arch/x86/Kconfig

   1 # x86 configuration
   2 mainmenu "Linux Kernel Configuration for x86"
   3
   4 # Select 32 or 64 bit
   5 config 64BIT
   6         bool "64-bit kernel" if ARCH = "x86"
   7         default ARCH = "x86_64"
   8         ---help---
   9           Say yes to build a 64-bit kernel - formerly known as x86_64
  10           Say no to build a 32-bit kernel - formerly known as i386
  11
  12 config X86_32
  13         def_bool !64BIT
  14
  15 config X86_64
  16         def_bool 64BIT
  17
  18 ### Arch settings
  19 config X86
  20         def_bool y
  21         select HAVE_AOUT if X86_32
  22         select HAVE_READQ
  23         select HAVE_WRITEQ
  24         select HAVE_UNSTABLE_SCHED_CLOCK
  25         select HAVE_IDE
  26         select HAVE_OPROFILE
  27         select HAVE_PERF_COUNTERS if (!M386 && !M486)
  28         select HAVE_IOREMAP_PROT
  29         select HAVE_KPROBES
  30         select ARCH_WANT_OPTIONAL_GPIOLIB
  31         select ARCH_WANT_FRAME_POINTERS
  32         select HAVE_DMA_ATTRS
  33         select HAVE_KRETPROBES
  34         select HAVE_FTRACE_MCOUNT_RECORD
  35         select HAVE_DYNAMIC_FTRACE
  36         select HAVE_FUNCTION_TRACER
  37         select HAVE_FUNCTION_GRAPH_TRACER
  38         select HAVE_FUNCTION_GRAPH_FP_TEST
  39         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  40         select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  41         select HAVE_FTRACE_SYSCALLS
  42         select HAVE_KVM
  43         select HAVE_ARCH_KGDB
  44         select HAVE_ARCH_TRACEHOOK
  45         select HAVE_GENERIC_DMA_COHERENT if X86_32
  46         select HAVE_EFFICIENT_UNALIGNED_ACCESS
  47         select USER_STACKTRACE_SUPPORT
  48         select HAVE_DMA_API_DEBUG
  49         select HAVE_KERNEL_GZIP
  50         select HAVE_KERNEL_BZIP2
  51         select HAVE_KERNEL_LZMA
  52         select HAVE_ARCH_KMEMCHECK
  53
  54 config OUTPUT_FORMAT
  55         string
  56         default "elf32-i386" if X86_32
  57         default "elf64-x86-64" if X86_64
  58
  59 config ARCH_DEFCONFIG
  60         string
  61         default "arch/x86/configs/i386_defconfig" if X86_32
  62         default "arch/x86/configs/x86_64_defconfig" if X86_64
  63
  64 config GENERIC_TIME
  65         def_bool y
  66
  67 config GENERIC_CMOS_UPDATE
  68         def_bool y
  69
  70 config CLOCKSOURCE_WATCHDOG
  71         def_bool y
  72
  73 config GENERIC_CLOCKEVENTS
  74         def_bool y
  75
  76 config GENERIC_CLOCKEVENTS_BROADCAST
  77         def_bool y
  78         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  79
  80 config LOCKDEP_SUPPORT
  81         def_bool y
  82
  83 config STACKTRACE_SUPPORT
  84         def_bool y
  85
  86 config HAVE_LATENCYTOP_SUPPORT
  87         def_bool y
  88
  89 config FAST_CMPXCHG_LOCAL
  90         bool
  91         default y
  92
  93 config MMU
  94         def_bool y
  95
  96 config ZONE_DMA
  97         def_bool y
  98
  99 config SBUS
 100         bool
 101
 102 config GENERIC_ISA_DMA
 103         def_bool y
 104
 105 config GENERIC_IOMAP
 106         def_bool y
 107
 108 config GENERIC_BUG
 109         def_bool y
 110         depends on BUG
 111         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 112
 113 config GENERIC_BUG_RELATIVE_POINTERS
 114         bool
 115
 116 config GENERIC_HWEIGHT
 117         def_bool y
 118
 119 config GENERIC_GPIO
 120         bool
 121
 122 config ARCH_MAY_HAVE_PC_FDC
 123         def_bool y
 124
 125 config RWSEM_GENERIC_SPINLOCK
 126         def_bool !X86_XADD
 127
 128 config RWSEM_XCHGADD_ALGORITHM
 129         def_bool X86_XADD
 130
 131 config ARCH_HAS_CPU_IDLE_WAIT
 132         def_bool y
 133
 134 config GENERIC_CALIBRATE_DELAY
 135         def_bool y
 136
 137 config GENERIC_TIME_VSYSCALL
 138         bool
 139         default X86_64
 140
 141 config ARCH_HAS_CPU_RELAX
 142         def_bool y
 143
 144 config ARCH_HAS_DEFAULT_IDLE
 145         def_bool y
 146
 147 config ARCH_HAS_CACHE_LINE_SIZE
 148         def_bool y
 149
 150 config HAVE_SETUP_PER_CPU_AREA
 151         def_bool y
 152
 153 config HAVE_DYNAMIC_PER_CPU_AREA
 154         def_bool y
 155
 156 config HAVE_CPUMASK_OF_CPU_MAP
 157         def_bool X86_64_SMP
 158
 159 config ARCH_HIBERNATION_POSSIBLE
 160         def_bool y
 161
 162 config ARCH_SUSPEND_POSSIBLE
 163         def_bool y
 164
 165 config ZONE_DMA32
 166         bool
 167         default X86_64
 168
 169 config ARCH_POPULATES_NODE_MAP
 170         def_bool y
 171
 172 config AUDIT_ARCH
 173         bool
 174         default X86_64
 175
 176 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 177         def_bool y
 178
 179 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 180         def_bool y
 181
 182 config HAVE_INTEL_TXT
 183         def_bool y
 184         depends on EXPERIMENTAL && DMAR && ACPI
 185
 186 # Use the generic interrupt handling code in kernel/irq/:
 187 config GENERIC_HARDIRQS
 188         bool
 189         default y
 190
 191 config GENERIC_HARDIRQS_NO__DO_IRQ
 192        def_bool y
 193
 194 config GENERIC_IRQ_PROBE
 195         bool
 196         default y
 197
 198 config GENERIC_PENDING_IRQ
 199         bool
 200         depends on GENERIC_HARDIRQS && SMP
 201         default y
 202
 203 config USE_GENERIC_SMP_HELPERS
 204         def_bool y
 205         depends on SMP
 206
 207 config X86_32_SMP
 208         def_bool y
 209         depends on X86_32 && SMP
 210
 211 config X86_64_SMP
 212         def_bool y
 213         depends on X86_64 && SMP
 214
 215 config X86_HT
 216         bool
 217         depends on SMP
 218         default y
 219
 220 config X86_TRAMPOLINE
 221         bool
 222         depends on SMP || (64BIT && ACPI_SLEEP)
 223         default y
 224
 225 config X86_32_LAZY_GS
 226         def_bool y
 227         depends on X86_32 && !CC_STACKPROTECTOR
 228
 229 config KTIME_SCALAR
 230         def_bool X86_32
 231 source "init/Kconfig"
 232 source "kernel/Kconfig.freezer"
 233
 234 menu "Processor type and features"
 235
 236 source "kernel/time/Kconfig"
 237
 238 config SMP
 239         bool "Symmetric multi-processing support"
 240         ---help---
 241           This enables support for systems with more than one CPU. If you have
 242           a system with only one CPU, like most personal computers, say N. If
 243           you have a system with more than one CPU, say Y.
 244
 245           If you say N here, the kernel will run on single and multiprocessor
 246           machines, but will use only one CPU of a multiprocessor machine. If
 247           you say Y here, the kernel will run on many, but not all,
 248           singleprocessor machines. On a singleprocessor machine, the kernel
 249           will run faster if you say N here.
 250
 251           Note that if you say Y here and choose architecture "586" or
 252           "Pentium" under "Processor family", the kernel will not work on 486
 253           architectures. Similarly, multiprocessor kernels for the "PPro"
 254           architecture may not work on all Pentium based boards.
 255
 256           People using multiprocessor machines who say Y here should also say
 257           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 258           Management" code will be disabled if you say Y here.
 259
 260           See also <file:Documentation/i386/IO-APIC.txt>,
 261           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 262           <http://www.tldp.org/docs.html#howto>.
 263
 264           If you don't know what to do here, say N.
 265
 266 config X86_X2APIC
 267         bool "Support x2apic"
 268         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 269         ---help---
 270           This enables x2apic support on CPUs that have this feature.
 271
 272           This allows 32-bit apic IDs (so it can support very large systems),
 273           and accesses the local apic via MSRs not via mmio.
 274
 275           If you don't know what to do here, say N.
 276
 277 config SPARSE_IRQ
 278         bool "Support sparse irq numbering"
 279         depends on PCI_MSI || HT_IRQ
 280         ---help---
 281           This enables support for sparse irqs. This is useful for distro
 282           kernels that want to define a high CONFIG_NR_CPUS value but still
 283           want to have low kernel memory footprint on smaller machines.
 284
 285           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 286             out the irq_desc[] array in a more NUMA-friendly way. )
 287
 288           If you don't know what to do here, say N.
 289
 290 config NUMA_IRQ_DESC
 291         def_bool y
 292         depends on SPARSE_IRQ && NUMA
 293
 294 config X86_MPPARSE
 295         bool "Enable MPS table" if ACPI
 296         default y
 297         depends on X86_LOCAL_APIC
 298         ---help---
 299           For old smp systems that do not have proper acpi support. Newer systems
 300           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 301
 302 config X86_BIGSMP
 303         bool "Support for big SMP systems with more than 8 CPUs"
 304         depends on X86_32 && SMP
 305         ---help---
 306           This option is needed for the systems that have more than 8 CPUs
 307
 308 if X86_32
 309 config X86_EXTENDED_PLATFORM
 310         bool "Support for extended (non-PC) x86 platforms"
 311         default y
 312         ---help---
 313           If you disable this option then the kernel will only support
 314           standard PC platforms. (which covers the vast majority of
 315           systems out there.)
 316
 317           If you enable this option then you'll be able to select support
 318           for the following (non-PC) 32 bit x86 platforms:
 319                 AMD Elan
 320                 NUMAQ (IBM/Sequent)
 321                 RDC R-321x SoC
 322                 SGI 320/540 (Visual Workstation)
 323                 Summit/EXA (IBM x440)
 324                 Unisys ES7000 IA32 series
 325
 326           If you have one of these systems, or if you want to build a
 327           generic distribution kernel, say Y here - otherwise say N.
 328 endif
 329
 330 if X86_64
 331 config X86_EXTENDED_PLATFORM
 332         bool "Support for extended (non-PC) x86 platforms"
 333         default y
 334         ---help---
 335           If you disable this option then the kernel will only support
 336           standard PC platforms. (which covers the vast majority of
 337           systems out there.)
 338
 339           If you enable this option then you'll be able to select support
 340           for the following (non-PC) 64 bit x86 platforms:
 341                 ScaleMP vSMP
 342                 SGI Ultraviolet
 343
 344           If you have one of these systems, or if you want to build a
 345           generic distribution kernel, say Y here - otherwise say N.
 346 endif
 347 # This is an alphabetically sorted list of 64 bit extended platforms
 348 # Please maintain the alphabetic order if and when there are additions
 349
 350 config X86_VSMP
 351         bool "ScaleMP vSMP"
 352         select PARAVIRT
 353         depends on X86_64 && PCI
 354         depends on X86_EXTENDED_PLATFORM
 355         ---help---
 356           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 357           supposed to run on these EM64T-based machines.  Only choose this option
 358           if you have one of these machines.
 359
 360 config X86_UV
 361         bool "SGI Ultraviolet"
 362         depends on X86_64
 363         depends on X86_EXTENDED_PLATFORM
 364         depends on NUMA
 365         depends on X86_X2APIC
 366         ---help---
 367           This option is needed in order to support SGI Ultraviolet systems.
 368           If you don't have one of these, you should say N here.
 369
 370 # Following is an alphabetically sorted list of 32 bit extended platforms
 371 # Please maintain the alphabetic order if and when there are additions
 372
 373 config X86_ELAN
 374         bool "AMD Elan"
 375         depends on X86_32
 376         depends on X86_EXTENDED_PLATFORM
 377         ---help---
 378           Select this for an AMD Elan processor.
 379
 380           Do not use this option for K6/Athlon/Opteron processors!
 381
 382           If unsure, choose "PC-compatible" instead.
 383
 384 config X86_RDC321X
 385         bool "RDC R-321x SoC"
 386         depends on X86_32
 387         depends on X86_EXTENDED_PLATFORM
 388         select M486
 389         select X86_REBOOTFIXUPS
 390         ---help---
 391           This option is needed for RDC R-321x system-on-chip, also known
 392           as R-8610-(G).
 393           If you don't have one of these chips, you should say N here.
 394
 395 config X86_32_NON_STANDARD
 396         bool "Support non-standard 32-bit SMP architectures"
 397         depends on X86_32 && SMP
 398         depends on X86_EXTENDED_PLATFORM
 399         ---help---
 400           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 401           subarchitectures.  It is intended for a generic binary kernel.
 402           if you select them all, kernel will probe it one by one. and will
 403           fallback to default.
 404
 405 # Alphabetically sorted list of Non standard 32 bit platforms
 406
 407 config X86_NUMAQ
 408         bool "NUMAQ (IBM/Sequent)"
 409         depends on X86_32_NON_STANDARD
 410         select NUMA
 411         select X86_MPPARSE
 412         ---help---
 413           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 414           NUMA multiquad box. This changes the way that processors are
 415           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 416           of Flat Logical.  You will need a new lynxer.elf file to flash your
 417           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 418
 419 config X86_VISWS
 420         bool "SGI 320/540 (Visual Workstation)"
 421         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 422         depends on X86_32_NON_STANDARD
 423         ---help---
 424           The SGI Visual Workstation series is an IA32-based workstation
 425           based on SGI systems chips with some legacy PC hardware attached.
 426
 427           Say Y here to create a kernel to run on the SGI 320 or 540.
 428
 429           A kernel compiled for the Visual Workstation will run on general
 430           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 431
 432 config X86_SUMMIT
 433         bool "Summit/EXA (IBM x440)"
 434         depends on X86_32_NON_STANDARD
 435         ---help---
 436           This option is needed for IBM systems that use the Summit/EXA chipset.
 437           In particular, it is needed for the x440.
 438
 439 config X86_ES7000
 440         bool "Unisys ES7000 IA32 series"
 441         depends on X86_32_NON_STANDARD && X86_BIGSMP
 442         ---help---
 443           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 444           supposed to run on an IA32-based Unisys ES7000 system.
 445
 446 config SCHED_OMIT_FRAME_POINTER
 447         def_bool y
 448         prompt "Single-depth WCHAN output"
 449         depends on X86
 450         ---help---
 451           Calculate simpler /proc/<PID>/wchan values. If this option
 452           is disabled then wchan values will recurse back to the
 453           caller function. This provides more accurate wchan values,
 454           at the expense of slightly more scheduling overhead.
 455
 456           If in doubt, say "Y".
 457
 458 menuconfig PARAVIRT_GUEST
 459         bool "Paravirtualized guest support"
 460         ---help---
 461           Say Y here to get to see options related to running Linux under
 462           various hypervisors.  This option alone does not add any kernel code.
 463
 464           If you say N, all options in this submenu will be skipped and disabled.
 465
 466 if PARAVIRT_GUEST
 467
 468 source "arch/x86/xen/Kconfig"
 469
 470 config VMI
 471         bool "VMI Guest support"
 472         select PARAVIRT
 473         depends on X86_32
 474         ---help---
 475           VMI provides a paravirtualized interface to the VMware ESX server
 476           (it could be used by other hypervisors in theory too, but is not
 477           at the moment), by linking the kernel to a GPL-ed ROM module
 478           provided by the hypervisor.
 479
 480 config KVM_CLOCK
 481         bool "KVM paravirtualized clock"
 482         select PARAVIRT
 483         select PARAVIRT_CLOCK
 484         ---help---
 485           Turning on this option will allow you to run a paravirtualized clock
 486           when running over the KVM hypervisor. Instead of relying on a PIT
 487           (or probably other) emulation by the underlying device model, the host
 488           provides the guest with timing infrastructure such as time of day, and
 489           system time
 490
 491 config KVM_GUEST
 492         bool "KVM Guest support"
 493         select PARAVIRT
 494         ---help---
 495           This option enables various optimizations for running under the KVM
 496           hypervisor.
 497
 498 source "arch/x86/lguest/Kconfig"
 499
 500 config PARAVIRT
 501         bool "Enable paravirtualization code"
 502         ---help---
 503           This changes the kernel so it can modify itself when it is run
 504           under a hypervisor, potentially improving performance significantly
 505           over full virtualization.  However, when run without a hypervisor
 506           the kernel is theoretically slower and slightly larger.
 507
 508 config PARAVIRT_SPINLOCKS
 509         bool "Paravirtualization layer for spinlocks"
 510         depends on PARAVIRT && SMP && EXPERIMENTAL
 511         ---help---
 512           Paravirtualized spinlocks allow a pvops backend to replace the
 513           spinlock implementation with something virtualization-friendly
 514           (for example, block the virtual CPU rather than spinning).
 515
 516           Unfortunately the downside is an up to 5% performance hit on
 517           native kernels, with various workloads.
 518
 519           If you are unsure how to answer this question, answer N.
 520
 521 config PARAVIRT_CLOCK
 522         bool
 523         default n
 524
 525 endif
 526
 527 config PARAVIRT_DEBUG
 528         bool "paravirt-ops debugging"
 529         depends on PARAVIRT && DEBUG_KERNEL
 530         ---help---
 531           Enable to debug paravirt_ops internals.  Specifically, BUG if
 532           a paravirt_op is missing when it is called.
 533
 534 config MEMTEST
 535         bool "Memtest"
 536         ---help---
 537           This option adds a kernel parameter 'memtest', which allows memtest
 538           to be set.
 539                 memtest=0, mean disabled; -- default
 540                 memtest=1, mean do 1 test pattern;
 541                 ...
 542                 memtest=4, mean do 4 test patterns.
 543           If you are unsure how to answer this question, answer N.
 544
 545 config X86_SUMMIT_NUMA
 546         def_bool y
 547         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 548
 549 config X86_CYCLONE_TIMER
 550         def_bool y
 551         depends on X86_32_NON_STANDARD
 552
 553 source "arch/x86/Kconfig.cpu"
 554
 555 config HPET_TIMER
 556         def_bool X86_64
 557         prompt "HPET Timer Support" if X86_32
 558         ---help---
 559           Use the IA-PC HPET (High Precision Event Timer) to manage
 560           time in preference to the PIT and RTC, if a HPET is
 561           present.
 562           HPET is the next generation timer replacing legacy 8254s.
 563           The HPET provides a stable time base on SMP
 564           systems, unlike the TSC, but it is more expensive to access,
 565           as it is off-chip.  You can find the HPET spec at
 566           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 567
 568           You can safely choose Y here.  However, HPET will only be
 569           activated if the platform and the BIOS support this feature.
 570           Otherwise the 8254 will be used for timing services.
 571
 572           Choose N to continue using the legacy 8254 timer.
 573
 574 config HPET_EMULATE_RTC
 575         def_bool y
 576         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 577
 578 # Mark as embedded because too many people got it wrong.
 579 # The code disables itself when not needed.
 580 config DMI
 581         default y
 582         bool "Enable DMI scanning" if EMBEDDED
 583         ---help---
 584           Enabled scanning of DMI to identify machine quirks. Say Y
 585           here unless you have verified that your setup is not
 586           affected by entries in the DMI blacklist. Required by PNP
 587           BIOS code.
 588
 589 config GART_IOMMU
 590         bool "GART IOMMU support" if EMBEDDED
 591         default y
 592         select SWIOTLB
 593         select AGP
 594         depends on X86_64 && PCI
 595         ---help---
 596           Support for full DMA access of devices with 32bit memory access only
 597           on systems with more than 3GB. This is usually needed for USB,
 598           sound, many IDE/SATA chipsets and some other devices.
 599           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 600           based hardware IOMMU and a software bounce buffer based IOMMU used
 601           on Intel systems and as fallback.
 602           The code is only active when needed (enough memory and limited
 603           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 604           too.
 605
 606 config CALGARY_IOMMU
 607         bool "IBM Calgary IOMMU support"
 608         select SWIOTLB
 609         depends on X86_64 && PCI && EXPERIMENTAL
 610         ---help---
 611           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 612           systems. Needed to run systems with more than 3GB of memory
 613           properly with 32-bit PCI devices that do not support DAC
 614           (Double Address Cycle). Calgary also supports bus level
 615           isolation, where all DMAs pass through the IOMMU.  This
 616           prevents them from going anywhere except their intended
 617           destination. This catches hard-to-find kernel bugs and
 618           mis-behaving drivers and devices that do not use the DMA-API
 619           properly to set up their DMA buffers.  The IOMMU can be
 620           turned off at boot time with the iommu=off parameter.
 621           Normally the kernel will make the right choice by itself.
 622           If unsure, say Y.
 623
 624 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 625         def_bool y
 626         prompt "Should Calgary be enabled by default?"
 627         depends on CALGARY_IOMMU
 628         ---help---
 629           Should Calgary be enabled by default? if you choose 'y', Calgary
 630           will be used (if it exists). If you choose 'n', Calgary will not be
 631           used even if it exists. If you choose 'n' and would like to use
 632           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 633           If unsure, say Y.
 634
 635 config AMD_IOMMU
 636         bool "AMD IOMMU support"
 637         select SWIOTLB
 638         select PCI_MSI
 639         depends on X86_64 && PCI && ACPI
 640         ---help---
 641           With this option you can enable support for AMD IOMMU hardware in
 642           your system. An IOMMU is a hardware component which provides
 643           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 644           can isolate the the DMA memory of different devices and protect the
 645           system from misbehaving device drivers or hardware.
 646
 647           You can find out if your system has an AMD IOMMU if you look into
 648           your BIOS for an option to enable it or if you have an IVRS ACPI
 649           table.
 650
 651 config AMD_IOMMU_STATS
 652         bool "Export AMD IOMMU statistics to debugfs"
 653         depends on AMD_IOMMU
 654         select DEBUG_FS
 655         ---help---
 656           This option enables code in the AMD IOMMU driver to collect various
 657           statistics about whats happening in the driver and exports that
 658           information to userspace via debugfs.
 659           If unsure, say N.
 660
 661 # need this always selected by IOMMU for the VIA workaround
 662 config SWIOTLB
 663         def_bool y if X86_64
 664         ---help---
 665           Support for software bounce buffers used on x86-64 systems
 666           which don't have a hardware IOMMU (e.g. the current generation
 667           of Intel's x86-64 CPUs). Using this PCI devices which can only
 668           access 32-bits of memory can be used on systems with more than
 669           3 GB of memory. If unsure, say Y.
 670
 671 config IOMMU_HELPER
 672         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 673
 674 config IOMMU_API
 675         def_bool (AMD_IOMMU || DMAR)
 676
 677 config MAXSMP
 678         bool "Configure Maximum number of SMP Processors and NUMA Nodes"
 679         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 680         select CPUMASK_OFFSTACK
 681         default n
 682         ---help---
 683           Configure maximum number of CPUS and NUMA Nodes for this architecture.
 684           If unsure, say N.
 685
 686 config NR_CPUS
 687         int "Maximum number of CPUs" if SMP && !MAXSMP
 688         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 689         range 2 512 if SMP && !MAXSMP
 690         default "1" if !SMP
 691         default "4096" if MAXSMP
 692         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 693         default "8" if SMP
 694         ---help---
 695           This allows you to specify the maximum number of CPUs which this
 696           kernel will support.  The maximum supported value is 512 and the
 697           minimum value which makes sense is 2.
 698
 699           This is purely to save memory - each supported CPU adds
 700           approximately eight kilobytes to the kernel image.
 701
 702 config SCHED_SMT
 703         bool "SMT (Hyperthreading) scheduler support"
 704         depends on X86_HT
 705         ---help---
 706           SMT scheduler support improves the CPU scheduler's decision making
 707           when dealing with Intel Pentium 4 chips with HyperThreading at a
 708           cost of slightly increased overhead in some places. If unsure say
 709           N here.
 710
 711 config SCHED_MC
 712         def_bool y
 713         prompt "Multi-core scheduler support"
 714         depends on X86_HT
 715         ---help---
 716           Multi-core scheduler support improves the CPU scheduler's decision
 717           making when dealing with multi-core CPU chips at a cost of slightly
 718           increased overhead in some places. If unsure say N here.
 719
 720 source "kernel/Kconfig.preempt"
 721
 722 config X86_UP_APIC
 723         bool "Local APIC support on uniprocessors"
 724         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 725         ---help---
 726           A local APIC (Advanced Programmable Interrupt Controller) is an
 727           integrated interrupt controller in the CPU. If you have a single-CPU
 728           system which has a processor with a local APIC, you can say Y here to
 729           enable and use it. If you say Y here even though your machine doesn't
 730           have a local APIC, then the kernel will still run with no slowdown at
 731           all. The local APIC supports CPU-generated self-interrupts (timer,
 732           performance counters), and the NMI watchdog which detects hard
 733           lockups.
 734
 735 config X86_UP_IOAPIC
 736         bool "IO-APIC support on uniprocessors"
 737         depends on X86_UP_APIC
 738         ---help---
 739           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 740           SMP-capable replacement for PC-style interrupt controllers. Most
 741           SMP systems and many recent uniprocessor systems have one.
 742
 743           If you have a single-CPU system with an IO-APIC, you can say Y here
 744           to use it. If you say Y here even though your machine doesn't have
 745           an IO-APIC, then the kernel will still run with no slowdown at all.
 746
 747 config X86_LOCAL_APIC
 748         def_bool y
 749         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 750
 751 config X86_IO_APIC
 752         def_bool y
 753         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 754
 755 config X86_VISWS_APIC
 756         def_bool y
 757         depends on X86_32 && X86_VISWS
 758
 759 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 760         bool "Reroute for broken boot IRQs"
 761         default n
 762         depends on X86_IO_APIC
 763         ---help---
 764           This option enables a workaround that fixes a source of
 765           spurious interrupts. This is recommended when threaded
 766           interrupt handling is used on systems where the generation of
 767           superfluous "boot interrupts" cannot be disabled.
 768
 769           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 770           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 771           kernel does during interrupt handling). On chipsets where this
 772           boot IRQ generation cannot be disabled, this workaround keeps
 773           the original IRQ line masked so that only the equivalent "boot
 774           IRQ" is delivered to the CPUs. The workaround also tells the
 775           kernel to set up the IRQ handler on the boot IRQ line. In this
 776           way only one interrupt is delivered to the kernel. Otherwise
 777           the spurious second interrupt may cause the kernel to bring
 778           down (vital) interrupt lines.
 779
 780           Only affects "broken" chipsets. Interrupt sharing may be
 781           increased on these systems.
 782
 783 config X86_MCE
 784         bool "Machine Check Exception"
 785         ---help---
 786           Machine Check Exception support allows the processor to notify the
 787           kernel if it detects a problem (e.g. overheating, component failure).
 788           The action the kernel takes depends on the severity of the problem,
 789           ranging from a warning message on the console, to halting the machine.
 790           Your processor must be a Pentium or newer to support this - check the
 791           flags in /proc/cpuinfo for mce.  Note that some older Pentium systems
 792           have a design flaw which leads to false MCE events - hence MCE is
 793           disabled on all P5 processors, unless explicitly enabled with "mce"
 794           as a boot argument.  Similarly, if MCE is built in and creates a
 795           problem on some new non-standard machine, you can boot with "nomce"
 796           to disable it.  MCE support simply ignores non-MCE processors like
 797           the 386 and 486, so nearly everyone can say Y here.
 798
 799 config X86_OLD_MCE
 800         depends on X86_32 && X86_MCE
 801         bool "Use legacy machine check code (will go away)"
 802         default n
 803         select X86_ANCIENT_MCE
 804         ---help---
 805           Use the old i386 machine check code. This is merely intended for
 806           testing in a transition period. Try this if you run into any machine
 807           check related software problems, but report the problem to
 808           linux-kernel.  When in doubt say no.
 809
 810 config X86_NEW_MCE
 811         depends on X86_MCE
 812         bool
 813         default y if (!X86_OLD_MCE && X86_32) || X86_64
 814
 815 config X86_MCE_INTEL
 816         def_bool y
 817         prompt "Intel MCE features"
 818         depends on X86_NEW_MCE && X86_LOCAL_APIC
 819         ---help---
 820            Additional support for intel specific MCE features such as
 821            the thermal monitor.
 822
 823 config X86_MCE_AMD
 824         def_bool y
 825         prompt "AMD MCE features"
 826         depends on X86_NEW_MCE && X86_LOCAL_APIC
 827         ---help---
 828            Additional support for AMD specific MCE features such as
 829            the DRAM Error Threshold.
 830
 831 config X86_ANCIENT_MCE
 832         def_bool n
 833         depends on X86_32
 834         prompt "Support for old Pentium 5 / WinChip machine checks"
 835         ---help---
 836           Include support for machine check handling on old Pentium 5 or WinChip
 837           systems. These typically need to be enabled explicitely on the command
 838           line.
 839
 840 config X86_MCE_THRESHOLD
 841         depends on X86_MCE_AMD || X86_MCE_INTEL
 842         bool
 843         default y
 844
 845 config X86_MCE_INJECT
 846         depends on X86_NEW_MCE
 847         tristate "Machine check injector support"
 848         ---help---
 849           Provide support for injecting machine checks for testing purposes.
 850           If you don't know what a machine check is and you don't do kernel
 851           QA it is safe to say n.
 852
 853 config X86_MCE_NONFATAL
 854         tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
 855         depends on X86_OLD_MCE
 856         ---help---
 857           Enabling this feature starts a timer that triggers every 5 seconds which
 858           will look at the machine check registers to see if anything happened.
 859           Non-fatal problems automatically get corrected (but still logged).
 860           Disable this if you don't want to see these messages.
 861           Seeing the messages this option prints out may be indicative of dying
 862           or out-of-spec (ie, overclocked) hardware.
 863           This option only does something on certain CPUs.
 864           (AMD Athlon/Duron and Intel Pentium 4)
 865
 866 config X86_MCE_P4THERMAL
 867         bool "check for P4 thermal throttling interrupt."
 868         depends on X86_OLD_MCE && X86_MCE && (X86_UP_APIC || SMP)
 869         ---help---
 870           Enabling this feature will cause a message to be printed when the P4
 871           enters thermal throttling.
 872
 873 config X86_THERMAL_VECTOR
 874         def_bool y
 875         depends on X86_MCE_P4THERMAL || X86_MCE_INTEL
 876
 877 config VM86
 878         bool "Enable VM86 support" if EMBEDDED
 879         default y
 880         depends on X86_32
 881         ---help---
 882           This option is required by programs like DOSEMU to run 16-bit legacy
 883           code on X86 processors. It also may be needed by software like
 884           XFree86 to initialize some video cards via BIOS. Disabling this
 885           option saves about 6k.
 886
 887 config TOSHIBA
 888         tristate "Toshiba Laptop support"
 889         depends on X86_32
 890         ---help---
 891           This adds a driver to safely access the System Management Mode of
 892           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 893           not work on models with a Phoenix BIOS. The System Management Mode
 894           is used to set the BIOS and power saving options on Toshiba portables.
 895
 896           For information on utilities to make use of this driver see the
 897           Toshiba Linux utilities web site at:
 898           <http://www.buzzard.org.uk/toshiba/>.
 899
 900           Say Y if you intend to run this kernel on a Toshiba portable.
 901           Say N otherwise.
 902
 903 config I8K
 904         tristate "Dell laptop support"
 905         ---help---
 906           This adds a driver to safely access the System Management Mode
 907           of the CPU on the Dell Inspiron 8000. The System Management Mode
 908           is used to read cpu temperature and cooling fan status and to
 909           control the fans on the I8K portables.
 910
 911           This driver has been tested only on the Inspiron 8000 but it may
 912           also work with other Dell laptops. You can force loading on other
 913           models by passing the parameter `force=1' to the module. Use at
 914           your own risk.
 915
 916           For information on utilities to make use of this driver see the
 917           I8K Linux utilities web site at:
 918           <http://people.debian.org/~dz/i8k/>
 919
 920           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 921           Say N otherwise.
 922
 923 config X86_REBOOTFIXUPS
 924         bool "Enable X86 board specific fixups for reboot"
 925         depends on X86_32
 926         ---help---
 927           This enables chipset and/or board specific fixups to be done
 928           in order to get reboot to work correctly. This is only needed on
 929           some combinations of hardware and BIOS. The symptom, for which
 930           this config is intended, is when reboot ends with a stalled/hung
 931           system.
 932
 933           Currently, the only fixup is for the Geode machines using
 934           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 935
 936           Say Y if you want to enable the fixup. Currently, it's safe to
 937           enable this option even if you don't need it.
 938           Say N otherwise.
 939
 940 config MICROCODE
 941         tristate "/dev/cpu/microcode - microcode support"
 942         select FW_LOADER
 943         ---help---
 944           If you say Y here, you will be able to update the microcode on
 945           certain Intel and AMD processors. The Intel support is for the
 946           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 947           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 948           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 949           You will obviously need the actual microcode binary data itself
 950           which is not shipped with the Linux kernel.
 951
 952           This option selects the general module only, you need to select
 953           at least one vendor specific module as well.
 954
 955           To compile this driver as a module, choose M here: the
 956           module will be called microcode.
 957
 958 config MICROCODE_INTEL
 959         bool "Intel microcode patch loading support"
 960         depends on MICROCODE
 961         default MICROCODE
 962         select FW_LOADER
 963         ---help---
 964           This options enables microcode patch loading support for Intel
 965           processors.
 966
 967           For latest news and information on obtaining all the required
 968           Intel ingredients for this driver, check:
 969           <http://www.urbanmyth.org/microcode/>.
 970
 971 config MICROCODE_AMD
 972         bool "AMD microcode patch loading support"
 973         depends on MICROCODE
 974         select FW_LOADER
 975         ---help---
 976           If you select this option, microcode patch loading support for AMD
 977           processors will be enabled.
 978
 979 config MICROCODE_OLD_INTERFACE
 980         def_bool y
 981         depends on MICROCODE
 982
 983 config X86_MSR
 984         tristate "/dev/cpu/*/msr - Model-specific register support"
 985         ---help---
 986           This device gives privileged processes access to the x86
 987           Model-Specific Registers (MSRs).  It is a character device with
 988           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
 989           MSR accesses are directed to a specific CPU on multi-processor
 990           systems.
 991
 992 config X86_CPUID
 993         tristate "/dev/cpu/*/cpuid - CPU information support"
 994         ---help---
 995           This device gives processes access to the x86 CPUID instruction to
 996           be executed on a specific processor.  It is a character device
 997           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
 998           /dev/cpu/31/cpuid.
 999
1000 config X86_CPU_DEBUG
1001         tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
1002         ---help---
1003           If you select this option, this will provide various x86 CPUs
1004           information through debugfs.
1005
1006 choice
1007         prompt "High Memory Support"
1008         default HIGHMEM4G if !X86_NUMAQ
1009         default HIGHMEM64G if X86_NUMAQ
1010         depends on X86_32
1011
1012 config NOHIGHMEM
1013         bool "off"
1014         depends on !X86_NUMAQ
1015         ---help---
1016           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1017           However, the address space of 32-bit x86 processors is only 4
1018           Gigabytes large. That means that, if you have a large amount of
1019           physical memory, not all of it can be "permanently mapped" by the
1020           kernel. The physical memory that's not permanently mapped is called
1021           "high memory".
1022
1023           If you are compiling a kernel which will never run on a machine with
1024           more than 1 Gigabyte total physical RAM, answer "off" here (default
1025           choice and suitable for most users). This will result in a "3GB/1GB"
1026           split: 3GB are mapped so that each process sees a 3GB virtual memory
1027           space and the remaining part of the 4GB virtual memory space is used
1028           by the kernel to permanently map as much physical memory as
1029           possible.
1030
1031           If the machine has between 1 and 4 Gigabytes physical RAM, then
1032           answer "4GB" here.
1033
1034           If more than 4 Gigabytes is used then answer "64GB" here. This
1035           selection turns Intel PAE (Physical Address Extension) mode on.
1036           PAE implements 3-level paging on IA32 processors. PAE is fully
1037           supported by Linux, PAE mode is implemented on all recent Intel
1038           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1039           then the kernel will not boot on CPUs that don't support PAE!
1040
1041           The actual amount of total physical memory will either be
1042           auto detected or can be forced by using a kernel command line option
1043           such as "mem=256M". (Try "man bootparam" or see the documentation of
1044           your boot loader (lilo or loadlin) about how to pass options to the
1045           kernel at boot time.)
1046
1047           If unsure, say "off".
1048
1049 config HIGHMEM4G
1050         bool "4GB"
1051         depends on !X86_NUMAQ
1052         ---help---
1053           Select this if you have a 32-bit processor and between 1 and 4
1054           gigabytes of physical RAM.
1055
1056 config HIGHMEM64G
1057         bool "64GB"
1058         depends on !M386 && !M486
1059         select X86_PAE
1060         ---help---
1061           Select this if you have a 32-bit processor and more than 4
1062           gigabytes of physical RAM.
1063
1064 endchoice
1065
1066 choice
1067         depends on EXPERIMENTAL
1068         prompt "Memory split" if EMBEDDED
1069         default VMSPLIT_3G
1070         depends on X86_32
1071         ---help---
1072           Select the desired split between kernel and user memory.
1073
1074           If the address range available to the kernel is less than the
1075           physical memory installed, the remaining memory will be available
1076           as "high memory". Accessing high memory is a little more costly
1077           than low memory, as it needs to be mapped into the kernel first.
1078           Note that increasing the kernel address space limits the range
1079           available to user programs, making the address space there
1080           tighter.  Selecting anything other than the default 3G/1G split
1081           will also likely make your kernel incompatible with binary-only
1082           kernel modules.
1083
1084           If you are not absolutely sure what you are doing, leave this
1085           option alone!
1086
1087         config VMSPLIT_3G
1088                 bool "3G/1G user/kernel split"
1089         config VMSPLIT_3G_OPT
1090                 depends on !X86_PAE
1091                 bool "3G/1G user/kernel split (for full 1G low memory)"
1092         config VMSPLIT_2G
1093                 bool "2G/2G user/kernel split"
1094         config VMSPLIT_2G_OPT
1095                 depends on !X86_PAE
1096                 bool "2G/2G user/kernel split (for full 2G low memory)"
1097         config VMSPLIT_1G
1098                 bool "1G/3G user/kernel split"
1099 endchoice
1100
1101 config PAGE_OFFSET
1102         hex
1103         default 0xB0000000 if VMSPLIT_3G_OPT
1104         default 0x80000000 if VMSPLIT_2G
1105         default 0x78000000 if VMSPLIT_2G_OPT
1106         default 0x40000000 if VMSPLIT_1G
1107         default 0xC0000000
1108         depends on X86_32
1109
1110 config HIGHMEM
1111         def_bool y
1112         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1113
1114 config X86_PAE
1115         bool "PAE (Physical Address Extension) Support"
1116         depends on X86_32 && !HIGHMEM4G
1117         ---help---
1118           PAE is required for NX support, and furthermore enables
1119           larger swapspace support for non-overcommit purposes. It
1120           has the cost of more pagetable lookup overhead, and also
1121           consumes more pagetable space per process.
1122
1123 config ARCH_PHYS_ADDR_T_64BIT
1124         def_bool X86_64 || X86_PAE
1125
1126 config DIRECT_GBPAGES
1127         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1128         default y
1129         depends on X86_64
1130         ---help---
1131           Allow the kernel linear mapping to use 1GB pages on CPUs that
1132           support it. This can improve the kernel's performance a tiny bit by
1133           reducing TLB pressure. If in doubt, say "Y".
1134
1135 # Common NUMA Features
1136 config NUMA
1137         bool "Numa Memory Allocation and Scheduler Support"
1138         depends on SMP
1139         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1140         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1141         ---help---
1142           Enable NUMA (Non Uniform Memory Access) support.
1143
1144           The kernel will try to allocate memory used by a CPU on the
1145           local memory controller of the CPU and add some more
1146           NUMA awareness to the kernel.
1147
1148           For 64-bit this is recommended if the system is Intel Core i7
1149           (or later), AMD Opteron, or EM64T NUMA.
1150
1151           For 32-bit this is only needed on (rare) 32-bit-only platforms
1152           that support NUMA topologies, such as NUMAQ / Summit, or if you
1153           boot a 32-bit kernel on a 64-bit NUMA platform.
1154
1155           Otherwise, you should say N.
1156
1157 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1158         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1159
1160 config K8_NUMA
1161         def_bool y
1162         prompt "Old style AMD Opteron NUMA detection"
1163         depends on X86_64 && NUMA && PCI
1164         ---help---
1165           Enable K8 NUMA node topology detection.  You should say Y here if
1166           you have a multi processor AMD K8 system. This uses an old
1167           method to read the NUMA configuration directly from the builtin
1168           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1169           instead, which also takes priority if both are compiled in.
1170
1171 config X86_64_ACPI_NUMA
1172         def_bool y
1173         prompt "ACPI NUMA detection"
1174         depends on X86_64 && NUMA && ACPI && PCI
1175         select ACPI_NUMA
1176         ---help---
1177           Enable ACPI SRAT based node topology detection.
1178
1179 # Some NUMA nodes have memory ranges that span
1180 # other nodes.  Even though a pfn is valid and
1181 # between a node's start and end pfns, it may not
1182 # reside on that node.  See memmap_init_zone()
1183 # for details.
1184 config NODES_SPAN_OTHER_NODES
1185         def_bool y
1186         depends on X86_64_ACPI_NUMA
1187
1188 config NUMA_EMU
1189         bool "NUMA emulation"
1190         depends on X86_64 && NUMA
1191         ---help---
1192           Enable NUMA emulation. A flat machine will be split
1193           into virtual nodes when booted with "numa=fake=N", where N is the
1194           number of nodes. This is only useful for debugging.
1195
1196 config NODES_SHIFT
1197         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1198         range 1 9
1199         default "9" if MAXSMP
1200         default "6" if X86_64
1201         default "4" if X86_NUMAQ
1202         default "3"
1203         depends on NEED_MULTIPLE_NODES
1204         ---help---
1205           Specify the maximum number of NUMA Nodes available on the target
1206           system.  Increases memory reserved to accommodate various tables.
1207
1208 config HAVE_ARCH_BOOTMEM
1209         def_bool y
1210         depends on X86_32 && NUMA
1211
1212 config ARCH_HAVE_MEMORY_PRESENT
1213         def_bool y
1214         depends on X86_32 && DISCONTIGMEM
1215
1216 config NEED_NODE_MEMMAP_SIZE
1217         def_bool y
1218         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1219
1220 config HAVE_ARCH_ALLOC_REMAP
1221         def_bool y
1222         depends on X86_32 && NUMA
1223
1224 config ARCH_FLATMEM_ENABLE
1225         def_bool y
1226         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1227
1228 config ARCH_DISCONTIGMEM_ENABLE
1229         def_bool y
1230         depends on NUMA && X86_32
1231
1232 config ARCH_DISCONTIGMEM_DEFAULT
1233         def_bool y
1234         depends on NUMA && X86_32
1235
1236 config ARCH_SPARSEMEM_DEFAULT
1237         def_bool y
1238         depends on X86_64
1239
1240 config ARCH_SPARSEMEM_ENABLE
1241         def_bool y
1242         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1243         select SPARSEMEM_STATIC if X86_32
1244         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1245
1246 config ARCH_SELECT_MEMORY_MODEL
1247         def_bool y
1248         depends on ARCH_SPARSEMEM_ENABLE
1249
1250 config ARCH_MEMORY_PROBE
1251         def_bool X86_64
1252         depends on MEMORY_HOTPLUG
1253
1254 source "mm/Kconfig"
1255
1256 config HIGHPTE
1257         bool "Allocate 3rd-level pagetables from highmem"
1258         depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1259         ---help---
1260           The VM uses one page table entry for each page of physical memory.
1261           For systems with a lot of RAM, this can be wasteful of precious
1262           low memory.  Setting this option will put user-space page table
1263           entries in high memory.
1264
1265 config X86_CHECK_BIOS_CORRUPTION
1266         bool "Check for low memory corruption"
1267         ---help---
1268           Periodically check for memory corruption in low memory, which
1269           is suspected to be caused by BIOS.  Even when enabled in the
1270           configuration, it is disabled at runtime.  Enable it by
1271           setting "memory_corruption_check=1" on the kernel command
1272           line.  By default it scans the low 64k of memory every 60
1273           seconds; see the memory_corruption_check_size and
1274           memory_corruption_check_period parameters in
1275           Documentation/kernel-parameters.txt to adjust this.
1276
1277           When enabled with the default parameters, this option has
1278           almost no overhead, as it reserves a relatively small amount
1279           of memory and scans it infrequently.  It both detects corruption
1280           and prevents it from affecting the running system.
1281
1282           It is, however, intended as a diagnostic tool; if repeatable
1283           BIOS-originated corruption always affects the same memory,
1284           you can use memmap= to prevent the kernel from using that
1285           memory.
1286
1287 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1288         bool "Set the default setting of memory_corruption_check"
1289         depends on X86_CHECK_BIOS_CORRUPTION
1290         default y
1291         ---help---
1292           Set whether the default state of memory_corruption_check is
1293           on or off.
1294
1295 config X86_RESERVE_LOW_64K
1296         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1297         default y
1298         ---help---
1299           Reserve the first 64K of physical RAM on BIOSes that are known
1300           to potentially corrupt that memory range. A numbers of BIOSes are
1301           known to utilize this area during suspend/resume, so it must not
1302           be used by the kernel.
1303
1304           Set this to N if you are absolutely sure that you trust the BIOS
1305           to get all its memory reservations and usages right.
1306
1307           If you have doubts about the BIOS (e.g. suspend/resume does not
1308           work or there's kernel crashes after certain hardware hotplug
1309           events) and it's not AMI or Phoenix, then you might want to enable
1310           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1311           corruption patterns.
1312
1313           Say Y if unsure.
1314
1315 config MATH_EMULATION
1316         bool
1317         prompt "Math emulation" if X86_32
1318         ---help---
1319           Linux can emulate a math coprocessor (used for floating point
1320           operations) if you don't have one. 486DX and Pentium processors have
1321           a math coprocessor built in, 486SX and 386 do not, unless you added
1322           a 487DX or 387, respectively. (The messages during boot time can
1323           give you some hints here ["man dmesg"].) Everyone needs either a
1324           coprocessor or this emulation.
1325
1326           If you don't have a math coprocessor, you need to say Y here; if you
1327           say Y here even though you have a coprocessor, the coprocessor will
1328           be used nevertheless. (This behavior can be changed with the kernel
1329           command line option "no387", which comes handy if your coprocessor
1330           is broken. Try "man bootparam" or see the documentation of your boot
1331           loader (lilo or loadlin) about how to pass options to the kernel at
1332           boot time.) This means that it is a good idea to say Y here if you
1333           intend to use this kernel on different machines.
1334
1335           More information about the internals of the Linux math coprocessor
1336           emulation can be found in <file:arch/x86/math-emu/README>.
1337
1338           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1339           kernel, it won't hurt.
1340
1341 config MTRR
1342         bool "MTRR (Memory Type Range Register) support"
1343         ---help---
1344           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1345           the Memory Type Range Registers (MTRRs) may be used to control
1346           processor access to memory ranges. This is most useful if you have
1347           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1348           allows bus write transfers to be combined into a larger transfer
1349           before bursting over the PCI/AGP bus. This can increase performance
1350           of image write operations 2.5 times or more. Saying Y here creates a
1351           /proc/mtrr file which may be used to manipulate your processor's
1352           MTRRs. Typically the X server should use this.
1353
1354           This code has a reasonably generic interface so that similar
1355           control registers on other processors can be easily supported
1356           as well:
1357
1358           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1359           Registers (ARRs) which provide a similar functionality to MTRRs. For
1360           these, the ARRs are used to emulate the MTRRs.
1361           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1362           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1363           write-combining. All of these processors are supported by this code
1364           and it makes sense to say Y here if you have one of them.
1365
1366           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1367           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1368           can lead to all sorts of problems, so it's good to say Y here.
1369
1370           You can safely say Y even if your machine doesn't have MTRRs, you'll
1371           just add about 9 KB to your kernel.
1372
1373           See <file:Documentation/x86/mtrr.txt> for more information.
1374
1375 config MTRR_SANITIZER
1376         def_bool y
1377         prompt "MTRR cleanup support"
1378         depends on MTRR
1379         ---help---
1380           Convert MTRR layout from continuous to discrete, so X drivers can
1381           add writeback entries.
1382
1383           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1384           The largest mtrr entry size for a continuous block can be set with
1385           mtrr_chunk_size.
1386
1387           If unsure, say Y.
1388
1389 config MTRR_SANITIZER_ENABLE_DEFAULT
1390         int "MTRR cleanup enable value (0-1)"
1391         range 0 1
1392         default "0"
1393         depends on MTRR_SANITIZER
1394         ---help---
1395           Enable mtrr cleanup default value
1396
1397 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1398         int "MTRR cleanup spare reg num (0-7)"
1399         range 0 7
1400         default "1"
1401         depends on MTRR_SANITIZER
1402         ---help---
1403           mtrr cleanup spare entries default, it can be changed via
1404           mtrr_spare_reg_nr=N on the kernel command line.
1405
1406 config X86_PAT
1407         bool
1408         prompt "x86 PAT support"
1409         depends on MTRR
1410         ---help---
1411           Use PAT attributes to setup page level cache control.
1412
1413           PATs are the modern equivalents of MTRRs and are much more
1414           flexible than MTRRs.
1415
1416           Say N here if you see bootup problems (boot crash, boot hang,
1417           spontaneous reboots) or a non-working video driver.
1418
1419           If unsure, say Y.
1420
1421 config EFI
1422         bool "EFI runtime service support"
1423         depends on ACPI
1424         ---help---
1425           This enables the kernel to use EFI runtime services that are
1426           available (such as the EFI variable services).
1427
1428           This option is only useful on systems that have EFI firmware.
1429           In addition, you should use the latest ELILO loader available
1430           at <http://elilo.sourceforge.net> in order to take advantage
1431           of EFI runtime services. However, even with this option, the
1432           resultant kernel should continue to boot on existing non-EFI
1433           platforms.
1434
1435 config SECCOMP
1436         def_bool y
1437         prompt "Enable seccomp to safely compute untrusted bytecode"
1438         ---help---
1439           This kernel feature is useful for number crunching applications
1440           that may need to compute untrusted bytecode during their
1441           execution. By using pipes or other transports made available to
1442           the process as file descriptors supporting the read/write
1443           syscalls, it's possible to isolate those applications in
1444           their own address space using seccomp. Once seccomp is
1445           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1446           and the task is only allowed to execute a few safe syscalls
1447           defined by each seccomp mode.
1448
1449           If unsure, say Y. Only embedded should say N here.
1450
1451 config CC_STACKPROTECTOR_ALL
1452         bool
1453
1454 config CC_STACKPROTECTOR
1455         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1456         select CC_STACKPROTECTOR_ALL
1457         ---help---
1458           This option turns on the -fstack-protector GCC feature. This
1459           feature puts, at the beginning of functions, a canary value on
1460           the stack just before the return address, and validates
1461           the value just before actually returning.  Stack based buffer
1462           overflows (that need to overwrite this return address) now also
1463           overwrite the canary, which gets detected and the attack is then
1464           neutralized via a kernel panic.
1465
1466           This feature requires gcc version 4.2 or above, or a distribution
1467           gcc with the feature backported. Older versions are automatically
1468           detected and for those versions, this configuration option is
1469           ignored. (and a warning is printed during bootup)
1470
1471 source kernel/Kconfig.hz
1472
1473 config KEXEC
1474         bool "kexec system call"
1475         ---help---
1476           kexec is a system call that implements the ability to shutdown your
1477           current kernel, and to start another kernel.  It is like a reboot
1478           but it is independent of the system firmware.   And like a reboot
1479           you can start any kernel with it, not just Linux.
1480
1481           The name comes from the similarity to the exec system call.
1482
1483           It is an ongoing process to be certain the hardware in a machine
1484           is properly shutdown, so do not be surprised if this code does not
1485           initially work for you.  It may help to enable device hotplugging
1486           support.  As of this writing the exact hardware interface is
1487           strongly in flux, so no good recommendation can be made.
1488
1489 config CRASH_DUMP
1490         bool "kernel crash dumps"
1491         depends on X86_64 || (X86_32 && HIGHMEM)
1492         ---help---
1493           Generate crash dump after being started by kexec.
1494           This should be normally only set in special crash dump kernels
1495           which are loaded in the main kernel with kexec-tools into
1496           a specially reserved region and then later executed after
1497           a crash by kdump/kexec. The crash dump kernel must be compiled
1498           to a memory address not used by the main kernel or BIOS using
1499           PHYSICAL_START, or it must be built as a relocatable image
1500           (CONFIG_RELOCATABLE=y).
1501           For more details see Documentation/kdump/kdump.txt
1502
1503 config KEXEC_JUMP
1504         bool "kexec jump (EXPERIMENTAL)"
1505         depends on EXPERIMENTAL
1506         depends on KEXEC && HIBERNATION
1507         ---help---
1508           Jump between original kernel and kexeced kernel and invoke
1509           code in physical address mode via KEXEC
1510
1511 config PHYSICAL_START
1512         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1513         default "0x1000000"
1514         ---help---
1515           This gives the physical address where the kernel is loaded.
1516
1517           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1518           bzImage will decompress itself to above physical address and
1519           run from there. Otherwise, bzImage will run from the address where
1520           it has been loaded by the boot loader and will ignore above physical
1521           address.
1522
1523           In normal kdump cases one does not have to set/change this option
1524           as now bzImage can be compiled as a completely relocatable image
1525           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1526           address. This option is mainly useful for the folks who don't want
1527           to use a bzImage for capturing the crash dump and want to use a
1528           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1529           to be specifically compiled to run from a specific memory area
1530           (normally a reserved region) and this option comes handy.
1531
1532           So if you are using bzImage for capturing the crash dump,
1533           leave the value here unchanged to 0x1000000 and set
1534           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1535           for capturing the crash dump change this value to start of
1536           the reserved region.  In other words, it can be set based on
1537           the "X" value as specified in the "crashkernel=YM@XM"
1538           command line boot parameter passed to the panic-ed
1539           kernel. Please take a look at Documentation/kdump/kdump.txt
1540           for more details about crash dumps.
1541
1542           Usage of bzImage for capturing the crash dump is recommended as
1543           one does not have to build two kernels. Same kernel can be used
1544           as production kernel and capture kernel. Above option should have
1545           gone away after relocatable bzImage support is introduced. But it
1546           is present because there are users out there who continue to use
1547           vmlinux for dump capture. This option should go away down the
1548           line.
1549
1550           Don't change this unless you know what you are doing.
1551
1552 config RELOCATABLE
1553         bool "Build a relocatable kernel"
1554         default y
1555         ---help---
1556           This builds a kernel image that retains relocation information
1557           so it can be loaded someplace besides the default 1MB.
1558           The relocations tend to make the kernel binary about 10% larger,
1559           but are discarded at runtime.
1560
1561           One use is for the kexec on panic case where the recovery kernel
1562           must live at a different physical address than the primary
1563           kernel.
1564
1565           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1566           it has been loaded at and the compile time physical address
1567           (CONFIG_PHYSICAL_START) is ignored.
1568
1569 # Relocation on x86-32 needs some additional build support
1570 config X86_NEED_RELOCS
1571         def_bool y
1572         depends on X86_32 && RELOCATABLE
1573
1574 config PHYSICAL_ALIGN
1575         hex
1576         prompt "Alignment value to which kernel should be aligned" if X86_32
1577         default "0x1000000"
1578         range 0x2000 0x1000000
1579         ---help---
1580           This value puts the alignment restrictions on physical address
1581           where kernel is loaded and run from. Kernel is compiled for an
1582           address which meets above alignment restriction.
1583
1584           If bootloader loads the kernel at a non-aligned address and
1585           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1586           address aligned to above value and run from there.
1587
1588           If bootloader loads the kernel at a non-aligned address and
1589           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1590           load address and decompress itself to the address it has been
1591           compiled for and run from there. The address for which kernel is
1592           compiled already meets above alignment restrictions. Hence the
1593           end result is that kernel runs from a physical address meeting
1594           above alignment restrictions.
1595
1596           Don't change this unless you know what you are doing.
1597
1598 config HOTPLUG_CPU
1599         bool "Support for hot-pluggable CPUs"
1600         depends on SMP && HOTPLUG
1601         ---help---
1602           Say Y here to allow turning CPUs off and on. CPUs can be
1603           controlled through /sys/devices/system/cpu.
1604           ( Note: power management support will enable this option
1605             automatically on SMP systems. )
1606           Say N if you want to disable CPU hotplug.
1607
1608 config COMPAT_VDSO
1609         def_bool y
1610         prompt "Compat VDSO support"
1611         depends on X86_32 || IA32_EMULATION
1612         ---help---
1613           Map the 32-bit VDSO to the predictable old-style address too.
1614         ---help---
1615           Say N here if you are running a sufficiently recent glibc
1616           version (2.3.3 or later), to remove the high-mapped
1617           VDSO mapping and to exclusively use the randomized VDSO.
1618
1619           If unsure, say Y.
1620
1621 config CMDLINE_BOOL
1622         bool "Built-in kernel command line"
1623         default n
1624         ---help---
1625           Allow for specifying boot arguments to the kernel at
1626           build time.  On some systems (e.g. embedded ones), it is
1627           necessary or convenient to provide some or all of the
1628           kernel boot arguments with the kernel itself (that is,
1629           to not rely on the boot loader to provide them.)
1630
1631           To compile command line arguments into the kernel,
1632           set this option to 'Y', then fill in the
1633           the boot arguments in CONFIG_CMDLINE.
1634
1635           Systems with fully functional boot loaders (i.e. non-embedded)
1636           should leave this option set to 'N'.
1637
1638 config CMDLINE
1639         string "Built-in kernel command string"
1640         depends on CMDLINE_BOOL
1641         default ""
1642         ---help---
1643           Enter arguments here that should be compiled into the kernel
1644           image and used at boot time.  If the boot loader provides a
1645           command line at boot time, it is appended to this string to
1646           form the full kernel command line, when the system boots.
1647
1648           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1649           change this behavior.
1650
1651           In most cases, the command line (whether built-in or provided
1652           by the boot loader) should specify the device for the root
1653           file system.
1654
1655 config CMDLINE_OVERRIDE
1656         bool "Built-in command line overrides boot loader arguments"
1657         default n
1658         depends on CMDLINE_BOOL
1659         ---help---
1660           Set this option to 'Y' to have the kernel ignore the boot loader
1661           command line, and use ONLY the built-in command line.
1662
1663           This is used to work around broken boot loaders.  This should
1664           be set to 'N' under normal conditions.
1665
1666 endmenu
1667
1668 config ARCH_ENABLE_MEMORY_HOTPLUG
1669         def_bool y
1670         depends on X86_64 || (X86_32 && HIGHMEM)
1671
1672 config ARCH_ENABLE_MEMORY_HOTREMOVE
1673         def_bool y
1674         depends on MEMORY_HOTPLUG
1675
1676 config HAVE_ARCH_EARLY_PFN_TO_NID
1677         def_bool X86_64
1678         depends on NUMA
1679
1680 menu "Power management and ACPI options"
1681
1682 config ARCH_HIBERNATION_HEADER
1683         def_bool y
1684         depends on X86_64 && HIBERNATION
1685
1686 source "kernel/power/Kconfig"
1687
1688 source "drivers/acpi/Kconfig"
1689
1690 config X86_APM_BOOT
1691         bool
1692         default y
1693         depends on APM || APM_MODULE
1694
1695 menuconfig APM
1696         tristate "APM (Advanced Power Management) BIOS support"
1697         depends on X86_32 && PM_SLEEP
1698         ---help---
1699           APM is a BIOS specification for saving power using several different
1700           techniques. This is mostly useful for battery powered laptops with
1701           APM compliant BIOSes. If you say Y here, the system time will be
1702           reset after a RESUME operation, the /proc/apm device will provide
1703           battery status information, and user-space programs will receive
1704           notification of APM "events" (e.g. battery status change).
1705
1706           If you select "Y" here, you can disable actual use of the APM
1707           BIOS by passing the "apm=off" option to the kernel at boot time.
1708
1709           Note that the APM support is almost completely disabled for
1710           machines with more than one CPU.
1711
1712           In order to use APM, you will need supporting software. For location
1713           and more information, read <file:Documentation/power/pm.txt> and the
1714           Battery Powered Linux mini-HOWTO, available from
1715           <http://www.tldp.org/docs.html#howto>.
1716
1717           This driver does not spin down disk drives (see the hdparm(8)
1718           manpage ("man 8 hdparm") for that), and it doesn't turn off
1719           VESA-compliant "green" monitors.
1720
1721           This driver does not support the TI 4000M TravelMate and the ACER
1722           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1723           desktop machines also don't have compliant BIOSes, and this driver
1724           may cause those machines to panic during the boot phase.
1725
1726           Generally, if you don't have a battery in your machine, there isn't
1727           much point in using this driver and you should say N. If you get
1728           random kernel OOPSes or reboots that don't seem to be related to
1729           anything, try disabling/enabling this option (or disabling/enabling
1730           APM in your BIOS).
1731
1732           Some other things you should try when experiencing seemingly random,
1733           "weird" problems:
1734
1735           1) make sure that you have enough swap space and that it is
1736           enabled.
1737           2) pass the "no-hlt" option to the kernel
1738           3) switch on floating point emulation in the kernel and pass
1739           the "no387" option to the kernel
1740           4) pass the "floppy=nodma" option to the kernel
1741           5) pass the "mem=4M" option to the kernel (thereby disabling
1742           all but the first 4 MB of RAM)
1743           6) make sure that the CPU is not over clocked.
1744           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1745           8) disable the cache from your BIOS settings
1746           9) install a fan for the video card or exchange video RAM
1747           10) install a better fan for the CPU
1748           11) exchange RAM chips
1749           12) exchange the motherboard.
1750
1751           To compile this driver as a module, choose M here: the
1752           module will be called apm.
1753
1754 if APM
1755
1756 config APM_IGNORE_USER_SUSPEND
1757         bool "Ignore USER SUSPEND"
1758         ---help---
1759           This option will ignore USER SUSPEND requests. On machines with a
1760           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1761           series notebooks, it is necessary to say Y because of a BIOS bug.
1762
1763 config APM_DO_ENABLE
1764         bool "Enable PM at boot time"
1765         ---help---
1766           Enable APM features at boot time. From page 36 of the APM BIOS
1767           specification: "When disabled, the APM BIOS does not automatically
1768           power manage devices, enter the Standby State, enter the Suspend
1769           State, or take power saving steps in response to CPU Idle calls."
1770           This driver will make CPU Idle calls when Linux is idle (unless this
1771           feature is turned off -- see "Do CPU IDLE calls", below). This
1772           should always save battery power, but more complicated APM features
1773           will be dependent on your BIOS implementation. You may need to turn
1774           this option off if your computer hangs at boot time when using APM
1775           support, or if it beeps continuously instead of suspending. Turn
1776           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1777           T400CDT. This is off by default since most machines do fine without
1778           this feature.
1779
1780 config APM_CPU_IDLE
1781         bool "Make CPU Idle calls when idle"
1782         ---help---
1783           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1784           On some machines, this can activate improved power savings, such as
1785           a slowed CPU clock rate, when the machine is idle. These idle calls
1786           are made after the idle loop has run for some length of time (e.g.,
1787           333 mS). On some machines, this will cause a hang at boot time or
1788           whenever the CPU becomes idle. (On machines with more than one CPU,
1789           this option does nothing.)
1790
1791 config APM_DISPLAY_BLANK
1792         bool "Enable console blanking using APM"
1793         ---help---
1794           Enable console blanking using the APM. Some laptops can use this to
1795           turn off the LCD backlight when the screen blanker of the Linux
1796           virtual console blanks the screen. Note that this is only used by
1797           the virtual console screen blanker, and won't turn off the backlight
1798           when using the X Window system. This also doesn't have anything to
1799           do with your VESA-compliant power-saving monitor. Further, this
1800           option doesn't work for all laptops -- it might not turn off your
1801           backlight at all, or it might print a lot of errors to the console,
1802           especially if you are using gpm.
1803
1804 config APM_ALLOW_INTS
1805         bool "Allow interrupts during APM BIOS calls"
1806         ---help---
1807           Normally we disable external interrupts while we are making calls to
1808           the APM BIOS as a measure to lessen the effects of a badly behaving
1809           BIOS implementation.  The BIOS should reenable interrupts if it
1810           needs to.  Unfortunately, some BIOSes do not -- especially those in
1811           many of the newer IBM Thinkpads.  If you experience hangs when you
1812           suspend, try setting this to Y.  Otherwise, say N.
1813
1814 endif # APM
1815
1816 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1817
1818 source "drivers/cpuidle/Kconfig"
1819
1820 source "drivers/idle/Kconfig"
1821
1822 endmenu
1823
1824
1825 menu "Bus options (PCI etc.)"
1826
1827 config PCI
1828         bool "PCI support"
1829         default y
1830         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1831         ---help---
1832           Find out whether you have a PCI motherboard. PCI is the name of a
1833           bus system, i.e. the way the CPU talks to the other stuff inside
1834           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1835           VESA. If you have PCI, say Y, otherwise N.
1836
1837 choice
1838         prompt "PCI access mode"
1839         depends on X86_32 && PCI
1840         default PCI_GOANY
1841         ---help---
1842           On PCI systems, the BIOS can be used to detect the PCI devices and
1843           determine their configuration. However, some old PCI motherboards
1844           have BIOS bugs and may crash if this is done. Also, some embedded
1845           PCI-based systems don't have any BIOS at all. Linux can also try to
1846           detect the PCI hardware directly without using the BIOS.
1847
1848           With this option, you can specify how Linux should detect the
1849           PCI devices. If you choose "BIOS", the BIOS will be used,
1850           if you choose "Direct", the BIOS won't be used, and if you
1851           choose "MMConfig", then PCI Express MMCONFIG will be used.
1852           If you choose "Any", the kernel will try MMCONFIG, then the
1853           direct access method and falls back to the BIOS if that doesn't
1854           work. If unsure, go with the default, which is "Any".
1855
1856 config PCI_GOBIOS
1857         bool "BIOS"
1858
1859 config PCI_GOMMCONFIG
1860         bool "MMConfig"
1861
1862 config PCI_GODIRECT
1863         bool "Direct"
1864
1865 config PCI_GOOLPC
1866         bool "OLPC"
1867         depends on OLPC
1868
1869 config PCI_GOANY
1870         bool "Any"
1871
1872 endchoice
1873
1874 config PCI_BIOS
1875         def_bool y
1876         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1877
1878 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1879 config PCI_DIRECT
1880         def_bool y
1881         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1882
1883 config PCI_MMCONFIG
1884         def_bool y
1885         depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1886
1887 config PCI_OLPC
1888         def_bool y
1889         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1890
1891 config PCI_DOMAINS
1892         def_bool y
1893         depends on PCI
1894
1895 config PCI_MMCONFIG
1896         bool "Support mmconfig PCI config space access"
1897         depends on X86_64 && PCI && ACPI
1898
1899 config DMAR
1900         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1901         depends on PCI_MSI && ACPI && EXPERIMENTAL
1902         help
1903           DMA remapping (DMAR) devices support enables independent address
1904           translations for Direct Memory Access (DMA) from devices.
1905           These DMA remapping devices are reported via ACPI tables
1906           and include PCI device scope covered by these DMA
1907           remapping devices.
1908
1909 config DMAR_DEFAULT_ON
1910         def_bool y
1911         prompt "Enable DMA Remapping Devices by default"
1912         depends on DMAR
1913         help
1914           Selecting this option will enable a DMAR device at boot time if
1915           one is found. If this option is not selected, DMAR support can
1916           be enabled by passing intel_iommu=on to the kernel. It is
1917           recommended you say N here while the DMAR code remains
1918           experimental.
1919
1920 config DMAR_BROKEN_GFX_WA
1921         def_bool n
1922         prompt "Workaround broken graphics drivers (going away soon)"
1923         depends on DMAR
1924         ---help---
1925           Current Graphics drivers tend to use physical address
1926           for DMA and avoid using DMA APIs. Setting this config
1927           option permits the IOMMU driver to set a unity map for
1928           all the OS-visible memory. Hence the driver can continue
1929           to use physical addresses for DMA, at least until this
1930           option is removed in the 2.6.32 kernel.
1931
1932 config DMAR_FLOPPY_WA
1933         def_bool y
1934         depends on DMAR
1935         ---help---
1936           Floppy disk drivers are known to bypass DMA API calls
1937           thereby failing to work when IOMMU is enabled. This
1938           workaround will setup a 1:1 mapping for the first
1939           16MiB to make floppy (an ISA device) work.
1940
1941 config INTR_REMAP
1942         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1943         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1944         ---help---
1945           Supports Interrupt remapping for IO-APIC and MSI devices.
1946           To use x2apic mode in the CPU's which support x2APIC enhancements or
1947           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1948
1949 source "drivers/pci/pcie/Kconfig"
1950
1951 source "drivers/pci/Kconfig"
1952
1953 # x86_64 have no ISA slots, but do have ISA-style DMA.
1954 config ISA_DMA_API
1955         def_bool y
1956
1957 if X86_32
1958
1959 config ISA
1960         bool "ISA support"
1961         ---help---
1962           Find out whether you have ISA slots on your motherboard.  ISA is the
1963           name of a bus system, i.e. the way the CPU talks to the other stuff
1964           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1965           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1966           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1967
1968 config EISA
1969         bool "EISA support"
1970         depends on ISA
1971         ---help---
1972           The Extended Industry Standard Architecture (EISA) bus was
1973           developed as an open alternative to the IBM MicroChannel bus.
1974
1975           The EISA bus provided some of the features of the IBM MicroChannel
1976           bus while maintaining backward compatibility with cards made for
1977           the older ISA bus.  The EISA bus saw limited use between 1988 and
1978           1995 when it was made obsolete by the PCI bus.
1979
1980           Say Y here if you are building a kernel for an EISA-based machine.
1981
1982           Otherwise, say N.
1983
1984 source "drivers/eisa/Kconfig"
1985
1986 config MCA
1987         bool "MCA support"
1988         ---help---
1989           MicroChannel Architecture is found in some IBM PS/2 machines and
1990           laptops.  It is a bus system similar to PCI or ISA. See
1991           <file:Documentation/mca.txt> (and especially the web page given
1992           there) before attempting to build an MCA bus kernel.
1993
1994 source "drivers/mca/Kconfig"
1995
1996 config SCx200
1997         tristate "NatSemi SCx200 support"
1998         ---help---
1999           This provides basic support for National Semiconductor's
2000           (now AMD's) Geode processors.  The driver probes for the
2001           PCI-IDs of several on-chip devices, so its a good dependency
2002           for other scx200_* drivers.
2003
2004           If compiled as a module, the driver is named scx200.
2005
2006 config SCx200HR_TIMER
2007         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2008         depends on SCx200 && GENERIC_TIME
2009         default y
2010         ---help---
2011           This driver provides a clocksource built upon the on-chip
2012           27MHz high-resolution timer.  Its also a workaround for
2013           NSC Geode SC-1100's buggy TSC, which loses time when the
2014           processor goes idle (as is done by the scheduler).  The
2015           other workaround is idle=poll boot option.
2016
2017 config GEODE_MFGPT_TIMER
2018         def_bool y
2019         prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2020         depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2021         ---help---
2022           This driver provides a clock event source based on the MFGPT
2023           timer(s) in the CS5535 and CS5536 companion chip for the geode.
2024           MFGPTs have a better resolution and max interval than the
2025           generic PIT, and are suitable for use as high-res timers.
2026
2027 config OLPC
2028         bool "One Laptop Per Child support"
2029         default n
2030         ---help---
2031           Add support for detecting the unique features of the OLPC
2032           XO hardware.
2033
2034 endif # X86_32
2035
2036 config K8_NB
2037         def_bool y
2038         depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2039
2040 source "drivers/pcmcia/Kconfig"
2041
2042 source "drivers/pci/hotplug/Kconfig"
2043
2044 endmenu
2045
2046
2047 menu "Executable file formats / Emulations"
2048
2049 source "fs/Kconfig.binfmt"
2050
2051 config IA32_EMULATION
2052         bool "IA32 Emulation"
2053         depends on X86_64
2054         select COMPAT_BINFMT_ELF
2055         ---help---
2056           Include code to run 32-bit programs under a 64-bit kernel. You should
2057           likely turn this on, unless you're 100% sure that you don't have any
2058           32-bit programs left.
2059
2060 config IA32_AOUT
2061         tristate "IA32 a.out support"
2062         depends on IA32_EMULATION
2063         ---help---
2064           Support old a.out binaries in the 32bit emulation.
2065
2066 config COMPAT
2067         def_bool y
2068         depends on IA32_EMULATION
2069
2070 config COMPAT_FOR_U64_ALIGNMENT
2071         def_bool COMPAT
2072         depends on X86_64
2073
2074 config SYSVIPC_COMPAT
2075         def_bool y
2076         depends on COMPAT && SYSVIPC
2077
2078 endmenu
2079
2080
2081 config HAVE_ATOMIC_IOMAP
2082         def_bool y
2083         depends on X86_32
2084
2085 source "net/Kconfig"
2086
2087 source "drivers/Kconfig"
2088
2089 source "drivers/firmware/Kconfig"
2090
2091 source "fs/Kconfig"
2092
2093 source "arch/x86/Kconfig.debug"
2094
2095 source "security/Kconfig"
2096
2097 source "crypto/Kconfig"
2098
2099 source "arch/x86/kvm/Kconfig"
2100
2101 source "lib/Kconfig"