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_KERNEL_LZO
  53         select HAVE_HW_BREAKPOINT
  54         select PERF_EVENTS
  55         select ANON_INODES
  56         select HAVE_ARCH_KMEMCHECK
  57         select HAVE_USER_RETURN_NOTIFIER
  58
  59 config OUTPUT_FORMAT
  60         string
  61         default "elf32-i386" if X86_32
  62         default "elf64-x86-64" if X86_64
  63
  64 config ARCH_DEFCONFIG
  65         string
  66         default "arch/x86/configs/i386_defconfig" if X86_32
  67         default "arch/x86/configs/x86_64_defconfig" if X86_64
  68
  69 config GENERIC_TIME
  70         def_bool y
  71
  72 config GENERIC_CMOS_UPDATE
  73         def_bool y
  74
  75 config CLOCKSOURCE_WATCHDOG
  76         def_bool y
  77
  78 config GENERIC_CLOCKEVENTS
  79         def_bool y
  80
  81 config GENERIC_CLOCKEVENTS_BROADCAST
  82         def_bool y
  83         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  84
  85 config LOCKDEP_SUPPORT
  86         def_bool y
  87
  88 config STACKTRACE_SUPPORT
  89         def_bool y
  90
  91 config HAVE_LATENCYTOP_SUPPORT
  92         def_bool y
  93
  94 config MMU
  95         def_bool y
  96
  97 config ZONE_DMA
  98         def_bool y
  99
 100 config SBUS
 101         bool
 102
 103 config GENERIC_ISA_DMA
 104         def_bool y
 105
 106 config GENERIC_IOMAP
 107         def_bool y
 108
 109 config GENERIC_BUG
 110         def_bool y
 111         depends on BUG
 112         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 113
 114 config GENERIC_BUG_RELATIVE_POINTERS
 115         bool
 116
 117 config GENERIC_HWEIGHT
 118         def_bool y
 119
 120 config GENERIC_GPIO
 121         bool
 122
 123 config ARCH_MAY_HAVE_PC_FDC
 124         def_bool y
 125
 126 config RWSEM_GENERIC_SPINLOCK
 127         def_bool !X86_XADD
 128
 129 config RWSEM_XCHGADD_ALGORITHM
 130         def_bool X86_XADD
 131
 132 config ARCH_HAS_CPU_IDLE_WAIT
 133         def_bool y
 134
 135 config GENERIC_CALIBRATE_DELAY
 136         def_bool y
 137
 138 config GENERIC_TIME_VSYSCALL
 139         bool
 140         default X86_64
 141
 142 config ARCH_HAS_CPU_RELAX
 143         def_bool y
 144
 145 config ARCH_HAS_DEFAULT_IDLE
 146         def_bool y
 147
 148 config ARCH_HAS_CACHE_LINE_SIZE
 149         def_bool y
 150
 151 config HAVE_SETUP_PER_CPU_AREA
 152         def_bool y
 153
 154 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 155         def_bool y
 156
 157 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 158         def_bool y
 159
 160 config HAVE_CPUMASK_OF_CPU_MAP
 161         def_bool X86_64_SMP
 162
 163 config ARCH_HIBERNATION_POSSIBLE
 164         def_bool y
 165
 166 config ARCH_SUSPEND_POSSIBLE
 167         def_bool y
 168
 169 config ZONE_DMA32
 170         bool
 171         default X86_64
 172
 173 config ARCH_POPULATES_NODE_MAP
 174         def_bool y
 175
 176 config AUDIT_ARCH
 177         bool
 178         default X86_64
 179
 180 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 181         def_bool y
 182
 183 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 184         def_bool y
 185
 186 config HAVE_INTEL_TXT
 187         def_bool y
 188         depends on EXPERIMENTAL && DMAR && ACPI
 189
 190 # Use the generic interrupt handling code in kernel/irq/:
 191 config GENERIC_HARDIRQS
 192         bool
 193         default y
 194
 195 config GENERIC_HARDIRQS_NO__DO_IRQ
 196        def_bool y
 197
 198 config GENERIC_IRQ_PROBE
 199         bool
 200         default y
 201
 202 config GENERIC_PENDING_IRQ
 203         bool
 204         depends on GENERIC_HARDIRQS && SMP
 205         default y
 206
 207 config USE_GENERIC_SMP_HELPERS
 208         def_bool y
 209         depends on SMP
 210
 211 config X86_32_SMP
 212         def_bool y
 213         depends on X86_32 && SMP
 214
 215 config X86_64_SMP
 216         def_bool y
 217         depends on X86_64 && SMP
 218
 219 config X86_HT
 220         bool
 221         depends on SMP
 222         default y
 223
 224 config X86_TRAMPOLINE
 225         bool
 226         depends on SMP || (64BIT && ACPI_SLEEP)
 227         default y
 228
 229 config X86_32_LAZY_GS
 230         def_bool y
 231         depends on X86_32 && !CC_STACKPROTECTOR
 232
 233 config KTIME_SCALAR
 234         def_bool X86_32
 235 source "init/Kconfig"
 236 source "kernel/Kconfig.freezer"
 237
 238 menu "Processor type and features"
 239
 240 source "kernel/time/Kconfig"
 241
 242 config SMP
 243         bool "Symmetric multi-processing support"
 244         ---help---
 245           This enables support for systems with more than one CPU. If you have
 246           a system with only one CPU, like most personal computers, say N. If
 247           you have a system with more than one CPU, say Y.
 248
 249           If you say N here, the kernel will run on single and multiprocessor
 250           machines, but will use only one CPU of a multiprocessor machine. If
 251           you say Y here, the kernel will run on many, but not all,
 252           singleprocessor machines. On a singleprocessor machine, the kernel
 253           will run faster if you say N here.
 254
 255           Note that if you say Y here and choose architecture "586" or
 256           "Pentium" under "Processor family", the kernel will not work on 486
 257           architectures. Similarly, multiprocessor kernels for the "PPro"
 258           architecture may not work on all Pentium based boards.
 259
 260           People using multiprocessor machines who say Y here should also say
 261           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 262           Management" code will be disabled if you say Y here.
 263
 264           See also <file:Documentation/i386/IO-APIC.txt>,
 265           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 266           <http://www.tldp.org/docs.html#howto>.
 267
 268           If you don't know what to do here, say N.
 269
 270 config X86_X2APIC
 271         bool "Support x2apic"
 272         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 273         ---help---
 274           This enables x2apic support on CPUs that have this feature.
 275
 276           This allows 32-bit apic IDs (so it can support very large systems),
 277           and accesses the local apic via MSRs not via mmio.
 278
 279           If you don't know what to do here, say N.
 280
 281 config SPARSE_IRQ
 282         bool "Support sparse irq numbering"
 283         depends on PCI_MSI || HT_IRQ
 284         ---help---
 285           This enables support for sparse irqs. This is useful for distro
 286           kernels that want to define a high CONFIG_NR_CPUS value but still
 287           want to have low kernel memory footprint on smaller machines.
 288
 289           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 290             out the irq_desc[] array in a more NUMA-friendly way. )
 291
 292           If you don't know what to do here, say N.
 293
 294 config NUMA_IRQ_DESC
 295         def_bool y
 296         depends on SPARSE_IRQ && NUMA
 297
 298 config X86_MPPARSE
 299         bool "Enable MPS table" if ACPI
 300         default y
 301         depends on X86_LOCAL_APIC
 302         ---help---
 303           For old smp systems that do not have proper acpi support. Newer systems
 304           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 305
 306 config X86_BIGSMP
 307         bool "Support for big SMP systems with more than 8 CPUs"
 308         depends on X86_32 && SMP
 309         ---help---
 310           This option is needed for the systems that have more than 8 CPUs
 311
 312 if X86_32
 313 config X86_EXTENDED_PLATFORM
 314         bool "Support for extended (non-PC) x86 platforms"
 315         default y
 316         ---help---
 317           If you disable this option then the kernel will only support
 318           standard PC platforms. (which covers the vast majority of
 319           systems out there.)
 320
 321           If you enable this option then you'll be able to select support
 322           for the following (non-PC) 32 bit x86 platforms:
 323                 AMD Elan
 324                 NUMAQ (IBM/Sequent)
 325                 RDC R-321x SoC
 326                 SGI 320/540 (Visual Workstation)
 327                 Summit/EXA (IBM x440)
 328                 Unisys ES7000 IA32 series
 329                 Moorestown MID devices
 330
 331           If you have one of these systems, or if you want to build a
 332           generic distribution kernel, say Y here - otherwise say N.
 333 endif
 334
 335 if X86_64
 336 config X86_EXTENDED_PLATFORM
 337         bool "Support for extended (non-PC) x86 platforms"
 338         default y
 339         ---help---
 340           If you disable this option then the kernel will only support
 341           standard PC platforms. (which covers the vast majority of
 342           systems out there.)
 343
 344           If you enable this option then you'll be able to select support
 345           for the following (non-PC) 64 bit x86 platforms:
 346                 ScaleMP vSMP
 347                 SGI Ultraviolet
 348
 349           If you have one of these systems, or if you want to build a
 350           generic distribution kernel, say Y here - otherwise say N.
 351 endif
 352 # This is an alphabetically sorted list of 64 bit extended platforms
 353 # Please maintain the alphabetic order if and when there are additions
 354
 355 config X86_VSMP
 356         bool "ScaleMP vSMP"
 357         select PARAVIRT
 358         depends on X86_64 && PCI
 359         depends on X86_EXTENDED_PLATFORM
 360         ---help---
 361           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 362           supposed to run on these EM64T-based machines.  Only choose this option
 363           if you have one of these machines.
 364
 365 config X86_UV
 366         bool "SGI Ultraviolet"
 367         depends on X86_64
 368         depends on X86_EXTENDED_PLATFORM
 369         depends on NUMA
 370         depends on X86_X2APIC
 371         ---help---
 372           This option is needed in order to support SGI Ultraviolet systems.
 373           If you don't have one of these, you should say N here.
 374
 375 # Following is an alphabetically sorted list of 32 bit extended platforms
 376 # Please maintain the alphabetic order if and when there are additions
 377
 378 config X86_ELAN
 379         bool "AMD Elan"
 380         depends on X86_32
 381         depends on X86_EXTENDED_PLATFORM
 382         ---help---
 383           Select this for an AMD Elan processor.
 384
 385           Do not use this option for K6/Athlon/Opteron processors!
 386
 387           If unsure, choose "PC-compatible" instead.
 388
 389 config X86_MRST
 390        bool "Moorestown MID platform"
 391         depends on X86_32
 392         depends on X86_EXTENDED_PLATFORM
 393         ---help---
 394           Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 395           Internet Device(MID) platform. Moorestown consists of two chips:
 396           Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
 397           Unlike standard x86 PCs, Moorestown does not have many legacy devices
 398           nor standard legacy replacement devices/features. e.g. Moorestown does
 399           not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
 400
 401 config X86_RDC321X
 402         bool "RDC R-321x SoC"
 403         depends on X86_32
 404         depends on X86_EXTENDED_PLATFORM
 405         select M486
 406         select X86_REBOOTFIXUPS
 407         ---help---
 408           This option is needed for RDC R-321x system-on-chip, also known
 409           as R-8610-(G).
 410           If you don't have one of these chips, you should say N here.
 411
 412 config X86_32_NON_STANDARD
 413         bool "Support non-standard 32-bit SMP architectures"
 414         depends on X86_32 && SMP
 415         depends on X86_EXTENDED_PLATFORM
 416         ---help---
 417           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 418           subarchitectures.  It is intended for a generic binary kernel.
 419           if you select them all, kernel will probe it one by one. and will
 420           fallback to default.
 421
 422 # Alphabetically sorted list of Non standard 32 bit platforms
 423
 424 config X86_NUMAQ
 425         bool "NUMAQ (IBM/Sequent)"
 426         depends on X86_32_NON_STANDARD
 427         select NUMA
 428         select X86_MPPARSE
 429         ---help---
 430           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 431           NUMA multiquad box. This changes the way that processors are
 432           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 433           of Flat Logical.  You will need a new lynxer.elf file to flash your
 434           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 435
 436 config X86_SUPPORTS_MEMORY_FAILURE
 437         bool
 438         # MCE code calls memory_failure():
 439         depends on X86_MCE
 440         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
 441         depends on !X86_NUMAQ
 442         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
 443         depends on X86_64 || !SPARSEMEM
 444         select ARCH_SUPPORTS_MEMORY_FAILURE
 445         default y
 446
 447 config X86_VISWS
 448         bool "SGI 320/540 (Visual Workstation)"
 449         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 450         depends on X86_32_NON_STANDARD
 451         ---help---
 452           The SGI Visual Workstation series is an IA32-based workstation
 453           based on SGI systems chips with some legacy PC hardware attached.
 454
 455           Say Y here to create a kernel to run on the SGI 320 or 540.
 456
 457           A kernel compiled for the Visual Workstation will run on general
 458           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 459
 460 config X86_SUMMIT
 461         bool "Summit/EXA (IBM x440)"
 462         depends on X86_32_NON_STANDARD
 463         ---help---
 464           This option is needed for IBM systems that use the Summit/EXA chipset.
 465           In particular, it is needed for the x440.
 466
 467 config X86_ES7000
 468         bool "Unisys ES7000 IA32 series"
 469         depends on X86_32_NON_STANDARD && X86_BIGSMP
 470         ---help---
 471           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 472           supposed to run on an IA32-based Unisys ES7000 system.
 473
 474 config SCHED_OMIT_FRAME_POINTER
 475         def_bool y
 476         prompt "Single-depth WCHAN output"
 477         depends on X86
 478         ---help---
 479           Calculate simpler /proc/<PID>/wchan values. If this option
 480           is disabled then wchan values will recurse back to the
 481           caller function. This provides more accurate wchan values,
 482           at the expense of slightly more scheduling overhead.
 483
 484           If in doubt, say "Y".
 485
 486 menuconfig PARAVIRT_GUEST
 487         bool "Paravirtualized guest support"
 488         ---help---
 489           Say Y here to get to see options related to running Linux under
 490           various hypervisors.  This option alone does not add any kernel code.
 491
 492           If you say N, all options in this submenu will be skipped and disabled.
 493
 494 if PARAVIRT_GUEST
 495
 496 source "arch/x86/xen/Kconfig"
 497
 498 config VMI
 499         bool "VMI Guest support (DEPRECATED)"
 500         select PARAVIRT
 501         depends on X86_32
 502         ---help---
 503           VMI provides a paravirtualized interface to the VMware ESX server
 504           (it could be used by other hypervisors in theory too, but is not
 505           at the moment), by linking the kernel to a GPL-ed ROM module
 506           provided by the hypervisor.
 507
 508           As of September 2009, VMware has started a phased retirement
 509           of this feature from VMware's products. Please see
 510           feature-removal-schedule.txt for details.  If you are
 511           planning to enable this option, please note that you cannot
 512           live migrate a VMI enabled VM to a future VMware product,
 513           which doesn't support VMI. So if you expect your kernel to
 514           seamlessly migrate to newer VMware products, keep this
 515           disabled.
 516
 517 config KVM_CLOCK
 518         bool "KVM paravirtualized clock"
 519         select PARAVIRT
 520         select PARAVIRT_CLOCK
 521         ---help---
 522           Turning on this option will allow you to run a paravirtualized clock
 523           when running over the KVM hypervisor. Instead of relying on a PIT
 524           (or probably other) emulation by the underlying device model, the host
 525           provides the guest with timing infrastructure such as time of day, and
 526           system time
 527
 528 config KVM_GUEST
 529         bool "KVM Guest support"
 530         select PARAVIRT
 531         ---help---
 532           This option enables various optimizations for running under the KVM
 533           hypervisor.
 534
 535 source "arch/x86/lguest/Kconfig"
 536
 537 config PARAVIRT
 538         bool "Enable paravirtualization code"
 539         ---help---
 540           This changes the kernel so it can modify itself when it is run
 541           under a hypervisor, potentially improving performance significantly
 542           over full virtualization.  However, when run without a hypervisor
 543           the kernel is theoretically slower and slightly larger.
 544
 545 config PARAVIRT_SPINLOCKS
 546         bool "Paravirtualization layer for spinlocks"
 547         depends on PARAVIRT && SMP && EXPERIMENTAL
 548         ---help---
 549           Paravirtualized spinlocks allow a pvops backend to replace the
 550           spinlock implementation with something virtualization-friendly
 551           (for example, block the virtual CPU rather than spinning).
 552
 553           Unfortunately the downside is an up to 5% performance hit on
 554           native kernels, with various workloads.
 555
 556           If you are unsure how to answer this question, answer N.
 557
 558 config PARAVIRT_CLOCK
 559         bool
 560         default n
 561
 562 endif
 563
 564 config PARAVIRT_DEBUG
 565         bool "paravirt-ops debugging"
 566         depends on PARAVIRT && DEBUG_KERNEL
 567         ---help---
 568           Enable to debug paravirt_ops internals.  Specifically, BUG if
 569           a paravirt_op is missing when it is called.
 570
 571 config MEMTEST
 572         bool "Memtest"
 573         ---help---
 574           This option adds a kernel parameter 'memtest', which allows memtest
 575           to be set.
 576                 memtest=0, mean disabled; -- default
 577                 memtest=1, mean do 1 test pattern;
 578                 ...
 579                 memtest=4, mean do 4 test patterns.
 580           If you are unsure how to answer this question, answer N.
 581
 582 config X86_SUMMIT_NUMA
 583         def_bool y
 584         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 585
 586 config X86_CYCLONE_TIMER
 587         def_bool y
 588         depends on X86_32_NON_STANDARD
 589
 590 source "arch/x86/Kconfig.cpu"
 591
 592 config HPET_TIMER
 593         def_bool X86_64
 594         prompt "HPET Timer Support" if X86_32
 595         ---help---
 596           Use the IA-PC HPET (High Precision Event Timer) to manage
 597           time in preference to the PIT and RTC, if a HPET is
 598           present.
 599           HPET is the next generation timer replacing legacy 8254s.
 600           The HPET provides a stable time base on SMP
 601           systems, unlike the TSC, but it is more expensive to access,
 602           as it is off-chip.  You can find the HPET spec at
 603           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 604
 605           You can safely choose Y here.  However, HPET will only be
 606           activated if the platform and the BIOS support this feature.
 607           Otherwise the 8254 will be used for timing services.
 608
 609           Choose N to continue using the legacy 8254 timer.
 610
 611 config HPET_EMULATE_RTC
 612         def_bool y
 613         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 614
 615 # Mark as embedded because too many people got it wrong.
 616 # The code disables itself when not needed.
 617 config DMI
 618         default y
 619         bool "Enable DMI scanning" if EMBEDDED
 620         ---help---
 621           Enabled scanning of DMI to identify machine quirks. Say Y
 622           here unless you have verified that your setup is not
 623           affected by entries in the DMI blacklist. Required by PNP
 624           BIOS code.
 625
 626 config GART_IOMMU
 627         bool "GART IOMMU support" if EMBEDDED
 628         default y
 629         select SWIOTLB
 630         depends on X86_64 && PCI
 631         ---help---
 632           Support for full DMA access of devices with 32bit memory access only
 633           on systems with more than 3GB. This is usually needed for USB,
 634           sound, many IDE/SATA chipsets and some other devices.
 635           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 636           based hardware IOMMU and a software bounce buffer based IOMMU used
 637           on Intel systems and as fallback.
 638           The code is only active when needed (enough memory and limited
 639           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 640           too.
 641
 642 config CALGARY_IOMMU
 643         bool "IBM Calgary IOMMU support"
 644         select SWIOTLB
 645         depends on X86_64 && PCI && EXPERIMENTAL
 646         ---help---
 647           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 648           systems. Needed to run systems with more than 3GB of memory
 649           properly with 32-bit PCI devices that do not support DAC
 650           (Double Address Cycle). Calgary also supports bus level
 651           isolation, where all DMAs pass through the IOMMU.  This
 652           prevents them from going anywhere except their intended
 653           destination. This catches hard-to-find kernel bugs and
 654           mis-behaving drivers and devices that do not use the DMA-API
 655           properly to set up their DMA buffers.  The IOMMU can be
 656           turned off at boot time with the iommu=off parameter.
 657           Normally the kernel will make the right choice by itself.
 658           If unsure, say Y.
 659
 660 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 661         def_bool y
 662         prompt "Should Calgary be enabled by default?"
 663         depends on CALGARY_IOMMU
 664         ---help---
 665           Should Calgary be enabled by default? if you choose 'y', Calgary
 666           will be used (if it exists). If you choose 'n', Calgary will not be
 667           used even if it exists. If you choose 'n' and would like to use
 668           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 669           If unsure, say Y.
 670
 671 config AMD_IOMMU
 672         bool "AMD IOMMU support"
 673         select SWIOTLB
 674         select PCI_MSI
 675         depends on X86_64 && PCI && ACPI
 676         ---help---
 677           With this option you can enable support for AMD IOMMU hardware in
 678           your system. An IOMMU is a hardware component which provides
 679           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 680           can isolate the the DMA memory of different devices and protect the
 681           system from misbehaving device drivers or hardware.
 682
 683           You can find out if your system has an AMD IOMMU if you look into
 684           your BIOS for an option to enable it or if you have an IVRS ACPI
 685           table.
 686
 687 config AMD_IOMMU_STATS
 688         bool "Export AMD IOMMU statistics to debugfs"
 689         depends on AMD_IOMMU
 690         select DEBUG_FS
 691         ---help---
 692           This option enables code in the AMD IOMMU driver to collect various
 693           statistics about whats happening in the driver and exports that
 694           information to userspace via debugfs.
 695           If unsure, say N.
 696
 697 # need this always selected by IOMMU for the VIA workaround
 698 config SWIOTLB
 699         def_bool y if X86_64
 700         ---help---
 701           Support for software bounce buffers used on x86-64 systems
 702           which don't have a hardware IOMMU (e.g. the current generation
 703           of Intel's x86-64 CPUs). Using this PCI devices which can only
 704           access 32-bits of memory can be used on systems with more than
 705           3 GB of memory. If unsure, say Y.
 706
 707 config IOMMU_HELPER
 708         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 709
 710 config IOMMU_API
 711         def_bool (AMD_IOMMU || DMAR)
 712
 713 config MAXSMP
 714         bool "Configure Maximum number of SMP Processors and NUMA Nodes"
 715         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 716         select CPUMASK_OFFSTACK
 717         default n
 718         ---help---
 719           Configure maximum number of CPUS and NUMA Nodes for this architecture.
 720           If unsure, say N.
 721
 722 config NR_CPUS
 723         int "Maximum number of CPUs" if SMP && !MAXSMP
 724         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 725         range 2 512 if SMP && !MAXSMP
 726         default "1" if !SMP
 727         default "4096" if MAXSMP
 728         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 729         default "8" if SMP
 730         ---help---
 731           This allows you to specify the maximum number of CPUs which this
 732           kernel will support.  The maximum supported value is 512 and the
 733           minimum value which makes sense is 2.
 734
 735           This is purely to save memory - each supported CPU adds
 736           approximately eight kilobytes to the kernel image.
 737
 738 config SCHED_SMT
 739         bool "SMT (Hyperthreading) scheduler support"
 740         depends on X86_HT
 741         ---help---
 742           SMT scheduler support improves the CPU scheduler's decision making
 743           when dealing with Intel Pentium 4 chips with HyperThreading at a
 744           cost of slightly increased overhead in some places. If unsure say
 745           N here.
 746
 747 config SCHED_MC
 748         def_bool y
 749         prompt "Multi-core scheduler support"
 750         depends on X86_HT
 751         ---help---
 752           Multi-core scheduler support improves the CPU scheduler's decision
 753           making when dealing with multi-core CPU chips at a cost of slightly
 754           increased overhead in some places. If unsure say N here.
 755
 756 source "kernel/Kconfig.preempt"
 757
 758 config X86_UP_APIC
 759         bool "Local APIC support on uniprocessors"
 760         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 761         ---help---
 762           A local APIC (Advanced Programmable Interrupt Controller) is an
 763           integrated interrupt controller in the CPU. If you have a single-CPU
 764           system which has a processor with a local APIC, you can say Y here to
 765           enable and use it. If you say Y here even though your machine doesn't
 766           have a local APIC, then the kernel will still run with no slowdown at
 767           all. The local APIC supports CPU-generated self-interrupts (timer,
 768           performance counters), and the NMI watchdog which detects hard
 769           lockups.
 770
 771 config X86_UP_IOAPIC
 772         bool "IO-APIC support on uniprocessors"
 773         depends on X86_UP_APIC
 774         ---help---
 775           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 776           SMP-capable replacement for PC-style interrupt controllers. Most
 777           SMP systems and many recent uniprocessor systems have one.
 778
 779           If you have a single-CPU system with an IO-APIC, you can say Y here
 780           to use it. If you say Y here even though your machine doesn't have
 781           an IO-APIC, then the kernel will still run with no slowdown at all.
 782
 783 config X86_LOCAL_APIC
 784         def_bool y
 785         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 786
 787 config X86_IO_APIC
 788         def_bool y
 789         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 790
 791 config X86_VISWS_APIC
 792         def_bool y
 793         depends on X86_32 && X86_VISWS
 794
 795 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 796         bool "Reroute for broken boot IRQs"
 797         default n
 798         depends on X86_IO_APIC
 799         ---help---
 800           This option enables a workaround that fixes a source of
 801           spurious interrupts. This is recommended when threaded
 802           interrupt handling is used on systems where the generation of
 803           superfluous "boot interrupts" cannot be disabled.
 804
 805           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 806           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 807           kernel does during interrupt handling). On chipsets where this
 808           boot IRQ generation cannot be disabled, this workaround keeps
 809           the original IRQ line masked so that only the equivalent "boot
 810           IRQ" is delivered to the CPUs. The workaround also tells the
 811           kernel to set up the IRQ handler on the boot IRQ line. In this
 812           way only one interrupt is delivered to the kernel. Otherwise
 813           the spurious second interrupt may cause the kernel to bring
 814           down (vital) interrupt lines.
 815
 816           Only affects "broken" chipsets. Interrupt sharing may be
 817           increased on these systems.
 818
 819 config X86_MCE
 820         bool "Machine Check / overheating reporting"
 821         ---help---
 822           Machine Check support allows the processor to notify the
 823           kernel if it detects a problem (e.g. overheating, data corruption).
 824           The action the kernel takes depends on the severity of the problem,
 825           ranging from warning messages to halting the machine.
 826
 827 config X86_MCE_INTEL
 828         def_bool y
 829         prompt "Intel MCE features"
 830         depends on X86_MCE && X86_LOCAL_APIC
 831         ---help---
 832            Additional support for intel specific MCE features such as
 833            the thermal monitor.
 834
 835 config X86_MCE_AMD
 836         def_bool y
 837         prompt "AMD MCE features"
 838         depends on X86_MCE && X86_LOCAL_APIC
 839         ---help---
 840            Additional support for AMD specific MCE features such as
 841            the DRAM Error Threshold.
 842
 843 config X86_ANCIENT_MCE
 844         def_bool n
 845         depends on X86_32 && X86_MCE
 846         prompt "Support for old Pentium 5 / WinChip machine checks"
 847         ---help---
 848           Include support for machine check handling on old Pentium 5 or WinChip
 849           systems. These typically need to be enabled explicitely on the command
 850           line.
 851
 852 config X86_MCE_THRESHOLD
 853         depends on X86_MCE_AMD || X86_MCE_INTEL
 854         bool
 855         default y
 856
 857 config X86_MCE_INJECT
 858         depends on X86_MCE
 859         tristate "Machine check injector support"
 860         ---help---
 861           Provide support for injecting machine checks for testing purposes.
 862           If you don't know what a machine check is and you don't do kernel
 863           QA it is safe to say n.
 864
 865 config X86_THERMAL_VECTOR
 866         def_bool y
 867         depends on X86_MCE_INTEL
 868
 869 config VM86
 870         bool "Enable VM86 support" if EMBEDDED
 871         default y
 872         depends on X86_32
 873         ---help---
 874           This option is required by programs like DOSEMU to run 16-bit legacy
 875           code on X86 processors. It also may be needed by software like
 876           XFree86 to initialize some video cards via BIOS. Disabling this
 877           option saves about 6k.
 878
 879 config TOSHIBA
 880         tristate "Toshiba Laptop support"
 881         depends on X86_32
 882         ---help---
 883           This adds a driver to safely access the System Management Mode of
 884           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 885           not work on models with a Phoenix BIOS. The System Management Mode
 886           is used to set the BIOS and power saving options on Toshiba portables.
 887
 888           For information on utilities to make use of this driver see the
 889           Toshiba Linux utilities web site at:
 890           <http://www.buzzard.org.uk/toshiba/>.
 891
 892           Say Y if you intend to run this kernel on a Toshiba portable.
 893           Say N otherwise.
 894
 895 config I8K
 896         tristate "Dell laptop support"
 897         ---help---
 898           This adds a driver to safely access the System Management Mode
 899           of the CPU on the Dell Inspiron 8000. The System Management Mode
 900           is used to read cpu temperature and cooling fan status and to
 901           control the fans on the I8K portables.
 902
 903           This driver has been tested only on the Inspiron 8000 but it may
 904           also work with other Dell laptops. You can force loading on other
 905           models by passing the parameter `force=1' to the module. Use at
 906           your own risk.
 907
 908           For information on utilities to make use of this driver see the
 909           I8K Linux utilities web site at:
 910           <http://people.debian.org/~dz/i8k/>
 911
 912           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 913           Say N otherwise.
 914
 915 config X86_REBOOTFIXUPS
 916         bool "Enable X86 board specific fixups for reboot"
 917         depends on X86_32
 918         ---help---
 919           This enables chipset and/or board specific fixups to be done
 920           in order to get reboot to work correctly. This is only needed on
 921           some combinations of hardware and BIOS. The symptom, for which
 922           this config is intended, is when reboot ends with a stalled/hung
 923           system.
 924
 925           Currently, the only fixup is for the Geode machines using
 926           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 927
 928           Say Y if you want to enable the fixup. Currently, it's safe to
 929           enable this option even if you don't need it.
 930           Say N otherwise.
 931
 932 config MICROCODE
 933         tristate "/dev/cpu/microcode - microcode support"
 934         select FW_LOADER
 935         ---help---
 936           If you say Y here, you will be able to update the microcode on
 937           certain Intel and AMD processors. The Intel support is for the
 938           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 939           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 940           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 941           You will obviously need the actual microcode binary data itself
 942           which is not shipped with the Linux kernel.
 943
 944           This option selects the general module only, you need to select
 945           at least one vendor specific module as well.
 946
 947           To compile this driver as a module, choose M here: the
 948           module will be called microcode.
 949
 950 config MICROCODE_INTEL
 951         bool "Intel microcode patch loading support"
 952         depends on MICROCODE
 953         default MICROCODE
 954         select FW_LOADER
 955         ---help---
 956           This options enables microcode patch loading support for Intel
 957           processors.
 958
 959           For latest news and information on obtaining all the required
 960           Intel ingredients for this driver, check:
 961           <http://www.urbanmyth.org/microcode/>.
 962
 963 config MICROCODE_AMD
 964         bool "AMD microcode patch loading support"
 965         depends on MICROCODE
 966         select FW_LOADER
 967         ---help---
 968           If you select this option, microcode patch loading support for AMD
 969           processors will be enabled.
 970
 971 config MICROCODE_OLD_INTERFACE
 972         def_bool y
 973         depends on MICROCODE
 974
 975 config X86_MSR
 976         tristate "/dev/cpu/*/msr - Model-specific register support"
 977         ---help---
 978           This device gives privileged processes access to the x86
 979           Model-Specific Registers (MSRs).  It is a character device with
 980           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
 981           MSR accesses are directed to a specific CPU on multi-processor
 982           systems.
 983
 984 config X86_CPUID
 985         tristate "/dev/cpu/*/cpuid - CPU information support"
 986         ---help---
 987           This device gives processes access to the x86 CPUID instruction to
 988           be executed on a specific processor.  It is a character device
 989           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
 990           /dev/cpu/31/cpuid.
 991
 992 choice
 993         prompt "High Memory Support"
 994         default HIGHMEM4G if !X86_NUMAQ
 995         default HIGHMEM64G if X86_NUMAQ
 996         depends on X86_32
 997
 998 config NOHIGHMEM
 999         bool "off"
1000         depends on !X86_NUMAQ
1001         ---help---
1002           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1003           However, the address space of 32-bit x86 processors is only 4
1004           Gigabytes large. That means that, if you have a large amount of
1005           physical memory, not all of it can be "permanently mapped" by the
1006           kernel. The physical memory that's not permanently mapped is called
1007           "high memory".
1008
1009           If you are compiling a kernel which will never run on a machine with
1010           more than 1 Gigabyte total physical RAM, answer "off" here (default
1011           choice and suitable for most users). This will result in a "3GB/1GB"
1012           split: 3GB are mapped so that each process sees a 3GB virtual memory
1013           space and the remaining part of the 4GB virtual memory space is used
1014           by the kernel to permanently map as much physical memory as
1015           possible.
1016
1017           If the machine has between 1 and 4 Gigabytes physical RAM, then
1018           answer "4GB" here.
1019
1020           If more than 4 Gigabytes is used then answer "64GB" here. This
1021           selection turns Intel PAE (Physical Address Extension) mode on.
1022           PAE implements 3-level paging on IA32 processors. PAE is fully
1023           supported by Linux, PAE mode is implemented on all recent Intel
1024           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1025           then the kernel will not boot on CPUs that don't support PAE!
1026
1027           The actual amount of total physical memory will either be
1028           auto detected or can be forced by using a kernel command line option
1029           such as "mem=256M". (Try "man bootparam" or see the documentation of
1030           your boot loader (lilo or loadlin) about how to pass options to the
1031           kernel at boot time.)
1032
1033           If unsure, say "off".
1034
1035 config HIGHMEM4G
1036         bool "4GB"
1037         depends on !X86_NUMAQ
1038         ---help---
1039           Select this if you have a 32-bit processor and between 1 and 4
1040           gigabytes of physical RAM.
1041
1042 config HIGHMEM64G
1043         bool "64GB"
1044         depends on !M386 && !M486
1045         select X86_PAE
1046         ---help---
1047           Select this if you have a 32-bit processor and more than 4
1048           gigabytes of physical RAM.
1049
1050 endchoice
1051
1052 choice
1053         depends on EXPERIMENTAL
1054         prompt "Memory split" if EMBEDDED
1055         default VMSPLIT_3G
1056         depends on X86_32
1057         ---help---
1058           Select the desired split between kernel and user memory.
1059
1060           If the address range available to the kernel is less than the
1061           physical memory installed, the remaining memory will be available
1062           as "high memory". Accessing high memory is a little more costly
1063           than low memory, as it needs to be mapped into the kernel first.
1064           Note that increasing the kernel address space limits the range
1065           available to user programs, making the address space there
1066           tighter.  Selecting anything other than the default 3G/1G split
1067           will also likely make your kernel incompatible with binary-only
1068           kernel modules.
1069
1070           If you are not absolutely sure what you are doing, leave this
1071           option alone!
1072
1073         config VMSPLIT_3G
1074                 bool "3G/1G user/kernel split"
1075         config VMSPLIT_3G_OPT
1076                 depends on !X86_PAE
1077                 bool "3G/1G user/kernel split (for full 1G low memory)"
1078         config VMSPLIT_2G
1079                 bool "2G/2G user/kernel split"
1080         config VMSPLIT_2G_OPT
1081                 depends on !X86_PAE
1082                 bool "2G/2G user/kernel split (for full 2G low memory)"
1083         config VMSPLIT_1G
1084                 bool "1G/3G user/kernel split"
1085 endchoice
1086
1087 config PAGE_OFFSET
1088         hex
1089         default 0xB0000000 if VMSPLIT_3G_OPT
1090         default 0x80000000 if VMSPLIT_2G
1091         default 0x78000000 if VMSPLIT_2G_OPT
1092         default 0x40000000 if VMSPLIT_1G
1093         default 0xC0000000
1094         depends on X86_32
1095
1096 config HIGHMEM
1097         def_bool y
1098         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1099
1100 config X86_PAE
1101         bool "PAE (Physical Address Extension) Support"
1102         depends on X86_32 && !HIGHMEM4G
1103         ---help---
1104           PAE is required for NX support, and furthermore enables
1105           larger swapspace support for non-overcommit purposes. It
1106           has the cost of more pagetable lookup overhead, and also
1107           consumes more pagetable space per process.
1108
1109 config ARCH_PHYS_ADDR_T_64BIT
1110         def_bool X86_64 || X86_PAE
1111
1112 config DIRECT_GBPAGES
1113         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1114         default y
1115         depends on X86_64
1116         ---help---
1117           Allow the kernel linear mapping to use 1GB pages on CPUs that
1118           support it. This can improve the kernel's performance a tiny bit by
1119           reducing TLB pressure. If in doubt, say "Y".
1120
1121 # Common NUMA Features
1122 config NUMA
1123         bool "Numa Memory Allocation and Scheduler Support"
1124         depends on SMP
1125         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1126         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1127         ---help---
1128           Enable NUMA (Non Uniform Memory Access) support.
1129
1130           The kernel will try to allocate memory used by a CPU on the
1131           local memory controller of the CPU and add some more
1132           NUMA awareness to the kernel.
1133
1134           For 64-bit this is recommended if the system is Intel Core i7
1135           (or later), AMD Opteron, or EM64T NUMA.
1136
1137           For 32-bit this is only needed on (rare) 32-bit-only platforms
1138           that support NUMA topologies, such as NUMAQ / Summit, or if you
1139           boot a 32-bit kernel on a 64-bit NUMA platform.
1140
1141           Otherwise, you should say N.
1142
1143 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1144         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1145
1146 config K8_NUMA
1147         def_bool y
1148         prompt "Old style AMD Opteron NUMA detection"
1149         depends on X86_64 && NUMA && PCI
1150         ---help---
1151           Enable K8 NUMA node topology detection.  You should say Y here if
1152           you have a multi processor AMD K8 system. This uses an old
1153           method to read the NUMA configuration directly from the builtin
1154           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1155           instead, which also takes priority if both are compiled in.
1156
1157 config X86_64_ACPI_NUMA
1158         def_bool y
1159         prompt "ACPI NUMA detection"
1160         depends on X86_64 && NUMA && ACPI && PCI
1161         select ACPI_NUMA
1162         ---help---
1163           Enable ACPI SRAT based node topology detection.
1164
1165 # Some NUMA nodes have memory ranges that span
1166 # other nodes.  Even though a pfn is valid and
1167 # between a node's start and end pfns, it may not
1168 # reside on that node.  See memmap_init_zone()
1169 # for details.
1170 config NODES_SPAN_OTHER_NODES
1171         def_bool y
1172         depends on X86_64_ACPI_NUMA
1173
1174 config NUMA_EMU
1175         bool "NUMA emulation"
1176         depends on X86_64 && NUMA
1177         ---help---
1178           Enable NUMA emulation. A flat machine will be split
1179           into virtual nodes when booted with "numa=fake=N", where N is the
1180           number of nodes. This is only useful for debugging.
1181
1182 config NODES_SHIFT
1183         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1184         range 1 9
1185         default "9" if MAXSMP
1186         default "6" if X86_64
1187         default "4" if X86_NUMAQ
1188         default "3"
1189         depends on NEED_MULTIPLE_NODES
1190         ---help---
1191           Specify the maximum number of NUMA Nodes available on the target
1192           system.  Increases memory reserved to accommodate various tables.
1193
1194 config HAVE_ARCH_BOOTMEM
1195         def_bool y
1196         depends on X86_32 && NUMA
1197
1198 config ARCH_HAVE_MEMORY_PRESENT
1199         def_bool y
1200         depends on X86_32 && DISCONTIGMEM
1201
1202 config NEED_NODE_MEMMAP_SIZE
1203         def_bool y
1204         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1205
1206 config HAVE_ARCH_ALLOC_REMAP
1207         def_bool y
1208         depends on X86_32 && NUMA
1209
1210 config ARCH_FLATMEM_ENABLE
1211         def_bool y
1212         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1213
1214 config ARCH_DISCONTIGMEM_ENABLE
1215         def_bool y
1216         depends on NUMA && X86_32
1217
1218 config ARCH_DISCONTIGMEM_DEFAULT
1219         def_bool y
1220         depends on NUMA && X86_32
1221
1222 config ARCH_PROC_KCORE_TEXT
1223         def_bool y
1224         depends on X86_64 && PROC_KCORE
1225
1226 config ARCH_SPARSEMEM_DEFAULT
1227         def_bool y
1228         depends on X86_64
1229
1230 config ARCH_SPARSEMEM_ENABLE
1231         def_bool y
1232         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1233         select SPARSEMEM_STATIC if X86_32
1234         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1235
1236 config ARCH_SELECT_MEMORY_MODEL
1237         def_bool y
1238         depends on ARCH_SPARSEMEM_ENABLE
1239
1240 config ARCH_MEMORY_PROBE
1241         def_bool X86_64
1242         depends on MEMORY_HOTPLUG
1243
1244 config ILLEGAL_POINTER_VALUE
1245        hex
1246        default 0 if X86_32
1247        default 0xdead000000000000 if X86_64
1248
1249 source "mm/Kconfig"
1250
1251 config HIGHPTE
1252         bool "Allocate 3rd-level pagetables from highmem"
1253         depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1254         ---help---
1255           The VM uses one page table entry for each page of physical memory.
1256           For systems with a lot of RAM, this can be wasteful of precious
1257           low memory.  Setting this option will put user-space page table
1258           entries in high memory.
1259
1260 config X86_CHECK_BIOS_CORRUPTION
1261         bool "Check for low memory corruption"
1262         ---help---
1263           Periodically check for memory corruption in low memory, which
1264           is suspected to be caused by BIOS.  Even when enabled in the
1265           configuration, it is disabled at runtime.  Enable it by
1266           setting "memory_corruption_check=1" on the kernel command
1267           line.  By default it scans the low 64k of memory every 60
1268           seconds; see the memory_corruption_check_size and
1269           memory_corruption_check_period parameters in
1270           Documentation/kernel-parameters.txt to adjust this.
1271
1272           When enabled with the default parameters, this option has
1273           almost no overhead, as it reserves a relatively small amount
1274           of memory and scans it infrequently.  It both detects corruption
1275           and prevents it from affecting the running system.
1276
1277           It is, however, intended as a diagnostic tool; if repeatable
1278           BIOS-originated corruption always affects the same memory,
1279           you can use memmap= to prevent the kernel from using that
1280           memory.
1281
1282 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1283         bool "Set the default setting of memory_corruption_check"
1284         depends on X86_CHECK_BIOS_CORRUPTION
1285         default y
1286         ---help---
1287           Set whether the default state of memory_corruption_check is
1288           on or off.
1289
1290 config X86_RESERVE_LOW_64K
1291         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1292         default y
1293         ---help---
1294           Reserve the first 64K of physical RAM on BIOSes that are known
1295           to potentially corrupt that memory range. A numbers of BIOSes are
1296           known to utilize this area during suspend/resume, so it must not
1297           be used by the kernel.
1298
1299           Set this to N if you are absolutely sure that you trust the BIOS
1300           to get all its memory reservations and usages right.
1301
1302           If you have doubts about the BIOS (e.g. suspend/resume does not
1303           work or there's kernel crashes after certain hardware hotplug
1304           events) and it's not AMI or Phoenix, then you might want to enable
1305           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1306           corruption patterns.
1307
1308           Say Y if unsure.
1309
1310 config MATH_EMULATION
1311         bool
1312         prompt "Math emulation" if X86_32
1313         ---help---
1314           Linux can emulate a math coprocessor (used for floating point
1315           operations) if you don't have one. 486DX and Pentium processors have
1316           a math coprocessor built in, 486SX and 386 do not, unless you added
1317           a 487DX or 387, respectively. (The messages during boot time can
1318           give you some hints here ["man dmesg"].) Everyone needs either a
1319           coprocessor or this emulation.
1320
1321           If you don't have a math coprocessor, you need to say Y here; if you
1322           say Y here even though you have a coprocessor, the coprocessor will
1323           be used nevertheless. (This behavior can be changed with the kernel
1324           command line option "no387", which comes handy if your coprocessor
1325           is broken. Try "man bootparam" or see the documentation of your boot
1326           loader (lilo or loadlin) about how to pass options to the kernel at
1327           boot time.) This means that it is a good idea to say Y here if you
1328           intend to use this kernel on different machines.
1329
1330           More information about the internals of the Linux math coprocessor
1331           emulation can be found in <file:arch/x86/math-emu/README>.
1332
1333           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1334           kernel, it won't hurt.
1335
1336 config MTRR
1337         bool
1338         default y
1339         prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1340         ---help---
1341           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1342           the Memory Type Range Registers (MTRRs) may be used to control
1343           processor access to memory ranges. This is most useful if you have
1344           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1345           allows bus write transfers to be combined into a larger transfer
1346           before bursting over the PCI/AGP bus. This can increase performance
1347           of image write operations 2.5 times or more. Saying Y here creates a
1348           /proc/mtrr file which may be used to manipulate your processor's
1349           MTRRs. Typically the X server should use this.
1350
1351           This code has a reasonably generic interface so that similar
1352           control registers on other processors can be easily supported
1353           as well:
1354
1355           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1356           Registers (ARRs) which provide a similar functionality to MTRRs. For
1357           these, the ARRs are used to emulate the MTRRs.
1358           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1359           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1360           write-combining. All of these processors are supported by this code
1361           and it makes sense to say Y here if you have one of them.
1362
1363           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1364           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1365           can lead to all sorts of problems, so it's good to say Y here.
1366
1367           You can safely say Y even if your machine doesn't have MTRRs, you'll
1368           just add about 9 KB to your kernel.
1369
1370           See <file:Documentation/x86/mtrr.txt> for more information.
1371
1372 config MTRR_SANITIZER
1373         def_bool y
1374         prompt "MTRR cleanup support"
1375         depends on MTRR
1376         ---help---
1377           Convert MTRR layout from continuous to discrete, so X drivers can
1378           add writeback entries.
1379
1380           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1381           The largest mtrr entry size for a continuous block can be set with
1382           mtrr_chunk_size.
1383
1384           If unsure, say Y.
1385
1386 config MTRR_SANITIZER_ENABLE_DEFAULT
1387         int "MTRR cleanup enable value (0-1)"
1388         range 0 1
1389         default "0"
1390         depends on MTRR_SANITIZER
1391         ---help---
1392           Enable mtrr cleanup default value
1393
1394 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1395         int "MTRR cleanup spare reg num (0-7)"
1396         range 0 7
1397         default "1"
1398         depends on MTRR_SANITIZER
1399         ---help---
1400           mtrr cleanup spare entries default, it can be changed via
1401           mtrr_spare_reg_nr=N on the kernel command line.
1402
1403 config X86_PAT
1404         bool
1405         default y
1406         prompt "x86 PAT support" if EMBEDDED
1407         depends on MTRR
1408         ---help---
1409           Use PAT attributes to setup page level cache control.
1410
1411           PATs are the modern equivalents of MTRRs and are much more
1412           flexible than MTRRs.
1413
1414           Say N here if you see bootup problems (boot crash, boot hang,
1415           spontaneous reboots) or a non-working video driver.
1416
1417           If unsure, say Y.
1418
1419 config ARCH_USES_PG_UNCACHED
1420         def_bool y
1421         depends on X86_PAT
1422
1423 config EFI
1424         bool "EFI runtime service support"
1425         depends on ACPI
1426         ---help---
1427           This enables the kernel to use EFI runtime services that are
1428           available (such as the EFI variable services).
1429
1430           This option is only useful on systems that have EFI firmware.
1431           In addition, you should use the latest ELILO loader available
1432           at <http://elilo.sourceforge.net> in order to take advantage
1433           of EFI runtime services. However, even with this option, the
1434           resultant kernel should continue to boot on existing non-EFI
1435           platforms.
1436
1437 config SECCOMP
1438         def_bool y
1439         prompt "Enable seccomp to safely compute untrusted bytecode"
1440         ---help---
1441           This kernel feature is useful for number crunching applications
1442           that may need to compute untrusted bytecode during their
1443           execution. By using pipes or other transports made available to
1444           the process as file descriptors supporting the read/write
1445           syscalls, it's possible to isolate those applications in
1446           their own address space using seccomp. Once seccomp is
1447           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1448           and the task is only allowed to execute a few safe syscalls
1449           defined by each seccomp mode.
1450
1451           If unsure, say Y. Only embedded should say N here.
1452
1453 config CC_STACKPROTECTOR
1454         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1455         ---help---
1456           This option turns on the -fstack-protector GCC feature. This
1457           feature puts, at the beginning of functions, a canary value on
1458           the stack just before the return address, and validates
1459           the value just before actually returning.  Stack based buffer
1460           overflows (that need to overwrite this return address) now also
1461           overwrite the canary, which gets detected and the attack is then
1462           neutralized via a kernel panic.
1463
1464           This feature requires gcc version 4.2 or above, or a distribution
1465           gcc with the feature backported. Older versions are automatically
1466           detected and for those versions, this configuration option is
1467           ignored. (and a warning is printed during bootup)
1468
1469 source kernel/Kconfig.hz
1470
1471 config KEXEC
1472         bool "kexec system call"
1473         ---help---
1474           kexec is a system call that implements the ability to shutdown your
1475           current kernel, and to start another kernel.  It is like a reboot
1476           but it is independent of the system firmware.   And like a reboot
1477           you can start any kernel with it, not just Linux.
1478
1479           The name comes from the similarity to the exec system call.
1480
1481           It is an ongoing process to be certain the hardware in a machine
1482           is properly shutdown, so do not be surprised if this code does not
1483           initially work for you.  It may help to enable device hotplugging
1484           support.  As of this writing the exact hardware interface is
1485           strongly in flux, so no good recommendation can be made.
1486
1487 config CRASH_DUMP
1488         bool "kernel crash dumps"
1489         depends on X86_64 || (X86_32 && HIGHMEM)
1490         ---help---
1491           Generate crash dump after being started by kexec.
1492           This should be normally only set in special crash dump kernels
1493           which are loaded in the main kernel with kexec-tools into
1494           a specially reserved region and then later executed after
1495           a crash by kdump/kexec. The crash dump kernel must be compiled
1496           to a memory address not used by the main kernel or BIOS using
1497           PHYSICAL_START, or it must be built as a relocatable image
1498           (CONFIG_RELOCATABLE=y).
1499           For more details see Documentation/kdump/kdump.txt
1500
1501 config KEXEC_JUMP
1502         bool "kexec jump (EXPERIMENTAL)"
1503         depends on EXPERIMENTAL
1504         depends on KEXEC && HIBERNATION
1505         ---help---
1506           Jump between original kernel and kexeced kernel and invoke
1507           code in physical address mode via KEXEC
1508
1509 config PHYSICAL_START
1510         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1511         default "0x1000000"
1512         ---help---
1513           This gives the physical address where the kernel is loaded.
1514
1515           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1516           bzImage will decompress itself to above physical address and
1517           run from there. Otherwise, bzImage will run from the address where
1518           it has been loaded by the boot loader and will ignore above physical
1519           address.
1520
1521           In normal kdump cases one does not have to set/change this option
1522           as now bzImage can be compiled as a completely relocatable image
1523           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1524           address. This option is mainly useful for the folks who don't want
1525           to use a bzImage for capturing the crash dump and want to use a
1526           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1527           to be specifically compiled to run from a specific memory area
1528           (normally a reserved region) and this option comes handy.
1529
1530           So if you are using bzImage for capturing the crash dump,
1531           leave the value here unchanged to 0x1000000 and set
1532           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1533           for capturing the crash dump change this value to start of
1534           the reserved region.  In other words, it can be set based on
1535           the "X" value as specified in the "crashkernel=YM@XM"
1536           command line boot parameter passed to the panic-ed
1537           kernel. Please take a look at Documentation/kdump/kdump.txt
1538           for more details about crash dumps.
1539
1540           Usage of bzImage for capturing the crash dump is recommended as
1541           one does not have to build two kernels. Same kernel can be used
1542           as production kernel and capture kernel. Above option should have
1543           gone away after relocatable bzImage support is introduced. But it
1544           is present because there are users out there who continue to use
1545           vmlinux for dump capture. This option should go away down the
1546           line.
1547
1548           Don't change this unless you know what you are doing.
1549
1550 config RELOCATABLE
1551         bool "Build a relocatable kernel"
1552         default y
1553         ---help---
1554           This builds a kernel image that retains relocation information
1555           so it can be loaded someplace besides the default 1MB.
1556           The relocations tend to make the kernel binary about 10% larger,
1557           but are discarded at runtime.
1558
1559           One use is for the kexec on panic case where the recovery kernel
1560           must live at a different physical address than the primary
1561           kernel.
1562
1563           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1564           it has been loaded at and the compile time physical address
1565           (CONFIG_PHYSICAL_START) is ignored.
1566
1567 # Relocation on x86-32 needs some additional build support
1568 config X86_NEED_RELOCS
1569         def_bool y
1570         depends on X86_32 && RELOCATABLE
1571
1572 config PHYSICAL_ALIGN
1573         hex
1574         prompt "Alignment value to which kernel should be aligned" if X86_32
1575         default "0x1000000"
1576         range 0x2000 0x1000000
1577         ---help---
1578           This value puts the alignment restrictions on physical address
1579           where kernel is loaded and run from. Kernel is compiled for an
1580           address which meets above alignment restriction.
1581
1582           If bootloader loads the kernel at a non-aligned address and
1583           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1584           address aligned to above value and run from there.
1585
1586           If bootloader loads the kernel at a non-aligned address and
1587           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1588           load address and decompress itself to the address it has been
1589           compiled for and run from there. The address for which kernel is
1590           compiled already meets above alignment restrictions. Hence the
1591           end result is that kernel runs from a physical address meeting
1592           above alignment restrictions.
1593
1594           Don't change this unless you know what you are doing.
1595
1596 config HOTPLUG_CPU
1597         bool "Support for hot-pluggable CPUs"
1598         depends on SMP && HOTPLUG
1599         ---help---
1600           Say Y here to allow turning CPUs off and on. CPUs can be
1601           controlled through /sys/devices/system/cpu.
1602           ( Note: power management support will enable this option
1603             automatically on SMP systems. )
1604           Say N if you want to disable CPU hotplug.
1605
1606 config COMPAT_VDSO
1607         def_bool y
1608         prompt "Compat VDSO support"
1609         depends on X86_32 || IA32_EMULATION
1610         ---help---
1611           Map the 32-bit VDSO to the predictable old-style address too.
1612
1613           Say N here if you are running a sufficiently recent glibc
1614           version (2.3.3 or later), to remove the high-mapped
1615           VDSO mapping and to exclusively use the randomized VDSO.
1616
1617           If unsure, say Y.
1618
1619 config CMDLINE_BOOL
1620         bool "Built-in kernel command line"
1621         default n
1622         ---help---
1623           Allow for specifying boot arguments to the kernel at
1624           build time.  On some systems (e.g. embedded ones), it is
1625           necessary or convenient to provide some or all of the
1626           kernel boot arguments with the kernel itself (that is,
1627           to not rely on the boot loader to provide them.)
1628
1629           To compile command line arguments into the kernel,
1630           set this option to 'Y', then fill in the
1631           the boot arguments in CONFIG_CMDLINE.
1632
1633           Systems with fully functional boot loaders (i.e. non-embedded)
1634           should leave this option set to 'N'.
1635
1636 config CMDLINE
1637         string "Built-in kernel command string"
1638         depends on CMDLINE_BOOL
1639         default ""
1640         ---help---
1641           Enter arguments here that should be compiled into the kernel
1642           image and used at boot time.  If the boot loader provides a
1643           command line at boot time, it is appended to this string to
1644           form the full kernel command line, when the system boots.
1645
1646           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1647           change this behavior.
1648
1649           In most cases, the command line (whether built-in or provided
1650           by the boot loader) should specify the device for the root
1651           file system.
1652
1653 config CMDLINE_OVERRIDE
1654         bool "Built-in command line overrides boot loader arguments"
1655         default n
1656         depends on CMDLINE_BOOL
1657         ---help---
1658           Set this option to 'Y' to have the kernel ignore the boot loader
1659           command line, and use ONLY the built-in command line.
1660
1661           This is used to work around broken boot loaders.  This should
1662           be set to 'N' under normal conditions.
1663
1664 endmenu
1665
1666 config ARCH_ENABLE_MEMORY_HOTPLUG
1667         def_bool y
1668         depends on X86_64 || (X86_32 && HIGHMEM)
1669
1670 config ARCH_ENABLE_MEMORY_HOTREMOVE
1671         def_bool y
1672         depends on MEMORY_HOTPLUG
1673
1674 config HAVE_ARCH_EARLY_PFN_TO_NID
1675         def_bool X86_64
1676         depends on NUMA
1677
1678 menu "Power management and ACPI options"
1679
1680 config ARCH_HIBERNATION_HEADER
1681         def_bool y
1682         depends on X86_64 && HIBERNATION
1683
1684 source "kernel/power/Kconfig"
1685
1686 source "drivers/acpi/Kconfig"
1687
1688 source "drivers/sfi/Kconfig"
1689
1690 config X86_APM_BOOT
1691         bool
1692         default y
1693         depends on APM || APM_MODULE
1694
1695 menuconfig APM
1696         tristate "APM (Advanced Power Management) BIOS support"
1697         depends on X86_32 && PM_SLEEP
1698         ---help---
1699           APM is a BIOS specification for saving power using several different
1700           techniques. This is mostly useful for battery powered laptops with
1701           APM compliant BIOSes. If you say Y here, the system time will be
1702           reset after a RESUME operation, the /proc/apm device will provide
1703           battery status information, and user-space programs will receive
1704           notification of APM "events" (e.g. battery status change).
1705
1706           If you select "Y" here, you can disable actual use of the APM
1707           BIOS by passing the "apm=off" option to the kernel at boot time.
1708
1709           Note that the APM support is almost completely disabled for
1710           machines with more than one CPU.
1711
1712           In order to use APM, you will need supporting software. For location
1713           and more information, read <file:Documentation/power/pm.txt> and the
1714           Battery Powered Linux mini-HOWTO, available from
1715           <http://www.tldp.org/docs.html#howto>.
1716
1717           This driver does not spin down disk drives (see the hdparm(8)
1718           manpage ("man 8 hdparm") for that), and it doesn't turn off
1719           VESA-compliant "green" monitors.
1720
1721           This driver does not support the TI 4000M TravelMate and the ACER
1722           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1723           desktop machines also don't have compliant BIOSes, and this driver
1724           may cause those machines to panic during the boot phase.
1725
1726           Generally, if you don't have a battery in your machine, there isn't
1727           much point in using this driver and you should say N. If you get
1728           random kernel OOPSes or reboots that don't seem to be related to
1729           anything, try disabling/enabling this option (or disabling/enabling
1730           APM in your BIOS).
1731
1732           Some other things you should try when experiencing seemingly random,
1733           "weird" problems:
1734
1735           1) make sure that you have enough swap space and that it is
1736           enabled.
1737           2) pass the "no-hlt" option to the kernel
1738           3) switch on floating point emulation in the kernel and pass
1739           the "no387" option to the kernel
1740           4) pass the "floppy=nodma" option to the kernel
1741           5) pass the "mem=4M" option to the kernel (thereby disabling
1742           all but the first 4 MB of RAM)
1743           6) make sure that the CPU is not over clocked.
1744           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1745           8) disable the cache from your BIOS settings
1746           9) install a fan for the video card or exchange video RAM
1747           10) install a better fan for the CPU
1748           11) exchange RAM chips
1749           12) exchange the motherboard.
1750
1751           To compile this driver as a module, choose M here: the
1752           module will be called apm.
1753
1754 if APM
1755
1756 config APM_IGNORE_USER_SUSPEND
1757         bool "Ignore USER SUSPEND"
1758         ---help---
1759           This option will ignore USER SUSPEND requests. On machines with a
1760           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1761           series notebooks, it is necessary to say Y because of a BIOS bug.
1762
1763 config APM_DO_ENABLE
1764         bool "Enable PM at boot time"
1765         ---help---
1766           Enable APM features at boot time. From page 36 of the APM BIOS
1767           specification: "When disabled, the APM BIOS does not automatically
1768           power manage devices, enter the Standby State, enter the Suspend
1769           State, or take power saving steps in response to CPU Idle calls."
1770           This driver will make CPU Idle calls when Linux is idle (unless this
1771           feature is turned off -- see "Do CPU IDLE calls", below). This
1772           should always save battery power, but more complicated APM features
1773           will be dependent on your BIOS implementation. You may need to turn
1774           this option off if your computer hangs at boot time when using APM
1775           support, or if it beeps continuously instead of suspending. Turn
1776           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1777           T400CDT. This is off by default since most machines do fine without
1778           this feature.
1779
1780 config APM_CPU_IDLE
1781         bool "Make CPU Idle calls when idle"
1782         ---help---
1783           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1784           On some machines, this can activate improved power savings, such as
1785           a slowed CPU clock rate, when the machine is idle. These idle calls
1786           are made after the idle loop has run for some length of time (e.g.,
1787           333 mS). On some machines, this will cause a hang at boot time or
1788           whenever the CPU becomes idle. (On machines with more than one CPU,
1789           this option does nothing.)
1790
1791 config APM_DISPLAY_BLANK
1792         bool "Enable console blanking using APM"
1793         ---help---
1794           Enable console blanking using the APM. Some laptops can use this to
1795           turn off the LCD backlight when the screen blanker of the Linux
1796           virtual console blanks the screen. Note that this is only used by
1797           the virtual console screen blanker, and won't turn off the backlight
1798           when using the X Window system. This also doesn't have anything to
1799           do with your VESA-compliant power-saving monitor. Further, this
1800           option doesn't work for all laptops -- it might not turn off your
1801           backlight at all, or it might print a lot of errors to the console,
1802           especially if you are using gpm.
1803
1804 config APM_ALLOW_INTS
1805         bool "Allow interrupts during APM BIOS calls"
1806         ---help---
1807           Normally we disable external interrupts while we are making calls to
1808           the APM BIOS as a measure to lessen the effects of a badly behaving
1809           BIOS implementation.  The BIOS should reenable interrupts if it
1810           needs to.  Unfortunately, some BIOSes do not -- especially those in
1811           many of the newer IBM Thinkpads.  If you experience hangs when you
1812           suspend, try setting this to Y.  Otherwise, say N.
1813
1814 endif # APM
1815
1816 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1817
1818 source "drivers/cpuidle/Kconfig"
1819
1820 source "drivers/idle/Kconfig"
1821
1822 endmenu
1823
1824
1825 menu "Bus options (PCI etc.)"
1826
1827 config PCI
1828         bool "PCI support"
1829         default y
1830         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1831         ---help---
1832           Find out whether you have a PCI motherboard. PCI is the name of a
1833           bus system, i.e. the way the CPU talks to the other stuff inside
1834           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1835           VESA. If you have PCI, say Y, otherwise N.
1836
1837 choice
1838         prompt "PCI access mode"
1839         depends on X86_32 && PCI
1840         default PCI_GOANY
1841         ---help---
1842           On PCI systems, the BIOS can be used to detect the PCI devices and
1843           determine their configuration. However, some old PCI motherboards
1844           have BIOS bugs and may crash if this is done. Also, some embedded
1845           PCI-based systems don't have any BIOS at all. Linux can also try to
1846           detect the PCI hardware directly without using the BIOS.
1847
1848           With this option, you can specify how Linux should detect the
1849           PCI devices. If you choose "BIOS", the BIOS will be used,
1850           if you choose "Direct", the BIOS won't be used, and if you
1851           choose "MMConfig", then PCI Express MMCONFIG will be used.
1852           If you choose "Any", the kernel will try MMCONFIG, then the
1853           direct access method and falls back to the BIOS if that doesn't
1854           work. If unsure, go with the default, which is "Any".
1855
1856 config PCI_GOBIOS
1857         bool "BIOS"
1858
1859 config PCI_GOMMCONFIG
1860         bool "MMConfig"
1861
1862 config PCI_GODIRECT
1863         bool "Direct"
1864
1865 config PCI_GOOLPC
1866         bool "OLPC"
1867         depends on OLPC
1868
1869 config PCI_GOANY
1870         bool "Any"
1871
1872 endchoice
1873
1874 config PCI_BIOS
1875         def_bool y
1876         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1877
1878 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1879 config PCI_DIRECT
1880         def_bool y
1881         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1882
1883 config PCI_MMCONFIG
1884         def_bool y
1885         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1886
1887 config PCI_OLPC
1888         def_bool y
1889         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1890
1891 config PCI_DOMAINS
1892         def_bool y
1893         depends on PCI
1894
1895 config PCI_MMCONFIG
1896         bool "Support mmconfig PCI config space access"
1897         depends on X86_64 && PCI && ACPI
1898
1899 config DMAR
1900         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1901         depends on PCI_MSI && ACPI && EXPERIMENTAL
1902         help
1903           DMA remapping (DMAR) devices support enables independent address
1904           translations for Direct Memory Access (DMA) from devices.
1905           These DMA remapping devices are reported via ACPI tables
1906           and include PCI device scope covered by these DMA
1907           remapping devices.
1908
1909 config DMAR_DEFAULT_ON
1910         def_bool y
1911         prompt "Enable DMA Remapping Devices by default"
1912         depends on DMAR
1913         help
1914           Selecting this option will enable a DMAR device at boot time if
1915           one is found. If this option is not selected, DMAR support can
1916           be enabled by passing intel_iommu=on to the kernel. It is
1917           recommended you say N here while the DMAR code remains
1918           experimental.
1919
1920 config DMAR_BROKEN_GFX_WA
1921         def_bool n
1922         prompt "Workaround broken graphics drivers (going away soon)"
1923         depends on DMAR && BROKEN
1924         ---help---
1925           Current Graphics drivers tend to use physical address
1926           for DMA and avoid using DMA APIs. Setting this config
1927           option permits the IOMMU driver to set a unity map for
1928           all the OS-visible memory. Hence the driver can continue
1929           to use physical addresses for DMA, at least until this
1930           option is removed in the 2.6.32 kernel.
1931
1932 config DMAR_FLOPPY_WA
1933         def_bool y
1934         depends on DMAR
1935         ---help---
1936           Floppy disk drivers are known to bypass DMA API calls
1937           thereby failing to work when IOMMU is enabled. This
1938           workaround will setup a 1:1 mapping for the first
1939           16MiB to make floppy (an ISA device) work.
1940
1941 config INTR_REMAP
1942         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1943         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1944         ---help---
1945           Supports Interrupt remapping for IO-APIC and MSI devices.
1946           To use x2apic mode in the CPU's which support x2APIC enhancements or
1947           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1948
1949 source "drivers/pci/pcie/Kconfig"
1950
1951 source "drivers/pci/Kconfig"
1952
1953 # x86_64 have no ISA slots, but do have ISA-style DMA.
1954 config ISA_DMA_API
1955         def_bool y
1956
1957 if X86_32
1958
1959 config ISA
1960         bool "ISA support"
1961         ---help---
1962           Find out whether you have ISA slots on your motherboard.  ISA is the
1963           name of a bus system, i.e. the way the CPU talks to the other stuff
1964           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1965           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1966           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1967
1968 config EISA
1969         bool "EISA support"
1970         depends on ISA
1971         ---help---
1972           The Extended Industry Standard Architecture (EISA) bus was
1973           developed as an open alternative to the IBM MicroChannel bus.
1974
1975           The EISA bus provided some of the features of the IBM MicroChannel
1976           bus while maintaining backward compatibility with cards made for
1977           the older ISA bus.  The EISA bus saw limited use between 1988 and
1978           1995 when it was made obsolete by the PCI bus.
1979
1980           Say Y here if you are building a kernel for an EISA-based machine.
1981
1982           Otherwise, say N.
1983
1984 source "drivers/eisa/Kconfig"
1985
1986 config MCA
1987         bool "MCA support"
1988         ---help---
1989           MicroChannel Architecture is found in some IBM PS/2 machines and
1990           laptops.  It is a bus system similar to PCI or ISA. See
1991           <file:Documentation/mca.txt> (and especially the web page given
1992           there) before attempting to build an MCA bus kernel.
1993
1994 source "drivers/mca/Kconfig"
1995
1996 config SCx200
1997         tristate "NatSemi SCx200 support"
1998         ---help---
1999           This provides basic support for National Semiconductor's
2000           (now AMD's) Geode processors.  The driver probes for the
2001           PCI-IDs of several on-chip devices, so its a good dependency
2002           for other scx200_* drivers.
2003
2004           If compiled as a module, the driver is named scx200.
2005
2006 config SCx200HR_TIMER
2007         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2008         depends on SCx200 && GENERIC_TIME
2009         default y
2010         ---help---
2011           This driver provides a clocksource built upon the on-chip
2012           27MHz high-resolution timer.  Its also a workaround for
2013           NSC Geode SC-1100's buggy TSC, which loses time when the
2014           processor goes idle (as is done by the scheduler).  The
2015           other workaround is idle=poll boot option.
2016
2017 config OLPC
2018         bool "One Laptop Per Child support"
2019         select GPIOLIB
2020         default n
2021         ---help---
2022           Add support for detecting the unique features of the OLPC
2023           XO hardware.
2024
2025 endif # X86_32
2026
2027 config K8_NB
2028         def_bool y
2029         depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2030
2031 source "drivers/pcmcia/Kconfig"
2032
2033 source "drivers/pci/hotplug/Kconfig"
2034
2035 endmenu
2036
2037
2038 menu "Executable file formats / Emulations"
2039
2040 source "fs/Kconfig.binfmt"
2041
2042 config IA32_EMULATION
2043         bool "IA32 Emulation"
2044         depends on X86_64
2045         select COMPAT_BINFMT_ELF
2046         ---help---
2047           Include code to run 32-bit programs under a 64-bit kernel. You should
2048           likely turn this on, unless you're 100% sure that you don't have any
2049           32-bit programs left.
2050
2051 config IA32_AOUT
2052         tristate "IA32 a.out support"
2053         depends on IA32_EMULATION
2054         ---help---
2055           Support old a.out binaries in the 32bit emulation.
2056
2057 config COMPAT
2058         def_bool y
2059         depends on IA32_EMULATION
2060
2061 config COMPAT_FOR_U64_ALIGNMENT
2062         def_bool COMPAT
2063         depends on X86_64
2064
2065 config SYSVIPC_COMPAT
2066         def_bool y
2067         depends on COMPAT && SYSVIPC
2068
2069 endmenu
2070
2071
2072 config HAVE_ATOMIC_IOMAP
2073         def_bool y
2074         depends on X86_32
2075
2076 source "net/Kconfig"
2077
2078 source "drivers/Kconfig"
2079
2080 source "drivers/firmware/Kconfig"
2081
2082 source "fs/Kconfig"
2083
2084 source "arch/x86/Kconfig.debug"
2085
2086 source "security/Kconfig"
2087
2088 source "crypto/Kconfig"
2089
2090 source "arch/x86/kvm/Kconfig"
2091
2092 source "lib/Kconfig"