path: root/arch/x86/Kconfig.i386

#
# For a description of the syntax of this configuration file,
# see Documentation/kbuild/kconfig-language.txt.
#

mainmenu "Linux Kernel Configuration"

config X86_32
	bool
	default y
	help
	  This is Linux's home port.  Linux was originally native to the Intel
	  386, and runs on all the later x86 processors including the Intel
	  486, 586, Pentiums, and various instruction-set-compatible chips by
	  AMD, Cyrix, and others.

source "init/Kconfig"

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 the <file:Documentation/smp.txt>,
	  <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.

choice
	prompt "Subarchitecture Type"
	default X86_PC

config X86_PC
	bool "PC-compatible"
	help
	  Choose this option if your computer is a standard PC or compatible.

config X86_ELAN
	bool "AMD Elan"
	depends on X86_32
	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_VOYAGER
	bool "Voyager (NCR)"
	depends on X86_32
	select SMP if !BROKEN
	help
	  Voyager is an MCA-based 32-way capable SMP architecture proprietary
	  to NCR Corp.  Machine classes 345x/35xx/4100/51xx are Voyager-based.

	  *** WARNING ***

	  If you do not specifically know you have a Voyager based machine,
	  say N here, otherwise the kernel you build will not be bootable.

config X86_NUMAQ
	bool "NUMAQ (IBM/Sequent)"
	select SMP
	select NUMA
	depends on X86_32
	help
	  This option is used for getting Linux to run on a (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_SUMMIT
	bool "Summit/EXA (IBM x440)"
	depends on X86_32 && SMP
	help
	  This option is needed for IBM systems that use the Summit/EXA chipset.
	  In particular, it is needed for the x440.

	  If you don't have one of these computers, you should say N here.
	  If you want to build a NUMA kernel, you must select ACPI.

config X86_BIGSMP
	bool "Support for other sub-arch 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
	  and if the system is not of any sub-arch type above.

	  If you don't have such a system, you should say N here.

config X86_VISWS
	bool "SGI 320/540 (Visual Workstation)"
	depends on X86_32
	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 not run on PCs
	  and vice versa. See <file:Documentation/sgi-visws.txt> for details.

config X86_GENERICARCH
       bool "Generic architecture (Summit, bigsmp, ES7000, default)"
	depends on X86_32
       help
          This option compiles in the Summit, bigsmp, ES7000, default subarchitectures.
	  It is intended for a generic binary kernel.
	  If you want a NUMA kernel, select ACPI.   We need SRAT for NUMA.

config X86_ES7000
	bool "Support for Unisys ES7000 IA32 series"
	depends on X86_32 && SMP
	help
	  Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
	  supposed to run on an IA32-based Unisys ES7000 system.
	  Only choose this option if you have such a system, otherwise you
	  should say N here.

config X86_VSMP
	bool "Support for ScaleMP vSMP"
	depends on X86_64 && PCI
	 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.

endchoice

config SCHED_NO_NO_OMIT_FRAME_POINTER
	bool "Single-depth WCHAN output"
	default y
	depends on X86_32
	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".

config PARAVIRT
	bool
	depends on X86_32 && !(X86_VISWS || X86_VOYAGER)
	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.

menuconfig PARAVIRT_GUEST
	bool "Paravirtualized guest support"
	depends on X86_32
	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_VISWS || X86_VOYAGER)
	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.

source "arch/x86/lguest/Kconfig"

endif

config ACPI_SRAT
	bool
	default y
	depends on X86_32 && ACPI && NUMA && (X86_SUMMIT || X86_GENERICARCH)
	select ACPI_NUMA

config HAVE_ARCH_PARSE_SRAT
       bool
       default y
       depends on ACPI_SRAT

config X86_SUMMIT_NUMA
	bool
	default y
	depends on X86_32 && NUMA && (X86_SUMMIT || X86_GENERICARCH)

config X86_CYCLONE_TIMER
	bool
	default y
	depends on X86_32 && X86_SUMMIT || X86_GENERICARCH

config ES7000_CLUSTERED_APIC
	bool
	default y
	depends on SMP && X86_ES7000 && MPENTIUMIII

source "arch/x86/Kconfig.cpu"

config HPET_TIMER
	bool
	prompt "HPET Timer Support" if X86_32
	default X86_64
	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.htm>.

         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
	bool
	depends on HPET_TIMER && RTC=y
	default y

# Mark as embedded because too many people got it wrong.
# The code disables itself when not needed.
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
	bool "Should Calgary be enabled by default?"
	default y
	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
	bool
	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 NR_CPUS
	int "Maximum number of CPUs (2-255)"
	range 2 255
	depends on SMP
	default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
	default "8"
	help
	  This allows you to specify the maximum number of CPUs which this
	  kernel will support.  The maximum supported value is 255 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_64 && SMP) || (X86_32 && 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
	bool "Multi-core scheduler support"
	depends on (X86_64 && SMP) || (X86_32 && X86_HT)
	default y
	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_VISWS || X86_VOYAGER || X86_GENERICARCH)
	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
	bool
	depends on X86_64 || (X86_32 && (X86_UP_APIC || ((X86_VISWS || SMP) && !X86_VOYAGER) || X86_GENERICARCH))
	default y

config X86_IO_APIC
	bool
	depends on X86_64 || (X86_32 && (X86_UP_IOAPIC || (SMP && !(X86_VISWS || X86_VOYAGER)) || X86_GENERICARCH))
	default y

config X86_VISWS_APIC
	bool
	depends on X86_32 && X86_VISWS
	default y

config X86_MCE
	bool "Machine Check Exception"
	depends on !X86_VOYAGER
	---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
	bool "Intel MCE features"
	depends on X86_64 && X86_MCE && X86_LOCAL_APIC
	default y
	help
	   Additional support for intel specific MCE features such as
	   the thermal monitor.

config X86_MCE_AMD
	bool "AMD MCE features"
	depends on X86_64 && X86_MCE && X86_LOCAL_APIC
	default y
	help
	   Additional support for AMD specific MCE features such as
	   the DRAM Error Threshold.

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) && !X86_VISWS
	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"
	depends on X86_32
	---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 && X86
	default n
	---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.

	  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 - Intel IA32 CPU microcode support"
	select FW_LOADER
	---help---
	  If you say Y here, you will be able to update the microcode on
	  Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
	  Pentium III, Pentium 4, Xeon etc.  You will obviously need the
	  actual microcode binary data itself which is not shipped with the
	  Linux kernel.

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

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

config MICROCODE_OLD_INTERFACE
	bool
	depends on MICROCODE
	default y

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 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
	bool
	depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
	default y

config X86_PAE
	bool "PAE (Physical Address Extension) Support"
	default n
	depends on X86_32 && !HIGHMEM4G
	select RESOURCES_64BIT
	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.

# Common NUMA Features
config NUMA
	bool "Numa Memory Allocation and Scheduler Support (EXPERIMENTAL)"
	depends on SMP
	depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || (X86_SUMMIT || X86_GENERICARCH) && ACPI) && EXPERIMENTAL)
	default n if X86_PC
	default y if (X86_NUMAQ || X86_SUMMIT)
	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 i386 this is currently highly experimental and should be only
	  used for kernel development. It might also cause boot failures.
	  For x86_64 this is recommended on all multiprocessor Opteron systems.
	  If the system is EM64T, you should say N unless your system is
	  EM64T NUMA.

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

config K8_NUMA
       bool "Old style AMD Opteron NUMA detection"
       depends on X86_64 && NUMA && PCI
       default y
       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
	bool "ACPI NUMA detection"
	depends on X86_64 && NUMA && ACPI && PCI
	select ACPI_NUMA
	default y
	help
	  Enable ACPI SRAT based node topology detection.

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
	default "6" if X86_64
	default "4" if X86_NUMAQ
	default "3"
	depends on NEED_MULTIPLE_NODES

config HAVE_ARCH_BOOTMEM_NODE
	bool
	depends on X86_32 && NUMA
	default y

config ARCH_HAVE_MEMORY_PRESENT
	bool
	depends on X86_32 && DISCONTIGMEM
	default y

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

config HAVE_ARCH_ALLOC_REMAP
	bool
	depends on X86_32 && NUMA
	default y

config ARCH_FLATMEM_ENABLE
	def_bool y
	depends on (X86_32 && ARCH_SELECT_MEMORY_MODEL && X86_PC) || (X86_64 && !NUMA)

config ARCH_DISCONTIGMEM_ENABLE
	def_bool y
	depends on NUMA

config ARCH_DISCONTIGMEM_DEFAULT
	def_bool y
	depends on NUMA

config ARCH_SPARSEMEM_ENABLE
	def_bool y
	depends on NUMA || (EXPERIMENTAL && (X86_PC || X86_64))
	select SPARSEMEM_STATIC if X86_32
	select SPARSEMEM_VMEMMAP_ENABLE if X86_64

config ARCH_SELECT_MEMORY_MODEL
	def_bool y
	depends on X86_32 && 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 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/mtrr.txt> for more information.

config EFI
	bool "Boot from EFI support"
	depends on X86_32 && ACPI
	default n
	---help---
	This enables the kernel to boot on EFI platforms using
	system configuration information passed to it from the firmware.
	This also enables the kernel to use any EFI runtime services that are
	available (such as the EFI variable services).

	This option is only useful on systems that have EFI firmware
	and will result in a kernel image that is ~8k larger.  In addition,
	you must use the latest ELILO loader available at
	<http://elilo.sourceforge.net> in order to take advantage of
	kernel initialization using EFI information (neither GRUB nor LILO know
	anything about EFI).  However, even with this option, the resultant
	kernel should continue to boot on existing non-EFI platforms.

config IRQBALANCE
 	bool "Enable kernel irq balancing"
	depends on X86_32 && SMP && X86_IO_APIC
	default y
	help
 	  The default yes will allow the kernel to do irq load balancing.
	  Saying no will keep the kernel from doing irq load balancing.

# turning this on wastes a bunch of space.
# Summit needs it only when NUMA is on
config BOOT_IOREMAP
	bool
	depends on X86_32 && (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
	default y

config SECCOMP
	bool "Enable seccomp to safely compute untrusted bytecode"
	depends on PROC_FS
	default y
	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 /proc/<pid>/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
	bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
	depends on X86_64 && EXPERIMENTAL
	help
         This option turns on the -fstack-protector GCC feature. This
	  feature puts, at the beginning of critical 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.

config CC_STACKPROTECTOR_ALL
	bool "Use stack-protector for all functions"
	depends on CC_STACKPROTECTOR
	help
	  Normally, GCC only inserts the canary value protection for
	  functions that use large-ish on-stack buffers. By enabling
	  this option, GCC will be asked to do this for ALL functions.

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 (EXPERIMENTAL)"
	depends on EXPERIMENTAL
	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 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 suspend on SMP and hot-pluggable CPUs (EXPERIMENTAL)"
	depends on SMP && HOTPLUG && EXPERIMENTAL && !X86_VOYAGER
	---help---
	  Say Y here to experiment with turning CPUs off and on, and to
	  enable suspend on SMP systems. CPUs can be controlled through
	  /sys/devices/system/cpu.
	  Say N if you want to disable CPU hotplug and don't need to
	  suspend.

config COMPAT_VDSO
	bool "Compat VDSO support"
	default y
	depends on X86_32
	help
	  Map the 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.

endmenu

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

config MEMORY_HOTPLUG_RESERVE
	def_bool X86_64
	depends on (MEMORY_HOTPLUG && DISCONTIGMEM)

config HAVE_ARCH_EARLY_PFN_TO_NID
	def_bool X86_64
	depends on NUMA

config OUT_OF_LINE_PFN_TO_PAGE
	def_bool X86_64
	depends on DISCONTIGMEM

source "arch/x86/Kconfig"