arch/x86/Kconfig

   1 # x86 configuration
   2 mainmenu "Linux Kernel Configuration for x86"
   3
   4 # Select 32 or 64 bit
   5 config 64BIT
   6         bool "64-bit kernel" if ARCH = "x86"
   7         default ARCH = "x86_64"
   8         ---help---
   9           Say yes to build a 64-bit kernel - formerly known as x86_64
  10           Say no to build a 32-bit kernel - formerly known as i386
  11
  12 config X86_32
  13         def_bool !64BIT
  14
  15 config X86_64
  16         def_bool 64BIT
  17
  18 ### Arch settings
  19 config X86
  20         def_bool y
  21         select HAVE_AOUT if X86_32
  22         select HAVE_READQ
  23         select HAVE_WRITEQ
  24         select HAVE_UNSTABLE_SCHED_CLOCK
  25         select HAVE_IDE
  26         select HAVE_OPROFILE
  27         select HAVE_IOREMAP_PROT
  28         select HAVE_KPROBES
  29         select ARCH_WANT_OPTIONAL_GPIOLIB
  30         select ARCH_WANT_FRAME_POINTERS
  31         select HAVE_KRETPROBES
  32         select HAVE_FTRACE_MCOUNT_RECORD
  33         select HAVE_DYNAMIC_FTRACE
  34         select HAVE_FUNCTION_TRACER
  35         select HAVE_FUNCTION_GRAPH_TRACER
  36         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  37         select HAVE_KVM
  38         select HAVE_ARCH_KGDB
  39         select HAVE_ARCH_TRACEHOOK
  40         select HAVE_GENERIC_DMA_COHERENT if X86_32
  41         select HAVE_EFFICIENT_UNALIGNED_ACCESS
  42         select USER_STACKTRACE_SUPPORT
  43         select HAVE_KERNEL_GZIP
  44         select HAVE_KERNEL_BZIP2
  45         select HAVE_KERNEL_LZMA
  46
  47 config ARCH_DEFCONFIG
  48         string
  49         default "arch/x86/configs/i386_defconfig" if X86_32
  50         default "arch/x86/configs/x86_64_defconfig" if X86_64
  51
  52 config GENERIC_TIME
  53         def_bool y
  54
  55 config GENERIC_CMOS_UPDATE
  56         def_bool y
  57
  58 config CLOCKSOURCE_WATCHDOG
  59         def_bool y
  60
  61 config GENERIC_CLOCKEVENTS
  62         def_bool y
  63
  64 config GENERIC_CLOCKEVENTS_BROADCAST
  65         def_bool y
  66         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  67
  68 config LOCKDEP_SUPPORT
  69         def_bool y
  70
  71 config STACKTRACE_SUPPORT
  72         def_bool y
  73
  74 config HAVE_LATENCYTOP_SUPPORT
  75         def_bool y
  76
  77 config FAST_CMPXCHG_LOCAL
  78         bool
  79         default y
  80
  81 config MMU
  82         def_bool y
  83
  84 config ZONE_DMA
  85         def_bool y
  86
  87 config SBUS
  88         bool
  89
  90 config GENERIC_ISA_DMA
  91         def_bool y
  92
  93 config GENERIC_IOMAP
  94         def_bool y
  95
  96 config GENERIC_BUG
  97         def_bool y
  98         depends on BUG
  99         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 100
 101 config GENERIC_BUG_RELATIVE_POINTERS
 102         bool
 103
 104 config GENERIC_HWEIGHT
 105         def_bool y
 106
 107 config GENERIC_GPIO
 108         bool
 109
 110 config ARCH_MAY_HAVE_PC_FDC
 111         def_bool y
 112
 113 config RWSEM_GENERIC_SPINLOCK
 114         def_bool !X86_XADD
 115
 116 config RWSEM_XCHGADD_ALGORITHM
 117         def_bool X86_XADD
 118
 119 config ARCH_HAS_CPU_IDLE_WAIT
 120         def_bool y
 121
 122 config GENERIC_CALIBRATE_DELAY
 123         def_bool y
 124
 125 config GENERIC_TIME_VSYSCALL
 126         bool
 127         default X86_64
 128
 129 config ARCH_HAS_CPU_RELAX
 130         def_bool y
 131
 132 config ARCH_HAS_DEFAULT_IDLE
 133         def_bool y
 134
 135 config ARCH_HAS_CACHE_LINE_SIZE
 136         def_bool y
 137
 138 config HAVE_SETUP_PER_CPU_AREA
 139         def_bool y
 140
 141 config HAVE_CPUMASK_OF_CPU_MAP
 142         def_bool X86_64_SMP
 143
 144 config ARCH_HIBERNATION_POSSIBLE
 145         def_bool y
 146
 147 config ARCH_SUSPEND_POSSIBLE
 148         def_bool y
 149
 150 config ZONE_DMA32
 151         bool
 152         default X86_64
 153
 154 config ARCH_POPULATES_NODE_MAP
 155         def_bool y
 156
 157 config AUDIT_ARCH
 158         bool
 159         default X86_64
 160
 161 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 162         def_bool y
 163
 164 # Use the generic interrupt handling code in kernel/irq/:
 165 config GENERIC_HARDIRQS
 166         bool
 167         default y
 168
 169 config GENERIC_IRQ_PROBE
 170         bool
 171         default y
 172
 173 config GENERIC_PENDING_IRQ
 174         bool
 175         depends on GENERIC_HARDIRQS && SMP
 176         default y
 177
 178 config USE_GENERIC_SMP_HELPERS
 179         def_bool y
 180         depends on SMP
 181
 182 config X86_32_SMP
 183         def_bool y
 184         depends on X86_32 && SMP
 185
 186 config X86_64_SMP
 187         def_bool y
 188         depends on X86_64 && SMP
 189
 190 config X86_HT
 191         bool
 192         depends on SMP
 193         default y
 194
 195 config X86_TRAMPOLINE
 196         bool
 197         depends on SMP || (64BIT && ACPI_SLEEP)
 198         default y
 199
 200 config X86_32_LAZY_GS
 201         def_bool y
 202         depends on X86_32 && !CC_STACKPROTECTOR
 203
 204 config KTIME_SCALAR
 205         def_bool X86_32
 206 source "init/Kconfig"
 207 source "kernel/Kconfig.freezer"
 208
 209 menu "Processor type and features"
 210
 211 source "kernel/time/Kconfig"
 212
 213 config SMP
 214         bool "Symmetric multi-processing support"
 215         ---help---
 216           This enables support for systems with more than one CPU. If you have
 217           a system with only one CPU, like most personal computers, say N. If
 218           you have a system with more than one CPU, say Y.
 219
 220           If you say N here, the kernel will run on single and multiprocessor
 221           machines, but will use only one CPU of a multiprocessor machine. If
 222           you say Y here, the kernel will run on many, but not all,
 223           singleprocessor machines. On a singleprocessor machine, the kernel
 224           will run faster if you say N here.
 225
 226           Note that if you say Y here and choose architecture "586" or
 227           "Pentium" under "Processor family", the kernel will not work on 486
 228           architectures. Similarly, multiprocessor kernels for the "PPro"
 229           architecture may not work on all Pentium based boards.
 230
 231           People using multiprocessor machines who say Y here should also say
 232           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 233           Management" code will be disabled if you say Y here.
 234
 235           See also <file:Documentation/i386/IO-APIC.txt>,
 236           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 237           <http://www.tldp.org/docs.html#howto>.
 238
 239           If you don't know what to do here, say N.
 240
 241 config X86_X2APIC
 242         bool "Support x2apic"
 243         depends on X86_LOCAL_APIC && X86_64
 244         ---help---
 245           This enables x2apic support on CPUs that have this feature.
 246
 247           This allows 32-bit apic IDs (so it can support very large systems),
 248           and accesses the local apic via MSRs not via mmio.
 249
 250           ( On certain CPU models you may need to enable INTR_REMAP too,
 251             to get functional x2apic mode. )
 252
 253           If you don't know what to do here, say N.
 254
 255 config SPARSE_IRQ
 256         bool "Support sparse irq numbering"
 257         depends on PCI_MSI || HT_IRQ
 258         ---help---
 259           This enables support for sparse irqs. This is useful for distro
 260           kernels that want to define a high CONFIG_NR_CPUS value but still
 261           want to have low kernel memory footprint on smaller machines.
 262
 263           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 264             out the irq_desc[] array in a more NUMA-friendly way. )
 265
 266           If you don't know what to do here, say N.
 267
 268 config NUMA_MIGRATE_IRQ_DESC
 269         bool "Move irq desc when changing irq smp_affinity"
 270         depends on SPARSE_IRQ && NUMA
 271         default n
 272         ---help---
 273           This enables moving irq_desc to cpu/node that irq will use handled.
 274
 275           If you don't know what to do here, say N.
 276
 277 config X86_MPPARSE
 278         bool "Enable MPS table" if ACPI
 279         default y
 280         depends on X86_LOCAL_APIC
 281         ---help---
 282           For old smp systems that do not have proper acpi support. Newer systems
 283           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 284
 285 config X86_BIGSMP
 286         bool "Support for big SMP systems with more than 8 CPUs"
 287         depends on X86_32 && SMP
 288         ---help---
 289           This option is needed for the systems that have more than 8 CPUs
 290
 291 if X86_32
 292 config X86_EXTENDED_PLATFORM
 293         bool "Support for extended (non-PC) x86 platforms"
 294         default y
 295         ---help---
 296           If you disable this option then the kernel will only support
 297           standard PC platforms. (which covers the vast majority of
 298           systems out there.)
 299
 300           If you enable this option then you'll be able to select support
 301           for the following (non-PC) 32 bit x86 platforms:
 302                 AMD Elan
 303                 NUMAQ (IBM/Sequent)
 304                 RDC R-321x SoC
 305                 SGI 320/540 (Visual Workstation)
 306                 Summit/EXA (IBM x440)
 307                 Unisys ES7000 IA32 series
 308
 309           If you have one of these systems, or if you want to build a
 310           generic distribution kernel, say Y here - otherwise say N.
 311 endif
 312
 313 if X86_64
 314 config X86_EXTENDED_PLATFORM
 315         bool "Support for extended (non-PC) x86 platforms"
 316         default y
 317         ---help---
 318           If you disable this option then the kernel will only support
 319           standard PC platforms. (which covers the vast majority of
 320           systems out there.)
 321
 322           If you enable this option then you'll be able to select support
 323           for the following (non-PC) 64 bit x86 platforms:
 324                 ScaleMP vSMP
 325                 SGI Ultraviolet
 326
 327           If you have one of these systems, or if you want to build a
 328           generic distribution kernel, say Y here - otherwise say N.
 329 endif
 330 # This is an alphabetically sorted list of 64 bit extended platforms
 331 # Please maintain the alphabetic order if and when there are additions
 332
 333 config X86_VSMP
 334         bool "ScaleMP vSMP"
 335         select PARAVIRT
 336         depends on X86_64 && PCI
 337         depends on X86_EXTENDED_PLATFORM
 338         ---help---
 339           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 340           supposed to run on these EM64T-based machines.  Only choose this option
 341           if you have one of these machines.
 342
 343 config X86_UV
 344         bool "SGI Ultraviolet"
 345         depends on X86_64
 346         depends on X86_EXTENDED_PLATFORM
 347         select X86_X2APIC
 348         ---help---
 349           This option is needed in order to support SGI Ultraviolet systems.
 350           If you don't have one of these, you should say N here.
 351
 352 # Following is an alphabetically sorted list of 32 bit extended platforms
 353 # Please maintain the alphabetic order if and when there are additions
 354
 355 config X86_ELAN
 356         bool "AMD Elan"
 357         depends on X86_32
 358         depends on X86_EXTENDED_PLATFORM
 359         ---help---
 360           Select this for an AMD Elan processor.
 361
 362           Do not use this option for K6/Athlon/Opteron processors!
 363
 364           If unsure, choose "PC-compatible" instead.
 365
 366 config X86_RDC321X
 367         bool "RDC R-321x SoC"
 368         depends on X86_32
 369         depends on X86_EXTENDED_PLATFORM
 370         select M486
 371         select X86_REBOOTFIXUPS
 372         ---help---
 373           This option is needed for RDC R-321x system-on-chip, also known
 374           as R-8610-(G).
 375           If you don't have one of these chips, you should say N here.
 376
 377 config X86_32_NON_STANDARD
 378         bool "Support non-standard 32-bit SMP architectures"
 379         depends on X86_32 && SMP
 380         depends on X86_EXTENDED_PLATFORM
 381         ---help---
 382           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 383           subarchitectures.  It is intended for a generic binary kernel.
 384           if you select them all, kernel will probe it one by one. and will
 385           fallback to default.
 386
 387 # Alphabetically sorted list of Non standard 32 bit platforms
 388
 389 config X86_NUMAQ
 390         bool "NUMAQ (IBM/Sequent)"
 391         depends on X86_32_NON_STANDARD
 392         select NUMA
 393         select X86_MPPARSE
 394         ---help---
 395           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 396           NUMA multiquad box. This changes the way that processors are
 397           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 398           of Flat Logical.  You will need a new lynxer.elf file to flash your
 399           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 400
 401 config X86_VISWS
 402         bool "SGI 320/540 (Visual Workstation)"
 403         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 404         depends on X86_32_NON_STANDARD
 405         ---help---
 406           The SGI Visual Workstation series is an IA32-based workstation
 407           based on SGI systems chips with some legacy PC hardware attached.
 408
 409           Say Y here to create a kernel to run on the SGI 320 or 540.
 410
 411           A kernel compiled for the Visual Workstation will run on general
 412           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 413
 414 config X86_SUMMIT
 415         bool "Summit/EXA (IBM x440)"
 416         depends on X86_32_NON_STANDARD
 417         ---help---
 418           This option is needed for IBM systems that use the Summit/EXA chipset.
 419           In particular, it is needed for the x440.
 420
 421 config X86_ES7000
 422         bool "Unisys ES7000 IA32 series"
 423         depends on X86_32_NON_STANDARD && X86_BIGSMP
 424         ---help---
 425           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 426           supposed to run on an IA32-based Unisys ES7000 system.
 427
 428 config SCHED_OMIT_FRAME_POINTER
 429         def_bool y
 430         prompt "Single-depth WCHAN output"
 431         depends on X86
 432         ---help---
 433           Calculate simpler /proc/<PID>/wchan values. If this option
 434           is disabled then wchan values will recurse back to the
 435           caller function. This provides more accurate wchan values,
 436           at the expense of slightly more scheduling overhead.
 437
 438           If in doubt, say "Y".
 439
 440 menuconfig PARAVIRT_GUEST
 441         bool "Paravirtualized guest support"
 442         ---help---
 443           Say Y here to get to see options related to running Linux under
 444           various hypervisors.  This option alone does not add any kernel code.
 445
 446           If you say N, all options in this submenu will be skipped and disabled.
 447
 448 if PARAVIRT_GUEST
 449
 450 source "arch/x86/xen/Kconfig"
 451
 452 config VMI
 453         bool "VMI Guest support"
 454         select PARAVIRT
 455         depends on X86_32
 456         ---help---
 457           VMI provides a paravirtualized interface to the VMware ESX server
 458           (it could be used by other hypervisors in theory too, but is not
 459           at the moment), by linking the kernel to a GPL-ed ROM module
 460           provided by the hypervisor.
 461
 462 config KVM_CLOCK
 463         bool "KVM paravirtualized clock"
 464         select PARAVIRT
 465         select PARAVIRT_CLOCK
 466         ---help---
 467           Turning on this option will allow you to run a paravirtualized clock
 468           when running over the KVM hypervisor. Instead of relying on a PIT
 469           (or probably other) emulation by the underlying device model, the host
 470           provides the guest with timing infrastructure such as time of day, and
 471           system time
 472
 473 config KVM_GUEST
 474         bool "KVM Guest support"
 475         select PARAVIRT
 476         ---help---
 477           This option enables various optimizations for running under the KVM
 478           hypervisor.
 479
 480 source "arch/x86/lguest/Kconfig"
 481
 482 config PARAVIRT
 483         bool "Enable paravirtualization code"
 484         ---help---
 485           This changes the kernel so it can modify itself when it is run
 486           under a hypervisor, potentially improving performance significantly
 487           over full virtualization.  However, when run without a hypervisor
 488           the kernel is theoretically slower and slightly larger.
 489
 490 config PARAVIRT_CLOCK
 491         bool
 492         default n
 493
 494 endif
 495
 496 config PARAVIRT_DEBUG
 497         bool "paravirt-ops debugging"
 498         depends on PARAVIRT && DEBUG_KERNEL
 499         ---help---
 500           Enable to debug paravirt_ops internals.  Specifically, BUG if
 501           a paravirt_op is missing when it is called.
 502
 503 config MEMTEST
 504         bool "Memtest"
 505         ---help---
 506           This option adds a kernel parameter 'memtest', which allows memtest
 507           to be set.
 508                 memtest=0, mean disabled; -- default
 509                 memtest=1, mean do 1 test pattern;
 510                 ...
 511                 memtest=4, mean do 4 test patterns.
 512           If you are unsure how to answer this question, answer N.
 513
 514 config X86_SUMMIT_NUMA
 515         def_bool y
 516         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 517
 518 config X86_CYCLONE_TIMER
 519         def_bool y
 520         depends on X86_32_NON_STANDARD
 521
 522 source "arch/x86/Kconfig.cpu"
 523
 524 config HPET_TIMER
 525         def_bool X86_64
 526         prompt "HPET Timer Support" if X86_32
 527         ---help---
 528           Use the IA-PC HPET (High Precision Event Timer) to manage
 529           time in preference to the PIT and RTC, if a HPET is
 530           present.
 531           HPET is the next generation timer replacing legacy 8254s.
 532           The HPET provides a stable time base on SMP
 533           systems, unlike the TSC, but it is more expensive to access,
 534           as it is off-chip.  You can find the HPET spec at
 535           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 536
 537           You can safely choose Y here.  However, HPET will only be
 538           activated if the platform and the BIOS support this feature.
 539           Otherwise the 8254 will be used for timing services.
 540
 541           Choose N to continue using the legacy 8254 timer.
 542
 543 config HPET_EMULATE_RTC
 544         def_bool y
 545         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 546
 547 # Mark as embedded because too many people got it wrong.
 548 # The code disables itself when not needed.
 549 config DMI
 550         default y
 551         bool "Enable DMI scanning" if EMBEDDED
 552         ---help---
 553           Enabled scanning of DMI to identify machine quirks. Say Y
 554           here unless you have verified that your setup is not
 555           affected by entries in the DMI blacklist. Required by PNP
 556           BIOS code.
 557
 558 config GART_IOMMU
 559         bool "GART IOMMU support" if EMBEDDED
 560         default y
 561         select SWIOTLB
 562         select AGP
 563         depends on X86_64 && PCI
 564         ---help---
 565           Support for full DMA access of devices with 32bit memory access only
 566           on systems with more than 3GB. This is usually needed for USB,
 567           sound, many IDE/SATA chipsets and some other devices.
 568           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 569           based hardware IOMMU and a software bounce buffer based IOMMU used
 570           on Intel systems and as fallback.
 571           The code is only active when needed (enough memory and limited
 572           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 573           too.
 574
 575 config CALGARY_IOMMU
 576         bool "IBM Calgary IOMMU support"
 577         select SWIOTLB
 578         depends on X86_64 && PCI && EXPERIMENTAL
 579         ---help---
 580           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 581           systems. Needed to run systems with more than 3GB of memory
 582           properly with 32-bit PCI devices that do not support DAC
 583           (Double Address Cycle). Calgary also supports bus level
 584           isolation, where all DMAs pass through the IOMMU.  This
 585           prevents them from going anywhere except their intended
 586           destination. This catches hard-to-find kernel bugs and
 587           mis-behaving drivers and devices that do not use the DMA-API
 588           properly to set up their DMA buffers.  The IOMMU can be
 589           turned off at boot time with the iommu=off parameter.
 590           Normally the kernel will make the right choice by itself.
 591           If unsure, say Y.
 592
 593 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 594         def_bool y
 595         prompt "Should Calgary be enabled by default?"
 596         depends on CALGARY_IOMMU
 597         ---help---
 598           Should Calgary be enabled by default? if you choose 'y', Calgary
 599           will be used (if it exists). If you choose 'n', Calgary will not be
 600           used even if it exists. If you choose 'n' and would like to use
 601           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 602           If unsure, say Y.
 603
 604 config AMD_IOMMU
 605         bool "AMD IOMMU support"
 606         select SWIOTLB
 607         select PCI_MSI
 608         depends on X86_64 && PCI && ACPI
 609         ---help---
 610           With this option you can enable support for AMD IOMMU hardware in
 611           your system. An IOMMU is a hardware component which provides
 612           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 613           can isolate the the DMA memory of different devices and protect the
 614           system from misbehaving device drivers or hardware.
 615
 616           You can find out if your system has an AMD IOMMU if you look into
 617           your BIOS for an option to enable it or if you have an IVRS ACPI
 618           table.
 619
 620 config AMD_IOMMU_STATS
 621         bool "Export AMD IOMMU statistics to debugfs"
 622         depends on AMD_IOMMU
 623         select DEBUG_FS
 624         ---help---
 625           This option enables code in the AMD IOMMU driver to collect various
 626           statistics about whats happening in the driver and exports that
 627           information to userspace via debugfs.
 628           If unsure, say N.
 629
 630 # need this always selected by IOMMU for the VIA workaround
 631 config SWIOTLB
 632         def_bool y if X86_64
 633         ---help---
 634           Support for software bounce buffers used on x86-64 systems
 635           which don't have a hardware IOMMU (e.g. the current generation
 636           of Intel's x86-64 CPUs). Using this PCI devices which can only
 637           access 32-bits of memory can be used on systems with more than
 638           3 GB of memory. If unsure, say Y.
 639
 640 config IOMMU_HELPER
 641         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 642
 643 config IOMMU_API
 644         def_bool (AMD_IOMMU || DMAR)
 645
 646 config MAXSMP
 647         bool "Configure Maximum number of SMP Processors and NUMA Nodes"
 648         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 649         select CPUMASK_OFFSTACK
 650         default n
 651         ---help---
 652           Configure maximum number of CPUS and NUMA Nodes for this architecture.
 653           If unsure, say N.
 654
 655 config NR_CPUS
 656         int "Maximum number of CPUs" if SMP && !MAXSMP
 657         range 2 512 if SMP && !MAXSMP
 658         default "1" if !SMP
 659         default "4096" if MAXSMP
 660         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 661         default "8" if SMP
 662         ---help---
 663           This allows you to specify the maximum number of CPUs which this
 664           kernel will support.  The maximum supported value is 512 and the
 665           minimum value which makes sense is 2.
 666
 667           This is purely to save memory - each supported CPU adds
 668           approximately eight kilobytes to the kernel image.
 669
 670 config SCHED_SMT
 671         bool "SMT (Hyperthreading) scheduler support"
 672         depends on X86_HT
 673         ---help---
 674           SMT scheduler support improves the CPU scheduler's decision making
 675           when dealing with Intel Pentium 4 chips with HyperThreading at a
 676           cost of slightly increased overhead in some places. If unsure say
 677           N here.
 678
 679 config SCHED_MC
 680         def_bool y
 681         prompt "Multi-core scheduler support"
 682         depends on X86_HT
 683         ---help---
 684           Multi-core scheduler support improves the CPU scheduler's decision
 685           making when dealing with multi-core CPU chips at a cost of slightly
 686           increased overhead in some places. If unsure say N here.
 687
 688 source "kernel/Kconfig.preempt"
 689
 690 config X86_UP_APIC
 691         bool "Local APIC support on uniprocessors"
 692         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 693         ---help---
 694           A local APIC (Advanced Programmable Interrupt Controller) is an
 695           integrated interrupt controller in the CPU. If you have a single-CPU
 696           system which has a processor with a local APIC, you can say Y here to
 697           enable and use it. If you say Y here even though your machine doesn't
 698           have a local APIC, then the kernel will still run with no slowdown at
 699           all. The local APIC supports CPU-generated self-interrupts (timer,
 700           performance counters), and the NMI watchdog which detects hard
 701           lockups.
 702
 703 config X86_UP_IOAPIC
 704         bool "IO-APIC support on uniprocessors"
 705         depends on X86_UP_APIC
 706         ---help---
 707           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 708           SMP-capable replacement for PC-style interrupt controllers. Most
 709           SMP systems and many recent uniprocessor systems have one.
 710
 711           If you have a single-CPU system with an IO-APIC, you can say Y here
 712           to use it. If you say Y here even though your machine doesn't have
 713           an IO-APIC, then the kernel will still run with no slowdown at all.
 714
 715 config X86_LOCAL_APIC
 716         def_bool y
 717         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 718
 719 config X86_IO_APIC
 720         def_bool y
 721         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 722
 723 config X86_VISWS_APIC
 724         def_bool y
 725         depends on X86_32 && X86_VISWS
 726
 727 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 728         bool "Reroute for broken boot IRQs"
 729         default n
 730         depends on X86_IO_APIC
 731         ---help---
 732           This option enables a workaround that fixes a source of
 733           spurious interrupts. This is recommended when threaded
 734           interrupt handling is used on systems where the generation of
 735           superfluous "boot interrupts" cannot be disabled.
 736
 737           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 738           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 739           kernel does during interrupt handling). On chipsets where this
 740           boot IRQ generation cannot be disabled, this workaround keeps
 741           the original IRQ line masked so that only the equivalent "boot
 742           IRQ" is delivered to the CPUs. The workaround also tells the
 743           kernel to set up the IRQ handler on the boot IRQ line. In this
 744           way only one interrupt is delivered to the kernel. Otherwise
 745           the spurious second interrupt may cause the kernel to bring
 746           down (vital) interrupt lines.
 747
 748           Only affects "broken" chipsets. Interrupt sharing may be
 749           increased on these systems.
 750
 751 config X86_MCE
 752         bool "Machine Check Exception"
 753         ---help---
 754           Machine Check Exception support allows the processor to notify the
 755           kernel if it detects a problem (e.g. overheating, component failure).
 756           The action the kernel takes depends on the severity of the problem,
 757           ranging from a warning message on the console, to halting the machine.
 758           Your processor must be a Pentium or newer to support this - check the
 759           flags in /proc/cpuinfo for mce.  Note that some older Pentium systems
 760           have a design flaw which leads to false MCE events - hence MCE is
 761           disabled on all P5 processors, unless explicitly enabled with "mce"
 762           as a boot argument.  Similarly, if MCE is built in and creates a
 763           problem on some new non-standard machine, you can boot with "nomce"
 764           to disable it.  MCE support simply ignores non-MCE processors like
 765           the 386 and 486, so nearly everyone can say Y here.
 766
 767 config X86_MCE_INTEL
 768         def_bool y
 769         prompt "Intel MCE features"
 770         depends on X86_64 && X86_MCE && X86_LOCAL_APIC
 771         ---help---
 772            Additional support for intel specific MCE features such as
 773            the thermal monitor.
 774
 775 config X86_MCE_AMD
 776         def_bool y
 777         prompt "AMD MCE features"
 778         depends on X86_64 && X86_MCE && X86_LOCAL_APIC
 779         ---help---
 780            Additional support for AMD specific MCE features such as
 781            the DRAM Error Threshold.
 782
 783 config X86_MCE_NONFATAL
 784         tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
 785         depends on X86_32 && X86_MCE
 786         ---help---
 787           Enabling this feature starts a timer that triggers every 5 seconds which
 788           will look at the machine check registers to see if anything happened.
 789           Non-fatal problems automatically get corrected (but still logged).
 790           Disable this if you don't want to see these messages.
 791           Seeing the messages this option prints out may be indicative of dying
 792           or out-of-spec (ie, overclocked) hardware.
 793           This option only does something on certain CPUs.
 794           (AMD Athlon/Duron and Intel Pentium 4)
 795
 796 config X86_MCE_P4THERMAL
 797         bool "check for P4 thermal throttling interrupt."
 798         depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
 799         ---help---
 800           Enabling this feature will cause a message to be printed when the P4
 801           enters thermal throttling.
 802
 803 config VM86
 804         bool "Enable VM86 support" if EMBEDDED
 805         default y
 806         depends on X86_32
 807         ---help---
 808           This option is required by programs like DOSEMU to run 16-bit legacy
 809           code on X86 processors. It also may be needed by software like
 810           XFree86 to initialize some video cards via BIOS. Disabling this
 811           option saves about 6k.
 812
 813 config TOSHIBA
 814         tristate "Toshiba Laptop support"
 815         depends on X86_32
 816         ---help---
 817           This adds a driver to safely access the System Management Mode of
 818           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 819           not work on models with a Phoenix BIOS. The System Management Mode
 820           is used to set the BIOS and power saving options on Toshiba portables.
 821
 822           For information on utilities to make use of this driver see the
 823           Toshiba Linux utilities web site at:
 824           <http://www.buzzard.org.uk/toshiba/>.
 825
 826           Say Y if you intend to run this kernel on a Toshiba portable.
 827           Say N otherwise.
 828
 829 config I8K
 830         tristate "Dell laptop support"
 831         ---help---
 832           This adds a driver to safely access the System Management Mode
 833           of the CPU on the Dell Inspiron 8000. The System Management Mode
 834           is used to read cpu temperature and cooling fan status and to
 835           control the fans on the I8K portables.
 836
 837           This driver has been tested only on the Inspiron 8000 but it may
 838           also work with other Dell laptops. You can force loading on other
 839           models by passing the parameter `force=1' to the module. Use at
 840           your own risk.
 841
 842           For information on utilities to make use of this driver see the
 843           I8K Linux utilities web site at:
 844           <http://people.debian.org/~dz/i8k/>
 845
 846           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 847           Say N otherwise.
 848
 849 config X86_REBOOTFIXUPS
 850         bool "Enable X86 board specific fixups for reboot"
 851         depends on X86_32
 852         ---help---
 853           This enables chipset and/or board specific fixups to be done
 854           in order to get reboot to work correctly. This is only needed on
 855           some combinations of hardware and BIOS. The symptom, for which
 856           this config is intended, is when reboot ends with a stalled/hung
 857           system.
 858
 859           Currently, the only fixup is for the Geode machines using
 860           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 861
 862           Say Y if you want to enable the fixup. Currently, it's safe to
 863           enable this option even if you don't need it.
 864           Say N otherwise.
 865
 866 config MICROCODE
 867         tristate "/dev/cpu/microcode - microcode support"
 868         select FW_LOADER
 869         ---help---
 870           If you say Y here, you will be able to update the microcode on
 871           certain Intel and AMD processors. The Intel support is for the
 872           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 873           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 874           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 875           You will obviously need the actual microcode binary data itself
 876           which is not shipped with the Linux kernel.
 877
 878           This option selects the general module only, you need to select
 879           at least one vendor specific module as well.
 880
 881           To compile this driver as a module, choose M here: the
 882           module will be called microcode.
 883
 884 config MICROCODE_INTEL
 885         bool "Intel microcode patch loading support"
 886         depends on MICROCODE
 887         default MICROCODE
 888         select FW_LOADER
 889         ---help---
 890           This options enables microcode patch loading support for Intel
 891           processors.
 892
 893           For latest news and information on obtaining all the required
 894           Intel ingredients for this driver, check:
 895           <http://www.urbanmyth.org/microcode/>.
 896
 897 config MICROCODE_AMD
 898         bool "AMD microcode patch loading support"
 899         depends on MICROCODE
 900         select FW_LOADER
 901         ---help---
 902           If you select this option, microcode patch loading support for AMD
 903           processors will be enabled.
 904
 905 config MICROCODE_OLD_INTERFACE
 906         def_bool y
 907         depends on MICROCODE
 908
 909 config X86_MSR
 910         tristate "/dev/cpu/*/msr - Model-specific register support"
 911         ---help---
 912           This device gives privileged processes access to the x86
 913           Model-Specific Registers (MSRs).  It is a character device with
 914           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
 915           MSR accesses are directed to a specific CPU on multi-processor
 916           systems.
 917
 918 config X86_CPUID
 919         tristate "/dev/cpu/*/cpuid - CPU information support"
 920         ---help---
 921           This device gives processes access to the x86 CPUID instruction to
 922           be executed on a specific processor.  It is a character device
 923           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
 924           /dev/cpu/31/cpuid.
 925
 926 choice
 927         prompt "High Memory Support"
 928         default HIGHMEM4G if !X86_NUMAQ
 929         default HIGHMEM64G if X86_NUMAQ
 930         depends on X86_32
 931
 932 config NOHIGHMEM
 933         bool "off"
 934         depends on !X86_NUMAQ
 935         ---help---
 936           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
 937           However, the address space of 32-bit x86 processors is only 4
 938           Gigabytes large. That means that, if you have a large amount of
 939           physical memory, not all of it can be "permanently mapped" by the
 940           kernel. The physical memory that's not permanently mapped is called
 941           "high memory".
 942
 943           If you are compiling a kernel which will never run on a machine with
 944           more than 1 Gigabyte total physical RAM, answer "off" here (default
 945           choice and suitable for most users). This will result in a "3GB/1GB"
 946           split: 3GB are mapped so that each process sees a 3GB virtual memory
 947           space and the remaining part of the 4GB virtual memory space is used
 948           by the kernel to permanently map as much physical memory as
 949           possible.
 950
 951           If the machine has between 1 and 4 Gigabytes physical RAM, then
 952           answer "4GB" here.
 953
 954           If more than 4 Gigabytes is used then answer "64GB" here. This
 955           selection turns Intel PAE (Physical Address Extension) mode on.
 956           PAE implements 3-level paging on IA32 processors. PAE is fully
 957           supported by Linux, PAE mode is implemented on all recent Intel
 958           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
 959           then the kernel will not boot on CPUs that don't support PAE!
 960
 961           The actual amount of total physical memory will either be
 962           auto detected or can be forced by using a kernel command line option
 963           such as "mem=256M". (Try "man bootparam" or see the documentation of
 964           your boot loader (lilo or loadlin) about how to pass options to the
 965           kernel at boot time.)
 966
 967           If unsure, say "off".
 968
 969 config HIGHMEM4G
 970         bool "4GB"
 971         depends on !X86_NUMAQ
 972         ---help---
 973           Select this if you have a 32-bit processor and between 1 and 4
 974           gigabytes of physical RAM.
 975
 976 config HIGHMEM64G
 977         bool "64GB"
 978         depends on !M386 && !M486
 979         select X86_PAE
 980         ---help---
 981           Select this if you have a 32-bit processor and more than 4
 982           gigabytes of physical RAM.
 983
 984 endchoice
 985
 986 choice
 987         depends on EXPERIMENTAL
 988         prompt "Memory split" if EMBEDDED
 989         default VMSPLIT_3G
 990         depends on X86_32
 991         ---help---
 992           Select the desired split between kernel and user memory.
 993
 994           If the address range available to the kernel is less than the
 995           physical memory installed, the remaining memory will be available
 996           as "high memory". Accessing high memory is a little more costly
 997           than low memory, as it needs to be mapped into the kernel first.
 998           Note that increasing the kernel address space limits the range
 999           available to user programs, making the address space there
1000           tighter.  Selecting anything other than the default 3G/1G split
1001           will also likely make your kernel incompatible with binary-only
1002           kernel modules.
1003
1004           If you are not absolutely sure what you are doing, leave this
1005           option alone!
1006
1007         config VMSPLIT_3G
1008                 bool "3G/1G user/kernel split"
1009         config VMSPLIT_3G_OPT
1010                 depends on !X86_PAE
1011                 bool "3G/1G user/kernel split (for full 1G low memory)"
1012         config VMSPLIT_2G
1013                 bool "2G/2G user/kernel split"
1014         config VMSPLIT_2G_OPT
1015                 depends on !X86_PAE
1016                 bool "2G/2G user/kernel split (for full 2G low memory)"
1017         config VMSPLIT_1G
1018                 bool "1G/3G user/kernel split"
1019 endchoice
1020
1021 config PAGE_OFFSET
1022         hex
1023         default 0xB0000000 if VMSPLIT_3G_OPT
1024         default 0x80000000 if VMSPLIT_2G
1025         default 0x78000000 if VMSPLIT_2G_OPT
1026         default 0x40000000 if VMSPLIT_1G
1027         default 0xC0000000
1028         depends on X86_32
1029
1030 config HIGHMEM
1031         def_bool y
1032         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1033
1034 config X86_PAE
1035         bool "PAE (Physical Address Extension) Support"
1036         depends on X86_32 && !HIGHMEM4G
1037         ---help---
1038           PAE is required for NX support, and furthermore enables
1039           larger swapspace support for non-overcommit purposes. It
1040           has the cost of more pagetable lookup overhead, and also
1041           consumes more pagetable space per process.
1042
1043 config ARCH_PHYS_ADDR_T_64BIT
1044         def_bool X86_64 || X86_PAE
1045
1046 config DIRECT_GBPAGES
1047         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1048         default y
1049         depends on X86_64
1050         ---help---
1051           Allow the kernel linear mapping to use 1GB pages on CPUs that
1052           support it. This can improve the kernel's performance a tiny bit by
1053           reducing TLB pressure. If in doubt, say "Y".
1054
1055 # Common NUMA Features
1056 config NUMA
1057         bool "Numa Memory Allocation and Scheduler Support"
1058         depends on SMP
1059         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1060         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1061         ---help---
1062           Enable NUMA (Non Uniform Memory Access) support.
1063
1064           The kernel will try to allocate memory used by a CPU on the
1065           local memory controller of the CPU and add some more
1066           NUMA awareness to the kernel.
1067
1068           For 64-bit this is recommended if the system is Intel Core i7
1069           (or later), AMD Opteron, or EM64T NUMA.
1070
1071           For 32-bit this is only needed on (rare) 32-bit-only platforms
1072           that support NUMA topologies, such as NUMAQ / Summit, or if you
1073           boot a 32-bit kernel on a 64-bit NUMA platform.
1074
1075           Otherwise, you should say N.
1076
1077 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1078         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1079
1080 config K8_NUMA
1081         def_bool y
1082         prompt "Old style AMD Opteron NUMA detection"
1083         depends on X86_64 && NUMA && PCI
1084         ---help---
1085           Enable K8 NUMA node topology detection.  You should say Y here if
1086           you have a multi processor AMD K8 system. This uses an old
1087           method to read the NUMA configuration directly from the builtin
1088           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1089           instead, which also takes priority if both are compiled in.
1090
1091 config X86_64_ACPI_NUMA
1092         def_bool y
1093         prompt "ACPI NUMA detection"
1094         depends on X86_64 && NUMA && ACPI && PCI
1095         select ACPI_NUMA
1096         ---help---
1097           Enable ACPI SRAT based node topology detection.
1098
1099 # Some NUMA nodes have memory ranges that span
1100 # other nodes.  Even though a pfn is valid and
1101 # between a node's start and end pfns, it may not
1102 # reside on that node.  See memmap_init_zone()
1103 # for details.
1104 config NODES_SPAN_OTHER_NODES
1105         def_bool y
1106         depends on X86_64_ACPI_NUMA
1107
1108 config NUMA_EMU
1109         bool "NUMA emulation"
1110         depends on X86_64 && NUMA
1111         ---help---
1112           Enable NUMA emulation. A flat machine will be split
1113           into virtual nodes when booted with "numa=fake=N", where N is the
1114           number of nodes. This is only useful for debugging.
1115
1116 config NODES_SHIFT
1117         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1118         range 1 9   if X86_64
1119         default "9" if MAXSMP
1120         default "6" if X86_64
1121         default "4" if X86_NUMAQ
1122         default "3"
1123         depends on NEED_MULTIPLE_NODES
1124         ---help---
1125           Specify the maximum number of NUMA Nodes available on the target
1126           system.  Increases memory reserved to accomodate various tables.
1127
1128 config HAVE_ARCH_BOOTMEM_NODE
1129         def_bool y
1130         depends on X86_32 && NUMA
1131
1132 config ARCH_HAVE_MEMORY_PRESENT
1133         def_bool y
1134         depends on X86_32 && DISCONTIGMEM
1135
1136 config NEED_NODE_MEMMAP_SIZE
1137         def_bool y
1138         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1139
1140 config HAVE_ARCH_ALLOC_REMAP
1141         def_bool y
1142         depends on X86_32 && NUMA
1143
1144 config ARCH_FLATMEM_ENABLE
1145         def_bool y
1146         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1147
1148 config ARCH_DISCONTIGMEM_ENABLE
1149         def_bool y
1150         depends on NUMA && X86_32
1151
1152 config ARCH_DISCONTIGMEM_DEFAULT
1153         def_bool y
1154         depends on NUMA && X86_32
1155
1156 config ARCH_SPARSEMEM_DEFAULT
1157         def_bool y
1158         depends on X86_64
1159
1160 config ARCH_SPARSEMEM_ENABLE
1161         def_bool y
1162         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1163         select SPARSEMEM_STATIC if X86_32
1164         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1165
1166 config ARCH_SELECT_MEMORY_MODEL
1167         def_bool y
1168         depends on ARCH_SPARSEMEM_ENABLE
1169
1170 config ARCH_MEMORY_PROBE
1171         def_bool X86_64
1172         depends on MEMORY_HOTPLUG
1173
1174 source "mm/Kconfig"
1175
1176 config HIGHPTE
1177         bool "Allocate 3rd-level pagetables from highmem"
1178         depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1179         ---help---
1180           The VM uses one page table entry for each page of physical memory.
1181           For systems with a lot of RAM, this can be wasteful of precious
1182           low memory.  Setting this option will put user-space page table
1183           entries in high memory.
1184
1185 config X86_CHECK_BIOS_CORRUPTION
1186         bool "Check for low memory corruption"
1187         ---help---
1188           Periodically check for memory corruption in low memory, which
1189           is suspected to be caused by BIOS.  Even when enabled in the
1190           configuration, it is disabled at runtime.  Enable it by
1191           setting "memory_corruption_check=1" on the kernel command
1192           line.  By default it scans the low 64k of memory every 60
1193           seconds; see the memory_corruption_check_size and
1194           memory_corruption_check_period parameters in
1195           Documentation/kernel-parameters.txt to adjust this.
1196
1197           When enabled with the default parameters, this option has
1198           almost no overhead, as it reserves a relatively small amount
1199           of memory and scans it infrequently.  It both detects corruption
1200           and prevents it from affecting the running system.
1201
1202           It is, however, intended as a diagnostic tool; if repeatable
1203           BIOS-originated corruption always affects the same memory,
1204           you can use memmap= to prevent the kernel from using that
1205           memory.
1206
1207 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1208         bool "Set the default setting of memory_corruption_check"
1209         depends on X86_CHECK_BIOS_CORRUPTION
1210         default y
1211         ---help---
1212           Set whether the default state of memory_corruption_check is
1213           on or off.
1214
1215 config X86_RESERVE_LOW_64K
1216         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1217         default y
1218         ---help---
1219           Reserve the first 64K of physical RAM on BIOSes that are known
1220           to potentially corrupt that memory range. A numbers of BIOSes are
1221           known to utilize this area during suspend/resume, so it must not
1222           be used by the kernel.
1223
1224           Set this to N if you are absolutely sure that you trust the BIOS
1225           to get all its memory reservations and usages right.
1226
1227           If you have doubts about the BIOS (e.g. suspend/resume does not
1228           work or there's kernel crashes after certain hardware hotplug
1229           events) and it's not AMI or Phoenix, then you might want to enable
1230           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1231           corruption patterns.
1232
1233           Say Y if unsure.
1234
1235 config MATH_EMULATION
1236         bool
1237         prompt "Math emulation" if X86_32
1238         ---help---
1239           Linux can emulate a math coprocessor (used for floating point
1240           operations) if you don't have one. 486DX and Pentium processors have
1241           a math coprocessor built in, 486SX and 386 do not, unless you added
1242           a 487DX or 387, respectively. (The messages during boot time can
1243           give you some hints here ["man dmesg"].) Everyone needs either a
1244           coprocessor or this emulation.
1245
1246           If you don't have a math coprocessor, you need to say Y here; if you
1247           say Y here even though you have a coprocessor, the coprocessor will
1248           be used nevertheless. (This behavior can be changed with the kernel
1249           command line option "no387", which comes handy if your coprocessor
1250           is broken. Try "man bootparam" or see the documentation of your boot
1251           loader (lilo or loadlin) about how to pass options to the kernel at
1252           boot time.) This means that it is a good idea to say Y here if you
1253           intend to use this kernel on different machines.
1254
1255           More information about the internals of the Linux math coprocessor
1256           emulation can be found in <file:arch/x86/math-emu/README>.
1257
1258           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1259           kernel, it won't hurt.
1260
1261 config MTRR
1262         bool "MTRR (Memory Type Range Register) support"
1263         ---help---
1264           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1265           the Memory Type Range Registers (MTRRs) may be used to control
1266           processor access to memory ranges. This is most useful if you have
1267           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1268           allows bus write transfers to be combined into a larger transfer
1269           before bursting over the PCI/AGP bus. This can increase performance
1270           of image write operations 2.5 times or more. Saying Y here creates a
1271           /proc/mtrr file which may be used to manipulate your processor's
1272           MTRRs. Typically the X server should use this.
1273
1274           This code has a reasonably generic interface so that similar
1275           control registers on other processors can be easily supported
1276           as well:
1277
1278           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1279           Registers (ARRs) which provide a similar functionality to MTRRs. For
1280           these, the ARRs are used to emulate the MTRRs.
1281           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1282           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1283           write-combining. All of these processors are supported by this code
1284           and it makes sense to say Y here if you have one of them.
1285
1286           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1287           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1288           can lead to all sorts of problems, so it's good to say Y here.
1289
1290           You can safely say Y even if your machine doesn't have MTRRs, you'll
1291           just add about 9 KB to your kernel.
1292
1293           See <file:Documentation/x86/mtrr.txt> for more information.
1294
1295 config MTRR_SANITIZER
1296         def_bool y
1297         prompt "MTRR cleanup support"
1298         depends on MTRR
1299         ---help---
1300           Convert MTRR layout from continuous to discrete, so X drivers can
1301           add writeback entries.
1302
1303           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1304           The largest mtrr entry size for a continous block can be set with
1305           mtrr_chunk_size.
1306
1307           If unsure, say Y.
1308
1309 config MTRR_SANITIZER_ENABLE_DEFAULT
1310         int "MTRR cleanup enable value (0-1)"
1311         range 0 1
1312         default "0"
1313         depends on MTRR_SANITIZER
1314         ---help---
1315           Enable mtrr cleanup default value
1316
1317 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1318         int "MTRR cleanup spare reg num (0-7)"
1319         range 0 7
1320         default "1"
1321         depends on MTRR_SANITIZER
1322         ---help---
1323           mtrr cleanup spare entries default, it can be changed via
1324           mtrr_spare_reg_nr=N on the kernel command line.
1325
1326 config X86_PAT
1327         bool
1328         prompt "x86 PAT support"
1329         depends on MTRR
1330         ---help---
1331           Use PAT attributes to setup page level cache control.
1332
1333           PATs are the modern equivalents of MTRRs and are much more
1334           flexible than MTRRs.
1335
1336           Say N here if you see bootup problems (boot crash, boot hang,
1337           spontaneous reboots) or a non-working video driver.
1338
1339           If unsure, say Y.
1340
1341 config EFI
1342         bool "EFI runtime service support"
1343         depends on ACPI
1344         ---help---
1345           This enables the kernel to use EFI runtime services that are
1346           available (such as the EFI variable services).
1347
1348           This option is only useful on systems that have EFI firmware.
1349           In addition, you should use the latest ELILO loader available
1350           at <http://elilo.sourceforge.net> in order to take advantage
1351           of EFI runtime services. However, even with this option, the
1352           resultant kernel should continue to boot on existing non-EFI
1353           platforms.
1354
1355 config SECCOMP
1356         def_bool y
1357         prompt "Enable seccomp to safely compute untrusted bytecode"
1358         ---help---
1359           This kernel feature is useful for number crunching applications
1360           that may need to compute untrusted bytecode during their
1361           execution. By using pipes or other transports made available to
1362           the process as file descriptors supporting the read/write
1363           syscalls, it's possible to isolate those applications in
1364           their own address space using seccomp. Once seccomp is
1365           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1366           and the task is only allowed to execute a few safe syscalls
1367           defined by each seccomp mode.
1368
1369           If unsure, say Y. Only embedded should say N here.
1370
1371 config CC_STACKPROTECTOR_ALL
1372         bool
1373
1374 config CC_STACKPROTECTOR
1375         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1376         select CC_STACKPROTECTOR_ALL
1377         ---help---
1378           This option turns on the -fstack-protector GCC feature. This
1379           feature puts, at the beginning of functions, a canary value on
1380           the stack just before the return address, and validates
1381           the value just before actually returning.  Stack based buffer
1382           overflows (that need to overwrite this return address) now also
1383           overwrite the canary, which gets detected and the attack is then
1384           neutralized via a kernel panic.
1385
1386           This feature requires gcc version 4.2 or above, or a distribution
1387           gcc with the feature backported. Older versions are automatically
1388           detected and for those versions, this configuration option is
1389           ignored. (and a warning is printed during bootup)
1390
1391 source kernel/Kconfig.hz
1392
1393 config KEXEC
1394         bool "kexec system call"
1395         ---help---
1396           kexec is a system call that implements the ability to shutdown your
1397           current kernel, and to start another kernel.  It is like a reboot
1398           but it is independent of the system firmware.   And like a reboot
1399           you can start any kernel with it, not just Linux.
1400
1401           The name comes from the similarity to the exec system call.
1402
1403           It is an ongoing process to be certain the hardware in a machine
1404           is properly shutdown, so do not be surprised if this code does not
1405           initially work for you.  It may help to enable device hotplugging
1406           support.  As of this writing the exact hardware interface is
1407           strongly in flux, so no good recommendation can be made.
1408
1409 config CRASH_DUMP
1410         bool "kernel crash dumps"
1411         depends on X86_64 || (X86_32 && HIGHMEM)
1412         ---help---
1413           Generate crash dump after being started by kexec.
1414           This should be normally only set in special crash dump kernels
1415           which are loaded in the main kernel with kexec-tools into
1416           a specially reserved region and then later executed after
1417           a crash by kdump/kexec. The crash dump kernel must be compiled
1418           to a memory address not used by the main kernel or BIOS using
1419           PHYSICAL_START, or it must be built as a relocatable image
1420           (CONFIG_RELOCATABLE=y).
1421           For more details see Documentation/kdump/kdump.txt
1422
1423 config KEXEC_JUMP
1424         bool "kexec jump (EXPERIMENTAL)"
1425         depends on EXPERIMENTAL
1426         depends on KEXEC && HIBERNATION && X86_32
1427         ---help---
1428           Jump between original kernel and kexeced kernel and invoke
1429           code in physical address mode via KEXEC
1430
1431 config PHYSICAL_START
1432         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1433         default "0x1000000" if X86_NUMAQ
1434         default "0x200000" if X86_64
1435         default "0x100000"
1436         ---help---
1437           This gives the physical address where the kernel is loaded.
1438
1439           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1440           bzImage will decompress itself to above physical address and
1441           run from there. Otherwise, bzImage will run from the address where
1442           it has been loaded by the boot loader and will ignore above physical
1443           address.
1444
1445           In normal kdump cases one does not have to set/change this option
1446           as now bzImage can be compiled as a completely relocatable image
1447           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1448           address. This option is mainly useful for the folks who don't want
1449           to use a bzImage for capturing the crash dump and want to use a
1450           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1451           to be specifically compiled to run from a specific memory area
1452           (normally a reserved region) and this option comes handy.
1453
1454           So if you are using bzImage for capturing the crash dump, leave
1455           the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1456           Otherwise if you plan to use vmlinux for capturing the crash dump
1457           change this value to start of the reserved region (Typically 16MB
1458           0x1000000). In other words, it can be set based on the "X" value as
1459           specified in the "crashkernel=YM@XM" command line boot parameter
1460           passed to the panic-ed kernel. Typically this parameter is set as
1461           crashkernel=64M@16M. Please take a look at
1462           Documentation/kdump/kdump.txt for more details about crash dumps.
1463
1464           Usage of bzImage for capturing the crash dump is recommended as
1465           one does not have to build two kernels. Same kernel can be used
1466           as production kernel and capture kernel. Above option should have
1467           gone away after relocatable bzImage support is introduced. But it
1468           is present because there are users out there who continue to use
1469           vmlinux for dump capture. This option should go away down the
1470           line.
1471
1472           Don't change this unless you know what you are doing.
1473
1474 config RELOCATABLE
1475         bool "Build a relocatable kernel (EXPERIMENTAL)"
1476         depends on EXPERIMENTAL
1477         ---help---
1478           This builds a kernel image that retains relocation information
1479           so it can be loaded someplace besides the default 1MB.
1480           The relocations tend to make the kernel binary about 10% larger,
1481           but are discarded at runtime.
1482
1483           One use is for the kexec on panic case where the recovery kernel
1484           must live at a different physical address than the primary
1485           kernel.
1486
1487           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1488           it has been loaded at and the compile time physical address
1489           (CONFIG_PHYSICAL_START) is ignored.
1490
1491 config PHYSICAL_ALIGN
1492         hex
1493         prompt "Alignment value to which kernel should be aligned" if X86_32
1494         default "0x100000" if X86_32
1495         default "0x200000" if X86_64
1496         range 0x2000 0x400000
1497         ---help---
1498           This value puts the alignment restrictions on physical address
1499           where kernel is loaded and run from. Kernel is compiled for an
1500           address which meets above alignment restriction.
1501
1502           If bootloader loads the kernel at a non-aligned address and
1503           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1504           address aligned to above value and run from there.
1505
1506           If bootloader loads the kernel at a non-aligned address and
1507           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1508           load address and decompress itself to the address it has been
1509           compiled for and run from there. The address for which kernel is
1510           compiled already meets above alignment restrictions. Hence the
1511           end result is that kernel runs from a physical address meeting
1512           above alignment restrictions.
1513
1514           Don't change this unless you know what you are doing.
1515
1516 config HOTPLUG_CPU
1517         bool "Support for hot-pluggable CPUs"
1518         depends on SMP && HOTPLUG
1519         ---help---
1520           Say Y here to allow turning CPUs off and on. CPUs can be
1521           controlled through /sys/devices/system/cpu.
1522           ( Note: power management support will enable this option
1523             automatically on SMP systems. )
1524           Say N if you want to disable CPU hotplug.
1525
1526 config COMPAT_VDSO
1527         def_bool y
1528         prompt "Compat VDSO support"
1529         depends on X86_32 || IA32_EMULATION
1530         ---help---
1531           Map the 32-bit VDSO to the predictable old-style address too.
1532         ---help---
1533           Say N here if you are running a sufficiently recent glibc
1534           version (2.3.3 or later), to remove the high-mapped
1535           VDSO mapping and to exclusively use the randomized VDSO.
1536
1537           If unsure, say Y.
1538
1539 config CMDLINE_BOOL
1540         bool "Built-in kernel command line"
1541         default n
1542         ---help---
1543           Allow for specifying boot arguments to the kernel at
1544           build time.  On some systems (e.g. embedded ones), it is
1545           necessary or convenient to provide some or all of the
1546           kernel boot arguments with the kernel itself (that is,
1547           to not rely on the boot loader to provide them.)
1548
1549           To compile command line arguments into the kernel,
1550           set this option to 'Y', then fill in the
1551           the boot arguments in CONFIG_CMDLINE.
1552
1553           Systems with fully functional boot loaders (i.e. non-embedded)
1554           should leave this option set to 'N'.
1555
1556 config CMDLINE
1557         string "Built-in kernel command string"
1558         depends on CMDLINE_BOOL
1559         default ""
1560         ---help---
1561           Enter arguments here that should be compiled into the kernel
1562           image and used at boot time.  If the boot loader provides a
1563           command line at boot time, it is appended to this string to
1564           form the full kernel command line, when the system boots.
1565
1566           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1567           change this behavior.
1568
1569           In most cases, the command line (whether built-in or provided
1570           by the boot loader) should specify the device for the root
1571           file system.
1572
1573 config CMDLINE_OVERRIDE
1574         bool "Built-in command line overrides boot loader arguments"
1575         default n
1576         depends on CMDLINE_BOOL
1577         ---help---
1578           Set this option to 'Y' to have the kernel ignore the boot loader
1579           command line, and use ONLY the built-in command line.
1580
1581           This is used to work around broken boot loaders.  This should
1582           be set to 'N' under normal conditions.
1583
1584 endmenu
1585
1586 config ARCH_ENABLE_MEMORY_HOTPLUG
1587         def_bool y
1588         depends on X86_64 || (X86_32 && HIGHMEM)
1589
1590 config ARCH_ENABLE_MEMORY_HOTREMOVE
1591         def_bool y
1592         depends on MEMORY_HOTPLUG
1593
1594 config HAVE_ARCH_EARLY_PFN_TO_NID
1595         def_bool X86_64
1596         depends on NUMA
1597
1598 menu "Power management and ACPI options"
1599
1600 config ARCH_HIBERNATION_HEADER
1601         def_bool y
1602         depends on X86_64 && HIBERNATION
1603
1604 source "kernel/power/Kconfig"
1605
1606 source "drivers/acpi/Kconfig"
1607
1608 config X86_APM_BOOT
1609         bool
1610         default y
1611         depends on APM || APM_MODULE
1612
1613 menuconfig APM
1614         tristate "APM (Advanced Power Management) BIOS support"
1615         depends on X86_32 && PM_SLEEP
1616         ---help---
1617           APM is a BIOS specification for saving power using several different
1618           techniques. This is mostly useful for battery powered laptops with
1619           APM compliant BIOSes. If you say Y here, the system time will be
1620           reset after a RESUME operation, the /proc/apm device will provide
1621           battery status information, and user-space programs will receive
1622           notification of APM "events" (e.g. battery status change).
1623
1624           If you select "Y" here, you can disable actual use of the APM
1625           BIOS by passing the "apm=off" option to the kernel at boot time.
1626
1627           Note that the APM support is almost completely disabled for
1628           machines with more than one CPU.
1629
1630           In order to use APM, you will need supporting software. For location
1631           and more information, read <file:Documentation/power/pm.txt> and the
1632           Battery Powered Linux mini-HOWTO, available from
1633           <http://www.tldp.org/docs.html#howto>.
1634
1635           This driver does not spin down disk drives (see the hdparm(8)
1636           manpage ("man 8 hdparm") for that), and it doesn't turn off
1637           VESA-compliant "green" monitors.
1638
1639           This driver does not support the TI 4000M TravelMate and the ACER
1640           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1641           desktop machines also don't have compliant BIOSes, and this driver
1642           may cause those machines to panic during the boot phase.
1643
1644           Generally, if you don't have a battery in your machine, there isn't
1645           much point in using this driver and you should say N. If you get
1646           random kernel OOPSes or reboots that don't seem to be related to
1647           anything, try disabling/enabling this option (or disabling/enabling
1648           APM in your BIOS).
1649
1650           Some other things you should try when experiencing seemingly random,
1651           "weird" problems:
1652
1653           1) make sure that you have enough swap space and that it is
1654           enabled.
1655           2) pass the "no-hlt" option to the kernel
1656           3) switch on floating point emulation in the kernel and pass
1657           the "no387" option to the kernel
1658           4) pass the "floppy=nodma" option to the kernel
1659           5) pass the "mem=4M" option to the kernel (thereby disabling
1660           all but the first 4 MB of RAM)
1661           6) make sure that the CPU is not over clocked.
1662           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1663           8) disable the cache from your BIOS settings
1664           9) install a fan for the video card or exchange video RAM
1665           10) install a better fan for the CPU
1666           11) exchange RAM chips
1667           12) exchange the motherboard.
1668
1669           To compile this driver as a module, choose M here: the
1670           module will be called apm.
1671
1672 if APM
1673
1674 config APM_IGNORE_USER_SUSPEND
1675         bool "Ignore USER SUSPEND"
1676         ---help---
1677           This option will ignore USER SUSPEND requests. On machines with a
1678           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1679           series notebooks, it is necessary to say Y because of a BIOS bug.
1680
1681 config APM_DO_ENABLE
1682         bool "Enable PM at boot time"
1683         ---help---
1684           Enable APM features at boot time. From page 36 of the APM BIOS
1685           specification: "When disabled, the APM BIOS does not automatically
1686           power manage devices, enter the Standby State, enter the Suspend
1687           State, or take power saving steps in response to CPU Idle calls."
1688           This driver will make CPU Idle calls when Linux is idle (unless this
1689           feature is turned off -- see "Do CPU IDLE calls", below). This
1690           should always save battery power, but more complicated APM features
1691           will be dependent on your BIOS implementation. You may need to turn
1692           this option off if your computer hangs at boot time when using APM
1693           support, or if it beeps continuously instead of suspending. Turn
1694           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1695           T400CDT. This is off by default since most machines do fine without
1696           this feature.
1697
1698 config APM_CPU_IDLE
1699         bool "Make CPU Idle calls when idle"
1700         ---help---
1701           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1702           On some machines, this can activate improved power savings, such as
1703           a slowed CPU clock rate, when the machine is idle. These idle calls
1704           are made after the idle loop has run for some length of time (e.g.,
1705           333 mS). On some machines, this will cause a hang at boot time or
1706           whenever the CPU becomes idle. (On machines with more than one CPU,
1707           this option does nothing.)
1708
1709 config APM_DISPLAY_BLANK
1710         bool "Enable console blanking using APM"
1711         ---help---
1712           Enable console blanking using the APM. Some laptops can use this to
1713           turn off the LCD backlight when the screen blanker of the Linux
1714           virtual console blanks the screen. Note that this is only used by
1715           the virtual console screen blanker, and won't turn off the backlight
1716           when using the X Window system. This also doesn't have anything to
1717           do with your VESA-compliant power-saving monitor. Further, this
1718           option doesn't work for all laptops -- it might not turn off your
1719           backlight at all, or it might print a lot of errors to the console,
1720           especially if you are using gpm.
1721
1722 config APM_ALLOW_INTS
1723         bool "Allow interrupts during APM BIOS calls"
1724         ---help---
1725           Normally we disable external interrupts while we are making calls to
1726           the APM BIOS as a measure to lessen the effects of a badly behaving
1727           BIOS implementation.  The BIOS should reenable interrupts if it
1728           needs to.  Unfortunately, some BIOSes do not -- especially those in
1729           many of the newer IBM Thinkpads.  If you experience hangs when you
1730           suspend, try setting this to Y.  Otherwise, say N.
1731
1732 endif # APM
1733
1734 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1735
1736 source "drivers/cpuidle/Kconfig"
1737
1738 source "drivers/idle/Kconfig"
1739
1740 endmenu
1741
1742
1743 menu "Bus options (PCI etc.)"
1744
1745 config PCI
1746         bool "PCI support"
1747         default y
1748         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1749         ---help---
1750           Find out whether you have a PCI motherboard. PCI is the name of a
1751           bus system, i.e. the way the CPU talks to the other stuff inside
1752           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1753           VESA. If you have PCI, say Y, otherwise N.
1754
1755 choice
1756         prompt "PCI access mode"
1757         depends on X86_32 && PCI
1758         default PCI_GOANY
1759         ---help---
1760           On PCI systems, the BIOS can be used to detect the PCI devices and
1761           determine their configuration. However, some old PCI motherboards
1762           have BIOS bugs and may crash if this is done. Also, some embedded
1763           PCI-based systems don't have any BIOS at all. Linux can also try to
1764           detect the PCI hardware directly without using the BIOS.
1765
1766           With this option, you can specify how Linux should detect the
1767           PCI devices. If you choose "BIOS", the BIOS will be used,
1768           if you choose "Direct", the BIOS won't be used, and if you
1769           choose "MMConfig", then PCI Express MMCONFIG will be used.
1770           If you choose "Any", the kernel will try MMCONFIG, then the
1771           direct access method and falls back to the BIOS if that doesn't
1772           work. If unsure, go with the default, which is "Any".
1773
1774 config PCI_GOBIOS
1775         bool "BIOS"
1776
1777 config PCI_GOMMCONFIG
1778         bool "MMConfig"
1779
1780 config PCI_GODIRECT
1781         bool "Direct"
1782
1783 config PCI_GOOLPC
1784         bool "OLPC"
1785         depends on OLPC
1786
1787 config PCI_GOANY
1788         bool "Any"
1789
1790 endchoice
1791
1792 config PCI_BIOS
1793         def_bool y
1794         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1795
1796 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1797 config PCI_DIRECT
1798         def_bool y
1799         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1800
1801 config PCI_MMCONFIG
1802         def_bool y
1803         depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1804
1805 config PCI_OLPC
1806         def_bool y
1807         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1808
1809 config PCI_DOMAINS
1810         def_bool y
1811         depends on PCI
1812
1813 config PCI_MMCONFIG
1814         bool "Support mmconfig PCI config space access"
1815         depends on X86_64 && PCI && ACPI
1816
1817 config DMAR
1818         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1819         depends on X86_64 && PCI_MSI && ACPI && EXPERIMENTAL
1820         ---help---
1821           DMA remapping (DMAR) devices support enables independent address
1822           translations for Direct Memory Access (DMA) from devices.
1823           These DMA remapping devices are reported via ACPI tables
1824           and include PCI device scope covered by these DMA
1825           remapping devices.
1826
1827 config DMAR_DEFAULT_ON
1828         def_bool y
1829         prompt "Enable DMA Remapping Devices by default"
1830         depends on DMAR
1831         help
1832           Selecting this option will enable a DMAR device at boot time if
1833           one is found. If this option is not selected, DMAR support can
1834           be enabled by passing intel_iommu=on to the kernel. It is
1835           recommended you say N here while the DMAR code remains
1836           experimental.
1837
1838 config DMAR_GFX_WA
1839         def_bool y
1840         prompt "Support for Graphics workaround"
1841         depends on DMAR
1842         ---help---
1843           Current Graphics drivers tend to use physical address
1844           for DMA and avoid using DMA APIs. Setting this config
1845           option permits the IOMMU driver to set a unity map for
1846           all the OS-visible memory. Hence the driver can continue
1847           to use physical addresses for DMA.
1848
1849 config DMAR_FLOPPY_WA
1850         def_bool y
1851         depends on DMAR
1852         ---help---
1853           Floppy disk drivers are know to bypass DMA API calls
1854           thereby failing to work when IOMMU is enabled. This
1855           workaround will setup a 1:1 mapping for the first
1856           16M to make floppy (an ISA device) work.
1857
1858 config INTR_REMAP
1859         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1860         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1861         select X86_X2APIC
1862         ---help---
1863           Supports Interrupt remapping for IO-APIC and MSI devices.
1864           To use x2apic mode in the CPU's which support x2APIC enhancements or
1865           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1866
1867 source "drivers/pci/pcie/Kconfig"
1868
1869 source "drivers/pci/Kconfig"
1870
1871 # x86_64 have no ISA slots, but do have ISA-style DMA.
1872 config ISA_DMA_API
1873         def_bool y
1874
1875 if X86_32
1876
1877 config ISA
1878         bool "ISA support"
1879         ---help---
1880           Find out whether you have ISA slots on your motherboard.  ISA is the
1881           name of a bus system, i.e. the way the CPU talks to the other stuff
1882           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1883           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1884           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1885
1886 config EISA
1887         bool "EISA support"
1888         depends on ISA
1889         ---help---
1890           The Extended Industry Standard Architecture (EISA) bus was
1891           developed as an open alternative to the IBM MicroChannel bus.
1892
1893           The EISA bus provided some of the features of the IBM MicroChannel
1894           bus while maintaining backward compatibility with cards made for
1895           the older ISA bus.  The EISA bus saw limited use between 1988 and
1896           1995 when it was made obsolete by the PCI bus.
1897
1898           Say Y here if you are building a kernel for an EISA-based machine.
1899
1900           Otherwise, say N.
1901
1902 source "drivers/eisa/Kconfig"
1903
1904 config MCA
1905         bool "MCA support"
1906         ---help---
1907           MicroChannel Architecture is found in some IBM PS/2 machines and
1908           laptops.  It is a bus system similar to PCI or ISA. See
1909           <file:Documentation/mca.txt> (and especially the web page given
1910           there) before attempting to build an MCA bus kernel.
1911
1912 source "drivers/mca/Kconfig"
1913
1914 config SCx200
1915         tristate "NatSemi SCx200 support"
1916         ---help---
1917           This provides basic support for National Semiconductor's
1918           (now AMD's) Geode processors.  The driver probes for the
1919           PCI-IDs of several on-chip devices, so its a good dependency
1920           for other scx200_* drivers.
1921
1922           If compiled as a module, the driver is named scx200.
1923
1924 config SCx200HR_TIMER
1925         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1926         depends on SCx200 && GENERIC_TIME
1927         default y
1928         ---help---
1929           This driver provides a clocksource built upon the on-chip
1930           27MHz high-resolution timer.  Its also a workaround for
1931           NSC Geode SC-1100's buggy TSC, which loses time when the
1932           processor goes idle (as is done by the scheduler).  The
1933           other workaround is idle=poll boot option.
1934
1935 config GEODE_MFGPT_TIMER
1936         def_bool y
1937         prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1938         depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1939         ---help---
1940           This driver provides a clock event source based on the MFGPT
1941           timer(s) in the CS5535 and CS5536 companion chip for the geode.
1942           MFGPTs have a better resolution and max interval than the
1943           generic PIT, and are suitable for use as high-res timers.
1944
1945 config OLPC
1946         bool "One Laptop Per Child support"
1947         default n
1948         ---help---
1949           Add support for detecting the unique features of the OLPC
1950           XO hardware.
1951
1952 endif # X86_32
1953
1954 config K8_NB
1955         def_bool y
1956         depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1957
1958 source "drivers/pcmcia/Kconfig"
1959
1960 source "drivers/pci/hotplug/Kconfig"
1961
1962 endmenu
1963
1964
1965 menu "Executable file formats / Emulations"
1966
1967 source "fs/Kconfig.binfmt"
1968
1969 config IA32_EMULATION
1970         bool "IA32 Emulation"
1971         depends on X86_64
1972         select COMPAT_BINFMT_ELF
1973         ---help---
1974           Include code to run 32-bit programs under a 64-bit kernel. You should
1975           likely turn this on, unless you're 100% sure that you don't have any
1976           32-bit programs left.
1977
1978 config IA32_AOUT
1979         tristate "IA32 a.out support"
1980         depends on IA32_EMULATION
1981         ---help---
1982           Support old a.out binaries in the 32bit emulation.
1983
1984 config COMPAT
1985         def_bool y
1986         depends on IA32_EMULATION
1987
1988 config COMPAT_FOR_U64_ALIGNMENT
1989         def_bool COMPAT
1990         depends on X86_64
1991
1992 config SYSVIPC_COMPAT
1993         def_bool y
1994         depends on COMPAT && SYSVIPC
1995
1996 endmenu
1997
1998
1999 config HAVE_ATOMIC_IOMAP
2000         def_bool y
2001         depends on X86_32
2002
2003 source "net/Kconfig"
2004
2005 source "drivers/Kconfig"
2006
2007 source "drivers/firmware/Kconfig"
2008
2009 source "fs/Kconfig"
2010
2011 source "arch/x86/Kconfig.debug"
2012
2013 source "security/Kconfig"
2014
2015 source "crypto/Kconfig"
2016
2017 source "arch/x86/kvm/Kconfig"
2018
2019 source "lib/Kconfig"