arch/x86/Kconfig

   1 # x86 configuration
   2 mainmenu "Linux Kernel Configuration for x86"
   3
   4 # Select 32 or 64 bit
   5 config 64BIT
   6         bool "64-bit kernel" if ARCH = "x86"
   7         default ARCH = "x86_64"
   8         ---help---
   9           Say yes to build a 64-bit kernel - formerly known as x86_64
  10           Say no to build a 32-bit kernel - formerly known as i386
  11
  12 config X86_32
  13         def_bool !64BIT
  14
  15 config X86_64
  16         def_bool 64BIT
  17
  18 ### Arch settings
  19 config X86
  20         def_bool y
  21         select HAVE_AOUT if X86_32
  22         select HAVE_READQ
  23         select HAVE_WRITEQ
  24         select HAVE_UNSTABLE_SCHED_CLOCK
  25         select HAVE_IDE
  26         select HAVE_OPROFILE
  27         select HAVE_PERF_EVENTS if (!M386 && !M486)
  28         select HAVE_IOREMAP_PROT
  29         select HAVE_KPROBES
  30         select ARCH_WANT_OPTIONAL_GPIOLIB
  31         select ARCH_WANT_FRAME_POINTERS
  32         select HAVE_DMA_ATTRS
  33         select HAVE_KRETPROBES
  34         select HAVE_FTRACE_MCOUNT_RECORD
  35         select HAVE_DYNAMIC_FTRACE
  36         select HAVE_FUNCTION_TRACER
  37         select HAVE_FUNCTION_GRAPH_TRACER
  38         select HAVE_FUNCTION_GRAPH_FP_TEST
  39         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  40         select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  41         select HAVE_SYSCALL_TRACEPOINTS
  42         select HAVE_KVM
  43         select HAVE_ARCH_KGDB
  44         select HAVE_ARCH_TRACEHOOK
  45         select HAVE_GENERIC_DMA_COHERENT if X86_32
  46         select HAVE_EFFICIENT_UNALIGNED_ACCESS
  47         select USER_STACKTRACE_SUPPORT
  48         select HAVE_DMA_API_DEBUG
  49         select HAVE_KERNEL_GZIP
  50         select HAVE_KERNEL_BZIP2
  51         select HAVE_KERNEL_LZMA
  52         select HAVE_HW_BREAKPOINT
  53         select HAVE_ARCH_KMEMCHECK
  54
  55 config OUTPUT_FORMAT
  56         string
  57         default "elf32-i386" if X86_32
  58         default "elf64-x86-64" if X86_64
  59
  60 config ARCH_DEFCONFIG
  61         string
  62         default "arch/x86/configs/i386_defconfig" if X86_32
  63         default "arch/x86/configs/x86_64_defconfig" if X86_64
  64
  65 config GENERIC_TIME
  66         def_bool y
  67
  68 config GENERIC_CMOS_UPDATE
  69         def_bool y
  70
  71 config CLOCKSOURCE_WATCHDOG
  72         def_bool y
  73
  74 config GENERIC_CLOCKEVENTS
  75         def_bool y
  76
  77 config GENERIC_CLOCKEVENTS_BROADCAST
  78         def_bool y
  79         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  80
  81 config LOCKDEP_SUPPORT
  82         def_bool y
  83
  84 config STACKTRACE_SUPPORT
  85         def_bool y
  86
  87 config HAVE_LATENCYTOP_SUPPORT
  88         def_bool y
  89
  90 config MMU
  91         def_bool y
  92
  93 config ZONE_DMA
  94         def_bool y
  95
  96 config SBUS
  97         bool
  98
  99 config GENERIC_ISA_DMA
 100         def_bool y
 101
 102 config GENERIC_IOMAP
 103         def_bool y
 104
 105 config GENERIC_BUG
 106         def_bool y
 107         depends on BUG
 108         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 109
 110 config GENERIC_BUG_RELATIVE_POINTERS
 111         bool
 112
 113 config GENERIC_HWEIGHT
 114         def_bool y
 115
 116 config GENERIC_GPIO
 117         bool
 118
 119 config ARCH_MAY_HAVE_PC_FDC
 120         def_bool y
 121
 122 config RWSEM_GENERIC_SPINLOCK
 123         def_bool !X86_XADD
 124
 125 config RWSEM_XCHGADD_ALGORITHM
 126         def_bool X86_XADD
 127
 128 config ARCH_HAS_CPU_IDLE_WAIT
 129         def_bool y
 130
 131 config GENERIC_CALIBRATE_DELAY
 132         def_bool y
 133
 134 config GENERIC_TIME_VSYSCALL
 135         bool
 136         default X86_64
 137
 138 config ARCH_HAS_CPU_RELAX
 139         def_bool y
 140
 141 config ARCH_HAS_DEFAULT_IDLE
 142         def_bool y
 143
 144 config ARCH_HAS_CACHE_LINE_SIZE
 145         def_bool y
 146
 147 config HAVE_SETUP_PER_CPU_AREA
 148         def_bool y
 149
 150 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 151         def_bool y
 152
 153 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 154         def_bool y
 155
 156 config HAVE_CPUMASK_OF_CPU_MAP
 157         def_bool X86_64_SMP
 158
 159 config ARCH_HIBERNATION_POSSIBLE
 160         def_bool y
 161
 162 config ARCH_SUSPEND_POSSIBLE
 163         def_bool y
 164
 165 config ZONE_DMA32
 166         bool
 167         default X86_64
 168
 169 config ARCH_POPULATES_NODE_MAP
 170         def_bool y
 171
 172 config AUDIT_ARCH
 173         bool
 174         default X86_64
 175
 176 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 177         def_bool y
 178
 179 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 180         def_bool y
 181
 182 config HAVE_INTEL_TXT
 183         def_bool y
 184         depends on EXPERIMENTAL && DMAR && ACPI
 185
 186 # Use the generic interrupt handling code in kernel/irq/:
 187 config GENERIC_HARDIRQS
 188         bool
 189         default y
 190
 191 config GENERIC_HARDIRQS_NO__DO_IRQ
 192        def_bool y
 193
 194 config GENERIC_IRQ_PROBE
 195         bool
 196         default y
 197
 198 config GENERIC_PENDING_IRQ
 199         bool
 200         depends on GENERIC_HARDIRQS && SMP
 201         default y
 202
 203 config USE_GENERIC_SMP_HELPERS
 204         def_bool y
 205         depends on SMP
 206
 207 config X86_32_SMP
 208         def_bool y
 209         depends on X86_32 && SMP
 210
 211 config X86_64_SMP
 212         def_bool y
 213         depends on X86_64 && SMP
 214
 215 config X86_HT
 216         bool
 217         depends on SMP
 218         default y
 219
 220 config X86_TRAMPOLINE
 221         bool
 222         depends on SMP || (64BIT && ACPI_SLEEP)
 223         default y
 224
 225 config X86_32_LAZY_GS
 226         def_bool y
 227         depends on X86_32 && !CC_STACKPROTECTOR
 228
 229 config KTIME_SCALAR
 230         def_bool X86_32
 231 source "init/Kconfig"
 232 source "kernel/Kconfig.freezer"
 233
 234 menu "Processor type and features"
 235
 236 source "kernel/time/Kconfig"
 237
 238 config SMP
 239         bool "Symmetric multi-processing support"
 240         ---help---
 241           This enables support for systems with more than one CPU. If you have
 242           a system with only one CPU, like most personal computers, say N. If
 243           you have a system with more than one CPU, say Y.
 244
 245           If you say N here, the kernel will run on single and multiprocessor
 246           machines, but will use only one CPU of a multiprocessor machine. If
 247           you say Y here, the kernel will run on many, but not all,
 248           singleprocessor machines. On a singleprocessor machine, the kernel
 249           will run faster if you say N here.
 250
 251           Note that if you say Y here and choose architecture "586" or
 252           "Pentium" under "Processor family", the kernel will not work on 486
 253           architectures. Similarly, multiprocessor kernels for the "PPro"
 254           architecture may not work on all Pentium based boards.
 255
 256           People using multiprocessor machines who say Y here should also say
 257           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 258           Management" code will be disabled if you say Y here.
 259
 260           See also <file:Documentation/i386/IO-APIC.txt>,
 261           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 262           <http://www.tldp.org/docs.html#howto>.
 263
 264           If you don't know what to do here, say N.
 265
 266 config X86_X2APIC
 267         bool "Support x2apic"
 268         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 269         ---help---
 270           This enables x2apic support on CPUs that have this feature.
 271
 272           This allows 32-bit apic IDs (so it can support very large systems),
 273           and accesses the local apic via MSRs not via mmio.
 274
 275           If you don't know what to do here, say N.
 276
 277 config SPARSE_IRQ
 278         bool "Support sparse irq numbering"
 279         depends on PCI_MSI || HT_IRQ
 280         ---help---
 281           This enables support for sparse irqs. This is useful for distro
 282           kernels that want to define a high CONFIG_NR_CPUS value but still
 283           want to have low kernel memory footprint on smaller machines.
 284
 285           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 286             out the irq_desc[] array in a more NUMA-friendly way. )
 287
 288           If you don't know what to do here, say N.
 289
 290 config NUMA_IRQ_DESC
 291         def_bool y
 292         depends on SPARSE_IRQ && NUMA
 293
 294 config X86_MPPARSE
 295         bool "Enable MPS table" if ACPI
 296         default y
 297         depends on X86_LOCAL_APIC
 298         ---help---
 299           For old smp systems that do not have proper acpi support. Newer systems
 300           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 301
 302 config X86_BIGSMP
 303         bool "Support for big SMP systems with more than 8 CPUs"
 304         depends on X86_32 && SMP
 305         ---help---
 306           This option is needed for the systems that have more than 8 CPUs
 307
 308 if X86_32
 309 config X86_EXTENDED_PLATFORM
 310         bool "Support for extended (non-PC) x86 platforms"
 311         default y
 312         ---help---
 313           If you disable this option then the kernel will only support
 314           standard PC platforms. (which covers the vast majority of
 315           systems out there.)
 316
 317           If you enable this option then you'll be able to select support
 318           for the following (non-PC) 32 bit x86 platforms:
 319                 AMD Elan
 320                 NUMAQ (IBM/Sequent)
 321                 RDC R-321x SoC
 322                 SGI 320/540 (Visual Workstation)
 323                 Summit/EXA (IBM x440)
 324                 Unisys ES7000 IA32 series
 325                 Moorestown MID devices
 326
 327           If you have one of these systems, or if you want to build a
 328           generic distribution kernel, say Y here - otherwise say N.
 329 endif
 330
 331 if X86_64
 332 config X86_EXTENDED_PLATFORM
 333         bool "Support for extended (non-PC) x86 platforms"
 334         default y
 335         ---help---
 336           If you disable this option then the kernel will only support
 337           standard PC platforms. (which covers the vast majority of
 338           systems out there.)
 339
 340           If you enable this option then you'll be able to select support
 341           for the following (non-PC) 64 bit x86 platforms:
 342                 ScaleMP vSMP
 343                 SGI Ultraviolet
 344
 345           If you have one of these systems, or if you want to build a
 346           generic distribution kernel, say Y here - otherwise say N.
 347 endif
 348 # This is an alphabetically sorted list of 64 bit extended platforms
 349 # Please maintain the alphabetic order if and when there are additions
 350
 351 config X86_VSMP
 352         bool "ScaleMP vSMP"
 353         select PARAVIRT
 354         depends on X86_64 && PCI
 355         depends on X86_EXTENDED_PLATFORM
 356         ---help---
 357           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 358           supposed to run on these EM64T-based machines.  Only choose this option
 359           if you have one of these machines.
 360
 361 config X86_UV
 362         bool "SGI Ultraviolet"
 363         depends on X86_64
 364         depends on X86_EXTENDED_PLATFORM
 365         depends on NUMA
 366         depends on X86_X2APIC
 367         ---help---
 368           This option is needed in order to support SGI Ultraviolet systems.
 369           If you don't have one of these, you should say N here.
 370
 371 # Following is an alphabetically sorted list of 32 bit extended platforms
 372 # Please maintain the alphabetic order if and when there are additions
 373
 374 config X86_ELAN
 375         bool "AMD Elan"
 376         depends on X86_32
 377         depends on X86_EXTENDED_PLATFORM
 378         ---help---
 379           Select this for an AMD Elan processor.
 380
 381           Do not use this option for K6/Athlon/Opteron processors!
 382
 383           If unsure, choose "PC-compatible" instead.
 384
 385 config X86_MRST
 386        bool "Moorestown MID platform"
 387         depends on X86_32
 388         depends on X86_EXTENDED_PLATFORM
 389         ---help---
 390           Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 391           Internet Device(MID) platform. Moorestown consists of two chips:
 392           Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
 393           Unlike standard x86 PCs, Moorestown does not have many legacy devices
 394           nor standard legacy replacement devices/features. e.g. Moorestown does
 395           not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
 396
 397 config X86_RDC321X
 398         bool "RDC R-321x SoC"
 399         depends on X86_32
 400         depends on X86_EXTENDED_PLATFORM
 401         select M486
 402         select X86_REBOOTFIXUPS
 403         ---help---
 404           This option is needed for RDC R-321x system-on-chip, also known
 405           as R-8610-(G).
 406           If you don't have one of these chips, you should say N here.
 407
 408 config X86_32_NON_STANDARD
 409         bool "Support non-standard 32-bit SMP architectures"
 410         depends on X86_32 && SMP
 411         depends on X86_EXTENDED_PLATFORM
 412         ---help---
 413           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 414           subarchitectures.  It is intended for a generic binary kernel.
 415           if you select them all, kernel will probe it one by one. and will
 416           fallback to default.
 417
 418 # Alphabetically sorted list of Non standard 32 bit platforms
 419
 420 config X86_NUMAQ
 421         bool "NUMAQ (IBM/Sequent)"
 422         depends on X86_32_NON_STANDARD
 423         select NUMA
 424         select X86_MPPARSE
 425         ---help---
 426           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 427           NUMA multiquad box. This changes the way that processors are
 428           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 429           of Flat Logical.  You will need a new lynxer.elf file to flash your
 430           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 431
 432 config X86_SUPPORTS_MEMORY_FAILURE
 433         bool
 434         # MCE code calls memory_failure():
 435         depends on X86_MCE
 436         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
 437         depends on !X86_NUMAQ
 438         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
 439         depends on X86_64 || !SPARSEMEM
 440         select ARCH_SUPPORTS_MEMORY_FAILURE
 441         default y
 442
 443 config X86_VISWS
 444         bool "SGI 320/540 (Visual Workstation)"
 445         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 446         depends on X86_32_NON_STANDARD
 447         ---help---
 448           The SGI Visual Workstation series is an IA32-based workstation
 449           based on SGI systems chips with some legacy PC hardware attached.
 450
 451           Say Y here to create a kernel to run on the SGI 320 or 540.
 452
 453           A kernel compiled for the Visual Workstation will run on general
 454           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 455
 456 config X86_SUMMIT
 457         bool "Summit/EXA (IBM x440)"
 458         depends on X86_32_NON_STANDARD
 459         ---help---
 460           This option is needed for IBM systems that use the Summit/EXA chipset.
 461           In particular, it is needed for the x440.
 462
 463 config X86_ES7000
 464         bool "Unisys ES7000 IA32 series"
 465         depends on X86_32_NON_STANDARD && X86_BIGSMP
 466         ---help---
 467           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 468           supposed to run on an IA32-based Unisys ES7000 system.
 469
 470 config SCHED_OMIT_FRAME_POINTER
 471         def_bool y
 472         prompt "Single-depth WCHAN output"
 473         depends on X86
 474         ---help---
 475           Calculate simpler /proc/<PID>/wchan values. If this option
 476           is disabled then wchan values will recurse back to the
 477           caller function. This provides more accurate wchan values,
 478           at the expense of slightly more scheduling overhead.
 479
 480           If in doubt, say "Y".
 481
 482 menuconfig PARAVIRT_GUEST
 483         bool "Paravirtualized guest support"
 484         ---help---
 485           Say Y here to get to see options related to running Linux under
 486           various hypervisors.  This option alone does not add any kernel code.
 487
 488           If you say N, all options in this submenu will be skipped and disabled.
 489
 490 if PARAVIRT_GUEST
 491
 492 source "arch/x86/xen/Kconfig"
 493
 494 config VMI
 495         bool "VMI Guest support (DEPRECATED)"
 496         select PARAVIRT
 497         depends on X86_32
 498         ---help---
 499           VMI provides a paravirtualized interface to the VMware ESX server
 500           (it could be used by other hypervisors in theory too, but is not
 501           at the moment), by linking the kernel to a GPL-ed ROM module
 502           provided by the hypervisor.
 503
 504           As of September 2009, VMware has started a phased retirement
 505           of this feature from VMware's products. Please see
 506           feature-removal-schedule.txt for details.  If you are
 507           planning to enable this option, please note that you cannot
 508           live migrate a VMI enabled VM to a future VMware product,
 509           which doesn't support VMI. So if you expect your kernel to
 510           seamlessly migrate to newer VMware products, keep this
 511           disabled.
 512
 513 config KVM_CLOCK
 514         bool "KVM paravirtualized clock"
 515         select PARAVIRT
 516         select PARAVIRT_CLOCK
 517         ---help---
 518           Turning on this option will allow you to run a paravirtualized clock
 519           when running over the KVM hypervisor. Instead of relying on a PIT
 520           (or probably other) emulation by the underlying device model, the host
 521           provides the guest with timing infrastructure such as time of day, and
 522           system time
 523
 524 config KVM_GUEST
 525         bool "KVM Guest support"
 526         select PARAVIRT
 527         ---help---
 528           This option enables various optimizations for running under the KVM
 529           hypervisor.
 530
 531 source "arch/x86/lguest/Kconfig"
 532
 533 config PARAVIRT
 534         bool "Enable paravirtualization code"
 535         ---help---
 536           This changes the kernel so it can modify itself when it is run
 537           under a hypervisor, potentially improving performance significantly
 538           over full virtualization.  However, when run without a hypervisor
 539           the kernel is theoretically slower and slightly larger.
 540
 541 config PARAVIRT_SPINLOCKS
 542         bool "Paravirtualization layer for spinlocks"
 543         depends on PARAVIRT && SMP && EXPERIMENTAL
 544         ---help---
 545           Paravirtualized spinlocks allow a pvops backend to replace the
 546           spinlock implementation with something virtualization-friendly
 547           (for example, block the virtual CPU rather than spinning).
 548
 549           Unfortunately the downside is an up to 5% performance hit on
 550           native kernels, with various workloads.
 551
 552           If you are unsure how to answer this question, answer N.
 553
 554 config PARAVIRT_CLOCK
 555         bool
 556         default n
 557
 558 endif
 559
 560 config PARAVIRT_DEBUG
 561         bool "paravirt-ops debugging"
 562         depends on PARAVIRT && DEBUG_KERNEL
 563         ---help---
 564           Enable to debug paravirt_ops internals.  Specifically, BUG if
 565           a paravirt_op is missing when it is called.
 566
 567 config MEMTEST
 568         bool "Memtest"
 569         ---help---
 570           This option adds a kernel parameter 'memtest', which allows memtest
 571           to be set.
 572                 memtest=0, mean disabled; -- default
 573                 memtest=1, mean do 1 test pattern;
 574                 ...
 575                 memtest=4, mean do 4 test patterns.
 576           If you are unsure how to answer this question, answer N.
 577
 578 config X86_SUMMIT_NUMA
 579         def_bool y
 580         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 581
 582 config X86_CYCLONE_TIMER
 583         def_bool y
 584         depends on X86_32_NON_STANDARD
 585
 586 source "arch/x86/Kconfig.cpu"
 587
 588 config HPET_TIMER
 589         def_bool X86_64
 590         prompt "HPET Timer Support" if X86_32
 591         ---help---
 592           Use the IA-PC HPET (High Precision Event Timer) to manage
 593           time in preference to the PIT and RTC, if a HPET is
 594           present.
 595           HPET is the next generation timer replacing legacy 8254s.
 596           The HPET provides a stable time base on SMP
 597           systems, unlike the TSC, but it is more expensive to access,
 598           as it is off-chip.  You can find the HPET spec at
 599           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 600
 601           You can safely choose Y here.  However, HPET will only be
 602           activated if the platform and the BIOS support this feature.
 603           Otherwise the 8254 will be used for timing services.
 604
 605           Choose N to continue using the legacy 8254 timer.
 606
 607 config HPET_EMULATE_RTC
 608         def_bool y
 609         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 610
 611 # Mark as embedded because too many people got it wrong.
 612 # The code disables itself when not needed.
 613 config DMI
 614         default y
 615         bool "Enable DMI scanning" if EMBEDDED
 616         ---help---
 617           Enabled scanning of DMI to identify machine quirks. Say Y
 618           here unless you have verified that your setup is not
 619           affected by entries in the DMI blacklist. Required by PNP
 620           BIOS code.
 621
 622 config GART_IOMMU
 623         bool "GART IOMMU support" if EMBEDDED
 624         default y
 625         select SWIOTLB
 626         depends on X86_64 && PCI
 627         ---help---
 628           Support for full DMA access of devices with 32bit memory access only
 629           on systems with more than 3GB. This is usually needed for USB,
 630           sound, many IDE/SATA chipsets and some other devices.
 631           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 632           based hardware IOMMU and a software bounce buffer based IOMMU used
 633           on Intel systems and as fallback.
 634           The code is only active when needed (enough memory and limited
 635           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 636           too.
 637
 638 config CALGARY_IOMMU
 639         bool "IBM Calgary IOMMU support"
 640         select SWIOTLB
 641         depends on X86_64 && PCI && EXPERIMENTAL
 642         ---help---
 643           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 644           systems. Needed to run systems with more than 3GB of memory
 645           properly with 32-bit PCI devices that do not support DAC
 646           (Double Address Cycle). Calgary also supports bus level
 647           isolation, where all DMAs pass through the IOMMU.  This
 648           prevents them from going anywhere except their intended
 649           destination. This catches hard-to-find kernel bugs and
 650           mis-behaving drivers and devices that do not use the DMA-API
 651           properly to set up their DMA buffers.  The IOMMU can be
 652           turned off at boot time with the iommu=off parameter.
 653           Normally the kernel will make the right choice by itself.
 654           If unsure, say Y.
 655
 656 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 657         def_bool y
 658         prompt "Should Calgary be enabled by default?"
 659         depends on CALGARY_IOMMU
 660         ---help---
 661           Should Calgary be enabled by default? if you choose 'y', Calgary
 662           will be used (if it exists). If you choose 'n', Calgary will not be
 663           used even if it exists. If you choose 'n' and would like to use
 664           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 665           If unsure, say Y.
 666
 667 config AMD_IOMMU
 668         bool "AMD IOMMU support"
 669         select SWIOTLB
 670         select PCI_MSI
 671         depends on X86_64 && PCI && ACPI
 672         ---help---
 673           With this option you can enable support for AMD IOMMU hardware in
 674           your system. An IOMMU is a hardware component which provides
 675           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 676           can isolate the the DMA memory of different devices and protect the
 677           system from misbehaving device drivers or hardware.
 678
 679           You can find out if your system has an AMD IOMMU if you look into
 680           your BIOS for an option to enable it or if you have an IVRS ACPI
 681           table.
 682
 683 config AMD_IOMMU_STATS
 684         bool "Export AMD IOMMU statistics to debugfs"
 685         depends on AMD_IOMMU
 686         select DEBUG_FS
 687         ---help---
 688           This option enables code in the AMD IOMMU driver to collect various
 689           statistics about whats happening in the driver and exports that
 690           information to userspace via debugfs.
 691           If unsure, say N.
 692
 693 # need this always selected by IOMMU for the VIA workaround
 694 config SWIOTLB
 695         def_bool y if X86_64
 696         ---help---
 697           Support for software bounce buffers used on x86-64 systems
 698           which don't have a hardware IOMMU (e.g. the current generation
 699           of Intel's x86-64 CPUs). Using this PCI devices which can only
 700           access 32-bits of memory can be used on systems with more than
 701           3 GB of memory. If unsure, say Y.
 702
 703 config IOMMU_HELPER
 704         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 705
 706 config IOMMU_API
 707         def_bool (AMD_IOMMU || DMAR)
 708
 709 config MAXSMP
 710         bool "Configure Maximum number of SMP Processors and NUMA Nodes"
 711         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 712         select CPUMASK_OFFSTACK
 713         default n
 714         ---help---
 715           Configure maximum number of CPUS and NUMA Nodes for this architecture.
 716           If unsure, say N.
 717
 718 config NR_CPUS
 719         int "Maximum number of CPUs" if SMP && !MAXSMP
 720         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 721         range 2 512 if SMP && !MAXSMP
 722         default "1" if !SMP
 723         default "4096" if MAXSMP
 724         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 725         default "8" if SMP
 726         ---help---
 727           This allows you to specify the maximum number of CPUs which this
 728           kernel will support.  The maximum supported value is 512 and the
 729           minimum value which makes sense is 2.
 730
 731           This is purely to save memory - each supported CPU adds
 732           approximately eight kilobytes to the kernel image.
 733
 734 config SCHED_SMT
 735         bool "SMT (Hyperthreading) scheduler support"
 736         depends on X86_HT
 737         ---help---
 738           SMT scheduler support improves the CPU scheduler's decision making
 739           when dealing with Intel Pentium 4 chips with HyperThreading at a
 740           cost of slightly increased overhead in some places. If unsure say
 741           N here.
 742
 743 config SCHED_MC
 744         def_bool y
 745         prompt "Multi-core scheduler support"
 746         depends on X86_HT
 747         ---help---
 748           Multi-core scheduler support improves the CPU scheduler's decision
 749           making when dealing with multi-core CPU chips at a cost of slightly
 750           increased overhead in some places. If unsure say N here.
 751
 752 source "kernel/Kconfig.preempt"
 753
 754 config X86_UP_APIC
 755         bool "Local APIC support on uniprocessors"
 756         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 757         ---help---
 758           A local APIC (Advanced Programmable Interrupt Controller) is an
 759           integrated interrupt controller in the CPU. If you have a single-CPU
 760           system which has a processor with a local APIC, you can say Y here to
 761           enable and use it. If you say Y here even though your machine doesn't
 762           have a local APIC, then the kernel will still run with no slowdown at
 763           all. The local APIC supports CPU-generated self-interrupts (timer,
 764           performance counters), and the NMI watchdog which detects hard
 765           lockups.
 766
 767 config X86_UP_IOAPIC
 768         bool "IO-APIC support on uniprocessors"
 769         depends on X86_UP_APIC
 770         ---help---
 771           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 772           SMP-capable replacement for PC-style interrupt controllers. Most
 773           SMP systems and many recent uniprocessor systems have one.
 774
 775           If you have a single-CPU system with an IO-APIC, you can say Y here
 776           to use it. If you say Y here even though your machine doesn't have
 777           an IO-APIC, then the kernel will still run with no slowdown at all.
 778
 779 config X86_LOCAL_APIC
 780         def_bool y
 781         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 782
 783 config X86_IO_APIC
 784         def_bool y
 785         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 786
 787 config X86_VISWS_APIC
 788         def_bool y
 789         depends on X86_32 && X86_VISWS
 790
 791 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 792         bool "Reroute for broken boot IRQs"
 793         default n
 794         depends on X86_IO_APIC
 795         ---help---
 796           This option enables a workaround that fixes a source of
 797           spurious interrupts. This is recommended when threaded
 798           interrupt handling is used on systems where the generation of
 799           superfluous "boot interrupts" cannot be disabled.
 800
 801           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 802           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 803           kernel does during interrupt handling). On chipsets where this
 804           boot IRQ generation cannot be disabled, this workaround keeps
 805           the original IRQ line masked so that only the equivalent "boot
 806           IRQ" is delivered to the CPUs. The workaround also tells the
 807           kernel to set up the IRQ handler on the boot IRQ line. In this
 808           way only one interrupt is delivered to the kernel. Otherwise
 809           the spurious second interrupt may cause the kernel to bring
 810           down (vital) interrupt lines.
 811
 812           Only affects "broken" chipsets. Interrupt sharing may be
 813           increased on these systems.
 814
 815 config X86_MCE
 816         bool "Machine Check / overheating reporting"
 817         ---help---
 818           Machine Check support allows the processor to notify the
 819           kernel if it detects a problem (e.g. overheating, data corruption).
 820           The action the kernel takes depends on the severity of the problem,
 821           ranging from warning messages to halting the machine.
 822
 823 config X86_MCE_INTEL
 824         def_bool y
 825         prompt "Intel MCE features"
 826         depends on X86_MCE && X86_LOCAL_APIC
 827         ---help---
 828            Additional support for intel specific MCE features such as
 829            the thermal monitor.
 830
 831 config X86_MCE_AMD
 832         def_bool y
 833         prompt "AMD MCE features"
 834         depends on X86_MCE && X86_LOCAL_APIC
 835         ---help---
 836            Additional support for AMD specific MCE features such as
 837            the DRAM Error Threshold.
 838
 839 config X86_ANCIENT_MCE
 840         def_bool n
 841         depends on X86_32 && X86_MCE
 842         prompt "Support for old Pentium 5 / WinChip machine checks"
 843         ---help---
 844           Include support for machine check handling on old Pentium 5 or WinChip
 845           systems. These typically need to be enabled explicitely on the command
 846           line.
 847
 848 config X86_MCE_THRESHOLD
 849         depends on X86_MCE_AMD || X86_MCE_INTEL
 850         bool
 851         default y
 852
 853 config X86_MCE_INJECT
 854         depends on X86_MCE
 855         tristate "Machine check injector support"
 856         ---help---
 857           Provide support for injecting machine checks for testing purposes.
 858           If you don't know what a machine check is and you don't do kernel
 859           QA it is safe to say n.
 860
 861 config X86_THERMAL_VECTOR
 862         def_bool y
 863         depends on X86_MCE_INTEL
 864
 865 config VM86
 866         bool "Enable VM86 support" if EMBEDDED
 867         default y
 868         depends on X86_32
 869         ---help---
 870           This option is required by programs like DOSEMU to run 16-bit legacy
 871           code on X86 processors. It also may be needed by software like
 872           XFree86 to initialize some video cards via BIOS. Disabling this
 873           option saves about 6k.
 874
 875 config TOSHIBA
 876         tristate "Toshiba Laptop support"
 877         depends on X86_32
 878         ---help---
 879           This adds a driver to safely access the System Management Mode of
 880           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 881           not work on models with a Phoenix BIOS. The System Management Mode
 882           is used to set the BIOS and power saving options on Toshiba portables.
 883
 884           For information on utilities to make use of this driver see the
 885           Toshiba Linux utilities web site at:
 886           <http://www.buzzard.org.uk/toshiba/>.
 887
 888           Say Y if you intend to run this kernel on a Toshiba portable.
 889           Say N otherwise.
 890
 891 config I8K
 892         tristate "Dell laptop support"
 893         ---help---
 894           This adds a driver to safely access the System Management Mode
 895           of the CPU on the Dell Inspiron 8000. The System Management Mode
 896           is used to read cpu temperature and cooling fan status and to
 897           control the fans on the I8K portables.
 898
 899           This driver has been tested only on the Inspiron 8000 but it may
 900           also work with other Dell laptops. You can force loading on other
 901           models by passing the parameter `force=1' to the module. Use at
 902           your own risk.
 903
 904           For information on utilities to make use of this driver see the
 905           I8K Linux utilities web site at:
 906           <http://people.debian.org/~dz/i8k/>
 907
 908           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 909           Say N otherwise.
 910
 911 config X86_REBOOTFIXUPS
 912         bool "Enable X86 board specific fixups for reboot"
 913         depends on X86_32
 914         ---help---
 915           This enables chipset and/or board specific fixups to be done
 916           in order to get reboot to work correctly. This is only needed on
 917           some combinations of hardware and BIOS. The symptom, for which
 918           this config is intended, is when reboot ends with a stalled/hung
 919           system.
 920
 921           Currently, the only fixup is for the Geode machines using
 922           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 923
 924           Say Y if you want to enable the fixup. Currently, it's safe to
 925           enable this option even if you don't need it.
 926           Say N otherwise.
 927
 928 config MICROCODE
 929         tristate "/dev/cpu/microcode - microcode support"
 930         select FW_LOADER
 931         ---help---
 932           If you say Y here, you will be able to update the microcode on
 933           certain Intel and AMD processors. The Intel support is for the
 934           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 935           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 936           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 937           You will obviously need the actual microcode binary data itself
 938           which is not shipped with the Linux kernel.
 939
 940           This option selects the general module only, you need to select
 941           at least one vendor specific module as well.
 942
 943           To compile this driver as a module, choose M here: the
 944           module will be called microcode.
 945
 946 config MICROCODE_INTEL
 947         bool "Intel microcode patch loading support"
 948         depends on MICROCODE
 949         default MICROCODE
 950         select FW_LOADER
 951         ---help---
 952           This options enables microcode patch loading support for Intel
 953           processors.
 954
 955           For latest news and information on obtaining all the required
 956           Intel ingredients for this driver, check:
 957           <http://www.urbanmyth.org/microcode/>.
 958
 959 config MICROCODE_AMD
 960         bool "AMD microcode patch loading support"
 961         depends on MICROCODE
 962         select FW_LOADER
 963         ---help---
 964           If you select this option, microcode patch loading support for AMD
 965           processors will be enabled.
 966
 967 config MICROCODE_OLD_INTERFACE
 968         def_bool y
 969         depends on MICROCODE
 970
 971 config X86_MSR
 972         tristate "/dev/cpu/*/msr - Model-specific register support"
 973         ---help---
 974           This device gives privileged processes access to the x86
 975           Model-Specific Registers (MSRs).  It is a character device with
 976           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
 977           MSR accesses are directed to a specific CPU on multi-processor
 978           systems.
 979
 980 config X86_CPUID
 981         tristate "/dev/cpu/*/cpuid - CPU information support"
 982         ---help---
 983           This device gives processes access to the x86 CPUID instruction to
 984           be executed on a specific processor.  It is a character device
 985           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
 986           /dev/cpu/31/cpuid.
 987
 988 config X86_CPU_DEBUG
 989         tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
 990         ---help---
 991           If you select this option, this will provide various x86 CPUs
 992           information through debugfs.
 993
 994 choice
 995         prompt "High Memory Support"
 996         default HIGHMEM4G if !X86_NUMAQ
 997         default HIGHMEM64G if X86_NUMAQ
 998         depends on X86_32
 999
1000 config NOHIGHMEM
1001         bool "off"
1002         depends on !X86_NUMAQ
1003         ---help---
1004           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1005           However, the address space of 32-bit x86 processors is only 4
1006           Gigabytes large. That means that, if you have a large amount of
1007           physical memory, not all of it can be "permanently mapped" by the
1008           kernel. The physical memory that's not permanently mapped is called
1009           "high memory".
1010
1011           If you are compiling a kernel which will never run on a machine with
1012           more than 1 Gigabyte total physical RAM, answer "off" here (default
1013           choice and suitable for most users). This will result in a "3GB/1GB"
1014           split: 3GB are mapped so that each process sees a 3GB virtual memory
1015           space and the remaining part of the 4GB virtual memory space is used
1016           by the kernel to permanently map as much physical memory as
1017           possible.
1018
1019           If the machine has between 1 and 4 Gigabytes physical RAM, then
1020           answer "4GB" here.
1021
1022           If more than 4 Gigabytes is used then answer "64GB" here. This
1023           selection turns Intel PAE (Physical Address Extension) mode on.
1024           PAE implements 3-level paging on IA32 processors. PAE is fully
1025           supported by Linux, PAE mode is implemented on all recent Intel
1026           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1027           then the kernel will not boot on CPUs that don't support PAE!
1028
1029           The actual amount of total physical memory will either be
1030           auto detected or can be forced by using a kernel command line option
1031           such as "mem=256M". (Try "man bootparam" or see the documentation of
1032           your boot loader (lilo or loadlin) about how to pass options to the
1033           kernel at boot time.)
1034
1035           If unsure, say "off".
1036
1037 config HIGHMEM4G
1038         bool "4GB"
1039         depends on !X86_NUMAQ
1040         ---help---
1041           Select this if you have a 32-bit processor and between 1 and 4
1042           gigabytes of physical RAM.
1043
1044 config HIGHMEM64G
1045         bool "64GB"
1046         depends on !M386 && !M486
1047         select X86_PAE
1048         ---help---
1049           Select this if you have a 32-bit processor and more than 4
1050           gigabytes of physical RAM.
1051
1052 endchoice
1053
1054 choice
1055         depends on EXPERIMENTAL
1056         prompt "Memory split" if EMBEDDED
1057         default VMSPLIT_3G
1058         depends on X86_32
1059         ---help---
1060           Select the desired split between kernel and user memory.
1061
1062           If the address range available to the kernel is less than the
1063           physical memory installed, the remaining memory will be available
1064           as "high memory". Accessing high memory is a little more costly
1065           than low memory, as it needs to be mapped into the kernel first.
1066           Note that increasing the kernel address space limits the range
1067           available to user programs, making the address space there
1068           tighter.  Selecting anything other than the default 3G/1G split
1069           will also likely make your kernel incompatible with binary-only
1070           kernel modules.
1071
1072           If you are not absolutely sure what you are doing, leave this
1073           option alone!
1074
1075         config VMSPLIT_3G
1076                 bool "3G/1G user/kernel split"
1077         config VMSPLIT_3G_OPT
1078                 depends on !X86_PAE
1079                 bool "3G/1G user/kernel split (for full 1G low memory)"
1080         config VMSPLIT_2G
1081                 bool "2G/2G user/kernel split"
1082         config VMSPLIT_2G_OPT
1083                 depends on !X86_PAE
1084                 bool "2G/2G user/kernel split (for full 2G low memory)"
1085         config VMSPLIT_1G
1086                 bool "1G/3G user/kernel split"
1087 endchoice
1088
1089 config PAGE_OFFSET
1090         hex
1091         default 0xB0000000 if VMSPLIT_3G_OPT
1092         default 0x80000000 if VMSPLIT_2G
1093         default 0x78000000 if VMSPLIT_2G_OPT
1094         default 0x40000000 if VMSPLIT_1G
1095         default 0xC0000000
1096         depends on X86_32
1097
1098 config HIGHMEM
1099         def_bool y
1100         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1101
1102 config X86_PAE
1103         bool "PAE (Physical Address Extension) Support"
1104         depends on X86_32 && !HIGHMEM4G
1105         ---help---
1106           PAE is required for NX support, and furthermore enables
1107           larger swapspace support for non-overcommit purposes. It
1108           has the cost of more pagetable lookup overhead, and also
1109           consumes more pagetable space per process.
1110
1111 config ARCH_PHYS_ADDR_T_64BIT
1112         def_bool X86_64 || X86_PAE
1113
1114 config DIRECT_GBPAGES
1115         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1116         default y
1117         depends on X86_64
1118         ---help---
1119           Allow the kernel linear mapping to use 1GB pages on CPUs that
1120           support it. This can improve the kernel's performance a tiny bit by
1121           reducing TLB pressure. If in doubt, say "Y".
1122
1123 # Common NUMA Features
1124 config NUMA
1125         bool "Numa Memory Allocation and Scheduler Support"
1126         depends on SMP
1127         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1128         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1129         ---help---
1130           Enable NUMA (Non Uniform Memory Access) support.
1131
1132           The kernel will try to allocate memory used by a CPU on the
1133           local memory controller of the CPU and add some more
1134           NUMA awareness to the kernel.
1135
1136           For 64-bit this is recommended if the system is Intel Core i7
1137           (or later), AMD Opteron, or EM64T NUMA.
1138
1139           For 32-bit this is only needed on (rare) 32-bit-only platforms
1140           that support NUMA topologies, such as NUMAQ / Summit, or if you
1141           boot a 32-bit kernel on a 64-bit NUMA platform.
1142
1143           Otherwise, you should say N.
1144
1145 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1146         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1147
1148 config K8_NUMA
1149         def_bool y
1150         prompt "Old style AMD Opteron NUMA detection"
1151         depends on X86_64 && NUMA && PCI
1152         ---help---
1153           Enable K8 NUMA node topology detection.  You should say Y here if
1154           you have a multi processor AMD K8 system. This uses an old
1155           method to read the NUMA configuration directly from the builtin
1156           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1157           instead, which also takes priority if both are compiled in.
1158
1159 config X86_64_ACPI_NUMA
1160         def_bool y
1161         prompt "ACPI NUMA detection"
1162         depends on X86_64 && NUMA && ACPI && PCI
1163         select ACPI_NUMA
1164         ---help---
1165           Enable ACPI SRAT based node topology detection.
1166
1167 # Some NUMA nodes have memory ranges that span
1168 # other nodes.  Even though a pfn is valid and
1169 # between a node's start and end pfns, it may not
1170 # reside on that node.  See memmap_init_zone()
1171 # for details.
1172 config NODES_SPAN_OTHER_NODES
1173         def_bool y
1174         depends on X86_64_ACPI_NUMA
1175
1176 config NUMA_EMU
1177         bool "NUMA emulation"
1178         depends on X86_64 && NUMA
1179         ---help---
1180           Enable NUMA emulation. A flat machine will be split
1181           into virtual nodes when booted with "numa=fake=N", where N is the
1182           number of nodes. This is only useful for debugging.
1183
1184 config NODES_SHIFT
1185         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1186         range 1 9
1187         default "9" if MAXSMP
1188         default "6" if X86_64
1189         default "4" if X86_NUMAQ
1190         default "3"
1191         depends on NEED_MULTIPLE_NODES
1192         ---help---
1193           Specify the maximum number of NUMA Nodes available on the target
1194           system.  Increases memory reserved to accommodate various tables.
1195
1196 config HAVE_ARCH_BOOTMEM
1197         def_bool y
1198         depends on X86_32 && NUMA
1199
1200 config ARCH_HAVE_MEMORY_PRESENT
1201         def_bool y
1202         depends on X86_32 && DISCONTIGMEM
1203
1204 config NEED_NODE_MEMMAP_SIZE
1205         def_bool y
1206         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1207
1208 config HAVE_ARCH_ALLOC_REMAP
1209         def_bool y
1210         depends on X86_32 && NUMA
1211
1212 config ARCH_FLATMEM_ENABLE
1213         def_bool y
1214         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1215
1216 config ARCH_DISCONTIGMEM_ENABLE
1217         def_bool y
1218         depends on NUMA && X86_32
1219
1220 config ARCH_DISCONTIGMEM_DEFAULT
1221         def_bool y
1222         depends on NUMA && X86_32
1223
1224 config ARCH_PROC_KCORE_TEXT
1225         def_bool y
1226         depends on X86_64 && PROC_KCORE
1227
1228 config ARCH_SPARSEMEM_DEFAULT
1229         def_bool y
1230         depends on X86_64
1231
1232 config ARCH_SPARSEMEM_ENABLE
1233         def_bool y
1234         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1235         select SPARSEMEM_STATIC if X86_32
1236         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1237
1238 config ARCH_SELECT_MEMORY_MODEL
1239         def_bool y
1240         depends on ARCH_SPARSEMEM_ENABLE
1241
1242 config ARCH_MEMORY_PROBE
1243         def_bool X86_64
1244         depends on MEMORY_HOTPLUG
1245
1246 source "mm/Kconfig"
1247
1248 config HIGHPTE
1249         bool "Allocate 3rd-level pagetables from highmem"
1250         depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1251         ---help---
1252           The VM uses one page table entry for each page of physical memory.
1253           For systems with a lot of RAM, this can be wasteful of precious
1254           low memory.  Setting this option will put user-space page table
1255           entries in high memory.
1256
1257 config X86_CHECK_BIOS_CORRUPTION
1258         bool "Check for low memory corruption"
1259         ---help---
1260           Periodically check for memory corruption in low memory, which
1261           is suspected to be caused by BIOS.  Even when enabled in the
1262           configuration, it is disabled at runtime.  Enable it by
1263           setting "memory_corruption_check=1" on the kernel command
1264           line.  By default it scans the low 64k of memory every 60
1265           seconds; see the memory_corruption_check_size and
1266           memory_corruption_check_period parameters in
1267           Documentation/kernel-parameters.txt to adjust this.
1268
1269           When enabled with the default parameters, this option has
1270           almost no overhead, as it reserves a relatively small amount
1271           of memory and scans it infrequently.  It both detects corruption
1272           and prevents it from affecting the running system.
1273
1274           It is, however, intended as a diagnostic tool; if repeatable
1275           BIOS-originated corruption always affects the same memory,
1276           you can use memmap= to prevent the kernel from using that
1277           memory.
1278
1279 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1280         bool "Set the default setting of memory_corruption_check"
1281         depends on X86_CHECK_BIOS_CORRUPTION
1282         default y
1283         ---help---
1284           Set whether the default state of memory_corruption_check is
1285           on or off.
1286
1287 config X86_RESERVE_LOW_64K
1288         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1289         default y
1290         ---help---
1291           Reserve the first 64K of physical RAM on BIOSes that are known
1292           to potentially corrupt that memory range. A numbers of BIOSes are
1293           known to utilize this area during suspend/resume, so it must not
1294           be used by the kernel.
1295
1296           Set this to N if you are absolutely sure that you trust the BIOS
1297           to get all its memory reservations and usages right.
1298
1299           If you have doubts about the BIOS (e.g. suspend/resume does not
1300           work or there's kernel crashes after certain hardware hotplug
1301           events) and it's not AMI or Phoenix, then you might want to enable
1302           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1303           corruption patterns.
1304
1305           Say Y if unsure.
1306
1307 config MATH_EMULATION
1308         bool
1309         prompt "Math emulation" if X86_32
1310         ---help---
1311           Linux can emulate a math coprocessor (used for floating point
1312           operations) if you don't have one. 486DX and Pentium processors have
1313           a math coprocessor built in, 486SX and 386 do not, unless you added
1314           a 487DX or 387, respectively. (The messages during boot time can
1315           give you some hints here ["man dmesg"].) Everyone needs either a
1316           coprocessor or this emulation.
1317
1318           If you don't have a math coprocessor, you need to say Y here; if you
1319           say Y here even though you have a coprocessor, the coprocessor will
1320           be used nevertheless. (This behavior can be changed with the kernel
1321           command line option "no387", which comes handy if your coprocessor
1322           is broken. Try "man bootparam" or see the documentation of your boot
1323           loader (lilo or loadlin) about how to pass options to the kernel at
1324           boot time.) This means that it is a good idea to say Y here if you
1325           intend to use this kernel on different machines.
1326
1327           More information about the internals of the Linux math coprocessor
1328           emulation can be found in <file:arch/x86/math-emu/README>.
1329
1330           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1331           kernel, it won't hurt.
1332
1333 config MTRR
1334         bool "MTRR (Memory Type Range Register) support"
1335         ---help---
1336           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1337           the Memory Type Range Registers (MTRRs) may be used to control
1338           processor access to memory ranges. This is most useful if you have
1339           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1340           allows bus write transfers to be combined into a larger transfer
1341           before bursting over the PCI/AGP bus. This can increase performance
1342           of image write operations 2.5 times or more. Saying Y here creates a
1343           /proc/mtrr file which may be used to manipulate your processor's
1344           MTRRs. Typically the X server should use this.
1345
1346           This code has a reasonably generic interface so that similar
1347           control registers on other processors can be easily supported
1348           as well:
1349
1350           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1351           Registers (ARRs) which provide a similar functionality to MTRRs. For
1352           these, the ARRs are used to emulate the MTRRs.
1353           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1354           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1355           write-combining. All of these processors are supported by this code
1356           and it makes sense to say Y here if you have one of them.
1357
1358           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1359           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1360           can lead to all sorts of problems, so it's good to say Y here.
1361
1362           You can safely say Y even if your machine doesn't have MTRRs, you'll
1363           just add about 9 KB to your kernel.
1364
1365           See <file:Documentation/x86/mtrr.txt> for more information.
1366
1367 config MTRR_SANITIZER
1368         def_bool y
1369         prompt "MTRR cleanup support"
1370         depends on MTRR
1371         ---help---
1372           Convert MTRR layout from continuous to discrete, so X drivers can
1373           add writeback entries.
1374
1375           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1376           The largest mtrr entry size for a continuous block can be set with
1377           mtrr_chunk_size.
1378
1379           If unsure, say Y.
1380
1381 config MTRR_SANITIZER_ENABLE_DEFAULT
1382         int "MTRR cleanup enable value (0-1)"
1383         range 0 1
1384         default "0"
1385         depends on MTRR_SANITIZER
1386         ---help---
1387           Enable mtrr cleanup default value
1388
1389 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1390         int "MTRR cleanup spare reg num (0-7)"
1391         range 0 7
1392         default "1"
1393         depends on MTRR_SANITIZER
1394         ---help---
1395           mtrr cleanup spare entries default, it can be changed via
1396           mtrr_spare_reg_nr=N on the kernel command line.
1397
1398 config X86_PAT
1399         bool
1400         prompt "x86 PAT support"
1401         depends on MTRR
1402         ---help---
1403           Use PAT attributes to setup page level cache control.
1404
1405           PATs are the modern equivalents of MTRRs and are much more
1406           flexible than MTRRs.
1407
1408           Say N here if you see bootup problems (boot crash, boot hang,
1409           spontaneous reboots) or a non-working video driver.
1410
1411           If unsure, say Y.
1412
1413 config ARCH_USES_PG_UNCACHED
1414         def_bool y
1415         depends on X86_PAT
1416
1417 config EFI
1418         bool "EFI runtime service support"
1419         depends on ACPI
1420         ---help---
1421           This enables the kernel to use EFI runtime services that are
1422           available (such as the EFI variable services).
1423
1424           This option is only useful on systems that have EFI firmware.
1425           In addition, you should use the latest ELILO loader available
1426           at <http://elilo.sourceforge.net> in order to take advantage
1427           of EFI runtime services. However, even with this option, the
1428           resultant kernel should continue to boot on existing non-EFI
1429           platforms.
1430
1431 config SECCOMP
1432         def_bool y
1433         prompt "Enable seccomp to safely compute untrusted bytecode"
1434         ---help---
1435           This kernel feature is useful for number crunching applications
1436           that may need to compute untrusted bytecode during their
1437           execution. By using pipes or other transports made available to
1438           the process as file descriptors supporting the read/write
1439           syscalls, it's possible to isolate those applications in
1440           their own address space using seccomp. Once seccomp is
1441           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1442           and the task is only allowed to execute a few safe syscalls
1443           defined by each seccomp mode.
1444
1445           If unsure, say Y. Only embedded should say N here.
1446
1447 config CC_STACKPROTECTOR_ALL
1448         bool
1449
1450 config CC_STACKPROTECTOR
1451         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1452         select CC_STACKPROTECTOR_ALL
1453         ---help---
1454           This option turns on the -fstack-protector GCC feature. This
1455           feature puts, at the beginning of functions, a canary value on
1456           the stack just before the return address, and validates
1457           the value just before actually returning.  Stack based buffer
1458           overflows (that need to overwrite this return address) now also
1459           overwrite the canary, which gets detected and the attack is then
1460           neutralized via a kernel panic.
1461
1462           This feature requires gcc version 4.2 or above, or a distribution
1463           gcc with the feature backported. Older versions are automatically
1464           detected and for those versions, this configuration option is
1465           ignored. (and a warning is printed during bootup)
1466
1467 source kernel/Kconfig.hz
1468
1469 config KEXEC
1470         bool "kexec system call"
1471         ---help---
1472           kexec is a system call that implements the ability to shutdown your
1473           current kernel, and to start another kernel.  It is like a reboot
1474           but it is independent of the system firmware.   And like a reboot
1475           you can start any kernel with it, not just Linux.
1476
1477           The name comes from the similarity to the exec system call.
1478
1479           It is an ongoing process to be certain the hardware in a machine
1480           is properly shutdown, so do not be surprised if this code does not
1481           initially work for you.  It may help to enable device hotplugging
1482           support.  As of this writing the exact hardware interface is
1483           strongly in flux, so no good recommendation can be made.
1484
1485 config CRASH_DUMP
1486         bool "kernel crash dumps"
1487         depends on X86_64 || (X86_32 && HIGHMEM)
1488         ---help---
1489           Generate crash dump after being started by kexec.
1490           This should be normally only set in special crash dump kernels
1491           which are loaded in the main kernel with kexec-tools into
1492           a specially reserved region and then later executed after
1493           a crash by kdump/kexec. The crash dump kernel must be compiled
1494           to a memory address not used by the main kernel or BIOS using
1495           PHYSICAL_START, or it must be built as a relocatable image
1496           (CONFIG_RELOCATABLE=y).
1497           For more details see Documentation/kdump/kdump.txt
1498
1499 config KEXEC_JUMP
1500         bool "kexec jump (EXPERIMENTAL)"
1501         depends on EXPERIMENTAL
1502         depends on KEXEC && HIBERNATION
1503         ---help---
1504           Jump between original kernel and kexeced kernel and invoke
1505           code in physical address mode via KEXEC
1506
1507 config PHYSICAL_START
1508         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1509         default "0x1000000"
1510         ---help---
1511           This gives the physical address where the kernel is loaded.
1512
1513           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1514           bzImage will decompress itself to above physical address and
1515           run from there. Otherwise, bzImage will run from the address where
1516           it has been loaded by the boot loader and will ignore above physical
1517           address.
1518
1519           In normal kdump cases one does not have to set/change this option
1520           as now bzImage can be compiled as a completely relocatable image
1521           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1522           address. This option is mainly useful for the folks who don't want
1523           to use a bzImage for capturing the crash dump and want to use a
1524           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1525           to be specifically compiled to run from a specific memory area
1526           (normally a reserved region) and this option comes handy.
1527
1528           So if you are using bzImage for capturing the crash dump,
1529           leave the value here unchanged to 0x1000000 and set
1530           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1531           for capturing the crash dump change this value to start of
1532           the reserved region.  In other words, it can be set based on
1533           the "X" value as specified in the "crashkernel=YM@XM"
1534           command line boot parameter passed to the panic-ed
1535           kernel. Please take a look at Documentation/kdump/kdump.txt
1536           for more details about crash dumps.
1537
1538           Usage of bzImage for capturing the crash dump is recommended as
1539           one does not have to build two kernels. Same kernel can be used
1540           as production kernel and capture kernel. Above option should have
1541           gone away after relocatable bzImage support is introduced. But it
1542           is present because there are users out there who continue to use
1543           vmlinux for dump capture. This option should go away down the
1544           line.
1545
1546           Don't change this unless you know what you are doing.
1547
1548 config RELOCATABLE
1549         bool "Build a relocatable kernel"
1550         default y
1551         ---help---
1552           This builds a kernel image that retains relocation information
1553           so it can be loaded someplace besides the default 1MB.
1554           The relocations tend to make the kernel binary about 10% larger,
1555           but are discarded at runtime.
1556
1557           One use is for the kexec on panic case where the recovery kernel
1558           must live at a different physical address than the primary
1559           kernel.
1560
1561           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1562           it has been loaded at and the compile time physical address
1563           (CONFIG_PHYSICAL_START) is ignored.
1564
1565 # Relocation on x86-32 needs some additional build support
1566 config X86_NEED_RELOCS
1567         def_bool y
1568         depends on X86_32 && RELOCATABLE
1569
1570 config PHYSICAL_ALIGN
1571         hex
1572         prompt "Alignment value to which kernel should be aligned" if X86_32
1573         default "0x1000000"
1574         range 0x2000 0x1000000
1575         ---help---
1576           This value puts the alignment restrictions on physical address
1577           where kernel is loaded and run from. Kernel is compiled for an
1578           address which meets above alignment restriction.
1579
1580           If bootloader loads the kernel at a non-aligned address and
1581           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1582           address aligned to above value and run from there.
1583
1584           If bootloader loads the kernel at a non-aligned address and
1585           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1586           load address and decompress itself to the address it has been
1587           compiled for and run from there. The address for which kernel is
1588           compiled already meets above alignment restrictions. Hence the
1589           end result is that kernel runs from a physical address meeting
1590           above alignment restrictions.
1591
1592           Don't change this unless you know what you are doing.
1593
1594 config HOTPLUG_CPU
1595         bool "Support for hot-pluggable CPUs"
1596         depends on SMP && HOTPLUG
1597         ---help---
1598           Say Y here to allow turning CPUs off and on. CPUs can be
1599           controlled through /sys/devices/system/cpu.
1600           ( Note: power management support will enable this option
1601             automatically on SMP systems. )
1602           Say N if you want to disable CPU hotplug.
1603
1604 config COMPAT_VDSO
1605         def_bool y
1606         prompt "Compat VDSO support"
1607         depends on X86_32 || IA32_EMULATION
1608         ---help---
1609           Map the 32-bit VDSO to the predictable old-style address too.
1610         ---help---
1611           Say N here if you are running a sufficiently recent glibc
1612           version (2.3.3 or later), to remove the high-mapped
1613           VDSO mapping and to exclusively use the randomized VDSO.
1614
1615           If unsure, say Y.
1616
1617 config CMDLINE_BOOL
1618         bool "Built-in kernel command line"
1619         default n
1620         ---help---
1621           Allow for specifying boot arguments to the kernel at
1622           build time.  On some systems (e.g. embedded ones), it is
1623           necessary or convenient to provide some or all of the
1624           kernel boot arguments with the kernel itself (that is,
1625           to not rely on the boot loader to provide them.)
1626
1627           To compile command line arguments into the kernel,
1628           set this option to 'Y', then fill in the
1629           the boot arguments in CONFIG_CMDLINE.
1630
1631           Systems with fully functional boot loaders (i.e. non-embedded)
1632           should leave this option set to 'N'.
1633
1634 config CMDLINE
1635         string "Built-in kernel command string"
1636         depends on CMDLINE_BOOL
1637         default ""
1638         ---help---
1639           Enter arguments here that should be compiled into the kernel
1640           image and used at boot time.  If the boot loader provides a
1641           command line at boot time, it is appended to this string to
1642           form the full kernel command line, when the system boots.
1643
1644           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1645           change this behavior.
1646
1647           In most cases, the command line (whether built-in or provided
1648           by the boot loader) should specify the device for the root
1649           file system.
1650
1651 config CMDLINE_OVERRIDE
1652         bool "Built-in command line overrides boot loader arguments"
1653         default n
1654         depends on CMDLINE_BOOL
1655         ---help---
1656           Set this option to 'Y' to have the kernel ignore the boot loader
1657           command line, and use ONLY the built-in command line.
1658
1659           This is used to work around broken boot loaders.  This should
1660           be set to 'N' under normal conditions.
1661
1662 endmenu
1663
1664 config ARCH_ENABLE_MEMORY_HOTPLUG
1665         def_bool y
1666         depends on X86_64 || (X86_32 && HIGHMEM)
1667
1668 config ARCH_ENABLE_MEMORY_HOTREMOVE
1669         def_bool y
1670         depends on MEMORY_HOTPLUG
1671
1672 config HAVE_ARCH_EARLY_PFN_TO_NID
1673         def_bool X86_64
1674         depends on NUMA
1675
1676 menu "Power management and ACPI options"
1677
1678 config ARCH_HIBERNATION_HEADER
1679         def_bool y
1680         depends on X86_64 && HIBERNATION
1681
1682 source "kernel/power/Kconfig"
1683
1684 source "drivers/acpi/Kconfig"
1685
1686 source "drivers/sfi/Kconfig"
1687
1688 config X86_APM_BOOT
1689         bool
1690         default y
1691         depends on APM || APM_MODULE
1692
1693 menuconfig APM
1694         tristate "APM (Advanced Power Management) BIOS support"
1695         depends on X86_32 && PM_SLEEP
1696         ---help---
1697           APM is a BIOS specification for saving power using several different
1698           techniques. This is mostly useful for battery powered laptops with
1699           APM compliant BIOSes. If you say Y here, the system time will be
1700           reset after a RESUME operation, the /proc/apm device will provide
1701           battery status information, and user-space programs will receive
1702           notification of APM "events" (e.g. battery status change).
1703
1704           If you select "Y" here, you can disable actual use of the APM
1705           BIOS by passing the "apm=off" option to the kernel at boot time.
1706
1707           Note that the APM support is almost completely disabled for
1708           machines with more than one CPU.
1709
1710           In order to use APM, you will need supporting software. For location
1711           and more information, read <file:Documentation/power/pm.txt> and the
1712           Battery Powered Linux mini-HOWTO, available from
1713           <http://www.tldp.org/docs.html#howto>.
1714
1715           This driver does not spin down disk drives (see the hdparm(8)
1716           manpage ("man 8 hdparm") for that), and it doesn't turn off
1717           VESA-compliant "green" monitors.
1718
1719           This driver does not support the TI 4000M TravelMate and the ACER
1720           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1721           desktop machines also don't have compliant BIOSes, and this driver
1722           may cause those machines to panic during the boot phase.
1723
1724           Generally, if you don't have a battery in your machine, there isn't
1725           much point in using this driver and you should say N. If you get
1726           random kernel OOPSes or reboots that don't seem to be related to
1727           anything, try disabling/enabling this option (or disabling/enabling
1728           APM in your BIOS).
1729
1730           Some other things you should try when experiencing seemingly random,
1731           "weird" problems:
1732
1733           1) make sure that you have enough swap space and that it is
1734           enabled.
1735           2) pass the "no-hlt" option to the kernel
1736           3) switch on floating point emulation in the kernel and pass
1737           the "no387" option to the kernel
1738           4) pass the "floppy=nodma" option to the kernel
1739           5) pass the "mem=4M" option to the kernel (thereby disabling
1740           all but the first 4 MB of RAM)
1741           6) make sure that the CPU is not over clocked.
1742           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1743           8) disable the cache from your BIOS settings
1744           9) install a fan for the video card or exchange video RAM
1745           10) install a better fan for the CPU
1746           11) exchange RAM chips
1747           12) exchange the motherboard.
1748
1749           To compile this driver as a module, choose M here: the
1750           module will be called apm.
1751
1752 if APM
1753
1754 config APM_IGNORE_USER_SUSPEND
1755         bool "Ignore USER SUSPEND"
1756         ---help---
1757           This option will ignore USER SUSPEND requests. On machines with a
1758           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1759           series notebooks, it is necessary to say Y because of a BIOS bug.
1760
1761 config APM_DO_ENABLE
1762         bool "Enable PM at boot time"
1763         ---help---
1764           Enable APM features at boot time. From page 36 of the APM BIOS
1765           specification: "When disabled, the APM BIOS does not automatically
1766           power manage devices, enter the Standby State, enter the Suspend
1767           State, or take power saving steps in response to CPU Idle calls."
1768           This driver will make CPU Idle calls when Linux is idle (unless this
1769           feature is turned off -- see "Do CPU IDLE calls", below). This
1770           should always save battery power, but more complicated APM features
1771           will be dependent on your BIOS implementation. You may need to turn
1772           this option off if your computer hangs at boot time when using APM
1773           support, or if it beeps continuously instead of suspending. Turn
1774           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1775           T400CDT. This is off by default since most machines do fine without
1776           this feature.
1777
1778 config APM_CPU_IDLE
1779         bool "Make CPU Idle calls when idle"
1780         ---help---
1781           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1782           On some machines, this can activate improved power savings, such as
1783           a slowed CPU clock rate, when the machine is idle. These idle calls
1784           are made after the idle loop has run for some length of time (e.g.,
1785           333 mS). On some machines, this will cause a hang at boot time or
1786           whenever the CPU becomes idle. (On machines with more than one CPU,
1787           this option does nothing.)
1788
1789 config APM_DISPLAY_BLANK
1790         bool "Enable console blanking using APM"
1791         ---help---
1792           Enable console blanking using the APM. Some laptops can use this to
1793           turn off the LCD backlight when the screen blanker of the Linux
1794           virtual console blanks the screen. Note that this is only used by
1795           the virtual console screen blanker, and won't turn off the backlight
1796           when using the X Window system. This also doesn't have anything to
1797           do with your VESA-compliant power-saving monitor. Further, this
1798           option doesn't work for all laptops -- it might not turn off your
1799           backlight at all, or it might print a lot of errors to the console,
1800           especially if you are using gpm.
1801
1802 config APM_ALLOW_INTS
1803         bool "Allow interrupts during APM BIOS calls"
1804         ---help---
1805           Normally we disable external interrupts while we are making calls to
1806           the APM BIOS as a measure to lessen the effects of a badly behaving
1807           BIOS implementation.  The BIOS should reenable interrupts if it
1808           needs to.  Unfortunately, some BIOSes do not -- especially those in
1809           many of the newer IBM Thinkpads.  If you experience hangs when you
1810           suspend, try setting this to Y.  Otherwise, say N.
1811
1812 endif # APM
1813
1814 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1815
1816 source "drivers/cpuidle/Kconfig"
1817
1818 source "drivers/idle/Kconfig"
1819
1820 endmenu
1821
1822
1823 menu "Bus options (PCI etc.)"
1824
1825 config PCI
1826         bool "PCI support"
1827         default y
1828         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1829         ---help---
1830           Find out whether you have a PCI motherboard. PCI is the name of a
1831           bus system, i.e. the way the CPU talks to the other stuff inside
1832           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1833           VESA. If you have PCI, say Y, otherwise N.
1834
1835 choice
1836         prompt "PCI access mode"
1837         depends on X86_32 && PCI
1838         default PCI_GOANY
1839         ---help---
1840           On PCI systems, the BIOS can be used to detect the PCI devices and
1841           determine their configuration. However, some old PCI motherboards
1842           have BIOS bugs and may crash if this is done. Also, some embedded
1843           PCI-based systems don't have any BIOS at all. Linux can also try to
1844           detect the PCI hardware directly without using the BIOS.
1845
1846           With this option, you can specify how Linux should detect the
1847           PCI devices. If you choose "BIOS", the BIOS will be used,
1848           if you choose "Direct", the BIOS won't be used, and if you
1849           choose "MMConfig", then PCI Express MMCONFIG will be used.
1850           If you choose "Any", the kernel will try MMCONFIG, then the
1851           direct access method and falls back to the BIOS if that doesn't
1852           work. If unsure, go with the default, which is "Any".
1853
1854 config PCI_GOBIOS
1855         bool "BIOS"
1856
1857 config PCI_GOMMCONFIG
1858         bool "MMConfig"
1859
1860 config PCI_GODIRECT
1861         bool "Direct"
1862
1863 config PCI_GOOLPC
1864         bool "OLPC"
1865         depends on OLPC
1866
1867 config PCI_GOANY
1868         bool "Any"
1869
1870 endchoice
1871
1872 config PCI_BIOS
1873         def_bool y
1874         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1875
1876 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1877 config PCI_DIRECT
1878         def_bool y
1879         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1880
1881 config PCI_MMCONFIG
1882         def_bool y
1883         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1884
1885 config PCI_OLPC
1886         def_bool y
1887         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1888
1889 config PCI_DOMAINS
1890         def_bool y
1891         depends on PCI
1892
1893 config PCI_MMCONFIG
1894         bool "Support mmconfig PCI config space access"
1895         depends on X86_64 && PCI && ACPI
1896
1897 config DMAR
1898         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1899         depends on PCI_MSI && ACPI && EXPERIMENTAL
1900         help
1901           DMA remapping (DMAR) devices support enables independent address
1902           translations for Direct Memory Access (DMA) from devices.
1903           These DMA remapping devices are reported via ACPI tables
1904           and include PCI device scope covered by these DMA
1905           remapping devices.
1906
1907 config DMAR_DEFAULT_ON
1908         def_bool y
1909         prompt "Enable DMA Remapping Devices by default"
1910         depends on DMAR
1911         help
1912           Selecting this option will enable a DMAR device at boot time if
1913           one is found. If this option is not selected, DMAR support can
1914           be enabled by passing intel_iommu=on to the kernel. It is
1915           recommended you say N here while the DMAR code remains
1916           experimental.
1917
1918 config DMAR_BROKEN_GFX_WA
1919         def_bool n
1920         prompt "Workaround broken graphics drivers (going away soon)"
1921         depends on DMAR && BROKEN
1922         ---help---
1923           Current Graphics drivers tend to use physical address
1924           for DMA and avoid using DMA APIs. Setting this config
1925           option permits the IOMMU driver to set a unity map for
1926           all the OS-visible memory. Hence the driver can continue
1927           to use physical addresses for DMA, at least until this
1928           option is removed in the 2.6.32 kernel.
1929
1930 config DMAR_FLOPPY_WA
1931         def_bool y
1932         depends on DMAR
1933         ---help---
1934           Floppy disk drivers are known to bypass DMA API calls
1935           thereby failing to work when IOMMU is enabled. This
1936           workaround will setup a 1:1 mapping for the first
1937           16MiB to make floppy (an ISA device) work.
1938
1939 config INTR_REMAP
1940         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1941         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1942         ---help---
1943           Supports Interrupt remapping for IO-APIC and MSI devices.
1944           To use x2apic mode in the CPU's which support x2APIC enhancements or
1945           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1946
1947 source "drivers/pci/pcie/Kconfig"
1948
1949 source "drivers/pci/Kconfig"
1950
1951 # x86_64 have no ISA slots, but do have ISA-style DMA.
1952 config ISA_DMA_API
1953         def_bool y
1954
1955 if X86_32
1956
1957 config ISA
1958         bool "ISA support"
1959         ---help---
1960           Find out whether you have ISA slots on your motherboard.  ISA is the
1961           name of a bus system, i.e. the way the CPU talks to the other stuff
1962           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1963           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1964           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1965
1966 config EISA
1967         bool "EISA support"
1968         depends on ISA
1969         ---help---
1970           The Extended Industry Standard Architecture (EISA) bus was
1971           developed as an open alternative to the IBM MicroChannel bus.
1972
1973           The EISA bus provided some of the features of the IBM MicroChannel
1974           bus while maintaining backward compatibility with cards made for
1975           the older ISA bus.  The EISA bus saw limited use between 1988 and
1976           1995 when it was made obsolete by the PCI bus.
1977
1978           Say Y here if you are building a kernel for an EISA-based machine.
1979
1980           Otherwise, say N.
1981
1982 source "drivers/eisa/Kconfig"
1983
1984 config MCA
1985         bool "MCA support"
1986         ---help---
1987           MicroChannel Architecture is found in some IBM PS/2 machines and
1988           laptops.  It is a bus system similar to PCI or ISA. See
1989           <file:Documentation/mca.txt> (and especially the web page given
1990           there) before attempting to build an MCA bus kernel.
1991
1992 source "drivers/mca/Kconfig"
1993
1994 config SCx200
1995         tristate "NatSemi SCx200 support"
1996         ---help---
1997           This provides basic support for National Semiconductor's
1998           (now AMD's) Geode processors.  The driver probes for the
1999           PCI-IDs of several on-chip devices, so its a good dependency
2000           for other scx200_* drivers.
2001
2002           If compiled as a module, the driver is named scx200.
2003
2004 config SCx200HR_TIMER
2005         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2006         depends on SCx200 && GENERIC_TIME
2007         default y
2008         ---help---
2009           This driver provides a clocksource built upon the on-chip
2010           27MHz high-resolution timer.  Its also a workaround for
2011           NSC Geode SC-1100's buggy TSC, which loses time when the
2012           processor goes idle (as is done by the scheduler).  The
2013           other workaround is idle=poll boot option.
2014
2015 config GEODE_MFGPT_TIMER
2016         def_bool y
2017         prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2018         depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2019         ---help---
2020           This driver provides a clock event source based on the MFGPT
2021           timer(s) in the CS5535 and CS5536 companion chip for the geode.
2022           MFGPTs have a better resolution and max interval than the
2023           generic PIT, and are suitable for use as high-res timers.
2024
2025 config OLPC
2026         bool "One Laptop Per Child support"
2027         default n
2028         ---help---
2029           Add support for detecting the unique features of the OLPC
2030           XO hardware.
2031
2032 endif # X86_32
2033
2034 config K8_NB
2035         def_bool y
2036         depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2037
2038 source "drivers/pcmcia/Kconfig"
2039
2040 source "drivers/pci/hotplug/Kconfig"
2041
2042 endmenu
2043
2044
2045 menu "Executable file formats / Emulations"
2046
2047 source "fs/Kconfig.binfmt"
2048
2049 config IA32_EMULATION
2050         bool "IA32 Emulation"
2051         depends on X86_64
2052         select COMPAT_BINFMT_ELF
2053         ---help---
2054           Include code to run 32-bit programs under a 64-bit kernel. You should
2055           likely turn this on, unless you're 100% sure that you don't have any
2056           32-bit programs left.
2057
2058 config IA32_AOUT
2059         tristate "IA32 a.out support"
2060         depends on IA32_EMULATION
2061         ---help---
2062           Support old a.out binaries in the 32bit emulation.
2063
2064 config COMPAT
2065         def_bool y
2066         depends on IA32_EMULATION
2067
2068 config COMPAT_FOR_U64_ALIGNMENT
2069         def_bool COMPAT
2070         depends on X86_64
2071
2072 config SYSVIPC_COMPAT
2073         def_bool y
2074         depends on COMPAT && SYSVIPC
2075
2076 endmenu
2077
2078
2079 config HAVE_ATOMIC_IOMAP
2080         def_bool y
2081         depends on X86_32
2082
2083 source "net/Kconfig"
2084
2085 source "drivers/Kconfig"
2086
2087 source "drivers/firmware/Kconfig"
2088
2089 source "fs/Kconfig"
2090
2091 source "arch/x86/Kconfig.debug"
2092
2093 source "security/Kconfig"
2094
2095 source "crypto/Kconfig"
2096
2097 source "arch/x86/kvm/Kconfig"
2098
2099 source "lib/Kconfig"