arch/x86/Kconfig

   1 # x86 configuration
   2 mainmenu "Linux Kernel Configuration for x86"
   3
   4 # Select 32 or 64 bit
   5 config 64BIT
   6         bool "64-bit kernel" if ARCH = "x86"
   7         default ARCH = "x86_64"
   8         ---help---
   9           Say yes to build a 64-bit kernel - formerly known as x86_64
  10           Say no to build a 32-bit kernel - formerly known as i386
  11
  12 config X86_32
  13         def_bool !64BIT
  14
  15 config X86_64
  16         def_bool 64BIT
  17
  18 ### Arch settings
  19 config X86
  20         def_bool y
  21         select HAVE_AOUT if X86_32
  22         select HAVE_READQ
  23         select HAVE_WRITEQ
  24         select HAVE_UNSTABLE_SCHED_CLOCK
  25         select HAVE_IDE
  26         select HAVE_OPROFILE
  27         select HAVE_IOREMAP_PROT
  28         select HAVE_KPROBES
  29         select ARCH_WANT_OPTIONAL_GPIOLIB
  30         select ARCH_WANT_FRAME_POINTERS
  31         select HAVE_KRETPROBES
  32         select HAVE_FTRACE_MCOUNT_RECORD
  33         select HAVE_DYNAMIC_FTRACE
  34         select HAVE_FUNCTION_TRACER
  35         select HAVE_FUNCTION_GRAPH_TRACER
  36         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  37         select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  38         select HAVE_FTRACE_SYSCALLS
  39         select HAVE_KVM
  40         select HAVE_ARCH_KGDB
  41         select HAVE_ARCH_TRACEHOOK
  42         select HAVE_GENERIC_DMA_COHERENT if X86_32
  43         select HAVE_EFFICIENT_UNALIGNED_ACCESS
  44         select USER_STACKTRACE_SUPPORT
  45         select HAVE_DMA_API_DEBUG
  46         select HAVE_KERNEL_GZIP
  47         select HAVE_KERNEL_BZIP2
  48         select HAVE_KERNEL_LZMA
  49
  50 config ARCH_DEFCONFIG
  51         string
  52         default "arch/x86/configs/i386_defconfig" if X86_32
  53         default "arch/x86/configs/x86_64_defconfig" if X86_64
  54
  55 config GENERIC_TIME
  56         def_bool y
  57
  58 config GENERIC_CMOS_UPDATE
  59         def_bool y
  60
  61 config CLOCKSOURCE_WATCHDOG
  62         def_bool y
  63
  64 config GENERIC_CLOCKEVENTS
  65         def_bool y
  66
  67 config GENERIC_CLOCKEVENTS_BROADCAST
  68         def_bool y
  69         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  70
  71 config LOCKDEP_SUPPORT
  72         def_bool y
  73
  74 config STACKTRACE_SUPPORT
  75         def_bool y
  76
  77 config HAVE_LATENCYTOP_SUPPORT
  78         def_bool y
  79
  80 config FAST_CMPXCHG_LOCAL
  81         bool
  82         default y
  83
  84 config MMU
  85         def_bool y
  86
  87 config ZONE_DMA
  88         def_bool y
  89
  90 config SBUS
  91         bool
  92
  93 config GENERIC_ISA_DMA
  94         def_bool y
  95
  96 config GENERIC_IOMAP
  97         def_bool y
  98
  99 config GENERIC_BUG
 100         def_bool y
 101         depends on BUG
 102         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 103
 104 config GENERIC_BUG_RELATIVE_POINTERS
 105         bool
 106
 107 config GENERIC_HWEIGHT
 108         def_bool y
 109
 110 config GENERIC_GPIO
 111         bool
 112
 113 config ARCH_MAY_HAVE_PC_FDC
 114         def_bool y
 115
 116 config RWSEM_GENERIC_SPINLOCK
 117         def_bool !X86_XADD
 118
 119 config RWSEM_XCHGADD_ALGORITHM
 120         def_bool X86_XADD
 121
 122 config ARCH_HAS_CPU_IDLE_WAIT
 123         def_bool y
 124
 125 config GENERIC_CALIBRATE_DELAY
 126         def_bool y
 127
 128 config GENERIC_TIME_VSYSCALL
 129         bool
 130         default X86_64
 131
 132 config ARCH_HAS_CPU_RELAX
 133         def_bool y
 134
 135 config ARCH_HAS_DEFAULT_IDLE
 136         def_bool y
 137
 138 config ARCH_HAS_CACHE_LINE_SIZE
 139         def_bool y
 140
 141 config HAVE_SETUP_PER_CPU_AREA
 142         def_bool y
 143
 144 config HAVE_DYNAMIC_PER_CPU_AREA
 145         def_bool y
 146
 147 config HAVE_CPUMASK_OF_CPU_MAP
 148         def_bool X86_64_SMP
 149
 150 config ARCH_HIBERNATION_POSSIBLE
 151         def_bool y
 152
 153 config ARCH_SUSPEND_POSSIBLE
 154         def_bool y
 155
 156 config ZONE_DMA32
 157         bool
 158         default X86_64
 159
 160 config ARCH_POPULATES_NODE_MAP
 161         def_bool y
 162
 163 config AUDIT_ARCH
 164         bool
 165         default X86_64
 166
 167 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 168         def_bool y
 169
 170 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 171         def_bool y
 172
 173 # Use the generic interrupt handling code in kernel/irq/:
 174 config GENERIC_HARDIRQS
 175         bool
 176         default y
 177
 178 config GENERIC_HARDIRQS_NO__DO_IRQ
 179        def_bool y
 180
 181 config GENERIC_IRQ_PROBE
 182         bool
 183         default y
 184
 185 config GENERIC_PENDING_IRQ
 186         bool
 187         depends on GENERIC_HARDIRQS && SMP
 188         default y
 189
 190 config USE_GENERIC_SMP_HELPERS
 191         def_bool y
 192         depends on SMP
 193
 194 config X86_32_SMP
 195         def_bool y
 196         depends on X86_32 && SMP
 197
 198 config X86_64_SMP
 199         def_bool y
 200         depends on X86_64 && SMP
 201
 202 config X86_HT
 203         bool
 204         depends on SMP
 205         default y
 206
 207 config X86_TRAMPOLINE
 208         bool
 209         depends on SMP || (64BIT && ACPI_SLEEP)
 210         default y
 211
 212 config X86_32_LAZY_GS
 213         def_bool y
 214         depends on X86_32 && !CC_STACKPROTECTOR
 215
 216 config KTIME_SCALAR
 217         def_bool X86_32
 218 source "init/Kconfig"
 219 source "kernel/Kconfig.freezer"
 220
 221 menu "Processor type and features"
 222
 223 source "kernel/time/Kconfig"
 224
 225 config SMP
 226         bool "Symmetric multi-processing support"
 227         ---help---
 228           This enables support for systems with more than one CPU. If you have
 229           a system with only one CPU, like most personal computers, say N. If
 230           you have a system with more than one CPU, say Y.
 231
 232           If you say N here, the kernel will run on single and multiprocessor
 233           machines, but will use only one CPU of a multiprocessor machine. If
 234           you say Y here, the kernel will run on many, but not all,
 235           singleprocessor machines. On a singleprocessor machine, the kernel
 236           will run faster if you say N here.
 237
 238           Note that if you say Y here and choose architecture "586" or
 239           "Pentium" under "Processor family", the kernel will not work on 486
 240           architectures. Similarly, multiprocessor kernels for the "PPro"
 241           architecture may not work on all Pentium based boards.
 242
 243           People using multiprocessor machines who say Y here should also say
 244           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 245           Management" code will be disabled if you say Y here.
 246
 247           See also <file:Documentation/i386/IO-APIC.txt>,
 248           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 249           <http://www.tldp.org/docs.html#howto>.
 250
 251           If you don't know what to do here, say N.
 252
 253 config X86_X2APIC
 254         bool "Support x2apic"
 255         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 256         ---help---
 257           This enables x2apic support on CPUs that have this feature.
 258
 259           This allows 32-bit apic IDs (so it can support very large systems),
 260           and accesses the local apic via MSRs not via mmio.
 261
 262           If you don't know what to do here, say N.
 263
 264 config SPARSE_IRQ
 265         bool "Support sparse irq numbering"
 266         depends on PCI_MSI || HT_IRQ
 267         ---help---
 268           This enables support for sparse irqs. This is useful for distro
 269           kernels that want to define a high CONFIG_NR_CPUS value but still
 270           want to have low kernel memory footprint on smaller machines.
 271
 272           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 273             out the irq_desc[] array in a more NUMA-friendly way. )
 274
 275           If you don't know what to do here, say N.
 276
 277 config NUMA_MIGRATE_IRQ_DESC
 278         bool "Move irq desc when changing irq smp_affinity"
 279         depends on SPARSE_IRQ && NUMA
 280         depends on BROKEN
 281         default n
 282         ---help---
 283           This enables moving irq_desc to cpu/node that irq will use handled.
 284
 285           If you don't know what to do here, say N.
 286
 287 config X86_MPPARSE
 288         bool "Enable MPS table" if ACPI
 289         default y
 290         depends on X86_LOCAL_APIC
 291         ---help---
 292           For old smp systems that do not have proper acpi support. Newer systems
 293           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 294
 295 config X86_BIGSMP
 296         bool "Support for big SMP systems with more than 8 CPUs"
 297         depends on X86_32 && SMP
 298         ---help---
 299           This option is needed for the systems that have more than 8 CPUs
 300
 301 if X86_32
 302 config X86_EXTENDED_PLATFORM
 303         bool "Support for extended (non-PC) x86 platforms"
 304         default y
 305         ---help---
 306           If you disable this option then the kernel will only support
 307           standard PC platforms. (which covers the vast majority of
 308           systems out there.)
 309
 310           If you enable this option then you'll be able to select support
 311           for the following (non-PC) 32 bit x86 platforms:
 312                 AMD Elan
 313                 NUMAQ (IBM/Sequent)
 314                 RDC R-321x SoC
 315                 SGI 320/540 (Visual Workstation)
 316                 Summit/EXA (IBM x440)
 317                 Unisys ES7000 IA32 series
 318
 319           If you have one of these systems, or if you want to build a
 320           generic distribution kernel, say Y here - otherwise say N.
 321 endif
 322
 323 if X86_64
 324 config X86_EXTENDED_PLATFORM
 325         bool "Support for extended (non-PC) x86 platforms"
 326         default y
 327         ---help---
 328           If you disable this option then the kernel will only support
 329           standard PC platforms. (which covers the vast majority of
 330           systems out there.)
 331
 332           If you enable this option then you'll be able to select support
 333           for the following (non-PC) 64 bit x86 platforms:
 334                 ScaleMP vSMP
 335                 SGI Ultraviolet
 336
 337           If you have one of these systems, or if you want to build a
 338           generic distribution kernel, say Y here - otherwise say N.
 339 endif
 340 # This is an alphabetically sorted list of 64 bit extended platforms
 341 # Please maintain the alphabetic order if and when there are additions
 342
 343 config X86_VSMP
 344         bool "ScaleMP vSMP"
 345         select PARAVIRT
 346         depends on X86_64 && PCI
 347         depends on X86_EXTENDED_PLATFORM
 348         ---help---
 349           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 350           supposed to run on these EM64T-based machines.  Only choose this option
 351           if you have one of these machines.
 352
 353 config X86_UV
 354         bool "SGI Ultraviolet"
 355         depends on X86_64
 356         depends on X86_EXTENDED_PLATFORM
 357         depends on NUMA
 358         select X86_X2APIC
 359         ---help---
 360           This option is needed in order to support SGI Ultraviolet systems.
 361           If you don't have one of these, you should say N here.
 362
 363 # Following is an alphabetically sorted list of 32 bit extended platforms
 364 # Please maintain the alphabetic order if and when there are additions
 365
 366 config X86_ELAN
 367         bool "AMD Elan"
 368         depends on X86_32
 369         depends on X86_EXTENDED_PLATFORM
 370         ---help---
 371           Select this for an AMD Elan processor.
 372
 373           Do not use this option for K6/Athlon/Opteron processors!
 374
 375           If unsure, choose "PC-compatible" instead.
 376
 377 config X86_RDC321X
 378         bool "RDC R-321x SoC"
 379         depends on X86_32
 380         depends on X86_EXTENDED_PLATFORM
 381         select M486
 382         select X86_REBOOTFIXUPS
 383         ---help---
 384           This option is needed for RDC R-321x system-on-chip, also known
 385           as R-8610-(G).
 386           If you don't have one of these chips, you should say N here.
 387
 388 config X86_32_NON_STANDARD
 389         bool "Support non-standard 32-bit SMP architectures"
 390         depends on X86_32 && SMP
 391         depends on X86_EXTENDED_PLATFORM
 392         ---help---
 393           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 394           subarchitectures.  It is intended for a generic binary kernel.
 395           if you select them all, kernel will probe it one by one. and will
 396           fallback to default.
 397
 398 # Alphabetically sorted list of Non standard 32 bit platforms
 399
 400 config X86_NUMAQ
 401         bool "NUMAQ (IBM/Sequent)"
 402         depends on X86_32_NON_STANDARD
 403         select NUMA
 404         select X86_MPPARSE
 405         ---help---
 406           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 407           NUMA multiquad box. This changes the way that processors are
 408           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 409           of Flat Logical.  You will need a new lynxer.elf file to flash your
 410           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 411
 412 config X86_VISWS
 413         bool "SGI 320/540 (Visual Workstation)"
 414         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 415         depends on X86_32_NON_STANDARD
 416         ---help---
 417           The SGI Visual Workstation series is an IA32-based workstation
 418           based on SGI systems chips with some legacy PC hardware attached.
 419
 420           Say Y here to create a kernel to run on the SGI 320 or 540.
 421
 422           A kernel compiled for the Visual Workstation will run on general
 423           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 424
 425 config X86_SUMMIT
 426         bool "Summit/EXA (IBM x440)"
 427         depends on X86_32_NON_STANDARD
 428         ---help---
 429           This option is needed for IBM systems that use the Summit/EXA chipset.
 430           In particular, it is needed for the x440.
 431
 432 config X86_ES7000
 433         bool "Unisys ES7000 IA32 series"
 434         depends on X86_32_NON_STANDARD && X86_BIGSMP
 435         ---help---
 436           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 437           supposed to run on an IA32-based Unisys ES7000 system.
 438
 439 config SCHED_OMIT_FRAME_POINTER
 440         def_bool y
 441         prompt "Single-depth WCHAN output"
 442         depends on X86
 443         ---help---
 444           Calculate simpler /proc/<PID>/wchan values. If this option
 445           is disabled then wchan values will recurse back to the
 446           caller function. This provides more accurate wchan values,
 447           at the expense of slightly more scheduling overhead.
 448
 449           If in doubt, say "Y".
 450
 451 menuconfig PARAVIRT_GUEST
 452         bool "Paravirtualized guest support"
 453         ---help---
 454           Say Y here to get to see options related to running Linux under
 455           various hypervisors.  This option alone does not add any kernel code.
 456
 457           If you say N, all options in this submenu will be skipped and disabled.
 458
 459 if PARAVIRT_GUEST
 460
 461 source "arch/x86/xen/Kconfig"
 462
 463 config VMI
 464         bool "VMI Guest support"
 465         select PARAVIRT
 466         depends on X86_32
 467         ---help---
 468           VMI provides a paravirtualized interface to the VMware ESX server
 469           (it could be used by other hypervisors in theory too, but is not
 470           at the moment), by linking the kernel to a GPL-ed ROM module
 471           provided by the hypervisor.
 472
 473 config KVM_CLOCK
 474         bool "KVM paravirtualized clock"
 475         select PARAVIRT
 476         select PARAVIRT_CLOCK
 477         ---help---
 478           Turning on this option will allow you to run a paravirtualized clock
 479           when running over the KVM hypervisor. Instead of relying on a PIT
 480           (or probably other) emulation by the underlying device model, the host
 481           provides the guest with timing infrastructure such as time of day, and
 482           system time
 483
 484 config KVM_GUEST
 485         bool "KVM Guest support"
 486         select PARAVIRT
 487         ---help---
 488           This option enables various optimizations for running under the KVM
 489           hypervisor.
 490
 491 source "arch/x86/lguest/Kconfig"
 492
 493 config PARAVIRT
 494         bool "Enable paravirtualization code"
 495         ---help---
 496           This changes the kernel so it can modify itself when it is run
 497           under a hypervisor, potentially improving performance significantly
 498           over full virtualization.  However, when run without a hypervisor
 499           the kernel is theoretically slower and slightly larger.
 500
 501 config PARAVIRT_CLOCK
 502         bool
 503         default n
 504
 505 endif
 506
 507 config PARAVIRT_DEBUG
 508         bool "paravirt-ops debugging"
 509         depends on PARAVIRT && DEBUG_KERNEL
 510         ---help---
 511           Enable to debug paravirt_ops internals.  Specifically, BUG if
 512           a paravirt_op is missing when it is called.
 513
 514 config MEMTEST
 515         bool "Memtest"
 516         ---help---
 517           This option adds a kernel parameter 'memtest', which allows memtest
 518           to be set.
 519                 memtest=0, mean disabled; -- default
 520                 memtest=1, mean do 1 test pattern;
 521                 ...
 522                 memtest=4, mean do 4 test patterns.
 523           If you are unsure how to answer this question, answer N.
 524
 525 config X86_SUMMIT_NUMA
 526         def_bool y
 527         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 528
 529 config X86_CYCLONE_TIMER
 530         def_bool y
 531         depends on X86_32_NON_STANDARD
 532
 533 source "arch/x86/Kconfig.cpu"
 534
 535 config HPET_TIMER
 536         def_bool X86_64
 537         prompt "HPET Timer Support" if X86_32
 538         ---help---
 539           Use the IA-PC HPET (High Precision Event Timer) to manage
 540           time in preference to the PIT and RTC, if a HPET is
 541           present.
 542           HPET is the next generation timer replacing legacy 8254s.
 543           The HPET provides a stable time base on SMP
 544           systems, unlike the TSC, but it is more expensive to access,
 545           as it is off-chip.  You can find the HPET spec at
 546           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 547
 548           You can safely choose Y here.  However, HPET will only be
 549           activated if the platform and the BIOS support this feature.
 550           Otherwise the 8254 will be used for timing services.
 551
 552           Choose N to continue using the legacy 8254 timer.
 553
 554 config HPET_EMULATE_RTC
 555         def_bool y
 556         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 557
 558 # Mark as embedded because too many people got it wrong.
 559 # The code disables itself when not needed.
 560 config DMI
 561         default y
 562         bool "Enable DMI scanning" if EMBEDDED
 563         ---help---
 564           Enabled scanning of DMI to identify machine quirks. Say Y
 565           here unless you have verified that your setup is not
 566           affected by entries in the DMI blacklist. Required by PNP
 567           BIOS code.
 568
 569 config GART_IOMMU
 570         bool "GART IOMMU support" if EMBEDDED
 571         default y
 572         select SWIOTLB
 573         select AGP
 574         depends on X86_64 && PCI
 575         ---help---
 576           Support for full DMA access of devices with 32bit memory access only
 577           on systems with more than 3GB. This is usually needed for USB,
 578           sound, many IDE/SATA chipsets and some other devices.
 579           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 580           based hardware IOMMU and a software bounce buffer based IOMMU used
 581           on Intel systems and as fallback.
 582           The code is only active when needed (enough memory and limited
 583           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 584           too.
 585
 586 config CALGARY_IOMMU
 587         bool "IBM Calgary IOMMU support"
 588         select SWIOTLB
 589         depends on X86_64 && PCI && EXPERIMENTAL
 590         ---help---
 591           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 592           systems. Needed to run systems with more than 3GB of memory
 593           properly with 32-bit PCI devices that do not support DAC
 594           (Double Address Cycle). Calgary also supports bus level
 595           isolation, where all DMAs pass through the IOMMU.  This
 596           prevents them from going anywhere except their intended
 597           destination. This catches hard-to-find kernel bugs and
 598           mis-behaving drivers and devices that do not use the DMA-API
 599           properly to set up their DMA buffers.  The IOMMU can be
 600           turned off at boot time with the iommu=off parameter.
 601           Normally the kernel will make the right choice by itself.
 602           If unsure, say Y.
 603
 604 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 605         def_bool y
 606         prompt "Should Calgary be enabled by default?"
 607         depends on CALGARY_IOMMU
 608         ---help---
 609           Should Calgary be enabled by default? if you choose 'y', Calgary
 610           will be used (if it exists). If you choose 'n', Calgary will not be
 611           used even if it exists. If you choose 'n' and would like to use
 612           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 613           If unsure, say Y.
 614
 615 config AMD_IOMMU
 616         bool "AMD IOMMU support"
 617         select SWIOTLB
 618         select PCI_MSI
 619         depends on X86_64 && PCI && ACPI
 620         ---help---
 621           With this option you can enable support for AMD IOMMU hardware in
 622           your system. An IOMMU is a hardware component which provides
 623           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 624           can isolate the the DMA memory of different devices and protect the
 625           system from misbehaving device drivers or hardware.
 626
 627           You can find out if your system has an AMD IOMMU if you look into
 628           your BIOS for an option to enable it or if you have an IVRS ACPI
 629           table.
 630
 631 config AMD_IOMMU_STATS
 632         bool "Export AMD IOMMU statistics to debugfs"
 633         depends on AMD_IOMMU
 634         select DEBUG_FS
 635         ---help---
 636           This option enables code in the AMD IOMMU driver to collect various
 637           statistics about whats happening in the driver and exports that
 638           information to userspace via debugfs.
 639           If unsure, say N.
 640
 641 # need this always selected by IOMMU for the VIA workaround
 642 config SWIOTLB
 643         def_bool y if X86_64
 644         ---help---
 645           Support for software bounce buffers used on x86-64 systems
 646           which don't have a hardware IOMMU (e.g. the current generation
 647           of Intel's x86-64 CPUs). Using this PCI devices which can only
 648           access 32-bits of memory can be used on systems with more than
 649           3 GB of memory. If unsure, say Y.
 650
 651 config IOMMU_HELPER
 652         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 653
 654 config IOMMU_API
 655         def_bool (AMD_IOMMU || DMAR)
 656
 657 config MAXSMP
 658         bool "Configure Maximum number of SMP Processors and NUMA Nodes"
 659         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 660         select CPUMASK_OFFSTACK
 661         default n
 662         ---help---
 663           Configure maximum number of CPUS and NUMA Nodes for this architecture.
 664           If unsure, say N.
 665
 666 config NR_CPUS
 667         int "Maximum number of CPUs" if SMP && !MAXSMP
 668         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 669         range 2 512 if SMP && !MAXSMP
 670         default "1" if !SMP
 671         default "4096" if MAXSMP
 672         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 673         default "8" if SMP
 674         ---help---
 675           This allows you to specify the maximum number of CPUs which this
 676           kernel will support.  The maximum supported value is 512 and the
 677           minimum value which makes sense is 2.
 678
 679           This is purely to save memory - each supported CPU adds
 680           approximately eight kilobytes to the kernel image.
 681
 682 config SCHED_SMT
 683         bool "SMT (Hyperthreading) scheduler support"
 684         depends on X86_HT
 685         ---help---
 686           SMT scheduler support improves the CPU scheduler's decision making
 687           when dealing with Intel Pentium 4 chips with HyperThreading at a
 688           cost of slightly increased overhead in some places. If unsure say
 689           N here.
 690
 691 config SCHED_MC
 692         def_bool y
 693         prompt "Multi-core scheduler support"
 694         depends on X86_HT
 695         ---help---
 696           Multi-core scheduler support improves the CPU scheduler's decision
 697           making when dealing with multi-core CPU chips at a cost of slightly
 698           increased overhead in some places. If unsure say N here.
 699
 700 source "kernel/Kconfig.preempt"
 701
 702 config X86_UP_APIC
 703         bool "Local APIC support on uniprocessors"
 704         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 705         ---help---
 706           A local APIC (Advanced Programmable Interrupt Controller) is an
 707           integrated interrupt controller in the CPU. If you have a single-CPU
 708           system which has a processor with a local APIC, you can say Y here to
 709           enable and use it. If you say Y here even though your machine doesn't
 710           have a local APIC, then the kernel will still run with no slowdown at
 711           all. The local APIC supports CPU-generated self-interrupts (timer,
 712           performance counters), and the NMI watchdog which detects hard
 713           lockups.
 714
 715 config X86_UP_IOAPIC
 716         bool "IO-APIC support on uniprocessors"
 717         depends on X86_UP_APIC
 718         ---help---
 719           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 720           SMP-capable replacement for PC-style interrupt controllers. Most
 721           SMP systems and many recent uniprocessor systems have one.
 722
 723           If you have a single-CPU system with an IO-APIC, you can say Y here
 724           to use it. If you say Y here even though your machine doesn't have
 725           an IO-APIC, then the kernel will still run with no slowdown at all.
 726
 727 config X86_LOCAL_APIC
 728         def_bool y
 729         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 730
 731 config X86_IO_APIC
 732         def_bool y
 733         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 734
 735 config X86_VISWS_APIC
 736         def_bool y
 737         depends on X86_32 && X86_VISWS
 738
 739 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 740         bool "Reroute for broken boot IRQs"
 741         default n
 742         depends on X86_IO_APIC
 743         ---help---
 744           This option enables a workaround that fixes a source of
 745           spurious interrupts. This is recommended when threaded
 746           interrupt handling is used on systems where the generation of
 747           superfluous "boot interrupts" cannot be disabled.
 748
 749           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 750           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 751           kernel does during interrupt handling). On chipsets where this
 752           boot IRQ generation cannot be disabled, this workaround keeps
 753           the original IRQ line masked so that only the equivalent "boot
 754           IRQ" is delivered to the CPUs. The workaround also tells the
 755           kernel to set up the IRQ handler on the boot IRQ line. In this
 756           way only one interrupt is delivered to the kernel. Otherwise
 757           the spurious second interrupt may cause the kernel to bring
 758           down (vital) interrupt lines.
 759
 760           Only affects "broken" chipsets. Interrupt sharing may be
 761           increased on these systems.
 762
 763 config X86_MCE
 764         bool "Machine Check Exception"
 765         ---help---
 766           Machine Check Exception support allows the processor to notify the
 767           kernel if it detects a problem (e.g. overheating, component failure).
 768           The action the kernel takes depends on the severity of the problem,
 769           ranging from a warning message on the console, to halting the machine.
 770           Your processor must be a Pentium or newer to support this - check the
 771           flags in /proc/cpuinfo for mce.  Note that some older Pentium systems
 772           have a design flaw which leads to false MCE events - hence MCE is
 773           disabled on all P5 processors, unless explicitly enabled with "mce"
 774           as a boot argument.  Similarly, if MCE is built in and creates a
 775           problem on some new non-standard machine, you can boot with "nomce"
 776           to disable it.  MCE support simply ignores non-MCE processors like
 777           the 386 and 486, so nearly everyone can say Y here.
 778
 779 config X86_MCE_INTEL
 780         def_bool y
 781         prompt "Intel MCE features"
 782         depends on X86_64 && X86_MCE && X86_LOCAL_APIC
 783         ---help---
 784            Additional support for intel specific MCE features such as
 785            the thermal monitor.
 786
 787 config X86_MCE_AMD
 788         def_bool y
 789         prompt "AMD MCE features"
 790         depends on X86_64 && X86_MCE && X86_LOCAL_APIC
 791         ---help---
 792            Additional support for AMD specific MCE features such as
 793            the DRAM Error Threshold.
 794
 795 config X86_MCE_THRESHOLD
 796         depends on X86_MCE_AMD || X86_MCE_INTEL
 797         bool
 798         default y
 799
 800 config X86_MCE_NONFATAL
 801         tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
 802         depends on X86_32 && X86_MCE
 803         ---help---
 804           Enabling this feature starts a timer that triggers every 5 seconds which
 805           will look at the machine check registers to see if anything happened.
 806           Non-fatal problems automatically get corrected (but still logged).
 807           Disable this if you don't want to see these messages.
 808           Seeing the messages this option prints out may be indicative of dying
 809           or out-of-spec (ie, overclocked) hardware.
 810           This option only does something on certain CPUs.
 811           (AMD Athlon/Duron and Intel Pentium 4)
 812
 813 config X86_MCE_P4THERMAL
 814         bool "check for P4 thermal throttling interrupt."
 815         depends on X86_32 && X86_MCE && (X86_UP_APIC || SMP)
 816         ---help---
 817           Enabling this feature will cause a message to be printed when the P4
 818           enters thermal throttling.
 819
 820 config VM86
 821         bool "Enable VM86 support" if EMBEDDED
 822         default y
 823         depends on X86_32
 824         ---help---
 825           This option is required by programs like DOSEMU to run 16-bit legacy
 826           code on X86 processors. It also may be needed by software like
 827           XFree86 to initialize some video cards via BIOS. Disabling this
 828           option saves about 6k.
 829
 830 config TOSHIBA
 831         tristate "Toshiba Laptop support"
 832         depends on X86_32
 833         ---help---
 834           This adds a driver to safely access the System Management Mode of
 835           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 836           not work on models with a Phoenix BIOS. The System Management Mode
 837           is used to set the BIOS and power saving options on Toshiba portables.
 838
 839           For information on utilities to make use of this driver see the
 840           Toshiba Linux utilities web site at:
 841           <http://www.buzzard.org.uk/toshiba/>.
 842
 843           Say Y if you intend to run this kernel on a Toshiba portable.
 844           Say N otherwise.
 845
 846 config I8K
 847         tristate "Dell laptop support"
 848         ---help---
 849           This adds a driver to safely access the System Management Mode
 850           of the CPU on the Dell Inspiron 8000. The System Management Mode
 851           is used to read cpu temperature and cooling fan status and to
 852           control the fans on the I8K portables.
 853
 854           This driver has been tested only on the Inspiron 8000 but it may
 855           also work with other Dell laptops. You can force loading on other
 856           models by passing the parameter `force=1' to the module. Use at
 857           your own risk.
 858
 859           For information on utilities to make use of this driver see the
 860           I8K Linux utilities web site at:
 861           <http://people.debian.org/~dz/i8k/>
 862
 863           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 864           Say N otherwise.
 865
 866 config X86_REBOOTFIXUPS
 867         bool "Enable X86 board specific fixups for reboot"
 868         depends on X86_32
 869         ---help---
 870           This enables chipset and/or board specific fixups to be done
 871           in order to get reboot to work correctly. This is only needed on
 872           some combinations of hardware and BIOS. The symptom, for which
 873           this config is intended, is when reboot ends with a stalled/hung
 874           system.
 875
 876           Currently, the only fixup is for the Geode machines using
 877           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 878
 879           Say Y if you want to enable the fixup. Currently, it's safe to
 880           enable this option even if you don't need it.
 881           Say N otherwise.
 882
 883 config MICROCODE
 884         tristate "/dev/cpu/microcode - microcode support"
 885         select FW_LOADER
 886         ---help---
 887           If you say Y here, you will be able to update the microcode on
 888           certain Intel and AMD processors. The Intel support is for the
 889           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 890           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 891           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 892           You will obviously need the actual microcode binary data itself
 893           which is not shipped with the Linux kernel.
 894
 895           This option selects the general module only, you need to select
 896           at least one vendor specific module as well.
 897
 898           To compile this driver as a module, choose M here: the
 899           module will be called microcode.
 900
 901 config MICROCODE_INTEL
 902         bool "Intel microcode patch loading support"
 903         depends on MICROCODE
 904         default MICROCODE
 905         select FW_LOADER
 906         ---help---
 907           This options enables microcode patch loading support for Intel
 908           processors.
 909
 910           For latest news and information on obtaining all the required
 911           Intel ingredients for this driver, check:
 912           <http://www.urbanmyth.org/microcode/>.
 913
 914 config MICROCODE_AMD
 915         bool "AMD microcode patch loading support"
 916         depends on MICROCODE
 917         select FW_LOADER
 918         ---help---
 919           If you select this option, microcode patch loading support for AMD
 920           processors will be enabled.
 921
 922 config MICROCODE_OLD_INTERFACE
 923         def_bool y
 924         depends on MICROCODE
 925
 926 config X86_MSR
 927         tristate "/dev/cpu/*/msr - Model-specific register support"
 928         ---help---
 929           This device gives privileged processes access to the x86
 930           Model-Specific Registers (MSRs).  It is a character device with
 931           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
 932           MSR accesses are directed to a specific CPU on multi-processor
 933           systems.
 934
 935 config X86_CPUID
 936         tristate "/dev/cpu/*/cpuid - CPU information support"
 937         ---help---
 938           This device gives processes access to the x86 CPUID instruction to
 939           be executed on a specific processor.  It is a character device
 940           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
 941           /dev/cpu/31/cpuid.
 942
 943 config X86_CPU_DEBUG
 944         tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
 945         ---help---
 946           If you select this option, this will provide various x86 CPUs
 947           information through debugfs.
 948
 949 choice
 950         prompt "High Memory Support"
 951         default HIGHMEM4G if !X86_NUMAQ
 952         default HIGHMEM64G if X86_NUMAQ
 953         depends on X86_32
 954
 955 config NOHIGHMEM
 956         bool "off"
 957         depends on !X86_NUMAQ
 958         ---help---
 959           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
 960           However, the address space of 32-bit x86 processors is only 4
 961           Gigabytes large. That means that, if you have a large amount of
 962           physical memory, not all of it can be "permanently mapped" by the
 963           kernel. The physical memory that's not permanently mapped is called
 964           "high memory".
 965
 966           If you are compiling a kernel which will never run on a machine with
 967           more than 1 Gigabyte total physical RAM, answer "off" here (default
 968           choice and suitable for most users). This will result in a "3GB/1GB"
 969           split: 3GB are mapped so that each process sees a 3GB virtual memory
 970           space and the remaining part of the 4GB virtual memory space is used
 971           by the kernel to permanently map as much physical memory as
 972           possible.
 973
 974           If the machine has between 1 and 4 Gigabytes physical RAM, then
 975           answer "4GB" here.
 976
 977           If more than 4 Gigabytes is used then answer "64GB" here. This
 978           selection turns Intel PAE (Physical Address Extension) mode on.
 979           PAE implements 3-level paging on IA32 processors. PAE is fully
 980           supported by Linux, PAE mode is implemented on all recent Intel
 981           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
 982           then the kernel will not boot on CPUs that don't support PAE!
 983
 984           The actual amount of total physical memory will either be
 985           auto detected or can be forced by using a kernel command line option
 986           such as "mem=256M". (Try "man bootparam" or see the documentation of
 987           your boot loader (lilo or loadlin) about how to pass options to the
 988           kernel at boot time.)
 989
 990           If unsure, say "off".
 991
 992 config HIGHMEM4G
 993         bool "4GB"
 994         depends on !X86_NUMAQ
 995         ---help---
 996           Select this if you have a 32-bit processor and between 1 and 4
 997           gigabytes of physical RAM.
 998
 999 config HIGHMEM64G
1000         bool "64GB"
1001         depends on !M386 && !M486
1002         select X86_PAE
1003         ---help---
1004           Select this if you have a 32-bit processor and more than 4
1005           gigabytes of physical RAM.
1006
1007 endchoice
1008
1009 choice
1010         depends on EXPERIMENTAL
1011         prompt "Memory split" if EMBEDDED
1012         default VMSPLIT_3G
1013         depends on X86_32
1014         ---help---
1015           Select the desired split between kernel and user memory.
1016
1017           If the address range available to the kernel is less than the
1018           physical memory installed, the remaining memory will be available
1019           as "high memory". Accessing high memory is a little more costly
1020           than low memory, as it needs to be mapped into the kernel first.
1021           Note that increasing the kernel address space limits the range
1022           available to user programs, making the address space there
1023           tighter.  Selecting anything other than the default 3G/1G split
1024           will also likely make your kernel incompatible with binary-only
1025           kernel modules.
1026
1027           If you are not absolutely sure what you are doing, leave this
1028           option alone!
1029
1030         config VMSPLIT_3G
1031                 bool "3G/1G user/kernel split"
1032         config VMSPLIT_3G_OPT
1033                 depends on !X86_PAE
1034                 bool "3G/1G user/kernel split (for full 1G low memory)"
1035         config VMSPLIT_2G
1036                 bool "2G/2G user/kernel split"
1037         config VMSPLIT_2G_OPT
1038                 depends on !X86_PAE
1039                 bool "2G/2G user/kernel split (for full 2G low memory)"
1040         config VMSPLIT_1G
1041                 bool "1G/3G user/kernel split"
1042 endchoice
1043
1044 config PAGE_OFFSET
1045         hex
1046         default 0xB0000000 if VMSPLIT_3G_OPT
1047         default 0x80000000 if VMSPLIT_2G
1048         default 0x78000000 if VMSPLIT_2G_OPT
1049         default 0x40000000 if VMSPLIT_1G
1050         default 0xC0000000
1051         depends on X86_32
1052
1053 config HIGHMEM
1054         def_bool y
1055         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1056
1057 config X86_PAE
1058         bool "PAE (Physical Address Extension) Support"
1059         depends on X86_32 && !HIGHMEM4G
1060         ---help---
1061           PAE is required for NX support, and furthermore enables
1062           larger swapspace support for non-overcommit purposes. It
1063           has the cost of more pagetable lookup overhead, and also
1064           consumes more pagetable space per process.
1065
1066 config ARCH_PHYS_ADDR_T_64BIT
1067         def_bool X86_64 || X86_PAE
1068
1069 config DIRECT_GBPAGES
1070         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1071         default y
1072         depends on X86_64
1073         ---help---
1074           Allow the kernel linear mapping to use 1GB pages on CPUs that
1075           support it. This can improve the kernel's performance a tiny bit by
1076           reducing TLB pressure. If in doubt, say "Y".
1077
1078 # Common NUMA Features
1079 config NUMA
1080         bool "Numa Memory Allocation and Scheduler Support"
1081         depends on SMP
1082         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1083         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1084         ---help---
1085           Enable NUMA (Non Uniform Memory Access) support.
1086
1087           The kernel will try to allocate memory used by a CPU on the
1088           local memory controller of the CPU and add some more
1089           NUMA awareness to the kernel.
1090
1091           For 64-bit this is recommended if the system is Intel Core i7
1092           (or later), AMD Opteron, or EM64T NUMA.
1093
1094           For 32-bit this is only needed on (rare) 32-bit-only platforms
1095           that support NUMA topologies, such as NUMAQ / Summit, or if you
1096           boot a 32-bit kernel on a 64-bit NUMA platform.
1097
1098           Otherwise, you should say N.
1099
1100 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1101         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1102
1103 config K8_NUMA
1104         def_bool y
1105         prompt "Old style AMD Opteron NUMA detection"
1106         depends on X86_64 && NUMA && PCI
1107         ---help---
1108           Enable K8 NUMA node topology detection.  You should say Y here if
1109           you have a multi processor AMD K8 system. This uses an old
1110           method to read the NUMA configuration directly from the builtin
1111           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1112           instead, which also takes priority if both are compiled in.
1113
1114 config X86_64_ACPI_NUMA
1115         def_bool y
1116         prompt "ACPI NUMA detection"
1117         depends on X86_64 && NUMA && ACPI && PCI
1118         select ACPI_NUMA
1119         ---help---
1120           Enable ACPI SRAT based node topology detection.
1121
1122 # Some NUMA nodes have memory ranges that span
1123 # other nodes.  Even though a pfn is valid and
1124 # between a node's start and end pfns, it may not
1125 # reside on that node.  See memmap_init_zone()
1126 # for details.
1127 config NODES_SPAN_OTHER_NODES
1128         def_bool y
1129         depends on X86_64_ACPI_NUMA
1130
1131 config NUMA_EMU
1132         bool "NUMA emulation"
1133         depends on X86_64 && NUMA
1134         ---help---
1135           Enable NUMA emulation. A flat machine will be split
1136           into virtual nodes when booted with "numa=fake=N", where N is the
1137           number of nodes. This is only useful for debugging.
1138
1139 config NODES_SHIFT
1140         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1141         range 1 9
1142         default "9" if MAXSMP
1143         default "6" if X86_64
1144         default "4" if X86_NUMAQ
1145         default "3"
1146         depends on NEED_MULTIPLE_NODES
1147         ---help---
1148           Specify the maximum number of NUMA Nodes available on the target
1149           system.  Increases memory reserved to accommodate various tables.
1150
1151 config HAVE_ARCH_BOOTMEM
1152         def_bool y
1153         depends on X86_32 && NUMA
1154
1155 config ARCH_HAVE_MEMORY_PRESENT
1156         def_bool y
1157         depends on X86_32 && DISCONTIGMEM
1158
1159 config NEED_NODE_MEMMAP_SIZE
1160         def_bool y
1161         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1162
1163 config HAVE_ARCH_ALLOC_REMAP
1164         def_bool y
1165         depends on X86_32 && NUMA
1166
1167 config ARCH_FLATMEM_ENABLE
1168         def_bool y
1169         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1170
1171 config ARCH_DISCONTIGMEM_ENABLE
1172         def_bool y
1173         depends on NUMA && X86_32
1174
1175 config ARCH_DISCONTIGMEM_DEFAULT
1176         def_bool y
1177         depends on NUMA && X86_32
1178
1179 config ARCH_SPARSEMEM_DEFAULT
1180         def_bool y
1181         depends on X86_64
1182
1183 config ARCH_SPARSEMEM_ENABLE
1184         def_bool y
1185         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1186         select SPARSEMEM_STATIC if X86_32
1187         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1188
1189 config ARCH_SELECT_MEMORY_MODEL
1190         def_bool y
1191         depends on ARCH_SPARSEMEM_ENABLE
1192
1193 config ARCH_MEMORY_PROBE
1194         def_bool X86_64
1195         depends on MEMORY_HOTPLUG
1196
1197 source "mm/Kconfig"
1198
1199 config HIGHPTE
1200         bool "Allocate 3rd-level pagetables from highmem"
1201         depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1202         ---help---
1203           The VM uses one page table entry for each page of physical memory.
1204           For systems with a lot of RAM, this can be wasteful of precious
1205           low memory.  Setting this option will put user-space page table
1206           entries in high memory.
1207
1208 config X86_CHECK_BIOS_CORRUPTION
1209         bool "Check for low memory corruption"
1210         ---help---
1211           Periodically check for memory corruption in low memory, which
1212           is suspected to be caused by BIOS.  Even when enabled in the
1213           configuration, it is disabled at runtime.  Enable it by
1214           setting "memory_corruption_check=1" on the kernel command
1215           line.  By default it scans the low 64k of memory every 60
1216           seconds; see the memory_corruption_check_size and
1217           memory_corruption_check_period parameters in
1218           Documentation/kernel-parameters.txt to adjust this.
1219
1220           When enabled with the default parameters, this option has
1221           almost no overhead, as it reserves a relatively small amount
1222           of memory and scans it infrequently.  It both detects corruption
1223           and prevents it from affecting the running system.
1224
1225           It is, however, intended as a diagnostic tool; if repeatable
1226           BIOS-originated corruption always affects the same memory,
1227           you can use memmap= to prevent the kernel from using that
1228           memory.
1229
1230 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1231         bool "Set the default setting of memory_corruption_check"
1232         depends on X86_CHECK_BIOS_CORRUPTION
1233         default y
1234         ---help---
1235           Set whether the default state of memory_corruption_check is
1236           on or off.
1237
1238 config X86_RESERVE_LOW_64K
1239         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1240         default y
1241         ---help---
1242           Reserve the first 64K of physical RAM on BIOSes that are known
1243           to potentially corrupt that memory range. A numbers of BIOSes are
1244           known to utilize this area during suspend/resume, so it must not
1245           be used by the kernel.
1246
1247           Set this to N if you are absolutely sure that you trust the BIOS
1248           to get all its memory reservations and usages right.
1249
1250           If you have doubts about the BIOS (e.g. suspend/resume does not
1251           work or there's kernel crashes after certain hardware hotplug
1252           events) and it's not AMI or Phoenix, then you might want to enable
1253           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1254           corruption patterns.
1255
1256           Say Y if unsure.
1257
1258 config MATH_EMULATION
1259         bool
1260         prompt "Math emulation" if X86_32
1261         ---help---
1262           Linux can emulate a math coprocessor (used for floating point
1263           operations) if you don't have one. 486DX and Pentium processors have
1264           a math coprocessor built in, 486SX and 386 do not, unless you added
1265           a 487DX or 387, respectively. (The messages during boot time can
1266           give you some hints here ["man dmesg"].) Everyone needs either a
1267           coprocessor or this emulation.
1268
1269           If you don't have a math coprocessor, you need to say Y here; if you
1270           say Y here even though you have a coprocessor, the coprocessor will
1271           be used nevertheless. (This behavior can be changed with the kernel
1272           command line option "no387", which comes handy if your coprocessor
1273           is broken. Try "man bootparam" or see the documentation of your boot
1274           loader (lilo or loadlin) about how to pass options to the kernel at
1275           boot time.) This means that it is a good idea to say Y here if you
1276           intend to use this kernel on different machines.
1277
1278           More information about the internals of the Linux math coprocessor
1279           emulation can be found in <file:arch/x86/math-emu/README>.
1280
1281           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1282           kernel, it won't hurt.
1283
1284 config MTRR
1285         bool "MTRR (Memory Type Range Register) support"
1286         ---help---
1287           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1288           the Memory Type Range Registers (MTRRs) may be used to control
1289           processor access to memory ranges. This is most useful if you have
1290           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1291           allows bus write transfers to be combined into a larger transfer
1292           before bursting over the PCI/AGP bus. This can increase performance
1293           of image write operations 2.5 times or more. Saying Y here creates a
1294           /proc/mtrr file which may be used to manipulate your processor's
1295           MTRRs. Typically the X server should use this.
1296
1297           This code has a reasonably generic interface so that similar
1298           control registers on other processors can be easily supported
1299           as well:
1300
1301           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1302           Registers (ARRs) which provide a similar functionality to MTRRs. For
1303           these, the ARRs are used to emulate the MTRRs.
1304           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1305           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1306           write-combining. All of these processors are supported by this code
1307           and it makes sense to say Y here if you have one of them.
1308
1309           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1310           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1311           can lead to all sorts of problems, so it's good to say Y here.
1312
1313           You can safely say Y even if your machine doesn't have MTRRs, you'll
1314           just add about 9 KB to your kernel.
1315
1316           See <file:Documentation/x86/mtrr.txt> for more information.
1317
1318 config MTRR_SANITIZER
1319         def_bool y
1320         prompt "MTRR cleanup support"
1321         depends on MTRR
1322         ---help---
1323           Convert MTRR layout from continuous to discrete, so X drivers can
1324           add writeback entries.
1325
1326           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1327           The largest mtrr entry size for a continuous block can be set with
1328           mtrr_chunk_size.
1329
1330           If unsure, say Y.
1331
1332 config MTRR_SANITIZER_ENABLE_DEFAULT
1333         int "MTRR cleanup enable value (0-1)"
1334         range 0 1
1335         default "0"
1336         depends on MTRR_SANITIZER
1337         ---help---
1338           Enable mtrr cleanup default value
1339
1340 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1341         int "MTRR cleanup spare reg num (0-7)"
1342         range 0 7
1343         default "1"
1344         depends on MTRR_SANITIZER
1345         ---help---
1346           mtrr cleanup spare entries default, it can be changed via
1347           mtrr_spare_reg_nr=N on the kernel command line.
1348
1349 config X86_PAT
1350         bool
1351         prompt "x86 PAT support"
1352         depends on MTRR
1353         ---help---
1354           Use PAT attributes to setup page level cache control.
1355
1356           PATs are the modern equivalents of MTRRs and are much more
1357           flexible than MTRRs.
1358
1359           Say N here if you see bootup problems (boot crash, boot hang,
1360           spontaneous reboots) or a non-working video driver.
1361
1362           If unsure, say Y.
1363
1364 config EFI
1365         bool "EFI runtime service support"
1366         depends on ACPI
1367         ---help---
1368           This enables the kernel to use EFI runtime services that are
1369           available (such as the EFI variable services).
1370
1371           This option is only useful on systems that have EFI firmware.
1372           In addition, you should use the latest ELILO loader available
1373           at <http://elilo.sourceforge.net> in order to take advantage
1374           of EFI runtime services. However, even with this option, the
1375           resultant kernel should continue to boot on existing non-EFI
1376           platforms.
1377
1378 config SECCOMP
1379         def_bool y
1380         prompt "Enable seccomp to safely compute untrusted bytecode"
1381         ---help---
1382           This kernel feature is useful for number crunching applications
1383           that may need to compute untrusted bytecode during their
1384           execution. By using pipes or other transports made available to
1385           the process as file descriptors supporting the read/write
1386           syscalls, it's possible to isolate those applications in
1387           their own address space using seccomp. Once seccomp is
1388           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1389           and the task is only allowed to execute a few safe syscalls
1390           defined by each seccomp mode.
1391
1392           If unsure, say Y. Only embedded should say N here.
1393
1394 config CC_STACKPROTECTOR_ALL
1395         bool
1396
1397 config CC_STACKPROTECTOR
1398         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1399         select CC_STACKPROTECTOR_ALL
1400         ---help---
1401           This option turns on the -fstack-protector GCC feature. This
1402           feature puts, at the beginning of functions, a canary value on
1403           the stack just before the return address, and validates
1404           the value just before actually returning.  Stack based buffer
1405           overflows (that need to overwrite this return address) now also
1406           overwrite the canary, which gets detected and the attack is then
1407           neutralized via a kernel panic.
1408
1409           This feature requires gcc version 4.2 or above, or a distribution
1410           gcc with the feature backported. Older versions are automatically
1411           detected and for those versions, this configuration option is
1412           ignored. (and a warning is printed during bootup)
1413
1414 source kernel/Kconfig.hz
1415
1416 config KEXEC
1417         bool "kexec system call"
1418         ---help---
1419           kexec is a system call that implements the ability to shutdown your
1420           current kernel, and to start another kernel.  It is like a reboot
1421           but it is independent of the system firmware.   And like a reboot
1422           you can start any kernel with it, not just Linux.
1423
1424           The name comes from the similarity to the exec system call.
1425
1426           It is an ongoing process to be certain the hardware in a machine
1427           is properly shutdown, so do not be surprised if this code does not
1428           initially work for you.  It may help to enable device hotplugging
1429           support.  As of this writing the exact hardware interface is
1430           strongly in flux, so no good recommendation can be made.
1431
1432 config CRASH_DUMP
1433         bool "kernel crash dumps"
1434         depends on X86_64 || (X86_32 && HIGHMEM)
1435         ---help---
1436           Generate crash dump after being started by kexec.
1437           This should be normally only set in special crash dump kernels
1438           which are loaded in the main kernel with kexec-tools into
1439           a specially reserved region and then later executed after
1440           a crash by kdump/kexec. The crash dump kernel must be compiled
1441           to a memory address not used by the main kernel or BIOS using
1442           PHYSICAL_START, or it must be built as a relocatable image
1443           (CONFIG_RELOCATABLE=y).
1444           For more details see Documentation/kdump/kdump.txt
1445
1446 config KEXEC_JUMP
1447         bool "kexec jump (EXPERIMENTAL)"
1448         depends on EXPERIMENTAL
1449         depends on KEXEC && HIBERNATION
1450         ---help---
1451           Jump between original kernel and kexeced kernel and invoke
1452           code in physical address mode via KEXEC
1453
1454 config PHYSICAL_START
1455         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1456         default "0x1000000" if X86_NUMAQ
1457         default "0x200000" if X86_64
1458         default "0x100000"
1459         ---help---
1460           This gives the physical address where the kernel is loaded.
1461
1462           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1463           bzImage will decompress itself to above physical address and
1464           run from there. Otherwise, bzImage will run from the address where
1465           it has been loaded by the boot loader and will ignore above physical
1466           address.
1467
1468           In normal kdump cases one does not have to set/change this option
1469           as now bzImage can be compiled as a completely relocatable image
1470           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1471           address. This option is mainly useful for the folks who don't want
1472           to use a bzImage for capturing the crash dump and want to use a
1473           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1474           to be specifically compiled to run from a specific memory area
1475           (normally a reserved region) and this option comes handy.
1476
1477           So if you are using bzImage for capturing the crash dump, leave
1478           the value here unchanged to 0x100000 and set CONFIG_RELOCATABLE=y.
1479           Otherwise if you plan to use vmlinux for capturing the crash dump
1480           change this value to start of the reserved region (Typically 16MB
1481           0x1000000). In other words, it can be set based on the "X" value as
1482           specified in the "crashkernel=YM@XM" command line boot parameter
1483           passed to the panic-ed kernel. Typically this parameter is set as
1484           crashkernel=64M@16M. Please take a look at
1485           Documentation/kdump/kdump.txt for more details about crash dumps.
1486
1487           Usage of bzImage for capturing the crash dump is recommended as
1488           one does not have to build two kernels. Same kernel can be used
1489           as production kernel and capture kernel. Above option should have
1490           gone away after relocatable bzImage support is introduced. But it
1491           is present because there are users out there who continue to use
1492           vmlinux for dump capture. This option should go away down the
1493           line.
1494
1495           Don't change this unless you know what you are doing.
1496
1497 config RELOCATABLE
1498         bool "Build a relocatable kernel (EXPERIMENTAL)"
1499         depends on EXPERIMENTAL
1500         ---help---
1501           This builds a kernel image that retains relocation information
1502           so it can be loaded someplace besides the default 1MB.
1503           The relocations tend to make the kernel binary about 10% larger,
1504           but are discarded at runtime.
1505
1506           One use is for the kexec on panic case where the recovery kernel
1507           must live at a different physical address than the primary
1508           kernel.
1509
1510           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1511           it has been loaded at and the compile time physical address
1512           (CONFIG_PHYSICAL_START) is ignored.
1513
1514 config PHYSICAL_ALIGN
1515         hex
1516         prompt "Alignment value to which kernel should be aligned" if X86_32
1517         default "0x100000" if X86_32
1518         default "0x200000" if X86_64
1519         range 0x2000 0x400000
1520         ---help---
1521           This value puts the alignment restrictions on physical address
1522           where kernel is loaded and run from. Kernel is compiled for an
1523           address which meets above alignment restriction.
1524
1525           If bootloader loads the kernel at a non-aligned address and
1526           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1527           address aligned to above value and run from there.
1528
1529           If bootloader loads the kernel at a non-aligned address and
1530           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1531           load address and decompress itself to the address it has been
1532           compiled for and run from there. The address for which kernel is
1533           compiled already meets above alignment restrictions. Hence the
1534           end result is that kernel runs from a physical address meeting
1535           above alignment restrictions.
1536
1537           Don't change this unless you know what you are doing.
1538
1539 config HOTPLUG_CPU
1540         bool "Support for hot-pluggable CPUs"
1541         depends on SMP && HOTPLUG
1542         ---help---
1543           Say Y here to allow turning CPUs off and on. CPUs can be
1544           controlled through /sys/devices/system/cpu.
1545           ( Note: power management support will enable this option
1546             automatically on SMP systems. )
1547           Say N if you want to disable CPU hotplug.
1548
1549 config COMPAT_VDSO
1550         def_bool y
1551         prompt "Compat VDSO support"
1552         depends on X86_32 || IA32_EMULATION
1553         ---help---
1554           Map the 32-bit VDSO to the predictable old-style address too.
1555         ---help---
1556           Say N here if you are running a sufficiently recent glibc
1557           version (2.3.3 or later), to remove the high-mapped
1558           VDSO mapping and to exclusively use the randomized VDSO.
1559
1560           If unsure, say Y.
1561
1562 config CMDLINE_BOOL
1563         bool "Built-in kernel command line"
1564         default n
1565         ---help---
1566           Allow for specifying boot arguments to the kernel at
1567           build time.  On some systems (e.g. embedded ones), it is
1568           necessary or convenient to provide some or all of the
1569           kernel boot arguments with the kernel itself (that is,
1570           to not rely on the boot loader to provide them.)
1571
1572           To compile command line arguments into the kernel,
1573           set this option to 'Y', then fill in the
1574           the boot arguments in CONFIG_CMDLINE.
1575
1576           Systems with fully functional boot loaders (i.e. non-embedded)
1577           should leave this option set to 'N'.
1578
1579 config CMDLINE
1580         string "Built-in kernel command string"
1581         depends on CMDLINE_BOOL
1582         default ""
1583         ---help---
1584           Enter arguments here that should be compiled into the kernel
1585           image and used at boot time.  If the boot loader provides a
1586           command line at boot time, it is appended to this string to
1587           form the full kernel command line, when the system boots.
1588
1589           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1590           change this behavior.
1591
1592           In most cases, the command line (whether built-in or provided
1593           by the boot loader) should specify the device for the root
1594           file system.
1595
1596 config CMDLINE_OVERRIDE
1597         bool "Built-in command line overrides boot loader arguments"
1598         default n
1599         depends on CMDLINE_BOOL
1600         ---help---
1601           Set this option to 'Y' to have the kernel ignore the boot loader
1602           command line, and use ONLY the built-in command line.
1603
1604           This is used to work around broken boot loaders.  This should
1605           be set to 'N' under normal conditions.
1606
1607 endmenu
1608
1609 config ARCH_ENABLE_MEMORY_HOTPLUG
1610         def_bool y
1611         depends on X86_64 || (X86_32 && HIGHMEM)
1612
1613 config ARCH_ENABLE_MEMORY_HOTREMOVE
1614         def_bool y
1615         depends on MEMORY_HOTPLUG
1616
1617 config HAVE_ARCH_EARLY_PFN_TO_NID
1618         def_bool X86_64
1619         depends on NUMA
1620
1621 menu "Power management and ACPI options"
1622
1623 config ARCH_HIBERNATION_HEADER
1624         def_bool y
1625         depends on X86_64 && HIBERNATION
1626
1627 source "kernel/power/Kconfig"
1628
1629 source "drivers/acpi/Kconfig"
1630
1631 config X86_APM_BOOT
1632         bool
1633         default y
1634         depends on APM || APM_MODULE
1635
1636 menuconfig APM
1637         tristate "APM (Advanced Power Management) BIOS support"
1638         depends on X86_32 && PM_SLEEP
1639         ---help---
1640           APM is a BIOS specification for saving power using several different
1641           techniques. This is mostly useful for battery powered laptops with
1642           APM compliant BIOSes. If you say Y here, the system time will be
1643           reset after a RESUME operation, the /proc/apm device will provide
1644           battery status information, and user-space programs will receive
1645           notification of APM "events" (e.g. battery status change).
1646
1647           If you select "Y" here, you can disable actual use of the APM
1648           BIOS by passing the "apm=off" option to the kernel at boot time.
1649
1650           Note that the APM support is almost completely disabled for
1651           machines with more than one CPU.
1652
1653           In order to use APM, you will need supporting software. For location
1654           and more information, read <file:Documentation/power/pm.txt> and the
1655           Battery Powered Linux mini-HOWTO, available from
1656           <http://www.tldp.org/docs.html#howto>.
1657
1658           This driver does not spin down disk drives (see the hdparm(8)
1659           manpage ("man 8 hdparm") for that), and it doesn't turn off
1660           VESA-compliant "green" monitors.
1661
1662           This driver does not support the TI 4000M TravelMate and the ACER
1663           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1664           desktop machines also don't have compliant BIOSes, and this driver
1665           may cause those machines to panic during the boot phase.
1666
1667           Generally, if you don't have a battery in your machine, there isn't
1668           much point in using this driver and you should say N. If you get
1669           random kernel OOPSes or reboots that don't seem to be related to
1670           anything, try disabling/enabling this option (or disabling/enabling
1671           APM in your BIOS).
1672
1673           Some other things you should try when experiencing seemingly random,
1674           "weird" problems:
1675
1676           1) make sure that you have enough swap space and that it is
1677           enabled.
1678           2) pass the "no-hlt" option to the kernel
1679           3) switch on floating point emulation in the kernel and pass
1680           the "no387" option to the kernel
1681           4) pass the "floppy=nodma" option to the kernel
1682           5) pass the "mem=4M" option to the kernel (thereby disabling
1683           all but the first 4 MB of RAM)
1684           6) make sure that the CPU is not over clocked.
1685           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1686           8) disable the cache from your BIOS settings
1687           9) install a fan for the video card or exchange video RAM
1688           10) install a better fan for the CPU
1689           11) exchange RAM chips
1690           12) exchange the motherboard.
1691
1692           To compile this driver as a module, choose M here: the
1693           module will be called apm.
1694
1695 if APM
1696
1697 config APM_IGNORE_USER_SUSPEND
1698         bool "Ignore USER SUSPEND"
1699         ---help---
1700           This option will ignore USER SUSPEND requests. On machines with a
1701           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1702           series notebooks, it is necessary to say Y because of a BIOS bug.
1703
1704 config APM_DO_ENABLE
1705         bool "Enable PM at boot time"
1706         ---help---
1707           Enable APM features at boot time. From page 36 of the APM BIOS
1708           specification: "When disabled, the APM BIOS does not automatically
1709           power manage devices, enter the Standby State, enter the Suspend
1710           State, or take power saving steps in response to CPU Idle calls."
1711           This driver will make CPU Idle calls when Linux is idle (unless this
1712           feature is turned off -- see "Do CPU IDLE calls", below). This
1713           should always save battery power, but more complicated APM features
1714           will be dependent on your BIOS implementation. You may need to turn
1715           this option off if your computer hangs at boot time when using APM
1716           support, or if it beeps continuously instead of suspending. Turn
1717           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1718           T400CDT. This is off by default since most machines do fine without
1719           this feature.
1720
1721 config APM_CPU_IDLE
1722         bool "Make CPU Idle calls when idle"
1723         ---help---
1724           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1725           On some machines, this can activate improved power savings, such as
1726           a slowed CPU clock rate, when the machine is idle. These idle calls
1727           are made after the idle loop has run for some length of time (e.g.,
1728           333 mS). On some machines, this will cause a hang at boot time or
1729           whenever the CPU becomes idle. (On machines with more than one CPU,
1730           this option does nothing.)
1731
1732 config APM_DISPLAY_BLANK
1733         bool "Enable console blanking using APM"
1734         ---help---
1735           Enable console blanking using the APM. Some laptops can use this to
1736           turn off the LCD backlight when the screen blanker of the Linux
1737           virtual console blanks the screen. Note that this is only used by
1738           the virtual console screen blanker, and won't turn off the backlight
1739           when using the X Window system. This also doesn't have anything to
1740           do with your VESA-compliant power-saving monitor. Further, this
1741           option doesn't work for all laptops -- it might not turn off your
1742           backlight at all, or it might print a lot of errors to the console,
1743           especially if you are using gpm.
1744
1745 config APM_ALLOW_INTS
1746         bool "Allow interrupts during APM BIOS calls"
1747         ---help---
1748           Normally we disable external interrupts while we are making calls to
1749           the APM BIOS as a measure to lessen the effects of a badly behaving
1750           BIOS implementation.  The BIOS should reenable interrupts if it
1751           needs to.  Unfortunately, some BIOSes do not -- especially those in
1752           many of the newer IBM Thinkpads.  If you experience hangs when you
1753           suspend, try setting this to Y.  Otherwise, say N.
1754
1755 endif # APM
1756
1757 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1758
1759 source "drivers/cpuidle/Kconfig"
1760
1761 source "drivers/idle/Kconfig"
1762
1763 endmenu
1764
1765
1766 menu "Bus options (PCI etc.)"
1767
1768 config PCI
1769         bool "PCI support"
1770         default y
1771         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1772         ---help---
1773           Find out whether you have a PCI motherboard. PCI is the name of a
1774           bus system, i.e. the way the CPU talks to the other stuff inside
1775           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1776           VESA. If you have PCI, say Y, otherwise N.
1777
1778 choice
1779         prompt "PCI access mode"
1780         depends on X86_32 && PCI
1781         default PCI_GOANY
1782         ---help---
1783           On PCI systems, the BIOS can be used to detect the PCI devices and
1784           determine their configuration. However, some old PCI motherboards
1785           have BIOS bugs and may crash if this is done. Also, some embedded
1786           PCI-based systems don't have any BIOS at all. Linux can also try to
1787           detect the PCI hardware directly without using the BIOS.
1788
1789           With this option, you can specify how Linux should detect the
1790           PCI devices. If you choose "BIOS", the BIOS will be used,
1791           if you choose "Direct", the BIOS won't be used, and if you
1792           choose "MMConfig", then PCI Express MMCONFIG will be used.
1793           If you choose "Any", the kernel will try MMCONFIG, then the
1794           direct access method and falls back to the BIOS if that doesn't
1795           work. If unsure, go with the default, which is "Any".
1796
1797 config PCI_GOBIOS
1798         bool "BIOS"
1799
1800 config PCI_GOMMCONFIG
1801         bool "MMConfig"
1802
1803 config PCI_GODIRECT
1804         bool "Direct"
1805
1806 config PCI_GOOLPC
1807         bool "OLPC"
1808         depends on OLPC
1809
1810 config PCI_GOANY
1811         bool "Any"
1812
1813 endchoice
1814
1815 config PCI_BIOS
1816         def_bool y
1817         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1818
1819 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1820 config PCI_DIRECT
1821         def_bool y
1822         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1823
1824 config PCI_MMCONFIG
1825         def_bool y
1826         depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1827
1828 config PCI_OLPC
1829         def_bool y
1830         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1831
1832 config PCI_DOMAINS
1833         def_bool y
1834         depends on PCI
1835
1836 config PCI_MMCONFIG
1837         bool "Support mmconfig PCI config space access"
1838         depends on X86_64 && PCI && ACPI
1839
1840 config DMAR
1841         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1842         depends on PCI_MSI && ACPI && EXPERIMENTAL
1843         help
1844           DMA remapping (DMAR) devices support enables independent address
1845           translations for Direct Memory Access (DMA) from devices.
1846           These DMA remapping devices are reported via ACPI tables
1847           and include PCI device scope covered by these DMA
1848           remapping devices.
1849
1850 config DMAR_DEFAULT_ON
1851         def_bool y
1852         prompt "Enable DMA Remapping Devices by default"
1853         depends on DMAR
1854         help
1855           Selecting this option will enable a DMAR device at boot time if
1856           one is found. If this option is not selected, DMAR support can
1857           be enabled by passing intel_iommu=on to the kernel. It is
1858           recommended you say N here while the DMAR code remains
1859           experimental.
1860
1861 config DMAR_GFX_WA
1862         def_bool y
1863         prompt "Support for Graphics workaround"
1864         depends on DMAR
1865         ---help---
1866           Current Graphics drivers tend to use physical address
1867           for DMA and avoid using DMA APIs. Setting this config
1868           option permits the IOMMU driver to set a unity map for
1869           all the OS-visible memory. Hence the driver can continue
1870           to use physical addresses for DMA.
1871
1872 config DMAR_FLOPPY_WA
1873         def_bool y
1874         depends on DMAR
1875         ---help---
1876           Floppy disk drivers are know to bypass DMA API calls
1877           thereby failing to work when IOMMU is enabled. This
1878           workaround will setup a 1:1 mapping for the first
1879           16M to make floppy (an ISA device) work.
1880
1881 config INTR_REMAP
1882         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1883         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1884         ---help---
1885           Supports Interrupt remapping for IO-APIC and MSI devices.
1886           To use x2apic mode in the CPU's which support x2APIC enhancements or
1887           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1888
1889 source "drivers/pci/pcie/Kconfig"
1890
1891 source "drivers/pci/Kconfig"
1892
1893 # x86_64 have no ISA slots, but do have ISA-style DMA.
1894 config ISA_DMA_API
1895         def_bool y
1896
1897 if X86_32
1898
1899 config ISA
1900         bool "ISA support"
1901         ---help---
1902           Find out whether you have ISA slots on your motherboard.  ISA is the
1903           name of a bus system, i.e. the way the CPU talks to the other stuff
1904           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1905           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1906           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1907
1908 config EISA
1909         bool "EISA support"
1910         depends on ISA
1911         ---help---
1912           The Extended Industry Standard Architecture (EISA) bus was
1913           developed as an open alternative to the IBM MicroChannel bus.
1914
1915           The EISA bus provided some of the features of the IBM MicroChannel
1916           bus while maintaining backward compatibility with cards made for
1917           the older ISA bus.  The EISA bus saw limited use between 1988 and
1918           1995 when it was made obsolete by the PCI bus.
1919
1920           Say Y here if you are building a kernel for an EISA-based machine.
1921
1922           Otherwise, say N.
1923
1924 source "drivers/eisa/Kconfig"
1925
1926 config MCA
1927         bool "MCA support"
1928         ---help---
1929           MicroChannel Architecture is found in some IBM PS/2 machines and
1930           laptops.  It is a bus system similar to PCI or ISA. See
1931           <file:Documentation/mca.txt> (and especially the web page given
1932           there) before attempting to build an MCA bus kernel.
1933
1934 source "drivers/mca/Kconfig"
1935
1936 config SCx200
1937         tristate "NatSemi SCx200 support"
1938         ---help---
1939           This provides basic support for National Semiconductor's
1940           (now AMD's) Geode processors.  The driver probes for the
1941           PCI-IDs of several on-chip devices, so its a good dependency
1942           for other scx200_* drivers.
1943
1944           If compiled as a module, the driver is named scx200.
1945
1946 config SCx200HR_TIMER
1947         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
1948         depends on SCx200 && GENERIC_TIME
1949         default y
1950         ---help---
1951           This driver provides a clocksource built upon the on-chip
1952           27MHz high-resolution timer.  Its also a workaround for
1953           NSC Geode SC-1100's buggy TSC, which loses time when the
1954           processor goes idle (as is done by the scheduler).  The
1955           other workaround is idle=poll boot option.
1956
1957 config GEODE_MFGPT_TIMER
1958         def_bool y
1959         prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
1960         depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
1961         ---help---
1962           This driver provides a clock event source based on the MFGPT
1963           timer(s) in the CS5535 and CS5536 companion chip for the geode.
1964           MFGPTs have a better resolution and max interval than the
1965           generic PIT, and are suitable for use as high-res timers.
1966
1967 config OLPC
1968         bool "One Laptop Per Child support"
1969         default n
1970         ---help---
1971           Add support for detecting the unique features of the OLPC
1972           XO hardware.
1973
1974 endif # X86_32
1975
1976 config K8_NB
1977         def_bool y
1978         depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
1979
1980 source "drivers/pcmcia/Kconfig"
1981
1982 source "drivers/pci/hotplug/Kconfig"
1983
1984 endmenu
1985
1986
1987 menu "Executable file formats / Emulations"
1988
1989 source "fs/Kconfig.binfmt"
1990
1991 config IA32_EMULATION
1992         bool "IA32 Emulation"
1993         depends on X86_64
1994         select COMPAT_BINFMT_ELF
1995         ---help---
1996           Include code to run 32-bit programs under a 64-bit kernel. You should
1997           likely turn this on, unless you're 100% sure that you don't have any
1998           32-bit programs left.
1999
2000 config IA32_AOUT
2001         tristate "IA32 a.out support"
2002         depends on IA32_EMULATION
2003         ---help---
2004           Support old a.out binaries in the 32bit emulation.
2005
2006 config COMPAT
2007         def_bool y
2008         depends on IA32_EMULATION
2009
2010 config COMPAT_FOR_U64_ALIGNMENT
2011         def_bool COMPAT
2012         depends on X86_64
2013
2014 config SYSVIPC_COMPAT
2015         def_bool y
2016         depends on COMPAT && SYSVIPC
2017
2018 endmenu
2019
2020
2021 config HAVE_ATOMIC_IOMAP
2022         def_bool y
2023         depends on X86_32
2024
2025 source "net/Kconfig"
2026
2027 source "drivers/Kconfig"
2028
2029 source "drivers/firmware/Kconfig"
2030
2031 source "fs/Kconfig"
2032
2033 source "arch/x86/Kconfig.debug"
2034
2035 source "security/Kconfig"
2036
2037 source "crypto/Kconfig"
2038
2039 source "arch/x86/kvm/Kconfig"
2040
2041 source "lib/Kconfig"