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_PERF_EVENTS if (!M386 && !M486)
  28         select HAVE_IOREMAP_PROT
  29         select HAVE_KPROBES
  30         select ARCH_WANT_OPTIONAL_GPIOLIB
  31         select ARCH_WANT_FRAME_POINTERS
  32         select HAVE_DMA_ATTRS
  33         select HAVE_KRETPROBES
  34         select HAVE_FTRACE_MCOUNT_RECORD
  35         select HAVE_DYNAMIC_FTRACE
  36         select HAVE_FUNCTION_TRACER
  37         select HAVE_FUNCTION_GRAPH_TRACER
  38         select HAVE_FUNCTION_GRAPH_FP_TEST
  39         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  40         select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  41         select HAVE_SYSCALL_TRACEPOINTS
  42         select HAVE_KVM
  43         select HAVE_ARCH_KGDB
  44         select HAVE_ARCH_TRACEHOOK
  45         select HAVE_GENERIC_DMA_COHERENT if X86_32
  46         select HAVE_EFFICIENT_UNALIGNED_ACCESS
  47         select USER_STACKTRACE_SUPPORT
  48         select HAVE_DMA_API_DEBUG
  49         select HAVE_KERNEL_GZIP
  50         select HAVE_KERNEL_BZIP2
  51         select HAVE_KERNEL_LZMA
  52         select HAVE_HW_BREAKPOINT
  53         select HAVE_ARCH_KMEMCHECK
  54         select HAVE_USER_RETURN_NOTIFIER
  55
  56 config OUTPUT_FORMAT
  57         string
  58         default "elf32-i386" if X86_32
  59         default "elf64-x86-64" if X86_64
  60
  61 config ARCH_DEFCONFIG
  62         string
  63         default "arch/x86/configs/i386_defconfig" if X86_32
  64         default "arch/x86/configs/x86_64_defconfig" if X86_64
  65
  66 config GENERIC_TIME
  67         def_bool y
  68
  69 config GENERIC_CMOS_UPDATE
  70         def_bool y
  71
  72 config CLOCKSOURCE_WATCHDOG
  73         def_bool y
  74
  75 config GENERIC_CLOCKEVENTS
  76         def_bool y
  77
  78 config GENERIC_CLOCKEVENTS_BROADCAST
  79         def_bool y
  80         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  81
  82 config LOCKDEP_SUPPORT
  83         def_bool y
  84
  85 config STACKTRACE_SUPPORT
  86         def_bool y
  87
  88 config HAVE_LATENCYTOP_SUPPORT
  89         def_bool y
  90
  91 config MMU
  92         def_bool y
  93
  94 config ZONE_DMA
  95         def_bool y
  96
  97 config SBUS
  98         bool
  99
 100 config GENERIC_ISA_DMA
 101         def_bool y
 102
 103 config GENERIC_IOMAP
 104         def_bool y
 105
 106 config GENERIC_BUG
 107         def_bool y
 108         depends on BUG
 109         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 110
 111 config GENERIC_BUG_RELATIVE_POINTERS
 112         bool
 113
 114 config GENERIC_HWEIGHT
 115         def_bool y
 116
 117 config GENERIC_GPIO
 118         bool
 119
 120 config ARCH_MAY_HAVE_PC_FDC
 121         def_bool y
 122
 123 config RWSEM_GENERIC_SPINLOCK
 124         def_bool !X86_XADD
 125
 126 config RWSEM_XCHGADD_ALGORITHM
 127         def_bool X86_XADD
 128
 129 config ARCH_HAS_CPU_IDLE_WAIT
 130         def_bool y
 131
 132 config GENERIC_CALIBRATE_DELAY
 133         def_bool y
 134
 135 config GENERIC_TIME_VSYSCALL
 136         bool
 137         default X86_64
 138
 139 config ARCH_HAS_CPU_RELAX
 140         def_bool y
 141
 142 config ARCH_HAS_DEFAULT_IDLE
 143         def_bool y
 144
 145 config ARCH_HAS_CACHE_LINE_SIZE
 146         def_bool y
 147
 148 config HAVE_SETUP_PER_CPU_AREA
 149         def_bool y
 150
 151 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 152         def_bool y
 153
 154 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 155         def_bool y
 156
 157 config HAVE_CPUMASK_OF_CPU_MAP
 158         def_bool X86_64_SMP
 159
 160 config ARCH_HIBERNATION_POSSIBLE
 161         def_bool y
 162
 163 config ARCH_SUSPEND_POSSIBLE
 164         def_bool y
 165
 166 config ZONE_DMA32
 167         bool
 168         default X86_64
 169
 170 config ARCH_POPULATES_NODE_MAP
 171         def_bool y
 172
 173 config AUDIT_ARCH
 174         bool
 175         default X86_64
 176
 177 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 178         def_bool y
 179
 180 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 181         def_bool y
 182
 183 config HAVE_INTEL_TXT
 184         def_bool y
 185         depends on EXPERIMENTAL && DMAR && ACPI
 186
 187 # Use the generic interrupt handling code in kernel/irq/:
 188 config GENERIC_HARDIRQS
 189         bool
 190         default y
 191
 192 config GENERIC_HARDIRQS_NO__DO_IRQ
 193        def_bool y
 194
 195 config GENERIC_IRQ_PROBE
 196         bool
 197         default y
 198
 199 config GENERIC_PENDING_IRQ
 200         bool
 201         depends on GENERIC_HARDIRQS && SMP
 202         default y
 203
 204 config USE_GENERIC_SMP_HELPERS
 205         def_bool y
 206         depends on SMP
 207
 208 config X86_32_SMP
 209         def_bool y
 210         depends on X86_32 && SMP
 211
 212 config X86_64_SMP
 213         def_bool y
 214         depends on X86_64 && SMP
 215
 216 config X86_HT
 217         bool
 218         depends on SMP
 219         default y
 220
 221 config X86_TRAMPOLINE
 222         bool
 223         depends on SMP || (64BIT && ACPI_SLEEP)
 224         default y
 225
 226 config X86_32_LAZY_GS
 227         def_bool y
 228         depends on X86_32 && !CC_STACKPROTECTOR
 229
 230 config KTIME_SCALAR
 231         def_bool X86_32
 232 source "init/Kconfig"
 233 source "kernel/Kconfig.freezer"
 234
 235 menu "Processor type and features"
 236
 237 source "kernel/time/Kconfig"
 238
 239 config SMP
 240         bool "Symmetric multi-processing support"
 241         ---help---
 242           This enables support for systems with more than one CPU. If you have
 243           a system with only one CPU, like most personal computers, say N. If
 244           you have a system with more than one CPU, say Y.
 245
 246           If you say N here, the kernel will run on single and multiprocessor
 247           machines, but will use only one CPU of a multiprocessor machine. If
 248           you say Y here, the kernel will run on many, but not all,
 249           singleprocessor machines. On a singleprocessor machine, the kernel
 250           will run faster if you say N here.
 251
 252           Note that if you say Y here and choose architecture "586" or
 253           "Pentium" under "Processor family", the kernel will not work on 486
 254           architectures. Similarly, multiprocessor kernels for the "PPro"
 255           architecture may not work on all Pentium based boards.
 256
 257           People using multiprocessor machines who say Y here should also say
 258           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 259           Management" code will be disabled if you say Y here.
 260
 261           See also <file:Documentation/i386/IO-APIC.txt>,
 262           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 263           <http://www.tldp.org/docs.html#howto>.
 264
 265           If you don't know what to do here, say N.
 266
 267 config X86_X2APIC
 268         bool "Support x2apic"
 269         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 270         ---help---
 271           This enables x2apic support on CPUs that have this feature.
 272
 273           This allows 32-bit apic IDs (so it can support very large systems),
 274           and accesses the local apic via MSRs not via mmio.
 275
 276           If you don't know what to do here, say N.
 277
 278 config SPARSE_IRQ
 279         bool "Support sparse irq numbering"
 280         depends on PCI_MSI || HT_IRQ
 281         ---help---
 282           This enables support for sparse irqs. This is useful for distro
 283           kernels that want to define a high CONFIG_NR_CPUS value but still
 284           want to have low kernel memory footprint on smaller machines.
 285
 286           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 287             out the irq_desc[] array in a more NUMA-friendly way. )
 288
 289           If you don't know what to do here, say N.
 290
 291 config NUMA_IRQ_DESC
 292         def_bool y
 293         depends on SPARSE_IRQ && NUMA
 294
 295 config X86_MPPARSE
 296         bool "Enable MPS table" if ACPI
 297         default y
 298         depends on X86_LOCAL_APIC
 299         ---help---
 300           For old smp systems that do not have proper acpi support. Newer systems
 301           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 302
 303 config X86_BIGSMP
 304         bool "Support for big SMP systems with more than 8 CPUs"
 305         depends on X86_32 && SMP
 306         ---help---
 307           This option is needed for the systems that have more than 8 CPUs
 308
 309 if X86_32
 310 config X86_EXTENDED_PLATFORM
 311         bool "Support for extended (non-PC) x86 platforms"
 312         default y
 313         ---help---
 314           If you disable this option then the kernel will only support
 315           standard PC platforms. (which covers the vast majority of
 316           systems out there.)
 317
 318           If you enable this option then you'll be able to select support
 319           for the following (non-PC) 32 bit x86 platforms:
 320                 AMD Elan
 321                 NUMAQ (IBM/Sequent)
 322                 RDC R-321x SoC
 323                 SGI 320/540 (Visual Workstation)
 324                 Summit/EXA (IBM x440)
 325                 Unisys ES7000 IA32 series
 326                 Moorestown MID devices
 327
 328           If you have one of these systems, or if you want to build a
 329           generic distribution kernel, say Y here - otherwise say N.
 330 endif
 331
 332 if X86_64
 333 config X86_EXTENDED_PLATFORM
 334         bool "Support for extended (non-PC) x86 platforms"
 335         default y
 336         ---help---
 337           If you disable this option then the kernel will only support
 338           standard PC platforms. (which covers the vast majority of
 339           systems out there.)
 340
 341           If you enable this option then you'll be able to select support
 342           for the following (non-PC) 64 bit x86 platforms:
 343                 ScaleMP vSMP
 344                 SGI Ultraviolet
 345
 346           If you have one of these systems, or if you want to build a
 347           generic distribution kernel, say Y here - otherwise say N.
 348 endif
 349 # This is an alphabetically sorted list of 64 bit extended platforms
 350 # Please maintain the alphabetic order if and when there are additions
 351
 352 config X86_VSMP
 353         bool "ScaleMP vSMP"
 354         select PARAVIRT
 355         depends on X86_64 && PCI
 356         depends on X86_EXTENDED_PLATFORM
 357         ---help---
 358           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 359           supposed to run on these EM64T-based machines.  Only choose this option
 360           if you have one of these machines.
 361
 362 config X86_UV
 363         bool "SGI Ultraviolet"
 364         depends on X86_64
 365         depends on X86_EXTENDED_PLATFORM
 366         depends on NUMA
 367         depends on X86_X2APIC
 368         ---help---
 369           This option is needed in order to support SGI Ultraviolet systems.
 370           If you don't have one of these, you should say N here.
 371
 372 # Following is an alphabetically sorted list of 32 bit extended platforms
 373 # Please maintain the alphabetic order if and when there are additions
 374
 375 config X86_ELAN
 376         bool "AMD Elan"
 377         depends on X86_32
 378         depends on X86_EXTENDED_PLATFORM
 379         ---help---
 380           Select this for an AMD Elan processor.
 381
 382           Do not use this option for K6/Athlon/Opteron processors!
 383
 384           If unsure, choose "PC-compatible" instead.
 385
 386 config X86_MRST
 387        bool "Moorestown MID platform"
 388         depends on X86_32
 389         depends on X86_EXTENDED_PLATFORM
 390         ---help---
 391           Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 392           Internet Device(MID) platform. Moorestown consists of two chips:
 393           Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
 394           Unlike standard x86 PCs, Moorestown does not have many legacy devices
 395           nor standard legacy replacement devices/features. e.g. Moorestown does
 396           not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
 397
 398 config X86_RDC321X
 399         bool "RDC R-321x SoC"
 400         depends on X86_32
 401         depends on X86_EXTENDED_PLATFORM
 402         select M486
 403         select X86_REBOOTFIXUPS
 404         ---help---
 405           This option is needed for RDC R-321x system-on-chip, also known
 406           as R-8610-(G).
 407           If you don't have one of these chips, you should say N here.
 408
 409 config X86_32_NON_STANDARD
 410         bool "Support non-standard 32-bit SMP architectures"
 411         depends on X86_32 && SMP
 412         depends on X86_EXTENDED_PLATFORM
 413         ---help---
 414           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 415           subarchitectures.  It is intended for a generic binary kernel.
 416           if you select them all, kernel will probe it one by one. and will
 417           fallback to default.
 418
 419 # Alphabetically sorted list of Non standard 32 bit platforms
 420
 421 config X86_NUMAQ
 422         bool "NUMAQ (IBM/Sequent)"
 423         depends on X86_32_NON_STANDARD
 424         select NUMA
 425         select X86_MPPARSE
 426         ---help---
 427           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 428           NUMA multiquad box. This changes the way that processors are
 429           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 430           of Flat Logical.  You will need a new lynxer.elf file to flash your
 431           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 432
 433 config X86_SUPPORTS_MEMORY_FAILURE
 434         bool
 435         # MCE code calls memory_failure():
 436         depends on X86_MCE
 437         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
 438         depends on !X86_NUMAQ
 439         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
 440         depends on X86_64 || !SPARSEMEM
 441         select ARCH_SUPPORTS_MEMORY_FAILURE
 442         default y
 443
 444 config X86_VISWS
 445         bool "SGI 320/540 (Visual Workstation)"
 446         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 447         depends on X86_32_NON_STANDARD
 448         ---help---
 449           The SGI Visual Workstation series is an IA32-based workstation
 450           based on SGI systems chips with some legacy PC hardware attached.
 451
 452           Say Y here to create a kernel to run on the SGI 320 or 540.
 453
 454           A kernel compiled for the Visual Workstation will run on general
 455           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 456
 457 config X86_SUMMIT
 458         bool "Summit/EXA (IBM x440)"
 459         depends on X86_32_NON_STANDARD
 460         ---help---
 461           This option is needed for IBM systems that use the Summit/EXA chipset.
 462           In particular, it is needed for the x440.
 463
 464 config X86_ES7000
 465         bool "Unisys ES7000 IA32 series"
 466         depends on X86_32_NON_STANDARD && X86_BIGSMP
 467         ---help---
 468           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 469           supposed to run on an IA32-based Unisys ES7000 system.
 470
 471 config SCHED_OMIT_FRAME_POINTER
 472         def_bool y
 473         prompt "Single-depth WCHAN output"
 474         depends on X86
 475         ---help---
 476           Calculate simpler /proc/<PID>/wchan values. If this option
 477           is disabled then wchan values will recurse back to the
 478           caller function. This provides more accurate wchan values,
 479           at the expense of slightly more scheduling overhead.
 480
 481           If in doubt, say "Y".
 482
 483 menuconfig PARAVIRT_GUEST
 484         bool "Paravirtualized guest support"
 485         ---help---
 486           Say Y here to get to see options related to running Linux under
 487           various hypervisors.  This option alone does not add any kernel code.
 488
 489           If you say N, all options in this submenu will be skipped and disabled.
 490
 491 if PARAVIRT_GUEST
 492
 493 source "arch/x86/xen/Kconfig"
 494
 495 config VMI
 496         bool "VMI Guest support (DEPRECATED)"
 497         select PARAVIRT
 498         depends on X86_32
 499         ---help---
 500           VMI provides a paravirtualized interface to the VMware ESX server
 501           (it could be used by other hypervisors in theory too, but is not
 502           at the moment), by linking the kernel to a GPL-ed ROM module
 503           provided by the hypervisor.
 504
 505           As of September 2009, VMware has started a phased retirement
 506           of this feature from VMware's products. Please see
 507           feature-removal-schedule.txt for details.  If you are
 508           planning to enable this option, please note that you cannot
 509           live migrate a VMI enabled VM to a future VMware product,
 510           which doesn't support VMI. So if you expect your kernel to
 511           seamlessly migrate to newer VMware products, keep this
 512           disabled.
 513
 514 config KVM_CLOCK
 515         bool "KVM paravirtualized clock"
 516         select PARAVIRT
 517         select PARAVIRT_CLOCK
 518         ---help---
 519           Turning on this option will allow you to run a paravirtualized clock
 520           when running over the KVM hypervisor. Instead of relying on a PIT
 521           (or probably other) emulation by the underlying device model, the host
 522           provides the guest with timing infrastructure such as time of day, and
 523           system time
 524
 525 config KVM_GUEST
 526         bool "KVM Guest support"
 527         select PARAVIRT
 528         ---help---
 529           This option enables various optimizations for running under the KVM
 530           hypervisor.
 531
 532 source "arch/x86/lguest/Kconfig"
 533
 534 config PARAVIRT
 535         bool "Enable paravirtualization code"
 536         ---help---
 537           This changes the kernel so it can modify itself when it is run
 538           under a hypervisor, potentially improving performance significantly
 539           over full virtualization.  However, when run without a hypervisor
 540           the kernel is theoretically slower and slightly larger.
 541
 542 config PARAVIRT_SPINLOCKS
 543         bool "Paravirtualization layer for spinlocks"
 544         depends on PARAVIRT && SMP && EXPERIMENTAL
 545         ---help---
 546           Paravirtualized spinlocks allow a pvops backend to replace the
 547           spinlock implementation with something virtualization-friendly
 548           (for example, block the virtual CPU rather than spinning).
 549
 550           Unfortunately the downside is an up to 5% performance hit on
 551           native kernels, with various workloads.
 552
 553           If you are unsure how to answer this question, answer N.
 554
 555 config PARAVIRT_CLOCK
 556         bool
 557         default n
 558
 559 endif
 560
 561 config PARAVIRT_DEBUG
 562         bool "paravirt-ops debugging"
 563         depends on PARAVIRT && DEBUG_KERNEL
 564         ---help---
 565           Enable to debug paravirt_ops internals.  Specifically, BUG if
 566           a paravirt_op is missing when it is called.
 567
 568 config MEMTEST
 569         bool "Memtest"
 570         ---help---
 571           This option adds a kernel parameter 'memtest', which allows memtest
 572           to be set.
 573                 memtest=0, mean disabled; -- default
 574                 memtest=1, mean do 1 test pattern;
 575                 ...
 576                 memtest=4, mean do 4 test patterns.
 577           If you are unsure how to answer this question, answer N.
 578
 579 config X86_SUMMIT_NUMA
 580         def_bool y
 581         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 582
 583 config X86_CYCLONE_TIMER
 584         def_bool y
 585         depends on X86_32_NON_STANDARD
 586
 587 source "arch/x86/Kconfig.cpu"
 588
 589 config HPET_TIMER
 590         def_bool X86_64
 591         prompt "HPET Timer Support" if X86_32
 592         ---help---
 593           Use the IA-PC HPET (High Precision Event Timer) to manage
 594           time in preference to the PIT and RTC, if a HPET is
 595           present.
 596           HPET is the next generation timer replacing legacy 8254s.
 597           The HPET provides a stable time base on SMP
 598           systems, unlike the TSC, but it is more expensive to access,
 599           as it is off-chip.  You can find the HPET spec at
 600           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 601
 602           You can safely choose Y here.  However, HPET will only be
 603           activated if the platform and the BIOS support this feature.
 604           Otherwise the 8254 will be used for timing services.
 605
 606           Choose N to continue using the legacy 8254 timer.
 607
 608 config HPET_EMULATE_RTC
 609         def_bool y
 610         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 611
 612 # Mark as embedded because too many people got it wrong.
 613 # The code disables itself when not needed.
 614 config DMI
 615         default y
 616         bool "Enable DMI scanning" if EMBEDDED
 617         ---help---
 618           Enabled scanning of DMI to identify machine quirks. Say Y
 619           here unless you have verified that your setup is not
 620           affected by entries in the DMI blacklist. Required by PNP
 621           BIOS code.
 622
 623 config GART_IOMMU
 624         bool "GART IOMMU support" if EMBEDDED
 625         default y
 626         select SWIOTLB
 627         depends on X86_64 && PCI
 628         ---help---
 629           Support for full DMA access of devices with 32bit memory access only
 630           on systems with more than 3GB. This is usually needed for USB,
 631           sound, many IDE/SATA chipsets and some other devices.
 632           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 633           based hardware IOMMU and a software bounce buffer based IOMMU used
 634           on Intel systems and as fallback.
 635           The code is only active when needed (enough memory and limited
 636           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 637           too.
 638
 639 config CALGARY_IOMMU
 640         bool "IBM Calgary IOMMU support"
 641         select SWIOTLB
 642         depends on X86_64 && PCI && EXPERIMENTAL
 643         ---help---
 644           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 645           systems. Needed to run systems with more than 3GB of memory
 646           properly with 32-bit PCI devices that do not support DAC
 647           (Double Address Cycle). Calgary also supports bus level
 648           isolation, where all DMAs pass through the IOMMU.  This
 649           prevents them from going anywhere except their intended
 650           destination. This catches hard-to-find kernel bugs and
 651           mis-behaving drivers and devices that do not use the DMA-API
 652           properly to set up their DMA buffers.  The IOMMU can be
 653           turned off at boot time with the iommu=off parameter.
 654           Normally the kernel will make the right choice by itself.
 655           If unsure, say Y.
 656
 657 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 658         def_bool y
 659         prompt "Should Calgary be enabled by default?"
 660         depends on CALGARY_IOMMU
 661         ---help---
 662           Should Calgary be enabled by default? if you choose 'y', Calgary
 663           will be used (if it exists). If you choose 'n', Calgary will not be
 664           used even if it exists. If you choose 'n' and would like to use
 665           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 666           If unsure, say Y.
 667
 668 config AMD_IOMMU
 669         bool "AMD IOMMU support"
 670         select SWIOTLB
 671         select PCI_MSI
 672         depends on X86_64 && PCI && ACPI
 673         ---help---
 674           With this option you can enable support for AMD IOMMU hardware in
 675           your system. An IOMMU is a hardware component which provides
 676           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 677           can isolate the the DMA memory of different devices and protect the
 678           system from misbehaving device drivers or hardware.
 679
 680           You can find out if your system has an AMD IOMMU if you look into
 681           your BIOS for an option to enable it or if you have an IVRS ACPI
 682           table.
 683
 684 config AMD_IOMMU_STATS
 685         bool "Export AMD IOMMU statistics to debugfs"
 686         depends on AMD_IOMMU
 687         select DEBUG_FS
 688         ---help---
 689           This option enables code in the AMD IOMMU driver to collect various
 690           statistics about whats happening in the driver and exports that
 691           information to userspace via debugfs.
 692           If unsure, say N.
 693
 694 # need this always selected by IOMMU for the VIA workaround
 695 config SWIOTLB
 696         def_bool y if X86_64
 697         ---help---
 698           Support for software bounce buffers used on x86-64 systems
 699           which don't have a hardware IOMMU (e.g. the current generation
 700           of Intel's x86-64 CPUs). Using this PCI devices which can only
 701           access 32-bits of memory can be used on systems with more than
 702           3 GB of memory. If unsure, say Y.
 703
 704 config IOMMU_HELPER
 705         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 706
 707 config IOMMU_API
 708         def_bool (AMD_IOMMU || DMAR)
 709
 710 config MAXSMP
 711         bool "Configure Maximum number of SMP Processors and NUMA Nodes"
 712         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 713         select CPUMASK_OFFSTACK
 714         default n
 715         ---help---
 716           Configure maximum number of CPUS and NUMA Nodes for this architecture.
 717           If unsure, say N.
 718
 719 config NR_CPUS
 720         int "Maximum number of CPUs" if SMP && !MAXSMP
 721         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 722         range 2 512 if SMP && !MAXSMP
 723         default "1" if !SMP
 724         default "4096" if MAXSMP
 725         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 726         default "8" if SMP
 727         ---help---
 728           This allows you to specify the maximum number of CPUs which this
 729           kernel will support.  The maximum supported value is 512 and the
 730           minimum value which makes sense is 2.
 731
 732           This is purely to save memory - each supported CPU adds
 733           approximately eight kilobytes to the kernel image.
 734
 735 config SCHED_SMT
 736         bool "SMT (Hyperthreading) scheduler support"
 737         depends on X86_HT
 738         ---help---
 739           SMT scheduler support improves the CPU scheduler's decision making
 740           when dealing with Intel Pentium 4 chips with HyperThreading at a
 741           cost of slightly increased overhead in some places. If unsure say
 742           N here.
 743
 744 config SCHED_MC
 745         def_bool y
 746         prompt "Multi-core scheduler support"
 747         depends on X86_HT
 748         ---help---
 749           Multi-core scheduler support improves the CPU scheduler's decision
 750           making when dealing with multi-core CPU chips at a cost of slightly
 751           increased overhead in some places. If unsure say N here.
 752
 753 source "kernel/Kconfig.preempt"
 754
 755 config X86_UP_APIC
 756         bool "Local APIC support on uniprocessors"
 757         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 758         ---help---
 759           A local APIC (Advanced Programmable Interrupt Controller) is an
 760           integrated interrupt controller in the CPU. If you have a single-CPU
 761           system which has a processor with a local APIC, you can say Y here to
 762           enable and use it. If you say Y here even though your machine doesn't
 763           have a local APIC, then the kernel will still run with no slowdown at
 764           all. The local APIC supports CPU-generated self-interrupts (timer,
 765           performance counters), and the NMI watchdog which detects hard
 766           lockups.
 767
 768 config X86_UP_IOAPIC
 769         bool "IO-APIC support on uniprocessors"
 770         depends on X86_UP_APIC
 771         ---help---
 772           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 773           SMP-capable replacement for PC-style interrupt controllers. Most
 774           SMP systems and many recent uniprocessor systems have one.
 775
 776           If you have a single-CPU system with an IO-APIC, you can say Y here
 777           to use it. If you say Y here even though your machine doesn't have
 778           an IO-APIC, then the kernel will still run with no slowdown at all.
 779
 780 config X86_LOCAL_APIC
 781         def_bool y
 782         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 783
 784 config X86_IO_APIC
 785         def_bool y
 786         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 787
 788 config X86_VISWS_APIC
 789         def_bool y
 790         depends on X86_32 && X86_VISWS
 791
 792 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 793         bool "Reroute for broken boot IRQs"
 794         default n
 795         depends on X86_IO_APIC
 796         ---help---
 797           This option enables a workaround that fixes a source of
 798           spurious interrupts. This is recommended when threaded
 799           interrupt handling is used on systems where the generation of
 800           superfluous "boot interrupts" cannot be disabled.
 801
 802           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 803           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 804           kernel does during interrupt handling). On chipsets where this
 805           boot IRQ generation cannot be disabled, this workaround keeps
 806           the original IRQ line masked so that only the equivalent "boot
 807           IRQ" is delivered to the CPUs. The workaround also tells the
 808           kernel to set up the IRQ handler on the boot IRQ line. In this
 809           way only one interrupt is delivered to the kernel. Otherwise
 810           the spurious second interrupt may cause the kernel to bring
 811           down (vital) interrupt lines.
 812
 813           Only affects "broken" chipsets. Interrupt sharing may be
 814           increased on these systems.
 815
 816 config X86_MCE
 817         bool "Machine Check / overheating reporting"
 818         ---help---
 819           Machine Check support allows the processor to notify the
 820           kernel if it detects a problem (e.g. overheating, data corruption).
 821           The action the kernel takes depends on the severity of the problem,
 822           ranging from warning messages to halting the machine.
 823
 824 config X86_MCE_INTEL
 825         def_bool y
 826         prompt "Intel MCE features"
 827         depends on X86_MCE && X86_LOCAL_APIC
 828         ---help---
 829            Additional support for intel specific MCE features such as
 830            the thermal monitor.
 831
 832 config X86_MCE_AMD
 833         def_bool y
 834         prompt "AMD MCE features"
 835         depends on X86_MCE && X86_LOCAL_APIC
 836         ---help---
 837            Additional support for AMD specific MCE features such as
 838            the DRAM Error Threshold.
 839
 840 config X86_ANCIENT_MCE
 841         def_bool n
 842         depends on X86_32 && X86_MCE
 843         prompt "Support for old Pentium 5 / WinChip machine checks"
 844         ---help---
 845           Include support for machine check handling on old Pentium 5 or WinChip
 846           systems. These typically need to be enabled explicitely on the command
 847           line.
 848
 849 config X86_MCE_THRESHOLD
 850         depends on X86_MCE_AMD || X86_MCE_INTEL
 851         bool
 852         default y
 853
 854 config X86_MCE_INJECT
 855         depends on X86_MCE
 856         tristate "Machine check injector support"
 857         ---help---
 858           Provide support for injecting machine checks for testing purposes.
 859           If you don't know what a machine check is and you don't do kernel
 860           QA it is safe to say n.
 861
 862 config X86_THERMAL_VECTOR
 863         def_bool y
 864         depends on X86_MCE_INTEL
 865
 866 config VM86
 867         bool "Enable VM86 support" if EMBEDDED
 868         default y
 869         depends on X86_32
 870         ---help---
 871           This option is required by programs like DOSEMU to run 16-bit legacy
 872           code on X86 processors. It also may be needed by software like
 873           XFree86 to initialize some video cards via BIOS. Disabling this
 874           option saves about 6k.
 875
 876 config TOSHIBA
 877         tristate "Toshiba Laptop support"
 878         depends on X86_32
 879         ---help---
 880           This adds a driver to safely access the System Management Mode of
 881           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 882           not work on models with a Phoenix BIOS. The System Management Mode
 883           is used to set the BIOS and power saving options on Toshiba portables.
 884
 885           For information on utilities to make use of this driver see the
 886           Toshiba Linux utilities web site at:
 887           <http://www.buzzard.org.uk/toshiba/>.
 888
 889           Say Y if you intend to run this kernel on a Toshiba portable.
 890           Say N otherwise.
 891
 892 config I8K
 893         tristate "Dell laptop support"
 894         ---help---
 895           This adds a driver to safely access the System Management Mode
 896           of the CPU on the Dell Inspiron 8000. The System Management Mode
 897           is used to read cpu temperature and cooling fan status and to
 898           control the fans on the I8K portables.
 899
 900           This driver has been tested only on the Inspiron 8000 but it may
 901           also work with other Dell laptops. You can force loading on other
 902           models by passing the parameter `force=1' to the module. Use at
 903           your own risk.
 904
 905           For information on utilities to make use of this driver see the
 906           I8K Linux utilities web site at:
 907           <http://people.debian.org/~dz/i8k/>
 908
 909           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 910           Say N otherwise.
 911
 912 config X86_REBOOTFIXUPS
 913         bool "Enable X86 board specific fixups for reboot"
 914         depends on X86_32
 915         ---help---
 916           This enables chipset and/or board specific fixups to be done
 917           in order to get reboot to work correctly. This is only needed on
 918           some combinations of hardware and BIOS. The symptom, for which
 919           this config is intended, is when reboot ends with a stalled/hung
 920           system.
 921
 922           Currently, the only fixup is for the Geode machines using
 923           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 924
 925           Say Y if you want to enable the fixup. Currently, it's safe to
 926           enable this option even if you don't need it.
 927           Say N otherwise.
 928
 929 config MICROCODE
 930         tristate "/dev/cpu/microcode - microcode support"
 931         select FW_LOADER
 932         ---help---
 933           If you say Y here, you will be able to update the microcode on
 934           certain Intel and AMD processors. The Intel support is for the
 935           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 936           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 937           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 938           You will obviously need the actual microcode binary data itself
 939           which is not shipped with the Linux kernel.
 940
 941           This option selects the general module only, you need to select
 942           at least one vendor specific module as well.
 943
 944           To compile this driver as a module, choose M here: the
 945           module will be called microcode.
 946
 947 config MICROCODE_INTEL
 948         bool "Intel microcode patch loading support"
 949         depends on MICROCODE
 950         default MICROCODE
 951         select FW_LOADER
 952         ---help---
 953           This options enables microcode patch loading support for Intel
 954           processors.
 955
 956           For latest news and information on obtaining all the required
 957           Intel ingredients for this driver, check:
 958           <http://www.urbanmyth.org/microcode/>.
 959
 960 config MICROCODE_AMD
 961         bool "AMD microcode patch loading support"
 962         depends on MICROCODE
 963         select FW_LOADER
 964         ---help---
 965           If you select this option, microcode patch loading support for AMD
 966           processors will be enabled.
 967
 968 config MICROCODE_OLD_INTERFACE
 969         def_bool y
 970         depends on MICROCODE
 971
 972 config X86_MSR
 973         tristate "/dev/cpu/*/msr - Model-specific register support"
 974         ---help---
 975           This device gives privileged processes access to the x86
 976           Model-Specific Registers (MSRs).  It is a character device with
 977           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
 978           MSR accesses are directed to a specific CPU on multi-processor
 979           systems.
 980
 981 config X86_CPUID
 982         tristate "/dev/cpu/*/cpuid - CPU information support"
 983         ---help---
 984           This device gives processes access to the x86 CPUID instruction to
 985           be executed on a specific processor.  It is a character device
 986           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
 987           /dev/cpu/31/cpuid.
 988
 989 config X86_CPU_DEBUG
 990         tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
 991         ---help---
 992           If you select this option, this will provide various x86 CPUs
 993           information through debugfs.
 994
 995 choice
 996         prompt "High Memory Support"
 997         default HIGHMEM4G if !X86_NUMAQ
 998         default HIGHMEM64G if X86_NUMAQ
 999         depends on X86_32
1000
1001 config NOHIGHMEM
1002         bool "off"
1003         depends on !X86_NUMAQ
1004         ---help---
1005           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1006           However, the address space of 32-bit x86 processors is only 4
1007           Gigabytes large. That means that, if you have a large amount of
1008           physical memory, not all of it can be "permanently mapped" by the
1009           kernel. The physical memory that's not permanently mapped is called
1010           "high memory".
1011
1012           If you are compiling a kernel which will never run on a machine with
1013           more than 1 Gigabyte total physical RAM, answer "off" here (default
1014           choice and suitable for most users). This will result in a "3GB/1GB"
1015           split: 3GB are mapped so that each process sees a 3GB virtual memory
1016           space and the remaining part of the 4GB virtual memory space is used
1017           by the kernel to permanently map as much physical memory as
1018           possible.
1019
1020           If the machine has between 1 and 4 Gigabytes physical RAM, then
1021           answer "4GB" here.
1022
1023           If more than 4 Gigabytes is used then answer "64GB" here. This
1024           selection turns Intel PAE (Physical Address Extension) mode on.
1025           PAE implements 3-level paging on IA32 processors. PAE is fully
1026           supported by Linux, PAE mode is implemented on all recent Intel
1027           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1028           then the kernel will not boot on CPUs that don't support PAE!
1029
1030           The actual amount of total physical memory will either be
1031           auto detected or can be forced by using a kernel command line option
1032           such as "mem=256M". (Try "man bootparam" or see the documentation of
1033           your boot loader (lilo or loadlin) about how to pass options to the
1034           kernel at boot time.)
1035
1036           If unsure, say "off".
1037
1038 config HIGHMEM4G
1039         bool "4GB"
1040         depends on !X86_NUMAQ
1041         ---help---
1042           Select this if you have a 32-bit processor and between 1 and 4
1043           gigabytes of physical RAM.
1044
1045 config HIGHMEM64G
1046         bool "64GB"
1047         depends on !M386 && !M486
1048         select X86_PAE
1049         ---help---
1050           Select this if you have a 32-bit processor and more than 4
1051           gigabytes of physical RAM.
1052
1053 endchoice
1054
1055 choice
1056         depends on EXPERIMENTAL
1057         prompt "Memory split" if EMBEDDED
1058         default VMSPLIT_3G
1059         depends on X86_32
1060         ---help---
1061           Select the desired split between kernel and user memory.
1062
1063           If the address range available to the kernel is less than the
1064           physical memory installed, the remaining memory will be available
1065           as "high memory". Accessing high memory is a little more costly
1066           than low memory, as it needs to be mapped into the kernel first.
1067           Note that increasing the kernel address space limits the range
1068           available to user programs, making the address space there
1069           tighter.  Selecting anything other than the default 3G/1G split
1070           will also likely make your kernel incompatible with binary-only
1071           kernel modules.
1072
1073           If you are not absolutely sure what you are doing, leave this
1074           option alone!
1075
1076         config VMSPLIT_3G
1077                 bool "3G/1G user/kernel split"
1078         config VMSPLIT_3G_OPT
1079                 depends on !X86_PAE
1080                 bool "3G/1G user/kernel split (for full 1G low memory)"
1081         config VMSPLIT_2G
1082                 bool "2G/2G user/kernel split"
1083         config VMSPLIT_2G_OPT
1084                 depends on !X86_PAE
1085                 bool "2G/2G user/kernel split (for full 2G low memory)"
1086         config VMSPLIT_1G
1087                 bool "1G/3G user/kernel split"
1088 endchoice
1089
1090 config PAGE_OFFSET
1091         hex
1092         default 0xB0000000 if VMSPLIT_3G_OPT
1093         default 0x80000000 if VMSPLIT_2G
1094         default 0x78000000 if VMSPLIT_2G_OPT
1095         default 0x40000000 if VMSPLIT_1G
1096         default 0xC0000000
1097         depends on X86_32
1098
1099 config HIGHMEM
1100         def_bool y
1101         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1102
1103 config X86_PAE
1104         bool "PAE (Physical Address Extension) Support"
1105         depends on X86_32 && !HIGHMEM4G
1106         ---help---
1107           PAE is required for NX support, and furthermore enables
1108           larger swapspace support for non-overcommit purposes. It
1109           has the cost of more pagetable lookup overhead, and also
1110           consumes more pagetable space per process.
1111
1112 config ARCH_PHYS_ADDR_T_64BIT
1113         def_bool X86_64 || X86_PAE
1114
1115 config DIRECT_GBPAGES
1116         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1117         default y
1118         depends on X86_64
1119         ---help---
1120           Allow the kernel linear mapping to use 1GB pages on CPUs that
1121           support it. This can improve the kernel's performance a tiny bit by
1122           reducing TLB pressure. If in doubt, say "Y".
1123
1124 # Common NUMA Features
1125 config NUMA
1126         bool "Numa Memory Allocation and Scheduler Support"
1127         depends on SMP
1128         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1129         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1130         ---help---
1131           Enable NUMA (Non Uniform Memory Access) support.
1132
1133           The kernel will try to allocate memory used by a CPU on the
1134           local memory controller of the CPU and add some more
1135           NUMA awareness to the kernel.
1136
1137           For 64-bit this is recommended if the system is Intel Core i7
1138           (or later), AMD Opteron, or EM64T NUMA.
1139
1140           For 32-bit this is only needed on (rare) 32-bit-only platforms
1141           that support NUMA topologies, such as NUMAQ / Summit, or if you
1142           boot a 32-bit kernel on a 64-bit NUMA platform.
1143
1144           Otherwise, you should say N.
1145
1146 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1147         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1148
1149 config K8_NUMA
1150         def_bool y
1151         prompt "Old style AMD Opteron NUMA detection"
1152         depends on X86_64 && NUMA && PCI
1153         ---help---
1154           Enable K8 NUMA node topology detection.  You should say Y here if
1155           you have a multi processor AMD K8 system. This uses an old
1156           method to read the NUMA configuration directly from the builtin
1157           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1158           instead, which also takes priority if both are compiled in.
1159
1160 config X86_64_ACPI_NUMA
1161         def_bool y
1162         prompt "ACPI NUMA detection"
1163         depends on X86_64 && NUMA && ACPI && PCI
1164         select ACPI_NUMA
1165         ---help---
1166           Enable ACPI SRAT based node topology detection.
1167
1168 # Some NUMA nodes have memory ranges that span
1169 # other nodes.  Even though a pfn is valid and
1170 # between a node's start and end pfns, it may not
1171 # reside on that node.  See memmap_init_zone()
1172 # for details.
1173 config NODES_SPAN_OTHER_NODES
1174         def_bool y
1175         depends on X86_64_ACPI_NUMA
1176
1177 config NUMA_EMU
1178         bool "NUMA emulation"
1179         depends on X86_64 && NUMA
1180         ---help---
1181           Enable NUMA emulation. A flat machine will be split
1182           into virtual nodes when booted with "numa=fake=N", where N is the
1183           number of nodes. This is only useful for debugging.
1184
1185 config NODES_SHIFT
1186         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1187         range 1 9
1188         default "9" if MAXSMP
1189         default "6" if X86_64
1190         default "4" if X86_NUMAQ
1191         default "3"
1192         depends on NEED_MULTIPLE_NODES
1193         ---help---
1194           Specify the maximum number of NUMA Nodes available on the target
1195           system.  Increases memory reserved to accommodate various tables.
1196
1197 config HAVE_ARCH_BOOTMEM
1198         def_bool y
1199         depends on X86_32 && NUMA
1200
1201 config ARCH_HAVE_MEMORY_PRESENT
1202         def_bool y
1203         depends on X86_32 && DISCONTIGMEM
1204
1205 config NEED_NODE_MEMMAP_SIZE
1206         def_bool y
1207         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1208
1209 config HAVE_ARCH_ALLOC_REMAP
1210         def_bool y
1211         depends on X86_32 && NUMA
1212
1213 config ARCH_FLATMEM_ENABLE
1214         def_bool y
1215         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1216
1217 config ARCH_DISCONTIGMEM_ENABLE
1218         def_bool y
1219         depends on NUMA && X86_32
1220
1221 config ARCH_DISCONTIGMEM_DEFAULT
1222         def_bool y
1223         depends on NUMA && X86_32
1224
1225 config ARCH_PROC_KCORE_TEXT
1226         def_bool y
1227         depends on X86_64 && PROC_KCORE
1228
1229 config ARCH_SPARSEMEM_DEFAULT
1230         def_bool y
1231         depends on X86_64
1232
1233 config ARCH_SPARSEMEM_ENABLE
1234         def_bool y
1235         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1236         select SPARSEMEM_STATIC if X86_32
1237         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1238
1239 config ARCH_SELECT_MEMORY_MODEL
1240         def_bool y
1241         depends on ARCH_SPARSEMEM_ENABLE
1242
1243 config ARCH_MEMORY_PROBE
1244         def_bool X86_64
1245         depends on MEMORY_HOTPLUG
1246
1247 source "mm/Kconfig"
1248
1249 config HIGHPTE
1250         bool "Allocate 3rd-level pagetables from highmem"
1251         depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1252         ---help---
1253           The VM uses one page table entry for each page of physical memory.
1254           For systems with a lot of RAM, this can be wasteful of precious
1255           low memory.  Setting this option will put user-space page table
1256           entries in high memory.
1257
1258 config X86_CHECK_BIOS_CORRUPTION
1259         bool "Check for low memory corruption"
1260         ---help---
1261           Periodically check for memory corruption in low memory, which
1262           is suspected to be caused by BIOS.  Even when enabled in the
1263           configuration, it is disabled at runtime.  Enable it by
1264           setting "memory_corruption_check=1" on the kernel command
1265           line.  By default it scans the low 64k of memory every 60
1266           seconds; see the memory_corruption_check_size and
1267           memory_corruption_check_period parameters in
1268           Documentation/kernel-parameters.txt to adjust this.
1269
1270           When enabled with the default parameters, this option has
1271           almost no overhead, as it reserves a relatively small amount
1272           of memory and scans it infrequently.  It both detects corruption
1273           and prevents it from affecting the running system.
1274
1275           It is, however, intended as a diagnostic tool; if repeatable
1276           BIOS-originated corruption always affects the same memory,
1277           you can use memmap= to prevent the kernel from using that
1278           memory.
1279
1280 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1281         bool "Set the default setting of memory_corruption_check"
1282         depends on X86_CHECK_BIOS_CORRUPTION
1283         default y
1284         ---help---
1285           Set whether the default state of memory_corruption_check is
1286           on or off.
1287
1288 config X86_RESERVE_LOW_64K
1289         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1290         default y
1291         ---help---
1292           Reserve the first 64K of physical RAM on BIOSes that are known
1293           to potentially corrupt that memory range. A numbers of BIOSes are
1294           known to utilize this area during suspend/resume, so it must not
1295           be used by the kernel.
1296
1297           Set this to N if you are absolutely sure that you trust the BIOS
1298           to get all its memory reservations and usages right.
1299
1300           If you have doubts about the BIOS (e.g. suspend/resume does not
1301           work or there's kernel crashes after certain hardware hotplug
1302           events) and it's not AMI or Phoenix, then you might want to enable
1303           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1304           corruption patterns.
1305
1306           Say Y if unsure.
1307
1308 config MATH_EMULATION
1309         bool
1310         prompt "Math emulation" if X86_32
1311         ---help---
1312           Linux can emulate a math coprocessor (used for floating point
1313           operations) if you don't have one. 486DX and Pentium processors have
1314           a math coprocessor built in, 486SX and 386 do not, unless you added
1315           a 487DX or 387, respectively. (The messages during boot time can
1316           give you some hints here ["man dmesg"].) Everyone needs either a
1317           coprocessor or this emulation.
1318
1319           If you don't have a math coprocessor, you need to say Y here; if you
1320           say Y here even though you have a coprocessor, the coprocessor will
1321           be used nevertheless. (This behavior can be changed with the kernel
1322           command line option "no387", which comes handy if your coprocessor
1323           is broken. Try "man bootparam" or see the documentation of your boot
1324           loader (lilo or loadlin) about how to pass options to the kernel at
1325           boot time.) This means that it is a good idea to say Y here if you
1326           intend to use this kernel on different machines.
1327
1328           More information about the internals of the Linux math coprocessor
1329           emulation can be found in <file:arch/x86/math-emu/README>.
1330
1331           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1332           kernel, it won't hurt.
1333
1334 config MTRR
1335         bool
1336         default y
1337         prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1338         ---help---
1339           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1340           the Memory Type Range Registers (MTRRs) may be used to control
1341           processor access to memory ranges. This is most useful if you have
1342           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1343           allows bus write transfers to be combined into a larger transfer
1344           before bursting over the PCI/AGP bus. This can increase performance
1345           of image write operations 2.5 times or more. Saying Y here creates a
1346           /proc/mtrr file which may be used to manipulate your processor's
1347           MTRRs. Typically the X server should use this.
1348
1349           This code has a reasonably generic interface so that similar
1350           control registers on other processors can be easily supported
1351           as well:
1352
1353           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1354           Registers (ARRs) which provide a similar functionality to MTRRs. For
1355           these, the ARRs are used to emulate the MTRRs.
1356           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1357           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1358           write-combining. All of these processors are supported by this code
1359           and it makes sense to say Y here if you have one of them.
1360
1361           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1362           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1363           can lead to all sorts of problems, so it's good to say Y here.
1364
1365           You can safely say Y even if your machine doesn't have MTRRs, you'll
1366           just add about 9 KB to your kernel.
1367
1368           See <file:Documentation/x86/mtrr.txt> for more information.
1369
1370 config MTRR_SANITIZER
1371         def_bool y
1372         prompt "MTRR cleanup support"
1373         depends on MTRR
1374         ---help---
1375           Convert MTRR layout from continuous to discrete, so X drivers can
1376           add writeback entries.
1377
1378           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1379           The largest mtrr entry size for a continuous block can be set with
1380           mtrr_chunk_size.
1381
1382           If unsure, say Y.
1383
1384 config MTRR_SANITIZER_ENABLE_DEFAULT
1385         int "MTRR cleanup enable value (0-1)"
1386         range 0 1
1387         default "0"
1388         depends on MTRR_SANITIZER
1389         ---help---
1390           Enable mtrr cleanup default value
1391
1392 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1393         int "MTRR cleanup spare reg num (0-7)"
1394         range 0 7
1395         default "1"
1396         depends on MTRR_SANITIZER
1397         ---help---
1398           mtrr cleanup spare entries default, it can be changed via
1399           mtrr_spare_reg_nr=N on the kernel command line.
1400
1401 config X86_PAT
1402         bool
1403         default y
1404         prompt "x86 PAT support" if EMBEDDED
1405         depends on MTRR
1406         ---help---
1407           Use PAT attributes to setup page level cache control.
1408
1409           PATs are the modern equivalents of MTRRs and are much more
1410           flexible than MTRRs.
1411
1412           Say N here if you see bootup problems (boot crash, boot hang,
1413           spontaneous reboots) or a non-working video driver.
1414
1415           If unsure, say Y.
1416
1417 config ARCH_USES_PG_UNCACHED
1418         def_bool y
1419         depends on X86_PAT
1420
1421 config EFI
1422         bool "EFI runtime service support"
1423         depends on ACPI
1424         ---help---
1425           This enables the kernel to use EFI runtime services that are
1426           available (such as the EFI variable services).
1427
1428           This option is only useful on systems that have EFI firmware.
1429           In addition, you should use the latest ELILO loader available
1430           at <http://elilo.sourceforge.net> in order to take advantage
1431           of EFI runtime services. However, even with this option, the
1432           resultant kernel should continue to boot on existing non-EFI
1433           platforms.
1434
1435 config SECCOMP
1436         def_bool y
1437         prompt "Enable seccomp to safely compute untrusted bytecode"
1438         ---help---
1439           This kernel feature is useful for number crunching applications
1440           that may need to compute untrusted bytecode during their
1441           execution. By using pipes or other transports made available to
1442           the process as file descriptors supporting the read/write
1443           syscalls, it's possible to isolate those applications in
1444           their own address space using seccomp. Once seccomp is
1445           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1446           and the task is only allowed to execute a few safe syscalls
1447           defined by each seccomp mode.
1448
1449           If unsure, say Y. Only embedded should say N here.
1450
1451 config CC_STACKPROTECTOR
1452         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1453         ---help---
1454           This option turns on the -fstack-protector GCC feature. This
1455           feature puts, at the beginning of functions, a canary value on
1456           the stack just before the return address, and validates
1457           the value just before actually returning.  Stack based buffer
1458           overflows (that need to overwrite this return address) now also
1459           overwrite the canary, which gets detected and the attack is then
1460           neutralized via a kernel panic.
1461
1462           This feature requires gcc version 4.2 or above, or a distribution
1463           gcc with the feature backported. Older versions are automatically
1464           detected and for those versions, this configuration option is
1465           ignored. (and a warning is printed during bootup)
1466
1467 source kernel/Kconfig.hz
1468
1469 config KEXEC
1470         bool "kexec system call"
1471         ---help---
1472           kexec is a system call that implements the ability to shutdown your
1473           current kernel, and to start another kernel.  It is like a reboot
1474           but it is independent of the system firmware.   And like a reboot
1475           you can start any kernel with it, not just Linux.
1476
1477           The name comes from the similarity to the exec system call.
1478
1479           It is an ongoing process to be certain the hardware in a machine
1480           is properly shutdown, so do not be surprised if this code does not
1481           initially work for you.  It may help to enable device hotplugging
1482           support.  As of this writing the exact hardware interface is
1483           strongly in flux, so no good recommendation can be made.
1484
1485 config CRASH_DUMP
1486         bool "kernel crash dumps"
1487         depends on X86_64 || (X86_32 && HIGHMEM)
1488         ---help---
1489           Generate crash dump after being started by kexec.
1490           This should be normally only set in special crash dump kernels
1491           which are loaded in the main kernel with kexec-tools into
1492           a specially reserved region and then later executed after
1493           a crash by kdump/kexec. The crash dump kernel must be compiled
1494           to a memory address not used by the main kernel or BIOS using
1495           PHYSICAL_START, or it must be built as a relocatable image
1496           (CONFIG_RELOCATABLE=y).
1497           For more details see Documentation/kdump/kdump.txt
1498
1499 config KEXEC_JUMP
1500         bool "kexec jump (EXPERIMENTAL)"
1501         depends on EXPERIMENTAL
1502         depends on KEXEC && HIBERNATION
1503         ---help---
1504           Jump between original kernel and kexeced kernel and invoke
1505           code in physical address mode via KEXEC
1506
1507 config PHYSICAL_START
1508         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1509         default "0x1000000"
1510         ---help---
1511           This gives the physical address where the kernel is loaded.
1512
1513           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1514           bzImage will decompress itself to above physical address and
1515           run from there. Otherwise, bzImage will run from the address where
1516           it has been loaded by the boot loader and will ignore above physical
1517           address.
1518
1519           In normal kdump cases one does not have to set/change this option
1520           as now bzImage can be compiled as a completely relocatable image
1521           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1522           address. This option is mainly useful for the folks who don't want
1523           to use a bzImage for capturing the crash dump and want to use a
1524           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1525           to be specifically compiled to run from a specific memory area
1526           (normally a reserved region) and this option comes handy.
1527
1528           So if you are using bzImage for capturing the crash dump,
1529           leave the value here unchanged to 0x1000000 and set
1530           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1531           for capturing the crash dump change this value to start of
1532           the reserved region.  In other words, it can be set based on
1533           the "X" value as specified in the "crashkernel=YM@XM"
1534           command line boot parameter passed to the panic-ed
1535           kernel. Please take a look at Documentation/kdump/kdump.txt
1536           for more details about crash dumps.
1537
1538           Usage of bzImage for capturing the crash dump is recommended as
1539           one does not have to build two kernels. Same kernel can be used
1540           as production kernel and capture kernel. Above option should have
1541           gone away after relocatable bzImage support is introduced. But it
1542           is present because there are users out there who continue to use
1543           vmlinux for dump capture. This option should go away down the
1544           line.
1545
1546           Don't change this unless you know what you are doing.
1547
1548 config RELOCATABLE
1549         bool "Build a relocatable kernel"
1550         default y
1551         ---help---
1552           This builds a kernel image that retains relocation information
1553           so it can be loaded someplace besides the default 1MB.
1554           The relocations tend to make the kernel binary about 10% larger,
1555           but are discarded at runtime.
1556
1557           One use is for the kexec on panic case where the recovery kernel
1558           must live at a different physical address than the primary
1559           kernel.
1560
1561           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1562           it has been loaded at and the compile time physical address
1563           (CONFIG_PHYSICAL_START) is ignored.
1564
1565 # Relocation on x86-32 needs some additional build support
1566 config X86_NEED_RELOCS
1567         def_bool y
1568         depends on X86_32 && RELOCATABLE
1569
1570 config PHYSICAL_ALIGN
1571         hex
1572         prompt "Alignment value to which kernel should be aligned" if X86_32
1573         default "0x1000000"
1574         range 0x2000 0x1000000
1575         ---help---
1576           This value puts the alignment restrictions on physical address
1577           where kernel is loaded and run from. Kernel is compiled for an
1578           address which meets above alignment restriction.
1579
1580           If bootloader loads the kernel at a non-aligned address and
1581           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1582           address aligned to above value and run from there.
1583
1584           If bootloader loads the kernel at a non-aligned address and
1585           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1586           load address and decompress itself to the address it has been
1587           compiled for and run from there. The address for which kernel is
1588           compiled already meets above alignment restrictions. Hence the
1589           end result is that kernel runs from a physical address meeting
1590           above alignment restrictions.
1591
1592           Don't change this unless you know what you are doing.
1593
1594 config HOTPLUG_CPU
1595         bool "Support for hot-pluggable CPUs"
1596         depends on SMP && HOTPLUG
1597         ---help---
1598           Say Y here to allow turning CPUs off and on. CPUs can be
1599           controlled through /sys/devices/system/cpu.
1600           ( Note: power management support will enable this option
1601             automatically on SMP systems. )
1602           Say N if you want to disable CPU hotplug.
1603
1604 config COMPAT_VDSO
1605         def_bool y
1606         prompt "Compat VDSO support"
1607         depends on X86_32 || IA32_EMULATION
1608         ---help---
1609           Map the 32-bit VDSO to the predictable old-style address too.
1610
1611           Say N here if you are running a sufficiently recent glibc
1612           version (2.3.3 or later), to remove the high-mapped
1613           VDSO mapping and to exclusively use the randomized VDSO.
1614
1615           If unsure, say Y.
1616
1617 config CMDLINE_BOOL
1618         bool "Built-in kernel command line"
1619         default n
1620         ---help---
1621           Allow for specifying boot arguments to the kernel at
1622           build time.  On some systems (e.g. embedded ones), it is
1623           necessary or convenient to provide some or all of the
1624           kernel boot arguments with the kernel itself (that is,
1625           to not rely on the boot loader to provide them.)
1626
1627           To compile command line arguments into the kernel,
1628           set this option to 'Y', then fill in the
1629           the boot arguments in CONFIG_CMDLINE.
1630
1631           Systems with fully functional boot loaders (i.e. non-embedded)
1632           should leave this option set to 'N'.
1633
1634 config CMDLINE
1635         string "Built-in kernel command string"
1636         depends on CMDLINE_BOOL
1637         default ""
1638         ---help---
1639           Enter arguments here that should be compiled into the kernel
1640           image and used at boot time.  If the boot loader provides a
1641           command line at boot time, it is appended to this string to
1642           form the full kernel command line, when the system boots.
1643
1644           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1645           change this behavior.
1646
1647           In most cases, the command line (whether built-in or provided
1648           by the boot loader) should specify the device for the root
1649           file system.
1650
1651 config CMDLINE_OVERRIDE
1652         bool "Built-in command line overrides boot loader arguments"
1653         default n
1654         depends on CMDLINE_BOOL
1655         ---help---
1656           Set this option to 'Y' to have the kernel ignore the boot loader
1657           command line, and use ONLY the built-in command line.
1658
1659           This is used to work around broken boot loaders.  This should
1660           be set to 'N' under normal conditions.
1661
1662 endmenu
1663
1664 config ARCH_ENABLE_MEMORY_HOTPLUG
1665         def_bool y
1666         depends on X86_64 || (X86_32 && HIGHMEM)
1667
1668 config ARCH_ENABLE_MEMORY_HOTREMOVE
1669         def_bool y
1670         depends on MEMORY_HOTPLUG
1671
1672 config HAVE_ARCH_EARLY_PFN_TO_NID
1673         def_bool X86_64
1674         depends on NUMA
1675
1676 menu "Power management and ACPI options"
1677
1678 config ARCH_HIBERNATION_HEADER
1679         def_bool y
1680         depends on X86_64 && HIBERNATION
1681
1682 source "kernel/power/Kconfig"
1683
1684 source "drivers/acpi/Kconfig"
1685
1686 source "drivers/sfi/Kconfig"
1687
1688 config X86_APM_BOOT
1689         bool
1690         default y
1691         depends on APM || APM_MODULE
1692
1693 menuconfig APM
1694         tristate "APM (Advanced Power Management) BIOS support"
1695         depends on X86_32 && PM_SLEEP
1696         ---help---
1697           APM is a BIOS specification for saving power using several different
1698           techniques. This is mostly useful for battery powered laptops with
1699           APM compliant BIOSes. If you say Y here, the system time will be
1700           reset after a RESUME operation, the /proc/apm device will provide
1701           battery status information, and user-space programs will receive
1702           notification of APM "events" (e.g. battery status change).
1703
1704           If you select "Y" here, you can disable actual use of the APM
1705           BIOS by passing the "apm=off" option to the kernel at boot time.
1706
1707           Note that the APM support is almost completely disabled for
1708           machines with more than one CPU.
1709
1710           In order to use APM, you will need supporting software. For location
1711           and more information, read <file:Documentation/power/pm.txt> and the
1712           Battery Powered Linux mini-HOWTO, available from
1713           <http://www.tldp.org/docs.html#howto>.
1714
1715           This driver does not spin down disk drives (see the hdparm(8)
1716           manpage ("man 8 hdparm") for that), and it doesn't turn off
1717           VESA-compliant "green" monitors.
1718
1719           This driver does not support the TI 4000M TravelMate and the ACER
1720           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1721           desktop machines also don't have compliant BIOSes, and this driver
1722           may cause those machines to panic during the boot phase.
1723
1724           Generally, if you don't have a battery in your machine, there isn't
1725           much point in using this driver and you should say N. If you get
1726           random kernel OOPSes or reboots that don't seem to be related to
1727           anything, try disabling/enabling this option (or disabling/enabling
1728           APM in your BIOS).
1729
1730           Some other things you should try when experiencing seemingly random,
1731           "weird" problems:
1732
1733           1) make sure that you have enough swap space and that it is
1734           enabled.
1735           2) pass the "no-hlt" option to the kernel
1736           3) switch on floating point emulation in the kernel and pass
1737           the "no387" option to the kernel
1738           4) pass the "floppy=nodma" option to the kernel
1739           5) pass the "mem=4M" option to the kernel (thereby disabling
1740           all but the first 4 MB of RAM)
1741           6) make sure that the CPU is not over clocked.
1742           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1743           8) disable the cache from your BIOS settings
1744           9) install a fan for the video card or exchange video RAM
1745           10) install a better fan for the CPU
1746           11) exchange RAM chips
1747           12) exchange the motherboard.
1748
1749           To compile this driver as a module, choose M here: the
1750           module will be called apm.
1751
1752 if APM
1753
1754 config APM_IGNORE_USER_SUSPEND
1755         bool "Ignore USER SUSPEND"
1756         ---help---
1757           This option will ignore USER SUSPEND requests. On machines with a
1758           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1759           series notebooks, it is necessary to say Y because of a BIOS bug.
1760
1761 config APM_DO_ENABLE
1762         bool "Enable PM at boot time"
1763         ---help---
1764           Enable APM features at boot time. From page 36 of the APM BIOS
1765           specification: "When disabled, the APM BIOS does not automatically
1766           power manage devices, enter the Standby State, enter the Suspend
1767           State, or take power saving steps in response to CPU Idle calls."
1768           This driver will make CPU Idle calls when Linux is idle (unless this
1769           feature is turned off -- see "Do CPU IDLE calls", below). This
1770           should always save battery power, but more complicated APM features
1771           will be dependent on your BIOS implementation. You may need to turn
1772           this option off if your computer hangs at boot time when using APM
1773           support, or if it beeps continuously instead of suspending. Turn
1774           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1775           T400CDT. This is off by default since most machines do fine without
1776           this feature.
1777
1778 config APM_CPU_IDLE
1779         bool "Make CPU Idle calls when idle"
1780         ---help---
1781           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1782           On some machines, this can activate improved power savings, such as
1783           a slowed CPU clock rate, when the machine is idle. These idle calls
1784           are made after the idle loop has run for some length of time (e.g.,
1785           333 mS). On some machines, this will cause a hang at boot time or
1786           whenever the CPU becomes idle. (On machines with more than one CPU,
1787           this option does nothing.)
1788
1789 config APM_DISPLAY_BLANK
1790         bool "Enable console blanking using APM"
1791         ---help---
1792           Enable console blanking using the APM. Some laptops can use this to
1793           turn off the LCD backlight when the screen blanker of the Linux
1794           virtual console blanks the screen. Note that this is only used by
1795           the virtual console screen blanker, and won't turn off the backlight
1796           when using the X Window system. This also doesn't have anything to
1797           do with your VESA-compliant power-saving monitor. Further, this
1798           option doesn't work for all laptops -- it might not turn off your
1799           backlight at all, or it might print a lot of errors to the console,
1800           especially if you are using gpm.
1801
1802 config APM_ALLOW_INTS
1803         bool "Allow interrupts during APM BIOS calls"
1804         ---help---
1805           Normally we disable external interrupts while we are making calls to
1806           the APM BIOS as a measure to lessen the effects of a badly behaving
1807           BIOS implementation.  The BIOS should reenable interrupts if it
1808           needs to.  Unfortunately, some BIOSes do not -- especially those in
1809           many of the newer IBM Thinkpads.  If you experience hangs when you
1810           suspend, try setting this to Y.  Otherwise, say N.
1811
1812 endif # APM
1813
1814 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1815
1816 source "drivers/cpuidle/Kconfig"
1817
1818 source "drivers/idle/Kconfig"
1819
1820 endmenu
1821
1822
1823 menu "Bus options (PCI etc.)"
1824
1825 config PCI
1826         bool "PCI support"
1827         default y
1828         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1829         ---help---
1830           Find out whether you have a PCI motherboard. PCI is the name of a
1831           bus system, i.e. the way the CPU talks to the other stuff inside
1832           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1833           VESA. If you have PCI, say Y, otherwise N.
1834
1835 choice
1836         prompt "PCI access mode"
1837         depends on X86_32 && PCI
1838         default PCI_GOANY
1839         ---help---
1840           On PCI systems, the BIOS can be used to detect the PCI devices and
1841           determine their configuration. However, some old PCI motherboards
1842           have BIOS bugs and may crash if this is done. Also, some embedded
1843           PCI-based systems don't have any BIOS at all. Linux can also try to
1844           detect the PCI hardware directly without using the BIOS.
1845
1846           With this option, you can specify how Linux should detect the
1847           PCI devices. If you choose "BIOS", the BIOS will be used,
1848           if you choose "Direct", the BIOS won't be used, and if you
1849           choose "MMConfig", then PCI Express MMCONFIG will be used.
1850           If you choose "Any", the kernel will try MMCONFIG, then the
1851           direct access method and falls back to the BIOS if that doesn't
1852           work. If unsure, go with the default, which is "Any".
1853
1854 config PCI_GOBIOS
1855         bool "BIOS"
1856
1857 config PCI_GOMMCONFIG
1858         bool "MMConfig"
1859
1860 config PCI_GODIRECT
1861         bool "Direct"
1862
1863 config PCI_GOOLPC
1864         bool "OLPC"
1865         depends on OLPC
1866
1867 config PCI_GOANY
1868         bool "Any"
1869
1870 endchoice
1871
1872 config PCI_BIOS
1873         def_bool y
1874         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1875
1876 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1877 config PCI_DIRECT
1878         def_bool y
1879         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1880
1881 config PCI_MMCONFIG
1882         def_bool y
1883         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1884
1885 config PCI_OLPC
1886         def_bool y
1887         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1888
1889 config PCI_DOMAINS
1890         def_bool y
1891         depends on PCI
1892
1893 config PCI_MMCONFIG
1894         bool "Support mmconfig PCI config space access"
1895         depends on X86_64 && PCI && ACPI
1896
1897 config DMAR
1898         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1899         depends on PCI_MSI && ACPI && EXPERIMENTAL
1900         help
1901           DMA remapping (DMAR) devices support enables independent address
1902           translations for Direct Memory Access (DMA) from devices.
1903           These DMA remapping devices are reported via ACPI tables
1904           and include PCI device scope covered by these DMA
1905           remapping devices.
1906
1907 config DMAR_DEFAULT_ON
1908         def_bool y
1909         prompt "Enable DMA Remapping Devices by default"
1910         depends on DMAR
1911         help
1912           Selecting this option will enable a DMAR device at boot time if
1913           one is found. If this option is not selected, DMAR support can
1914           be enabled by passing intel_iommu=on to the kernel. It is
1915           recommended you say N here while the DMAR code remains
1916           experimental.
1917
1918 config DMAR_BROKEN_GFX_WA
1919         def_bool n
1920         prompt "Workaround broken graphics drivers (going away soon)"
1921         depends on DMAR && BROKEN
1922         ---help---
1923           Current Graphics drivers tend to use physical address
1924           for DMA and avoid using DMA APIs. Setting this config
1925           option permits the IOMMU driver to set a unity map for
1926           all the OS-visible memory. Hence the driver can continue
1927           to use physical addresses for DMA, at least until this
1928           option is removed in the 2.6.32 kernel.
1929
1930 config DMAR_FLOPPY_WA
1931         def_bool y
1932         depends on DMAR
1933         ---help---
1934           Floppy disk drivers are known to bypass DMA API calls
1935           thereby failing to work when IOMMU is enabled. This
1936           workaround will setup a 1:1 mapping for the first
1937           16MiB to make floppy (an ISA device) work.
1938
1939 config INTR_REMAP
1940         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1941         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1942         ---help---
1943           Supports Interrupt remapping for IO-APIC and MSI devices.
1944           To use x2apic mode in the CPU's which support x2APIC enhancements or
1945           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1946
1947 source "drivers/pci/pcie/Kconfig"
1948
1949 source "drivers/pci/Kconfig"
1950
1951 # x86_64 have no ISA slots, but do have ISA-style DMA.
1952 config ISA_DMA_API
1953         def_bool y
1954
1955 if X86_32
1956
1957 config ISA
1958         bool "ISA support"
1959         ---help---
1960           Find out whether you have ISA slots on your motherboard.  ISA is the
1961           name of a bus system, i.e. the way the CPU talks to the other stuff
1962           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1963           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1964           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1965
1966 config EISA
1967         bool "EISA support"
1968         depends on ISA
1969         ---help---
1970           The Extended Industry Standard Architecture (EISA) bus was
1971           developed as an open alternative to the IBM MicroChannel bus.
1972
1973           The EISA bus provided some of the features of the IBM MicroChannel
1974           bus while maintaining backward compatibility with cards made for
1975           the older ISA bus.  The EISA bus saw limited use between 1988 and
1976           1995 when it was made obsolete by the PCI bus.
1977
1978           Say Y here if you are building a kernel for an EISA-based machine.
1979
1980           Otherwise, say N.
1981
1982 source "drivers/eisa/Kconfig"
1983
1984 config MCA
1985         bool "MCA support"
1986         ---help---
1987           MicroChannel Architecture is found in some IBM PS/2 machines and
1988           laptops.  It is a bus system similar to PCI or ISA. See
1989           <file:Documentation/mca.txt> (and especially the web page given
1990           there) before attempting to build an MCA bus kernel.
1991
1992 source "drivers/mca/Kconfig"
1993
1994 config SCx200
1995         tristate "NatSemi SCx200 support"
1996         ---help---
1997           This provides basic support for National Semiconductor's
1998           (now AMD's) Geode processors.  The driver probes for the
1999           PCI-IDs of several on-chip devices, so its a good dependency
2000           for other scx200_* drivers.
2001
2002           If compiled as a module, the driver is named scx200.
2003
2004 config SCx200HR_TIMER
2005         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2006         depends on SCx200 && GENERIC_TIME
2007         default y
2008         ---help---
2009           This driver provides a clocksource built upon the on-chip
2010           27MHz high-resolution timer.  Its also a workaround for
2011           NSC Geode SC-1100's buggy TSC, which loses time when the
2012           processor goes idle (as is done by the scheduler).  The
2013           other workaround is idle=poll boot option.
2014
2015 config GEODE_MFGPT_TIMER
2016         def_bool y
2017         prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2018         depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2019         ---help---
2020           This driver provides a clock event source based on the MFGPT
2021           timer(s) in the CS5535 and CS5536 companion chip for the geode.
2022           MFGPTs have a better resolution and max interval than the
2023           generic PIT, and are suitable for use as high-res timers.
2024
2025 config OLPC
2026         bool "One Laptop Per Child support"
2027         default n
2028         ---help---
2029           Add support for detecting the unique features of the OLPC
2030           XO hardware.
2031
2032 endif # X86_32
2033
2034 config K8_NB
2035         def_bool y
2036         depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2037
2038 source "drivers/pcmcia/Kconfig"
2039
2040 source "drivers/pci/hotplug/Kconfig"
2041
2042 endmenu
2043
2044
2045 menu "Executable file formats / Emulations"
2046
2047 source "fs/Kconfig.binfmt"
2048
2049 config IA32_EMULATION
2050         bool "IA32 Emulation"
2051         depends on X86_64
2052         select COMPAT_BINFMT_ELF
2053         ---help---
2054           Include code to run 32-bit programs under a 64-bit kernel. You should
2055           likely turn this on, unless you're 100% sure that you don't have any
2056           32-bit programs left.
2057
2058 config IA32_AOUT
2059         tristate "IA32 a.out support"
2060         depends on IA32_EMULATION
2061         ---help---
2062           Support old a.out binaries in the 32bit emulation.
2063
2064 config COMPAT
2065         def_bool y
2066         depends on IA32_EMULATION
2067
2068 config COMPAT_FOR_U64_ALIGNMENT
2069         def_bool COMPAT
2070         depends on X86_64
2071
2072 config SYSVIPC_COMPAT
2073         def_bool y
2074         depends on COMPAT && SYSVIPC
2075
2076 endmenu
2077
2078
2079 config HAVE_ATOMIC_IOMAP
2080         def_bool y
2081         depends on X86_32
2082
2083 source "net/Kconfig"
2084
2085 source "drivers/Kconfig"
2086
2087 source "drivers/firmware/Kconfig"
2088
2089 source "fs/Kconfig"
2090
2091 source "arch/x86/Kconfig.debug"
2092
2093 source "security/Kconfig"
2094
2095 source "crypto/Kconfig"
2096
2097 source "arch/x86/kvm/Kconfig"
2098
2099 source "lib/Kconfig"