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