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_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  38         select HAVE_FTRACE_SYSCALLS
  39         select HAVE_KVM
  40         select HAVE_ARCH_KGDB
  41         select HAVE_ARCH_TRACEHOOK
  42         select HAVE_GENERIC_DMA_COHERENT if X86_32
  43         select HAVE_EFFICIENT_UNALIGNED_ACCESS
  44         select USER_STACKTRACE_SUPPORT
  45         select HAVE_DMA_API_DEBUG
  46         select HAVE_KERNEL_GZIP
  47         select HAVE_KERNEL_BZIP2
  48         select HAVE_KERNEL_LZMA
  49
  50 config ARCH_DEFCONFIG
  51         string
  52         default "arch/x86/configs/i386_defconfig" if X86_32
  53         default "arch/x86/configs/x86_64_defconfig" if X86_64
  54
  55 config GENERIC_TIME
  56         def_bool y
  57
  58 config GENERIC_CMOS_UPDATE
  59         def_bool y
  60
  61 config CLOCKSOURCE_WATCHDOG
  62         def_bool y
  63
  64 config GENERIC_CLOCKEVENTS
  65         def_bool y
  66
  67 config GENERIC_CLOCKEVENTS_BROADCAST
  68         def_bool y
  69         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  70
  71 config LOCKDEP_SUPPORT
  72         def_bool y
  73
  74 config STACKTRACE_SUPPORT
  75         def_bool y
  76
  77 config HAVE_LATENCYTOP_SUPPORT
  78         def_bool y
  79
  80 config FAST_CMPXCHG_LOCAL
  81         bool
  82         default y
  83
  84 config MMU
  85         def_bool y
  86
  87 config ZONE_DMA
  88         def_bool y
  89
  90 config SBUS
  91         bool
  92
  93 config GENERIC_ISA_DMA
  94         def_bool y
  95
  96 config GENERIC_IOMAP
  97         def_bool y
  98
  99 config GENERIC_BUG
 100         def_bool y
 101         depends on BUG
 102         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 103
 104 config GENERIC_BUG_RELATIVE_POINTERS
 105         bool
 106
 107 config GENERIC_HWEIGHT
 108         def_bool y
 109
 110 config GENERIC_GPIO
 111         bool
 112
 113 config ARCH_MAY_HAVE_PC_FDC
 114         def_bool y
 115
 116 config RWSEM_GENERIC_SPINLOCK
 117         def_bool !X86_XADD
 118
 119 config RWSEM_XCHGADD_ALGORITHM
 120         def_bool X86_XADD
 121
 122 config ARCH_HAS_CPU_IDLE_WAIT
 123         def_bool y
 124
 125 config GENERIC_CALIBRATE_DELAY
 126         def_bool y
 127
 128 config GENERIC_TIME_VSYSCALL
 129         bool
 130         default X86_64
 131
 132 config ARCH_HAS_CPU_RELAX
 133         def_bool y
 134
 135 config ARCH_HAS_DEFAULT_IDLE
 136         def_bool y
 137
 138 config ARCH_HAS_CACHE_LINE_SIZE
 139         def_bool y
 140
 141 config HAVE_SETUP_PER_CPU_AREA
 142         def_bool y
 143
 144 config HAVE_DYNAMIC_PER_CPU_AREA
 145         def_bool y
 146
 147 config HAVE_CPUMASK_OF_CPU_MAP
 148         def_bool X86_64_SMP
 149
 150 config ARCH_HIBERNATION_POSSIBLE
 151         def_bool y
 152
 153 config ARCH_SUSPEND_POSSIBLE
 154         def_bool y
 155
 156 config ZONE_DMA32
 157         bool
 158         default X86_64
 159
 160 config ARCH_POPULATES_NODE_MAP
 161         def_bool y
 162
 163 config AUDIT_ARCH
 164         bool
 165         default X86_64
 166
 167 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 168         def_bool y
 169
 170 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 171         def_bool y
 172
 173 # Use the generic interrupt handling code in kernel/irq/:
 174 config GENERIC_HARDIRQS
 175         bool
 176         default y
 177
 178 config GENERIC_HARDIRQS_NO__DO_IRQ
 179        def_bool y
 180
 181 config GENERIC_IRQ_PROBE
 182         bool
 183         default y
 184
 185 config GENERIC_PENDING_IRQ
 186         bool
 187         depends on GENERIC_HARDIRQS && SMP
 188         default y
 189
 190 config USE_GENERIC_SMP_HELPERS
 191         def_bool y
 192         depends on SMP
 193
 194 config X86_32_SMP
 195         def_bool y
 196         depends on X86_32 && SMP
 197
 198 config X86_64_SMP
 199         def_bool y
 200         depends on X86_64 && SMP
 201
 202 config X86_HT
 203         bool
 204         depends on SMP
 205         default y
 206
 207 config X86_TRAMPOLINE
 208         bool
 209         depends on SMP || (64BIT && ACPI_SLEEP)
 210         default y
 211
 212 config X86_32_LAZY_GS
 213         def_bool y
 214         depends on X86_32 && !CC_STACKPROTECTOR
 215
 216 config KTIME_SCALAR
 217         def_bool X86_32
 218 source "init/Kconfig"
 219 source "kernel/Kconfig.freezer"
 220
 221 menu "Processor type and features"
 222
 223 source "kernel/time/Kconfig"
 224
 225 config SMP
 226         bool "Symmetric multi-processing support"
 227         ---help---
 228           This enables support for systems with more than one CPU. If you have
 229           a system with only one CPU, like most personal computers, say N. If
 230           you have a system with more than one CPU, say Y.
 231
 232           If you say N here, the kernel will run on single and multiprocessor
 233           machines, but will use only one CPU of a multiprocessor machine. If
 234           you say Y here, the kernel will run on many, but not all,
 235           singleprocessor machines. On a singleprocessor machine, the kernel
 236           will run faster if you say N here.
 237
 238           Note that if you say Y here and choose architecture "586" or
 239           "Pentium" under "Processor family", the kernel will not work on 486
 240           architectures. Similarly, multiprocessor kernels for the "PPro"
 241           architecture may not work on all Pentium based boards.
 242
 243           People using multiprocessor machines who say Y here should also say
 244           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 245           Management" code will be disabled if you say Y here.
 246
 247           See also <file:Documentation/i386/IO-APIC.txt>,
 248           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 249           <http://www.tldp.org/docs.html#howto>.
 250
 251           If you don't know what to do here, say N.
 252
 253 config X86_X2APIC
 254         bool "Support x2apic"
 255         depends on X86_LOCAL_APIC && X86_64
 256         select INTR_REMAP
 257         ---help---
 258           This enables x2apic support on CPUs that have this feature.
 259
 260           This allows 32-bit apic IDs (so it can support very large systems),
 261           and accesses the local apic via MSRs not via mmio.
 262
 263           ( On certain CPU models you may need to enable INTR_REMAP too,
 264             to get functional x2apic mode. )
 265
 266           If you don't know what to do here, say N.
 267
 268 config SPARSE_IRQ
 269         bool "Support sparse irq numbering"
 270         depends on PCI_MSI || HT_IRQ
 271         ---help---
 272           This enables support for sparse irqs. This is useful for distro
 273           kernels that want to define a high CONFIG_NR_CPUS value but still
 274           want to have low kernel memory footprint on smaller machines.
 275
 276           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 277             out the irq_desc[] array in a more NUMA-friendly way. )
 278
 279           If you don't know what to do here, say N.
 280
 281 config NUMA_MIGRATE_IRQ_DESC
 282         bool "Move irq desc when changing irq smp_affinity"
 283         depends on SPARSE_IRQ && NUMA
 284         default n
 285         ---help---
 286           This enables moving irq_desc to cpu/node that irq will use handled.
 287
 288           If you don't know what to do here, say N.
 289
 290 config X86_MPPARSE
 291         bool "Enable MPS table" if ACPI
 292         default y
 293         depends on X86_LOCAL_APIC
 294         ---help---
 295           For old smp systems that do not have proper acpi support. Newer systems
 296           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 297
 298 config X86_BIGSMP
 299         bool "Support for big SMP systems with more than 8 CPUs"
 300         depends on X86_32 && SMP
 301         ---help---
 302           This option is needed for the systems that have more than 8 CPUs
 303
 304 if X86_32
 305 config X86_EXTENDED_PLATFORM
 306         bool "Support for extended (non-PC) x86 platforms"
 307         default y
 308         ---help---
 309           If you disable this option then the kernel will only support
 310           standard PC platforms. (which covers the vast majority of
 311           systems out there.)
 312
 313           If you enable this option then you'll be able to select support
 314           for the following (non-PC) 32 bit x86 platforms:
 315                 AMD Elan
 316                 NUMAQ (IBM/Sequent)
 317                 RDC R-321x SoC
 318                 SGI 320/540 (Visual Workstation)
 319                 Summit/EXA (IBM x440)
 320                 Unisys ES7000 IA32 series
 321
 322           If you have one of these systems, or if you want to build a
 323           generic distribution kernel, say Y here - otherwise say N.
 324 endif
 325
 326 if X86_64
 327 config X86_EXTENDED_PLATFORM
 328         bool "Support for extended (non-PC) x86 platforms"
 329         default y
 330         ---help---
 331           If you disable this option then the kernel will only support
 332           standard PC platforms. (which covers the vast majority of
 333           systems out there.)
 334
 335           If you enable this option then you'll be able to select support
 336           for the following (non-PC) 64 bit x86 platforms:
 337                 ScaleMP vSMP
 338                 SGI Ultraviolet
 339
 340           If you have one of these systems, or if you want to build a
 341           generic distribution kernel, say Y here - otherwise say N.
 342 endif
 343 # This is an alphabetically sorted list of 64 bit extended platforms
 344 # Please maintain the alphabetic order if and when there are additions
 345
 346 config X86_VSMP
 347         bool "ScaleMP vSMP"
 348         select PARAVIRT
 349         depends on X86_64 && PCI
 350         depends on X86_EXTENDED_PLATFORM
 351         ---help---
 352           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 353           supposed to run on these EM64T-based machines.  Only choose this option
 354           if you have one of these machines.
 355
 356 config X86_UV
 357         bool "SGI Ultraviolet"
 358         depends on X86_64
 359         depends on X86_EXTENDED_PLATFORM
 360         select X86_X2APIC
 361         ---help---
 362           This option is needed in order to support SGI Ultraviolet systems.
 363           If you don't have one of these, you should say N here.
 364
 365 # Following is an alphabetically sorted list of 32 bit extended platforms
 366 # Please maintain the alphabetic order if and when there are additions
 367
 368 config X86_ELAN
 369         bool "AMD Elan"
 370         depends on X86_32
 371         depends on X86_EXTENDED_PLATFORM
 372         ---help---
 373           Select this for an AMD Elan processor.
 374
 375           Do not use this option for K6/Athlon/Opteron processors!
 376
 377           If unsure, choose "PC-compatible" instead.
 378
 379 config X86_RDC321X
 380         bool "RDC R-321x SoC"
 381         depends on X86_32
 382         depends on X86_EXTENDED_PLATFORM
 383         select M486
 384         select X86_REBOOTFIXUPS
 385         ---help---
 386           This option is needed for RDC R-321x system-on-chip, also known
 387           as R-8610-(G).
 388           If you don't have one of these chips, you should say N here.
 389
 390 config X86_32_NON_STANDARD
 391         bool "Support non-standard 32-bit SMP architectures"
 392         depends on X86_32 && SMP
 393         depends on X86_EXTENDED_PLATFORM
 394         ---help---
 395           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 396           subarchitectures.  It is intended for a generic binary kernel.
 397           if you select them all, kernel will probe it one by one. and will
 398           fallback to default.
 399
 400 # Alphabetically sorted list of Non standard 32 bit platforms
 401
 402 config X86_NUMAQ
 403         bool "NUMAQ (IBM/Sequent)"
 404         depends on X86_32_NON_STANDARD
 405         select NUMA
 406         select X86_MPPARSE
 407         ---help---
 408           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 409           NUMA multiquad box. This changes the way that processors are
 410           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 411           of Flat Logical.  You will need a new lynxer.elf file to flash your
 412           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 413
 414 config X86_VISWS
 415         bool "SGI 320/540 (Visual Workstation)"
 416         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 417         depends on X86_32_NON_STANDARD
 418         ---help---
 419           The SGI Visual Workstation series is an IA32-based workstation
 420           based on SGI systems chips with some legacy PC hardware attached.
 421
 422           Say Y here to create a kernel to run on the SGI 320 or 540.
 423
 424           A kernel compiled for the Visual Workstation will run on general
 425           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 426
 427 config X86_SUMMIT
 428         bool "Summit/EXA (IBM x440)"
 429         depends on X86_32_NON_STANDARD
 430         ---help---
 431           This option is needed for IBM systems that use the Summit/EXA chipset.
 432           In particular, it is needed for the x440.
 433
 434 config X86_ES7000
 435         bool "Unisys ES7000 IA32 series"
 436         depends on X86_32_NON_STANDARD && X86_BIGSMP
 437         ---help---
 438           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 439           supposed to run on an IA32-based Unisys ES7000 system.
 440
 441 config SCHED_OMIT_FRAME_POINTER
 442         def_bool y
 443         prompt "Single-depth WCHAN output"
 444         depends on X86
 445         ---help---
 446           Calculate simpler /proc/<PID>/wchan values. If this option
 447           is disabled then wchan values will recurse back to the
 448           caller function. This provides more accurate wchan values,
 449           at the expense of slightly more scheduling overhead.
 450
 451           If in doubt, say "Y".
 452
 453 menuconfig PARAVIRT_GUEST
 454         bool "Paravirtualized guest support"
 455         ---help---
 456           Say Y here to get to see options related to running Linux under
 457           various hypervisors.  This option alone does not add any kernel code.
 458
 459           If you say N, all options in this submenu will be skipped and disabled.
 460
 461 if PARAVIRT_GUEST
 462
 463 source "arch/x86/xen/Kconfig"
 464
 465 config VMI
 466         bool "VMI Guest support"
 467         select PARAVIRT
 468         depends on X86_32
 469         ---help---
 470           VMI provides a paravirtualized interface to the VMware ESX server
 471           (it could be used by other hypervisors in theory too, but is not
 472           at the moment), by linking the kernel to a GPL-ed ROM module
 473           provided by the hypervisor.
 474
 475 config KVM_CLOCK
 476         bool "KVM paravirtualized clock"
 477         select PARAVIRT
 478         select PARAVIRT_CLOCK
 479         ---help---
 480           Turning on this option will allow you to run a paravirtualized clock
 481           when running over the KVM hypervisor. Instead of relying on a PIT
 482           (or probably other) emulation by the underlying device model, the host
 483           provides the guest with timing infrastructure such as time of day, and
 484           system time
 485
 486 config KVM_GUEST
 487         bool "KVM Guest support"
 488         select PARAVIRT
 489         ---help---
 490           This option enables various optimizations for running under the KVM
 491           hypervisor.
 492
 493 source "arch/x86/lguest/Kconfig"
 494
 495 config PARAVIRT
 496         bool "Enable paravirtualization code"
 497         ---help---
 498           This changes the kernel so it can modify itself when it is run
 499           under a hypervisor, potentially improving performance significantly
 500           over full virtualization.  However, when run without a hypervisor
 501           the kernel is theoretically slower and slightly larger.
 502
 503 config PARAVIRT_CLOCK
 504         bool
 505         default n
 506
 507 endif
 508
 509 config PARAVIRT_DEBUG
 510         bool "paravirt-ops debugging"
 511         depends on PARAVIRT && DEBUG_KERNEL
 512         ---help---
 513           Enable to debug paravirt_ops internals.  Specifically, BUG if
 514           a paravirt_op is missing when it is called.
 515
 516 config MEMTEST
 517         bool "Memtest"
 518         ---help---
 519           This option adds a kernel parameter 'memtest', which allows memtest
 520           to be set.
 521                 memtest=0, mean disabled; -- default
 522                 memtest=1, mean do 1 test pattern;
 523                 ...
 524                 memtest=4, mean do 4 test patterns.
 525           If you are unsure how to answer this question, answer N.
 526
 527 config X86_SUMMIT_NUMA
 528         def_bool y
 529         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 530
 531 config X86_CYCLONE_TIMER
 532         def_bool y
 533         depends on X86_32_NON_STANDARD
 534
 535 source "arch/x86/Kconfig.cpu"
 536
 537 config HPET_TIMER
 538         def_bool X86_64
 539         prompt "HPET Timer Support" if X86_32
 540         ---help---
 541           Use the IA-PC HPET (High Precision Event Timer) to manage
 542           time in preference to the PIT and RTC, if a HPET is
 543           present.
 544           HPET is the next generation timer replacing legacy 8254s.
 545           The HPET provides a stable time base on SMP
 546           systems, unlike the TSC, but it is more expensive to access,
 547           as it is off-chip.  You can find the HPET spec at
 548           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 549
 550           You can safely choose Y here.  However, HPET will only be
 551           activated if the platform and the BIOS support this feature.
 552           Otherwise the 8254 will be used for timing services.
 553
 554           Choose N to continue using the legacy 8254 timer.
 555
 556 config HPET_EMULATE_RTC
 557         def_bool y
 558         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 559
 560 # Mark as embedded because too many people got it wrong.
 561 # The code disables itself when not needed.
 562 config DMI
 563         default y
 564         bool "Enable DMI scanning" if EMBEDDED
 565         ---help---
 566           Enabled scanning of DMI to identify machine quirks. Say Y
 567           here unless you have verified that your setup is not
 568           affected by entries in the DMI blacklist. Required by PNP
 569           BIOS code.
 570
 571 config GART_IOMMU
 572         bool "GART IOMMU support" if EMBEDDED
 573         default y
 574         select SWIOTLB
 575         select AGP
 576         depends on X86_64 && PCI
 577         ---help---
 578           Support for full DMA access of devices with 32bit memory access only
 579           on systems with more than 3GB. This is usually needed for USB,
 580           sound, many IDE/SATA chipsets and some other devices.
 581           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 582           based hardware IOMMU and a software bounce buffer based IOMMU used
 583           on Intel systems and as fallback.
 584           The code is only active when needed (enough memory and limited
 585           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 586           too.
 587
 588 config CALGARY_IOMMU
 589         bool "IBM Calgary IOMMU support"
 590         select SWIOTLB
 591         depends on X86_64 && PCI && EXPERIMENTAL
 592         ---help---
 593           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 594           systems. Needed to run systems with more than 3GB of memory
 595           properly with 32-bit PCI devices that do not support DAC
 596           (Double Address Cycle). Calgary also supports bus level
 597           isolation, where all DMAs pass through the IOMMU.  This
 598           prevents them from going anywhere except their intended
 599           destination. This catches hard-to-find kernel bugs and
 600           mis-behaving drivers and devices that do not use the DMA-API
 601           properly to set up their DMA buffers.  The IOMMU can be
 602           turned off at boot time with the iommu=off parameter.
 603           Normally the kernel will make the right choice by itself.
 604           If unsure, say Y.
 605
 606 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 607         def_bool y
 608         prompt "Should Calgary be enabled by default?"
 609         depends on CALGARY_IOMMU
 610         ---help---
 611           Should Calgary be enabled by default? if you choose 'y', Calgary
 612           will be used (if it exists). If you choose 'n', Calgary will not be
 613           used even if it exists. If you choose 'n' and would like to use
 614           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 615           If unsure, say Y.
 616
 617 config AMD_IOMMU
 618         bool "AMD IOMMU support"
 619         select SWIOTLB
 620         select PCI_MSI
 621         depends on X86_64 && PCI && ACPI
 622         ---help---
 623           With this option you can enable support for AMD IOMMU hardware in
 624           your system. An IOMMU is a hardware component which provides
 625           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 626           can isolate the the DMA memory of different devices and protect the
 627           system from misbehaving device drivers or hardware.
 628
 629           You can find out if your system has an AMD IOMMU if you look into
 630           your BIOS for an option to enable it or if you have an IVRS ACPI
 631           table.
 632
 633 config AMD_IOMMU_STATS
 634         bool "Export AMD IOMMU statistics to debugfs"
 635         depends on AMD_IOMMU
 636         select DEBUG_FS
 637         ---help---
 638           This option enables code in the AMD IOMMU driver to collect various
 639           statistics about whats happening in the driver and exports that
 640           information to userspace via debugfs.
 641           If unsure, say N.
 642
 643 # need this always selected by IOMMU for the VIA workaround
 644 config SWIOTLB
 645         def_bool y if X86_64
 646         ---help---
 647           Support for software bounce buffers used on x86-64 systems
 648           which don't have a hardware IOMMU (e.g. the current generation
 649           of Intel's x86-64 CPUs). Using this PCI devices which can only
 650           access 32-bits of memory can be used on systems with more than
 651           3 GB of memory. If unsure, say Y.
 652
 653 config IOMMU_HELPER
 654         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 655
 656 config IOMMU_API
 657         def_bool (AMD_IOMMU || DMAR)
 658
 659 config MAXSMP
 660         bool "Configure Maximum number of SMP Processors and NUMA Nodes"
 661         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 662         select CPUMASK_OFFSTACK
 663         default n
 664         ---help---
 665           Configure maximum number of CPUS and NUMA Nodes for this architecture.
 666           If unsure, say N.
 667
 668 config NR_CPUS
 669         int "Maximum number of CPUs" if SMP && !MAXSMP
 670         range 2 512 if SMP && !MAXSMP
 671         default "1" if !SMP
 672         default "4096" if MAXSMP
 673         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 674         default "8" if SMP
 675         ---help---
 676           This allows you to specify the maximum number of CPUs which this
 677           kernel will support.  The maximum supported value is 512 and the
 678           minimum value which makes sense is 2.
 679
 680           This is purely to save memory - each supported CPU adds
 681           approximately eight kilobytes to the kernel image.
 682
 683 config SCHED_SMT
 684         bool "SMT (Hyperthreading) scheduler support"
 685         depends on X86_HT
 686         ---help---
 687           SMT scheduler support improves the CPU scheduler's decision making
 688           when dealing with Intel Pentium 4 chips with HyperThreading at a
 689           cost of slightly increased overhead in some places. If unsure say
 690           N here.
 691
 692 config SCHED_MC
 693         def_bool y
 694         prompt "Multi-core scheduler support"
 695         depends on X86_HT
 696         ---help---
 697           Multi-core scheduler support improves the CPU scheduler's decision
 698           making when dealing with multi-core CPU chips at a cost of slightly
 699           increased overhead in some places. If unsure say N here.
 700
 701 source "kernel/Kconfig.preempt"
 702
 703 config X86_UP_APIC
 704         bool "Local APIC support on uniprocessors"
 705         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 706         ---help---
 707           A local APIC (Advanced Programmable Interrupt Controller) is an
 708           integrated interrupt controller in the CPU. If you have a single-CPU
 709           system which has a processor with a local APIC, you can say Y here to
 710           enable and use it. If you say Y here even though your machine doesn't
 711           have a local APIC, then the kernel will still run with no slowdown at
 712           all. The local APIC supports CPU-generated self-interrupts (timer,
 713           performance counters), and the NMI watchdog which detects hard
 714           lockups.
 715
 716 config X86_UP_IOAPIC
 717         bool "IO-APIC support on uniprocessors"
 718         depends on X86_UP_APIC
 719         ---help---
 720           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 721           SMP-capable replacement for PC-style interrupt controllers. Most
 722           SMP systems and many recent uniprocessor systems have one.
 723
 724           If you have a single-CPU system with an IO-APIC, you can say Y here
 725           to use it. If you say Y here even though your machine doesn't have
 726           an IO-APIC, then the kernel will still run with no slowdown at all.
 727
 728 config X86_LOCAL_APIC
 729         def_bool y
 730         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 731
 732 config X86_IO_APIC
 733         def_bool y
 734         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 735
 736 config X86_VISWS_APIC
 737         def_bool y
 738         depends on X86_32 && X86_VISWS
 739
 740 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 741         bool "Reroute for broken boot IRQs"
 742         default n
 743         depends on X86_IO_APIC
 744         ---help---
 745           This option enables a workaround that fixes a source of
 746           spurious interrupts. This is recommended when threaded
 747           interrupt handling is used on systems where the generation of
 748           superfluous "boot interrupts" cannot be disabled.
 749
 750           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 751           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 752           kernel does during interrupt handling). On chipsets where this
 753           boot IRQ generation cannot be disabled, this workaround keeps
 754           the original IRQ line masked so that only the equivalent "boot
 755           IRQ" is delivered to the CPUs. The workaround also tells the
 756           kernel to set up the IRQ handler on the boot IRQ line. In this
 757           way only one interrupt is delivered to the kernel. Otherwise
 758           the spurious second interrupt may cause the kernel to bring
 759           down (vital) interrupt lines.
 760
 761           Only affects "broken" chipsets. Interrupt sharing may be
 762           increased on these systems.
 763
 764 config X86_MCE
 765         bool "Machine Check Exception"
 766         ---help---
 767           Machine Check Exception support allows the processor to notify the
 768           kernel if it detects a problem (e.g. overheating, component failure).
 769           The action the kernel takes depends on the severity of the problem,
 770           ranging from a warning message on the console, to halting the machine.
 771           Your processor must be a Pentium or newer to support this - check the
 772           flags in /proc/cpuinfo for mce.  Note that some older Pentium systems
 773           have a design flaw which leads to false MCE events - hence MCE is
 774           disabled on all P5 processors, unless explicitly enabled with "mce"
 775           as a boot argument.  Similarly, if MCE is built in and creates a
 776           problem on some new non-standard machine, you can boot with "nomce"
 777           to disable it.  MCE support simply ignores non-MCE processors like
 778           the 386 and 486, so nearly everyone can say Y here.
 779
 780 config X86_MCE_INTEL
 781         def_bool y
 782         prompt "Intel MCE features"
 783         depends on X86_64 && X86_MCE && X86_LOCAL_APIC
 784         ---help---
 785            Additional support for intel specific MCE features such as
 786            the thermal monitor.
 787
 788 config X86_MCE_AMD
 789         def_bool y
 790         prompt "AMD MCE features"
 791         depends on X86_64 && X86_MCE && X86_LOCAL_APIC
 792         ---help---
 793            Additional support for AMD specific MCE features such as
 794            the DRAM Error Threshold.
 795
 796 config X86_MCE_THRESHOLD
 797         depends on X86_MCE_AMD || X86_MCE_INTEL
 798         bool
 799         default y
 800
 801 config X86_MCE_NONFATAL
 802         tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
 803         depends on X86_32 && X86_MCE
 804         ---help---
 805           Enabling this feature starts a timer that triggers every 5 seconds which
 806           will look at the machine check registers to see if anything happened.
 807           Non-fatal problems automatically get corrected (but still logged).
 808           Disable this if you don't want to see these messages.
 809           Seeing the messages this option prints out may be indicative of dying
 810           or out-of-spec (ie, overclocked) hardware.
 811           This option only does something on certain CPUs.
 812           (AMD Athlon/Duron and Intel Pentium 4)
 813
 814 config X86_MCE_P4THERMAL
 815         bool "check for P4 thermal throttling interrupt."
 816         depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
 817         ---help---
 818           Enabling this feature will cause a message to be printed when the P4
 819           enters thermal throttling.
 820
 821 config VM86
 822         bool "Enable VM86 support" if EMBEDDED
 823         default y
 824         depends on X86_32
 825         ---help---
 826           This option is required by programs like DOSEMU to run 16-bit legacy
 827           code on X86 processors. It also may be needed by software like
 828           XFree86 to initialize some video cards via BIOS. Disabling this
 829           option saves about 6k.
 830
 831 config TOSHIBA
 832         tristate "Toshiba Laptop support"
 833         depends on X86_32
 834         ---help---
 835           This adds a driver to safely access the System Management Mode of
 836           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 837           not work on models with a Phoenix BIOS. The System Management Mode
 838           is used to set the BIOS and power saving options on Toshiba portables.
 839
 840           For information on utilities to make use of this driver see the
 841           Toshiba Linux utilities web site at:
 842           <http://www.buzzard.org.uk/toshiba/>.
 843
 844           Say Y if you intend to run this kernel on a Toshiba portable.
 845           Say N otherwise.
 846
 847 config I8K
 848         tristate "Dell laptop support"
 849         ---help---
 850           This adds a driver to safely access the System Management Mode
 851           of the CPU on the Dell Inspiron 8000. The System Management Mode
 852           is used to read cpu temperature and cooling fan status and to
 853           control the fans on the I8K portables.
 854
 855           This driver has been tested only on the Inspiron 8000 but it may
 856           also work with other Dell laptops. You can force loading on other
 857           models by passing the parameter `force=1' to the module. Use at
 858           your own risk.
 859
 860           For information on utilities to make use of this driver see the
 861           I8K Linux utilities web site at:
 862           <http://people.debian.org/~dz/i8k/>
 863
 864           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 865           Say N otherwise.
 866
 867 config X86_REBOOTFIXUPS
 868         bool "Enable X86 board specific fixups for reboot"
 869         depends on X86_32
 870         ---help---
 871           This enables chipset and/or board specific fixups to be done
 872           in order to get reboot to work correctly. This is only needed on
 873           some combinations of hardware and BIOS. The symptom, for which
 874           this config is intended, is when reboot ends with a stalled/hung
 875           system.
 876
 877           Currently, the only fixup is for the Geode machines using
 878           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 879
 880           Say Y if you want to enable the fixup. Currently, it's safe to
 881           enable this option even if you don't need it.
 882           Say N otherwise.
 883
 884 config MICROCODE
 885         tristate "/dev/cpu/microcode - microcode support"
 886         select FW_LOADER
 887         ---help---
 888           If you say Y here, you will be able to update the microcode on
 889           certain Intel and AMD processors. The Intel support is for the
 890           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 891           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 892           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 893           You will obviously need the actual microcode binary data itself
 894           which is not shipped with the Linux kernel.
 895
 896           This option selects the general module only, you need to select
 897           at least one vendor specific module as well.
 898
 899           To compile this driver as a module, choose M here: the
 900           module will be called microcode.
 901
 902 config MICROCODE_INTEL
 903         bool "Intel microcode patch loading support"
 904         depends on MICROCODE
 905         default MICROCODE
 906         select FW_LOADER
 907         ---help---
 908           This options enables microcode patch loading support for Intel
 909           processors.
 910
 911           For latest news and information on obtaining all the required
 912           Intel ingredients for this driver, check:
 913           <http://www.urbanmyth.org/microcode/>.
 914
 915 config MICROCODE_AMD
 916         bool "AMD microcode patch loading support"
 917         depends on MICROCODE
 918         select FW_LOADER
 919         ---help---
 920           If you select this option, microcode patch loading support for AMD
 921           processors will be enabled.
 922
 923 config MICROCODE_OLD_INTERFACE
 924         def_bool y
 925         depends on MICROCODE
 926
 927 config X86_MSR
 928         tristate "/dev/cpu/*/msr - Model-specific register support"
 929         ---help---
 930           This device gives privileged processes access to the x86
 931           Model-Specific Registers (MSRs).  It is a character device with
 932           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
 933           MSR accesses are directed to a specific CPU on multi-processor
 934           systems.
 935
 936 config X86_CPUID
 937         tristate "/dev/cpu/*/cpuid - CPU information support"
 938         ---help---
 939           This device gives processes access to the x86 CPUID instruction to
 940           be executed on a specific processor.  It is a character device
 941           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
 942           /dev/cpu/31/cpuid.
 943
 944 config X86_CPU_DEBUG
 945         tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
 946         ---help---
 947           If you select this option, this will provide various x86 CPUs
 948           information through debugfs.
 949
 950 choice
 951         prompt "High Memory Support"
 952         default HIGHMEM4G if !X86_NUMAQ
 953         default HIGHMEM64G if X86_NUMAQ
 954         depends on X86_32
 955
 956 config NOHIGHMEM
 957         bool "off"
 958         depends on !X86_NUMAQ
 959         ---help---
 960           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
 961           However, the address space of 32-bit x86 processors is only 4
 962           Gigabytes large. That means that, if you have a large amount of
 963           physical memory, not all of it can be "permanently mapped" by the
 964           kernel. The physical memory that's not permanently mapped is called
 965           "high memory".
 966
 967           If you are compiling a kernel which will never run on a machine with
 968           more than 1 Gigabyte total physical RAM, answer "off" here (default
 969           choice and suitable for most users). This will result in a "3GB/1GB"
 970           split: 3GB are mapped so that each process sees a 3GB virtual memory
 971           space and the remaining part of the 4GB virtual memory space is used
 972           by the kernel to permanently map as much physical memory as
 973           possible.
 974
 975           If the machine has between 1 and 4 Gigabytes physical RAM, then
 976           answer "4GB" here.
 977
 978           If more than 4 Gigabytes is used then answer "64GB" here. This
 979           selection turns Intel PAE (Physical Address Extension) mode on.
 980           PAE implements 3-level paging on IA32 processors. PAE is fully
 981           supported by Linux, PAE mode is implemented on all recent Intel
 982           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
 983           then the kernel will not boot on CPUs that don't support PAE!
 984
 985           The actual amount of total physical memory will either be
 986           auto detected or can be forced by using a kernel command line option
 987           such as "mem=256M". (Try "man bootparam" or see the documentation of
 988           your boot loader (lilo or loadlin) about how to pass options to the
 989           kernel at boot time.)
 990
 991           If unsure, say "off".
 992
 993 config HIGHMEM4G
 994         bool "4GB"
 995         depends on !X86_NUMAQ
 996         ---help---
 997           Select this if you have a 32-bit processor and between 1 and 4
 998           gigabytes of physical RAM.
 999
1000 config HIGHMEM64G
1001         bool "64GB"
1002         depends on !M386 && !M486
1003         select X86_PAE
1004         ---help---
1005           Select this if you have a 32-bit processor and more than 4
1006           gigabytes of physical RAM.
1007
1008 endchoice
1009
1010 choice
1011         depends on EXPERIMENTAL
1012         prompt "Memory split" if EMBEDDED
1013         default VMSPLIT_3G
1014         depends on X86_32
1015         ---help---
1016           Select the desired split between kernel and user memory.
1017
1018           If the address range available to the kernel is less than the
1019           physical memory installed, the remaining memory will be available
1020           as "high memory". Accessing high memory is a little more costly
1021           than low memory, as it needs to be mapped into the kernel first.
1022           Note that increasing the kernel address space limits the range
1023           available to user programs, making the address space there
1024           tighter.  Selecting anything other than the default 3G/1G split
1025           will also likely make your kernel incompatible with binary-only
1026           kernel modules.
1027
1028           If you are not absolutely sure what you are doing, leave this
1029           option alone!
1030
1031         config VMSPLIT_3G
1032                 bool "3G/1G user/kernel split"
1033         config VMSPLIT_3G_OPT
1034                 depends on !X86_PAE
1035                 bool "3G/1G user/kernel split (for full 1G low memory)"
1036         config VMSPLIT_2G
1037                 bool "2G/2G user/kernel split"
1038         config VMSPLIT_2G_OPT
1039                 depends on !X86_PAE
1040                 bool "2G/2G user/kernel split (for full 2G low memory)"
1041         config VMSPLIT_1G
1042                 bool "1G/3G user/kernel split"
1043 endchoice
1044
1045 config PAGE_OFFSET
1046         hex
1047         default 0xB0000000 if VMSPLIT_3G_OPT
1048         default 0x80000000 if VMSPLIT_2G
1049         default 0x78000000 if VMSPLIT_2G_OPT
1050         default 0x40000000 if VMSPLIT_1G
1051         default 0xC0000000
1052         depends on X86_32
1053
1054 config HIGHMEM
1055         def_bool y
1056         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1057
1058 config X86_PAE
1059         bool "PAE (Physical Address Extension) Support"
1060         depends on X86_32 && !HIGHMEM4G
1061         ---help---
1062           PAE is required for NX support, and furthermore enables
1063           larger swapspace support for non-overcommit purposes. It
1064           has the cost of more pagetable lookup overhead, and also
1065           consumes more pagetable space per process.
1066
1067 config ARCH_PHYS_ADDR_T_64BIT
1068         def_bool X86_64 || X86_PAE
1069
1070 config DIRECT_GBPAGES
1071         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1072         default y
1073         depends on X86_64
1074         ---help---
1075           Allow the kernel linear mapping to use 1GB pages on CPUs that
1076           support it. This can improve the kernel's performance a tiny bit by
1077           reducing TLB pressure. If in doubt, say "Y".
1078
1079 # Common NUMA Features
1080 config NUMA
1081         bool "Numa Memory Allocation and Scheduler Support"
1082         depends on SMP
1083         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1084         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1085         ---help---
1086           Enable NUMA (Non Uniform Memory Access) support.
1087
1088           The kernel will try to allocate memory used by a CPU on the
1089           local memory controller of the CPU and add some more
1090           NUMA awareness to the kernel.
1091
1092           For 64-bit this is recommended if the system is Intel Core i7
1093           (or later), AMD Opteron, or EM64T NUMA.
1094
1095           For 32-bit this is only needed on (rare) 32-bit-only platforms
1096           that support NUMA topologies, such as NUMAQ / Summit, or if you
1097           boot a 32-bit kernel on a 64-bit NUMA platform.
1098
1099           Otherwise, you should say N.
1100
1101 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1102         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1103
1104 config K8_NUMA
1105         def_bool y
1106         prompt "Old style AMD Opteron NUMA detection"
1107         depends on X86_64 && NUMA && PCI
1108         ---help---
1109           Enable K8 NUMA node topology detection.  You should say Y here if
1110           you have a multi processor AMD K8 system. This uses an old
1111           method to read the NUMA configuration directly from the builtin
1112           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1113           instead, which also takes priority if both are compiled in.
1114
1115 config X86_64_ACPI_NUMA
1116         def_bool y
1117         prompt "ACPI NUMA detection"
1118         depends on X86_64 && NUMA && ACPI && PCI
1119         select ACPI_NUMA
1120         ---help---
1121           Enable ACPI SRAT based node topology detection.
1122
1123 # Some NUMA nodes have memory ranges that span
1124 # other nodes.  Even though a pfn is valid and
1125 # between a node's start and end pfns, it may not
1126 # reside on that node.  See memmap_init_zone()
1127 # for details.
1128 config NODES_SPAN_OTHER_NODES
1129         def_bool y
1130         depends on X86_64_ACPI_NUMA
1131
1132 config NUMA_EMU
1133         bool "NUMA emulation"
1134         depends on X86_64 && NUMA
1135         ---help---
1136           Enable NUMA emulation. A flat machine will be split
1137           into virtual nodes when booted with "numa=fake=N", where N is the
1138           number of nodes. This is only useful for debugging.
1139
1140 config NODES_SHIFT
1141         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1142         range 1 9
1143         default "9" if MAXSMP
1144         default "6" if X86_64
1145         default "4" if X86_NUMAQ
1146         default "3"
1147         depends on NEED_MULTIPLE_NODES
1148         ---help---
1149           Specify the maximum number of NUMA Nodes available on the target
1150           system.  Increases memory reserved to accommodate various tables.
1151
1152 config HAVE_ARCH_BOOTMEM
1153         def_bool y
1154         depends on X86_32 && NUMA
1155
1156 config ARCH_HAVE_MEMORY_PRESENT
1157         def_bool y
1158         depends on X86_32 && DISCONTIGMEM
1159
1160 config NEED_NODE_MEMMAP_SIZE
1161         def_bool y
1162         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1163
1164 config HAVE_ARCH_ALLOC_REMAP
1165         def_bool y
1166         depends on X86_32 && NUMA
1167
1168 config ARCH_FLATMEM_ENABLE
1169         def_bool y
1170         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1171
1172 config ARCH_DISCONTIGMEM_ENABLE
1173         def_bool y
1174         depends on NUMA && X86_32
1175
1176 config ARCH_DISCONTIGMEM_DEFAULT
1177         def_bool y
1178         depends on NUMA && X86_32
1179
1180 config ARCH_SPARSEMEM_DEFAULT
1181         def_bool y
1182         depends on X86_64
1183
1184 config ARCH_SPARSEMEM_ENABLE
1185         def_bool y
1186         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1187         select SPARSEMEM_STATIC if X86_32
1188         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1189
1190 config ARCH_SELECT_MEMORY_MODEL
1191         def_bool y
1192         depends on ARCH_SPARSEMEM_ENABLE
1193
1194 config ARCH_MEMORY_PROBE
1195         def_bool X86_64
1196         depends on MEMORY_HOTPLUG
1197
1198 source "mm/Kconfig"
1199
1200 config HIGHPTE
1201         bool "Allocate 3rd-level pagetables from highmem"
1202         depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1203         ---help---
1204           The VM uses one page table entry for each page of physical memory.
1205           For systems with a lot of RAM, this can be wasteful of precious
1206           low memory.  Setting this option will put user-space page table
1207           entries in high memory.
1208
1209 config X86_CHECK_BIOS_CORRUPTION
1210         bool "Check for low memory corruption"
1211         ---help---
1212           Periodically check for memory corruption in low memory, which
1213           is suspected to be caused by BIOS.  Even when enabled in the
1214           configuration, it is disabled at runtime.  Enable it by
1215           setting "memory_corruption_check=1" on the kernel command
1216           line.  By default it scans the low 64k of memory every 60
1217           seconds; see the memory_corruption_check_size and
1218           memory_corruption_check_period parameters in
1219           Documentation/kernel-parameters.txt to adjust this.
1220
1221           When enabled with the default parameters, this option has
1222           almost no overhead, as it reserves a relatively small amount
1223           of memory and scans it infrequently.  It both detects corruption
1224           and prevents it from affecting the running system.
1225
1226           It is, however, intended as a diagnostic tool; if repeatable
1227           BIOS-originated corruption always affects the same memory,
1228           you can use memmap= to prevent the kernel from using that
1229           memory.
1230
1231 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1232         bool "Set the default setting of memory_corruption_check"
1233         depends on X86_CHECK_BIOS_CORRUPTION
1234         default y
1235         ---help---
1236           Set whether the default state of memory_corruption_check is
1237           on or off.
1238
1239 config X86_RESERVE_LOW_64K
1240         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1241         default y
1242         ---help---
1243           Reserve the first 64K of physical RAM on BIOSes that are known
1244           to potentially corrupt that memory range. A numbers of BIOSes are
1245           known to utilize this area during suspend/resume, so it must not
1246           be used by the kernel.
1247
1248           Set this to N if you are absolutely sure that you trust the BIOS
1249           to get all its memory reservations and usages right.
1250
1251           If you have doubts about the BIOS (e.g. suspend/resume does not
1252           work or there's kernel crashes after certain hardware hotplug
1253           events) and it's not AMI or Phoenix, then you might want to enable
1254           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1255           corruption patterns.
1256
1257           Say Y if unsure.
1258
1259 config MATH_EMULATION
1260         bool
1261         prompt "Math emulation" if X86_32
1262         ---help---
1263           Linux can emulate a math coprocessor (used for floating point
1264           operations) if you don't have one. 486DX and Pentium processors have
1265           a math coprocessor built in, 486SX and 386 do not, unless you added
1266           a 487DX or 387, respectively. (The messages during boot time can
1267           give you some hints here ["man dmesg"].) Everyone needs either a
1268           coprocessor or this emulation.
1269
1270           If you don't have a math coprocessor, you need to say Y here; if you
1271           say Y here even though you have a coprocessor, the coprocessor will
1272           be used nevertheless. (This behavior can be changed with the kernel
1273           command line option "no387", which comes handy if your coprocessor
1274           is broken. Try "man bootparam" or see the documentation of your boot
1275           loader (lilo or loadlin) about how to pass options to the kernel at
1276           boot time.) This means that it is a good idea to say Y here if you
1277           intend to use this kernel on different machines.
1278
1279           More information about the internals of the Linux math coprocessor
1280           emulation can be found in <file:arch/x86/math-emu/README>.
1281
1282           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1283           kernel, it won't hurt.
1284
1285 config MTRR
1286         bool "MTRR (Memory Type Range Register) support"
1287         ---help---
1288           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1289           the Memory Type Range Registers (MTRRs) may be used to control
1290           processor access to memory ranges. This is most useful if you have
1291           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1292           allows bus write transfers to be combined into a larger transfer
1293           before bursting over the PCI/AGP bus. This can increase performance
1294           of image write operations 2.5 times or more. Saying Y here creates a
1295           /proc/mtrr file which may be used to manipulate your processor's
1296           MTRRs. Typically the X server should use this.
1297
1298           This code has a reasonably generic interface so that similar
1299           control registers on other processors can be easily supported
1300           as well:
1301
1302           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1303           Registers (ARRs) which provide a similar functionality to MTRRs. For
1304           these, the ARRs are used to emulate the MTRRs.
1305           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1306           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1307           write-combining. All of these processors are supported by this code
1308           and it makes sense to say Y here if you have one of them.
1309
1310           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1311           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1312           can lead to all sorts of problems, so it's good to say Y here.
1313
1314           You can safely say Y even if your machine doesn't have MTRRs, you'll
1315           just add about 9 KB to your kernel.
1316
1317           See <file:Documentation/x86/mtrr.txt> for more information.
1318
1319 config MTRR_SANITIZER
1320         def_bool y
1321         prompt "MTRR cleanup support"
1322         depends on MTRR
1323         ---help---
1324           Convert MTRR layout from continuous to discrete, so X drivers can
1325           add writeback entries.
1326
1327           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1328           The largest mtrr entry size for a continuous block can be set with
1329           mtrr_chunk_size.
1330
1331           If unsure, say Y.
1332
1333 config MTRR_SANITIZER_ENABLE_DEFAULT
1334         int "MTRR cleanup enable value (0-1)"
1335         range 0 1
1336         default "0"
1337         depends on MTRR_SANITIZER
1338         ---help---
1339           Enable mtrr cleanup default value
1340
1341 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1342         int "MTRR cleanup spare reg num (0-7)"
1343         range 0 7
1344         default "1"
1345         depends on MTRR_SANITIZER
1346         ---help---
1347           mtrr cleanup spare entries default, it can be changed via
1348           mtrr_spare_reg_nr=N on the kernel command line.
1349
1350 config X86_PAT
1351         bool
1352         prompt "x86 PAT support"
1353         depends on MTRR
1354         ---help---
1355           Use PAT attributes to setup page level cache control.
1356
1357           PATs are the modern equivalents of MTRRs and are much more
1358           flexible than MTRRs.
1359
1360           Say N here if you see bootup problems (boot crash, boot hang,
1361           spontaneous reboots) or a non-working video driver.
1362
1363           If unsure, say Y.
1364
1365 config EFI
1366         bool "EFI runtime service support"
1367         depends on ACPI
1368         ---help---
1369           This enables the kernel to use EFI runtime services that are
1370           available (such as the EFI variable services).
1371
1372           This option is only useful on systems that have EFI firmware.
1373           In addition, you should use the latest ELILO loader available
1374           at <http://elilo.sourceforge.net> in order to take advantage
1375           of EFI runtime services. However, even with this option, the
1376           resultant kernel should continue to boot on existing non-EFI
1377           platforms.
1378
1379 config SECCOMP
1380         def_bool y
1381         prompt "Enable seccomp to safely compute untrusted bytecode"
1382         ---help---
1383           This kernel feature is useful for number crunching applications
1384           that may need to compute untrusted bytecode during their
1385           execution. By using pipes or other transports made available to
1386           the process as file descriptors supporting the read/write
1387           syscalls, it's possible to isolate those applications in
1388           their own address space using seccomp. Once seccomp is
1389           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1390           and the task is only allowed to execute a few safe syscalls
1391           defined by each seccomp mode.
1392
1393           If unsure, say Y. Only embedded should say N here.
1394
1395 config CC_STACKPROTECTOR_ALL
1396         bool
1397
1398 config CC_STACKPROTECTOR
1399         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1400         select CC_STACKPROTECTOR_ALL
1401         ---help---
1402           This option turns on the -fstack-protector GCC feature. This
1403           feature puts, at the beginning of functions, a canary value on
1404           the stack just before the return address, and validates
1405           the value just before actually returning.  Stack based buffer
1406           overflows (that need to overwrite this return address) now also
1407           overwrite the canary, which gets detected and the attack is then
1408           neutralized via a kernel panic.
1409
1410           This feature requires gcc version 4.2 or above, or a distribution
1411           gcc with the feature backported. Older versions are automatically
1412           detected and for those versions, this configuration option is
1413           ignored. (and a warning is printed during bootup)
1414
1415 source kernel/Kconfig.hz
1416
1417 config KEXEC
1418         bool "kexec system call"
1419         ---help---
1420           kexec is a system call that implements the ability to shutdown your
1421           current kernel, and to start another kernel.  It is like a reboot
1422           but it is independent of the system firmware.   And like a reboot
1423           you can start any kernel with it, not just Linux.
1424
1425           The name comes from the similarity to the exec system call.
1426
1427           It is an ongoing process to be certain the hardware in a machine
1428           is properly shutdown, so do not be surprised if this code does not
1429           initially work for you.  It may help to enable device hotplugging
1430           support.  As of this writing the exact hardware interface is
1431           strongly in flux, so no good recommendation can be made.
1432
1433 config CRASH_DUMP
1434         bool "kernel crash dumps"
1435         depends on X86_64 || (X86_32 && HIGHMEM)
1436         ---help---
1437           Generate crash dump after being started by kexec.
1438           This should be normally only set in special crash dump kernels
1439           which are loaded in the main kernel with kexec-tools into
1440           a specially reserved region and then later executed after
1441           a crash by kdump/kexec. The crash dump kernel must be compiled
1442           to a memory address not used by the main kernel or BIOS using
1443           PHYSICAL_START, or it must be built as a relocatable image
1444           (CONFIG_RELOCATABLE=y).
1445           For more details see Documentation/kdump/kdump.txt
1446
1447 config KEXEC_JUMP
1448         bool "kexec jump (EXPERIMENTAL)"
1449         depends on EXPERIMENTAL
1450         depends on KEXEC && HIBERNATION
1451         ---help---
1452           Jump between original kernel and kexeced kernel and invoke
1453           code in physical address mode via KEXEC
1454
1455 config PHYSICAL_START
1456         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1457         default "0x1000000" if X86_NUMAQ
1458         default "0x200000" if X86_64
1459         default "0x100000"
1460         ---help---
1461           This gives the physical address where the kernel is loaded.
1462
1463           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1464           bzImage will decompress itself to above physical address and
1465           run from there. Otherwise, bzImage will run from the address where
1466           it has been loaded by the boot loader and will ignore above physical
1467           address.
1468
1469           In normal kdump cases one does not have to set/change this option
1470           as now bzImage can be compiled as a completely relocatable image
1471           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1472           address. This option is mainly useful for the folks who don't want
1473           to use a bzImage for capturing the crash dump and want to use a
1474           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1475           to be specifically compiled to run from a specific memory area
1476           (normally a reserved region) and this option comes handy.
1477
1478           So if you are using bzImage for capturing the crash dump, leave
1479           the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1480           Otherwise if you plan to use vmlinux for capturing the crash dump
1481           change this value to start of the reserved region (Typically 16MB
1482           0x1000000). In other words, it can be set based on the "X" value as
1483           specified in the "crashkernel=YM@XM" command line boot parameter
1484           passed to the panic-ed kernel. Typically this parameter is set as
1485           crashkernel=64M@16M. Please take a look at
1486           Documentation/kdump/kdump.txt for more details about crash dumps.
1487
1488           Usage of bzImage for capturing the crash dump is recommended as
1489           one does not have to build two kernels. Same kernel can be used
1490           as production kernel and capture kernel. Above option should have
1491           gone away after relocatable bzImage support is introduced. But it
1492           is present because there are users out there who continue to use
1493           vmlinux for dump capture. This option should go away down the
1494           line.
1495
1496           Don't change this unless you know what you are doing.
1497
1498 config RELOCATABLE
1499         bool "Build a relocatable kernel (EXPERIMENTAL)"
1500         depends on EXPERIMENTAL
1501         ---help---
1502           This builds a kernel image that retains relocation information
1503           so it can be loaded someplace besides the default 1MB.
1504           The relocations tend to make the kernel binary about 10% larger,
1505           but are discarded at runtime.
1506
1507           One use is for the kexec on panic case where the recovery kernel
1508           must live at a different physical address than the primary
1509           kernel.
1510
1511           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1512           it has been loaded at and the compile time physical address
1513           (CONFIG_PHYSICAL_START) is ignored.
1514
1515 config PHYSICAL_ALIGN
1516         hex
1517         prompt "Alignment value to which kernel should be aligned" if X86_32
1518         default "0x100000" if X86_32
1519         default "0x200000" if X86_64
1520         range 0x2000 0x400000
1521         ---help---
1522           This value puts the alignment restrictions on physical address
1523           where kernel is loaded and run from. Kernel is compiled for an
1524           address which meets above alignment restriction.
1525
1526           If bootloader loads the kernel at a non-aligned address and
1527           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1528           address aligned to above value and run from there.
1529
1530           If bootloader loads the kernel at a non-aligned address and
1531           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1532           load address and decompress itself to the address it has been
1533           compiled for and run from there. The address for which kernel is
1534           compiled already meets above alignment restrictions. Hence the
1535           end result is that kernel runs from a physical address meeting
1536           above alignment restrictions.
1537
1538           Don't change this unless you know what you are doing.
1539
1540 config HOTPLUG_CPU
1541         bool "Support for hot-pluggable CPUs"
1542         depends on SMP && HOTPLUG
1543         ---help---
1544           Say Y here to allow turning CPUs off and on. CPUs can be
1545           controlled through /sys/devices/system/cpu.
1546           ( Note: power management support will enable this option
1547             automatically on SMP systems. )
1548           Say N if you want to disable CPU hotplug.
1549
1550 config COMPAT_VDSO
1551         def_bool y
1552         prompt "Compat VDSO support"
1553         depends on X86_32 || IA32_EMULATION
1554         ---help---
1555           Map the 32-bit VDSO to the predictable old-style address too.
1556         ---help---
1557           Say N here if you are running a sufficiently recent glibc
1558           version (2.3.3 or later), to remove the high-mapped
1559           VDSO mapping and to exclusively use the randomized VDSO.
1560
1561           If unsure, say Y.
1562
1563 config CMDLINE_BOOL
1564         bool "Built-in kernel command line"
1565         default n
1566         ---help---
1567           Allow for specifying boot arguments to the kernel at
1568           build time.  On some systems (e.g. embedded ones), it is
1569           necessary or convenient to provide some or all of the
1570           kernel boot arguments with the kernel itself (that is,
1571           to not rely on the boot loader to provide them.)
1572
1573           To compile command line arguments into the kernel,
1574           set this option to 'Y', then fill in the
1575           the boot arguments in CONFIG_CMDLINE.
1576
1577           Systems with fully functional boot loaders (i.e. non-embedded)
1578           should leave this option set to 'N'.
1579
1580 config CMDLINE
1581         string "Built-in kernel command string"
1582         depends on CMDLINE_BOOL
1583         default ""
1584         ---help---
1585           Enter arguments here that should be compiled into the kernel
1586           image and used at boot time.  If the boot loader provides a
1587           command line at boot time, it is appended to this string to
1588           form the full kernel command line, when the system boots.
1589
1590           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1591           change this behavior.
1592
1593           In most cases, the command line (whether built-in or provided
1594           by the boot loader) should specify the device for the root
1595           file system.
1596
1597 config CMDLINE_OVERRIDE
1598         bool "Built-in command line overrides boot loader arguments"
1599         default n
1600         depends on CMDLINE_BOOL
1601         ---help---
1602           Set this option to 'Y' to have the kernel ignore the boot loader
1603           command line, and use ONLY the built-in command line.
1604
1605           This is used to work around broken boot loaders.  This should
1606           be set to 'N' under normal conditions.
1607
1608 endmenu
1609
1610 config ARCH_ENABLE_MEMORY_HOTPLUG
1611         def_bool y
1612         depends on X86_64 || (X86_32 && HIGHMEM)
1613
1614 config ARCH_ENABLE_MEMORY_HOTREMOVE
1615         def_bool y
1616         depends on MEMORY_HOTPLUG
1617
1618 config HAVE_ARCH_EARLY_PFN_TO_NID
1619         def_bool X86_64
1620         depends on NUMA
1621
1622 menu "Power management and ACPI options"
1623
1624 config ARCH_HIBERNATION_HEADER
1625         def_bool y
1626         depends on X86_64 && HIBERNATION
1627
1628 source "kernel/power/Kconfig"
1629
1630 source "drivers/acpi/Kconfig"
1631
1632 config X86_APM_BOOT
1633         bool
1634         default y
1635         depends on APM || APM_MODULE
1636
1637 menuconfig APM
1638         tristate "APM (Advanced Power Management) BIOS support"
1639         depends on X86_32 && PM_SLEEP
1640         ---help---
1641           APM is a BIOS specification for saving power using several different
1642           techniques. This is mostly useful for battery powered laptops with
1643           APM compliant BIOSes. If you say Y here, the system time will be
1644           reset after a RESUME operation, the /proc/apm device will provide
1645           battery status information, and user-space programs will receive
1646           notification of APM "events" (e.g. battery status change).
1647
1648           If you select "Y" here, you can disable actual use of the APM
1649           BIOS by passing the "apm=off" option to the kernel at boot time.
1650
1651           Note that the APM support is almost completely disabled for
1652           machines with more than one CPU.
1653
1654           In order to use APM, you will need supporting software. For location
1655           and more information, read <file:Documentation/power/pm.txt> and the
1656           Battery Powered Linux mini-HOWTO, available from
1657           <http://www.tldp.org/docs.html#howto>.
1658
1659           This driver does not spin down disk drives (see the hdparm(8)
1660           manpage ("man 8 hdparm") for that), and it doesn't turn off
1661           VESA-compliant "green" monitors.
1662
1663           This driver does not support the TI 4000M TravelMate and the ACER
1664           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1665           desktop machines also don't have compliant BIOSes, and this driver
1666           may cause those machines to panic during the boot phase.
1667
1668           Generally, if you don't have a battery in your machine, there isn't
1669           much point in using this driver and you should say N. If you get
1670           random kernel OOPSes or reboots that don't seem to be related to
1671           anything, try disabling/enabling this option (or disabling/enabling
1672           APM in your BIOS).
1673
1674           Some other things you should try when experiencing seemingly random,
1675           "weird" problems:
1676
1677           1) make sure that you have enough swap space and that it is
1678           enabled.
1679           2) pass the "no-hlt" option to the kernel
1680           3) switch on floating point emulation in the kernel and pass
1681           the "no387" option to the kernel
1682           4) pass the "floppy=nodma" option to the kernel
1683           5) pass the "mem=4M" option to the kernel (thereby disabling
1684           all but the first 4 MB of RAM)
1685           6) make sure that the CPU is not over clocked.
1686           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1687           8) disable the cache from your BIOS settings
1688           9) install a fan for the video card or exchange video RAM
1689           10) install a better fan for the CPU
1690           11) exchange RAM chips
1691           12) exchange the motherboard.
1692
1693           To compile this driver as a module, choose M here: the
1694           module will be called apm.
1695
1696 if APM
1697
1698 config APM_IGNORE_USER_SUSPEND
1699         bool "Ignore USER SUSPEND"
1700         ---help---
1701           This option will ignore USER SUSPEND requests. On machines with a
1702           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1703           series notebooks, it is necessary to say Y because of a BIOS bug.
1704
1705 config APM_DO_ENABLE
1706         bool "Enable PM at boot time"
1707         ---help---
1708           Enable APM features at boot time. From page 36 of the APM BIOS
1709           specification: "When disabled, the APM BIOS does not automatically
1710           power manage devices, enter the Standby State, enter the Suspend
1711           State, or take power saving steps in response to CPU Idle calls."
1712           This driver will make CPU Idle calls when Linux is idle (unless this
1713           feature is turned off -- see "Do CPU IDLE calls", below). This
1714           should always save battery power, but more complicated APM features
1715           will be dependent on your BIOS implementation. You may need to turn
1716           this option off if your computer hangs at boot time when using APM
1717           support, or if it beeps continuously instead of suspending. Turn
1718           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1719           T400CDT. This is off by default since most machines do fine without
1720           this feature.
1721
1722 config APM_CPU_IDLE
1723         bool "Make CPU Idle calls when idle"
1724         ---help---
1725           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1726           On some machines, this can activate improved power savings, such as
1727           a slowed CPU clock rate, when the machine is idle. These idle calls
1728           are made after the idle loop has run for some length of time (e.g.,
1729           333 mS). On some machines, this will cause a hang at boot time or
1730           whenever the CPU becomes idle. (On machines with more than one CPU,
1731           this option does nothing.)
1732
1733 config APM_DISPLAY_BLANK
1734         bool "Enable console blanking using APM"
1735         ---help---
1736           Enable console blanking using the APM. Some laptops can use this to
1737           turn off the LCD backlight when the screen blanker of the Linux
1738           virtual console blanks the screen. Note that this is only used by
1739           the virtual console screen blanker, and won't turn off the backlight
1740           when using the X Window system. This also doesn't have anything to
1741           do with your VESA-compliant power-saving monitor. Further, this
1742           option doesn't work for all laptops -- it might not turn off your
1743           backlight at all, or it might print a lot of errors to the console,
1744           especially if you are using gpm.
1745
1746 config APM_ALLOW_INTS
1747         bool "Allow interrupts during APM BIOS calls"
1748         ---help---
1749           Normally we disable external interrupts while we are making calls to
1750           the APM BIOS as a measure to lessen the effects of a badly behaving
1751           BIOS implementation.  The BIOS should reenable interrupts if it
1752           needs to.  Unfortunately, some BIOSes do not -- especially those in
1753           many of the newer IBM Thinkpads.  If you experience hangs when you
1754           suspend, try setting this to Y.  Otherwise, say N.
1755
1756 endif # APM
1757
1758 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1759
1760 source "drivers/cpuidle/Kconfig"
1761
1762 source "drivers/idle/Kconfig"
1763
1764 endmenu
1765
1766
1767 menu "Bus options (PCI etc.)"
1768
1769 config PCI
1770         bool "PCI support"
1771         default y
1772         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1773         ---help---
1774           Find out whether you have a PCI motherboard. PCI is the name of a
1775           bus system, i.e. the way the CPU talks to the other stuff inside
1776           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1777           VESA. If you have PCI, say Y, otherwise N.
1778
1779 choice
1780         prompt "PCI access mode"
1781         depends on X86_32 && PCI
1782         default PCI_GOANY
1783         ---help---
1784           On PCI systems, the BIOS can be used to detect the PCI devices and
1785           determine their configuration. However, some old PCI motherboards
1786           have BIOS bugs and may crash if this is done. Also, some embedded
1787           PCI-based systems don't have any BIOS at all. Linux can also try to
1788           detect the PCI hardware directly without using the BIOS.
1789
1790           With this option, you can specify how Linux should detect the
1791           PCI devices. If you choose "BIOS", the BIOS will be used,
1792           if you choose "Direct", the BIOS won't be used, and if you
1793           choose "MMConfig", then PCI Express MMCONFIG will be used.
1794           If you choose "Any", the kernel will try MMCONFIG, then the
1795           direct access method and falls back to the BIOS if that doesn't
1796           work. If unsure, go with the default, which is "Any".
1797
1798 config PCI_GOBIOS
1799         bool "BIOS"
1800
1801 config PCI_GOMMCONFIG
1802         bool "MMConfig"
1803
1804 config PCI_GODIRECT
1805         bool "Direct"
1806
1807 config PCI_GOOLPC
1808         bool "OLPC"
1809         depends on OLPC
1810
1811 config PCI_GOANY
1812         bool "Any"
1813
1814 endchoice
1815
1816 config PCI_BIOS
1817         def_bool y
1818         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1819
1820 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1821 config PCI_DIRECT
1822         def_bool y
1823         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1824
1825 config PCI_MMCONFIG
1826         def_bool y
1827         depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1828
1829 config PCI_OLPC
1830         def_bool y
1831         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1832
1833 config PCI_DOMAINS
1834         def_bool y
1835         depends on PCI
1836
1837 config PCI_MMCONFIG
1838         bool "Support mmconfig PCI config space access"
1839         depends on X86_64 && PCI && ACPI
1840
1841 config DMAR
1842         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1843         depends on PCI_MSI && ACPI && EXPERIMENTAL
1844         help
1845           DMA remapping (DMAR) devices support enables independent address
1846           translations for Direct Memory Access (DMA) from devices.
1847           These DMA remapping devices are reported via ACPI tables
1848           and include PCI device scope covered by these DMA
1849           remapping devices.
1850
1851 config DMAR_DEFAULT_ON
1852         def_bool y
1853         prompt "Enable DMA Remapping Devices by default"
1854         depends on DMAR
1855         help
1856           Selecting this option will enable a DMAR device at boot time if
1857           one is found. If this option is not selected, DMAR support can
1858           be enabled by passing intel_iommu=on to the kernel. It is
1859           recommended you say N here while the DMAR code remains
1860           experimental.
1861
1862 config DMAR_GFX_WA
1863         def_bool y
1864         prompt "Support for Graphics workaround"
1865         depends on DMAR
1866         ---help---
1867           Current Graphics drivers tend to use physical address
1868           for DMA and avoid using DMA APIs. Setting this config
1869           option permits the IOMMU driver to set a unity map for
1870           all the OS-visible memory. Hence the driver can continue
1871           to use physical addresses for DMA.
1872
1873 config DMAR_FLOPPY_WA
1874         def_bool y
1875         depends on DMAR
1876         ---help---
1877           Floppy disk drivers are know to bypass DMA API calls
1878           thereby failing to work when IOMMU is enabled. This
1879           workaround will setup a 1:1 mapping for the first
1880           16M to make floppy (an ISA device) work.
1881
1882 config INTR_REMAP
1883         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1884         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1885         ---help---
1886           Supports Interrupt remapping for IO-APIC and MSI devices.
1887           To use x2apic mode in the CPU's which support x2APIC enhancements or
1888           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1889
1890 source "drivers/pci/pcie/Kconfig"
1891
1892 source "drivers/pci/Kconfig"
1893
1894 # x86_64 have no ISA slots, but do have ISA-style DMA.
1895 config ISA_DMA_API
1896         def_bool y
1897
1898 if X86_32
1899
1900 config ISA
1901         bool "ISA support"
1902         ---help---
1903           Find out whether you have ISA slots on your motherboard.  ISA is the
1904           name of a bus system, i.e. the way the CPU talks to the other stuff
1905           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1906           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1907           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1908
1909 config EISA
1910         bool "EISA support"
1911         depends on ISA
1912         ---help---
1913           The Extended Industry Standard Architecture (EISA) bus was
1914           developed as an open alternative to the IBM MicroChannel bus.
1915
1916           The EISA bus provided some of the features of the IBM MicroChannel
1917           bus while maintaining backward compatibility with cards made for
1918           the older ISA bus.  The EISA bus saw limited use between 1988 and
1919           1995 when it was made obsolete by the PCI bus.
1920
1921           Say Y here if you are building a kernel for an EISA-based machine.
1922
1923           Otherwise, say N.
1924
1925 source "drivers/eisa/Kconfig"
1926
1927 config MCA
1928         bool "MCA support"
1929         ---help---
1930           MicroChannel Architecture is found in some IBM PS/2 machines and
1931           laptops.  It is a bus system similar to PCI or ISA. See
1932           <file:Documentation/mca.txt> (and especially the web page given
1933           there) before attempting to build an MCA bus kernel.
1934
1935 source "drivers/mca/Kconfig"
1936
1937 config SCx200
1938         tristate "NatSemi SCx200 support"
1939         ---help---
1940           This provides basic support for National Semiconductor's
1941           (now AMD's) Geode processors.  The driver probes for the
1942           PCI-IDs of several on-chip devices, so its a good dependency
1943           for other scx200_* drivers.
1944
1945           If compiled as a module, the driver is named scx200.
1946
1947 config SCx200HR_TIMER
1948         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1949         depends on SCx200 && GENERIC_TIME
1950         default y
1951         ---help---
1952           This driver provides a clocksource built upon the on-chip
1953           27MHz high-resolution timer.  Its also a workaround for
1954           NSC Geode SC-1100's buggy TSC, which loses time when the
1955           processor goes idle (as is done by the scheduler).  The
1956           other workaround is idle=poll boot option.
1957
1958 config GEODE_MFGPT_TIMER
1959         def_bool y
1960         prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1961         depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1962         ---help---
1963           This driver provides a clock event source based on the MFGPT
1964           timer(s) in the CS5535 and CS5536 companion chip for the geode.
1965           MFGPTs have a better resolution and max interval than the
1966           generic PIT, and are suitable for use as high-res timers.
1967
1968 config OLPC
1969         bool "One Laptop Per Child support"
1970         default n
1971         ---help---
1972           Add support for detecting the unique features of the OLPC
1973           XO hardware.
1974
1975 endif # X86_32
1976
1977 config K8_NB
1978         def_bool y
1979         depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1980
1981 source "drivers/pcmcia/Kconfig"
1982
1983 source "drivers/pci/hotplug/Kconfig"
1984
1985 endmenu
1986
1987
1988 menu "Executable file formats / Emulations"
1989
1990 source "fs/Kconfig.binfmt"
1991
1992 config IA32_EMULATION
1993         bool "IA32 Emulation"
1994         depends on X86_64
1995         select COMPAT_BINFMT_ELF
1996         ---help---
1997           Include code to run 32-bit programs under a 64-bit kernel. You should
1998           likely turn this on, unless you're 100% sure that you don't have any
1999           32-bit programs left.
2000
2001 config IA32_AOUT
2002         tristate "IA32 a.out support"
2003         depends on IA32_EMULATION
2004         ---help---
2005           Support old a.out binaries in the 32bit emulation.
2006
2007 config COMPAT
2008         def_bool y
2009         depends on IA32_EMULATION
2010
2011 config COMPAT_FOR_U64_ALIGNMENT
2012         def_bool COMPAT
2013         depends on X86_64
2014
2015 config SYSVIPC_COMPAT
2016         def_bool y
2017         depends on COMPAT && SYSVIPC
2018
2019 endmenu
2020
2021
2022 config HAVE_ATOMIC_IOMAP
2023         def_bool y
2024         depends on X86_32
2025
2026 source "net/Kconfig"
2027
2028 source "drivers/Kconfig"
2029
2030 source "drivers/firmware/Kconfig"
2031
2032 source "fs/Kconfig"
2033
2034 source "arch/x86/Kconfig.debug"
2035
2036 source "security/Kconfig"
2037
2038 source "crypto/Kconfig"
2039
2040 source "arch/x86/kvm/Kconfig"
2041
2042 source "lib/Kconfig"