. The System Management Mode
1060 is used to set the BIOS and power saving options on Toshiba portables.
1062 For information on utilities to make use of this driver see the
1063 Toshiba Linux utilities web site at:
1064 <http://www.buzzard.org.uk/toshiba/>.
1066 Say Y if you intend to run this kernel on a Toshiba portable.
1070 tristate "Dell laptop support"
1073 This adds a driver to safely access the System Management Mode
1074 of the CPU on the Dell Inspiron 8000. The System Management Mode
1075 is used to read cpu temperature and cooling fan status and to
1076 control the fans on the I8K portables.
1078 This driver has been tested only on the Inspiron 8000 but it may
1079 also work with other Dell laptops. You can force loading on other
1080 models by passing the parameter `force=1' to the module. Use at
1083 For information on utilities to make use of this driver see the
1084 I8K Linux utilities web site at:
1085 <http://people.debian.org/~dz/i8k/>
1087 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1090 config X86_REBOOTFIXUPS
1091 bool "Enable X86 board specific fixups for reboot"
1094 This enables chipset and/or board specific fixups to be done
1095 in order to get reboot to work correctly. This is only needed on
1096 some combinations of hardware and BIOS. The symptom, for which
1097 this config is intended, is when reboot ends with a stalled/hung
1100 Currently, the only fixup is for the Geode machines using
1101 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1103 Say Y if you want to enable the fixup. Currently, it's safe to
1104 enable this option even if you don't need it.
1108 tristate "CPU microcode loading support"
1109 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1113 If you say Y here, you will be able to update the microcode on
1114 certain Intel and AMD processors. The Intel support is for the
1115 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1116 Xeon etc. The AMD support is for families 0x10 and later. You will
1117 obviously need the actual microcode binary data itself which is not
1118 shipped with the Linux kernel.
1120 This option selects the general module only, you need to select
1121 at least one vendor specific module as well.
1123 To compile this driver as a module, choose M here: the module
1124 will be called microcode.
1126 config MICROCODE_INTEL
1127 bool "Intel microcode loading support"
1128 depends on MICROCODE
1132 This options enables microcode patch loading support for Intel
1135 For the current Intel microcode data package go to
1136 <https://downloadcenter.intel.com> and search for
1137 'Linux Processor Microcode Data File'.
1139 config MICROCODE_AMD
1140 bool "AMD microcode loading support"
1141 depends on MICROCODE
1144 If you select this option, microcode patch loading support for AMD
1145 processors will be enabled.
1147 config MICROCODE_OLD_INTERFACE
1149 depends on MICROCODE
1151 config MICROCODE_INTEL_EARLY
1154 config MICROCODE_AMD_EARLY
1157 config MICROCODE_EARLY
1158 bool "Early load microcode"
1159 depends on MICROCODE=y && BLK_DEV_INITRD
1160 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1161 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1164 This option provides functionality to read additional microcode data
1165 at the beginning of initrd image. The data tells kernel to load
1166 microcode to CPU's as early as possible. No functional change if no
1167 microcode data is glued to the initrd, therefore it's safe to say Y.
1170 tristate "/dev/cpu/*/msr - Model-specific register support"
1172 This device gives privileged processes access to the x86
1173 Model-Specific Registers (MSRs). It is a character device with
1174 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1175 MSR accesses are directed to a specific CPU on multi-processor
1179 tristate "/dev/cpu/*/cpuid - CPU information support"
1181 This device gives processes access to the x86 CPUID instruction to
1182 be executed on a specific processor. It is a character device
1183 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1187 prompt "High Memory Support"
1194 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1195 However, the address space of 32-bit x86 processors is only 4
1196 Gigabytes large. That means that, if you have a large amount of
1197 physical memory, not all of it can be "permanently mapped" by the
1198 kernel. The physical memory that's not permanently mapped is called
1201 If you are compiling a kernel which will never run on a machine with
1202 more than 1 Gigabyte total physical RAM, answer "off" here (default
1203 choice and suitable for most users). This will result in a "3GB/1GB"
1204 split: 3GB are mapped so that each process sees a 3GB virtual memory
1205 space and the remaining part of the 4GB virtual memory space is used
1206 by the kernel to permanently map as much physical memory as
1209 If the machine has between 1 and 4 Gigabytes physical RAM, then
1212 If more than 4 Gigabytes is used then answer "64GB" here. This
1213 selection turns Intel PAE (Physical Address Extension) mode on.
1214 PAE implements 3-level paging on IA32 processors. PAE is fully
1215 supported by Linux, PAE mode is implemented on all recent Intel
1216 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1217 then the kernel will not boot on CPUs that don't support PAE!
1219 The actual amount of total physical memory will either be
1220 auto detected or can be forced by using a kernel command line option
1221 such as "mem=256M". (Try "man bootparam" or see the documentation of
1222 your boot loader (lilo or loadlin) about how to pass options to the
1223 kernel at boot time.)
1225 If unsure, say "off".
1230 Select this if you have a 32-bit processor and between 1 and 4
1231 gigabytes of physical RAM.
1238 Select this if you have a 32-bit processor and more than 4
1239 gigabytes of physical RAM.
1244 prompt "Memory split" if EXPERT
1248 Select the desired split between kernel and user memory.
1250 If the address range available to the kernel is less than the
1251 physical memory installed, the remaining memory will be available
1252 as "high memory". Accessing high memory is a little more costly
1253 than low memory, as it needs to be mapped into the kernel first.
1254 Note that increasing the kernel address space limits the range
1255 available to user programs, making the address space there
1256 tighter. Selecting anything other than the default 3G/1G split
1257 will also likely make your kernel incompatible with binary-only
1260 If you are not absolutely sure what you are doing, leave this
1264 bool "3G/1G user/kernel split"
1265 config VMSPLIT_3G_OPT
1267 bool "3G/1G user/kernel split (for full 1G low memory)"
1269 bool "2G/2G user/kernel split"
1270 config VMSPLIT_2G_OPT
1272 bool "2G/2G user/kernel split (for full 2G low memory)"
1274 bool "1G/3G user/kernel split"
1279 default 0xB0000000 if VMSPLIT_3G_OPT
1280 default 0x80000000 if VMSPLIT_2G
1281 default 0x78000000 if VMSPLIT_2G_OPT
1282 default 0x40000000 if VMSPLIT_1G
1288 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1291 bool "PAE (Physical Address Extension) Support"
1292 depends on X86_32 && !HIGHMEM4G
1294 PAE is required for NX support, and furthermore enables
1295 larger swapspace support for non-overcommit purposes. It
1296 has the cost of more pagetable lookup overhead, and also
1297 consumes more pagetable space per process.
1299 config ARCH_PHYS_ADDR_T_64BIT
1301 depends on X86_64 || X86_PAE
1303 config ARCH_DMA_ADDR_T_64BIT
1305 depends on X86_64 || HIGHMEM64G
1307 config DIRECT_GBPAGES
1308 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1312 Allow the kernel linear mapping to use 1GB pages on CPUs that
1313 support it. This can improve the kernel's performance a tiny bit by
1314 reducing TLB pressure. If in doubt, say "Y".
1316 # Common NUMA Features
1318 bool "Numa Memory Allocation and Scheduler Support"
1320 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1321 default y if X86_BIGSMP
1323 Enable NUMA (Non Uniform Memory Access) support.
1325 The kernel will try to allocate memory used by a CPU on the
1326 local memory controller of the CPU and add some more
1327 NUMA awareness to the kernel.
1329 For 64-bit this is recommended if the system is Intel Core i7
1330 (or later), AMD Opteron, or EM64T NUMA.
1332 For 32-bit this is only needed if you boot a 32-bit
1333 kernel on a 64-bit NUMA platform.
1335 Otherwise, you should say N.
1339 prompt "Old style AMD Opteron NUMA detection"
1340 depends on X86_64 && NUMA && PCI
1342 Enable AMD NUMA node topology detection. You should say Y here if
1343 you have a multi processor AMD system. This uses an old method to
1344 read the NUMA configuration directly from the builtin Northbridge
1345 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1346 which also takes priority if both are compiled in.
1348 config X86_64_ACPI_NUMA
1350 prompt "ACPI NUMA detection"
1351 depends on X86_64 && NUMA && ACPI && PCI
1354 Enable ACPI SRAT based node topology detection.
1356 # Some NUMA nodes have memory ranges that span
1357 # other nodes. Even though a pfn is valid and
1358 # between a node's start and end pfns, it may not
1359 # reside on that node. See memmap_init_zone()
1361 config NODES_SPAN_OTHER_NODES
1363 depends on X86_64_ACPI_NUMA
1366 bool "NUMA emulation"
1369 Enable NUMA emulation. A flat machine will be split
1370 into virtual nodes when booted with "numa=fake=N", where N is the
1371 number of nodes. This is only useful for debugging.
1374 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1376 default "10" if MAXSMP
1377 default "6" if X86_64
1379 depends on NEED_MULTIPLE_NODES
1381 Specify the maximum number of NUMA Nodes available on the target
1382 system. Increases memory reserved to accommodate various tables.
1384 config ARCH_HAVE_MEMORY_PRESENT
1386 depends on X86_32 && DISCONTIGMEM
1388 config NEED_NODE_MEMMAP_SIZE
1390 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1392 config ARCH_FLATMEM_ENABLE
1394 depends on X86_32 && !NUMA
1396 config ARCH_DISCONTIGMEM_ENABLE
1398 depends on NUMA && X86_32
1400 config ARCH_DISCONTIGMEM_DEFAULT
1402 depends on NUMA && X86_32
1404 config ARCH_SPARSEMEM_ENABLE
1406 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1407 select SPARSEMEM_STATIC if X86_32
1408 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1410 config ARCH_SPARSEMEM_DEFAULT
1414 config ARCH_SELECT_MEMORY_MODEL
1416 depends on ARCH_SPARSEMEM_ENABLE
1418 config ARCH_MEMORY_PROBE
1419 bool "Enable sysfs memory/probe interface"
1420 depends on X86_64 && MEMORY_HOTPLUG
1422 This option enables a sysfs memory/probe interface for testing.
1423 See Documentation/memory-hotplug.txt for more information.
1424 If you are unsure how to answer this question, answer N.
1426 config ARCH_PROC_KCORE_TEXT
1428 depends on X86_64 && PROC_KCORE
1430 config ILLEGAL_POINTER_VALUE
1433 default 0xdead000000000000 if X86_64
1438 bool "Allocate 3rd-level pagetables from highmem"
1441 The VM uses one page table entry for each page of physical memory.
1442 For systems with a lot of RAM, this can be wasteful of precious
1443 low memory. Setting this option will put user-space page table
1444 entries in high memory.
1446 config X86_CHECK_BIOS_CORRUPTION
1447 bool "Check for low memory corruption"
1449 Periodically check for memory corruption in low memory, which
1450 is suspected to be caused by BIOS. Even when enabled in the
1451 configuration, it is disabled at runtime. Enable it by
1452 setting "memory_corruption_check=1" on the kernel command
1453 line. By default it scans the low 64k of memory every 60
1454 seconds; see the memory_corruption_check_size and
1455 memory_corruption_check_period parameters in
1456 Documentation/kernel-parameters.txt to adjust this.
1458 When enabled with the default parameters, this option has
1459 almost no overhead, as it reserves a relatively small amount
1460 of memory and scans it infrequently. It both detects corruption
1461 and prevents it from affecting the running system.
1463 It is, however, intended as a diagnostic tool; if repeatable
1464 BIOS-originated corruption always affects the same memory,
1465 you can use memmap= to prevent the kernel from using that
1468 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1469 bool "Set the default setting of memory_corruption_check"
1470 depends on X86_CHECK_BIOS_CORRUPTION
1473 Set whether the default state of memory_corruption_check is
1476 config X86_RESERVE_LOW
1477 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1481 Specify the amount of low memory to reserve for the BIOS.
1483 The first page contains BIOS data structures that the kernel
1484 must not use, so that page must always be reserved.
1486 By default we reserve the first 64K of physical RAM, as a
1487 number of BIOSes are known to corrupt that memory range
1488 during events such as suspend/resume or monitor cable
1489 insertion, so it must not be used by the kernel.
1491 You can set this to 4 if you are absolutely sure that you
1492 trust the BIOS to get all its memory reservations and usages
1493 right. If you know your BIOS have problems beyond the
1494 default 64K area, you can set this to 640 to avoid using the
1495 entire low memory range.
1497 If you have doubts about the BIOS (e.g. suspend/resume does
1498 not work or there's kernel crashes after certain hardware
1499 hotplug events) then you might want to enable
1500 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1501 typical corruption patterns.
1503 Leave this to the default value of 64 if you are unsure.
1505 config MATH_EMULATION
1507 prompt "Math emulation" if X86_32
1509 Linux can emulate a math coprocessor (used for floating point
1510 operations) if you don't have one. 486DX and Pentium processors have
1511 a math coprocessor built in, 486SX and 386 do not, unless you added
1512 a 487DX or 387, respectively. (The messages during boot time can
1513 give you some hints here ["man dmesg"].) Everyone needs either a
1514 coprocessor or this emulation.
1516 If you don't have a math coprocessor, you need to say Y here; if you
1517 say Y here even though you have a coprocessor, the coprocessor will
1518 be used nevertheless. (This behavior can be changed with the kernel
1519 command line option "no387", which comes handy if your coprocessor
1520 is broken. Try "man bootparam" or see the documentation of your boot
1521 loader (lilo or loadlin) about how to pass options to the kernel at
1522 boot time.) This means that it is a good idea to say Y here if you
1523 intend to use this kernel on different machines.
1525 More information about the internals of the Linux math coprocessor
1526 emulation can be found in <file:arch/x86/math-emu/README>.
1528 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1529 kernel, it won't hurt.
1533 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1535 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1536 the Memory Type Range Registers (MTRRs) may be used to control
1537 processor access to memory ranges. This is most useful if you have
1538 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1539 allows bus write transfers to be combined into a larger transfer
1540 before bursting over the PCI/AGP bus. This can increase performance
1541 of image write operations 2.5 times or more. Saying Y here creates a
1542 /proc/mtrr file which may be used to manipulate your processor's
1543 MTRRs. Typically the X server should use this.
1545 This code has a reasonably generic interface so that similar
1546 control registers on other processors can be easily supported
1549 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1550 Registers (ARRs) which provide a similar functionality to MTRRs. For
1551 these, the ARRs are used to emulate the MTRRs.
1552 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1553 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1554 write-combining. All of these processors are supported by this code
1555 and it makes sense to say Y here if you have one of them.
1557 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1558 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1559 can lead to all sorts of problems, so it's good to say Y here.
1561 You can safely say Y even if your machine doesn't have MTRRs, you'll
1562 just add about 9 KB to your kernel.
1564 See <file:Documentation/x86/mtrr.txt> for more information.
1566 config MTRR_SANITIZER
1568 prompt "MTRR cleanup support"
1571 Convert MTRR layout from continuous to discrete, so X drivers can
1572 add writeback entries.
1574 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1575 The largest mtrr entry size for a continuous block can be set with
1580 config MTRR_SANITIZER_ENABLE_DEFAULT
1581 int "MTRR cleanup enable value (0-1)"
1584 depends on MTRR_SANITIZER
1586 Enable mtrr cleanup default value
1588 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1589 int "MTRR cleanup spare reg num (0-7)"
1592 depends on MTRR_SANITIZER
1594 mtrr cleanup spare entries default, it can be changed via
1595 mtrr_spare_reg_nr=N on the kernel command line.
1599 prompt "x86 PAT support" if EXPERT
1602 Use PAT attributes to setup page level cache control.
1604 PATs are the modern equivalents of MTRRs and are much more
1605 flexible than MTRRs.
1607 Say N here if you see bootup problems (boot crash, boot hang,
1608 spontaneous reboots) or a non-working video driver.
1612 config ARCH_USES_PG_UNCACHED
1618 prompt "x86 architectural random number generator" if EXPERT
1620 Enable the x86 architectural RDRAND instruction
1621 (Intel Bull Mountain technology) to generate random numbers.
1622 If supported, this is a high bandwidth, cryptographically
1623 secure hardware random number generator.
1627 prompt "Supervisor Mode Access Prevention" if EXPERT
1629 Supervisor Mode Access Prevention (SMAP) is a security
1630 feature in newer Intel processors. There is a small
1631 performance cost if this enabled and turned on; there is
1632 also a small increase in the kernel size if this is enabled.
1636 config X86_INTEL_MPX
1637 prompt "Intel MPX (Memory Protection Extensions)"
1639 depends on CPU_SUP_INTEL
1641 MPX provides hardware features that can be used in
1642 conjunction with compiler-instrumented code to check
1643 memory references. It is designed to detect buffer
1644 overflow or underflow bugs.
1646 This option enables running applications which are
1647 instrumented or otherwise use MPX. It does not use MPX
1648 itself inside the kernel or to protect the kernel
1649 against bad memory references.
1651 Enabling this option will make the kernel larger:
1652 ~8k of kernel text and 36 bytes of data on a 64-bit
1653 defconfig. It adds a long to the 'mm_struct' which
1654 will increase the kernel memory overhead of each
1655 process and adds some branches to paths used during
1656 exec() and munmap().
1658 For details, see Documentation/x86/intel_mpx.txt
1663 bool "EFI runtime service support"
1666 select EFI_RUNTIME_WRAPPERS
1668 This enables the kernel to use EFI runtime services that are
1669 available (such as the EFI variable services).
1671 This option is only useful on systems that have EFI firmware.
1672 In addition, you should use the latest ELILO loader available
1673 at <http://elilo.sourceforge.net> in order to take advantage
1674 of EFI runtime services. However, even with this option, the
1675 resultant kernel should continue to boot on existing non-EFI
1679 bool "EFI stub support"
1680 depends on EFI && !X86_USE_3DNOW
1683 This kernel feature allows a bzImage to be loaded directly
1684 by EFI firmware without the use of a bootloader.
1686 See Documentation/efi-stub.txt for more information.
1689 bool "EFI mixed-mode support"
1690 depends on EFI_STUB && X86_64
1692 Enabling this feature allows a 64-bit kernel to be booted
1693 on a 32-bit firmware, provided that your CPU supports 64-bit
1696 Note that it is not possible to boot a mixed-mode enabled
1697 kernel via the EFI boot stub - a bootloader that supports
1698 the EFI handover protocol must be used.
1704 prompt "Enable seccomp to safely compute untrusted bytecode"
1706 This kernel feature is useful for number crunching applications
1707 that may need to compute untrusted bytecode during their
1708 execution. By using pipes or other transports made available to
1709 the process as file descriptors supporting the read/write
1710 syscalls, it's possible to isolate those applications in
1711 their own address space using seccomp. Once seccomp is
1712 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1713 and the task is only allowed to execute a few safe syscalls
1714 defined by each seccomp mode.
1716 If unsure, say Y. Only embedded should say N here.
1718 source kernel/Kconfig.hz
1721 bool "kexec system call"
1723 kexec is a system call that implements the ability to shutdown your
1724 current kernel, and to start another kernel. It is like a reboot
1725 but it is independent of the system firmware. And like a reboot
1726 you can start any kernel with it, not just Linux.
1728 The name comes from the similarity to the exec system call.
1730 It is an ongoing process to be certain the hardware in a machine
1731 is properly shutdown, so do not be surprised if this code does not
1732 initially work for you. As of this writing the exact hardware
1733 interface is strongly in flux, so no good recommendation can be
1737 bool "kexec file based system call"
1742 depends on CRYPTO_SHA256=y
1744 This is new version of kexec system call. This system call is
1745 file based and takes file descriptors as system call argument
1746 for kernel and initramfs as opposed to list of segments as
1747 accepted by previous system call.
1749 config KEXEC_VERIFY_SIG
1750 bool "Verify kernel signature during kexec_file_load() syscall"
1751 depends on KEXEC_FILE
1753 This option makes kernel signature verification mandatory for
1754 kexec_file_load() syscall. If kernel is signature can not be
1755 verified, kexec_file_load() will fail.
1757 This option enforces signature verification at generic level.
1758 One needs to enable signature verification for type of kernel
1759 image being loaded to make sure it works. For example, enable
1760 bzImage signature verification option to be able to load and
1761 verify signatures of bzImage. Otherwise kernel loading will fail.
1763 config KEXEC_BZIMAGE_VERIFY_SIG
1764 bool "Enable bzImage signature verification support"
1765 depends on KEXEC_VERIFY_SIG
1766 depends on SIGNED_PE_FILE_VERIFICATION
1767 select SYSTEM_TRUSTED_KEYRING
1769 Enable bzImage signature verification support.
1772 bool "kernel crash dumps"
1773 depends on X86_64 || (X86_32 && HIGHMEM)
1775 Generate crash dump after being started by kexec.
1776 This should be normally only set in special crash dump kernels
1777 which are loaded in the main kernel with kexec-tools into
1778 a specially reserved region and then later executed after
1779 a crash by kdump/kexec. The crash dump kernel must be compiled
1780 to a memory address not used by the main kernel or BIOS using
1781 PHYSICAL_START, or it must be built as a relocatable image
1782 (CONFIG_RELOCATABLE=y).
1783 For more details see Documentation/kdump/kdump.txt
1787 depends on KEXEC && HIBERNATION
1789 Jump between original kernel and kexeced kernel and invoke
1790 code in physical address mode via KEXEC
1792 config PHYSICAL_START
1793 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1796 This gives the physical address where the kernel is loaded.
1798 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1799 bzImage will decompress itself to above physical address and
1800 run from there. Otherwise, bzImage will run from the address where
1801 it has been loaded by the boot loader and will ignore above physical
1804 In normal kdump cases one does not have to set/change this option
1805 as now bzImage can be compiled as a completely relocatable image
1806 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1807 address. This option is mainly useful for the folks who don't want
1808 to use a bzImage for capturing the crash dump and want to use a
1809 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1810 to be specifically compiled to run from a specific memory area
1811 (normally a reserved region) and this option comes handy.
1813 So if you are using bzImage for capturing the crash dump,
1814 leave the value here unchanged to 0x1000000 and set
1815 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1816 for capturing the crash dump change this value to start of
1817 the reserved region. In other words, it can be set based on
1818 the "X" value as specified in the "crashkernel=YM@XM"
1819 command line boot parameter passed to the panic-ed
1820 kernel. Please take a look at Documentation/kdump/kdump.txt
1821 for more details about crash dumps.
1823 Usage of bzImage for capturing the crash dump is recommended as
1824 one does not have to build two kernels. Same kernel can be used
1825 as production kernel and capture kernel. Above option should have
1826 gone away after relocatable bzImage support is introduced. But it
1827 is present because there are users out there who continue to use
1828 vmlinux for dump capture. This option should go away down the
1831 Don't change this unless you know what you are doing.
1834 bool "Build a relocatable kernel"
1837 This builds a kernel image that retains relocation information
1838 so it can be loaded someplace besides the default 1MB.
1839 The relocations tend to make the kernel binary about 10% larger,
1840 but are discarded at runtime.
1842 One use is for the kexec on panic case where the recovery kernel
1843 must live at a different physical address than the primary
1846 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1847 it has been loaded at and the compile time physical address
1848 (CONFIG_PHYSICAL_START) is used as the minimum location.
1850 config RANDOMIZE_BASE
1851 bool "Randomize the address of the kernel image"
1852 depends on RELOCATABLE
1855 Randomizes the physical and virtual address at which the
1856 kernel image is decompressed, as a security feature that
1857 deters exploit attempts relying on knowledge of the location
1858 of kernel internals.
1860 Entropy is generated using the RDRAND instruction if it is
1861 supported. If RDTSC is supported, it is used as well. If
1862 neither RDRAND nor RDTSC are supported, then randomness is
1863 read from the i8254 timer.
1865 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1866 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1867 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1868 minimum of 2MiB, only 10 bits of entropy is theoretically
1869 possible. At best, due to page table layouts, 64-bit can use
1870 9 bits of entropy and 32-bit uses 8 bits.
1874 config RANDOMIZE_BASE_MAX_OFFSET
1875 hex "Maximum kASLR offset allowed" if EXPERT
1876 depends on RANDOMIZE_BASE
1877 range 0x0 0x20000000 if X86_32
1878 default "0x20000000" if X86_32
1879 range 0x0 0x40000000 if X86_64
1880 default "0x40000000" if X86_64
1882 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1883 memory is used to determine the maximal offset in bytes that will
1884 be applied to the kernel when kernel Address Space Layout
1885 Randomization (kASLR) is active. This must be a multiple of
1888 On 32-bit this is limited to 512MiB by page table layouts. The
1891 On 64-bit this is limited by how the kernel fixmap page table is
1892 positioned, so this cannot be larger than 1GiB currently. Without
1893 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1894 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1895 modules area will shrink to compensate, up to the current maximum
1896 1GiB to 1GiB split. The default is 1GiB.
1898 If unsure, leave at the default value.
1900 # Relocation on x86 needs some additional build support
1901 config X86_NEED_RELOCS
1903 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1905 config PHYSICAL_ALIGN
1906 hex "Alignment value to which kernel should be aligned"
1908 range 0x2000 0x1000000 if X86_32
1909 range 0x200000 0x1000000 if X86_64
1911 This value puts the alignment restrictions on physical address
1912 where kernel is loaded and run from. Kernel is compiled for an
1913 address which meets above alignment restriction.
1915 If bootloader loads the kernel at a non-aligned address and
1916 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1917 address aligned to above value and run from there.
1919 If bootloader loads the kernel at a non-aligned address and
1920 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1921 load address and decompress itself to the address it has been
1922 compiled for and run from there. The address for which kernel is
1923 compiled already meets above alignment restrictions. Hence the
1924 end result is that kernel runs from a physical address meeting
1925 above alignment restrictions.
1927 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1928 this value must be a multiple of 0x200000.
1930 Don't change this unless you know what you are doing.
1933 bool "Support for hot-pluggable CPUs"
1936 Say Y here to allow turning CPUs off and on. CPUs can be
1937 controlled through /sys/devices/system/cpu.
1938 ( Note: power management support will enable this option
1939 automatically on SMP systems. )
1940 Say N if you want to disable CPU hotplug.
1942 config BOOTPARAM_HOTPLUG_CPU0
1943 bool "Set default setting of cpu0_hotpluggable"
1945 depends on HOTPLUG_CPU
1947 Set whether default state of cpu0_hotpluggable is on or off.
1949 Say Y here to enable CPU0 hotplug by default. If this switch
1950 is turned on, there is no need to give cpu0_hotplug kernel
1951 parameter and the CPU0 hotplug feature is enabled by default.
1953 Please note: there are two known CPU0 dependencies if you want
1954 to enable the CPU0 hotplug feature either by this switch or by
1955 cpu0_hotplug kernel parameter.
1957 First, resume from hibernate or suspend always starts from CPU0.
1958 So hibernate and suspend are prevented if CPU0 is offline.
1960 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1961 offline if any interrupt can not migrate out of CPU0. There may
1962 be other CPU0 dependencies.
1964 Please make sure the dependencies are under your control before
1965 you enable this feature.
1967 Say N if you don't want to enable CPU0 hotplug feature by default.
1968 You still can enable the CPU0 hotplug feature at boot by kernel
1969 parameter cpu0_hotplug.
1971 config DEBUG_HOTPLUG_CPU0
1973 prompt "Debug CPU0 hotplug"
1974 depends on HOTPLUG_CPU
1976 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1977 soon as possible and boots up userspace with CPU0 offlined. User
1978 can online CPU0 back after boot time.
1980 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1981 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1982 compilation or giving cpu0_hotplug kernel parameter at boot.
1988 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1989 depends on X86_32 || IA32_EMULATION
1991 Certain buggy versions of glibc will crash if they are
1992 presented with a 32-bit vDSO that is not mapped at the address
1993 indicated in its segment table.
1995 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1996 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1997 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1998 the only released version with the bug, but OpenSUSE 9
1999 contains a buggy "glibc 2.3.2".
2001 The symptom of the bug is that everything crashes on startup, saying:
2002 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2004 Saying Y here changes the default value of the vdso32 boot
2005 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2006 This works around the glibc bug but hurts performance.
2008 If unsure, say N: if you are compiling your own kernel, you
2009 are unlikely to be using a buggy version of glibc.
2012 bool "Built-in kernel command line"
2014 Allow for specifying boot arguments to the kernel at
2015 build time. On some systems (e.g. embedded ones), it is
2016 necessary or convenient to provide some or all of the
2017 kernel boot arguments with the kernel itself (that is,
2018 to not rely on the boot loader to provide them.)
2020 To compile command line arguments into the kernel,
2021 set this option to 'Y', then fill in the
2022 the boot arguments in CONFIG_CMDLINE.
2024 Systems with fully functional boot loaders (i.e. non-embedded)
2025 should leave this option set to 'N'.
2028 string "Built-in kernel command string"
2029 depends on CMDLINE_BOOL
2032 Enter arguments here that should be compiled into the kernel
2033 image and used at boot time. If the boot loader provides a
2034 command line at boot time, it is appended to this string to
2035 form the full kernel command line, when the system boots.
2037 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2038 change this behavior.
2040 In most cases, the command line (whether built-in or provided
2041 by the boot loader) should specify the device for the root
2044 config CMDLINE_OVERRIDE
2045 bool "Built-in command line overrides boot loader arguments"
2046 depends on CMDLINE_BOOL
2048 Set this option to 'Y' to have the kernel ignore the boot loader
2049 command line, and use ONLY the built-in command line.
2051 This is used to work around broken boot loaders. This should
2052 be set to 'N' under normal conditions.
2054 source "kernel/livepatch/Kconfig"
2058 config ARCH_ENABLE_MEMORY_HOTPLUG
2060 depends on X86_64 || (X86_32 && HIGHMEM)
2062 config ARCH_ENABLE_MEMORY_HOTREMOVE
2064 depends on MEMORY_HOTPLUG
2066 config USE_PERCPU_NUMA_NODE_ID
2070 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2072 depends on X86_64 || X86_PAE
2074 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2076 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2078 menu "Power management and ACPI options"
2080 config ARCH_HIBERNATION_HEADER
2082 depends on X86_64 && HIBERNATION
2084 source "kernel/power/Kconfig"
2086 source "drivers/acpi/Kconfig"
2088 source "drivers/sfi/Kconfig"
2095 tristate "APM (Advanced Power Management) BIOS support"
2096 depends on X86_32 && PM_SLEEP
2098 APM is a BIOS specification for saving power using several different
2099 techniques. This is mostly useful for battery powered laptops with
2100 APM compliant BIOSes. If you say Y here, the system time will be
2101 reset after a RESUME operation, the /proc/apm device will provide
2102 battery status information, and user-space programs will receive
2103 notification of APM "events" (e.g. battery status change).
2105 If you select "Y" here, you can disable actual use of the APM
2106 BIOS by passing the "apm=off" option to the kernel at boot time.
2108 Note that the APM support is almost completely disabled for
2109 machines with more than one CPU.
2111 In order to use APM, you will need supporting software. For location
2112 and more information, read <file:Documentation/power/apm-acpi.txt>
2113 and the Battery Powered Linux mini-HOWTO, available from
2114 <http://www.tldp.org/docs.html#howto>.
2116 This driver does not spin down disk drives (see the hdparm(8)
2117 manpage ("man 8 hdparm") for that), and it doesn't turn off
2118 VESA-compliant "green" monitors.
2120 This driver does not support the TI 4000M TravelMate and the ACER
2121 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2122 desktop machines also don't have compliant BIOSes, and this driver
2123 may cause those machines to panic during the boot phase.
2125 Generally, if you don't have a battery in your machine, there isn't
2126 much point in using this driver and you should say N. If you get
2127 random kernel OOPSes or reboots that don't seem to be related to
2128 anything, try disabling/enabling this option (or disabling/enabling
2131 Some other things you should try when experiencing seemingly random,
2134 1) make sure that you have enough swap space and that it is
2136 2) pass the "no-hlt" option to the kernel
2137 3) switch on floating point emulation in the kernel and pass
2138 the "no387" option to the kernel
2139 4) pass the "floppy=nodma" option to the kernel
2140 5) pass the "mem=4M" option to the kernel (thereby disabling
2141 all but the first 4 MB of RAM)
2142 6) make sure that the CPU is not over clocked.
2143 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2144 8) disable the cache from your BIOS settings
2145 9) install a fan for the video card or exchange video RAM
2146 10) install a better fan for the CPU
2147 11) exchange RAM chips
2148 12) exchange the motherboard.
2150 To compile this driver as a module, choose M here: the
2151 module will be called apm.
2155 config APM_IGNORE_USER_SUSPEND
2156 bool "Ignore USER SUSPEND"
2158 This option will ignore USER SUSPEND requests. On machines with a
2159 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2160 series notebooks, it is necessary to say Y because of a BIOS bug.
2162 config APM_DO_ENABLE
2163 bool "Enable PM at boot time"
2165 Enable APM features at boot time. From page 36 of the APM BIOS
2166 specification: "When disabled, the APM BIOS does not automatically
2167 power manage devices, enter the Standby State, enter the Suspend
2168 State, or take power saving steps in response to CPU Idle calls."
2169 This driver will make CPU Idle calls when Linux is idle (unless this
2170 feature is turned off -- see "Do CPU IDLE calls", below). This
2171 should always save battery power, but more complicated APM features
2172 will be dependent on your BIOS implementation. You may need to turn
2173 this option off if your computer hangs at boot time when using APM
2174 support, or if it beeps continuously instead of suspending. Turn
2175 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2176 T400CDT. This is off by default since most machines do fine without
2181 bool "Make CPU Idle calls when idle"
2183 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2184 On some machines, this can activate improved power savings, such as
2185 a slowed CPU clock rate, when the machine is idle. These idle calls
2186 are made after the idle loop has run for some length of time (e.g.,
2187 333 mS). On some machines, this will cause a hang at boot time or
2188 whenever the CPU becomes idle. (On machines with more than one CPU,
2189 this option does nothing.)
2191 config APM_DISPLAY_BLANK
2192 bool "Enable console blanking using APM"
2194 Enable console blanking using the APM. Some laptops can use this to
2195 turn off the LCD backlight when the screen blanker of the Linux
2196 virtual console blanks the screen. Note that this is only used by
2197 the virtual console screen blanker, and won't turn off the backlight
2198 when using the X Window system. This also doesn't have anything to
2199 do with your VESA-compliant power-saving monitor. Further, this
2200 option doesn't work for all laptops -- it might not turn off your
2201 backlight at all, or it might print a lot of errors to the console,
2202 especially if you are using gpm.
2204 config APM_ALLOW_INTS
2205 bool "Allow interrupts during APM BIOS calls"
2207 Normally we disable external interrupts while we are making calls to
2208 the APM BIOS as a measure to lessen the effects of a badly behaving
2209 BIOS implementation. The BIOS should reenable interrupts if it
2210 needs to. Unfortunately, some BIOSes do not -- especially those in
2211 many of the newer IBM Thinkpads. If you experience hangs when you
2212 suspend, try setting this to Y. Otherwise, say N.
2216 source "drivers/cpufreq/Kconfig"
2218 source "drivers/cpuidle/Kconfig"
2220 source "drivers/idle/Kconfig"
2225 menu "Bus options (PCI etc.)"
2231 Find out whether you have a PCI motherboard. PCI is the name of a
2232 bus system, i.e. the way the CPU talks to the other stuff inside
2233 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2234 VESA. If you have PCI, say Y, otherwise N.
2237 prompt "PCI access mode"
2238 depends on X86_32 && PCI
2241 On PCI systems, the BIOS can be used to detect the PCI devices and
2242 determine their configuration. However, some old PCI motherboards
2243 have BIOS bugs and may crash if this is done. Also, some embedded
2244 PCI-based systems don't have any BIOS at all. Linux can also try to
2245 detect the PCI hardware directly without using the BIOS.
2247 With this option, you can specify how Linux should detect the
2248 PCI devices. If you choose "BIOS", the BIOS will be used,
2249 if you choose "Direct", the BIOS won't be used, and if you
2250 choose "MMConfig", then PCI Express MMCONFIG will be used.
2251 If you choose "Any", the kernel will try MMCONFIG, then the
2252 direct access method and falls back to the BIOS if that doesn't
2253 work. If unsure, go with the default, which is "Any".
2258 config PCI_GOMMCONFIG
2275 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2277 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2280 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2284 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2288 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2292 depends on PCI && XEN
2300 bool "Support mmconfig PCI config space access"
2301 depends on X86_64 && PCI && ACPI
2303 config PCI_CNB20LE_QUIRK
2304 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2307 Read the PCI windows out of the CNB20LE host bridge. This allows
2308 PCI hotplug to work on systems with the CNB20LE chipset which do
2311 There's no public spec for this chipset, and this functionality
2312 is known to be incomplete.
2314 You should say N unless you know you need this.
2316 source "drivers/pci/pcie/Kconfig"
2318 source "drivers/pci/Kconfig"
2320 # x86_64 have no ISA slots, but can have ISA-style DMA.
2322 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2325 Enables ISA-style DMA support for devices requiring such controllers.
2333 Find out whether you have ISA slots on your motherboard. ISA is the
2334 name of a bus system, i.e. the way the CPU talks to the other stuff
2335 inside your box. Other bus systems are PCI, EISA, MicroChannel
2336 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2337 newer boards don't support it. If you have ISA, say Y, otherwise N.
2343 The Extended Industry Standard Architecture (EISA) bus was
2344 developed as an open alternative to the IBM MicroChannel bus.
2346 The EISA bus provided some of the features of the IBM MicroChannel
2347 bus while maintaining backward compatibility with cards made for
2348 the older ISA bus. The EISA bus saw limited use between 1988 and
2349 1995 when it was made obsolete by the PCI bus.
2351 Say Y here if you are building a kernel for an EISA-based machine.
2355 source "drivers/eisa/Kconfig"
2358 tristate "NatSemi SCx200 support"
2360 This provides basic support for National Semiconductor's
2361 (now AMD's) Geode processors. The driver probes for the
2362 PCI-IDs of several on-chip devices, so its a good dependency
2363 for other scx200_* drivers.
2365 If compiled as a module, the driver is named scx200.
2367 config SCx200HR_TIMER
2368 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2372 This driver provides a clocksource built upon the on-chip
2373 27MHz high-resolution timer. Its also a workaround for
2374 NSC Geode SC-1100's buggy TSC, which loses time when the
2375 processor goes idle (as is done by the scheduler). The
2376 other workaround is idle=poll boot option.
2379 bool "One Laptop Per Child support"
2386 Add support for detecting the unique features of the OLPC
2390 bool "OLPC XO-1 Power Management"
2391 depends on OLPC && MFD_CS5535 && PM_SLEEP
2394 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2397 bool "OLPC XO-1 Real Time Clock"
2398 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2400 Add support for the XO-1 real time clock, which can be used as a
2401 programmable wakeup source.
2404 bool "OLPC XO-1 SCI extras"
2405 depends on OLPC && OLPC_XO1_PM
2411 Add support for SCI-based features of the OLPC XO-1 laptop:
2412 - EC-driven system wakeups
2416 - AC adapter status updates
2417 - Battery status updates
2419 config OLPC_XO15_SCI
2420 bool "OLPC XO-1.5 SCI extras"
2421 depends on OLPC && ACPI
2424 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2425 - EC-driven system wakeups
2426 - AC adapter status updates
2427 - Battery status updates
2430 bool "PCEngines ALIX System Support (LED setup)"
2433 This option enables system support for the PCEngines ALIX.
2434 At present this just sets up LEDs for GPIO control on
2435 ALIX2/3/6 boards. However, other system specific setup should
2438 Note: You must still enable the drivers for GPIO and LED support
2439 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2441 Note: You have to set alix.force=1 for boards with Award BIOS.
2444 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2447 This option enables system support for the Soekris Engineering net5501.
2450 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2454 This option enables system support for the Traverse Technologies GEOS.
2457 bool "Technologic Systems TS-5500 platform support"
2459 select CHECK_SIGNATURE
2463 This option enables system support for the Technologic Systems TS-5500.
2469 depends on CPU_SUP_AMD && PCI
2471 source "drivers/pcmcia/Kconfig"
2473 source "drivers/pci/hotplug/Kconfig"
2476 tristate "RapidIO support"
2480 If enabled this option will include drivers and the core
2481 infrastructure code to support RapidIO interconnect devices.
2483 source "drivers/rapidio/Kconfig"
2486 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2488 Firmwares often provide initial graphics framebuffers so the BIOS,
2489 bootloader or kernel can show basic video-output during boot for
2490 user-guidance and debugging. Historically, x86 used the VESA BIOS
2491 Extensions and EFI-framebuffers for this, which are mostly limited
2493 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2494 framebuffers so the new generic system-framebuffer drivers can be
2495 used on x86. If the framebuffer is not compatible with the generic
2496 modes, it is adverticed as fallback platform framebuffer so legacy
2497 drivers like efifb, vesafb and uvesafb can pick it up.
2498 If this option is not selected, all system framebuffers are always
2499 marked as fallback platform framebuffers as usual.
2501 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2502 not be able to pick up generic system framebuffers if this option
2503 is selected. You are highly encouraged to enable simplefb as
2504 replacement if you select this option. simplefb can correctly deal
2505 with generic system framebuffers. But you should still keep vesafb
2506 and others enabled as fallback if a system framebuffer is
2507 incompatible with simplefb.
2514 menu "Executable file formats / Emulations"
2516 source "fs/Kconfig.binfmt"
2518 config IA32_EMULATION
2519 bool "IA32 Emulation"
2522 select COMPAT_BINFMT_ELF
2525 Include code to run legacy 32-bit programs under a
2526 64-bit kernel. You should likely turn this on, unless you're
2527 100% sure that you don't have any 32-bit programs left.
2530 tristate "IA32 a.out support"
2531 depends on IA32_EMULATION
2533 Support old a.out binaries in the 32bit emulation.
2536 bool "x32 ABI for 64-bit mode"
2537 depends on X86_64 && IA32_EMULATION
2539 Include code to run binaries for the x32 native 32-bit ABI
2540 for 64-bit processors. An x32 process gets access to the
2541 full 64-bit register file and wide data path while leaving
2542 pointers at 32 bits for smaller memory footprint.
2544 You will need a recent binutils (2.22 or later) with
2545 elf32_x86_64 support enabled to compile a kernel with this
2550 depends on IA32_EMULATION || X86_X32
2551 select ARCH_WANT_OLD_COMPAT_IPC
2554 config COMPAT_FOR_U64_ALIGNMENT
2557 config SYSVIPC_COMPAT
2569 config HAVE_ATOMIC_IOMAP
2573 config X86_DEV_DMA_OPS
2575 depends on X86_64 || STA2X11
2577 config X86_DMA_REMAP
2585 source "net/Kconfig"
2587 source "drivers/Kconfig"
2589 source "drivers/firmware/Kconfig"
2593 source "arch/x86/Kconfig.debug"
2595 source "security/Kconfig"
2597 source "crypto/Kconfig"
2599 source "arch/x86/kvm/Kconfig"
2601 source "lib/Kconfig"