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 NEED_PER_CPU_EMBED_FIRST_CHUNK
 154         def_bool y
 155
 156 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 157         def_bool y
 158
 159 config NEED_PER_CPU_LPAGE_FIRST_CHUNK
 160         def_bool y
 161         depends on NEED_MULTIPLE_NODES
 162
 163 config HAVE_CPUMASK_OF_CPU_MAP
 164         def_bool X86_64_SMP
 165
 166 config ARCH_HIBERNATION_POSSIBLE
 167         def_bool y
 168
 169 config ARCH_SUSPEND_POSSIBLE
 170         def_bool y
 171
 172 config ZONE_DMA32
 173         bool
 174         default X86_64
 175
 176 config ARCH_POPULATES_NODE_MAP
 177         def_bool y
 178
 179 config AUDIT_ARCH
 180         bool
 181         default X86_64
 182
 183 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 184         def_bool y
 185
 186 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 187         def_bool y
 188
 189 # Use the generic interrupt handling code in kernel/irq/:
 190 config GENERIC_HARDIRQS
 191         bool
 192         default y
 193
 194 config GENERIC_HARDIRQS_NO__DO_IRQ
 195        def_bool y
 196
 197 config GENERIC_IRQ_PROBE
 198         bool
 199         default y
 200
 201 config GENERIC_PENDING_IRQ
 202         bool
 203         depends on GENERIC_HARDIRQS && SMP
 204         default y
 205
 206 config USE_GENERIC_SMP_HELPERS
 207         def_bool y
 208         depends on SMP
 209
 210 config X86_32_SMP
 211         def_bool y
 212         depends on X86_32 && SMP
 213
 214 config X86_64_SMP
 215         def_bool y
 216         depends on X86_64 && SMP
 217
 218 config X86_HT
 219         bool
 220         depends on SMP
 221         default y
 222
 223 config X86_TRAMPOLINE
 224         bool
 225         depends on SMP || (64BIT && ACPI_SLEEP)
 226         default y
 227
 228 config X86_32_LAZY_GS
 229         def_bool y
 230         depends on X86_32 && !CC_STACKPROTECTOR
 231
 232 config KTIME_SCALAR
 233         def_bool X86_32
 234 source "init/Kconfig"
 235 source "kernel/Kconfig.freezer"
 236
 237 menu "Processor type and features"
 238
 239 source "kernel/time/Kconfig"
 240
 241 config SMP
 242         bool "Symmetric multi-processing support"
 243         ---help---
 244           This enables support for systems with more than one CPU. If you have
 245           a system with only one CPU, like most personal computers, say N. If
 246           you have a system with more than one CPU, say Y.
 247
 248           If you say N here, the kernel will run on single and multiprocessor
 249           machines, but will use only one CPU of a multiprocessor machine. If
 250           you say Y here, the kernel will run on many, but not all,
 251           singleprocessor machines. On a singleprocessor machine, the kernel
 252           will run faster if you say N here.
 253
 254           Note that if you say Y here and choose architecture "586" or
 255           "Pentium" under "Processor family", the kernel will not work on 486
 256           architectures. Similarly, multiprocessor kernels for the "PPro"
 257           architecture may not work on all Pentium based boards.
 258
 259           People using multiprocessor machines who say Y here should also say
 260           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 261           Management" code will be disabled if you say Y here.
 262
 263           See also <file:Documentation/i386/IO-APIC.txt>,
 264           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 265           <http://www.tldp.org/docs.html#howto>.
 266
 267           If you don't know what to do here, say N.
 268
 269 config X86_X2APIC
 270         bool "Support x2apic"
 271         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 272         ---help---
 273           This enables x2apic support on CPUs that have this feature.
 274
 275           This allows 32-bit apic IDs (so it can support very large systems),
 276           and accesses the local apic via MSRs not via mmio.
 277
 278           If you don't know what to do here, say N.
 279
 280 config SPARSE_IRQ
 281         bool "Support sparse irq numbering"
 282         depends on PCI_MSI || HT_IRQ
 283         ---help---
 284           This enables support for sparse irqs. This is useful for distro
 285           kernels that want to define a high CONFIG_NR_CPUS value but still
 286           want to have low kernel memory footprint on smaller machines.
 287
 288           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 289             out the irq_desc[] array in a more NUMA-friendly way. )
 290
 291           If you don't know what to do here, say N.
 292
 293 config NUMA_IRQ_DESC
 294         def_bool y
 295         depends on SPARSE_IRQ && NUMA
 296
 297 config X86_MPPARSE
 298         bool "Enable MPS table" if ACPI
 299         default y
 300         depends on X86_LOCAL_APIC
 301         ---help---
 302           For old smp systems that do not have proper acpi support. Newer systems
 303           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 304
 305 config X86_BIGSMP
 306         bool "Support for big SMP systems with more than 8 CPUs"
 307         depends on X86_32 && SMP
 308         ---help---
 309           This option is needed for the systems that have more than 8 CPUs
 310
 311 if X86_32
 312 config X86_EXTENDED_PLATFORM
 313         bool "Support for extended (non-PC) x86 platforms"
 314         default y
 315         ---help---
 316           If you disable this option then the kernel will only support
 317           standard PC platforms. (which covers the vast majority of
 318           systems out there.)
 319
 320           If you enable this option then you'll be able to select support
 321           for the following (non-PC) 32 bit x86 platforms:
 322                 AMD Elan
 323                 NUMAQ (IBM/Sequent)
 324                 RDC R-321x SoC
 325                 SGI 320/540 (Visual Workstation)
 326                 Summit/EXA (IBM x440)
 327                 Unisys ES7000 IA32 series
 328
 329           If you have one of these systems, or if you want to build a
 330           generic distribution kernel, say Y here - otherwise say N.
 331 endif
 332
 333 if X86_64
 334 config X86_EXTENDED_PLATFORM
 335         bool "Support for extended (non-PC) x86 platforms"
 336         default y
 337         ---help---
 338           If you disable this option then the kernel will only support
 339           standard PC platforms. (which covers the vast majority of
 340           systems out there.)
 341
 342           If you enable this option then you'll be able to select support
 343           for the following (non-PC) 64 bit x86 platforms:
 344                 ScaleMP vSMP
 345                 SGI Ultraviolet
 346
 347           If you have one of these systems, or if you want to build a
 348           generic distribution kernel, say Y here - otherwise say N.
 349 endif
 350 # This is an alphabetically sorted list of 64 bit extended platforms
 351 # Please maintain the alphabetic order if and when there are additions
 352
 353 config X86_VSMP
 354         bool "ScaleMP vSMP"
 355         select PARAVIRT
 356         depends on X86_64 && PCI
 357         depends on X86_EXTENDED_PLATFORM
 358         ---help---
 359           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 360           supposed to run on these EM64T-based machines.  Only choose this option
 361           if you have one of these machines.
 362
 363 config X86_UV
 364         bool "SGI Ultraviolet"
 365         depends on X86_64
 366         depends on X86_EXTENDED_PLATFORM
 367         depends on NUMA
 368         depends on X86_X2APIC
 369         ---help---
 370           This option is needed in order to support SGI Ultraviolet systems.
 371           If you don't have one of these, you should say N here.
 372
 373 # Following is an alphabetically sorted list of 32 bit extended platforms
 374 # Please maintain the alphabetic order if and when there are additions
 375
 376 config X86_ELAN
 377         bool "AMD Elan"
 378         depends on X86_32
 379         depends on X86_EXTENDED_PLATFORM
 380         ---help---
 381           Select this for an AMD Elan processor.
 382
 383           Do not use this option for K6/Athlon/Opteron processors!
 384
 385           If unsure, choose "PC-compatible" instead.
 386
 387 config X86_RDC321X
 388         bool "RDC R-321x SoC"
 389         depends on X86_32
 390         depends on X86_EXTENDED_PLATFORM
 391         select M486
 392         select X86_REBOOTFIXUPS
 393         ---help---
 394           This option is needed for RDC R-321x system-on-chip, also known
 395           as R-8610-(G).
 396           If you don't have one of these chips, you should say N here.
 397
 398 config X86_32_NON_STANDARD
 399         bool "Support non-standard 32-bit SMP architectures"
 400         depends on X86_32 && SMP
 401         depends on X86_EXTENDED_PLATFORM
 402         ---help---
 403           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 404           subarchitectures.  It is intended for a generic binary kernel.
 405           if you select them all, kernel will probe it one by one. and will
 406           fallback to default.
 407
 408 # Alphabetically sorted list of Non standard 32 bit platforms
 409
 410 config X86_NUMAQ
 411         bool "NUMAQ (IBM/Sequent)"
 412         depends on X86_32_NON_STANDARD
 413         select NUMA
 414         select X86_MPPARSE
 415         ---help---
 416           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 417           NUMA multiquad box. This changes the way that processors are
 418           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 419           of Flat Logical.  You will need a new lynxer.elf file to flash your
 420           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 421
 422 config X86_VISWS
 423         bool "SGI 320/540 (Visual Workstation)"
 424         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 425         depends on X86_32_NON_STANDARD
 426         ---help---
 427           The SGI Visual Workstation series is an IA32-based workstation
 428           based on SGI systems chips with some legacy PC hardware attached.
 429
 430           Say Y here to create a kernel to run on the SGI 320 or 540.
 431
 432           A kernel compiled for the Visual Workstation will run on general
 433           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 434
 435 config X86_SUMMIT
 436         bool "Summit/EXA (IBM x440)"
 437         depends on X86_32_NON_STANDARD
 438         ---help---
 439           This option is needed for IBM systems that use the Summit/EXA chipset.
 440           In particular, it is needed for the x440.
 441
 442 config X86_ES7000
 443         bool "Unisys ES7000 IA32 series"
 444         depends on X86_32_NON_STANDARD && X86_BIGSMP
 445         ---help---
 446           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 447           supposed to run on an IA32-based Unisys ES7000 system.
 448
 449 config SCHED_OMIT_FRAME_POINTER
 450         def_bool y
 451         prompt "Single-depth WCHAN output"
 452         depends on X86
 453         ---help---
 454           Calculate simpler /proc/<PID>/wchan values. If this option
 455           is disabled then wchan values will recurse back to the
 456           caller function. This provides more accurate wchan values,
 457           at the expense of slightly more scheduling overhead.
 458
 459           If in doubt, say "Y".
 460
 461 menuconfig PARAVIRT_GUEST
 462         bool "Paravirtualized guest support"
 463         ---help---
 464           Say Y here to get to see options related to running Linux under
 465           various hypervisors.  This option alone does not add any kernel code.
 466
 467           If you say N, all options in this submenu will be skipped and disabled.
 468
 469 if PARAVIRT_GUEST
 470
 471 source "arch/x86/xen/Kconfig"
 472
 473 config VMI
 474         bool "VMI Guest support"
 475         select PARAVIRT
 476         depends on X86_32
 477         ---help---
 478           VMI provides a paravirtualized interface to the VMware ESX server
 479           (it could be used by other hypervisors in theory too, but is not
 480           at the moment), by linking the kernel to a GPL-ed ROM module
 481           provided by the hypervisor.
 482
 483 config KVM_CLOCK
 484         bool "KVM paravirtualized clock"
 485         select PARAVIRT
 486         select PARAVIRT_CLOCK
 487         ---help---
 488           Turning on this option will allow you to run a paravirtualized clock
 489           when running over the KVM hypervisor. Instead of relying on a PIT
 490           (or probably other) emulation by the underlying device model, the host
 491           provides the guest with timing infrastructure such as time of day, and
 492           system time
 493
 494 config KVM_GUEST
 495         bool "KVM Guest support"
 496         select PARAVIRT
 497         ---help---
 498           This option enables various optimizations for running under the KVM
 499           hypervisor.
 500
 501 source "arch/x86/lguest/Kconfig"
 502
 503 config PARAVIRT
 504         bool "Enable paravirtualization code"
 505         ---help---
 506           This changes the kernel so it can modify itself when it is run
 507           under a hypervisor, potentially improving performance significantly
 508           over full virtualization.  However, when run without a hypervisor
 509           the kernel is theoretically slower and slightly larger.
 510
 511 config PARAVIRT_SPINLOCKS
 512         bool "Paravirtualization layer for spinlocks"
 513         depends on PARAVIRT && SMP && EXPERIMENTAL
 514         ---help---
 515           Paravirtualized spinlocks allow a pvops backend to replace the
 516           spinlock implementation with something virtualization-friendly
 517           (for example, block the virtual CPU rather than spinning).
 518
 519           Unfortunately the downside is an up to 5% performance hit on
 520           native kernels, with various workloads.
 521
 522           If you are unsure how to answer this question, answer N.
 523
 524 config PARAVIRT_CLOCK
 525         bool
 526         default n
 527
 528 endif
 529
 530 config PARAVIRT_DEBUG
 531         bool "paravirt-ops debugging"
 532         depends on PARAVIRT && DEBUG_KERNEL
 533         ---help---
 534           Enable to debug paravirt_ops internals.  Specifically, BUG if
 535           a paravirt_op is missing when it is called.
 536
 537 config MEMTEST
 538         bool "Memtest"
 539         ---help---
 540           This option adds a kernel parameter 'memtest', which allows memtest
 541           to be set.
 542                 memtest=0, mean disabled; -- default
 543                 memtest=1, mean do 1 test pattern;
 544                 ...
 545                 memtest=4, mean do 4 test patterns.
 546           If you are unsure how to answer this question, answer N.
 547
 548 config X86_SUMMIT_NUMA
 549         def_bool y
 550         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 551
 552 config X86_CYCLONE_TIMER
 553         def_bool y
 554         depends on X86_32_NON_STANDARD
 555
 556 source "arch/x86/Kconfig.cpu"
 557
 558 config HPET_TIMER
 559         def_bool X86_64
 560         prompt "HPET Timer Support" if X86_32
 561         ---help---
 562           Use the IA-PC HPET (High Precision Event Timer) to manage
 563           time in preference to the PIT and RTC, if a HPET is
 564           present.
 565           HPET is the next generation timer replacing legacy 8254s.
 566           The HPET provides a stable time base on SMP
 567           systems, unlike the TSC, but it is more expensive to access,
 568           as it is off-chip.  You can find the HPET spec at
 569           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 570
 571           You can safely choose Y here.  However, HPET will only be
 572           activated if the platform and the BIOS support this feature.
 573           Otherwise the 8254 will be used for timing services.
 574
 575           Choose N to continue using the legacy 8254 timer.
 576
 577 config HPET_EMULATE_RTC
 578         def_bool y
 579         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 580
 581 # Mark as embedded because too many people got it wrong.
 582 # The code disables itself when not needed.
 583 config DMI
 584         default y
 585         bool "Enable DMI scanning" if EMBEDDED
 586         ---help---
 587           Enabled scanning of DMI to identify machine quirks. Say Y
 588           here unless you have verified that your setup is not
 589           affected by entries in the DMI blacklist. Required by PNP
 590           BIOS code.
 591
 592 config GART_IOMMU
 593         bool "GART IOMMU support" if EMBEDDED
 594         default y
 595         select SWIOTLB
 596         select AGP
 597         depends on X86_64 && PCI
 598         ---help---
 599           Support for full DMA access of devices with 32bit memory access only
 600           on systems with more than 3GB. This is usually needed for USB,
 601           sound, many IDE/SATA chipsets and some other devices.
 602           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 603           based hardware IOMMU and a software bounce buffer based IOMMU used
 604           on Intel systems and as fallback.
 605           The code is only active when needed (enough memory and limited
 606           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 607           too.
 608
 609 config CALGARY_IOMMU
 610         bool "IBM Calgary IOMMU support"
 611         select SWIOTLB
 612         depends on X86_64 && PCI && EXPERIMENTAL
 613         ---help---
 614           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 615           systems. Needed to run systems with more than 3GB of memory
 616           properly with 32-bit PCI devices that do not support DAC
 617           (Double Address Cycle). Calgary also supports bus level
 618           isolation, where all DMAs pass through the IOMMU.  This
 619           prevents them from going anywhere except their intended
 620           destination. This catches hard-to-find kernel bugs and
 621           mis-behaving drivers and devices that do not use the DMA-API
 622           properly to set up their DMA buffers.  The IOMMU can be
 623           turned off at boot time with the iommu=off parameter.
 624           Normally the kernel will make the right choice by itself.
 625           If unsure, say Y.
 626
 627 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 628         def_bool y
 629         prompt "Should Calgary be enabled by default?"
 630         depends on CALGARY_IOMMU
 631         ---help---
 632           Should Calgary be enabled by default? if you choose 'y', Calgary
 633           will be used (if it exists). If you choose 'n', Calgary will not be
 634           used even if it exists. If you choose 'n' and would like to use
 635           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 636           If unsure, say Y.
 637
 638 config AMD_IOMMU
 639         bool "AMD IOMMU support"
 640         select SWIOTLB
 641         select PCI_MSI
 642         depends on X86_64 && PCI && ACPI
 643         ---help---
 644           With this option you can enable support for AMD IOMMU hardware in
 645           your system. An IOMMU is a hardware component which provides
 646           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 647           can isolate the the DMA memory of different devices and protect the
 648           system from misbehaving device drivers or hardware.
 649
 650           You can find out if your system has an AMD IOMMU if you look into
 651           your BIOS for an option to enable it or if you have an IVRS ACPI
 652           table.
 653
 654 config AMD_IOMMU_STATS
 655         bool "Export AMD IOMMU statistics to debugfs"
 656         depends on AMD_IOMMU
 657         select DEBUG_FS
 658         ---help---
 659           This option enables code in the AMD IOMMU driver to collect various
 660           statistics about whats happening in the driver and exports that
 661           information to userspace via debugfs.
 662           If unsure, say N.
 663
 664 # need this always selected by IOMMU for the VIA workaround
 665 config SWIOTLB
 666         def_bool y if X86_64
 667         ---help---
 668           Support for software bounce buffers used on x86-64 systems
 669           which don't have a hardware IOMMU (e.g. the current generation
 670           of Intel's x86-64 CPUs). Using this PCI devices which can only
 671           access 32-bits of memory can be used on systems with more than
 672           3 GB of memory. If unsure, say Y.
 673
 674 config IOMMU_HELPER
 675         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 676
 677 config IOMMU_API
 678         def_bool (AMD_IOMMU || DMAR)
 679
 680 config MAXSMP
 681         bool "Configure Maximum number of SMP Processors and NUMA Nodes"
 682         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 683         select CPUMASK_OFFSTACK
 684         default n
 685         ---help---
 686           Configure maximum number of CPUS and NUMA Nodes for this architecture.
 687           If unsure, say N.
 688
 689 config NR_CPUS
 690         int "Maximum number of CPUs" if SMP && !MAXSMP
 691         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 692         range 2 512 if SMP && !MAXSMP
 693         default "1" if !SMP
 694         default "4096" if MAXSMP
 695         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 696         default "8" if SMP
 697         ---help---
 698           This allows you to specify the maximum number of CPUs which this
 699           kernel will support.  The maximum supported value is 512 and the
 700           minimum value which makes sense is 2.
 701
 702           This is purely to save memory - each supported CPU adds
 703           approximately eight kilobytes to the kernel image.
 704
 705 config SCHED_SMT
 706         bool "SMT (Hyperthreading) scheduler support"
 707         depends on X86_HT
 708         ---help---
 709           SMT scheduler support improves the CPU scheduler's decision making
 710           when dealing with Intel Pentium 4 chips with HyperThreading at a
 711           cost of slightly increased overhead in some places. If unsure say
 712           N here.
 713
 714 config SCHED_MC
 715         def_bool y
 716         prompt "Multi-core scheduler support"
 717         depends on X86_HT
 718         ---help---
 719           Multi-core scheduler support improves the CPU scheduler's decision
 720           making when dealing with multi-core CPU chips at a cost of slightly
 721           increased overhead in some places. If unsure say N here.
 722
 723 source "kernel/Kconfig.preempt"
 724
 725 config X86_UP_APIC
 726         bool "Local APIC support on uniprocessors"
 727         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 728         ---help---
 729           A local APIC (Advanced Programmable Interrupt Controller) is an
 730           integrated interrupt controller in the CPU. If you have a single-CPU
 731           system which has a processor with a local APIC, you can say Y here to
 732           enable and use it. If you say Y here even though your machine doesn't
 733           have a local APIC, then the kernel will still run with no slowdown at
 734           all. The local APIC supports CPU-generated self-interrupts (timer,
 735           performance counters), and the NMI watchdog which detects hard
 736           lockups.
 737
 738 config X86_UP_IOAPIC
 739         bool "IO-APIC support on uniprocessors"
 740         depends on X86_UP_APIC
 741         ---help---
 742           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 743           SMP-capable replacement for PC-style interrupt controllers. Most
 744           SMP systems and many recent uniprocessor systems have one.
 745
 746           If you have a single-CPU system with an IO-APIC, you can say Y here
 747           to use it. If you say Y here even though your machine doesn't have
 748           an IO-APIC, then the kernel will still run with no slowdown at all.
 749
 750 config X86_LOCAL_APIC
 751         def_bool y
 752         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 753
 754 config X86_IO_APIC
 755         def_bool y
 756         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 757
 758 config X86_VISWS_APIC
 759         def_bool y
 760         depends on X86_32 && X86_VISWS
 761
 762 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 763         bool "Reroute for broken boot IRQs"
 764         default n
 765         depends on X86_IO_APIC
 766         ---help---
 767           This option enables a workaround that fixes a source of
 768           spurious interrupts. This is recommended when threaded
 769           interrupt handling is used on systems where the generation of
 770           superfluous "boot interrupts" cannot be disabled.
 771
 772           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 773           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 774           kernel does during interrupt handling). On chipsets where this
 775           boot IRQ generation cannot be disabled, this workaround keeps
 776           the original IRQ line masked so that only the equivalent "boot
 777           IRQ" is delivered to the CPUs. The workaround also tells the
 778           kernel to set up the IRQ handler on the boot IRQ line. In this
 779           way only one interrupt is delivered to the kernel. Otherwise
 780           the spurious second interrupt may cause the kernel to bring
 781           down (vital) interrupt lines.
 782
 783           Only affects "broken" chipsets. Interrupt sharing may be
 784           increased on these systems.
 785
 786 config X86_MCE
 787         bool "Machine Check Exception"
 788         ---help---
 789           Machine Check Exception support allows the processor to notify the
 790           kernel if it detects a problem (e.g. overheating, component failure).
 791           The action the kernel takes depends on the severity of the problem,
 792           ranging from a warning message on the console, to halting the machine.
 793           Your processor must be a Pentium or newer to support this - check the
 794           flags in /proc/cpuinfo for mce.  Note that some older Pentium systems
 795           have a design flaw which leads to false MCE events - hence MCE is
 796           disabled on all P5 processors, unless explicitly enabled with "mce"
 797           as a boot argument.  Similarly, if MCE is built in and creates a
 798           problem on some new non-standard machine, you can boot with "nomce"
 799           to disable it.  MCE support simply ignores non-MCE processors like
 800           the 386 and 486, so nearly everyone can say Y here.
 801
 802 config X86_OLD_MCE
 803         depends on X86_32 && X86_MCE
 804         bool "Use legacy machine check code (will go away)"
 805         default n
 806         select X86_ANCIENT_MCE
 807         ---help---
 808           Use the old i386 machine check code. This is merely intended for
 809           testing in a transition period. Try this if you run into any machine
 810           check related software problems, but report the problem to
 811           linux-kernel.  When in doubt say no.
 812
 813 config X86_NEW_MCE
 814         depends on X86_MCE
 815         bool
 816         default y if (!X86_OLD_MCE && X86_32) || X86_64
 817
 818 config X86_MCE_INTEL
 819         def_bool y
 820         prompt "Intel MCE features"
 821         depends on X86_NEW_MCE && X86_LOCAL_APIC
 822         ---help---
 823            Additional support for intel specific MCE features such as
 824            the thermal monitor.
 825
 826 config X86_MCE_AMD
 827         def_bool y
 828         prompt "AMD MCE features"
 829         depends on X86_NEW_MCE && X86_LOCAL_APIC
 830         ---help---
 831            Additional support for AMD specific MCE features such as
 832            the DRAM Error Threshold.
 833
 834 config X86_ANCIENT_MCE
 835         def_bool n
 836         depends on X86_32
 837         prompt "Support for old Pentium 5 / WinChip machine checks"
 838         ---help---
 839           Include support for machine check handling on old Pentium 5 or WinChip
 840           systems. These typically need to be enabled explicitely on the command
 841           line.
 842
 843 config X86_MCE_THRESHOLD
 844         depends on X86_MCE_AMD || X86_MCE_INTEL
 845         bool
 846         default y
 847
 848 config X86_MCE_INJECT
 849         depends on X86_NEW_MCE
 850         tristate "Machine check injector support"
 851         ---help---
 852           Provide support for injecting machine checks for testing purposes.
 853           If you don't know what a machine check is and you don't do kernel
 854           QA it is safe to say n.
 855
 856 config X86_MCE_NONFATAL
 857         tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
 858         depends on X86_OLD_MCE
 859         ---help---
 860           Enabling this feature starts a timer that triggers every 5 seconds which
 861           will look at the machine check registers to see if anything happened.
 862           Non-fatal problems automatically get corrected (but still logged).
 863           Disable this if you don't want to see these messages.
 864           Seeing the messages this option prints out may be indicative of dying
 865           or out-of-spec (ie, overclocked) hardware.
 866           This option only does something on certain CPUs.
 867           (AMD Athlon/Duron and Intel Pentium 4)
 868
 869 config X86_MCE_P4THERMAL
 870         bool "check for P4 thermal throttling interrupt."
 871         depends on X86_OLD_MCE && X86_MCE && (X86_UP_APIC || SMP)
 872         ---help---
 873           Enabling this feature will cause a message to be printed when the P4
 874           enters thermal throttling.
 875
 876 config X86_THERMAL_VECTOR
 877         def_bool y
 878         depends on X86_MCE_P4THERMAL || X86_MCE_INTEL
 879
 880 config VM86
 881         bool "Enable VM86 support" if EMBEDDED
 882         default y
 883         depends on X86_32
 884         ---help---
 885           This option is required by programs like DOSEMU to run 16-bit legacy
 886           code on X86 processors. It also may be needed by software like
 887           XFree86 to initialize some video cards via BIOS. Disabling this
 888           option saves about 6k.
 889
 890 config TOSHIBA
 891         tristate "Toshiba Laptop support"
 892         depends on X86_32
 893         ---help---
 894           This adds a driver to safely access the System Management Mode of
 895           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 896           not work on models with a Phoenix BIOS. The System Management Mode
 897           is used to set the BIOS and power saving options on Toshiba portables.
 898
 899           For information on utilities to make use of this driver see the
 900           Toshiba Linux utilities web site at:
 901           <http://www.buzzard.org.uk/toshiba/>.
 902
 903           Say Y if you intend to run this kernel on a Toshiba portable.
 904           Say N otherwise.
 905
 906 config I8K
 907         tristate "Dell laptop support"
 908         ---help---
 909           This adds a driver to safely access the System Management Mode
 910           of the CPU on the Dell Inspiron 8000. The System Management Mode
 911           is used to read cpu temperature and cooling fan status and to
 912           control the fans on the I8K portables.
 913
 914           This driver has been tested only on the Inspiron 8000 but it may
 915           also work with other Dell laptops. You can force loading on other
 916           models by passing the parameter `force=1' to the module. Use at
 917           your own risk.
 918
 919           For information on utilities to make use of this driver see the
 920           I8K Linux utilities web site at:
 921           <http://people.debian.org/~dz/i8k/>
 922
 923           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 924           Say N otherwise.
 925
 926 config X86_REBOOTFIXUPS
 927         bool "Enable X86 board specific fixups for reboot"
 928         depends on X86_32
 929         ---help---
 930           This enables chipset and/or board specific fixups to be done
 931           in order to get reboot to work correctly. This is only needed on
 932           some combinations of hardware and BIOS. The symptom, for which
 933           this config is intended, is when reboot ends with a stalled/hung
 934           system.
 935
 936           Currently, the only fixup is for the Geode machines using
 937           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 938
 939           Say Y if you want to enable the fixup. Currently, it's safe to
 940           enable this option even if you don't need it.
 941           Say N otherwise.
 942
 943 config MICROCODE
 944         tristate "/dev/cpu/microcode - microcode support"
 945         select FW_LOADER
 946         ---help---
 947           If you say Y here, you will be able to update the microcode on
 948           certain Intel and AMD processors. The Intel support is for the
 949           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 950           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 951           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 952           You will obviously need the actual microcode binary data itself
 953           which is not shipped with the Linux kernel.
 954
 955           This option selects the general module only, you need to select
 956           at least one vendor specific module as well.
 957
 958           To compile this driver as a module, choose M here: the
 959           module will be called microcode.
 960
 961 config MICROCODE_INTEL
 962         bool "Intel microcode patch loading support"
 963         depends on MICROCODE
 964         default MICROCODE
 965         select FW_LOADER
 966         ---help---
 967           This options enables microcode patch loading support for Intel
 968           processors.
 969
 970           For latest news and information on obtaining all the required
 971           Intel ingredients for this driver, check:
 972           <http://www.urbanmyth.org/microcode/>.
 973
 974 config MICROCODE_AMD
 975         bool "AMD microcode patch loading support"
 976         depends on MICROCODE
 977         select FW_LOADER
 978         ---help---
 979           If you select this option, microcode patch loading support for AMD
 980           processors will be enabled.
 981
 982 config MICROCODE_OLD_INTERFACE
 983         def_bool y
 984         depends on MICROCODE
 985
 986 config X86_MSR
 987         tristate "/dev/cpu/*/msr - Model-specific register support"
 988         ---help---
 989           This device gives privileged processes access to the x86
 990           Model-Specific Registers (MSRs).  It is a character device with
 991           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
 992           MSR accesses are directed to a specific CPU on multi-processor
 993           systems.
 994
 995 config X86_CPUID
 996         tristate "/dev/cpu/*/cpuid - CPU information support"
 997         ---help---
 998           This device gives processes access to the x86 CPUID instruction to
 999           be executed on a specific processor.  It is a character device
1000           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1001           /dev/cpu/31/cpuid.
1002
1003 config X86_CPU_DEBUG
1004         tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support"
1005         ---help---
1006           If you select this option, this will provide various x86 CPUs
1007           information through debugfs.
1008
1009 choice
1010         prompt "High Memory Support"
1011         default HIGHMEM4G if !X86_NUMAQ
1012         default HIGHMEM64G if X86_NUMAQ
1013         depends on X86_32
1014
1015 config NOHIGHMEM
1016         bool "off"
1017         depends on !X86_NUMAQ
1018         ---help---
1019           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1020           However, the address space of 32-bit x86 processors is only 4
1021           Gigabytes large. That means that, if you have a large amount of
1022           physical memory, not all of it can be "permanently mapped" by the
1023           kernel. The physical memory that's not permanently mapped is called
1024           "high memory".
1025
1026           If you are compiling a kernel which will never run on a machine with
1027           more than 1 Gigabyte total physical RAM, answer "off" here (default
1028           choice and suitable for most users). This will result in a "3GB/1GB"
1029           split: 3GB are mapped so that each process sees a 3GB virtual memory
1030           space and the remaining part of the 4GB virtual memory space is used
1031           by the kernel to permanently map as much physical memory as
1032           possible.
1033
1034           If the machine has between 1 and 4 Gigabytes physical RAM, then
1035           answer "4GB" here.
1036
1037           If more than 4 Gigabytes is used then answer "64GB" here. This
1038           selection turns Intel PAE (Physical Address Extension) mode on.
1039           PAE implements 3-level paging on IA32 processors. PAE is fully
1040           supported by Linux, PAE mode is implemented on all recent Intel
1041           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1042           then the kernel will not boot on CPUs that don't support PAE!
1043
1044           The actual amount of total physical memory will either be
1045           auto detected or can be forced by using a kernel command line option
1046           such as "mem=256M". (Try "man bootparam" or see the documentation of
1047           your boot loader (lilo or loadlin) about how to pass options to the
1048           kernel at boot time.)
1049
1050           If unsure, say "off".
1051
1052 config HIGHMEM4G
1053         bool "4GB"
1054         depends on !X86_NUMAQ
1055         ---help---
1056           Select this if you have a 32-bit processor and between 1 and 4
1057           gigabytes of physical RAM.
1058
1059 config HIGHMEM64G
1060         bool "64GB"
1061         depends on !M386 && !M486
1062         select X86_PAE
1063         ---help---
1064           Select this if you have a 32-bit processor and more than 4
1065           gigabytes of physical RAM.
1066
1067 endchoice
1068
1069 choice
1070         depends on EXPERIMENTAL
1071         prompt "Memory split" if EMBEDDED
1072         default VMSPLIT_3G
1073         depends on X86_32
1074         ---help---
1075           Select the desired split between kernel and user memory.
1076
1077           If the address range available to the kernel is less than the
1078           physical memory installed, the remaining memory will be available
1079           as "high memory". Accessing high memory is a little more costly
1080           than low memory, as it needs to be mapped into the kernel first.
1081           Note that increasing the kernel address space limits the range
1082           available to user programs, making the address space there
1083           tighter.  Selecting anything other than the default 3G/1G split
1084           will also likely make your kernel incompatible with binary-only
1085           kernel modules.
1086
1087           If you are not absolutely sure what you are doing, leave this
1088           option alone!
1089
1090         config VMSPLIT_3G
1091                 bool "3G/1G user/kernel split"
1092         config VMSPLIT_3G_OPT
1093                 depends on !X86_PAE
1094                 bool "3G/1G user/kernel split (for full 1G low memory)"
1095         config VMSPLIT_2G
1096                 bool "2G/2G user/kernel split"
1097         config VMSPLIT_2G_OPT
1098                 depends on !X86_PAE
1099                 bool "2G/2G user/kernel split (for full 2G low memory)"
1100         config VMSPLIT_1G
1101                 bool "1G/3G user/kernel split"
1102 endchoice
1103
1104 config PAGE_OFFSET
1105         hex
1106         default 0xB0000000 if VMSPLIT_3G_OPT
1107         default 0x80000000 if VMSPLIT_2G
1108         default 0x78000000 if VMSPLIT_2G_OPT
1109         default 0x40000000 if VMSPLIT_1G
1110         default 0xC0000000
1111         depends on X86_32
1112
1113 config HIGHMEM
1114         def_bool y
1115         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1116
1117 config X86_PAE
1118         bool "PAE (Physical Address Extension) Support"
1119         depends on X86_32 && !HIGHMEM4G
1120         ---help---
1121           PAE is required for NX support, and furthermore enables
1122           larger swapspace support for non-overcommit purposes. It
1123           has the cost of more pagetable lookup overhead, and also
1124           consumes more pagetable space per process.
1125
1126 config ARCH_PHYS_ADDR_T_64BIT
1127         def_bool X86_64 || X86_PAE
1128
1129 config DIRECT_GBPAGES
1130         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1131         default y
1132         depends on X86_64
1133         ---help---
1134           Allow the kernel linear mapping to use 1GB pages on CPUs that
1135           support it. This can improve the kernel's performance a tiny bit by
1136           reducing TLB pressure. If in doubt, say "Y".
1137
1138 # Common NUMA Features
1139 config NUMA
1140         bool "Numa Memory Allocation and Scheduler Support"
1141         depends on SMP
1142         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1143         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1144         ---help---
1145           Enable NUMA (Non Uniform Memory Access) support.
1146
1147           The kernel will try to allocate memory used by a CPU on the
1148           local memory controller of the CPU and add some more
1149           NUMA awareness to the kernel.
1150
1151           For 64-bit this is recommended if the system is Intel Core i7
1152           (or later), AMD Opteron, or EM64T NUMA.
1153
1154           For 32-bit this is only needed on (rare) 32-bit-only platforms
1155           that support NUMA topologies, such as NUMAQ / Summit, or if you
1156           boot a 32-bit kernel on a 64-bit NUMA platform.
1157
1158           Otherwise, you should say N.
1159
1160 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1161         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1162
1163 config K8_NUMA
1164         def_bool y
1165         prompt "Old style AMD Opteron NUMA detection"
1166         depends on X86_64 && NUMA && PCI
1167         ---help---
1168           Enable K8 NUMA node topology detection.  You should say Y here if
1169           you have a multi processor AMD K8 system. This uses an old
1170           method to read the NUMA configuration directly from the builtin
1171           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1172           instead, which also takes priority if both are compiled in.
1173
1174 config X86_64_ACPI_NUMA
1175         def_bool y
1176         prompt "ACPI NUMA detection"
1177         depends on X86_64 && NUMA && ACPI && PCI
1178         select ACPI_NUMA
1179         ---help---
1180           Enable ACPI SRAT based node topology detection.
1181
1182 # Some NUMA nodes have memory ranges that span
1183 # other nodes.  Even though a pfn is valid and
1184 # between a node's start and end pfns, it may not
1185 # reside on that node.  See memmap_init_zone()
1186 # for details.
1187 config NODES_SPAN_OTHER_NODES
1188         def_bool y
1189         depends on X86_64_ACPI_NUMA
1190
1191 config NUMA_EMU
1192         bool "NUMA emulation"
1193         depends on X86_64 && NUMA
1194         ---help---
1195           Enable NUMA emulation. A flat machine will be split
1196           into virtual nodes when booted with "numa=fake=N", where N is the
1197           number of nodes. This is only useful for debugging.
1198
1199 config NODES_SHIFT
1200         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1201         range 1 9
1202         default "9" if MAXSMP
1203         default "6" if X86_64
1204         default "4" if X86_NUMAQ
1205         default "3"
1206         depends on NEED_MULTIPLE_NODES
1207         ---help---
1208           Specify the maximum number of NUMA Nodes available on the target
1209           system.  Increases memory reserved to accommodate various tables.
1210
1211 config HAVE_ARCH_BOOTMEM
1212         def_bool y
1213         depends on X86_32 && NUMA
1214
1215 config ARCH_HAVE_MEMORY_PRESENT
1216         def_bool y
1217         depends on X86_32 && DISCONTIGMEM
1218
1219 config NEED_NODE_MEMMAP_SIZE
1220         def_bool y
1221         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1222
1223 config HAVE_ARCH_ALLOC_REMAP
1224         def_bool y
1225         depends on X86_32 && NUMA
1226
1227 config ARCH_FLATMEM_ENABLE
1228         def_bool y
1229         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1230
1231 config ARCH_DISCONTIGMEM_ENABLE
1232         def_bool y
1233         depends on NUMA && X86_32
1234
1235 config ARCH_DISCONTIGMEM_DEFAULT
1236         def_bool y
1237         depends on NUMA && X86_32
1238
1239 config ARCH_SPARSEMEM_DEFAULT
1240         def_bool y
1241         depends on X86_64
1242
1243 config ARCH_SPARSEMEM_ENABLE
1244         def_bool y
1245         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1246         select SPARSEMEM_STATIC if X86_32
1247         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1248
1249 config ARCH_SELECT_MEMORY_MODEL
1250         def_bool y
1251         depends on ARCH_SPARSEMEM_ENABLE
1252
1253 config ARCH_MEMORY_PROBE
1254         def_bool X86_64
1255         depends on MEMORY_HOTPLUG
1256
1257 source "mm/Kconfig"
1258
1259 config HIGHPTE
1260         bool "Allocate 3rd-level pagetables from highmem"
1261         depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1262         ---help---
1263           The VM uses one page table entry for each page of physical memory.
1264           For systems with a lot of RAM, this can be wasteful of precious
1265           low memory.  Setting this option will put user-space page table
1266           entries in high memory.
1267
1268 config X86_CHECK_BIOS_CORRUPTION
1269         bool "Check for low memory corruption"
1270         ---help---
1271           Periodically check for memory corruption in low memory, which
1272           is suspected to be caused by BIOS.  Even when enabled in the
1273           configuration, it is disabled at runtime.  Enable it by
1274           setting "memory_corruption_check=1" on the kernel command
1275           line.  By default it scans the low 64k of memory every 60
1276           seconds; see the memory_corruption_check_size and
1277           memory_corruption_check_period parameters in
1278           Documentation/kernel-parameters.txt to adjust this.
1279
1280           When enabled with the default parameters, this option has
1281           almost no overhead, as it reserves a relatively small amount
1282           of memory and scans it infrequently.  It both detects corruption
1283           and prevents it from affecting the running system.
1284
1285           It is, however, intended as a diagnostic tool; if repeatable
1286           BIOS-originated corruption always affects the same memory,
1287           you can use memmap= to prevent the kernel from using that
1288           memory.
1289
1290 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1291         bool "Set the default setting of memory_corruption_check"
1292         depends on X86_CHECK_BIOS_CORRUPTION
1293         default y
1294         ---help---
1295           Set whether the default state of memory_corruption_check is
1296           on or off.
1297
1298 config X86_RESERVE_LOW_64K
1299         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1300         default y
1301         ---help---
1302           Reserve the first 64K of physical RAM on BIOSes that are known
1303           to potentially corrupt that memory range. A numbers of BIOSes are
1304           known to utilize this area during suspend/resume, so it must not
1305           be used by the kernel.
1306
1307           Set this to N if you are absolutely sure that you trust the BIOS
1308           to get all its memory reservations and usages right.
1309
1310           If you have doubts about the BIOS (e.g. suspend/resume does not
1311           work or there's kernel crashes after certain hardware hotplug
1312           events) and it's not AMI or Phoenix, then you might want to enable
1313           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1314           corruption patterns.
1315
1316           Say Y if unsure.
1317
1318 config MATH_EMULATION
1319         bool
1320         prompt "Math emulation" if X86_32
1321         ---help---
1322           Linux can emulate a math coprocessor (used for floating point
1323           operations) if you don't have one. 486DX and Pentium processors have
1324           a math coprocessor built in, 486SX and 386 do not, unless you added
1325           a 487DX or 387, respectively. (The messages during boot time can
1326           give you some hints here ["man dmesg"].) Everyone needs either a
1327           coprocessor or this emulation.
1328
1329           If you don't have a math coprocessor, you need to say Y here; if you
1330           say Y here even though you have a coprocessor, the coprocessor will
1331           be used nevertheless. (This behavior can be changed with the kernel
1332           command line option "no387", which comes handy if your coprocessor
1333           is broken. Try "man bootparam" or see the documentation of your boot
1334           loader (lilo or loadlin) about how to pass options to the kernel at
1335           boot time.) This means that it is a good idea to say Y here if you
1336           intend to use this kernel on different machines.
1337
1338           More information about the internals of the Linux math coprocessor
1339           emulation can be found in <file:arch/x86/math-emu/README>.
1340
1341           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1342           kernel, it won't hurt.
1343
1344 config MTRR
1345         bool "MTRR (Memory Type Range Register) support"
1346         ---help---
1347           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1348           the Memory Type Range Registers (MTRRs) may be used to control
1349           processor access to memory ranges. This is most useful if you have
1350           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1351           allows bus write transfers to be combined into a larger transfer
1352           before bursting over the PCI/AGP bus. This can increase performance
1353           of image write operations 2.5 times or more. Saying Y here creates a
1354           /proc/mtrr file which may be used to manipulate your processor's
1355           MTRRs. Typically the X server should use this.
1356
1357           This code has a reasonably generic interface so that similar
1358           control registers on other processors can be easily supported
1359           as well:
1360
1361           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1362           Registers (ARRs) which provide a similar functionality to MTRRs. For
1363           these, the ARRs are used to emulate the MTRRs.
1364           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1365           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1366           write-combining. All of these processors are supported by this code
1367           and it makes sense to say Y here if you have one of them.
1368
1369           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1370           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1371           can lead to all sorts of problems, so it's good to say Y here.
1372
1373           You can safely say Y even if your machine doesn't have MTRRs, you'll
1374           just add about 9 KB to your kernel.
1375
1376           See <file:Documentation/x86/mtrr.txt> for more information.
1377
1378 config MTRR_SANITIZER
1379         def_bool y
1380         prompt "MTRR cleanup support"
1381         depends on MTRR
1382         ---help---
1383           Convert MTRR layout from continuous to discrete, so X drivers can
1384           add writeback entries.
1385
1386           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1387           The largest mtrr entry size for a continuous block can be set with
1388           mtrr_chunk_size.
1389
1390           If unsure, say Y.
1391
1392 config MTRR_SANITIZER_ENABLE_DEFAULT
1393         int "MTRR cleanup enable value (0-1)"
1394         range 0 1
1395         default "0"
1396         depends on MTRR_SANITIZER
1397         ---help---
1398           Enable mtrr cleanup default value
1399
1400 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1401         int "MTRR cleanup spare reg num (0-7)"
1402         range 0 7
1403         default "1"
1404         depends on MTRR_SANITIZER
1405         ---help---
1406           mtrr cleanup spare entries default, it can be changed via
1407           mtrr_spare_reg_nr=N on the kernel command line.
1408
1409 config X86_PAT
1410         bool
1411         prompt "x86 PAT support"
1412         depends on MTRR
1413         ---help---
1414           Use PAT attributes to setup page level cache control.
1415
1416           PATs are the modern equivalents of MTRRs and are much more
1417           flexible than MTRRs.
1418
1419           Say N here if you see bootup problems (boot crash, boot hang,
1420           spontaneous reboots) or a non-working video driver.
1421
1422           If unsure, say Y.
1423
1424 config EFI
1425         bool "EFI runtime service support"
1426         depends on ACPI
1427         ---help---
1428           This enables the kernel to use EFI runtime services that are
1429           available (such as the EFI variable services).
1430
1431           This option is only useful on systems that have EFI firmware.
1432           In addition, you should use the latest ELILO loader available
1433           at <http://elilo.sourceforge.net> in order to take advantage
1434           of EFI runtime services. However, even with this option, the
1435           resultant kernel should continue to boot on existing non-EFI
1436           platforms.
1437
1438 config SECCOMP
1439         def_bool y
1440         prompt "Enable seccomp to safely compute untrusted bytecode"
1441         ---help---
1442           This kernel feature is useful for number crunching applications
1443           that may need to compute untrusted bytecode during their
1444           execution. By using pipes or other transports made available to
1445           the process as file descriptors supporting the read/write
1446           syscalls, it's possible to isolate those applications in
1447           their own address space using seccomp. Once seccomp is
1448           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1449           and the task is only allowed to execute a few safe syscalls
1450           defined by each seccomp mode.
1451
1452           If unsure, say Y. Only embedded should say N here.
1453
1454 config CC_STACKPROTECTOR_ALL
1455         bool
1456
1457 config CC_STACKPROTECTOR
1458         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1459         select CC_STACKPROTECTOR_ALL
1460         ---help---
1461           This option turns on the -fstack-protector GCC feature. This
1462           feature puts, at the beginning of functions, a canary value on
1463           the stack just before the return address, and validates
1464           the value just before actually returning.  Stack based buffer
1465           overflows (that need to overwrite this return address) now also
1466           overwrite the canary, which gets detected and the attack is then
1467           neutralized via a kernel panic.
1468
1469           This feature requires gcc version 4.2 or above, or a distribution
1470           gcc with the feature backported. Older versions are automatically
1471           detected and for those versions, this configuration option is
1472           ignored. (and a warning is printed during bootup)
1473
1474 source kernel/Kconfig.hz
1475
1476 config KEXEC
1477         bool "kexec system call"
1478         ---help---
1479           kexec is a system call that implements the ability to shutdown your
1480           current kernel, and to start another kernel.  It is like a reboot
1481           but it is independent of the system firmware.   And like a reboot
1482           you can start any kernel with it, not just Linux.
1483
1484           The name comes from the similarity to the exec system call.
1485
1486           It is an ongoing process to be certain the hardware in a machine
1487           is properly shutdown, so do not be surprised if this code does not
1488           initially work for you.  It may help to enable device hotplugging
1489           support.  As of this writing the exact hardware interface is
1490           strongly in flux, so no good recommendation can be made.
1491
1492 config CRASH_DUMP
1493         bool "kernel crash dumps"
1494         depends on X86_64 || (X86_32 && HIGHMEM)
1495         ---help---
1496           Generate crash dump after being started by kexec.
1497           This should be normally only set in special crash dump kernels
1498           which are loaded in the main kernel with kexec-tools into
1499           a specially reserved region and then later executed after
1500           a crash by kdump/kexec. The crash dump kernel must be compiled
1501           to a memory address not used by the main kernel or BIOS using
1502           PHYSICAL_START, or it must be built as a relocatable image
1503           (CONFIG_RELOCATABLE=y).
1504           For more details see Documentation/kdump/kdump.txt
1505
1506 config KEXEC_JUMP
1507         bool "kexec jump (EXPERIMENTAL)"
1508         depends on EXPERIMENTAL
1509         depends on KEXEC && HIBERNATION
1510         ---help---
1511           Jump between original kernel and kexeced kernel and invoke
1512           code in physical address mode via KEXEC
1513
1514 config PHYSICAL_START
1515         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1516         default "0x1000000"
1517         ---help---
1518           This gives the physical address where the kernel is loaded.
1519
1520           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1521           bzImage will decompress itself to above physical address and
1522           run from there. Otherwise, bzImage will run from the address where
1523           it has been loaded by the boot loader and will ignore above physical
1524           address.
1525
1526           In normal kdump cases one does not have to set/change this option
1527           as now bzImage can be compiled as a completely relocatable image
1528           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1529           address. This option is mainly useful for the folks who don't want
1530           to use a bzImage for capturing the crash dump and want to use a
1531           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1532           to be specifically compiled to run from a specific memory area
1533           (normally a reserved region) and this option comes handy.
1534
1535           So if you are using bzImage for capturing the crash dump,
1536           leave the value here unchanged to 0x1000000 and set
1537           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1538           for capturing the crash dump change this value to start of
1539           the reserved region.  In other words, it can be set based on
1540           the "X" value as specified in the "crashkernel=YM@XM"
1541           command line boot parameter passed to the panic-ed
1542           kernel. Please take a look at Documentation/kdump/kdump.txt
1543           for more details about crash dumps.
1544
1545           Usage of bzImage for capturing the crash dump is recommended as
1546           one does not have to build two kernels. Same kernel can be used
1547           as production kernel and capture kernel. Above option should have
1548           gone away after relocatable bzImage support is introduced. But it
1549           is present because there are users out there who continue to use
1550           vmlinux for dump capture. This option should go away down the
1551           line.
1552
1553           Don't change this unless you know what you are doing.
1554
1555 config RELOCATABLE
1556         bool "Build a relocatable kernel"
1557         default y
1558         ---help---
1559           This builds a kernel image that retains relocation information
1560           so it can be loaded someplace besides the default 1MB.
1561           The relocations tend to make the kernel binary about 10% larger,
1562           but are discarded at runtime.
1563
1564           One use is for the kexec on panic case where the recovery kernel
1565           must live at a different physical address than the primary
1566           kernel.
1567
1568           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1569           it has been loaded at and the compile time physical address
1570           (CONFIG_PHYSICAL_START) is ignored.
1571
1572 # Relocation on x86-32 needs some additional build support
1573 config X86_NEED_RELOCS
1574         def_bool y
1575         depends on X86_32 && RELOCATABLE
1576
1577 config PHYSICAL_ALIGN
1578         hex
1579         prompt "Alignment value to which kernel should be aligned" if X86_32
1580         default "0x1000000"
1581         range 0x2000 0x1000000
1582         ---help---
1583           This value puts the alignment restrictions on physical address
1584           where kernel is loaded and run from. Kernel is compiled for an
1585           address which meets above alignment restriction.
1586
1587           If bootloader loads the kernel at a non-aligned address and
1588           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1589           address aligned to above value and run from there.
1590
1591           If bootloader loads the kernel at a non-aligned address and
1592           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1593           load address and decompress itself to the address it has been
1594           compiled for and run from there. The address for which kernel is
1595           compiled already meets above alignment restrictions. Hence the
1596           end result is that kernel runs from a physical address meeting
1597           above alignment restrictions.
1598
1599           Don't change this unless you know what you are doing.
1600
1601 config HOTPLUG_CPU
1602         bool "Support for hot-pluggable CPUs"
1603         depends on SMP && HOTPLUG
1604         ---help---
1605           Say Y here to allow turning CPUs off and on. CPUs can be
1606           controlled through /sys/devices/system/cpu.
1607           ( Note: power management support will enable this option
1608             automatically on SMP systems. )
1609           Say N if you want to disable CPU hotplug.
1610
1611 config COMPAT_VDSO
1612         def_bool y
1613         prompt "Compat VDSO support"
1614         depends on X86_32 || IA32_EMULATION
1615         ---help---
1616           Map the 32-bit VDSO to the predictable old-style address too.
1617         ---help---
1618           Say N here if you are running a sufficiently recent glibc
1619           version (2.3.3 or later), to remove the high-mapped
1620           VDSO mapping and to exclusively use the randomized VDSO.
1621
1622           If unsure, say Y.
1623
1624 config CMDLINE_BOOL
1625         bool "Built-in kernel command line"
1626         default n
1627         ---help---
1628           Allow for specifying boot arguments to the kernel at
1629           build time.  On some systems (e.g. embedded ones), it is
1630           necessary or convenient to provide some or all of the
1631           kernel boot arguments with the kernel itself (that is,
1632           to not rely on the boot loader to provide them.)
1633
1634           To compile command line arguments into the kernel,
1635           set this option to 'Y', then fill in the
1636           the boot arguments in CONFIG_CMDLINE.
1637
1638           Systems with fully functional boot loaders (i.e. non-embedded)
1639           should leave this option set to 'N'.
1640
1641 config CMDLINE
1642         string "Built-in kernel command string"
1643         depends on CMDLINE_BOOL
1644         default ""
1645         ---help---
1646           Enter arguments here that should be compiled into the kernel
1647           image and used at boot time.  If the boot loader provides a
1648           command line at boot time, it is appended to this string to
1649           form the full kernel command line, when the system boots.
1650
1651           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1652           change this behavior.
1653
1654           In most cases, the command line (whether built-in or provided
1655           by the boot loader) should specify the device for the root
1656           file system.
1657
1658 config CMDLINE_OVERRIDE
1659         bool "Built-in command line overrides boot loader arguments"
1660         default n
1661         depends on CMDLINE_BOOL
1662         ---help---
1663           Set this option to 'Y' to have the kernel ignore the boot loader
1664           command line, and use ONLY the built-in command line.
1665
1666           This is used to work around broken boot loaders.  This should
1667           be set to 'N' under normal conditions.
1668
1669 endmenu
1670
1671 config ARCH_ENABLE_MEMORY_HOTPLUG
1672         def_bool y
1673         depends on X86_64 || (X86_32 && HIGHMEM)
1674
1675 config ARCH_ENABLE_MEMORY_HOTREMOVE
1676         def_bool y
1677         depends on MEMORY_HOTPLUG
1678
1679 config HAVE_ARCH_EARLY_PFN_TO_NID
1680         def_bool X86_64
1681         depends on NUMA
1682
1683 menu "Power management and ACPI options"
1684
1685 config ARCH_HIBERNATION_HEADER
1686         def_bool y
1687         depends on X86_64 && HIBERNATION
1688
1689 source "kernel/power/Kconfig"
1690
1691 source "drivers/acpi/Kconfig"
1692
1693 config X86_APM_BOOT
1694         bool
1695         default y
1696         depends on APM || APM_MODULE
1697
1698 menuconfig APM
1699         tristate "APM (Advanced Power Management) BIOS support"
1700         depends on X86_32 && PM_SLEEP
1701         ---help---
1702           APM is a BIOS specification for saving power using several different
1703           techniques. This is mostly useful for battery powered laptops with
1704           APM compliant BIOSes. If you say Y here, the system time will be
1705           reset after a RESUME operation, the /proc/apm device will provide
1706           battery status information, and user-space programs will receive
1707           notification of APM "events" (e.g. battery status change).
1708
1709           If you select "Y" here, you can disable actual use of the APM
1710           BIOS by passing the "apm=off" option to the kernel at boot time.
1711
1712           Note that the APM support is almost completely disabled for
1713           machines with more than one CPU.
1714
1715           In order to use APM, you will need supporting software. For location
1716           and more information, read <file:Documentation/power/pm.txt> and the
1717           Battery Powered Linux mini-HOWTO, available from
1718           <http://www.tldp.org/docs.html#howto>.
1719
1720           This driver does not spin down disk drives (see the hdparm(8)
1721           manpage ("man 8 hdparm") for that), and it doesn't turn off
1722           VESA-compliant "green" monitors.
1723
1724           This driver does not support the TI 4000M TravelMate and the ACER
1725           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1726           desktop machines also don't have compliant BIOSes, and this driver
1727           may cause those machines to panic during the boot phase.
1728
1729           Generally, if you don't have a battery in your machine, there isn't
1730           much point in using this driver and you should say N. If you get
1731           random kernel OOPSes or reboots that don't seem to be related to
1732           anything, try disabling/enabling this option (or disabling/enabling
1733           APM in your BIOS).
1734
1735           Some other things you should try when experiencing seemingly random,
1736           "weird" problems:
1737
1738           1) make sure that you have enough swap space and that it is
1739           enabled.
1740           2) pass the "no-hlt" option to the kernel
1741           3) switch on floating point emulation in the kernel and pass
1742           the "no387" option to the kernel
1743           4) pass the "floppy=nodma" option to the kernel
1744           5) pass the "mem=4M" option to the kernel (thereby disabling
1745           all but the first 4 MB of RAM)
1746           6) make sure that the CPU is not over clocked.
1747           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1748           8) disable the cache from your BIOS settings
1749           9) install a fan for the video card or exchange video RAM
1750           10) install a better fan for the CPU
1751           11) exchange RAM chips
1752           12) exchange the motherboard.
1753
1754           To compile this driver as a module, choose M here: the
1755           module will be called apm.
1756
1757 if APM
1758
1759 config APM_IGNORE_USER_SUSPEND
1760         bool "Ignore USER SUSPEND"
1761         ---help---
1762           This option will ignore USER SUSPEND requests. On machines with a
1763           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1764           series notebooks, it is necessary to say Y because of a BIOS bug.
1765
1766 config APM_DO_ENABLE
1767         bool "Enable PM at boot time"
1768         ---help---
1769           Enable APM features at boot time. From page 36 of the APM BIOS
1770           specification: "When disabled, the APM BIOS does not automatically
1771           power manage devices, enter the Standby State, enter the Suspend
1772           State, or take power saving steps in response to CPU Idle calls."
1773           This driver will make CPU Idle calls when Linux is idle (unless this
1774           feature is turned off -- see "Do CPU IDLE calls", below). This
1775           should always save battery power, but more complicated APM features
1776           will be dependent on your BIOS implementation. You may need to turn
1777           this option off if your computer hangs at boot time when using APM
1778           support, or if it beeps continuously instead of suspending. Turn
1779           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1780           T400CDT. This is off by default since most machines do fine without
1781           this feature.
1782
1783 config APM_CPU_IDLE
1784         bool "Make CPU Idle calls when idle"
1785         ---help---
1786           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1787           On some machines, this can activate improved power savings, such as
1788           a slowed CPU clock rate, when the machine is idle. These idle calls
1789           are made after the idle loop has run for some length of time (e.g.,
1790           333 mS). On some machines, this will cause a hang at boot time or
1791           whenever the CPU becomes idle. (On machines with more than one CPU,
1792           this option does nothing.)
1793
1794 config APM_DISPLAY_BLANK
1795         bool "Enable console blanking using APM"
1796         ---help---
1797           Enable console blanking using the APM. Some laptops can use this to
1798           turn off the LCD backlight when the screen blanker of the Linux
1799           virtual console blanks the screen. Note that this is only used by
1800           the virtual console screen blanker, and won't turn off the backlight
1801           when using the X Window system. This also doesn't have anything to
1802           do with your VESA-compliant power-saving monitor. Further, this
1803           option doesn't work for all laptops -- it might not turn off your
1804           backlight at all, or it might print a lot of errors to the console,
1805           especially if you are using gpm.
1806
1807 config APM_ALLOW_INTS
1808         bool "Allow interrupts during APM BIOS calls"
1809         ---help---
1810           Normally we disable external interrupts while we are making calls to
1811           the APM BIOS as a measure to lessen the effects of a badly behaving
1812           BIOS implementation.  The BIOS should reenable interrupts if it
1813           needs to.  Unfortunately, some BIOSes do not -- especially those in
1814           many of the newer IBM Thinkpads.  If you experience hangs when you
1815           suspend, try setting this to Y.  Otherwise, say N.
1816
1817 endif # APM
1818
1819 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1820
1821 source "drivers/cpuidle/Kconfig"
1822
1823 source "drivers/idle/Kconfig"
1824
1825 endmenu
1826
1827
1828 menu "Bus options (PCI etc.)"
1829
1830 config PCI
1831         bool "PCI support"
1832         default y
1833         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1834         ---help---
1835           Find out whether you have a PCI motherboard. PCI is the name of a
1836           bus system, i.e. the way the CPU talks to the other stuff inside
1837           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1838           VESA. If you have PCI, say Y, otherwise N.
1839
1840 choice
1841         prompt "PCI access mode"
1842         depends on X86_32 && PCI
1843         default PCI_GOANY
1844         ---help---
1845           On PCI systems, the BIOS can be used to detect the PCI devices and
1846           determine their configuration. However, some old PCI motherboards
1847           have BIOS bugs and may crash if this is done. Also, some embedded
1848           PCI-based systems don't have any BIOS at all. Linux can also try to
1849           detect the PCI hardware directly without using the BIOS.
1850
1851           With this option, you can specify how Linux should detect the
1852           PCI devices. If you choose "BIOS", the BIOS will be used,
1853           if you choose "Direct", the BIOS won't be used, and if you
1854           choose "MMConfig", then PCI Express MMCONFIG will be used.
1855           If you choose "Any", the kernel will try MMCONFIG, then the
1856           direct access method and falls back to the BIOS if that doesn't
1857           work. If unsure, go with the default, which is "Any".
1858
1859 config PCI_GOBIOS
1860         bool "BIOS"
1861
1862 config PCI_GOMMCONFIG
1863         bool "MMConfig"
1864
1865 config PCI_GODIRECT
1866         bool "Direct"
1867
1868 config PCI_GOOLPC
1869         bool "OLPC"
1870         depends on OLPC
1871
1872 config PCI_GOANY
1873         bool "Any"
1874
1875 endchoice
1876
1877 config PCI_BIOS
1878         def_bool y
1879         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1880
1881 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1882 config PCI_DIRECT
1883         def_bool y
1884         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1885
1886 config PCI_MMCONFIG
1887         def_bool y
1888         depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY)
1889
1890 config PCI_OLPC
1891         def_bool y
1892         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1893
1894 config PCI_DOMAINS
1895         def_bool y
1896         depends on PCI
1897
1898 config PCI_MMCONFIG
1899         bool "Support mmconfig PCI config space access"
1900         depends on X86_64 && PCI && ACPI
1901
1902 config DMAR
1903         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1904         depends on PCI_MSI && ACPI && EXPERIMENTAL
1905         help
1906           DMA remapping (DMAR) devices support enables independent address
1907           translations for Direct Memory Access (DMA) from devices.
1908           These DMA remapping devices are reported via ACPI tables
1909           and include PCI device scope covered by these DMA
1910           remapping devices.
1911
1912 config DMAR_DEFAULT_ON
1913         def_bool y
1914         prompt "Enable DMA Remapping Devices by default"
1915         depends on DMAR
1916         help
1917           Selecting this option will enable a DMAR device at boot time if
1918           one is found. If this option is not selected, DMAR support can
1919           be enabled by passing intel_iommu=on to the kernel. It is
1920           recommended you say N here while the DMAR code remains
1921           experimental.
1922
1923 config DMAR_BROKEN_GFX_WA
1924         def_bool n
1925         prompt "Workaround broken graphics drivers (going away soon)"
1926         depends on DMAR
1927         ---help---
1928           Current Graphics drivers tend to use physical address
1929           for DMA and avoid using DMA APIs. Setting this config
1930           option permits the IOMMU driver to set a unity map for
1931           all the OS-visible memory. Hence the driver can continue
1932           to use physical addresses for DMA, at least until this
1933           option is removed in the 2.6.32 kernel.
1934
1935 config DMAR_FLOPPY_WA
1936         def_bool y
1937         depends on DMAR
1938         ---help---
1939           Floppy disk drivers are known to bypass DMA API calls
1940           thereby failing to work when IOMMU is enabled. This
1941           workaround will setup a 1:1 mapping for the first
1942           16MiB to make floppy (an ISA device) work.
1943
1944 config INTR_REMAP
1945         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1946         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1947         ---help---
1948           Supports Interrupt remapping for IO-APIC and MSI devices.
1949           To use x2apic mode in the CPU's which support x2APIC enhancements or
1950           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1951
1952 source "drivers/pci/pcie/Kconfig"
1953
1954 source "drivers/pci/Kconfig"
1955
1956 # x86_64 have no ISA slots, but do have ISA-style DMA.
1957 config ISA_DMA_API
1958         def_bool y
1959
1960 if X86_32
1961
1962 config ISA
1963         bool "ISA support"
1964         ---help---
1965           Find out whether you have ISA slots on your motherboard.  ISA is the
1966           name of a bus system, i.e. the way the CPU talks to the other stuff
1967           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1968           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1969           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1970
1971 config EISA
1972         bool "EISA support"
1973         depends on ISA
1974         ---help---
1975           The Extended Industry Standard Architecture (EISA) bus was
1976           developed as an open alternative to the IBM MicroChannel bus.
1977
1978           The EISA bus provided some of the features of the IBM MicroChannel
1979           bus while maintaining backward compatibility with cards made for
1980           the older ISA bus.  The EISA bus saw limited use between 1988 and
1981           1995 when it was made obsolete by the PCI bus.
1982
1983           Say Y here if you are building a kernel for an EISA-based machine.
1984
1985           Otherwise, say N.
1986
1987 source "drivers/eisa/Kconfig"
1988
1989 config MCA
1990         bool "MCA support"
1991         ---help---
1992           MicroChannel Architecture is found in some IBM PS/2 machines and
1993           laptops.  It is a bus system similar to PCI or ISA. See
1994           <file:Documentation/mca.txt> (and especially the web page given
1995           there) before attempting to build an MCA bus kernel.
1996
1997 source "drivers/mca/Kconfig"
1998
1999 config SCx200
2000         tristate "NatSemi SCx200 support"
2001         ---help---
2002           This provides basic support for National Semiconductor's
2003           (now AMD's) Geode processors.  The driver probes for the
2004           PCI-IDs of several on-chip devices, so its a good dependency
2005           for other scx200_* drivers.
2006
2007           If compiled as a module, the driver is named scx200.
2008
2009 config SCx200HR_TIMER
2010         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2011         depends on SCx200 && GENERIC_TIME
2012         default y
2013         ---help---
2014           This driver provides a clocksource built upon the on-chip
2015           27MHz high-resolution timer.  Its also a workaround for
2016           NSC Geode SC-1100's buggy TSC, which loses time when the
2017           processor goes idle (as is done by the scheduler).  The
2018           other workaround is idle=poll boot option.
2019
2020 config GEODE_MFGPT_TIMER
2021         def_bool y
2022         prompt "Geode Multi-Function General Purpose Timer (MFGPT) events"
2023         depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS
2024         ---help---
2025           This driver provides a clock event source based on the MFGPT
2026           timer(s) in the CS5535 and CS5536 companion chip for the geode.
2027           MFGPTs have a better resolution and max interval than the
2028           generic PIT, and are suitable for use as high-res timers.
2029
2030 config OLPC
2031         bool "One Laptop Per Child support"
2032         default n
2033         ---help---
2034           Add support for detecting the unique features of the OLPC
2035           XO hardware.
2036
2037 endif # X86_32
2038
2039 config K8_NB
2040         def_bool y
2041         depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2042
2043 source "drivers/pcmcia/Kconfig"
2044
2045 source "drivers/pci/hotplug/Kconfig"
2046
2047 endmenu
2048
2049
2050 menu "Executable file formats / Emulations"
2051
2052 source "fs/Kconfig.binfmt"
2053
2054 config IA32_EMULATION
2055         bool "IA32 Emulation"
2056         depends on X86_64
2057         select COMPAT_BINFMT_ELF
2058         ---help---
2059           Include code to run 32-bit programs under a 64-bit kernel. You should
2060           likely turn this on, unless you're 100% sure that you don't have any
2061           32-bit programs left.
2062
2063 config IA32_AOUT
2064         tristate "IA32 a.out support"
2065         depends on IA32_EMULATION
2066         ---help---
2067           Support old a.out binaries in the 32bit emulation.
2068
2069 config COMPAT
2070         def_bool y
2071         depends on IA32_EMULATION
2072
2073 config COMPAT_FOR_U64_ALIGNMENT
2074         def_bool COMPAT
2075         depends on X86_64
2076
2077 config SYSVIPC_COMPAT
2078         def_bool y
2079         depends on COMPAT && SYSVIPC
2080
2081 endmenu
2082
2083
2084 config HAVE_ATOMIC_IOMAP
2085         def_bool y
2086         depends on X86_32
2087
2088 source "net/Kconfig"
2089
2090 source "drivers/Kconfig"
2091
2092 source "drivers/firmware/Kconfig"
2093
2094 source "fs/Kconfig"
2095
2096 source "arch/x86/Kconfig.debug"
2097
2098 source "security/Kconfig"
2099
2100 source "crypto/Kconfig"
2101
2102 source "arch/x86/kvm/Kconfig"
2103
2104 source "lib/Kconfig"