xref: /linux/arch/x86/Kconfig (revision 3fda5bb420e79b357328b358409e4c547d8f0a18)

# Select 32 or 64 bit
config 64BIT
	bool "64-bit kernel" if ARCH = "x86"
	default ARCH != "i386"
	---help---
	  Say yes to build a 64-bit kernel - formerly known as x86_64
	  Say no to build a 32-bit kernel - formerly known as i386

config X86_32
	def_bool y
	depends on !64BIT

config X86_64
	def_bool y
	depends on 64BIT

### Arch settings
config X86
	def_bool y
	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
	select ANON_INODES
	select ARCH_CLOCKSOURCE_DATA
	select ARCH_DISCARD_MEMBLOCK
	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
	select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
	select ARCH_HAS_ELF_RANDOMIZE
	select ARCH_HAS_FAST_MULTIPLIER
	select ARCH_HAS_GCOV_PROFILE_ALL
	select ARCH_HAS_PMEM_API		if X86_64
	select ARCH_HAS_MMIO_FLUSH
	select ARCH_HAS_SG_CHAIN
	select ARCH_HAVE_NMI_SAFE_CMPXCHG
	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
	select ARCH_MIGHT_HAVE_PC_PARPORT
	select ARCH_MIGHT_HAVE_PC_SERIO
	select ARCH_SUPPORTS_ATOMIC_RMW
	select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
	select ARCH_SUPPORTS_INT128		if X86_64
	select ARCH_SUPPORTS_NUMA_BALANCING	if X86_64
	select ARCH_USE_BUILTIN_BSWAP
	select ARCH_USE_CMPXCHG_LOCKREF		if X86_64
	select ARCH_USE_QUEUED_RWLOCKS
	select ARCH_USE_QUEUED_SPINLOCKS
	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
	select ARCH_WANT_FRAME_POINTERS
	select ARCH_WANT_IPC_PARSE_VERSION	if X86_32
	select ARCH_WANT_OPTIONAL_GPIOLIB
	select BUILDTIME_EXTABLE_SORT
	select CLKEVT_I8253
	select CLKSRC_I8253			if X86_32
	select CLOCKSOURCE_VALIDATE_LAST_CYCLE
	select CLOCKSOURCE_WATCHDOG
	select CLONE_BACKWARDS			if X86_32
	select COMPAT_OLD_SIGACTION		if IA32_EMULATION
	select DCACHE_WORD_ACCESS
	select EDAC_ATOMIC_SCRUB
	select EDAC_SUPPORT
	select GENERIC_CLOCKEVENTS
	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
	select GENERIC_CLOCKEVENTS_MIN_ADJUST
	select GENERIC_CMOS_UPDATE
	select GENERIC_CPU_AUTOPROBE
	select GENERIC_EARLY_IOREMAP
	select GENERIC_FIND_FIRST_BIT
	select GENERIC_IOMAP
	select GENERIC_IRQ_PROBE
	select GENERIC_IRQ_SHOW
	select GENERIC_PENDING_IRQ		if SMP
	select GENERIC_SMP_IDLE_THREAD
	select GENERIC_STRNCPY_FROM_USER
	select GENERIC_STRNLEN_USER
	select GENERIC_TIME_VSYSCALL
	select HAVE_ACPI_APEI			if ACPI
	select HAVE_ACPI_APEI_NMI		if ACPI
	select HAVE_ALIGNED_STRUCT_PAGE		if SLUB
	select HAVE_AOUT			if X86_32
	select HAVE_ARCH_AUDITSYSCALL
	select HAVE_ARCH_HUGE_VMAP		if X86_64 || X86_PAE
	select HAVE_ARCH_JUMP_LABEL
	select HAVE_ARCH_KASAN			if X86_64 && SPARSEMEM_VMEMMAP
	select HAVE_ARCH_KGDB
	select HAVE_ARCH_KMEMCHECK
	select HAVE_ARCH_SECCOMP_FILTER
	select HAVE_ARCH_SOFT_DIRTY		if X86_64
	select HAVE_ARCH_TRACEHOOK
	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
	select HAVE_BPF_JIT			if X86_64
	select HAVE_CC_STACKPROTECTOR
	select HAVE_CMPXCHG_DOUBLE
	select HAVE_CMPXCHG_LOCAL
	select HAVE_CONTEXT_TRACKING		if X86_64
	select HAVE_COPY_THREAD_TLS
	select HAVE_C_RECORDMCOUNT
	select HAVE_DEBUG_KMEMLEAK
	select HAVE_DEBUG_STACKOVERFLOW
	select HAVE_DMA_API_DEBUG
	select HAVE_DMA_ATTRS
	select HAVE_DMA_CONTIGUOUS
	select HAVE_DYNAMIC_FTRACE
	select HAVE_DYNAMIC_FTRACE_WITH_REGS
	select HAVE_EFFICIENT_UNALIGNED_ACCESS
	select HAVE_FENTRY			if X86_64
	select HAVE_FTRACE_MCOUNT_RECORD
	select HAVE_FUNCTION_GRAPH_FP_TEST
	select HAVE_FUNCTION_GRAPH_TRACER
	select HAVE_FUNCTION_TRACER
	select HAVE_GENERIC_DMA_COHERENT	if X86_32
	select HAVE_HW_BREAKPOINT
	select HAVE_IDE
	select HAVE_IOREMAP_PROT
	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64
	select HAVE_IRQ_TIME_ACCOUNTING
	select HAVE_KERNEL_BZIP2
	select HAVE_KERNEL_GZIP
	select HAVE_KERNEL_LZ4
	select HAVE_KERNEL_LZMA
	select HAVE_KERNEL_LZO
	select HAVE_KERNEL_XZ
	select HAVE_KPROBES
	select HAVE_KPROBES_ON_FTRACE
	select HAVE_KRETPROBES
	select HAVE_KVM
	select HAVE_LIVEPATCH			if X86_64
	select HAVE_MEMBLOCK
	select HAVE_MEMBLOCK_NODE_MAP
	select HAVE_MIXED_BREAKPOINTS_REGS
	select HAVE_OPROFILE
	select HAVE_OPTPROBES
	select HAVE_PCSPKR_PLATFORM
	select HAVE_PERF_EVENTS
	select HAVE_PERF_EVENTS_NMI
	select HAVE_PERF_REGS
	select HAVE_PERF_USER_STACK_DUMP
	select HAVE_REGS_AND_STACK_ACCESS_API
	select HAVE_SYSCALL_TRACEPOINTS
	select HAVE_UID16			if X86_32 || IA32_EMULATION
	select HAVE_UNSTABLE_SCHED_CLOCK
	select HAVE_USER_RETURN_NOTIFIER
	select IRQ_FORCED_THREADING
	select MODULES_USE_ELF_RELA		if X86_64
	select MODULES_USE_ELF_REL		if X86_32
	select OLD_SIGACTION			if X86_32
	select OLD_SIGSUSPEND3			if X86_32 || IA32_EMULATION
	select PERF_EVENTS
	select RTC_LIB
	select SPARSE_IRQ
	select SRCU
	select SYSCTL_EXCEPTION_TRACE
	select USER_STACKTRACE_SUPPORT
	select VIRT_TO_BUS
	select X86_DEV_DMA_OPS			if X86_64
	select X86_FEATURE_NAMES		if PROC_FS

config INSTRUCTION_DECODER
	def_bool y
	depends on KPROBES || PERF_EVENTS || UPROBES

config PERF_EVENTS_INTEL_UNCORE
	def_bool y
	depends on PERF_EVENTS && CPU_SUP_INTEL && PCI

config OUTPUT_FORMAT
	string
	default "elf32-i386" if X86_32
	default "elf64-x86-64" if X86_64

config ARCH_DEFCONFIG
	string
	default "arch/x86/configs/i386_defconfig" if X86_32
	default "arch/x86/configs/x86_64_defconfig" if X86_64

config LOCKDEP_SUPPORT
	def_bool y

config STACKTRACE_SUPPORT
	def_bool y

config HAVE_LATENCYTOP_SUPPORT
	def_bool y

config MMU
	def_bool y

config SBUS
	bool

config NEED_DMA_MAP_STATE
	def_bool y
	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB

config NEED_SG_DMA_LENGTH
	def_bool y

config GENERIC_ISA_DMA
	def_bool y
	depends on ISA_DMA_API

config GENERIC_BUG
	def_bool y
	depends on BUG
	select GENERIC_BUG_RELATIVE_POINTERS if X86_64

config GENERIC_BUG_RELATIVE_POINTERS
	bool

config GENERIC_HWEIGHT
	def_bool y

config ARCH_MAY_HAVE_PC_FDC
	def_bool y
	depends on ISA_DMA_API

config RWSEM_XCHGADD_ALGORITHM
	def_bool y

config GENERIC_CALIBRATE_DELAY
	def_bool y

config ARCH_HAS_CPU_RELAX
	def_bool y

config ARCH_HAS_CACHE_LINE_SIZE
	def_bool y

config HAVE_SETUP_PER_CPU_AREA
	def_bool y

config NEED_PER_CPU_EMBED_FIRST_CHUNK
	def_bool y

config NEED_PER_CPU_PAGE_FIRST_CHUNK
	def_bool y

config ARCH_HIBERNATION_POSSIBLE
	def_bool y

config ARCH_SUSPEND_POSSIBLE
	def_bool y

config ARCH_WANT_HUGE_PMD_SHARE
	def_bool y

config ARCH_WANT_GENERAL_HUGETLB
	def_bool y

config ZONE_DMA32
	def_bool y if X86_64

config AUDIT_ARCH
	def_bool y if X86_64

config ARCH_SUPPORTS_OPTIMIZED_INLINING
	def_bool y

config ARCH_SUPPORTS_DEBUG_PAGEALLOC
	def_bool y

config KASAN_SHADOW_OFFSET
	hex
	depends on KASAN
	default 0xdffffc0000000000

config HAVE_INTEL_TXT
	def_bool y
	depends on INTEL_IOMMU && ACPI

config X86_32_SMP
	def_bool y
	depends on X86_32 && SMP

config X86_64_SMP
	def_bool y
	depends on X86_64 && SMP

config X86_32_LAZY_GS
	def_bool y
	depends on X86_32 && !CC_STACKPROTECTOR

config ARCH_HWEIGHT_CFLAGS
	string
	default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
	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

config ARCH_SUPPORTS_UPROBES
	def_bool y

config FIX_EARLYCON_MEM
	def_bool y

config PGTABLE_LEVELS
	int
	default 4 if X86_64
	default 3 if X86_PAE
	default 2

source "init/Kconfig"
source "kernel/Kconfig.freezer"

menu "Processor type and features"

config ZONE_DMA
	bool "DMA memory allocation support" if EXPERT
	default y
	help
	  DMA memory allocation support allows devices with less than 32-bit
	  addressing to allocate within the first 16MB of address space.
	  Disable if no such devices will be used.

	  If unsure, say Y.

config SMP
	bool "Symmetric multi-processing support"
	---help---
	  This enables support for systems with more than one CPU. If you have
	  a system with only one CPU, say N. If you have a system with more
	  than one CPU, say Y.

	  If you say N here, the kernel will run on uni- and multiprocessor
	  machines, but will use only one CPU of a multiprocessor machine. If
	  you say Y here, the kernel will run on many, but not all,
	  uniprocessor machines. On a uniprocessor machine, the kernel
	  will run faster if you say N here.

	  Note that if you say Y here and choose architecture "586" or
	  "Pentium" under "Processor family", the kernel will not work on 486
	  architectures. Similarly, multiprocessor kernels for the "PPro"
	  architecture may not work on all Pentium based boards.

	  People using multiprocessor machines who say Y here should also say
	  Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
	  Management" code will be disabled if you say Y here.

	  See also <file:Documentation/x86/i386/IO-APIC.txt>,
	  <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
	  <http://www.tldp.org/docs.html#howto>.

	  If you don't know what to do here, say N.

config X86_FEATURE_NAMES
	bool "Processor feature human-readable names" if EMBEDDED
	default y
	---help---
	  This option compiles in a table of x86 feature bits and corresponding
	  names.  This is required to support /proc/cpuinfo and a few kernel
	  messages.  You can disable this to save space, at the expense of
	  making those few kernel messages show numeric feature bits instead.

	  If in doubt, say Y.

config X86_FAST_FEATURE_TESTS
	bool "Fast CPU feature tests" if EMBEDDED
	default y
	---help---
	  Some fast-paths in the kernel depend on the capabilities of the CPU.
	  Say Y here for the kernel to patch in the appropriate code at runtime
	  based on the capabilities of the CPU. The infrastructure for patching
	  code at runtime takes up some additional space; space-constrained
	  embedded systems may wish to say N here to produce smaller, slightly
	  slower code.

config X86_X2APIC
	bool "Support x2apic"
	depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
	---help---
	  This enables x2apic support on CPUs that have this feature.

	  This allows 32-bit apic IDs (so it can support very large systems),
	  and accesses the local apic via MSRs not via mmio.

	  If you don't know what to do here, say N.

config X86_MPPARSE
	bool "Enable MPS table" if ACPI || SFI
	default y
	depends on X86_LOCAL_APIC
	---help---
	  For old smp systems that do not have proper acpi support. Newer systems
	  (esp with 64bit cpus) with acpi support, MADT and DSDT will override it

config X86_BIGSMP
	bool "Support for big SMP systems with more than 8 CPUs"
	depends on X86_32 && SMP
	---help---
	  This option is needed for the systems that have more than 8 CPUs

config GOLDFISH
       def_bool y
       depends on X86_GOLDFISH

if X86_32
config X86_EXTENDED_PLATFORM
	bool "Support for extended (non-PC) x86 platforms"
	default y
	---help---
	  If you disable this option then the kernel will only support
	  standard PC platforms. (which covers the vast majority of
	  systems out there.)

	  If you enable this option then you'll be able to select support
	  for the following (non-PC) 32 bit x86 platforms:
		Goldfish (Android emulator)
		AMD Elan
		RDC R-321x SoC
		SGI 320/540 (Visual Workstation)
		STA2X11-based (e.g. Northville)
		Moorestown MID devices

	  If you have one of these systems, or if you want to build a
	  generic distribution kernel, say Y here - otherwise say N.
endif

if X86_64
config X86_EXTENDED_PLATFORM
	bool "Support for extended (non-PC) x86 platforms"
	default y
	---help---
	  If you disable this option then the kernel will only support
	  standard PC platforms. (which covers the vast majority of
	  systems out there.)

	  If you enable this option then you'll be able to select support
	  for the following (non-PC) 64 bit x86 platforms:
		Numascale NumaChip
		ScaleMP vSMP
		SGI Ultraviolet

	  If you have one of these systems, or if you want to build a
	  generic distribution kernel, say Y here - otherwise say N.
endif
# This is an alphabetically sorted list of 64 bit extended platforms
# Please maintain the alphabetic order if and when there are additions
config X86_NUMACHIP
	bool "Numascale NumaChip"
	depends on X86_64
	depends on X86_EXTENDED_PLATFORM
	depends on NUMA
	depends on SMP
	depends on X86_X2APIC
	depends on PCI_MMCONFIG
	---help---
	  Adds support for Numascale NumaChip large-SMP systems. Needed to
	  enable more than ~168 cores.
	  If you don't have one of these, you should say N here.

config X86_VSMP
	bool "ScaleMP vSMP"
	select HYPERVISOR_GUEST
	select PARAVIRT
	depends on X86_64 && PCI
	depends on X86_EXTENDED_PLATFORM
	depends on SMP
	---help---
	  Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
	  supposed to run on these EM64T-based machines.  Only choose this option
	  if you have one of these machines.

config X86_UV
	bool "SGI Ultraviolet"
	depends on X86_64
	depends on X86_EXTENDED_PLATFORM
	depends on NUMA
	depends on X86_X2APIC
	depends on PCI
	---help---
	  This option is needed in order to support SGI Ultraviolet systems.
	  If you don't have one of these, you should say N here.

# Following is an alphabetically sorted list of 32 bit extended platforms
# Please maintain the alphabetic order if and when there are additions

config X86_GOLDFISH
       bool "Goldfish (Virtual Platform)"
       depends on X86_EXTENDED_PLATFORM
       ---help---
	 Enable support for the Goldfish virtual platform used primarily
	 for Android development. Unless you are building for the Android
	 Goldfish emulator say N here.

config X86_INTEL_CE
	bool "CE4100 TV platform"
	depends on PCI
	depends on PCI_GODIRECT
	depends on X86_IO_APIC
	depends on X86_32
	depends on X86_EXTENDED_PLATFORM
	select X86_REBOOTFIXUPS
	select OF
	select OF_EARLY_FLATTREE
	---help---
	  Select for the Intel CE media processor (CE4100) SOC.
	  This option compiles in support for the CE4100 SOC for settop
	  boxes and media devices.

config X86_INTEL_MID
	bool "Intel MID platform support"
	depends on X86_EXTENDED_PLATFORM
	depends on X86_PLATFORM_DEVICES
	depends on PCI
	depends on X86_64 || (PCI_GOANY && X86_32)
	depends on X86_IO_APIC
	select SFI
	select I2C
	select DW_APB_TIMER
	select APB_TIMER
	select INTEL_SCU_IPC
	select MFD_INTEL_MSIC
	---help---
	  Select to build a kernel capable of supporting Intel MID (Mobile
	  Internet Device) platform systems which do not have the PCI legacy
	  interfaces. If you are building for a PC class system say N here.

	  Intel MID platforms are based on an Intel processor and chipset which
	  consume less power than most of the x86 derivatives.

config X86_INTEL_QUARK
	bool "Intel Quark platform support"
	depends on X86_32
	depends on X86_EXTENDED_PLATFORM
	depends on X86_PLATFORM_DEVICES
	depends on X86_TSC
	depends on PCI
	depends on PCI_GOANY
	depends on X86_IO_APIC
	select IOSF_MBI
	select INTEL_IMR
	select COMMON_CLK
	---help---
	  Select to include support for Quark X1000 SoC.
	  Say Y here if you have a Quark based system such as the Arduino
	  compatible Intel Galileo.

config X86_INTEL_LPSS
	bool "Intel Low Power Subsystem Support"
	depends on ACPI
	select COMMON_CLK
	select PINCTRL
	---help---
	  Select to build support for Intel Low Power Subsystem such as
	  found on Intel Lynxpoint PCH. Selecting this option enables
	  things like clock tree (common clock framework) and pincontrol
	  which are needed by the LPSS peripheral drivers.

config X86_AMD_PLATFORM_DEVICE
	bool "AMD ACPI2Platform devices support"
	depends on ACPI
	select COMMON_CLK
	select PINCTRL
	---help---
	  Select to interpret AMD specific ACPI device to platform device
	  such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
	  I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
	  implemented under PINCTRL subsystem.

config IOSF_MBI
	tristate "Intel SoC IOSF Sideband support for SoC platforms"
	depends on PCI
	---help---
	  This option enables sideband register access support for Intel SoC
	  platforms. On these platforms the IOSF sideband is used in lieu of
	  MSR's for some register accesses, mostly but not limited to thermal
	  and power. Drivers may query the availability of this device to
	  determine if they need the sideband in order to work on these
	  platforms. The sideband is available on the following SoC products.
	  This list is not meant to be exclusive.
	   - BayTrail
	   - Braswell
	   - Quark

	  You should say Y if you are running a kernel on one of these SoC's.

config IOSF_MBI_DEBUG
	bool "Enable IOSF sideband access through debugfs"
	depends on IOSF_MBI && DEBUG_FS
	---help---
	  Select this option to expose the IOSF sideband access registers (MCR,
	  MDR, MCRX) through debugfs to write and read register information from
	  different units on the SoC. This is most useful for obtaining device
	  state information for debug and analysis. As this is a general access
	  mechanism, users of this option would have specific knowledge of the
	  device they want to access.

	  If you don't require the option or are in doubt, say N.

config X86_RDC321X
	bool "RDC R-321x SoC"
	depends on X86_32
	depends on X86_EXTENDED_PLATFORM
	select M486
	select X86_REBOOTFIXUPS
	---help---
	  This option is needed for RDC R-321x system-on-chip, also known
	  as R-8610-(G).
	  If you don't have one of these chips, you should say N here.

config X86_32_NON_STANDARD
	bool "Support non-standard 32-bit SMP architectures"
	depends on X86_32 && SMP
	depends on X86_EXTENDED_PLATFORM
	---help---
	  This option compiles in the bigsmp and STA2X11 default
	  subarchitectures.  It is intended for a generic binary
	  kernel. If you select them all, kernel will probe it one by
	  one and will fallback to default.

# Alphabetically sorted list of Non standard 32 bit platforms

config X86_SUPPORTS_MEMORY_FAILURE
	def_bool y
	# MCE code calls memory_failure():
	depends on X86_MCE
	# On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
	# On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
	depends on X86_64 || !SPARSEMEM
	select ARCH_SUPPORTS_MEMORY_FAILURE

config STA2X11
	bool "STA2X11 Companion Chip Support"
	depends on X86_32_NON_STANDARD && PCI
	select X86_DEV_DMA_OPS
	select X86_DMA_REMAP
	select SWIOTLB
	select MFD_STA2X11
	select ARCH_REQUIRE_GPIOLIB
	default n
	---help---
	  This adds support for boards based on the STA2X11 IO-Hub,
	  a.k.a. "ConneXt". The chip is used in place of the standard
	  PC chipset, so all "standard" peripherals are missing. If this
	  option is selected the kernel will still be able to boot on
	  standard PC machines.

config X86_32_IRIS
	tristate "Eurobraille/Iris poweroff module"
	depends on X86_32
	---help---
	  The Iris machines from EuroBraille do not have APM or ACPI support
	  to shut themselves down properly.  A special I/O sequence is
	  needed to do so, which is what this module does at
	  kernel shutdown.

	  This is only for Iris machines from EuroBraille.

	  If unused, say N.

config SCHED_OMIT_FRAME_POINTER
	def_bool y
	prompt "Single-depth WCHAN output"
	depends on X86
	---help---
	  Calculate simpler /proc/<PID>/wchan values. If this option
	  is disabled then wchan values will recurse back to the
	  caller function. This provides more accurate wchan values,
	  at the expense of slightly more scheduling overhead.

	  If in doubt, say "Y".

menuconfig HYPERVISOR_GUEST
	bool "Linux guest support"
	---help---
	  Say Y here to enable options for running Linux under various hyper-
	  visors. This option enables basic hypervisor detection and platform
	  setup.

	  If you say N, all options in this submenu will be skipped and
	  disabled, and Linux guest support won't be built in.

if HYPERVISOR_GUEST

config PARAVIRT
	bool "Enable paravirtualization code"
	---help---
	  This changes the kernel so it can modify itself when it is run
	  under a hypervisor, potentially improving performance significantly
	  over full virtualization.  However, when run without a hypervisor
	  the kernel is theoretically slower and slightly larger.

config PARAVIRT_DEBUG
	bool "paravirt-ops debugging"
	depends on PARAVIRT && DEBUG_KERNEL
	---help---
	  Enable to debug paravirt_ops internals.  Specifically, BUG if
	  a paravirt_op is missing when it is called.

config PARAVIRT_SPINLOCKS
	bool "Paravirtualization layer for spinlocks"
	depends on PARAVIRT && SMP
	select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
	---help---
	  Paravirtualized spinlocks allow a pvops backend to replace the
	  spinlock implementation with something virtualization-friendly
	  (for example, block the virtual CPU rather than spinning).

	  It has a minimal impact on native kernels and gives a nice performance
	  benefit on paravirtualized KVM / Xen kernels.

	  If you are unsure how to answer this question, answer Y.

config QUEUED_LOCK_STAT
	bool "Paravirt queued spinlock statistics"
	depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
	---help---
	  Enable the collection of statistical data on the slowpath
	  behavior of paravirtualized queued spinlocks and report
	  them on debugfs.

source "arch/x86/xen/Kconfig"

config KVM_GUEST
	bool "KVM Guest support (including kvmclock)"
	depends on PARAVIRT
	select PARAVIRT_CLOCK
	default y
	---help---
	  This option enables various optimizations for running under the KVM
	  hypervisor. It includes a paravirtualized clock, so that instead
	  of relying on a PIT (or probably other) emulation by the
	  underlying device model, the host provides the guest with
	  timing infrastructure such as time of day, and system time

config KVM_DEBUG_FS
	bool "Enable debug information for KVM Guests in debugfs"
	depends on KVM_GUEST && DEBUG_FS
	default n
	---help---
	  This option enables collection of various statistics for KVM guest.
	  Statistics are displayed in debugfs filesystem. Enabling this option
	  may incur significant overhead.

source "arch/x86/lguest/Kconfig"

config PARAVIRT_TIME_ACCOUNTING
	bool "Paravirtual steal time accounting"
	depends on PARAVIRT
	default n
	---help---
	  Select this option to enable fine granularity task steal time
	  accounting. Time spent executing other tasks in parallel with
	  the current vCPU is discounted from the vCPU power. To account for
	  that, there can be a small performance impact.

	  If in doubt, say N here.

config PARAVIRT_CLOCK
	bool

endif #HYPERVISOR_GUEST

config NO_BOOTMEM
	def_bool y

source "arch/x86/Kconfig.cpu"

config HPET_TIMER
	def_bool X86_64
	prompt "HPET Timer Support" if X86_32
	---help---
	  Use the IA-PC HPET (High Precision Event Timer) to manage
	  time in preference to the PIT and RTC, if a HPET is
	  present.
	  HPET is the next generation timer replacing legacy 8254s.
	  The HPET provides a stable time base on SMP
	  systems, unlike the TSC, but it is more expensive to access,
	  as it is off-chip.  You can find the HPET spec at
	  <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.

	  You can safely choose Y here.  However, HPET will only be
	  activated if the platform and the BIOS support this feature.
	  Otherwise the 8254 will be used for timing services.

	  Choose N to continue using the legacy 8254 timer.

config HPET_EMULATE_RTC
	def_bool y
	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)

config APB_TIMER
       def_bool y if X86_INTEL_MID
       prompt "Intel MID APB Timer Support" if X86_INTEL_MID
       select DW_APB_TIMER
       depends on X86_INTEL_MID && SFI
       help
         APB timer is the replacement for 8254, HPET on X86 MID platforms.
         The APBT provides a stable time base on SMP
         systems, unlike the TSC, but it is more expensive to access,
         as it is off-chip. APB timers are always running regardless of CPU
         C states, they are used as per CPU clockevent device when possible.

# Mark as expert because too many people got it wrong.
# The code disables itself when not needed.
config DMI
	default y
	select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
	bool "Enable DMI scanning" if EXPERT
	---help---
	  Enabled scanning of DMI to identify machine quirks. Say Y
	  here unless you have verified that your setup is not
	  affected by entries in the DMI blacklist. Required by PNP
	  BIOS code.

config GART_IOMMU
	bool "Old AMD GART IOMMU support"
	select SWIOTLB
	depends on X86_64 && PCI && AMD_NB
	---help---
	  Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
	  GART based hardware IOMMUs.

	  The GART supports full DMA access for devices with 32-bit access
	  limitations, on systems with more than 3 GB. This is usually needed
	  for USB, sound, many IDE/SATA chipsets and some other devices.

	  Newer systems typically have a modern AMD IOMMU, supported via
	  the CONFIG_AMD_IOMMU=y config option.

	  In normal configurations this driver is only active when needed:
	  there's more than 3 GB of memory and the system contains a
	  32-bit limited device.

	  If unsure, say Y.

config CALGARY_IOMMU
	bool "IBM Calgary IOMMU support"
	select SWIOTLB
	depends on X86_64 && PCI
	---help---
	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
	  systems. Needed to run systems with more than 3GB of memory
	  properly with 32-bit PCI devices that do not support DAC
	  (Double Address Cycle). Calgary also supports bus level
	  isolation, where all DMAs pass through the IOMMU.  This
	  prevents them from going anywhere except their intended
	  destination. This catches hard-to-find kernel bugs and
	  mis-behaving drivers and devices that do not use the DMA-API
	  properly to set up their DMA buffers.  The IOMMU can be
	  turned off at boot time with the iommu=off parameter.
	  Normally the kernel will make the right choice by itself.
	  If unsure, say Y.

config CALGARY_IOMMU_ENABLED_BY_DEFAULT
	def_bool y
	prompt "Should Calgary be enabled by default?"
	depends on CALGARY_IOMMU
	---help---
	  Should Calgary be enabled by default? if you choose 'y', Calgary
	  will be used (if it exists). If you choose 'n', Calgary will not be
	  used even if it exists. If you choose 'n' and would like to use
	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
	  If unsure, say Y.

# need this always selected by IOMMU for the VIA workaround
config SWIOTLB
	def_bool y if X86_64
	---help---
	  Support for software bounce buffers used on x86-64 systems
	  which don't have a hardware IOMMU. Using this PCI devices
	  which can only access 32-bits of memory can be used on systems
	  with more than 3 GB of memory.
	  If unsure, say Y.

config IOMMU_HELPER
	def_bool y
	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU

config MAXSMP
	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
	depends on X86_64 && SMP && DEBUG_KERNEL
	select CPUMASK_OFFSTACK
	---help---
	  Enable maximum number of CPUS and NUMA Nodes for this architecture.
	  If unsure, say N.

config NR_CPUS
	int "Maximum number of CPUs" if SMP && !MAXSMP
	range 2 8 if SMP && X86_32 && !X86_BIGSMP
	range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
	range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
	default "1" if !SMP
	default "8192" if MAXSMP
	default "32" if SMP && X86_BIGSMP
	default "8" if SMP && X86_32
	default "64" if SMP
	---help---
	  This allows you to specify the maximum number of CPUs which this
	  kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum
	  supported value is 8192, otherwise the maximum value is 512.  The
	  minimum value which makes sense is 2.

	  This is purely to save memory - each supported CPU adds
	  approximately eight kilobytes to the kernel image.

config SCHED_SMT
	bool "SMT (Hyperthreading) scheduler support"
	depends on SMP
	---help---
	  SMT scheduler support improves the CPU scheduler's decision making
	  when dealing with Intel Pentium 4 chips with HyperThreading at a
	  cost of slightly increased overhead in some places. If unsure say
	  N here.

config SCHED_MC
	def_bool y
	prompt "Multi-core scheduler support"
	depends on SMP
	---help---
	  Multi-core scheduler support improves the CPU scheduler's decision
	  making when dealing with multi-core CPU chips at a cost of slightly
	  increased overhead in some places. If unsure say N here.

source "kernel/Kconfig.preempt"

config UP_LATE_INIT
       def_bool y
       depends on !SMP && X86_LOCAL_APIC

config X86_UP_APIC
	bool "Local APIC support on uniprocessors" if !PCI_MSI
	default PCI_MSI
	depends on X86_32 && !SMP && !X86_32_NON_STANDARD
	---help---
	  A local APIC (Advanced Programmable Interrupt Controller) is an
	  integrated interrupt controller in the CPU. If you have a single-CPU
	  system which has a processor with a local APIC, you can say Y here to
	  enable and use it. If you say Y here even though your machine doesn't
	  have a local APIC, then the kernel will still run with no slowdown at
	  all. The local APIC supports CPU-generated self-interrupts (timer,
	  performance counters), and the NMI watchdog which detects hard
	  lockups.

config X86_UP_IOAPIC
	bool "IO-APIC support on uniprocessors"
	depends on X86_UP_APIC
	---help---
	  An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
	  SMP-capable replacement for PC-style interrupt controllers. Most
	  SMP systems and many recent uniprocessor systems have one.

	  If you have a single-CPU system with an IO-APIC, you can say Y here
	  to use it. If you say Y here even though your machine doesn't have
	  an IO-APIC, then the kernel will still run with no slowdown at all.

config X86_LOCAL_APIC
	def_bool y
	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
	select IRQ_DOMAIN_HIERARCHY
	select PCI_MSI_IRQ_DOMAIN if PCI_MSI

config X86_IO_APIC
	def_bool y
	depends on X86_LOCAL_APIC || X86_UP_IOAPIC

config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
	bool "Reroute for broken boot IRQs"
	depends on X86_IO_APIC
	---help---
	  This option enables a workaround that fixes a source of
	  spurious interrupts. This is recommended when threaded
	  interrupt handling is used on systems where the generation of
	  superfluous "boot interrupts" cannot be disabled.

	  Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
	  entry in the chipset's IO-APIC is masked (as, e.g. the RT
	  kernel does during interrupt handling). On chipsets where this
	  boot IRQ generation cannot be disabled, this workaround keeps
	  the original IRQ line masked so that only the equivalent "boot
	  IRQ" is delivered to the CPUs. The workaround also tells the
	  kernel to set up the IRQ handler on the boot IRQ line. In this
	  way only one interrupt is delivered to the kernel. Otherwise
	  the spurious second interrupt may cause the kernel to bring
	  down (vital) interrupt lines.

	  Only affects "broken" chipsets. Interrupt sharing may be
	  increased on these systems.

config X86_MCE
	bool "Machine Check / overheating reporting"
	select GENERIC_ALLOCATOR
	default y
	---help---
	  Machine Check support allows the processor to notify the
	  kernel if it detects a problem (e.g. overheating, data corruption).
	  The action the kernel takes depends on the severity of the problem,
	  ranging from warning messages to halting the machine.

config X86_MCE_INTEL
	def_bool y
	prompt "Intel MCE features"
	depends on X86_MCE && X86_LOCAL_APIC
	---help---
	   Additional support for intel specific MCE features such as
	   the thermal monitor.

config X86_MCE_AMD
	def_bool y
	prompt "AMD MCE features"
	depends on X86_MCE && X86_LOCAL_APIC
	---help---
	   Additional support for AMD specific MCE features such as
	   the DRAM Error Threshold.

config X86_ANCIENT_MCE
	bool "Support for old Pentium 5 / WinChip machine checks"
	depends on X86_32 && X86_MCE
	---help---
	  Include support for machine check handling on old Pentium 5 or WinChip
	  systems. These typically need to be enabled explicitly on the command
	  line.

config X86_MCE_THRESHOLD
	depends on X86_MCE_AMD || X86_MCE_INTEL
	def_bool y

config X86_MCE_INJECT
	depends on X86_MCE
	tristate "Machine check injector support"
	---help---
	  Provide support for injecting machine checks for testing purposes.
	  If you don't know what a machine check is and you don't do kernel
	  QA it is safe to say n.

config X86_THERMAL_VECTOR
	def_bool y
	depends on X86_MCE_INTEL

config X86_LEGACY_VM86
	bool "Legacy VM86 support"
	default n
	depends on X86_32
	---help---
	  This option allows user programs to put the CPU into V8086
	  mode, which is an 80286-era approximation of 16-bit real mode.

	  Some very old versions of X and/or vbetool require this option
	  for user mode setting.  Similarly, DOSEMU will use it if
	  available to accelerate real mode DOS programs.  However, any
	  recent version of DOSEMU, X, or vbetool should be fully
	  functional even without kernel VM86 support, as they will all
	  fall back to software emulation. Nevertheless, if you are using
	  a 16-bit DOS program where 16-bit performance matters, vm86
	  mode might be faster than emulation and you might want to
	  enable this option.

	  Note that any app that works on a 64-bit kernel is unlikely to
	  need this option, as 64-bit kernels don't, and can't, support
	  V8086 mode. This option is also unrelated to 16-bit protected
	  mode and is not needed to run most 16-bit programs under Wine.

	  Enabling this option increases the complexity of the kernel
	  and slows down exception handling a tiny bit.

	  If unsure, say N here.

config VM86
       bool
       default X86_LEGACY_VM86

config X86_16BIT
	bool "Enable support for 16-bit segments" if EXPERT
	default y
	depends on MODIFY_LDT_SYSCALL
	---help---
	  This option is required by programs like Wine to run 16-bit
	  protected mode legacy code on x86 processors.  Disabling
	  this option saves about 300 bytes on i386, or around 6K text
	  plus 16K runtime memory on x86-64,

config X86_ESPFIX32
	def_bool y
	depends on X86_16BIT && X86_32

config X86_ESPFIX64
	def_bool y
	depends on X86_16BIT && X86_64

config X86_VSYSCALL_EMULATION
       bool "Enable vsyscall emulation" if EXPERT
       default y
       depends on X86_64
       ---help---
	 This enables emulation of the legacy vsyscall page.  Disabling
	 it is roughly equivalent to booting with vsyscall=none, except
	 that it will also disable the helpful warning if a program
	 tries to use a vsyscall.  With this option set to N, offending
	 programs will just segfault, citing addresses of the form
	 0xffffffffff600?00.

	 This option is required by many programs built before 2013, and
	 care should be used even with newer programs if set to N.

	 Disabling this option saves about 7K of kernel size and
	 possibly 4K of additional runtime pagetable memory.

config TOSHIBA
	tristate "Toshiba Laptop support"
	depends on X86_32
	---help---
	  This adds a driver to safely access the System Management Mode of
	  the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
	  not work on models with a Phoenix BIOS. The System Management Mode
	  is used to set the BIOS and power saving options on Toshiba portables.

	  For information on utilities to make use of this driver see the
	  Toshiba Linux utilities web site at:
	  <http://www.buzzard.org.uk/toshiba/>.

	  Say Y if you intend to run this kernel on a Toshiba portable.
	  Say N otherwise.

config I8K
	tristate "Dell i8k legacy laptop support"
	select HWMON
	select SENSORS_DELL_SMM
	---help---
	  This option enables legacy /proc/i8k userspace interface in hwmon
	  dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
	  temperature and allows controlling fan speeds of Dell laptops via
	  System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
	  it reports also power and hotkey status. For fan speed control is
	  needed userspace package i8kutils.

	  Say Y if you intend to run this kernel on old Dell laptops or want to
	  use userspace package i8kutils.
	  Say N otherwise.

config X86_REBOOTFIXUPS
	bool "Enable X86 board specific fixups for reboot"
	depends on X86_32
	---help---
	  This enables chipset and/or board specific fixups to be done
	  in order to get reboot to work correctly. This is only needed on
	  some combinations of hardware and BIOS. The symptom, for which
	  this config is intended, is when reboot ends with a stalled/hung
	  system.

	  Currently, the only fixup is for the Geode machines using
	  CS5530A and CS5536 chipsets and the RDC R-321x SoC.

	  Say Y if you want to enable the fixup. Currently, it's safe to
	  enable this option even if you don't need it.
	  Say N otherwise.

config MICROCODE
	bool "CPU microcode loading support"
	default y
	depends on CPU_SUP_AMD || CPU_SUP_INTEL
	depends on BLK_DEV_INITRD
	select FW_LOADER
	---help---

	  If you say Y here, you will be able to update the microcode on
	  certain Intel and AMD processors. The Intel support is for the
	  IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
	  Xeon etc. The AMD support is for families 0x10 and later. You will
	  obviously need the actual microcode binary data itself which is not
	  shipped with the Linux kernel.

	  This option selects the general module only, you need to select
	  at least one vendor specific module as well.

	  To compile this driver as a module, choose M here: the module
	  will be called microcode.

config MICROCODE_INTEL
	bool "Intel microcode loading support"
	depends on MICROCODE
	default MICROCODE
	select FW_LOADER
	---help---
	  This options enables microcode patch loading support for Intel
	  processors.

	  For the current Intel microcode data package go to
	  <https://downloadcenter.intel.com> and search for
	  'Linux Processor Microcode Data File'.

config MICROCODE_AMD
	bool "AMD microcode loading support"
	depends on MICROCODE
	select FW_LOADER
	---help---
	  If you select this option, microcode patch loading support for AMD
	  processors will be enabled.

config MICROCODE_OLD_INTERFACE
	def_bool y
	depends on MICROCODE

config X86_MSR
	tristate "/dev/cpu/*/msr - Model-specific register support"
	---help---
	  This device gives privileged processes access to the x86
	  Model-Specific Registers (MSRs).  It is a character device with
	  major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
	  MSR accesses are directed to a specific CPU on multi-processor
	  systems.

config X86_CPUID
	tristate "/dev/cpu/*/cpuid - CPU information support"
	---help---
	  This device gives processes access to the x86 CPUID instruction to
	  be executed on a specific processor.  It is a character device
	  with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
	  /dev/cpu/31/cpuid.

choice
	prompt "High Memory Support"
	default HIGHMEM4G
	depends on X86_32

config NOHIGHMEM
	bool "off"
	---help---
	  Linux can use up to 64 Gigabytes of physical memory on x86 systems.
	  However, the address space of 32-bit x86 processors is only 4
	  Gigabytes large. That means that, if you have a large amount of
	  physical memory, not all of it can be "permanently mapped" by the
	  kernel. The physical memory that's not permanently mapped is called
	  "high memory".

	  If you are compiling a kernel which will never run on a machine with
	  more than 1 Gigabyte total physical RAM, answer "off" here (default
	  choice and suitable for most users). This will result in a "3GB/1GB"
	  split: 3GB are mapped so that each process sees a 3GB virtual memory
	  space and the remaining part of the 4GB virtual memory space is used
	  by the kernel to permanently map as much physical memory as
	  possible.

	  If the machine has between 1 and 4 Gigabytes physical RAM, then
	  answer "4GB" here.

	  If more than 4 Gigabytes is used then answer "64GB" here. This
	  selection turns Intel PAE (Physical Address Extension) mode on.
	  PAE implements 3-level paging on IA32 processors. PAE is fully
	  supported by Linux, PAE mode is implemented on all recent Intel
	  processors (Pentium Pro and better). NOTE: If you say "64GB" here,
	  then the kernel will not boot on CPUs that don't support PAE!

	  The actual amount of total physical memory will either be
	  auto detected or can be forced by using a kernel command line option
	  such as "mem=256M". (Try "man bootparam" or see the documentation of
	  your boot loader (lilo or loadlin) about how to pass options to the
	  kernel at boot time.)

	  If unsure, say "off".

config HIGHMEM4G
	bool "4GB"
	---help---
	  Select this if you have a 32-bit processor and between 1 and 4
	  gigabytes of physical RAM.

config HIGHMEM64G
	bool "64GB"
	depends on !M486
	select X86_PAE
	---help---
	  Select this if you have a 32-bit processor and more than 4
	  gigabytes of physical RAM.

endchoice

choice
	prompt "Memory split" if EXPERT
	default VMSPLIT_3G
	depends on X86_32
	---help---
	  Select the desired split between kernel and user memory.

	  If the address range available to the kernel is less than the
	  physical memory installed, the remaining memory will be available
	  as "high memory". Accessing high memory is a little more costly
	  than low memory, as it needs to be mapped into the kernel first.
	  Note that increasing the kernel address space limits the range
	  available to user programs, making the address space there
	  tighter.  Selecting anything other than the default 3G/1G split
	  will also likely make your kernel incompatible with binary-only
	  kernel modules.

	  If you are not absolutely sure what you are doing, leave this
	  option alone!

	config VMSPLIT_3G
		bool "3G/1G user/kernel split"
	config VMSPLIT_3G_OPT
		depends on !X86_PAE
		bool "3G/1G user/kernel split (for full 1G low memory)"
	config VMSPLIT_2G
		bool "2G/2G user/kernel split"
	config VMSPLIT_2G_OPT
		depends on !X86_PAE
		bool "2G/2G user/kernel split (for full 2G low memory)"
	config VMSPLIT_1G
		bool "1G/3G user/kernel split"
endchoice

config PAGE_OFFSET
	hex
	default 0xB0000000 if VMSPLIT_3G_OPT
	default 0x80000000 if VMSPLIT_2G
	default 0x78000000 if VMSPLIT_2G_OPT
	default 0x40000000 if VMSPLIT_1G
	default 0xC0000000
	depends on X86_32

config HIGHMEM
	def_bool y
	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)

config X86_PAE
	bool "PAE (Physical Address Extension) Support"
	depends on X86_32 && !HIGHMEM4G
	select SWIOTLB
	---help---
	  PAE is required for NX support, and furthermore enables
	  larger swapspace support for non-overcommit purposes. It
	  has the cost of more pagetable lookup overhead, and also
	  consumes more pagetable space per process.

config ARCH_PHYS_ADDR_T_64BIT
	def_bool y
	depends on X86_64 || X86_PAE

config ARCH_DMA_ADDR_T_64BIT
	def_bool y
	depends on X86_64 || HIGHMEM64G

config X86_DIRECT_GBPAGES
	def_bool y
	depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
	---help---
	  Certain kernel features effectively disable kernel
	  linear 1 GB mappings (even if the CPU otherwise
	  supports them), so don't confuse the user by printing
	  that we have them enabled.

# Common NUMA Features
config NUMA
	bool "Numa Memory Allocation and Scheduler Support"
	depends on SMP
	depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
	default y if X86_BIGSMP
	---help---
	  Enable NUMA (Non Uniform Memory Access) support.

	  The kernel will try to allocate memory used by a CPU on the
	  local memory controller of the CPU and add some more
	  NUMA awareness to the kernel.

	  For 64-bit this is recommended if the system is Intel Core i7
	  (or later), AMD Opteron, or EM64T NUMA.

	  For 32-bit this is only needed if you boot a 32-bit
	  kernel on a 64-bit NUMA platform.

	  Otherwise, you should say N.

config AMD_NUMA
	def_bool y
	prompt "Old style AMD Opteron NUMA detection"
	depends on X86_64 && NUMA && PCI
	---help---
	  Enable AMD NUMA node topology detection.  You should say Y here if
	  you have a multi processor AMD system. This uses an old method to
	  read the NUMA configuration directly from the builtin Northbridge
	  of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
	  which also takes priority if both are compiled in.

config X86_64_ACPI_NUMA
	def_bool y
	prompt "ACPI NUMA detection"
	depends on X86_64 && NUMA && ACPI && PCI
	select ACPI_NUMA
	---help---
	  Enable ACPI SRAT based node topology detection.

# Some NUMA nodes have memory ranges that span
# other nodes.  Even though a pfn is valid and
# between a node's start and end pfns, it may not
# reside on that node.  See memmap_init_zone()
# for details.
config NODES_SPAN_OTHER_NODES
	def_bool y
	depends on X86_64_ACPI_NUMA

config NUMA_EMU
	bool "NUMA emulation"
	depends on NUMA
	---help---
	  Enable NUMA emulation. A flat machine will be split
	  into virtual nodes when booted with "numa=fake=N", where N is the
	  number of nodes. This is only useful for debugging.

config NODES_SHIFT
	int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
	range 1 10
	default "10" if MAXSMP
	default "6" if X86_64
	default "3"
	depends on NEED_MULTIPLE_NODES
	---help---
	  Specify the maximum number of NUMA Nodes available on the target
	  system.  Increases memory reserved to accommodate various tables.

config ARCH_HAVE_MEMORY_PRESENT
	def_bool y
	depends on X86_32 && DISCONTIGMEM

config NEED_NODE_MEMMAP_SIZE
	def_bool y
	depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)

config ARCH_FLATMEM_ENABLE
	def_bool y
	depends on X86_32 && !NUMA

config ARCH_DISCONTIGMEM_ENABLE
	def_bool y
	depends on NUMA && X86_32

config ARCH_DISCONTIGMEM_DEFAULT
	def_bool y
	depends on NUMA && X86_32

config ARCH_SPARSEMEM_ENABLE
	def_bool y
	depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
	select SPARSEMEM_STATIC if X86_32
	select SPARSEMEM_VMEMMAP_ENABLE if X86_64

config ARCH_SPARSEMEM_DEFAULT
	def_bool y
	depends on X86_64

config ARCH_SELECT_MEMORY_MODEL
	def_bool y
	depends on ARCH_SPARSEMEM_ENABLE

config ARCH_MEMORY_PROBE
	bool "Enable sysfs memory/probe interface"
	depends on X86_64 && MEMORY_HOTPLUG
	help
	  This option enables a sysfs memory/probe interface for testing.
	  See Documentation/memory-hotplug.txt for more information.
	  If you are unsure how to answer this question, answer N.

config ARCH_PROC_KCORE_TEXT
	def_bool y
	depends on X86_64 && PROC_KCORE

config ILLEGAL_POINTER_VALUE
       hex
       default 0 if X86_32
       default 0xdead000000000000 if X86_64

source "mm/Kconfig"

config X86_PMEM_LEGACY_DEVICE
	bool

config X86_PMEM_LEGACY
	tristate "Support non-standard NVDIMMs and ADR protected memory"
	depends on PHYS_ADDR_T_64BIT
	depends on BLK_DEV
	select X86_PMEM_LEGACY_DEVICE
	select LIBNVDIMM
	help
	  Treat memory marked using the non-standard e820 type of 12 as used
	  by the Intel Sandy Bridge-EP reference BIOS as protected memory.
	  The kernel will offer these regions to the 'pmem' driver so
	  they can be used for persistent storage.

	  Say Y if unsure.

config HIGHPTE
	bool "Allocate 3rd-level pagetables from highmem"
	depends on HIGHMEM
	---help---
	  The VM uses one page table entry for each page of physical memory.
	  For systems with a lot of RAM, this can be wasteful of precious
	  low memory.  Setting this option will put user-space page table
	  entries in high memory.

config X86_CHECK_BIOS_CORRUPTION
	bool "Check for low memory corruption"
	---help---
	  Periodically check for memory corruption in low memory, which
	  is suspected to be caused by BIOS.  Even when enabled in the
	  configuration, it is disabled at runtime.  Enable it by
	  setting "memory_corruption_check=1" on the kernel command
	  line.  By default it scans the low 64k of memory every 60
	  seconds; see the memory_corruption_check_size and
	  memory_corruption_check_period parameters in
	  Documentation/kernel-parameters.txt to adjust this.

	  When enabled with the default parameters, this option has
	  almost no overhead, as it reserves a relatively small amount
	  of memory and scans it infrequently.  It both detects corruption
	  and prevents it from affecting the running system.

	  It is, however, intended as a diagnostic tool; if repeatable
	  BIOS-originated corruption always affects the same memory,
	  you can use memmap= to prevent the kernel from using that
	  memory.

config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
	bool "Set the default setting of memory_corruption_check"
	depends on X86_CHECK_BIOS_CORRUPTION
	default y
	---help---
	  Set whether the default state of memory_corruption_check is
	  on or off.

config X86_RESERVE_LOW
	int "Amount of low memory, in kilobytes, to reserve for the BIOS"
	default 64
	range 4 640
	---help---
	  Specify the amount of low memory to reserve for the BIOS.

	  The first page contains BIOS data structures that the kernel
	  must not use, so that page must always be reserved.

	  By default we reserve the first 64K of physical RAM, as a
	  number of BIOSes are known to corrupt that memory range
	  during events such as suspend/resume or monitor cable
	  insertion, so it must not be used by the kernel.

	  You can set this to 4 if you are absolutely sure that you
	  trust the BIOS to get all its memory reservations and usages
	  right.  If you know your BIOS have problems beyond the
	  default 64K area, you can set this to 640 to avoid using the
	  entire low memory range.

	  If you have doubts about the BIOS (e.g. suspend/resume does
	  not work or there's kernel crashes after certain hardware
	  hotplug events) then you might want to enable
	  X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
	  typical corruption patterns.

	  Leave this to the default value of 64 if you are unsure.

config MATH_EMULATION
	bool
	depends on MODIFY_LDT_SYSCALL
	prompt "Math emulation" if X86_32
	---help---
	  Linux can emulate a math coprocessor (used for floating point
	  operations) if you don't have one. 486DX and Pentium processors have
	  a math coprocessor built in, 486SX and 386 do not, unless you added
	  a 487DX or 387, respectively. (The messages during boot time can
	  give you some hints here ["man dmesg"].) Everyone needs either a
	  coprocessor or this emulation.

	  If you don't have a math coprocessor, you need to say Y here; if you
	  say Y here even though you have a coprocessor, the coprocessor will
	  be used nevertheless. (This behavior can be changed with the kernel
	  command line option "no387", which comes handy if your coprocessor
	  is broken. Try "man bootparam" or see the documentation of your boot
	  loader (lilo or loadlin) about how to pass options to the kernel at
	  boot time.) This means that it is a good idea to say Y here if you
	  intend to use this kernel on different machines.

	  More information about the internals of the Linux math coprocessor
	  emulation can be found in <file:arch/x86/math-emu/README>.

	  If you are not sure, say Y; apart from resulting in a 66 KB bigger
	  kernel, it won't hurt.

config MTRR
	def_bool y
	prompt "MTRR (Memory Type Range Register) support" if EXPERT
	---help---
	  On Intel P6 family processors (Pentium Pro, Pentium II and later)
	  the Memory Type Range Registers (MTRRs) may be used to control
	  processor access to memory ranges. This is most useful if you have
	  a video (VGA) card on a PCI or AGP bus. Enabling write-combining
	  allows bus write transfers to be combined into a larger transfer
	  before bursting over the PCI/AGP bus. This can increase performance
	  of image write operations 2.5 times or more. Saying Y here creates a
	  /proc/mtrr file which may be used to manipulate your processor's
	  MTRRs. Typically the X server should use this.

	  This code has a reasonably generic interface so that similar
	  control registers on other processors can be easily supported
	  as well:

	  The Cyrix 6x86, 6x86MX and M II processors have Address Range
	  Registers (ARRs) which provide a similar functionality to MTRRs. For
	  these, the ARRs are used to emulate the MTRRs.
	  The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
	  MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
	  write-combining. All of these processors are supported by this code
	  and it makes sense to say Y here if you have one of them.

	  Saying Y here also fixes a problem with buggy SMP BIOSes which only
	  set the MTRRs for the boot CPU and not for the secondary CPUs. This
	  can lead to all sorts of problems, so it's good to say Y here.

	  You can safely say Y even if your machine doesn't have MTRRs, you'll
	  just add about 9 KB to your kernel.

	  See <file:Documentation/x86/mtrr.txt> for more information.

config MTRR_SANITIZER
	def_bool y
	prompt "MTRR cleanup support"
	depends on MTRR
	---help---
	  Convert MTRR layout from continuous to discrete, so X drivers can
	  add writeback entries.

	  Can be disabled with disable_mtrr_cleanup on the kernel command line.
	  The largest mtrr entry size for a continuous block can be set with
	  mtrr_chunk_size.

	  If unsure, say Y.

config MTRR_SANITIZER_ENABLE_DEFAULT
	int "MTRR cleanup enable value (0-1)"
	range 0 1
	default "0"
	depends on MTRR_SANITIZER
	---help---
	  Enable mtrr cleanup default value

config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
	int "MTRR cleanup spare reg num (0-7)"
	range 0 7
	default "1"
	depends on MTRR_SANITIZER
	---help---
	  mtrr cleanup spare entries default, it can be changed via
	  mtrr_spare_reg_nr=N on the kernel command line.

config X86_PAT
	def_bool y
	prompt "x86 PAT support" if EXPERT
	depends on MTRR
	---help---
	  Use PAT attributes to setup page level cache control.

	  PATs are the modern equivalents of MTRRs and are much more
	  flexible than MTRRs.

	  Say N here if you see bootup problems (boot crash, boot hang,
	  spontaneous reboots) or a non-working video driver.

	  If unsure, say Y.

config ARCH_USES_PG_UNCACHED
	def_bool y
	depends on X86_PAT

config ARCH_RANDOM
	def_bool y
	prompt "x86 architectural random number generator" if EXPERT
	---help---
	  Enable the x86 architectural RDRAND instruction
	  (Intel Bull Mountain technology) to generate random numbers.
	  If supported, this is a high bandwidth, cryptographically
	  secure hardware random number generator.

config X86_SMAP
	def_bool y
	prompt "Supervisor Mode Access Prevention" if EXPERT
	---help---
	  Supervisor Mode Access Prevention (SMAP) is a security
	  feature in newer Intel processors.  There is a small
	  performance cost if this enabled and turned on; there is
	  also a small increase in the kernel size if this is enabled.

	  If unsure, say Y.

config X86_INTEL_MPX
	prompt "Intel MPX (Memory Protection Extensions)"
	def_bool n
	depends on CPU_SUP_INTEL
	---help---
	  MPX provides hardware features that can be used in
	  conjunction with compiler-instrumented code to check
	  memory references.  It is designed to detect buffer
	  overflow or underflow bugs.

	  This option enables running applications which are
	  instrumented or otherwise use MPX.  It does not use MPX
	  itself inside the kernel or to protect the kernel
	  against bad memory references.

	  Enabling this option will make the kernel larger:
	  ~8k of kernel text and 36 bytes of data on a 64-bit
	  defconfig.  It adds a long to the 'mm_struct' which
	  will increase the kernel memory overhead of each
	  process and adds some branches to paths used during
	  exec() and munmap().

	  For details, see Documentation/x86/intel_mpx.txt

	  If unsure, say N.

config EFI
	bool "EFI runtime service support"
	depends on ACPI
	select UCS2_STRING
	select EFI_RUNTIME_WRAPPERS
	---help---
	  This enables the kernel to use EFI runtime services that are
	  available (such as the EFI variable services).

	  This option is only useful on systems that have EFI firmware.
	  In addition, you should use the latest ELILO loader available
	  at <http://elilo.sourceforge.net> in order to take advantage
	  of EFI runtime services. However, even with this option, the
	  resultant kernel should continue to boot on existing non-EFI
	  platforms.

config EFI_STUB
       bool "EFI stub support"
       depends on EFI && !X86_USE_3DNOW
       select RELOCATABLE
       ---help---
          This kernel feature allows a bzImage to be loaded directly
	  by EFI firmware without the use of a bootloader.

	  See Documentation/efi-stub.txt for more information.

config EFI_MIXED
	bool "EFI mixed-mode support"
	depends on EFI_STUB && X86_64
	---help---
	   Enabling this feature allows a 64-bit kernel to be booted
	   on a 32-bit firmware, provided that your CPU supports 64-bit
	   mode.

	   Note that it is not possible to boot a mixed-mode enabled
	   kernel via the EFI boot stub - a bootloader that supports
	   the EFI handover protocol must be used.

	   If unsure, say N.

config SECCOMP
	def_bool y
	prompt "Enable seccomp to safely compute untrusted bytecode"
	---help---
	  This kernel feature is useful for number crunching applications
	  that may need to compute untrusted bytecode during their
	  execution. By using pipes or other transports made available to
	  the process as file descriptors supporting the read/write
	  syscalls, it's possible to isolate those applications in
	  their own address space using seccomp. Once seccomp is
	  enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
	  and the task is only allowed to execute a few safe syscalls
	  defined by each seccomp mode.

	  If unsure, say Y. Only embedded should say N here.

source kernel/Kconfig.hz

config KEXEC
	bool "kexec system call"
	select KEXEC_CORE
	---help---
	  kexec is a system call that implements the ability to shutdown your
	  current kernel, and to start another kernel.  It is like a reboot
	  but it is independent of the system firmware.   And like a reboot
	  you can start any kernel with it, not just Linux.

	  The name comes from the similarity to the exec system call.

	  It is an ongoing process to be certain the hardware in a machine
	  is properly shutdown, so do not be surprised if this code does not
	  initially work for you.  As of this writing the exact hardware
	  interface is strongly in flux, so no good recommendation can be
	  made.

config KEXEC_FILE
	bool "kexec file based system call"
	select KEXEC_CORE
	select BUILD_BIN2C
	depends on X86_64
	depends on CRYPTO=y
	depends on CRYPTO_SHA256=y
	---help---
	  This is new version of kexec system call. This system call is
	  file based and takes file descriptors as system call argument
	  for kernel and initramfs as opposed to list of segments as
	  accepted by previous system call.

config KEXEC_VERIFY_SIG
	bool "Verify kernel signature during kexec_file_load() syscall"
	depends on KEXEC_FILE
	---help---
	  This option makes kernel signature verification mandatory for
	  the kexec_file_load() syscall.

	  In addition to that option, you need to enable signature
	  verification for the corresponding kernel image type being
	  loaded in order for this to work.

config KEXEC_BZIMAGE_VERIFY_SIG
	bool "Enable bzImage signature verification support"
	depends on KEXEC_VERIFY_SIG
	depends on SIGNED_PE_FILE_VERIFICATION
	select SYSTEM_TRUSTED_KEYRING
	---help---
	  Enable bzImage signature verification support.

config CRASH_DUMP
	bool "kernel crash dumps"
	depends on X86_64 || (X86_32 && HIGHMEM)
	---help---
	  Generate crash dump after being started by kexec.
	  This should be normally only set in special crash dump kernels
	  which are loaded in the main kernel with kexec-tools into
	  a specially reserved region and then later executed after
	  a crash by kdump/kexec. The crash dump kernel must be compiled
	  to a memory address not used by the main kernel or BIOS using
	  PHYSICAL_START, or it must be built as a relocatable image
	  (CONFIG_RELOCATABLE=y).
	  For more details see Documentation/kdump/kdump.txt

config KEXEC_JUMP
	bool "kexec jump"
	depends on KEXEC && HIBERNATION
	---help---
	  Jump between original kernel and kexeced kernel and invoke
	  code in physical address mode via KEXEC

config PHYSICAL_START
	hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
	default "0x1000000"
	---help---
	  This gives the physical address where the kernel is loaded.

	  If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
	  bzImage will decompress itself to above physical address and
	  run from there. Otherwise, bzImage will run from the address where
	  it has been loaded by the boot loader and will ignore above physical
	  address.

	  In normal kdump cases one does not have to set/change this option
	  as now bzImage can be compiled as a completely relocatable image
	  (CONFIG_RELOCATABLE=y) and be used to load and run from a different
	  address. This option is mainly useful for the folks who don't want
	  to use a bzImage for capturing the crash dump and want to use a
	  vmlinux instead. vmlinux is not relocatable hence a kernel needs
	  to be specifically compiled to run from a specific memory area
	  (normally a reserved region) and this option comes handy.

	  So if you are using bzImage for capturing the crash dump,
	  leave the value here unchanged to 0x1000000 and set
	  CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
	  for capturing the crash dump change this value to start of
	  the reserved region.  In other words, it can be set based on
	  the "X" value as specified in the "crashkernel=YM@XM"
	  command line boot parameter passed to the panic-ed
	  kernel. Please take a look at Documentation/kdump/kdump.txt
	  for more details about crash dumps.

	  Usage of bzImage for capturing the crash dump is recommended as
	  one does not have to build two kernels. Same kernel can be used
	  as production kernel and capture kernel. Above option should have
	  gone away after relocatable bzImage support is introduced. But it
	  is present because there are users out there who continue to use
	  vmlinux for dump capture. This option should go away down the
	  line.

	  Don't change this unless you know what you are doing.

config RELOCATABLE
	bool "Build a relocatable kernel"
	default y
	---help---
	  This builds a kernel image that retains relocation information
	  so it can be loaded someplace besides the default 1MB.
	  The relocations tend to make the kernel binary about 10% larger,
	  but are discarded at runtime.

	  One use is for the kexec on panic case where the recovery kernel
	  must live at a different physical address than the primary
	  kernel.

	  Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
	  it has been loaded at and the compile time physical address
	  (CONFIG_PHYSICAL_START) is used as the minimum location.

config RANDOMIZE_BASE
	bool "Randomize the address of the kernel image"
	depends on RELOCATABLE
	default n
	---help---
	   Randomizes the physical and virtual address at which the
	   kernel image is decompressed, as a security feature that
	   deters exploit attempts relying on knowledge of the location
	   of kernel internals.

	   Entropy is generated using the RDRAND instruction if it is
	   supported. If RDTSC is supported, it is used as well. If
	   neither RDRAND nor RDTSC are supported, then randomness is
	   read from the i8254 timer.

	   The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
	   and aligned according to PHYSICAL_ALIGN. Since the kernel is
	   built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
	   minimum of 2MiB, only 10 bits of entropy is theoretically
	   possible. At best, due to page table layouts, 64-bit can use
	   9 bits of entropy and 32-bit uses 8 bits.

	   If unsure, say N.

config RANDOMIZE_BASE_MAX_OFFSET
	hex "Maximum kASLR offset allowed" if EXPERT
	depends on RANDOMIZE_BASE
	range 0x0 0x20000000 if X86_32
	default "0x20000000" if X86_32
	range 0x0 0x40000000 if X86_64
	default "0x40000000" if X86_64
	---help---
	  The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
	  memory is used to determine the maximal offset in bytes that will
	  be applied to the kernel when kernel Address Space Layout
	  Randomization (kASLR) is active. This must be a multiple of
	  PHYSICAL_ALIGN.

	  On 32-bit this is limited to 512MiB by page table layouts. The
	  default is 512MiB.

	  On 64-bit this is limited by how the kernel fixmap page table is
	  positioned, so this cannot be larger than 1GiB currently. Without
	  RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
	  and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
	  modules area will shrink to compensate, up to the current maximum
	  1GiB to 1GiB split. The default is 1GiB.

	  If unsure, leave at the default value.

# Relocation on x86 needs some additional build support
config X86_NEED_RELOCS
	def_bool y
	depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)

config PHYSICAL_ALIGN
	hex "Alignment value to which kernel should be aligned"
	default "0x200000"
	range 0x2000 0x1000000 if X86_32
	range 0x200000 0x1000000 if X86_64
	---help---
	  This value puts the alignment restrictions on physical address
	  where kernel is loaded and run from. Kernel is compiled for an
	  address which meets above alignment restriction.

	  If bootloader loads the kernel at a non-aligned address and
	  CONFIG_RELOCATABLE is set, kernel will move itself to nearest
	  address aligned to above value and run from there.

	  If bootloader loads the kernel at a non-aligned address and
	  CONFIG_RELOCATABLE is not set, kernel will ignore the run time
	  load address and decompress itself to the address it has been
	  compiled for and run from there. The address for which kernel is
	  compiled already meets above alignment restrictions. Hence the
	  end result is that kernel runs from a physical address meeting
	  above alignment restrictions.

	  On 32-bit this value must be a multiple of 0x2000. On 64-bit
	  this value must be a multiple of 0x200000.

	  Don't change this unless you know what you are doing.

config HOTPLUG_CPU
	bool "Support for hot-pluggable CPUs"
	depends on SMP
	---help---
	  Say Y here to allow turning CPUs off and on. CPUs can be
	  controlled through /sys/devices/system/cpu.
	  ( Note: power management support will enable this option
	    automatically on SMP systems. )
	  Say N if you want to disable CPU hotplug.

config BOOTPARAM_HOTPLUG_CPU0
	bool "Set default setting of cpu0_hotpluggable"
	default n
	depends on HOTPLUG_CPU
	---help---
	  Set whether default state of cpu0_hotpluggable is on or off.

	  Say Y here to enable CPU0 hotplug by default. If this switch
	  is turned on, there is no need to give cpu0_hotplug kernel
	  parameter and the CPU0 hotplug feature is enabled by default.

	  Please note: there are two known CPU0 dependencies if you want
	  to enable the CPU0 hotplug feature either by this switch or by
	  cpu0_hotplug kernel parameter.

	  First, resume from hibernate or suspend always starts from CPU0.
	  So hibernate and suspend are prevented if CPU0 is offline.

	  Second dependency is PIC interrupts always go to CPU0. CPU0 can not
	  offline if any interrupt can not migrate out of CPU0. There may
	  be other CPU0 dependencies.

	  Please make sure the dependencies are under your control before
	  you enable this feature.

	  Say N if you don't want to enable CPU0 hotplug feature by default.
	  You still can enable the CPU0 hotplug feature at boot by kernel
	  parameter cpu0_hotplug.

config DEBUG_HOTPLUG_CPU0
	def_bool n
	prompt "Debug CPU0 hotplug"
	depends on HOTPLUG_CPU
	---help---
	  Enabling this option offlines CPU0 (if CPU0 can be offlined) as
	  soon as possible and boots up userspace with CPU0 offlined. User
	  can online CPU0 back after boot time.

	  To debug CPU0 hotplug, you need to enable CPU0 offline/online
	  feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
	  compilation or giving cpu0_hotplug kernel parameter at boot.

	  If unsure, say N.

config COMPAT_VDSO
	def_bool n
	prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
	depends on X86_32 || IA32_EMULATION
	---help---
	  Certain buggy versions of glibc will crash if they are
	  presented with a 32-bit vDSO that is not mapped at the address
	  indicated in its segment table.

	  The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
	  and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
	  49ad572a70b8aeb91e57483a11dd1b77e31c4468.  Glibc 2.3.3 is
	  the only released version with the bug, but OpenSUSE 9
	  contains a buggy "glibc 2.3.2".

	  The symptom of the bug is that everything crashes on startup, saying:
	  dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!

	  Saying Y here changes the default value of the vdso32 boot
	  option from 1 to 0, which turns off the 32-bit vDSO entirely.
	  This works around the glibc bug but hurts performance.

	  If unsure, say N: if you are compiling your own kernel, you
	  are unlikely to be using a buggy version of glibc.

choice
	prompt "vsyscall table for legacy applications"
	depends on X86_64
	default LEGACY_VSYSCALL_EMULATE
	help
	  Legacy user code that does not know how to find the vDSO expects
	  to be able to issue three syscalls by calling fixed addresses in
	  kernel space. Since this location is not randomized with ASLR,
	  it can be used to assist security vulnerability exploitation.

	  This setting can be changed at boot time via the kernel command
	  line parameter vsyscall=[native|emulate|none].

	  On a system with recent enough glibc (2.14 or newer) and no
	  static binaries, you can say None without a performance penalty
	  to improve security.

	  If unsure, select "Emulate".

	config LEGACY_VSYSCALL_NATIVE
		bool "Native"
		help
		  Actual executable code is located in the fixed vsyscall
		  address mapping, implementing time() efficiently. Since
		  this makes the mapping executable, it can be used during
		  security vulnerability exploitation (traditionally as
		  ROP gadgets). This configuration is not recommended.

	config LEGACY_VSYSCALL_EMULATE
		bool "Emulate"
		help
		  The kernel traps and emulates calls into the fixed
		  vsyscall address mapping. This makes the mapping
		  non-executable, but it still contains known contents,
		  which could be used in certain rare security vulnerability
		  exploits. This configuration is recommended when userspace
		  still uses the vsyscall area.

	config LEGACY_VSYSCALL_NONE
		bool "None"
		help
		  There will be no vsyscall mapping at all. This will
		  eliminate any risk of ASLR bypass due to the vsyscall
		  fixed address mapping. Attempts to use the vsyscalls
		  will be reported to dmesg, so that either old or
		  malicious userspace programs can be identified.

endchoice

config CMDLINE_BOOL
	bool "Built-in kernel command line"
	---help---
	  Allow for specifying boot arguments to the kernel at
	  build time.  On some systems (e.g. embedded ones), it is
	  necessary or convenient to provide some or all of the
	  kernel boot arguments with the kernel itself (that is,
	  to not rely on the boot loader to provide them.)

	  To compile command line arguments into the kernel,
	  set this option to 'Y', then fill in the
	  boot arguments in CONFIG_CMDLINE.

	  Systems with fully functional boot loaders (i.e. non-embedded)
	  should leave this option set to 'N'.

config CMDLINE
	string "Built-in kernel command string"
	depends on CMDLINE_BOOL
	default ""
	---help---
	  Enter arguments here that should be compiled into the kernel
	  image and used at boot time.  If the boot loader provides a
	  command line at boot time, it is appended to this string to
	  form the full kernel command line, when the system boots.

	  However, you can use the CONFIG_CMDLINE_OVERRIDE option to
	  change this behavior.

	  In most cases, the command line (whether built-in or provided
	  by the boot loader) should specify the device for the root
	  file system.

config CMDLINE_OVERRIDE
	bool "Built-in command line overrides boot loader arguments"
	depends on CMDLINE_BOOL
	---help---
	  Set this option to 'Y' to have the kernel ignore the boot loader
	  command line, and use ONLY the built-in command line.

	  This is used to work around broken boot loaders.  This should
	  be set to 'N' under normal conditions.

config MODIFY_LDT_SYSCALL
	bool "Enable the LDT (local descriptor table)" if EXPERT
	default y
	---help---
	  Linux can allow user programs to install a per-process x86
	  Local Descriptor Table (LDT) using the modify_ldt(2) system
	  call.  This is required to run 16-bit or segmented code such as
	  DOSEMU or some Wine programs.  It is also used by some very old
	  threading libraries.

	  Enabling this feature adds a small amount of overhead to
	  context switches and increases the low-level kernel attack
	  surface.  Disabling it removes the modify_ldt(2) system call.

	  Saying 'N' here may make sense for embedded or server kernels.

source "kernel/livepatch/Kconfig"

endmenu

config ARCH_ENABLE_MEMORY_HOTPLUG
	def_bool y
	depends on X86_64 || (X86_32 && HIGHMEM)

config ARCH_ENABLE_MEMORY_HOTREMOVE
	def_bool y
	depends on MEMORY_HOTPLUG

config USE_PERCPU_NUMA_NODE_ID
	def_bool y
	depends on NUMA

config ARCH_ENABLE_SPLIT_PMD_PTLOCK
	def_bool y
	depends on X86_64 || X86_PAE

config ARCH_ENABLE_HUGEPAGE_MIGRATION
	def_bool y
	depends on X86_64 && HUGETLB_PAGE && MIGRATION

menu "Power management and ACPI options"

config ARCH_HIBERNATION_HEADER
	def_bool y
	depends on X86_64 && HIBERNATION

source "kernel/power/Kconfig"

source "drivers/acpi/Kconfig"

source "drivers/sfi/Kconfig"

config X86_APM_BOOT
	def_bool y
	depends on APM

menuconfig APM
	tristate "APM (Advanced Power Management) BIOS support"
	depends on X86_32 && PM_SLEEP
	---help---
	  APM is a BIOS specification for saving power using several different
	  techniques. This is mostly useful for battery powered laptops with
	  APM compliant BIOSes. If you say Y here, the system time will be
	  reset after a RESUME operation, the /proc/apm device will provide
	  battery status information, and user-space programs will receive
	  notification of APM "events" (e.g. battery status change).

	  If you select "Y" here, you can disable actual use of the APM
	  BIOS by passing the "apm=off" option to the kernel at boot time.

	  Note that the APM support is almost completely disabled for
	  machines with more than one CPU.

	  In order to use APM, you will need supporting software. For location
	  and more information, read <file:Documentation/power/apm-acpi.txt>
	  and the Battery Powered Linux mini-HOWTO, available from
	  <http://www.tldp.org/docs.html#howto>.

	  This driver does not spin down disk drives (see the hdparm(8)
	  manpage ("man 8 hdparm") for that), and it doesn't turn off
	  VESA-compliant "green" monitors.

	  This driver does not support the TI 4000M TravelMate and the ACER
	  486/DX4/75 because they don't have compliant BIOSes. Many "green"
	  desktop machines also don't have compliant BIOSes, and this driver
	  may cause those machines to panic during the boot phase.

	  Generally, if you don't have a battery in your machine, there isn't
	  much point in using this driver and you should say N. If you get
	  random kernel OOPSes or reboots that don't seem to be related to
	  anything, try disabling/enabling this option (or disabling/enabling
	  APM in your BIOS).

	  Some other things you should try when experiencing seemingly random,
	  "weird" problems:

	  1) make sure that you have enough swap space and that it is
	  enabled.
	  2) pass the "no-hlt" option to the kernel
	  3) switch on floating point emulation in the kernel and pass
	  the "no387" option to the kernel
	  4) pass the "floppy=nodma" option to the kernel
	  5) pass the "mem=4M" option to the kernel (thereby disabling
	  all but the first 4 MB of RAM)
	  6) make sure that the CPU is not over clocked.
	  7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
	  8) disable the cache from your BIOS settings
	  9) install a fan for the video card or exchange video RAM
	  10) install a better fan for the CPU
	  11) exchange RAM chips
	  12) exchange the motherboard.

	  To compile this driver as a module, choose M here: the
	  module will be called apm.

if APM

config APM_IGNORE_USER_SUSPEND
	bool "Ignore USER SUSPEND"
	---help---
	  This option will ignore USER SUSPEND requests. On machines with a
	  compliant APM BIOS, you want to say N. However, on the NEC Versa M
	  series notebooks, it is necessary to say Y because of a BIOS bug.

config APM_DO_ENABLE
	bool "Enable PM at boot time"
	---help---
	  Enable APM features at boot time. From page 36 of the APM BIOS
	  specification: "When disabled, the APM BIOS does not automatically
	  power manage devices, enter the Standby State, enter the Suspend
	  State, or take power saving steps in response to CPU Idle calls."
	  This driver will make CPU Idle calls when Linux is idle (unless this
	  feature is turned off -- see "Do CPU IDLE calls", below). This
	  should always save battery power, but more complicated APM features
	  will be dependent on your BIOS implementation. You may need to turn
	  this option off if your computer hangs at boot time when using APM
	  support, or if it beeps continuously instead of suspending. Turn
	  this off if you have a NEC UltraLite Versa 33/C or a Toshiba
	  T400CDT. This is off by default since most machines do fine without
	  this feature.

config APM_CPU_IDLE
	depends on CPU_IDLE
	bool "Make CPU Idle calls when idle"
	---help---
	  Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
	  On some machines, this can activate improved power savings, such as
	  a slowed CPU clock rate, when the machine is idle. These idle calls
	  are made after the idle loop has run for some length of time (e.g.,
	  333 mS). On some machines, this will cause a hang at boot time or
	  whenever the CPU becomes idle. (On machines with more than one CPU,
	  this option does nothing.)

config APM_DISPLAY_BLANK
	bool "Enable console blanking using APM"
	---help---
	  Enable console blanking using the APM. Some laptops can use this to
	  turn off the LCD backlight when the screen blanker of the Linux
	  virtual console blanks the screen. Note that this is only used by
	  the virtual console screen blanker, and won't turn off the backlight
	  when using the X Window system. This also doesn't have anything to
	  do with your VESA-compliant power-saving monitor. Further, this
	  option doesn't work for all laptops -- it might not turn off your
	  backlight at all, or it might print a lot of errors to the console,
	  especially if you are using gpm.

config APM_ALLOW_INTS
	bool "Allow interrupts during APM BIOS calls"
	---help---
	  Normally we disable external interrupts while we are making calls to
	  the APM BIOS as a measure to lessen the effects of a badly behaving
	  BIOS implementation.  The BIOS should reenable interrupts if it
	  needs to.  Unfortunately, some BIOSes do not -- especially those in
	  many of the newer IBM Thinkpads.  If you experience hangs when you
	  suspend, try setting this to Y.  Otherwise, say N.

endif # APM

source "drivers/cpufreq/Kconfig"

source "drivers/cpuidle/Kconfig"

source "drivers/idle/Kconfig"

endmenu


menu "Bus options (PCI etc.)"

config PCI
	bool "PCI support"
	default y
	---help---
	  Find out whether you have a PCI motherboard. PCI is the name of a
	  bus system, i.e. the way the CPU talks to the other stuff inside
	  your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
	  VESA. If you have PCI, say Y, otherwise N.

choice
	prompt "PCI access mode"
	depends on X86_32 && PCI
	default PCI_GOANY
	---help---
	  On PCI systems, the BIOS can be used to detect the PCI devices and
	  determine their configuration. However, some old PCI motherboards
	  have BIOS bugs and may crash if this is done. Also, some embedded
	  PCI-based systems don't have any BIOS at all. Linux can also try to
	  detect the PCI hardware directly without using the BIOS.

	  With this option, you can specify how Linux should detect the
	  PCI devices. If you choose "BIOS", the BIOS will be used,
	  if you choose "Direct", the BIOS won't be used, and if you
	  choose "MMConfig", then PCI Express MMCONFIG will be used.
	  If you choose "Any", the kernel will try MMCONFIG, then the
	  direct access method and falls back to the BIOS if that doesn't
	  work. If unsure, go with the default, which is "Any".

config PCI_GOBIOS
	bool "BIOS"

config PCI_GOMMCONFIG
	bool "MMConfig"

config PCI_GODIRECT
	bool "Direct"

config PCI_GOOLPC
	bool "OLPC XO-1"
	depends on OLPC

config PCI_GOANY
	bool "Any"

endchoice

config PCI_BIOS
	def_bool y
	depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)

# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
config PCI_DIRECT
	def_bool y
	depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))

config PCI_MMCONFIG
	def_bool y
	depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)

config PCI_OLPC
	def_bool y
	depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)

config PCI_XEN
	def_bool y
	depends on PCI && XEN
	select SWIOTLB_XEN

config PCI_DOMAINS
	def_bool y
	depends on PCI

config PCI_MMCONFIG
	bool "Support mmconfig PCI config space access"
	depends on X86_64 && PCI && ACPI

config PCI_CNB20LE_QUIRK
	bool "Read CNB20LE Host Bridge Windows" if EXPERT
	depends on PCI
	help
	  Read the PCI windows out of the CNB20LE host bridge. This allows
	  PCI hotplug to work on systems with the CNB20LE chipset which do
	  not have ACPI.

	  There's no public spec for this chipset, and this functionality
	  is known to be incomplete.

	  You should say N unless you know you need this.

source "drivers/pci/pcie/Kconfig"

source "drivers/pci/Kconfig"

# x86_64 have no ISA slots, but can have ISA-style DMA.
config ISA_DMA_API
	bool "ISA-style DMA support" if (X86_64 && EXPERT)
	default y
	help
	  Enables ISA-style DMA support for devices requiring such controllers.
	  If unsure, say Y.

if X86_32

config ISA
	bool "ISA support"
	---help---
	  Find out whether you have ISA slots on your motherboard.  ISA is the
	  name of a bus system, i.e. the way the CPU talks to the other stuff
	  inside your box.  Other bus systems are PCI, EISA, MicroChannel
	  (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
	  newer boards don't support it.  If you have ISA, say Y, otherwise N.

config EISA
	bool "EISA support"
	depends on ISA
	---help---
	  The Extended Industry Standard Architecture (EISA) bus was
	  developed as an open alternative to the IBM MicroChannel bus.

	  The EISA bus provided some of the features of the IBM MicroChannel
	  bus while maintaining backward compatibility with cards made for
	  the older ISA bus.  The EISA bus saw limited use between 1988 and
	  1995 when it was made obsolete by the PCI bus.

	  Say Y here if you are building a kernel for an EISA-based machine.

	  Otherwise, say N.

source "drivers/eisa/Kconfig"

config SCx200
	tristate "NatSemi SCx200 support"
	---help---
	  This provides basic support for National Semiconductor's
	  (now AMD's) Geode processors.  The driver probes for the
	  PCI-IDs of several on-chip devices, so its a good dependency
	  for other scx200_* drivers.

	  If compiled as a module, the driver is named scx200.

config SCx200HR_TIMER
	tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
	depends on SCx200
	default y
	---help---
	  This driver provides a clocksource built upon the on-chip
	  27MHz high-resolution timer.  Its also a workaround for
	  NSC Geode SC-1100's buggy TSC, which loses time when the
	  processor goes idle (as is done by the scheduler).  The
	  other workaround is idle=poll boot option.

config OLPC
	bool "One Laptop Per Child support"
	depends on !X86_PAE
	select GPIOLIB
	select OF
	select OF_PROMTREE
	select IRQ_DOMAIN
	---help---
	  Add support for detecting the unique features of the OLPC
	  XO hardware.

config OLPC_XO1_PM
	bool "OLPC XO-1 Power Management"
	depends on OLPC && MFD_CS5535 && PM_SLEEP
	select MFD_CORE
	---help---
	  Add support for poweroff and suspend of the OLPC XO-1 laptop.

config OLPC_XO1_RTC
	bool "OLPC XO-1 Real Time Clock"
	depends on OLPC_XO1_PM && RTC_DRV_CMOS
	---help---
	  Add support for the XO-1 real time clock, which can be used as a
	  programmable wakeup source.

config OLPC_XO1_SCI
	bool "OLPC XO-1 SCI extras"
	depends on OLPC && OLPC_XO1_PM
	depends on INPUT=y
	select POWER_SUPPLY
	select GPIO_CS5535
	select MFD_CORE
	---help---
	  Add support for SCI-based features of the OLPC XO-1 laptop:
	   - EC-driven system wakeups
	   - Power button
	   - Ebook switch
	   - Lid switch
	   - AC adapter status updates
	   - Battery status updates

config OLPC_XO15_SCI
	bool "OLPC XO-1.5 SCI extras"
	depends on OLPC && ACPI
	select POWER_SUPPLY
	---help---
	  Add support for SCI-based features of the OLPC XO-1.5 laptop:
	   - EC-driven system wakeups
	   - AC adapter status updates
	   - Battery status updates

config ALIX
	bool "PCEngines ALIX System Support (LED setup)"
	select GPIOLIB
	---help---
	  This option enables system support for the PCEngines ALIX.
	  At present this just sets up LEDs for GPIO control on
	  ALIX2/3/6 boards.  However, other system specific setup should
	  get added here.

	  Note: You must still enable the drivers for GPIO and LED support
	  (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs

	  Note: You have to set alix.force=1 for boards with Award BIOS.

config NET5501
	bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
	select GPIOLIB
	---help---
	  This option enables system support for the Soekris Engineering net5501.

config GEOS
	bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
	select GPIOLIB
	depends on DMI
	---help---
	  This option enables system support for the Traverse Technologies GEOS.

config TS5500
	bool "Technologic Systems TS-5500 platform support"
	depends on MELAN
	select CHECK_SIGNATURE
	select NEW_LEDS
	select LEDS_CLASS
	---help---
	  This option enables system support for the Technologic Systems TS-5500.

endif # X86_32

config AMD_NB
	def_bool y
	depends on CPU_SUP_AMD && PCI

source "drivers/pcmcia/Kconfig"

source "drivers/pci/hotplug/Kconfig"

config RAPIDIO
	tristate "RapidIO support"
	depends on PCI
	default n
	help
	  If enabled this option will include drivers and the core
	  infrastructure code to support RapidIO interconnect devices.

source "drivers/rapidio/Kconfig"

config X86_SYSFB
	bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
	help
	  Firmwares often provide initial graphics framebuffers so the BIOS,
	  bootloader or kernel can show basic video-output during boot for
	  user-guidance and debugging. Historically, x86 used the VESA BIOS
	  Extensions and EFI-framebuffers for this, which are mostly limited
	  to x86.
	  This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
	  framebuffers so the new generic system-framebuffer drivers can be
	  used on x86. If the framebuffer is not compatible with the generic
	  modes, it is adverticed as fallback platform framebuffer so legacy
	  drivers like efifb, vesafb and uvesafb can pick it up.
	  If this option is not selected, all system framebuffers are always
	  marked as fallback platform framebuffers as usual.

	  Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
	  not be able to pick up generic system framebuffers if this option
	  is selected. You are highly encouraged to enable simplefb as
	  replacement if you select this option. simplefb can correctly deal
	  with generic system framebuffers. But you should still keep vesafb
	  and others enabled as fallback if a system framebuffer is
	  incompatible with simplefb.

	  If unsure, say Y.

endmenu


menu "Executable file formats / Emulations"

source "fs/Kconfig.binfmt"

config IA32_EMULATION
	bool "IA32 Emulation"
	depends on X86_64
	select BINFMT_ELF
	select COMPAT_BINFMT_ELF
	select ARCH_WANT_OLD_COMPAT_IPC
	---help---
	  Include code to run legacy 32-bit programs under a
	  64-bit kernel. You should likely turn this on, unless you're
	  100% sure that you don't have any 32-bit programs left.

config IA32_AOUT
	tristate "IA32 a.out support"
	depends on IA32_EMULATION
	---help---
	  Support old a.out binaries in the 32bit emulation.

config X86_X32
	bool "x32 ABI for 64-bit mode"
	depends on X86_64
	---help---
	  Include code to run binaries for the x32 native 32-bit ABI
	  for 64-bit processors.  An x32 process gets access to the
	  full 64-bit register file and wide data path while leaving
	  pointers at 32 bits for smaller memory footprint.

	  You will need a recent binutils (2.22 or later) with
	  elf32_x86_64 support enabled to compile a kernel with this
	  option set.

config COMPAT
	def_bool y
	depends on IA32_EMULATION || X86_X32

if COMPAT
config COMPAT_FOR_U64_ALIGNMENT
	def_bool y

config SYSVIPC_COMPAT
	def_bool y
	depends on SYSVIPC

config KEYS_COMPAT
	def_bool y
	depends on KEYS
endif

endmenu


config HAVE_ATOMIC_IOMAP
	def_bool y
	depends on X86_32

config X86_DEV_DMA_OPS
	bool
	depends on X86_64 || STA2X11

config X86_DMA_REMAP
	bool
	depends on STA2X11

config PMC_ATOM
	def_bool y
        depends on PCI

source "net/Kconfig"

source "drivers/Kconfig"

source "drivers/firmware/Kconfig"

source "fs/Kconfig"

source "arch/x86/Kconfig.debug"

source "security/Kconfig"

source "crypto/Kconfig"

source "arch/x86/kvm/Kconfig"

source "lib/Kconfig"