arch/x86/Kconfig

# x86 configuration
mainmenu "Linux Kernel Configuration for x86"

# Select 32 or 64 bit
config 64BIT
	bool "64-bit kernel" if ARCH = "x86"
	default ARCH = "x86_64"
	---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 !64BIT

config X86_64
	def_bool 64BIT

### Arch settings
config X86
	def_bool y
	select HAVE_AOUT if X86_32
	select HAVE_READQ
	select HAVE_WRITEQ
	select HAVE_UNSTABLE_SCHED_CLOCK
	select HAVE_IDE
	select HAVE_OPROFILE
	select HAVE_IOREMAP_PROT
	select HAVE_KPROBES
	select ARCH_WANT_OPTIONAL_GPIOLIB
	select ARCH_WANT_FRAME_POINTERS
	select HAVE_KRETPROBES
	select HAVE_FTRACE_MCOUNT_RECORD
	select HAVE_DYNAMIC_FTRACE
	select HAVE_FUNCTION_TRACER
	select HAVE_FUNCTION_GRAPH_TRACER
	select HAVE_FUNCTION_TRACE_MCOUNT_TEST
	select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
	select HAVE_FTRACE_SYSCALLS
	select HAVE_KVM
	select HAVE_ARCH_KGDB
	select HAVE_ARCH_TRACEHOOK
	select HAVE_GENERIC_DMA_COHERENT if X86_32
	select HAVE_EFFICIENT_UNALIGNED_ACCESS
	select USER_STACKTRACE_SUPPORT
	select HAVE_DMA_API_DEBUG
	select HAVE_KERNEL_GZIP
	select HAVE_KERNEL_BZIP2
	select HAVE_KERNEL_LZMA

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

config GENERIC_TIME
	def_bool y

config GENERIC_CMOS_UPDATE
	def_bool y

config CLOCKSOURCE_WATCHDOG
	def_bool y

config GENERIC_CLOCKEVENTS
	def_bool y

config GENERIC_CLOCKEVENTS_BROADCAST
	def_bool y
	depends on X86_64 || (X86_32 && X86_LOCAL_APIC)

config LOCKDEP_SUPPORT
	def_bool y

config STACKTRACE_SUPPORT
	def_bool y

config HAVE_LATENCYTOP_SUPPORT
	def_bool y

config FAST_CMPXCHG_LOCAL
	bool
	default y

config MMU
	def_bool y

config ZONE_DMA
	def_bool y

config SBUS
	bool

config GENERIC_ISA_DMA
	def_bool y

config GENERIC_IOMAP
	def_bool y

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 GENERIC_GPIO
	bool

config ARCH_MAY_HAVE_PC_FDC
	def_bool y

config RWSEM_GENERIC_SPINLOCK
	def_bool !X86_XADD

config RWSEM_XCHGADD_ALGORITHM
	def_bool X86_XADD

config ARCH_HAS_CPU_IDLE_WAIT
	def_bool y

config GENERIC_CALIBRATE_DELAY
	def_bool y

config GENERIC_TIME_VSYSCALL
	bool
	default X86_64

config ARCH_HAS_CPU_RELAX
	def_bool y

config ARCH_HAS_DEFAULT_IDLE
	def_bool y

config ARCH_HAS_CACHE_LINE_SIZE
	def_bool y

config HAVE_SETUP_PER_CPU_AREA
	def_bool y

config HAVE_DYNAMIC_PER_CPU_AREA
	def_bool y

config HAVE_CPUMASK_OF_CPU_MAP
	def_bool X86_64_SMP

config ARCH_HIBERNATION_POSSIBLE
	def_bool y

config ARCH_SUSPEND_POSSIBLE
	def_bool y

config ZONE_DMA32
	bool
	default X86_64

config ARCH_POPULATES_NODE_MAP
	def_bool y

config AUDIT_ARCH
	bool
	default X86_64

config ARCH_SUPPORTS_OPTIMIZED_INLINING
	def_bool y

config ARCH_SUPPORTS_DEBUG_PAGEALLOC
	def_bool y

# Use the generic interrupt handling code in kernel/irq/:
config GENERIC_HARDIRQS
	bool
	default y

config GENERIC_HARDIRQS_NO__DO_IRQ
       def_bool y

config GENERIC_IRQ_PROBE
	bool
	default y

config GENERIC_PENDING_IRQ
	bool
	depends on GENERIC_HARDIRQS && SMP
	default y

config USE_GENERIC_SMP_HELPERS
	def_bool y
	depends on SMP

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_HT
	bool
	depends on SMP
	default y

config X86_TRAMPOLINE
	bool
	depends on SMP || (64BIT && ACPI_SLEEP)
	default y

config X86_32_LAZY_GS
	def_bool y
	depends on X86_32 && !CC_STACKPROTECTOR

config KTIME_SCALAR
	def_bool X86_32
source "init/Kconfig"
source "kernel/Kconfig.freezer"

menu "Processor type and features"

source "kernel/time/Kconfig"

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, like most personal computers, say N. If
	  you have a system with more than one CPU, say Y.

	  If you say N here, the kernel will run on single 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,
	  singleprocessor machines. On a singleprocessor 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/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_X2APIC
	bool "Support x2apic"
	depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
	---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 SPARSE_IRQ
	bool "Support sparse irq numbering"
	depends on PCI_MSI || HT_IRQ
	---help---
	  This enables support for sparse irqs. This is useful for distro
	  kernels that want to define a high CONFIG_NR_CPUS value but still
	  want to have low kernel memory footprint on smaller machines.

	  ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
	    out the irq_desc[] array in a more NUMA-friendly way. )

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

config X86_MPPARSE
	bool "Enable MPS table" if ACPI
	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

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:
		AMD Elan
		NUMAQ (IBM/Sequent)
		RDC R-321x SoC
		SGI 320/540 (Visual Workstation)
		Summit/EXA (IBM x440)
		Unisys ES7000 IA32 series

	  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:
		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_VSMP
	bool "ScaleMP vSMP"
	select PARAVIRT
	depends on X86_64 && PCI
	depends on X86_EXTENDED_PLATFORM
	---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
	select X86_X2APIC
	---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_ELAN
	bool "AMD Elan"
	depends on X86_32
	depends on X86_EXTENDED_PLATFORM
	---help---
	  Select this for an AMD Elan processor.

	  Do not use this option for K6/Athlon/Opteron processors!

	  If unsure, choose "PC-compatible" instead.

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 NUMAQ, Summit, bigsmp, ES7000, 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_NUMAQ
	bool "NUMAQ (IBM/Sequent)"
	depends on X86_32_NON_STANDARD
	select NUMA
	select X86_MPPARSE
	---help---
	  This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
	  NUMA multiquad box. This changes the way that processors are
	  bootstrapped, and uses Clustered Logical APIC addressing mode instead
	  of Flat Logical.  You will need a new lynxer.elf file to flash your
	  firmware with - send email to <Martin.Bligh@us.ibm.com>.

config X86_VISWS
	bool "SGI 320/540 (Visual Workstation)"
	depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
	depends on X86_32_NON_STANDARD
	---help---
	  The SGI Visual Workstation series is an IA32-based workstation
	  based on SGI systems chips with some legacy PC hardware attached.

	  Say Y here to create a kernel to run on the SGI 320 or 540.

	  A kernel compiled for the Visual Workstation will run on general
	  PCs as well. See <file:Documentation/sgi-visws.txt> for details.

config X86_SUMMIT
	bool "Summit/EXA (IBM x440)"
	depends on X86_32_NON_STANDARD
	---help---
	  This option is needed for IBM systems that use the Summit/EXA chipset.
	  In particular, it is needed for the x440.

config X86_ES7000
	bool "Unisys ES7000 IA32 series"
	depends on X86_32_NON_STANDARD && X86_BIGSMP
	---help---
	  Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
	  supposed to run on an IA32-based Unisys ES7000 system.

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 PARAVIRT_GUEST
	bool "Paravirtualized guest support"
	---help---
	  Say Y here to get to see options related to running Linux under
	  various hypervisors.  This option alone does not add any kernel code.

	  If you say N, all options in this submenu will be skipped and disabled.

if PARAVIRT_GUEST

source "arch/x86/xen/Kconfig"

config VMI
	bool "VMI Guest support"
	select PARAVIRT
	depends on X86_32
	---help---
	  VMI provides a paravirtualized interface to the VMware ESX server
	  (it could be used by other hypervisors in theory too, but is not
	  at the moment), by linking the kernel to a GPL-ed ROM module
	  provided by the hypervisor.

config KVM_CLOCK
	bool "KVM paravirtualized clock"
	select PARAVIRT
	select PARAVIRT_CLOCK
	---help---
	  Turning on this option will allow you to run a paravirtualized clock
	  when running over the KVM hypervisor. 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_GUEST
	bool "KVM Guest support"
	select PARAVIRT
	---help---
	  This option enables various optimizations for running under the KVM
	  hypervisor.

source "arch/x86/lguest/Kconfig"

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_CLOCK
	bool
	default n

endif

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 MEMTEST
	bool "Memtest"
	---help---
	  This option adds a kernel parameter 'memtest', which allows memtest
	  to be set.
	        memtest=0, mean disabled; -- default
	        memtest=1, mean do 1 test pattern;
	        ...
	        memtest=4, mean do 4 test patterns.
	  If you are unsure how to answer this question, answer N.

config X86_SUMMIT_NUMA
	def_bool y
	depends on X86_32 && NUMA && X86_32_NON_STANDARD

config X86_CYCLONE_TIMER
	def_bool y
	depends on X86_32_NON_STANDARD

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)

# Mark as embedded because too many people got it wrong.
# The code disables itself when not needed.
config DMI
	default y
	bool "Enable DMI scanning" if EMBEDDED
	---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 "GART IOMMU support" if EMBEDDED
	default y
	select SWIOTLB
	select AGP
	depends on X86_64 && PCI
	---help---
	  Support for full DMA access of devices with 32bit memory access only
	  on systems with more than 3GB. This is usually needed for USB,
	  sound, many IDE/SATA chipsets and some other devices.
	  Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
	  based hardware IOMMU and a software bounce buffer based IOMMU used
	  on Intel systems and as fallback.
	  The code is only active when needed (enough memory and limited
	  device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
	  too.

config CALGARY_IOMMU
	bool "IBM Calgary IOMMU support"
	select SWIOTLB
	depends on X86_64 && PCI && EXPERIMENTAL
	---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.

config AMD_IOMMU
	bool "AMD IOMMU support"
	select SWIOTLB
	select PCI_MSI
	depends on X86_64 && PCI && ACPI
	---help---
	  With this option you can enable support for AMD IOMMU hardware in
	  your system. An IOMMU is a hardware component which provides
	  remapping of DMA memory accesses from devices. With an AMD IOMMU you
	  can isolate the the DMA memory of different devices and protect the
	  system from misbehaving device drivers or hardware.

	  You can find out if your system has an AMD IOMMU if you look into
	  your BIOS for an option to enable it or if you have an IVRS ACPI
	  table.

config AMD_IOMMU_STATS
	bool "Export AMD IOMMU statistics to debugfs"
	depends on AMD_IOMMU
	select DEBUG_FS
	---help---
	  This option enables code in the AMD IOMMU driver to collect various
	  statistics about whats happening in the driver and exports that
	  information to userspace via debugfs.
	  If unsure, say N.

# 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 (e.g. the current generation
	  of Intel's x86-64 CPUs). 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 (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)

config IOMMU_API
	def_bool (AMD_IOMMU || DMAR)

config MAXSMP
	bool "Configure Maximum number of SMP Processors and NUMA Nodes"
	depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
	select CPUMASK_OFFSTACK
	default n
	---help---
	  Configure 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
	default "1" if !SMP
	default "4096" if MAXSMP
	default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
	default "8" if SMP
	---help---
	  This allows you to specify the maximum number of CPUs which this
	  kernel will support.  The maximum supported value is 512 and 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 X86_HT
	---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 X86_HT
	---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 X86_UP_APIC
	bool "Local APIC support on uniprocessors"
	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

config X86_IO_APIC
	def_bool y
	depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC

config X86_VISWS_APIC
	def_bool y
	depends on X86_32 && X86_VISWS

config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
	bool "Reroute for broken boot IRQs"
	default n
	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 Exception"
	---help---
	  Machine Check Exception support allows the processor to notify the
	  kernel if it detects a problem (e.g. overheating, component failure).
	  The action the kernel takes depends on the severity of the problem,
	  ranging from a warning message on the console, to halting the machine.
	  Your processor must be a Pentium or newer to support this - check the
	  flags in /proc/cpuinfo for mce.  Note that some older Pentium systems
	  have a design flaw which leads to false MCE events - hence MCE is
	  disabled on all P5 processors, unless explicitly enabled with "mce"
	  as a boot argument.  Similarly, if MCE is built in and creates a
	  problem on some new non-standard machine, you can boot with "nomce"
	  to disable it.  MCE support simply ignores non-MCE processors like
	  the 386 and 486, so nearly everyone can say Y here.

config X86_MCE_INTEL
	def_bool y
	prompt "Intel MCE features"
	depends on X86_64 && 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_64 && X86_MCE && X86_LOCAL_APIC
	---help---
	   Additional support for AMD specific MCE features such as
	   the DRAM Error Threshold.

config X86_MCE_THRESHOLD
	depends on X86_MCE_AMD || X86_MCE_INTEL
	bool
	default y

config X86_MCE_NONFATAL
	tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
	depends on X86_32 && X86_MCE
	---help---
	  Enabling this feature starts a timer that triggers every 5 seconds which
	  will look at the machine check registers to see if anything happened.
	  Non-fatal problems automatically get corrected (but still logged).
	  Disable this if you don't want to see these messages.
	  Seeing the messages this option prints out may be indicative of dying
	  or out-of-spec (ie, overclocked) hardware.
	  This option only does something on certain CPUs.
	  (AMD Athlon/Duron and Intel Pentium 4)

config X86_MCE_P4THERMAL
	bool "check for P4 thermal throttling interrupt."
	depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
	---help---
	  Enabling this feature will cause a message to be printed when the P4
	  enters thermal throttling.

config VM86
	bool "Enable VM86 support" if EMBEDDED
	default y
	depends on X86_32
	---help---
	  This option is required by programs like DOSEMU to run 16-bit legacy
	  code on X86 processors. It also may be needed by software like
	  XFree86 to initialize some video cards via BIOS. Disabling this
	  option saves about 6k.

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 laptop support"
	---help---
	  This adds a driver to safely access the System Management Mode
	  of the CPU on the Dell Inspiron 8000. The System Management Mode
	  is used to read cpu temperature and cooling fan status and to
	  control the fans on the I8K portables.

	  This driver has been tested only on the Inspiron 8000 but it may
	  also work with other Dell laptops. You can force loading on other
	  models by passing the parameter `force=1' to the module. Use at
	  your own risk.

	  For information on utilities to make use of this driver see the
	  I8K Linux utilities web site at:
	  <http://people.debian.org/~dz/i8k/>

	  Say Y if you intend to run this kernel on a Dell Inspiron 8000.
	  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
	tristate "/dev/cpu/microcode - microcode support"
	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 family 0x10 and
	  0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
	  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 patch loading support"
	depends on MICROCODE
	default MICROCODE
	select FW_LOADER
	---help---
	  This options enables microcode patch loading support for Intel
	  processors.

	  For latest news and information on obtaining all the required
	  Intel ingredients for this driver, check:
	  <http://www.urbanmyth.org/microcode/>.

config MICROCODE_AMD
	bool "AMD microcode patch 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.

config X86_CPU_DEBUG
	tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
	---help---
	  If you select this option, this will provide various x86 CPUs
	  information through debugfs.

choice
	prompt "High Memory Support"
	default HIGHMEM4G if !X86_NUMAQ
	default HIGHMEM64G if X86_NUMAQ
	depends on X86_32

config NOHIGHMEM
	bool "off"
	depends on !X86_NUMAQ
	---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"
	depends on !X86_NUMAQ
	---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 !M386 && !M486
	select X86_PAE
	---help---
	  Select this if you have a 32-bit processor and more than 4
	  gigabytes of physical RAM.

endchoice

choice
	depends on EXPERIMENTAL
	prompt "Memory split" if EMBEDDED
	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
	---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 X86_64 || X86_PAE

config DIRECT_GBPAGES
	bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
	default y
	depends on X86_64
	---help---
	  Allow the kernel linear mapping to use 1GB pages on CPUs that
	  support it. This can improve the kernel's performance a tiny bit by
	  reducing TLB pressure. If in doubt, say "Y".

# Common NUMA Features
config NUMA
	bool "Numa Memory Allocation and Scheduler Support"
	depends on SMP
	depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
	default y if (X86_NUMAQ || X86_SUMMIT || 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 on (rare) 32-bit-only platforms
	  that support NUMA topologies, such as NUMAQ / Summit, or if you
	  boot a 32-bit kernel on a 64-bit NUMA platform.

	  Otherwise, you should say N.

comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
	depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)

config K8_NUMA
	def_bool y
	prompt "Old style AMD Opteron NUMA detection"
	depends on X86_64 && NUMA && PCI
	---help---
	  Enable K8 NUMA node topology detection.  You should say Y here if
	  you have a multi processor AMD K8 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 X86_64 && 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 9
	default "9" if MAXSMP
	default "6" if X86_64
	default "4" if X86_NUMAQ
	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 HAVE_ARCH_BOOTMEM
	def_bool y
	depends on X86_32 && NUMA

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 HAVE_ARCH_ALLOC_REMAP
	def_bool y
	depends on X86_32 && NUMA

config ARCH_FLATMEM_ENABLE
	def_bool y
	depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !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_DEFAULT
	def_bool y
	depends on X86_64

config ARCH_SPARSEMEM_ENABLE
	def_bool y
	depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
	select SPARSEMEM_STATIC if X86_32
	select SPARSEMEM_VMEMMAP_ENABLE if X86_64

config ARCH_SELECT_MEMORY_MODEL
	def_bool y
	depends on ARCH_SPARSEMEM_ENABLE

config ARCH_MEMORY_PROBE
	def_bool X86_64
	depends on MEMORY_HOTPLUG

source "mm/Kconfig"

config HIGHPTE
	bool "Allocate 3rd-level pagetables from highmem"
	depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
	---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_64K
	bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
	default y
	---help---
	  Reserve the first 64K of physical RAM on BIOSes that are known
	  to potentially corrupt that memory range. A numbers of BIOSes are
	  known to utilize this area during suspend/resume, so it must not
	  be used by the kernel.

	  Set this to N if you are absolutely sure that you trust the BIOS
	  to get all its memory reservations and usages right.

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

	  Say Y if unsure.

config MATH_EMULATION
	bool
	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
	bool "MTRR (Memory Type Range Register) support"
	---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
	bool
	prompt "x86 PAT support"
	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 EFI
	bool "EFI runtime service support"
	depends on ACPI
	---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 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.

config CC_STACKPROTECTOR_ALL
	bool

config CC_STACKPROTECTOR
	bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
	select CC_STACKPROTECTOR_ALL
	---help---
	  This option turns on the -fstack-protector GCC feature. This
	  feature puts, at the beginning of functions, a canary value on
	  the stack just before the return address, and validates
	  the value just before actually returning.  Stack based buffer
	  overflows (that need to overwrite this return address) now also
	  overwrite the canary, which gets detected and the attack is then
	  neutralized via a kernel panic.

	  This feature requires gcc version 4.2 or above, or a distribution
	  gcc with the feature backported. Older versions are automatically
	  detected and for those versions, this configuration option is
	  ignored. (and a warning is printed during bootup)

source kernel/Kconfig.hz

config KEXEC
	bool "kexec system call"
	---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.  It may help to enable device hotplugging
	  support.  As of this writing the exact hardware interface is
	  strongly in flux, so no good recommendation can be made.

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 (EXPERIMENTAL)"
	depends on EXPERIMENTAL
	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 (EMBEDDED || CRASH_DUMP)
	default "0x1000000" if X86_NUMAQ
	default "0x200000" if X86_64
	default "0x100000"
	---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 0x100000 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 (Typically 16MB
	  0x1000000). 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. Typically this parameter is set as
	  crashkernel=64M@16M. 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 (EXPERIMENTAL)"
	depends on EXPERIMENTAL
	---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 ignored.

config PHYSICAL_ALIGN
	hex
	prompt "Alignment value to which kernel should be aligned" if X86_32
	default "0x100000" if X86_32
	default "0x200000" if X86_64
	range 0x2000 0x400000
	---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.

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

config HOTPLUG_CPU
	bool "Support for hot-pluggable CPUs"
	depends on SMP && HOTPLUG
	---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 COMPAT_VDSO
	def_bool y
	prompt "Compat VDSO support"
	depends on X86_32 || IA32_EMULATION
	---help---
	  Map the 32-bit VDSO to the predictable old-style address too.
	---help---
	  Say N here if you are running a sufficiently recent glibc
	  version (2.3.3 or later), to remove the high-mapped
	  VDSO mapping and to exclusively use the randomized VDSO.

	  If unsure, say Y.

config CMDLINE_BOOL
	bool "Built-in kernel command line"
	default n
	---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
	  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"
	default n
	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.

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 HAVE_ARCH_EARLY_PFN_TO_NID
	def_bool X86_64
	depends on NUMA

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"

config X86_APM_BOOT
	bool
	default y
	depends on APM || APM_MODULE

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/pm.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
	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 "arch/x86/kernel/cpu/cpufreq/Kconfig"

source "drivers/cpuidle/Kconfig"

source "drivers/idle/Kconfig"

endmenu


menu "Bus options (PCI etc.)"

config PCI
	bool "PCI support"
	default y
	select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
	---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"
	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))

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

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

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 DMAR
	bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
	depends on PCI_MSI && ACPI && EXPERIMENTAL
	help
	  DMA remapping (DMAR) devices support enables independent address
	  translations for Direct Memory Access (DMA) from devices.
	  These DMA remapping devices are reported via ACPI tables
	  and include PCI device scope covered by these DMA
	  remapping devices.

config DMAR_DEFAULT_ON
	def_bool y
	prompt "Enable DMA Remapping Devices by default"
	depends on DMAR
	help
	  Selecting this option will enable a DMAR device at boot time if
	  one is found. If this option is not selected, DMAR support can
	  be enabled by passing intel_iommu=on to the kernel. It is
	  recommended you say N here while the DMAR code remains
	  experimental.

config DMAR_GFX_WA
	def_bool y
	prompt "Support for Graphics workaround"
	depends on DMAR
	---help---
	  Current Graphics drivers tend to use physical address
	  for DMA and avoid using DMA APIs. Setting this config
	  option permits the IOMMU driver to set a unity map for
	  all the OS-visible memory. Hence the driver can continue
	  to use physical addresses for DMA.

config DMAR_FLOPPY_WA
	def_bool y
	depends on DMAR
	---help---
	  Floppy disk drivers are know to bypass DMA API calls
	  thereby failing to work when IOMMU is enabled. This
	  workaround will setup a 1:1 mapping for the first
	  16M to make floppy (an ISA device) work.

config INTR_REMAP
	bool "Support for Interrupt Remapping (EXPERIMENTAL)"
	depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
	---help---
	  Supports Interrupt remapping for IO-APIC and MSI devices.
	  To use x2apic mode in the CPU's which support x2APIC enhancements or
	  to support platforms with CPU's having > 8 bit APIC ID, say Y.

source "drivers/pci/pcie/Kconfig"

source "drivers/pci/Kconfig"

# x86_64 have no ISA slots, but do have ISA-style DMA.
config ISA_DMA_API
	def_bool 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 MCA
	bool "MCA support"
	---help---
	  MicroChannel Architecture is found in some IBM PS/2 machines and
	  laptops.  It is a bus system similar to PCI or ISA. See
	  <file:Documentation/mca.txt> (and especially the web page given
	  there) before attempting to build an MCA bus kernel.

source "drivers/mca/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 && GENERIC_TIME
	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 GEODE_MFGPT_TIMER
	def_bool y
	prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
	depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
	---help---
	  This driver provides a clock event source based on the MFGPT
	  timer(s) in the CS5535 and CS5536 companion chip for the geode.
	  MFGPTs have a better resolution and max interval than the
	  generic PIT, and are suitable for use as high-res timers.

config OLPC
	bool "One Laptop Per Child support"
	default n
	---help---
	  Add support for detecting the unique features of the OLPC
	  XO hardware.

endif # X86_32

config K8_NB
	def_bool y
	depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))

source "drivers/pcmcia/Kconfig"

source "drivers/pci/hotplug/Kconfig"

endmenu


menu "Executable file formats / Emulations"

source "fs/Kconfig.binfmt"

config IA32_EMULATION
	bool "IA32 Emulation"
	depends on X86_64
	select COMPAT_BINFMT_ELF
	---help---
	  Include code to run 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 COMPAT
	def_bool y
	depends on IA32_EMULATION

config COMPAT_FOR_U64_ALIGNMENT
	def_bool COMPAT
	depends on X86_64

config SYSVIPC_COMPAT
	def_bool y
	depends on COMPAT && SYSVIPC

endmenu


config HAVE_ATOMIC_IOMAP
	def_bool y
	depends on X86_32

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"