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