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 ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
27 select ARCH_HAS_FAST_MULTIPLIER
28 select ARCH_HAS_GCOV_PROFILE_ALL
29 select ARCH_MIGHT_HAVE_PC_PARPORT
30 select ARCH_MIGHT_HAVE_PC_SERIO
31 select HAVE_AOUT if X86_32
32 select HAVE_UNSTABLE_SCHED_CLOCK
33 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
34 select ARCH_SUPPORTS_INT128 if X86_64
37 select HAVE_PCSPKR_PLATFORM
38 select HAVE_PERF_EVENTS
39 select HAVE_IOREMAP_PROT
42 select HAVE_MEMBLOCK_NODE_MAP
43 select ARCH_DISCARD_MEMBLOCK
44 select ARCH_WANT_OPTIONAL_GPIOLIB
45 select ARCH_WANT_FRAME_POINTERS
47 select HAVE_DMA_CONTIGUOUS
48 select HAVE_KRETPROBES
49 select GENERIC_EARLY_IOREMAP
51 select HAVE_KPROBES_ON_FTRACE
52 select HAVE_FTRACE_MCOUNT_RECORD
53 select HAVE_FENTRY if X86_64
54 select HAVE_C_RECORDMCOUNT
55 select HAVE_DYNAMIC_FTRACE
56 select HAVE_DYNAMIC_FTRACE_WITH_REGS
57 select HAVE_FUNCTION_TRACER
58 select HAVE_FUNCTION_GRAPH_TRACER
59 select HAVE_FUNCTION_GRAPH_FP_TEST
60 select HAVE_SYSCALL_TRACEPOINTS
61 select SYSCTL_EXCEPTION_TRACE
64 select HAVE_ARCH_TRACEHOOK
65 select HAVE_GENERIC_DMA_COHERENT if X86_32
66 select HAVE_EFFICIENT_UNALIGNED_ACCESS
67 select USER_STACKTRACE_SUPPORT
68 select HAVE_REGS_AND_STACK_ACCESS_API
69 select HAVE_DMA_API_DEBUG
70 select HAVE_KERNEL_GZIP
71 select HAVE_KERNEL_BZIP2
72 select HAVE_KERNEL_LZMA
74 select HAVE_KERNEL_LZO
75 select HAVE_KERNEL_LZ4
76 select HAVE_HW_BREAKPOINT
77 select HAVE_MIXED_BREAKPOINTS_REGS
79 select HAVE_PERF_EVENTS_NMI
81 select HAVE_PERF_USER_STACK_DUMP
82 select HAVE_DEBUG_KMEMLEAK
84 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
85 select HAVE_CMPXCHG_LOCAL
86 select HAVE_CMPXCHG_DOUBLE
87 select HAVE_ARCH_KMEMCHECK
88 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
89 select HAVE_USER_RETURN_NOTIFIER
90 select ARCH_BINFMT_ELF_RANDOMIZE_PIE
91 select HAVE_ARCH_JUMP_LABEL
92 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
94 select GENERIC_FIND_FIRST_BIT
95 select GENERIC_IRQ_PROBE
96 select GENERIC_PENDING_IRQ if SMP
97 select GENERIC_IRQ_SHOW
98 select GENERIC_CLOCKEVENTS_MIN_ADJUST
99 select IRQ_FORCED_THREADING
100 select HAVE_BPF_JIT if X86_64
101 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
102 select ARCH_HAS_SG_CHAIN
104 select ARCH_HAVE_NMI_SAFE_CMPXCHG
106 select DCACHE_WORD_ACCESS
107 select GENERIC_SMP_IDLE_THREAD
108 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
109 select HAVE_ARCH_SECCOMP_FILTER
110 select BUILDTIME_EXTABLE_SORT
111 select GENERIC_CMOS_UPDATE
112 select HAVE_ARCH_SOFT_DIRTY if X86_64
113 select CLOCKSOURCE_WATCHDOG
114 select GENERIC_CLOCKEVENTS
115 select ARCH_CLOCKSOURCE_DATA
116 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
117 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
118 select GENERIC_TIME_VSYSCALL
119 select GENERIC_STRNCPY_FROM_USER
120 select GENERIC_STRNLEN_USER
121 select HAVE_CONTEXT_TRACKING if X86_64
122 select HAVE_IRQ_TIME_ACCOUNTING
124 select MODULES_USE_ELF_REL if X86_32
125 select MODULES_USE_ELF_RELA if X86_64
126 select CLONE_BACKWARDS if X86_32
127 select ARCH_USE_BUILTIN_BSWAP
128 select ARCH_USE_QUEUE_RWLOCK
129 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
130 select OLD_SIGACTION if X86_32
131 select COMPAT_OLD_SIGACTION if IA32_EMULATION
133 select HAVE_DEBUG_STACKOVERFLOW
134 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
135 select HAVE_CC_STACKPROTECTOR
136 select GENERIC_CPU_AUTOPROBE
137 select HAVE_ARCH_AUDITSYSCALL
138 select ARCH_SUPPORTS_ATOMIC_RMW
139 select HAVE_ACPI_APEI if ACPI
140 select HAVE_ACPI_APEI_NMI if ACPI
141 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
142 select X86_FEATURE_NAMES if PROC_FS
145 config INSTRUCTION_DECODER
147 depends on KPROBES || PERF_EVENTS || UPROBES
149 config PERF_EVENTS_INTEL_UNCORE
151 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
155 default "elf32-i386" if X86_32
156 default "elf64-x86-64" if X86_64
158 config ARCH_DEFCONFIG
160 default "arch/x86/configs/i386_defconfig" if X86_32
161 default "arch/x86/configs/x86_64_defconfig" if X86_64
163 config LOCKDEP_SUPPORT
166 config STACKTRACE_SUPPORT
169 config HAVE_LATENCYTOP_SUPPORT
178 config NEED_DMA_MAP_STATE
180 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG
182 config NEED_SG_DMA_LENGTH
185 config GENERIC_ISA_DMA
187 depends on ISA_DMA_API
192 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
194 config GENERIC_BUG_RELATIVE_POINTERS
197 config GENERIC_HWEIGHT
200 config ARCH_MAY_HAVE_PC_FDC
202 depends on ISA_DMA_API
204 config RWSEM_XCHGADD_ALGORITHM
207 config GENERIC_CALIBRATE_DELAY
210 config ARCH_HAS_CPU_RELAX
213 config ARCH_HAS_CACHE_LINE_SIZE
216 config HAVE_SETUP_PER_CPU_AREA
219 config NEED_PER_CPU_EMBED_FIRST_CHUNK
222 config NEED_PER_CPU_PAGE_FIRST_CHUNK
225 config ARCH_HIBERNATION_POSSIBLE
228 config ARCH_SUSPEND_POSSIBLE
231 config ARCH_WANT_HUGE_PMD_SHARE
234 config ARCH_WANT_GENERAL_HUGETLB
243 config ARCH_SUPPORTS_OPTIMIZED_INLINING
246 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
249 config HAVE_INTEL_TXT
251 depends on INTEL_IOMMU && ACPI
255 depends on X86_32 && SMP
259 depends on X86_64 && SMP
265 config X86_32_LAZY_GS
267 depends on X86_32 && !CC_STACKPROTECTOR
269 config ARCH_HWEIGHT_CFLAGS
271 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
272 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
274 config ARCH_SUPPORTS_UPROBES
277 config FIX_EARLYCON_MEM
280 source "init/Kconfig"
281 source "kernel/Kconfig.freezer"
283 menu "Processor type and features"
286 bool "DMA memory allocation support" if EXPERT
289 DMA memory allocation support allows devices with less than 32-bit
290 addressing to allocate within the first 16MB of address space.
291 Disable if no such devices will be used.
296 bool "Symmetric multi-processing support"
298 This enables support for systems with more than one CPU. If you have
299 a system with only one CPU, say N. If you have a system with more
302 If you say N here, the kernel will run on uni- and multiprocessor
303 machines, but will use only one CPU of a multiprocessor machine. If
304 you say Y here, the kernel will run on many, but not all,
305 uniprocessor machines. On a uniprocessor machine, the kernel
306 will run faster if you say N here.
308 Note that if you say Y here and choose architecture "586" or
309 "Pentium" under "Processor family", the kernel will not work on 486
310 architectures. Similarly, multiprocessor kernels for the "PPro"
311 architecture may not work on all Pentium based boards.
313 People using multiprocessor machines who say Y here should also say
314 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
315 Management" code will be disabled if you say Y here.
317 See also <file:Documentation/x86/i386/IO-APIC.txt>,
318 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
319 <http://www.tldp.org/docs.html#howto>.
321 If you don't know what to do here, say N.
323 config X86_FEATURE_NAMES
324 bool "Processor feature human-readable names" if EMBEDDED
327 This option compiles in a table of x86 feature bits and corresponding
328 names. This is required to support /proc/cpuinfo and a few kernel
329 messages. You can disable this to save space, at the expense of
330 making those few kernel messages show numeric feature bits instead.
335 bool "Support x2apic"
336 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
338 This enables x2apic support on CPUs that have this feature.
340 This allows 32-bit apic IDs (so it can support very large systems),
341 and accesses the local apic via MSRs not via mmio.
343 If you don't know what to do here, say N.
346 bool "Enable MPS table" if ACPI || SFI
348 depends on X86_LOCAL_APIC
350 For old smp systems that do not have proper acpi support. Newer systems
351 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
354 bool "Support for big SMP systems with more than 8 CPUs"
355 depends on X86_32 && SMP
357 This option is needed for the systems that have more than 8 CPUs
361 depends on X86_GOLDFISH
364 config X86_EXTENDED_PLATFORM
365 bool "Support for extended (non-PC) x86 platforms"
368 If you disable this option then the kernel will only support
369 standard PC platforms. (which covers the vast majority of
372 If you enable this option then you'll be able to select support
373 for the following (non-PC) 32 bit x86 platforms:
374 Goldfish (Android emulator)
377 SGI 320/540 (Visual Workstation)
378 STA2X11-based (e.g. Northville)
379 Moorestown MID devices
381 If you have one of these systems, or if you want to build a
382 generic distribution kernel, say Y here - otherwise say N.
386 config X86_EXTENDED_PLATFORM
387 bool "Support for extended (non-PC) x86 platforms"
390 If you disable this option then the kernel will only support
391 standard PC platforms. (which covers the vast majority of
394 If you enable this option then you'll be able to select support
395 for the following (non-PC) 64 bit x86 platforms:
400 If you have one of these systems, or if you want to build a
401 generic distribution kernel, say Y here - otherwise say N.
403 # This is an alphabetically sorted list of 64 bit extended platforms
404 # Please maintain the alphabetic order if and when there are additions
406 bool "Numascale NumaChip"
408 depends on X86_EXTENDED_PLATFORM
411 depends on X86_X2APIC
412 depends on PCI_MMCONFIG
414 Adds support for Numascale NumaChip large-SMP systems. Needed to
415 enable more than ~168 cores.
416 If you don't have one of these, you should say N here.
420 select HYPERVISOR_GUEST
422 depends on X86_64 && PCI
423 depends on X86_EXTENDED_PLATFORM
426 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
427 supposed to run on these EM64T-based machines. Only choose this option
428 if you have one of these machines.
431 bool "SGI Ultraviolet"
433 depends on X86_EXTENDED_PLATFORM
435 depends on X86_X2APIC
437 This option is needed in order to support SGI Ultraviolet systems.
438 If you don't have one of these, you should say N here.
440 # Following is an alphabetically sorted list of 32 bit extended platforms
441 # Please maintain the alphabetic order if and when there are additions
444 bool "Goldfish (Virtual Platform)"
445 depends on X86_EXTENDED_PLATFORM
447 Enable support for the Goldfish virtual platform used primarily
448 for Android development. Unless you are building for the Android
449 Goldfish emulator say N here.
452 bool "CE4100 TV platform"
454 depends on PCI_GODIRECT
455 depends on X86_IO_APIC
457 depends on X86_EXTENDED_PLATFORM
458 select X86_REBOOTFIXUPS
460 select OF_EARLY_FLATTREE
463 Select for the Intel CE media processor (CE4100) SOC.
464 This option compiles in support for the CE4100 SOC for settop
465 boxes and media devices.
468 bool "Intel MID platform support"
470 depends on X86_EXTENDED_PLATFORM
471 depends on X86_PLATFORM_DEVICES
474 depends on X86_IO_APIC
480 select MFD_INTEL_MSIC
482 Select to build a kernel capable of supporting Intel MID (Mobile
483 Internet Device) platform systems which do not have the PCI legacy
484 interfaces. If you are building for a PC class system say N here.
486 Intel MID platforms are based on an Intel processor and chipset which
487 consume less power than most of the x86 derivatives.
489 config X86_INTEL_QUARK
490 bool "Intel Quark platform support"
492 depends on X86_EXTENDED_PLATFORM
493 depends on X86_PLATFORM_DEVICES
497 depends on X86_IO_APIC
502 Select to include support for Quark X1000 SoC.
503 Say Y here if you have a Quark based system such as the Arduino
504 compatible Intel Galileo.
506 config X86_INTEL_LPSS
507 bool "Intel Low Power Subsystem Support"
512 Select to build support for Intel Low Power Subsystem such as
513 found on Intel Lynxpoint PCH. Selecting this option enables
514 things like clock tree (common clock framework) and pincontrol
515 which are needed by the LPSS peripheral drivers.
517 config X86_AMD_PLATFORM_DEVICE
518 bool "AMD ACPI2Platform devices support"
523 Select to interpret AMD specific ACPI device to platform device
524 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
525 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
526 implemented under PINCTRL subsystem.
529 tristate "Intel SoC IOSF Sideband support for SoC platforms"
532 This option enables sideband register access support for Intel SoC
533 platforms. On these platforms the IOSF sideband is used in lieu of
534 MSR's for some register accesses, mostly but not limited to thermal
535 and power. Drivers may query the availability of this device to
536 determine if they need the sideband in order to work on these
537 platforms. The sideband is available on the following SoC products.
538 This list is not meant to be exclusive.
543 You should say Y if you are running a kernel on one of these SoC's.
545 config IOSF_MBI_DEBUG
546 bool "Enable IOSF sideband access through debugfs"
547 depends on IOSF_MBI && DEBUG_FS
549 Select this option to expose the IOSF sideband access registers (MCR,
550 MDR, MCRX) through debugfs to write and read register information from
551 different units on the SoC. This is most useful for obtaining device
552 state information for debug and analysis. As this is a general access
553 mechanism, users of this option would have specific knowledge of the
554 device they want to access.
556 If you don't require the option or are in doubt, say N.
559 bool "RDC R-321x SoC"
561 depends on X86_EXTENDED_PLATFORM
563 select X86_REBOOTFIXUPS
565 This option is needed for RDC R-321x system-on-chip, also known
567 If you don't have one of these chips, you should say N here.
569 config X86_32_NON_STANDARD
570 bool "Support non-standard 32-bit SMP architectures"
571 depends on X86_32 && SMP
572 depends on X86_EXTENDED_PLATFORM
574 This option compiles in the bigsmp and STA2X11 default
575 subarchitectures. It is intended for a generic binary
576 kernel. If you select them all, kernel will probe it one by
577 one and will fallback to default.
579 # Alphabetically sorted list of Non standard 32 bit platforms
581 config X86_SUPPORTS_MEMORY_FAILURE
583 # MCE code calls memory_failure():
585 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
586 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
587 depends on X86_64 || !SPARSEMEM
588 select ARCH_SUPPORTS_MEMORY_FAILURE
591 bool "STA2X11 Companion Chip Support"
592 depends on X86_32_NON_STANDARD && PCI
593 select X86_DEV_DMA_OPS
597 select ARCH_REQUIRE_GPIOLIB
600 This adds support for boards based on the STA2X11 IO-Hub,
601 a.k.a. "ConneXt". The chip is used in place of the standard
602 PC chipset, so all "standard" peripherals are missing. If this
603 option is selected the kernel will still be able to boot on
604 standard PC machines.
607 tristate "Eurobraille/Iris poweroff module"
610 The Iris machines from EuroBraille do not have APM or ACPI support
611 to shut themselves down properly. A special I/O sequence is
612 needed to do so, which is what this module does at
615 This is only for Iris machines from EuroBraille.
619 config SCHED_OMIT_FRAME_POINTER
621 prompt "Single-depth WCHAN output"
624 Calculate simpler /proc/<PID>/wchan values. If this option
625 is disabled then wchan values will recurse back to the
626 caller function. This provides more accurate wchan values,
627 at the expense of slightly more scheduling overhead.
629 If in doubt, say "Y".
631 menuconfig HYPERVISOR_GUEST
632 bool "Linux guest support"
634 Say Y here to enable options for running Linux under various hyper-
635 visors. This option enables basic hypervisor detection and platform
638 If you say N, all options in this submenu will be skipped and
639 disabled, and Linux guest support won't be built in.
644 bool "Enable paravirtualization code"
646 This changes the kernel so it can modify itself when it is run
647 under a hypervisor, potentially improving performance significantly
648 over full virtualization. However, when run without a hypervisor
649 the kernel is theoretically slower and slightly larger.
651 config PARAVIRT_DEBUG
652 bool "paravirt-ops debugging"
653 depends on PARAVIRT && DEBUG_KERNEL
655 Enable to debug paravirt_ops internals. Specifically, BUG if
656 a paravirt_op is missing when it is called.
658 config PARAVIRT_SPINLOCKS
659 bool "Paravirtualization layer for spinlocks"
660 depends on PARAVIRT && SMP
661 select UNINLINE_SPIN_UNLOCK
663 Paravirtualized spinlocks allow a pvops backend to replace the
664 spinlock implementation with something virtualization-friendly
665 (for example, block the virtual CPU rather than spinning).
667 It has a minimal impact on native kernels and gives a nice performance
668 benefit on paravirtualized KVM / Xen kernels.
670 If you are unsure how to answer this question, answer Y.
672 source "arch/x86/xen/Kconfig"
675 bool "KVM Guest support (including kvmclock)"
677 select PARAVIRT_CLOCK
680 This option enables various optimizations for running under the KVM
681 hypervisor. It includes a paravirtualized clock, so that instead
682 of relying on a PIT (or probably other) emulation by the
683 underlying device model, the host provides the guest with
684 timing infrastructure such as time of day, and system time
687 bool "Enable debug information for KVM Guests in debugfs"
688 depends on KVM_GUEST && DEBUG_FS
691 This option enables collection of various statistics for KVM guest.
692 Statistics are displayed in debugfs filesystem. Enabling this option
693 may incur significant overhead.
695 source "arch/x86/lguest/Kconfig"
697 config PARAVIRT_TIME_ACCOUNTING
698 bool "Paravirtual steal time accounting"
702 Select this option to enable fine granularity task steal time
703 accounting. Time spent executing other tasks in parallel with
704 the current vCPU is discounted from the vCPU power. To account for
705 that, there can be a small performance impact.
707 If in doubt, say N here.
709 config PARAVIRT_CLOCK
712 endif #HYPERVISOR_GUEST
720 This option adds a kernel parameter 'memtest', which allows memtest
722 memtest=0, mean disabled; -- default
723 memtest=1, mean do 1 test pattern;
725 memtest=4, mean do 4 test patterns.
726 If you are unsure how to answer this question, answer N.
728 source "arch/x86/Kconfig.cpu"
732 prompt "HPET Timer Support" if X86_32
734 Use the IA-PC HPET (High Precision Event Timer) to manage
735 time in preference to the PIT and RTC, if a HPET is
737 HPET is the next generation timer replacing legacy 8254s.
738 The HPET provides a stable time base on SMP
739 systems, unlike the TSC, but it is more expensive to access,
740 as it is off-chip. You can find the HPET spec at
741 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
743 You can safely choose Y here. However, HPET will only be
744 activated if the platform and the BIOS support this feature.
745 Otherwise the 8254 will be used for timing services.
747 Choose N to continue using the legacy 8254 timer.
749 config HPET_EMULATE_RTC
751 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
754 def_bool y if X86_INTEL_MID
755 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
757 depends on X86_INTEL_MID && SFI
759 APB timer is the replacement for 8254, HPET on X86 MID platforms.
760 The APBT provides a stable time base on SMP
761 systems, unlike the TSC, but it is more expensive to access,
762 as it is off-chip. APB timers are always running regardless of CPU
763 C states, they are used as per CPU clockevent device when possible.
765 # Mark as expert because too many people got it wrong.
766 # The code disables itself when not needed.
769 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
770 bool "Enable DMI scanning" if EXPERT
772 Enabled scanning of DMI to identify machine quirks. Say Y
773 here unless you have verified that your setup is not
774 affected by entries in the DMI blacklist. Required by PNP
778 bool "Old AMD GART IOMMU support"
780 depends on X86_64 && PCI && AMD_NB
782 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
783 GART based hardware IOMMUs.
785 The GART supports full DMA access for devices with 32-bit access
786 limitations, on systems with more than 3 GB. This is usually needed
787 for USB, sound, many IDE/SATA chipsets and some other devices.
789 Newer systems typically have a modern AMD IOMMU, supported via
790 the CONFIG_AMD_IOMMU=y config option.
792 In normal configurations this driver is only active when needed:
793 there's more than 3 GB of memory and the system contains a
794 32-bit limited device.
799 bool "IBM Calgary IOMMU support"
801 depends on X86_64 && PCI
803 Support for hardware IOMMUs in IBM's xSeries x366 and x460
804 systems. Needed to run systems with more than 3GB of memory
805 properly with 32-bit PCI devices that do not support DAC
806 (Double Address Cycle). Calgary also supports bus level
807 isolation, where all DMAs pass through the IOMMU. This
808 prevents them from going anywhere except their intended
809 destination. This catches hard-to-find kernel bugs and
810 mis-behaving drivers and devices that do not use the DMA-API
811 properly to set up their DMA buffers. The IOMMU can be
812 turned off at boot time with the iommu=off parameter.
813 Normally the kernel will make the right choice by itself.
816 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
818 prompt "Should Calgary be enabled by default?"
819 depends on CALGARY_IOMMU
821 Should Calgary be enabled by default? if you choose 'y', Calgary
822 will be used (if it exists). If you choose 'n', Calgary will not be
823 used even if it exists. If you choose 'n' and would like to use
824 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
827 # need this always selected by IOMMU for the VIA workaround
831 Support for software bounce buffers used on x86-64 systems
832 which don't have a hardware IOMMU. Using this PCI devices
833 which can only access 32-bits of memory can be used on systems
834 with more than 3 GB of memory.
839 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
842 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
843 depends on X86_64 && SMP && DEBUG_KERNEL
844 select CPUMASK_OFFSTACK
846 Enable maximum number of CPUS and NUMA Nodes for this architecture.
850 int "Maximum number of CPUs" if SMP && !MAXSMP
851 range 2 8 if SMP && X86_32 && !X86_BIGSMP
852 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
853 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
855 default "8192" if MAXSMP
856 default "32" if SMP && X86_BIGSMP
859 This allows you to specify the maximum number of CPUs which this
860 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
861 supported value is 4096, otherwise the maximum value is 512. The
862 minimum value which makes sense is 2.
864 This is purely to save memory - each supported CPU adds
865 approximately eight kilobytes to the kernel image.
868 bool "SMT (Hyperthreading) scheduler support"
871 SMT scheduler support improves the CPU scheduler's decision making
872 when dealing with Intel Pentium 4 chips with HyperThreading at a
873 cost of slightly increased overhead in some places. If unsure say
878 prompt "Multi-core scheduler support"
881 Multi-core scheduler support improves the CPU scheduler's decision
882 making when dealing with multi-core CPU chips at a cost of slightly
883 increased overhead in some places. If unsure say N here.
885 source "kernel/Kconfig.preempt"
889 depends on !SMP && X86_LOCAL_APIC
892 bool "Local APIC support on uniprocessors" if !PCI_MSI
894 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
896 A local APIC (Advanced Programmable Interrupt Controller) is an
897 integrated interrupt controller in the CPU. If you have a single-CPU
898 system which has a processor with a local APIC, you can say Y here to
899 enable and use it. If you say Y here even though your machine doesn't
900 have a local APIC, then the kernel will still run with no slowdown at
901 all. The local APIC supports CPU-generated self-interrupts (timer,
902 performance counters), and the NMI watchdog which detects hard
906 bool "IO-APIC support on uniprocessors"
907 depends on X86_UP_APIC
909 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
910 SMP-capable replacement for PC-style interrupt controllers. Most
911 SMP systems and many recent uniprocessor systems have one.
913 If you have a single-CPU system with an IO-APIC, you can say Y here
914 to use it. If you say Y here even though your machine doesn't have
915 an IO-APIC, then the kernel will still run with no slowdown at all.
917 config X86_LOCAL_APIC
919 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
920 select GENERIC_IRQ_LEGACY_ALLOC_HWIRQ
924 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
927 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
928 bool "Reroute for broken boot IRQs"
929 depends on X86_IO_APIC
931 This option enables a workaround that fixes a source of
932 spurious interrupts. This is recommended when threaded
933 interrupt handling is used on systems where the generation of
934 superfluous "boot interrupts" cannot be disabled.
936 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
937 entry in the chipset's IO-APIC is masked (as, e.g. the RT
938 kernel does during interrupt handling). On chipsets where this
939 boot IRQ generation cannot be disabled, this workaround keeps
940 the original IRQ line masked so that only the equivalent "boot
941 IRQ" is delivered to the CPUs. The workaround also tells the
942 kernel to set up the IRQ handler on the boot IRQ line. In this
943 way only one interrupt is delivered to the kernel. Otherwise
944 the spurious second interrupt may cause the kernel to bring
945 down (vital) interrupt lines.
947 Only affects "broken" chipsets. Interrupt sharing may be
948 increased on these systems.
951 bool "Machine Check / overheating reporting"
954 Machine Check support allows the processor to notify the
955 kernel if it detects a problem (e.g. overheating, data corruption).
956 The action the kernel takes depends on the severity of the problem,
957 ranging from warning messages to halting the machine.
961 prompt "Intel MCE features"
962 depends on X86_MCE && X86_LOCAL_APIC
964 Additional support for intel specific MCE features such as
969 prompt "AMD MCE features"
970 depends on X86_MCE && X86_LOCAL_APIC
972 Additional support for AMD specific MCE features such as
973 the DRAM Error Threshold.
975 config X86_ANCIENT_MCE
976 bool "Support for old Pentium 5 / WinChip machine checks"
977 depends on X86_32 && X86_MCE
979 Include support for machine check handling on old Pentium 5 or WinChip
980 systems. These typically need to be enabled explicitly on the command
983 config X86_MCE_THRESHOLD
984 depends on X86_MCE_AMD || X86_MCE_INTEL
987 config X86_MCE_INJECT
989 tristate "Machine check injector support"
991 Provide support for injecting machine checks for testing purposes.
992 If you don't know what a machine check is and you don't do kernel
993 QA it is safe to say n.
995 config X86_THERMAL_VECTOR
997 depends on X86_MCE_INTEL
1000 bool "Enable VM86 support" if EXPERT
1004 This option is required by programs like DOSEMU to run
1005 16-bit real mode legacy code on x86 processors. It also may
1006 be needed by software like XFree86 to initialize some video
1007 cards via BIOS. Disabling this option saves about 6K.
1010 bool "Enable support for 16-bit segments" if EXPERT
1013 This option is required by programs like Wine to run 16-bit
1014 protected mode legacy code on x86 processors. Disabling
1015 this option saves about 300 bytes on i386, or around 6K text
1016 plus 16K runtime memory on x86-64,
1020 depends on X86_16BIT && X86_32
1024 depends on X86_16BIT && X86_64
1026 config X86_VSYSCALL_EMULATION
1027 bool "Enable vsyscall emulation" if EXPERT
1031 This enables emulation of the legacy vsyscall page. Disabling
1032 it is roughly equivalent to booting with vsyscall=none, except
1033 that it will also disable the helpful warning if a program
1034 tries to use a vsyscall. With this option set to N, offending
1035 programs will just segfault, citing addresses of the form
1038 This option is required by many programs built before 2013, and
1039 care should be used even with newer programs if set to N.
1041 Disabling this option saves about 7K of kernel size and
1042 possibly 4K of additional runtime pagetable memory.
1045 tristate "Toshiba Laptop support"
1048 This adds a driver to safely access the System Management Mode of
1049 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1050 not work on models with a Phoenix BIOS. The System Management Mode
1051 is used to set the BIOS and power saving options on Toshiba portables.
1053 For information on utilities to make use of this driver see the
1054 Toshiba Linux utilities web site at:
1055 <http://www.buzzard.org.uk/toshiba/>.
1057 Say Y if you intend to run this kernel on a Toshiba portable.
1061 tristate "Dell laptop support"
1064 This adds a driver to safely access the System Management Mode
1065 of the CPU on the Dell Inspiron 8000. The System Management Mode
1066 is used to read cpu temperature and cooling fan status and to
1067 control the fans on the I8K portables.
1069 This driver has been tested only on the Inspiron 8000 but it may
1070 also work with other Dell laptops. You can force loading on other
1071 models by passing the parameter `force=1' to the module. Use at
1074 For information on utilities to make use of this driver see the
1075 I8K Linux utilities web site at:
1076 <http://people.debian.org/~dz/i8k/>
1078 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
1081 config X86_REBOOTFIXUPS
1082 bool "Enable X86 board specific fixups for reboot"
1085 This enables chipset and/or board specific fixups to be done
1086 in order to get reboot to work correctly. This is only needed on
1087 some combinations of hardware and BIOS. The symptom, for which
1088 this config is intended, is when reboot ends with a stalled/hung
1091 Currently, the only fixup is for the Geode machines using
1092 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1094 Say Y if you want to enable the fixup. Currently, it's safe to
1095 enable this option even if you don't need it.
1099 tristate "CPU microcode loading support"
1100 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1104 If you say Y here, you will be able to update the microcode on
1105 certain Intel and AMD processors. The Intel support is for the
1106 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1107 Xeon etc. The AMD support is for families 0x10 and later. You will
1108 obviously need the actual microcode binary data itself which is not
1109 shipped with the Linux kernel.
1111 This option selects the general module only, you need to select
1112 at least one vendor specific module as well.
1114 To compile this driver as a module, choose M here: the module
1115 will be called microcode.
1117 config MICROCODE_INTEL
1118 bool "Intel microcode loading support"
1119 depends on MICROCODE
1123 This options enables microcode patch loading support for Intel
1126 For the current Intel microcode data package go to
1127 <https://downloadcenter.intel.com> and search for
1128 'Linux Processor Microcode Data File'.
1130 config MICROCODE_AMD
1131 bool "AMD microcode loading support"
1132 depends on MICROCODE
1135 If you select this option, microcode patch loading support for AMD
1136 processors will be enabled.
1138 config MICROCODE_OLD_INTERFACE
1140 depends on MICROCODE
1142 config MICROCODE_INTEL_EARLY
1145 config MICROCODE_AMD_EARLY
1148 config MICROCODE_EARLY
1149 bool "Early load microcode"
1150 depends on MICROCODE=y && BLK_DEV_INITRD
1151 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1152 select MICROCODE_AMD_EARLY if MICROCODE_AMD
1155 This option provides functionality to read additional microcode data
1156 at the beginning of initrd image. The data tells kernel to load
1157 microcode to CPU's as early as possible. No functional change if no
1158 microcode data is glued to the initrd, therefore it's safe to say Y.
1161 tristate "/dev/cpu/*/msr - Model-specific register support"
1163 This device gives privileged processes access to the x86
1164 Model-Specific Registers (MSRs). It is a character device with
1165 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1166 MSR accesses are directed to a specific CPU on multi-processor
1170 tristate "/dev/cpu/*/cpuid - CPU information support"
1172 This device gives processes access to the x86 CPUID instruction to
1173 be executed on a specific processor. It is a character device
1174 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1178 prompt "High Memory Support"
1185 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1186 However, the address space of 32-bit x86 processors is only 4
1187 Gigabytes large. That means that, if you have a large amount of
1188 physical memory, not all of it can be "permanently mapped" by the
1189 kernel. The physical memory that's not permanently mapped is called
1192 If you are compiling a kernel which will never run on a machine with
1193 more than 1 Gigabyte total physical RAM, answer "off" here (default
1194 choice and suitable for most users). This will result in a "3GB/1GB"
1195 split: 3GB are mapped so that each process sees a 3GB virtual memory
1196 space and the remaining part of the 4GB virtual memory space is used
1197 by the kernel to permanently map as much physical memory as
1200 If the machine has between 1 and 4 Gigabytes physical RAM, then
1203 If more than 4 Gigabytes is used then answer "64GB" here. This
1204 selection turns Intel PAE (Physical Address Extension) mode on.
1205 PAE implements 3-level paging on IA32 processors. PAE is fully
1206 supported by Linux, PAE mode is implemented on all recent Intel
1207 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1208 then the kernel will not boot on CPUs that don't support PAE!
1210 The actual amount of total physical memory will either be
1211 auto detected or can be forced by using a kernel command line option
1212 such as "mem=256M". (Try "man bootparam" or see the documentation of
1213 your boot loader (lilo or loadlin) about how to pass options to the
1214 kernel at boot time.)
1216 If unsure, say "off".
1221 Select this if you have a 32-bit processor and between 1 and 4
1222 gigabytes of physical RAM.
1229 Select this if you have a 32-bit processor and more than 4
1230 gigabytes of physical RAM.
1235 prompt "Memory split" if EXPERT
1239 Select the desired split between kernel and user memory.
1241 If the address range available to the kernel is less than the
1242 physical memory installed, the remaining memory will be available
1243 as "high memory". Accessing high memory is a little more costly
1244 than low memory, as it needs to be mapped into the kernel first.
1245 Note that increasing the kernel address space limits the range
1246 available to user programs, making the address space there
1247 tighter. Selecting anything other than the default 3G/1G split
1248 will also likely make your kernel incompatible with binary-only
1251 If you are not absolutely sure what you are doing, leave this
1255 bool "3G/1G user/kernel split"
1256 config VMSPLIT_3G_OPT
1258 bool "3G/1G user/kernel split (for full 1G low memory)"
1260 bool "2G/2G user/kernel split"
1261 config VMSPLIT_2G_OPT
1263 bool "2G/2G user/kernel split (for full 2G low memory)"
1265 bool "1G/3G user/kernel split"
1270 default 0xB0000000 if VMSPLIT_3G_OPT
1271 default 0x80000000 if VMSPLIT_2G
1272 default 0x78000000 if VMSPLIT_2G_OPT
1273 default 0x40000000 if VMSPLIT_1G
1279 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1282 bool "PAE (Physical Address Extension) Support"
1283 depends on X86_32 && !HIGHMEM4G
1285 PAE is required for NX support, and furthermore enables
1286 larger swapspace support for non-overcommit purposes. It
1287 has the cost of more pagetable lookup overhead, and also
1288 consumes more pagetable space per process.
1290 config ARCH_PHYS_ADDR_T_64BIT
1292 depends on X86_64 || X86_PAE
1294 config ARCH_DMA_ADDR_T_64BIT
1296 depends on X86_64 || HIGHMEM64G
1298 config X86_DIRECT_GBPAGES
1300 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1302 Certain kernel features effectively disable kernel
1303 linear 1 GB mappings (even if the CPU otherwise
1304 supports them), so don't confuse the user by printing
1305 that we have them enabled.
1307 # Common NUMA Features
1309 bool "Numa Memory Allocation and Scheduler Support"
1311 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1312 default y if X86_BIGSMP
1314 Enable NUMA (Non Uniform Memory Access) support.
1316 The kernel will try to allocate memory used by a CPU on the
1317 local memory controller of the CPU and add some more
1318 NUMA awareness to the kernel.
1320 For 64-bit this is recommended if the system is Intel Core i7
1321 (or later), AMD Opteron, or EM64T NUMA.
1323 For 32-bit this is only needed if you boot a 32-bit
1324 kernel on a 64-bit NUMA platform.
1326 Otherwise, you should say N.
1330 prompt "Old style AMD Opteron NUMA detection"
1331 depends on X86_64 && NUMA && PCI
1333 Enable AMD NUMA node topology detection. You should say Y here if
1334 you have a multi processor AMD system. This uses an old method to
1335 read the NUMA configuration directly from the builtin Northbridge
1336 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1337 which also takes priority if both are compiled in.
1339 config X86_64_ACPI_NUMA
1341 prompt "ACPI NUMA detection"
1342 depends on X86_64 && NUMA && ACPI && PCI
1345 Enable ACPI SRAT based node topology detection.
1347 # Some NUMA nodes have memory ranges that span
1348 # other nodes. Even though a pfn is valid and
1349 # between a node's start and end pfns, it may not
1350 # reside on that node. See memmap_init_zone()
1352 config NODES_SPAN_OTHER_NODES
1354 depends on X86_64_ACPI_NUMA
1357 bool "NUMA emulation"
1360 Enable NUMA emulation. A flat machine will be split
1361 into virtual nodes when booted with "numa=fake=N", where N is the
1362 number of nodes. This is only useful for debugging.
1365 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1367 default "10" if MAXSMP
1368 default "6" if X86_64
1370 depends on NEED_MULTIPLE_NODES
1372 Specify the maximum number of NUMA Nodes available on the target
1373 system. Increases memory reserved to accommodate various tables.
1375 config ARCH_HAVE_MEMORY_PRESENT
1377 depends on X86_32 && DISCONTIGMEM
1379 config NEED_NODE_MEMMAP_SIZE
1381 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1383 config ARCH_FLATMEM_ENABLE
1385 depends on X86_32 && !NUMA
1387 config ARCH_DISCONTIGMEM_ENABLE
1389 depends on NUMA && X86_32
1391 config ARCH_DISCONTIGMEM_DEFAULT
1393 depends on NUMA && X86_32
1395 config ARCH_SPARSEMEM_ENABLE
1397 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1398 select SPARSEMEM_STATIC if X86_32
1399 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1401 config ARCH_SPARSEMEM_DEFAULT
1405 config ARCH_SELECT_MEMORY_MODEL
1407 depends on ARCH_SPARSEMEM_ENABLE
1409 config ARCH_MEMORY_PROBE
1410 bool "Enable sysfs memory/probe interface"
1411 depends on X86_64 && MEMORY_HOTPLUG
1413 This option enables a sysfs memory/probe interface for testing.
1414 See Documentation/memory-hotplug.txt for more information.
1415 If you are unsure how to answer this question, answer N.
1417 config ARCH_PROC_KCORE_TEXT
1419 depends on X86_64 && PROC_KCORE
1421 config ILLEGAL_POINTER_VALUE
1424 default 0xdead000000000000 if X86_64
1429 bool "Allocate 3rd-level pagetables from highmem"
1432 The VM uses one page table entry for each page of physical memory.
1433 For systems with a lot of RAM, this can be wasteful of precious
1434 low memory. Setting this option will put user-space page table
1435 entries in high memory.
1437 config X86_CHECK_BIOS_CORRUPTION
1438 bool "Check for low memory corruption"
1440 Periodically check for memory corruption in low memory, which
1441 is suspected to be caused by BIOS. Even when enabled in the
1442 configuration, it is disabled at runtime. Enable it by
1443 setting "memory_corruption_check=1" on the kernel command
1444 line. By default it scans the low 64k of memory every 60
1445 seconds; see the memory_corruption_check_size and
1446 memory_corruption_check_period parameters in
1447 Documentation/kernel-parameters.txt to adjust this.
1449 When enabled with the default parameters, this option has
1450 almost no overhead, as it reserves a relatively small amount
1451 of memory and scans it infrequently. It both detects corruption
1452 and prevents it from affecting the running system.
1454 It is, however, intended as a diagnostic tool; if repeatable
1455 BIOS-originated corruption always affects the same memory,
1456 you can use memmap= to prevent the kernel from using that
1459 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1460 bool "Set the default setting of memory_corruption_check"
1461 depends on X86_CHECK_BIOS_CORRUPTION
1464 Set whether the default state of memory_corruption_check is
1467 config X86_RESERVE_LOW
1468 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1472 Specify the amount of low memory to reserve for the BIOS.
1474 The first page contains BIOS data structures that the kernel
1475 must not use, so that page must always be reserved.
1477 By default we reserve the first 64K of physical RAM, as a
1478 number of BIOSes are known to corrupt that memory range
1479 during events such as suspend/resume or monitor cable
1480 insertion, so it must not be used by the kernel.
1482 You can set this to 4 if you are absolutely sure that you
1483 trust the BIOS to get all its memory reservations and usages
1484 right. If you know your BIOS have problems beyond the
1485 default 64K area, you can set this to 640 to avoid using the
1486 entire low memory range.
1488 If you have doubts about the BIOS (e.g. suspend/resume does
1489 not work or there's kernel crashes after certain hardware
1490 hotplug events) then you might want to enable
1491 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1492 typical corruption patterns.
1494 Leave this to the default value of 64 if you are unsure.
1496 config MATH_EMULATION
1498 prompt "Math emulation" if X86_32
1500 Linux can emulate a math coprocessor (used for floating point
1501 operations) if you don't have one. 486DX and Pentium processors have
1502 a math coprocessor built in, 486SX and 386 do not, unless you added
1503 a 487DX or 387, respectively. (The messages during boot time can
1504 give you some hints here ["man dmesg"].) Everyone needs either a
1505 coprocessor or this emulation.
1507 If you don't have a math coprocessor, you need to say Y here; if you
1508 say Y here even though you have a coprocessor, the coprocessor will
1509 be used nevertheless. (This behavior can be changed with the kernel
1510 command line option "no387", which comes handy if your coprocessor
1511 is broken. Try "man bootparam" or see the documentation of your boot
1512 loader (lilo or loadlin) about how to pass options to the kernel at
1513 boot time.) This means that it is a good idea to say Y here if you
1514 intend to use this kernel on different machines.
1516 More information about the internals of the Linux math coprocessor
1517 emulation can be found in <file:arch/x86/math-emu/README>.
1519 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1520 kernel, it won't hurt.
1524 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1526 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1527 the Memory Type Range Registers (MTRRs) may be used to control
1528 processor access to memory ranges. This is most useful if you have
1529 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1530 allows bus write transfers to be combined into a larger transfer
1531 before bursting over the PCI/AGP bus. This can increase performance
1532 of image write operations 2.5 times or more. Saying Y here creates a
1533 /proc/mtrr file which may be used to manipulate your processor's
1534 MTRRs. Typically the X server should use this.
1536 This code has a reasonably generic interface so that similar
1537 control registers on other processors can be easily supported
1540 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1541 Registers (ARRs) which provide a similar functionality to MTRRs. For
1542 these, the ARRs are used to emulate the MTRRs.
1543 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1544 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1545 write-combining. All of these processors are supported by this code
1546 and it makes sense to say Y here if you have one of them.
1548 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1549 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1550 can lead to all sorts of problems, so it's good to say Y here.
1552 You can safely say Y even if your machine doesn't have MTRRs, you'll
1553 just add about 9 KB to your kernel.
1555 See <file:Documentation/x86/mtrr.txt> for more information.
1557 config MTRR_SANITIZER
1559 prompt "MTRR cleanup support"
1562 Convert MTRR layout from continuous to discrete, so X drivers can
1563 add writeback entries.
1565 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1566 The largest mtrr entry size for a continuous block can be set with
1571 config MTRR_SANITIZER_ENABLE_DEFAULT
1572 int "MTRR cleanup enable value (0-1)"
1575 depends on MTRR_SANITIZER
1577 Enable mtrr cleanup default value
1579 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1580 int "MTRR cleanup spare reg num (0-7)"
1583 depends on MTRR_SANITIZER
1585 mtrr cleanup spare entries default, it can be changed via
1586 mtrr_spare_reg_nr=N on the kernel command line.
1590 prompt "x86 PAT support" if EXPERT
1593 Use PAT attributes to setup page level cache control.
1595 PATs are the modern equivalents of MTRRs and are much more
1596 flexible than MTRRs.
1598 Say N here if you see bootup problems (boot crash, boot hang,
1599 spontaneous reboots) or a non-working video driver.
1603 config ARCH_USES_PG_UNCACHED
1609 prompt "x86 architectural random number generator" if EXPERT
1611 Enable the x86 architectural RDRAND instruction
1612 (Intel Bull Mountain technology) to generate random numbers.
1613 If supported, this is a high bandwidth, cryptographically
1614 secure hardware random number generator.
1618 prompt "Supervisor Mode Access Prevention" if EXPERT
1620 Supervisor Mode Access Prevention (SMAP) is a security
1621 feature in newer Intel processors. There is a small
1622 performance cost if this enabled and turned on; there is
1623 also a small increase in the kernel size if this is enabled.
1627 config X86_INTEL_MPX
1628 prompt "Intel MPX (Memory Protection Extensions)"
1630 depends on CPU_SUP_INTEL
1632 MPX provides hardware features that can be used in
1633 conjunction with compiler-instrumented code to check
1634 memory references. It is designed to detect buffer
1635 overflow or underflow bugs.
1637 This option enables running applications which are
1638 instrumented or otherwise use MPX. It does not use MPX
1639 itself inside the kernel or to protect the kernel
1640 against bad memory references.
1642 Enabling this option will make the kernel larger:
1643 ~8k of kernel text and 36 bytes of data on a 64-bit
1644 defconfig. It adds a long to the 'mm_struct' which
1645 will increase the kernel memory overhead of each
1646 process and adds some branches to paths used during
1647 exec() and munmap().
1649 For details, see Documentation/x86/intel_mpx.txt
1654 bool "EFI runtime service support"
1657 select EFI_RUNTIME_WRAPPERS
1659 This enables the kernel to use EFI runtime services that are
1660 available (such as the EFI variable services).
1662 This option is only useful on systems that have EFI firmware.
1663 In addition, you should use the latest ELILO loader available
1664 at <http://elilo.sourceforge.net> in order to take advantage
1665 of EFI runtime services. However, even with this option, the
1666 resultant kernel should continue to boot on existing non-EFI
1670 bool "EFI stub support"
1671 depends on EFI && !X86_USE_3DNOW
1674 This kernel feature allows a bzImage to be loaded directly
1675 by EFI firmware without the use of a bootloader.
1677 See Documentation/efi-stub.txt for more information.
1680 bool "EFI mixed-mode support"
1681 depends on EFI_STUB && X86_64
1683 Enabling this feature allows a 64-bit kernel to be booted
1684 on a 32-bit firmware, provided that your CPU supports 64-bit
1687 Note that it is not possible to boot a mixed-mode enabled
1688 kernel via the EFI boot stub - a bootloader that supports
1689 the EFI handover protocol must be used.
1695 prompt "Enable seccomp to safely compute untrusted bytecode"
1697 This kernel feature is useful for number crunching applications
1698 that may need to compute untrusted bytecode during their
1699 execution. By using pipes or other transports made available to
1700 the process as file descriptors supporting the read/write
1701 syscalls, it's possible to isolate those applications in
1702 their own address space using seccomp. Once seccomp is
1703 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1704 and the task is only allowed to execute a few safe syscalls
1705 defined by each seccomp mode.
1707 If unsure, say Y. Only embedded should say N here.
1709 source kernel/Kconfig.hz
1712 bool "kexec system call"
1714 kexec is a system call that implements the ability to shutdown your
1715 current kernel, and to start another kernel. It is like a reboot
1716 but it is independent of the system firmware. And like a reboot
1717 you can start any kernel with it, not just Linux.
1719 The name comes from the similarity to the exec system call.
1721 It is an ongoing process to be certain the hardware in a machine
1722 is properly shutdown, so do not be surprised if this code does not
1723 initially work for you. As of this writing the exact hardware
1724 interface is strongly in flux, so no good recommendation can be
1728 bool "kexec file based system call"
1733 depends on CRYPTO_SHA256=y
1735 This is new version of kexec system call. This system call is
1736 file based and takes file descriptors as system call argument
1737 for kernel and initramfs as opposed to list of segments as
1738 accepted by previous system call.
1740 config KEXEC_VERIFY_SIG
1741 bool "Verify kernel signature during kexec_file_load() syscall"
1742 depends on KEXEC_FILE
1744 This option makes kernel signature verification mandatory for
1745 the kexec_file_load() syscall.
1747 In addition to that option, you need to enable signature
1748 verification for the corresponding kernel image type being
1749 loaded in order for this to work.
1751 config KEXEC_BZIMAGE_VERIFY_SIG
1752 bool "Enable bzImage signature verification support"
1753 depends on KEXEC_VERIFY_SIG
1754 depends on SIGNED_PE_FILE_VERIFICATION
1755 select SYSTEM_TRUSTED_KEYRING
1757 Enable bzImage signature verification support.
1760 bool "kernel crash dumps"
1761 depends on X86_64 || (X86_32 && HIGHMEM)
1763 Generate crash dump after being started by kexec.
1764 This should be normally only set in special crash dump kernels
1765 which are loaded in the main kernel with kexec-tools into
1766 a specially reserved region and then later executed after
1767 a crash by kdump/kexec. The crash dump kernel must be compiled
1768 to a memory address not used by the main kernel or BIOS using
1769 PHYSICAL_START, or it must be built as a relocatable image
1770 (CONFIG_RELOCATABLE=y).
1771 For more details see Documentation/kdump/kdump.txt
1775 depends on KEXEC && HIBERNATION
1777 Jump between original kernel and kexeced kernel and invoke
1778 code in physical address mode via KEXEC
1780 config PHYSICAL_START
1781 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1784 This gives the physical address where the kernel is loaded.
1786 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1787 bzImage will decompress itself to above physical address and
1788 run from there. Otherwise, bzImage will run from the address where
1789 it has been loaded by the boot loader and will ignore above physical
1792 In normal kdump cases one does not have to set/change this option
1793 as now bzImage can be compiled as a completely relocatable image
1794 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1795 address. This option is mainly useful for the folks who don't want
1796 to use a bzImage for capturing the crash dump and want to use a
1797 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1798 to be specifically compiled to run from a specific memory area
1799 (normally a reserved region) and this option comes handy.
1801 So if you are using bzImage for capturing the crash dump,
1802 leave the value here unchanged to 0x1000000 and set
1803 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1804 for capturing the crash dump change this value to start of
1805 the reserved region. In other words, it can be set based on
1806 the "X" value as specified in the "crashkernel=YM@XM"
1807 command line boot parameter passed to the panic-ed
1808 kernel. Please take a look at Documentation/kdump/kdump.txt
1809 for more details about crash dumps.
1811 Usage of bzImage for capturing the crash dump is recommended as
1812 one does not have to build two kernels. Same kernel can be used
1813 as production kernel and capture kernel. Above option should have
1814 gone away after relocatable bzImage support is introduced. But it
1815 is present because there are users out there who continue to use
1816 vmlinux for dump capture. This option should go away down the
1819 Don't change this unless you know what you are doing.
1822 bool "Build a relocatable kernel"
1825 This builds a kernel image that retains relocation information
1826 so it can be loaded someplace besides the default 1MB.
1827 The relocations tend to make the kernel binary about 10% larger,
1828 but are discarded at runtime.
1830 One use is for the kexec on panic case where the recovery kernel
1831 must live at a different physical address than the primary
1834 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1835 it has been loaded at and the compile time physical address
1836 (CONFIG_PHYSICAL_START) is used as the minimum location.
1838 config RANDOMIZE_BASE
1839 bool "Randomize the address of the kernel image"
1840 depends on RELOCATABLE
1843 Randomizes the physical and virtual address at which the
1844 kernel image is decompressed, as a security feature that
1845 deters exploit attempts relying on knowledge of the location
1846 of kernel internals.
1848 Entropy is generated using the RDRAND instruction if it is
1849 supported. If RDTSC is supported, it is used as well. If
1850 neither RDRAND nor RDTSC are supported, then randomness is
1851 read from the i8254 timer.
1853 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1854 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1855 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1856 minimum of 2MiB, only 10 bits of entropy is theoretically
1857 possible. At best, due to page table layouts, 64-bit can use
1858 9 bits of entropy and 32-bit uses 8 bits.
1862 config RANDOMIZE_BASE_MAX_OFFSET
1863 hex "Maximum kASLR offset allowed" if EXPERT
1864 depends on RANDOMIZE_BASE
1865 range 0x0 0x20000000 if X86_32
1866 default "0x20000000" if X86_32
1867 range 0x0 0x40000000 if X86_64
1868 default "0x40000000" if X86_64
1870 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1871 memory is used to determine the maximal offset in bytes that will
1872 be applied to the kernel when kernel Address Space Layout
1873 Randomization (kASLR) is active. This must be a multiple of
1876 On 32-bit this is limited to 512MiB by page table layouts. The
1879 On 64-bit this is limited by how the kernel fixmap page table is
1880 positioned, so this cannot be larger than 1GiB currently. Without
1881 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1882 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1883 modules area will shrink to compensate, up to the current maximum
1884 1GiB to 1GiB split. The default is 1GiB.
1886 If unsure, leave at the default value.
1888 # Relocation on x86 needs some additional build support
1889 config X86_NEED_RELOCS
1891 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1893 config PHYSICAL_ALIGN
1894 hex "Alignment value to which kernel should be aligned"
1896 range 0x2000 0x1000000 if X86_32
1897 range 0x200000 0x1000000 if X86_64
1899 This value puts the alignment restrictions on physical address
1900 where kernel is loaded and run from. Kernel is compiled for an
1901 address which meets above alignment restriction.
1903 If bootloader loads the kernel at a non-aligned address and
1904 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1905 address aligned to above value and run from there.
1907 If bootloader loads the kernel at a non-aligned address and
1908 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1909 load address and decompress itself to the address it has been
1910 compiled for and run from there. The address for which kernel is
1911 compiled already meets above alignment restrictions. Hence the
1912 end result is that kernel runs from a physical address meeting
1913 above alignment restrictions.
1915 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1916 this value must be a multiple of 0x200000.
1918 Don't change this unless you know what you are doing.
1921 bool "Support for hot-pluggable CPUs"
1924 Say Y here to allow turning CPUs off and on. CPUs can be
1925 controlled through /sys/devices/system/cpu.
1926 ( Note: power management support will enable this option
1927 automatically on SMP systems. )
1928 Say N if you want to disable CPU hotplug.
1930 config BOOTPARAM_HOTPLUG_CPU0
1931 bool "Set default setting of cpu0_hotpluggable"
1933 depends on HOTPLUG_CPU
1935 Set whether default state of cpu0_hotpluggable is on or off.
1937 Say Y here to enable CPU0 hotplug by default. If this switch
1938 is turned on, there is no need to give cpu0_hotplug kernel
1939 parameter and the CPU0 hotplug feature is enabled by default.
1941 Please note: there are two known CPU0 dependencies if you want
1942 to enable the CPU0 hotplug feature either by this switch or by
1943 cpu0_hotplug kernel parameter.
1945 First, resume from hibernate or suspend always starts from CPU0.
1946 So hibernate and suspend are prevented if CPU0 is offline.
1948 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1949 offline if any interrupt can not migrate out of CPU0. There may
1950 be other CPU0 dependencies.
1952 Please make sure the dependencies are under your control before
1953 you enable this feature.
1955 Say N if you don't want to enable CPU0 hotplug feature by default.
1956 You still can enable the CPU0 hotplug feature at boot by kernel
1957 parameter cpu0_hotplug.
1959 config DEBUG_HOTPLUG_CPU0
1961 prompt "Debug CPU0 hotplug"
1962 depends on HOTPLUG_CPU
1964 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1965 soon as possible and boots up userspace with CPU0 offlined. User
1966 can online CPU0 back after boot time.
1968 To debug CPU0 hotplug, you need to enable CPU0 offline/online
1969 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
1970 compilation or giving cpu0_hotplug kernel parameter at boot.
1976 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
1977 depends on X86_32 || IA32_EMULATION
1979 Certain buggy versions of glibc will crash if they are
1980 presented with a 32-bit vDSO that is not mapped at the address
1981 indicated in its segment table.
1983 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
1984 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
1985 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
1986 the only released version with the bug, but OpenSUSE 9
1987 contains a buggy "glibc 2.3.2".
1989 The symptom of the bug is that everything crashes on startup, saying:
1990 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
1992 Saying Y here changes the default value of the vdso32 boot
1993 option from 1 to 0, which turns off the 32-bit vDSO entirely.
1994 This works around the glibc bug but hurts performance.
1996 If unsure, say N: if you are compiling your own kernel, you
1997 are unlikely to be using a buggy version of glibc.
2000 bool "Built-in kernel command line"
2002 Allow for specifying boot arguments to the kernel at
2003 build time. On some systems (e.g. embedded ones), it is
2004 necessary or convenient to provide some or all of the
2005 kernel boot arguments with the kernel itself (that is,
2006 to not rely on the boot loader to provide them.)
2008 To compile command line arguments into the kernel,
2009 set this option to 'Y', then fill in the
2010 the boot arguments in CONFIG_CMDLINE.
2012 Systems with fully functional boot loaders (i.e. non-embedded)
2013 should leave this option set to 'N'.
2016 string "Built-in kernel command string"
2017 depends on CMDLINE_BOOL
2020 Enter arguments here that should be compiled into the kernel
2021 image and used at boot time. If the boot loader provides a
2022 command line at boot time, it is appended to this string to
2023 form the full kernel command line, when the system boots.
2025 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2026 change this behavior.
2028 In most cases, the command line (whether built-in or provided
2029 by the boot loader) should specify the device for the root
2032 config CMDLINE_OVERRIDE
2033 bool "Built-in command line overrides boot loader arguments"
2034 depends on CMDLINE_BOOL
2036 Set this option to 'Y' to have the kernel ignore the boot loader
2037 command line, and use ONLY the built-in command line.
2039 This is used to work around broken boot loaders. This should
2040 be set to 'N' under normal conditions.
2042 source "kernel/livepatch/Kconfig"
2046 config ARCH_ENABLE_MEMORY_HOTPLUG
2048 depends on X86_64 || (X86_32 && HIGHMEM)
2050 config ARCH_ENABLE_MEMORY_HOTREMOVE
2052 depends on MEMORY_HOTPLUG
2054 config USE_PERCPU_NUMA_NODE_ID
2058 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2060 depends on X86_64 || X86_PAE
2062 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2064 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2066 menu "Power management and ACPI options"
2068 config ARCH_HIBERNATION_HEADER
2070 depends on X86_64 && HIBERNATION
2072 source "kernel/power/Kconfig"
2074 source "drivers/acpi/Kconfig"
2076 source "drivers/sfi/Kconfig"
2083 tristate "APM (Advanced Power Management) BIOS support"
2084 depends on X86_32 && PM_SLEEP
2086 APM is a BIOS specification for saving power using several different
2087 techniques. This is mostly useful for battery powered laptops with
2088 APM compliant BIOSes. If you say Y here, the system time will be
2089 reset after a RESUME operation, the /proc/apm device will provide
2090 battery status information, and user-space programs will receive
2091 notification of APM "events" (e.g. battery status change).
2093 If you select "Y" here, you can disable actual use of the APM
2094 BIOS by passing the "apm=off" option to the kernel at boot time.
2096 Note that the APM support is almost completely disabled for
2097 machines with more than one CPU.
2099 In order to use APM, you will need supporting software. For location
2100 and more information, read <file:Documentation/power/apm-acpi.txt>
2101 and the Battery Powered Linux mini-HOWTO, available from
2102 <http://www.tldp.org/docs.html#howto>.
2104 This driver does not spin down disk drives (see the hdparm(8)
2105 manpage ("man 8 hdparm") for that), and it doesn't turn off
2106 VESA-compliant "green" monitors.
2108 This driver does not support the TI 4000M TravelMate and the ACER
2109 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2110 desktop machines also don't have compliant BIOSes, and this driver
2111 may cause those machines to panic during the boot phase.
2113 Generally, if you don't have a battery in your machine, there isn't
2114 much point in using this driver and you should say N. If you get
2115 random kernel OOPSes or reboots that don't seem to be related to
2116 anything, try disabling/enabling this option (or disabling/enabling
2119 Some other things you should try when experiencing seemingly random,
2122 1) make sure that you have enough swap space and that it is
2124 2) pass the "no-hlt" option to the kernel
2125 3) switch on floating point emulation in the kernel and pass
2126 the "no387" option to the kernel
2127 4) pass the "floppy=nodma" option to the kernel
2128 5) pass the "mem=4M" option to the kernel (thereby disabling
2129 all but the first 4 MB of RAM)
2130 6) make sure that the CPU is not over clocked.
2131 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2132 8) disable the cache from your BIOS settings
2133 9) install a fan for the video card or exchange video RAM
2134 10) install a better fan for the CPU
2135 11) exchange RAM chips
2136 12) exchange the motherboard.
2138 To compile this driver as a module, choose M here: the
2139 module will be called apm.
2143 config APM_IGNORE_USER_SUSPEND
2144 bool "Ignore USER SUSPEND"
2146 This option will ignore USER SUSPEND requests. On machines with a
2147 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2148 series notebooks, it is necessary to say Y because of a BIOS bug.
2150 config APM_DO_ENABLE
2151 bool "Enable PM at boot time"
2153 Enable APM features at boot time. From page 36 of the APM BIOS
2154 specification: "When disabled, the APM BIOS does not automatically
2155 power manage devices, enter the Standby State, enter the Suspend
2156 State, or take power saving steps in response to CPU Idle calls."
2157 This driver will make CPU Idle calls when Linux is idle (unless this
2158 feature is turned off -- see "Do CPU IDLE calls", below). This
2159 should always save battery power, but more complicated APM features
2160 will be dependent on your BIOS implementation. You may need to turn
2161 this option off if your computer hangs at boot time when using APM
2162 support, or if it beeps continuously instead of suspending. Turn
2163 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2164 T400CDT. This is off by default since most machines do fine without
2169 bool "Make CPU Idle calls when idle"
2171 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2172 On some machines, this can activate improved power savings, such as
2173 a slowed CPU clock rate, when the machine is idle. These idle calls
2174 are made after the idle loop has run for some length of time (e.g.,
2175 333 mS). On some machines, this will cause a hang at boot time or
2176 whenever the CPU becomes idle. (On machines with more than one CPU,
2177 this option does nothing.)
2179 config APM_DISPLAY_BLANK
2180 bool "Enable console blanking using APM"
2182 Enable console blanking using the APM. Some laptops can use this to
2183 turn off the LCD backlight when the screen blanker of the Linux
2184 virtual console blanks the screen. Note that this is only used by
2185 the virtual console screen blanker, and won't turn off the backlight
2186 when using the X Window system. This also doesn't have anything to
2187 do with your VESA-compliant power-saving monitor. Further, this
2188 option doesn't work for all laptops -- it might not turn off your
2189 backlight at all, or it might print a lot of errors to the console,
2190 especially if you are using gpm.
2192 config APM_ALLOW_INTS
2193 bool "Allow interrupts during APM BIOS calls"
2195 Normally we disable external interrupts while we are making calls to
2196 the APM BIOS as a measure to lessen the effects of a badly behaving
2197 BIOS implementation. The BIOS should reenable interrupts if it
2198 needs to. Unfortunately, some BIOSes do not -- especially those in
2199 many of the newer IBM Thinkpads. If you experience hangs when you
2200 suspend, try setting this to Y. Otherwise, say N.
2204 source "drivers/cpufreq/Kconfig"
2206 source "drivers/cpuidle/Kconfig"
2208 source "drivers/idle/Kconfig"
2213 menu "Bus options (PCI etc.)"
2219 Find out whether you have a PCI motherboard. PCI is the name of a
2220 bus system, i.e. the way the CPU talks to the other stuff inside
2221 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2222 VESA. If you have PCI, say Y, otherwise N.
2225 prompt "PCI access mode"
2226 depends on X86_32 && PCI
2229 On PCI systems, the BIOS can be used to detect the PCI devices and
2230 determine their configuration. However, some old PCI motherboards
2231 have BIOS bugs and may crash if this is done. Also, some embedded
2232 PCI-based systems don't have any BIOS at all. Linux can also try to
2233 detect the PCI hardware directly without using the BIOS.
2235 With this option, you can specify how Linux should detect the
2236 PCI devices. If you choose "BIOS", the BIOS will be used,
2237 if you choose "Direct", the BIOS won't be used, and if you
2238 choose "MMConfig", then PCI Express MMCONFIG will be used.
2239 If you choose "Any", the kernel will try MMCONFIG, then the
2240 direct access method and falls back to the BIOS if that doesn't
2241 work. If unsure, go with the default, which is "Any".
2246 config PCI_GOMMCONFIG
2263 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2265 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2268 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2272 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2276 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2280 depends on PCI && XEN
2288 bool "Support mmconfig PCI config space access"
2289 depends on X86_64 && PCI && ACPI
2291 config PCI_CNB20LE_QUIRK
2292 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2295 Read the PCI windows out of the CNB20LE host bridge. This allows
2296 PCI hotplug to work on systems with the CNB20LE chipset which do
2299 There's no public spec for this chipset, and this functionality
2300 is known to be incomplete.
2302 You should say N unless you know you need this.
2304 source "drivers/pci/pcie/Kconfig"
2306 source "drivers/pci/Kconfig"
2308 # x86_64 have no ISA slots, but can have ISA-style DMA.
2310 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2313 Enables ISA-style DMA support for devices requiring such controllers.
2321 Find out whether you have ISA slots on your motherboard. ISA is the
2322 name of a bus system, i.e. the way the CPU talks to the other stuff
2323 inside your box. Other bus systems are PCI, EISA, MicroChannel
2324 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2325 newer boards don't support it. If you have ISA, say Y, otherwise N.
2331 The Extended Industry Standard Architecture (EISA) bus was
2332 developed as an open alternative to the IBM MicroChannel bus.
2334 The EISA bus provided some of the features of the IBM MicroChannel
2335 bus while maintaining backward compatibility with cards made for
2336 the older ISA bus. The EISA bus saw limited use between 1988 and
2337 1995 when it was made obsolete by the PCI bus.
2339 Say Y here if you are building a kernel for an EISA-based machine.
2343 source "drivers/eisa/Kconfig"
2346 tristate "NatSemi SCx200 support"
2348 This provides basic support for National Semiconductor's
2349 (now AMD's) Geode processors. The driver probes for the
2350 PCI-IDs of several on-chip devices, so its a good dependency
2351 for other scx200_* drivers.
2353 If compiled as a module, the driver is named scx200.
2355 config SCx200HR_TIMER
2356 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2360 This driver provides a clocksource built upon the on-chip
2361 27MHz high-resolution timer. Its also a workaround for
2362 NSC Geode SC-1100's buggy TSC, which loses time when the
2363 processor goes idle (as is done by the scheduler). The
2364 other workaround is idle=poll boot option.
2367 bool "One Laptop Per Child support"
2374 Add support for detecting the unique features of the OLPC
2378 bool "OLPC XO-1 Power Management"
2379 depends on OLPC && MFD_CS5535 && PM_SLEEP
2382 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2385 bool "OLPC XO-1 Real Time Clock"
2386 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2388 Add support for the XO-1 real time clock, which can be used as a
2389 programmable wakeup source.
2392 bool "OLPC XO-1 SCI extras"
2393 depends on OLPC && OLPC_XO1_PM
2399 Add support for SCI-based features of the OLPC XO-1 laptop:
2400 - EC-driven system wakeups
2404 - AC adapter status updates
2405 - Battery status updates
2407 config OLPC_XO15_SCI
2408 bool "OLPC XO-1.5 SCI extras"
2409 depends on OLPC && ACPI
2412 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2413 - EC-driven system wakeups
2414 - AC adapter status updates
2415 - Battery status updates
2418 bool "PCEngines ALIX System Support (LED setup)"
2421 This option enables system support for the PCEngines ALIX.
2422 At present this just sets up LEDs for GPIO control on
2423 ALIX2/3/6 boards. However, other system specific setup should
2426 Note: You must still enable the drivers for GPIO and LED support
2427 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2429 Note: You have to set alix.force=1 for boards with Award BIOS.
2432 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2435 This option enables system support for the Soekris Engineering net5501.
2438 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2442 This option enables system support for the Traverse Technologies GEOS.
2445 bool "Technologic Systems TS-5500 platform support"
2447 select CHECK_SIGNATURE
2451 This option enables system support for the Technologic Systems TS-5500.
2457 depends on CPU_SUP_AMD && PCI
2459 source "drivers/pcmcia/Kconfig"
2461 source "drivers/pci/hotplug/Kconfig"
2464 tristate "RapidIO support"
2468 If enabled this option will include drivers and the core
2469 infrastructure code to support RapidIO interconnect devices.
2471 source "drivers/rapidio/Kconfig"
2474 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2476 Firmwares often provide initial graphics framebuffers so the BIOS,
2477 bootloader or kernel can show basic video-output during boot for
2478 user-guidance and debugging. Historically, x86 used the VESA BIOS
2479 Extensions and EFI-framebuffers for this, which are mostly limited
2481 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2482 framebuffers so the new generic system-framebuffer drivers can be
2483 used on x86. If the framebuffer is not compatible with the generic
2484 modes, it is adverticed as fallback platform framebuffer so legacy
2485 drivers like efifb, vesafb and uvesafb can pick it up.
2486 If this option is not selected, all system framebuffers are always
2487 marked as fallback platform framebuffers as usual.
2489 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2490 not be able to pick up generic system framebuffers if this option
2491 is selected. You are highly encouraged to enable simplefb as
2492 replacement if you select this option. simplefb can correctly deal
2493 with generic system framebuffers. But you should still keep vesafb
2494 and others enabled as fallback if a system framebuffer is
2495 incompatible with simplefb.
2502 menu "Executable file formats / Emulations"
2504 source "fs/Kconfig.binfmt"
2506 config IA32_EMULATION
2507 bool "IA32 Emulation"
2510 select COMPAT_BINFMT_ELF
2513 Include code to run legacy 32-bit programs under a
2514 64-bit kernel. You should likely turn this on, unless you're
2515 100% sure that you don't have any 32-bit programs left.
2518 tristate "IA32 a.out support"
2519 depends on IA32_EMULATION
2521 Support old a.out binaries in the 32bit emulation.
2524 bool "x32 ABI for 64-bit mode"
2525 depends on X86_64 && IA32_EMULATION
2527 Include code to run binaries for the x32 native 32-bit ABI
2528 for 64-bit processors. An x32 process gets access to the
2529 full 64-bit register file and wide data path while leaving
2530 pointers at 32 bits for smaller memory footprint.
2532 You will need a recent binutils (2.22 or later) with
2533 elf32_x86_64 support enabled to compile a kernel with this
2538 depends on IA32_EMULATION || X86_X32
2539 select ARCH_WANT_OLD_COMPAT_IPC
2542 config COMPAT_FOR_U64_ALIGNMENT
2545 config SYSVIPC_COMPAT
2557 config HAVE_ATOMIC_IOMAP
2561 config X86_DEV_DMA_OPS
2563 depends on X86_64 || STA2X11
2565 config X86_DMA_REMAP
2573 source "net/Kconfig"
2575 source "drivers/Kconfig"
2577 source "drivers/firmware/Kconfig"
2581 source "arch/x86/Kconfig.debug"
2583 source "security/Kconfig"
2585 source "crypto/Kconfig"
2587 source "arch/x86/kvm/Kconfig"
2589 source "lib/Kconfig"