arch/x86/Kconfig

   1 # x86 configuration
   2 mainmenu "Linux Kernel Configuration for x86"
   3
   4 # Select 32 or 64 bit
   5 config 64BIT
   6         bool "64-bit kernel" if ARCH = "x86"
   7         default ARCH = "x86_64"
   8         ---help---
   9           Say yes to build a 64-bit kernel - formerly known as x86_64
  10           Say no to build a 32-bit kernel - formerly known as i386
  11
  12 config X86_32
  13         def_bool !64BIT
  14
  15 config X86_64
  16         def_bool 64BIT
  17
  18 ### Arch settings
  19 config X86
  20         def_bool y
  21         select HAVE_AOUT if X86_32
  22         select HAVE_READQ
  23         select HAVE_WRITEQ
  24         select HAVE_UNSTABLE_SCHED_CLOCK
  25         select HAVE_IDE
  26         select HAVE_OPROFILE
  27         select HAVE_PERF_EVENTS if (!M386 && !M486)
  28         select HAVE_IOREMAP_PROT
  29         select HAVE_KPROBES
  30         select ARCH_WANT_OPTIONAL_GPIOLIB
  31         select ARCH_WANT_FRAME_POINTERS
  32         select HAVE_DMA_ATTRS
  33         select HAVE_KRETPROBES
  34         select HAVE_OPTPROBES
  35         select HAVE_FTRACE_MCOUNT_RECORD
  36         select HAVE_DYNAMIC_FTRACE
  37         select HAVE_FUNCTION_TRACER
  38         select HAVE_FUNCTION_GRAPH_TRACER
  39         select HAVE_FUNCTION_GRAPH_FP_TEST
  40         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  41         select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  42         select HAVE_SYSCALL_TRACEPOINTS
  43         select HAVE_KVM
  44         select HAVE_ARCH_KGDB
  45         select HAVE_ARCH_TRACEHOOK
  46         select HAVE_GENERIC_DMA_COHERENT if X86_32
  47         select HAVE_EFFICIENT_UNALIGNED_ACCESS
  48         select USER_STACKTRACE_SUPPORT
  49         select HAVE_REGS_AND_STACK_ACCESS_API
  50         select HAVE_DMA_API_DEBUG
  51         select HAVE_KERNEL_GZIP
  52         select HAVE_KERNEL_BZIP2
  53         select HAVE_KERNEL_LZMA
  54         select HAVE_KERNEL_LZO
  55         select HAVE_HW_BREAKPOINT
  56         select PERF_EVENTS
  57         select ANON_INODES
  58         select HAVE_ARCH_KMEMCHECK
  59         select HAVE_USER_RETURN_NOTIFIER
  60
  61 config OUTPUT_FORMAT
  62         string
  63         default "elf32-i386" if X86_32
  64         default "elf64-x86-64" if X86_64
  65
  66 config ARCH_DEFCONFIG
  67         string
  68         default "arch/x86/configs/i386_defconfig" if X86_32
  69         default "arch/x86/configs/x86_64_defconfig" if X86_64
  70
  71 config GENERIC_TIME
  72         def_bool y
  73
  74 config GENERIC_CMOS_UPDATE
  75         def_bool y
  76
  77 config CLOCKSOURCE_WATCHDOG
  78         def_bool y
  79
  80 config GENERIC_CLOCKEVENTS
  81         def_bool y
  82
  83 config GENERIC_CLOCKEVENTS_BROADCAST
  84         def_bool y
  85         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  86
  87 config LOCKDEP_SUPPORT
  88         def_bool y
  89
  90 config STACKTRACE_SUPPORT
  91         def_bool y
  92
  93 config HAVE_LATENCYTOP_SUPPORT
  94         def_bool y
  95
  96 config MMU
  97         def_bool y
  98
  99 config ZONE_DMA
 100         def_bool y
 101
 102 config SBUS
 103         bool
 104
 105 config GENERIC_ISA_DMA
 106         def_bool y
 107
 108 config GENERIC_IOMAP
 109         def_bool y
 110
 111 config GENERIC_BUG
 112         def_bool y
 113         depends on BUG
 114         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 115
 116 config GENERIC_BUG_RELATIVE_POINTERS
 117         bool
 118
 119 config GENERIC_HWEIGHT
 120         def_bool y
 121
 122 config GENERIC_GPIO
 123         bool
 124
 125 config ARCH_MAY_HAVE_PC_FDC
 126         def_bool y
 127
 128 config RWSEM_GENERIC_SPINLOCK
 129         def_bool !X86_XADD
 130
 131 config RWSEM_XCHGADD_ALGORITHM
 132         def_bool X86_XADD
 133
 134 config ARCH_HAS_CPU_IDLE_WAIT
 135         def_bool y
 136
 137 config GENERIC_CALIBRATE_DELAY
 138         def_bool y
 139
 140 config GENERIC_TIME_VSYSCALL
 141         bool
 142         default X86_64
 143
 144 config ARCH_HAS_CPU_RELAX
 145         def_bool y
 146
 147 config ARCH_HAS_DEFAULT_IDLE
 148         def_bool y
 149
 150 config ARCH_HAS_CACHE_LINE_SIZE
 151         def_bool y
 152
 153 config HAVE_SETUP_PER_CPU_AREA
 154         def_bool y
 155
 156 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 157         def_bool y
 158
 159 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 160         def_bool y
 161
 162 config HAVE_CPUMASK_OF_CPU_MAP
 163         def_bool X86_64_SMP
 164
 165 config ARCH_HIBERNATION_POSSIBLE
 166         def_bool y
 167
 168 config ARCH_SUSPEND_POSSIBLE
 169         def_bool y
 170
 171 config ZONE_DMA32
 172         bool
 173         default X86_64
 174
 175 config ARCH_POPULATES_NODE_MAP
 176         def_bool y
 177
 178 config AUDIT_ARCH
 179         bool
 180         default X86_64
 181
 182 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 183         def_bool y
 184
 185 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 186         def_bool y
 187
 188 config HAVE_EARLY_RES
 189         def_bool y
 190
 191 config HAVE_INTEL_TXT
 192         def_bool y
 193         depends on EXPERIMENTAL && DMAR && ACPI
 194
 195 # Use the generic interrupt handling code in kernel/irq/:
 196 config GENERIC_HARDIRQS
 197         bool
 198         default y
 199
 200 config GENERIC_HARDIRQS_NO__DO_IRQ
 201        def_bool y
 202
 203 config GENERIC_IRQ_PROBE
 204         bool
 205         default y
 206
 207 config GENERIC_PENDING_IRQ
 208         bool
 209         depends on GENERIC_HARDIRQS && SMP
 210         default y
 211
 212 config USE_GENERIC_SMP_HELPERS
 213         def_bool y
 214         depends on SMP
 215
 216 config X86_32_SMP
 217         def_bool y
 218         depends on X86_32 && SMP
 219
 220 config X86_64_SMP
 221         def_bool y
 222         depends on X86_64 && SMP
 223
 224 config X86_HT
 225         bool
 226         depends on SMP
 227         default y
 228
 229 config X86_TRAMPOLINE
 230         bool
 231         depends on SMP || (64BIT && ACPI_SLEEP)
 232         default y
 233
 234 config X86_32_LAZY_GS
 235         def_bool y
 236         depends on X86_32 && !CC_STACKPROTECTOR
 237
 238 config KTIME_SCALAR
 239         def_bool X86_32
 240 source "init/Kconfig"
 241 source "kernel/Kconfig.freezer"
 242
 243 menu "Processor type and features"
 244
 245 source "kernel/time/Kconfig"
 246
 247 config SMP
 248         bool "Symmetric multi-processing support"
 249         ---help---
 250           This enables support for systems with more than one CPU. If you have
 251           a system with only one CPU, like most personal computers, say N. If
 252           you have a system with more than one CPU, say Y.
 253
 254           If you say N here, the kernel will run on single and multiprocessor
 255           machines, but will use only one CPU of a multiprocessor machine. If
 256           you say Y here, the kernel will run on many, but not all,
 257           singleprocessor machines. On a singleprocessor machine, the kernel
 258           will run faster if you say N here.
 259
 260           Note that if you say Y here and choose architecture "586" or
 261           "Pentium" under "Processor family", the kernel will not work on 486
 262           architectures. Similarly, multiprocessor kernels for the "PPro"
 263           architecture may not work on all Pentium based boards.
 264
 265           People using multiprocessor machines who say Y here should also say
 266           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 267           Management" code will be disabled if you say Y here.
 268
 269           See also <file:Documentation/i386/IO-APIC.txt>,
 270           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 271           <http://www.tldp.org/docs.html#howto>.
 272
 273           If you don't know what to do here, say N.
 274
 275 config X86_X2APIC
 276         bool "Support x2apic"
 277         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 278         ---help---
 279           This enables x2apic support on CPUs that have this feature.
 280
 281           This allows 32-bit apic IDs (so it can support very large systems),
 282           and accesses the local apic via MSRs not via mmio.
 283
 284           If you don't know what to do here, say N.
 285
 286 config SPARSE_IRQ
 287         bool "Support sparse irq numbering"
 288         depends on PCI_MSI || HT_IRQ
 289         ---help---
 290           This enables support for sparse irqs. This is useful for distro
 291           kernels that want to define a high CONFIG_NR_CPUS value but still
 292           want to have low kernel memory footprint on smaller machines.
 293
 294           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 295             out the irq_desc[] array in a more NUMA-friendly way. )
 296
 297           If you don't know what to do here, say N.
 298
 299 config NUMA_IRQ_DESC
 300         def_bool y
 301         depends on SPARSE_IRQ && NUMA
 302
 303 config X86_MPPARSE
 304         bool "Enable MPS table" if ACPI
 305         default y
 306         depends on X86_LOCAL_APIC
 307         ---help---
 308           For old smp systems that do not have proper acpi support. Newer systems
 309           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 310
 311 config X86_BIGSMP
 312         bool "Support for big SMP systems with more than 8 CPUs"
 313         depends on X86_32 && SMP
 314         ---help---
 315           This option is needed for the systems that have more than 8 CPUs
 316
 317 if X86_32
 318 config X86_EXTENDED_PLATFORM
 319         bool "Support for extended (non-PC) x86 platforms"
 320         default y
 321         ---help---
 322           If you disable this option then the kernel will only support
 323           standard PC platforms. (which covers the vast majority of
 324           systems out there.)
 325
 326           If you enable this option then you'll be able to select support
 327           for the following (non-PC) 32 bit x86 platforms:
 328                 AMD Elan
 329                 NUMAQ (IBM/Sequent)
 330                 RDC R-321x SoC
 331                 SGI 320/540 (Visual Workstation)
 332                 Summit/EXA (IBM x440)
 333                 Unisys ES7000 IA32 series
 334                 Moorestown MID devices
 335
 336           If you have one of these systems, or if you want to build a
 337           generic distribution kernel, say Y here - otherwise say N.
 338 endif
 339
 340 if X86_64
 341 config X86_EXTENDED_PLATFORM
 342         bool "Support for extended (non-PC) x86 platforms"
 343         default y
 344         ---help---
 345           If you disable this option then the kernel will only support
 346           standard PC platforms. (which covers the vast majority of
 347           systems out there.)
 348
 349           If you enable this option then you'll be able to select support
 350           for the following (non-PC) 64 bit x86 platforms:
 351                 ScaleMP vSMP
 352                 SGI Ultraviolet
 353
 354           If you have one of these systems, or if you want to build a
 355           generic distribution kernel, say Y here - otherwise say N.
 356 endif
 357 # This is an alphabetically sorted list of 64 bit extended platforms
 358 # Please maintain the alphabetic order if and when there are additions
 359
 360 config X86_VSMP
 361         bool "ScaleMP vSMP"
 362         select PARAVIRT
 363         depends on X86_64 && PCI
 364         depends on X86_EXTENDED_PLATFORM
 365         ---help---
 366           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 367           supposed to run on these EM64T-based machines.  Only choose this option
 368           if you have one of these machines.
 369
 370 config X86_UV
 371         bool "SGI Ultraviolet"
 372         depends on X86_64
 373         depends on X86_EXTENDED_PLATFORM
 374         depends on NUMA
 375         depends on X86_X2APIC
 376         ---help---
 377           This option is needed in order to support SGI Ultraviolet systems.
 378           If you don't have one of these, you should say N here.
 379
 380 # Following is an alphabetically sorted list of 32 bit extended platforms
 381 # Please maintain the alphabetic order if and when there are additions
 382
 383 config X86_ELAN
 384         bool "AMD Elan"
 385         depends on X86_32
 386         depends on X86_EXTENDED_PLATFORM
 387         ---help---
 388           Select this for an AMD Elan processor.
 389
 390           Do not use this option for K6/Athlon/Opteron processors!
 391
 392           If unsure, choose "PC-compatible" instead.
 393
 394 config X86_MRST
 395        bool "Moorestown MID platform"
 396         depends on PCI
 397         depends on PCI_GOANY
 398         depends on X86_32
 399         depends on X86_EXTENDED_PLATFORM
 400         depends on X86_IO_APIC
 401         select APB_TIMER
 402         ---help---
 403           Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 404           Internet Device(MID) platform. Moorestown consists of two chips:
 405           Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
 406           Unlike standard x86 PCs, Moorestown does not have many legacy devices
 407           nor standard legacy replacement devices/features. e.g. Moorestown does
 408           not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
 409
 410 config X86_RDC321X
 411         bool "RDC R-321x SoC"
 412         depends on X86_32
 413         depends on X86_EXTENDED_PLATFORM
 414         select M486
 415         select X86_REBOOTFIXUPS
 416         ---help---
 417           This option is needed for RDC R-321x system-on-chip, also known
 418           as R-8610-(G).
 419           If you don't have one of these chips, you should say N here.
 420
 421 config X86_32_NON_STANDARD
 422         bool "Support non-standard 32-bit SMP architectures"
 423         depends on X86_32 && SMP
 424         depends on X86_EXTENDED_PLATFORM
 425         ---help---
 426           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 427           subarchitectures.  It is intended for a generic binary kernel.
 428           if you select them all, kernel will probe it one by one. and will
 429           fallback to default.
 430
 431 # Alphabetically sorted list of Non standard 32 bit platforms
 432
 433 config X86_NUMAQ
 434         bool "NUMAQ (IBM/Sequent)"
 435         depends on X86_32_NON_STANDARD
 436         depends on PCI
 437         select NUMA
 438         select X86_MPPARSE
 439         ---help---
 440           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 441           NUMA multiquad box. This changes the way that processors are
 442           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 443           of Flat Logical.  You will need a new lynxer.elf file to flash your
 444           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 445
 446 config X86_SUPPORTS_MEMORY_FAILURE
 447         bool
 448         # MCE code calls memory_failure():
 449         depends on X86_MCE
 450         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
 451         depends on !X86_NUMAQ
 452         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
 453         depends on X86_64 || !SPARSEMEM
 454         select ARCH_SUPPORTS_MEMORY_FAILURE
 455         default y
 456
 457 config X86_VISWS
 458         bool "SGI 320/540 (Visual Workstation)"
 459         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 460         depends on X86_32_NON_STANDARD
 461         ---help---
 462           The SGI Visual Workstation series is an IA32-based workstation
 463           based on SGI systems chips with some legacy PC hardware attached.
 464
 465           Say Y here to create a kernel to run on the SGI 320 or 540.
 466
 467           A kernel compiled for the Visual Workstation will run on general
 468           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 469
 470 config X86_SUMMIT
 471         bool "Summit/EXA (IBM x440)"
 472         depends on X86_32_NON_STANDARD
 473         ---help---
 474           This option is needed for IBM systems that use the Summit/EXA chipset.
 475           In particular, it is needed for the x440.
 476
 477 config X86_ES7000
 478         bool "Unisys ES7000 IA32 series"
 479         depends on X86_32_NON_STANDARD && X86_BIGSMP
 480         ---help---
 481           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 482           supposed to run on an IA32-based Unisys ES7000 system.
 483
 484 config SCHED_OMIT_FRAME_POINTER
 485         def_bool y
 486         prompt "Single-depth WCHAN output"
 487         depends on X86
 488         ---help---
 489           Calculate simpler /proc/<PID>/wchan values. If this option
 490           is disabled then wchan values will recurse back to the
 491           caller function. This provides more accurate wchan values,
 492           at the expense of slightly more scheduling overhead.
 493
 494           If in doubt, say "Y".
 495
 496 menuconfig PARAVIRT_GUEST
 497         bool "Paravirtualized guest support"
 498         ---help---
 499           Say Y here to get to see options related to running Linux under
 500           various hypervisors.  This option alone does not add any kernel code.
 501
 502           If you say N, all options in this submenu will be skipped and disabled.
 503
 504 if PARAVIRT_GUEST
 505
 506 source "arch/x86/xen/Kconfig"
 507
 508 config VMI
 509         bool "VMI Guest support (DEPRECATED)"
 510         select PARAVIRT
 511         depends on X86_32
 512         ---help---
 513           VMI provides a paravirtualized interface to the VMware ESX server
 514           (it could be used by other hypervisors in theory too, but is not
 515           at the moment), by linking the kernel to a GPL-ed ROM module
 516           provided by the hypervisor.
 517
 518           As of September 2009, VMware has started a phased retirement
 519           of this feature from VMware's products. Please see
 520           feature-removal-schedule.txt for details.  If you are
 521           planning to enable this option, please note that you cannot
 522           live migrate a VMI enabled VM to a future VMware product,
 523           which doesn't support VMI. So if you expect your kernel to
 524           seamlessly migrate to newer VMware products, keep this
 525           disabled.
 526
 527 config KVM_CLOCK
 528         bool "KVM paravirtualized clock"
 529         select PARAVIRT
 530         select PARAVIRT_CLOCK
 531         ---help---
 532           Turning on this option will allow you to run a paravirtualized clock
 533           when running over the KVM hypervisor. Instead of relying on a PIT
 534           (or probably other) emulation by the underlying device model, the host
 535           provides the guest with timing infrastructure such as time of day, and
 536           system time
 537
 538 config KVM_GUEST
 539         bool "KVM Guest support"
 540         select PARAVIRT
 541         ---help---
 542           This option enables various optimizations for running under the KVM
 543           hypervisor.
 544
 545 source "arch/x86/lguest/Kconfig"
 546
 547 config PARAVIRT
 548         bool "Enable paravirtualization code"
 549         ---help---
 550           This changes the kernel so it can modify itself when it is run
 551           under a hypervisor, potentially improving performance significantly
 552           over full virtualization.  However, when run without a hypervisor
 553           the kernel is theoretically slower and slightly larger.
 554
 555 config PARAVIRT_SPINLOCKS
 556         bool "Paravirtualization layer for spinlocks"
 557         depends on PARAVIRT && SMP && EXPERIMENTAL
 558         ---help---
 559           Paravirtualized spinlocks allow a pvops backend to replace the
 560           spinlock implementation with something virtualization-friendly
 561           (for example, block the virtual CPU rather than spinning).
 562
 563           Unfortunately the downside is an up to 5% performance hit on
 564           native kernels, with various workloads.
 565
 566           If you are unsure how to answer this question, answer N.
 567
 568 config PARAVIRT_CLOCK
 569         bool
 570         default n
 571
 572 endif
 573
 574 config PARAVIRT_DEBUG
 575         bool "paravirt-ops debugging"
 576         depends on PARAVIRT && DEBUG_KERNEL
 577         ---help---
 578           Enable to debug paravirt_ops internals.  Specifically, BUG if
 579           a paravirt_op is missing when it is called.
 580
 581 config NO_BOOTMEM
 582         default y
 583         bool "Disable Bootmem code"
 584         ---help---
 585           Use early_res directly instead of bootmem before slab is ready.
 586                 - allocator (buddy) [generic]
 587                 - early allocator (bootmem) [generic]
 588                 - very early allocator (reserve_early*()) [x86]
 589                 - very very early allocator (early brk model) [x86]
 590           So reduce one layer between early allocator to final allocator
 591
 592
 593 config MEMTEST
 594         bool "Memtest"
 595         ---help---
 596           This option adds a kernel parameter 'memtest', which allows memtest
 597           to be set.
 598                 memtest=0, mean disabled; -- default
 599                 memtest=1, mean do 1 test pattern;
 600                 ...
 601                 memtest=4, mean do 4 test patterns.
 602           If you are unsure how to answer this question, answer N.
 603
 604 config X86_SUMMIT_NUMA
 605         def_bool y
 606         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 607
 608 config X86_CYCLONE_TIMER
 609         def_bool y
 610         depends on X86_32_NON_STANDARD
 611
 612 source "arch/x86/Kconfig.cpu"
 613
 614 config HPET_TIMER
 615         def_bool X86_64
 616         prompt "HPET Timer Support" if X86_32
 617         ---help---
 618           Use the IA-PC HPET (High Precision Event Timer) to manage
 619           time in preference to the PIT and RTC, if a HPET is
 620           present.
 621           HPET is the next generation timer replacing legacy 8254s.
 622           The HPET provides a stable time base on SMP
 623           systems, unlike the TSC, but it is more expensive to access,
 624           as it is off-chip.  You can find the HPET spec at
 625           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 626
 627           You can safely choose Y here.  However, HPET will only be
 628           activated if the platform and the BIOS support this feature.
 629           Otherwise the 8254 will be used for timing services.
 630
 631           Choose N to continue using the legacy 8254 timer.
 632
 633 config HPET_EMULATE_RTC
 634         def_bool y
 635         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 636
 637 config APB_TIMER
 638        def_bool y if MRST
 639        prompt "Langwell APB Timer Support" if X86_MRST
 640        help
 641          APB timer is the replacement for 8254, HPET on X86 MID platforms.
 642          The APBT provides a stable time base on SMP
 643          systems, unlike the TSC, but it is more expensive to access,
 644          as it is off-chip. APB timers are always running regardless of CPU
 645          C states, they are used as per CPU clockevent device when possible.
 646
 647 # Mark as embedded because too many people got it wrong.
 648 # The code disables itself when not needed.
 649 config DMI
 650         default y
 651         bool "Enable DMI scanning" if EMBEDDED
 652         ---help---
 653           Enabled scanning of DMI to identify machine quirks. Say Y
 654           here unless you have verified that your setup is not
 655           affected by entries in the DMI blacklist. Required by PNP
 656           BIOS code.
 657
 658 config GART_IOMMU
 659         bool "GART IOMMU support" if EMBEDDED
 660         default y
 661         select SWIOTLB
 662         depends on X86_64 && PCI
 663         ---help---
 664           Support for full DMA access of devices with 32bit memory access only
 665           on systems with more than 3GB. This is usually needed for USB,
 666           sound, many IDE/SATA chipsets and some other devices.
 667           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 668           based hardware IOMMU and a software bounce buffer based IOMMU used
 669           on Intel systems and as fallback.
 670           The code is only active when needed (enough memory and limited
 671           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 672           too.
 673
 674 config CALGARY_IOMMU
 675         bool "IBM Calgary IOMMU support"
 676         select SWIOTLB
 677         depends on X86_64 && PCI && EXPERIMENTAL
 678         ---help---
 679           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 680           systems. Needed to run systems with more than 3GB of memory
 681           properly with 32-bit PCI devices that do not support DAC
 682           (Double Address Cycle). Calgary also supports bus level
 683           isolation, where all DMAs pass through the IOMMU.  This
 684           prevents them from going anywhere except their intended
 685           destination. This catches hard-to-find kernel bugs and
 686           mis-behaving drivers and devices that do not use the DMA-API
 687           properly to set up their DMA buffers.  The IOMMU can be
 688           turned off at boot time with the iommu=off parameter.
 689           Normally the kernel will make the right choice by itself.
 690           If unsure, say Y.
 691
 692 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 693         def_bool y
 694         prompt "Should Calgary be enabled by default?"
 695         depends on CALGARY_IOMMU
 696         ---help---
 697           Should Calgary be enabled by default? if you choose 'y', Calgary
 698           will be used (if it exists). If you choose 'n', Calgary will not be
 699           used even if it exists. If you choose 'n' and would like to use
 700           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 701           If unsure, say Y.
 702
 703 config AMD_IOMMU
 704         bool "AMD IOMMU support"
 705         select SWIOTLB
 706         select PCI_MSI
 707         depends on X86_64 && PCI && ACPI
 708         ---help---
 709           With this option you can enable support for AMD IOMMU hardware in
 710           your system. An IOMMU is a hardware component which provides
 711           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 712           can isolate the the DMA memory of different devices and protect the
 713           system from misbehaving device drivers or hardware.
 714
 715           You can find out if your system has an AMD IOMMU if you look into
 716           your BIOS for an option to enable it or if you have an IVRS ACPI
 717           table.
 718
 719 config AMD_IOMMU_STATS
 720         bool "Export AMD IOMMU statistics to debugfs"
 721         depends on AMD_IOMMU
 722         select DEBUG_FS
 723         ---help---
 724           This option enables code in the AMD IOMMU driver to collect various
 725           statistics about whats happening in the driver and exports that
 726           information to userspace via debugfs.
 727           If unsure, say N.
 728
 729 # need this always selected by IOMMU for the VIA workaround
 730 config SWIOTLB
 731         def_bool y if X86_64
 732         ---help---
 733           Support for software bounce buffers used on x86-64 systems
 734           which don't have a hardware IOMMU (e.g. the current generation
 735           of Intel's x86-64 CPUs). Using this PCI devices which can only
 736           access 32-bits of memory can be used on systems with more than
 737           3 GB of memory. If unsure, say Y.
 738
 739 config IOMMU_HELPER
 740         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 741
 742 config IOMMU_API
 743         def_bool (AMD_IOMMU || DMAR)
 744
 745 config MAXSMP
 746         bool "Configure Maximum number of SMP Processors and NUMA Nodes"
 747         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 748         select CPUMASK_OFFSTACK
 749         default n
 750         ---help---
 751           Configure maximum number of CPUS and NUMA Nodes for this architecture.
 752           If unsure, say N.
 753
 754 config NR_CPUS
 755         int "Maximum number of CPUs" if SMP && !MAXSMP
 756         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 757         range 2 512 if SMP && !MAXSMP
 758         default "1" if !SMP
 759         default "4096" if MAXSMP
 760         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 761         default "8" if SMP
 762         ---help---
 763           This allows you to specify the maximum number of CPUs which this
 764           kernel will support.  The maximum supported value is 512 and the
 765           minimum value which makes sense is 2.
 766
 767           This is purely to save memory - each supported CPU adds
 768           approximately eight kilobytes to the kernel image.
 769
 770 config SCHED_SMT
 771         bool "SMT (Hyperthreading) scheduler support"
 772         depends on X86_HT
 773         ---help---
 774           SMT scheduler support improves the CPU scheduler's decision making
 775           when dealing with Intel Pentium 4 chips with HyperThreading at a
 776           cost of slightly increased overhead in some places. If unsure say
 777           N here.
 778
 779 config SCHED_MC
 780         def_bool y
 781         prompt "Multi-core scheduler support"
 782         depends on X86_HT
 783         ---help---
 784           Multi-core scheduler support improves the CPU scheduler's decision
 785           making when dealing with multi-core CPU chips at a cost of slightly
 786           increased overhead in some places. If unsure say N here.
 787
 788 source "kernel/Kconfig.preempt"
 789
 790 config X86_UP_APIC
 791         bool "Local APIC support on uniprocessors"
 792         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 793         ---help---
 794           A local APIC (Advanced Programmable Interrupt Controller) is an
 795           integrated interrupt controller in the CPU. If you have a single-CPU
 796           system which has a processor with a local APIC, you can say Y here to
 797           enable and use it. If you say Y here even though your machine doesn't
 798           have a local APIC, then the kernel will still run with no slowdown at
 799           all. The local APIC supports CPU-generated self-interrupts (timer,
 800           performance counters), and the NMI watchdog which detects hard
 801           lockups.
 802
 803 config X86_UP_IOAPIC
 804         bool "IO-APIC support on uniprocessors"
 805         depends on X86_UP_APIC
 806         ---help---
 807           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 808           SMP-capable replacement for PC-style interrupt controllers. Most
 809           SMP systems and many recent uniprocessor systems have one.
 810
 811           If you have a single-CPU system with an IO-APIC, you can say Y here
 812           to use it. If you say Y here even though your machine doesn't have
 813           an IO-APIC, then the kernel will still run with no slowdown at all.
 814
 815 config X86_LOCAL_APIC
 816         def_bool y
 817         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 818
 819 config X86_IO_APIC
 820         def_bool y
 821         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 822
 823 config X86_VISWS_APIC
 824         def_bool y
 825         depends on X86_32 && X86_VISWS
 826
 827 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 828         bool "Reroute for broken boot IRQs"
 829         default n
 830         depends on X86_IO_APIC
 831         ---help---
 832           This option enables a workaround that fixes a source of
 833           spurious interrupts. This is recommended when threaded
 834           interrupt handling is used on systems where the generation of
 835           superfluous "boot interrupts" cannot be disabled.
 836
 837           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 838           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 839           kernel does during interrupt handling). On chipsets where this
 840           boot IRQ generation cannot be disabled, this workaround keeps
 841           the original IRQ line masked so that only the equivalent "boot
 842           IRQ" is delivered to the CPUs. The workaround also tells the
 843           kernel to set up the IRQ handler on the boot IRQ line. In this
 844           way only one interrupt is delivered to the kernel. Otherwise
 845           the spurious second interrupt may cause the kernel to bring
 846           down (vital) interrupt lines.
 847
 848           Only affects "broken" chipsets. Interrupt sharing may be
 849           increased on these systems.
 850
 851 config X86_MCE
 852         bool "Machine Check / overheating reporting"
 853         ---help---
 854           Machine Check support allows the processor to notify the
 855           kernel if it detects a problem (e.g. overheating, data corruption).
 856           The action the kernel takes depends on the severity of the problem,
 857           ranging from warning messages to halting the machine.
 858
 859 config X86_MCE_INTEL
 860         def_bool y
 861         prompt "Intel MCE features"
 862         depends on X86_MCE && X86_LOCAL_APIC
 863         ---help---
 864            Additional support for intel specific MCE features such as
 865            the thermal monitor.
 866
 867 config X86_MCE_AMD
 868         def_bool y
 869         prompt "AMD MCE features"
 870         depends on X86_MCE && X86_LOCAL_APIC
 871         ---help---
 872            Additional support for AMD specific MCE features such as
 873            the DRAM Error Threshold.
 874
 875 config X86_ANCIENT_MCE
 876         def_bool n
 877         depends on X86_32 && X86_MCE
 878         prompt "Support for old Pentium 5 / WinChip machine checks"
 879         ---help---
 880           Include support for machine check handling on old Pentium 5 or WinChip
 881           systems. These typically need to be enabled explicitely on the command
 882           line.
 883
 884 config X86_MCE_THRESHOLD
 885         depends on X86_MCE_AMD || X86_MCE_INTEL
 886         bool
 887         default y
 888
 889 config X86_MCE_INJECT
 890         depends on X86_MCE
 891         tristate "Machine check injector support"
 892         ---help---
 893           Provide support for injecting machine checks for testing purposes.
 894           If you don't know what a machine check is and you don't do kernel
 895           QA it is safe to say n.
 896
 897 config X86_THERMAL_VECTOR
 898         def_bool y
 899         depends on X86_MCE_INTEL
 900
 901 config VM86
 902         bool "Enable VM86 support" if EMBEDDED
 903         default y
 904         depends on X86_32
 905         ---help---
 906           This option is required by programs like DOSEMU to run 16-bit legacy
 907           code on X86 processors. It also may be needed by software like
 908           XFree86 to initialize some video cards via BIOS. Disabling this
 909           option saves about 6k.
 910
 911 config TOSHIBA
 912         tristate "Toshiba Laptop support"
 913         depends on X86_32
 914         ---help---
 915           This adds a driver to safely access the System Management Mode of
 916           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 917           not work on models with a Phoenix BIOS. The System Management Mode
 918           is used to set the BIOS and power saving options on Toshiba portables.
 919
 920           For information on utilities to make use of this driver see the
 921           Toshiba Linux utilities web site at:
 922           <http://www.buzzard.org.uk/toshiba/>.
 923
 924           Say Y if you intend to run this kernel on a Toshiba portable.
 925           Say N otherwise.
 926
 927 config I8K
 928         tristate "Dell laptop support"
 929         ---help---
 930           This adds a driver to safely access the System Management Mode
 931           of the CPU on the Dell Inspiron 8000. The System Management Mode
 932           is used to read cpu temperature and cooling fan status and to
 933           control the fans on the I8K portables.
 934
 935           This driver has been tested only on the Inspiron 8000 but it may
 936           also work with other Dell laptops. You can force loading on other
 937           models by passing the parameter `force=1' to the module. Use at
 938           your own risk.
 939
 940           For information on utilities to make use of this driver see the
 941           I8K Linux utilities web site at:
 942           <http://people.debian.org/~dz/i8k/>
 943
 944           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 945           Say N otherwise.
 946
 947 config X86_REBOOTFIXUPS
 948         bool "Enable X86 board specific fixups for reboot"
 949         depends on X86_32
 950         ---help---
 951           This enables chipset and/or board specific fixups to be done
 952           in order to get reboot to work correctly. This is only needed on
 953           some combinations of hardware and BIOS. The symptom, for which
 954           this config is intended, is when reboot ends with a stalled/hung
 955           system.
 956
 957           Currently, the only fixup is for the Geode machines using
 958           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 959
 960           Say Y if you want to enable the fixup. Currently, it's safe to
 961           enable this option even if you don't need it.
 962           Say N otherwise.
 963
 964 config MICROCODE
 965         tristate "/dev/cpu/microcode - microcode support"
 966         select FW_LOADER
 967         ---help---
 968           If you say Y here, you will be able to update the microcode on
 969           certain Intel and AMD processors. The Intel support is for the
 970           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 971           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 972           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 973           You will obviously need the actual microcode binary data itself
 974           which is not shipped with the Linux kernel.
 975
 976           This option selects the general module only, you need to select
 977           at least one vendor specific module as well.
 978
 979           To compile this driver as a module, choose M here: the
 980           module will be called microcode.
 981
 982 config MICROCODE_INTEL
 983         bool "Intel microcode patch loading support"
 984         depends on MICROCODE
 985         default MICROCODE
 986         select FW_LOADER
 987         ---help---
 988           This options enables microcode patch loading support for Intel
 989           processors.
 990
 991           For latest news and information on obtaining all the required
 992           Intel ingredients for this driver, check:
 993           <http://www.urbanmyth.org/microcode/>.
 994
 995 config MICROCODE_AMD
 996         bool "AMD microcode patch loading support"
 997         depends on MICROCODE
 998         select FW_LOADER
 999         ---help---
1000           If you select this option, microcode patch loading support for AMD
1001           processors will be enabled.
1002
1003 config MICROCODE_OLD_INTERFACE
1004         def_bool y
1005         depends on MICROCODE
1006
1007 config X86_MSR
1008         tristate "/dev/cpu/*/msr - Model-specific register support"
1009         ---help---
1010           This device gives privileged processes access to the x86
1011           Model-Specific Registers (MSRs).  It is a character device with
1012           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1013           MSR accesses are directed to a specific CPU on multi-processor
1014           systems.
1015
1016 config X86_CPUID
1017         tristate "/dev/cpu/*/cpuid - CPU information support"
1018         ---help---
1019           This device gives processes access to the x86 CPUID instruction to
1020           be executed on a specific processor.  It is a character device
1021           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1022           /dev/cpu/31/cpuid.
1023
1024 choice
1025         prompt "High Memory Support"
1026         default HIGHMEM4G if !X86_NUMAQ
1027         default HIGHMEM64G if X86_NUMAQ
1028         depends on X86_32
1029
1030 config NOHIGHMEM
1031         bool "off"
1032         depends on !X86_NUMAQ
1033         ---help---
1034           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1035           However, the address space of 32-bit x86 processors is only 4
1036           Gigabytes large. That means that, if you have a large amount of
1037           physical memory, not all of it can be "permanently mapped" by the
1038           kernel. The physical memory that's not permanently mapped is called
1039           "high memory".
1040
1041           If you are compiling a kernel which will never run on a machine with
1042           more than 1 Gigabyte total physical RAM, answer "off" here (default
1043           choice and suitable for most users). This will result in a "3GB/1GB"
1044           split: 3GB are mapped so that each process sees a 3GB virtual memory
1045           space and the remaining part of the 4GB virtual memory space is used
1046           by the kernel to permanently map as much physical memory as
1047           possible.
1048
1049           If the machine has between 1 and 4 Gigabytes physical RAM, then
1050           answer "4GB" here.
1051
1052           If more than 4 Gigabytes is used then answer "64GB" here. This
1053           selection turns Intel PAE (Physical Address Extension) mode on.
1054           PAE implements 3-level paging on IA32 processors. PAE is fully
1055           supported by Linux, PAE mode is implemented on all recent Intel
1056           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1057           then the kernel will not boot on CPUs that don't support PAE!
1058
1059           The actual amount of total physical memory will either be
1060           auto detected or can be forced by using a kernel command line option
1061           such as "mem=256M". (Try "man bootparam" or see the documentation of
1062           your boot loader (lilo or loadlin) about how to pass options to the
1063           kernel at boot time.)
1064
1065           If unsure, say "off".
1066
1067 config HIGHMEM4G
1068         bool "4GB"
1069         depends on !X86_NUMAQ
1070         ---help---
1071           Select this if you have a 32-bit processor and between 1 and 4
1072           gigabytes of physical RAM.
1073
1074 config HIGHMEM64G
1075         bool "64GB"
1076         depends on !M386 && !M486
1077         select X86_PAE
1078         ---help---
1079           Select this if you have a 32-bit processor and more than 4
1080           gigabytes of physical RAM.
1081
1082 endchoice
1083
1084 choice
1085         depends on EXPERIMENTAL
1086         prompt "Memory split" if EMBEDDED
1087         default VMSPLIT_3G
1088         depends on X86_32
1089         ---help---
1090           Select the desired split between kernel and user memory.
1091
1092           If the address range available to the kernel is less than the
1093           physical memory installed, the remaining memory will be available
1094           as "high memory". Accessing high memory is a little more costly
1095           than low memory, as it needs to be mapped into the kernel first.
1096           Note that increasing the kernel address space limits the range
1097           available to user programs, making the address space there
1098           tighter.  Selecting anything other than the default 3G/1G split
1099           will also likely make your kernel incompatible with binary-only
1100           kernel modules.
1101
1102           If you are not absolutely sure what you are doing, leave this
1103           option alone!
1104
1105         config VMSPLIT_3G
1106                 bool "3G/1G user/kernel split"
1107         config VMSPLIT_3G_OPT
1108                 depends on !X86_PAE
1109                 bool "3G/1G user/kernel split (for full 1G low memory)"
1110         config VMSPLIT_2G
1111                 bool "2G/2G user/kernel split"
1112         config VMSPLIT_2G_OPT
1113                 depends on !X86_PAE
1114                 bool "2G/2G user/kernel split (for full 2G low memory)"
1115         config VMSPLIT_1G
1116                 bool "1G/3G user/kernel split"
1117 endchoice
1118
1119 config PAGE_OFFSET
1120         hex
1121         default 0xB0000000 if VMSPLIT_3G_OPT
1122         default 0x80000000 if VMSPLIT_2G
1123         default 0x78000000 if VMSPLIT_2G_OPT
1124         default 0x40000000 if VMSPLIT_1G
1125         default 0xC0000000
1126         depends on X86_32
1127
1128 config HIGHMEM
1129         def_bool y
1130         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1131
1132 config X86_PAE
1133         bool "PAE (Physical Address Extension) Support"
1134         depends on X86_32 && !HIGHMEM4G
1135         ---help---
1136           PAE is required for NX support, and furthermore enables
1137           larger swapspace support for non-overcommit purposes. It
1138           has the cost of more pagetable lookup overhead, and also
1139           consumes more pagetable space per process.
1140
1141 config ARCH_PHYS_ADDR_T_64BIT
1142         def_bool X86_64 || X86_PAE
1143
1144 config DIRECT_GBPAGES
1145         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1146         default y
1147         depends on X86_64
1148         ---help---
1149           Allow the kernel linear mapping to use 1GB pages on CPUs that
1150           support it. This can improve the kernel's performance a tiny bit by
1151           reducing TLB pressure. If in doubt, say "Y".
1152
1153 # Common NUMA Features
1154 config NUMA
1155         bool "Numa Memory Allocation and Scheduler Support"
1156         depends on SMP
1157         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1158         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1159         ---help---
1160           Enable NUMA (Non Uniform Memory Access) support.
1161
1162           The kernel will try to allocate memory used by a CPU on the
1163           local memory controller of the CPU and add some more
1164           NUMA awareness to the kernel.
1165
1166           For 64-bit this is recommended if the system is Intel Core i7
1167           (or later), AMD Opteron, or EM64T NUMA.
1168
1169           For 32-bit this is only needed on (rare) 32-bit-only platforms
1170           that support NUMA topologies, such as NUMAQ / Summit, or if you
1171           boot a 32-bit kernel on a 64-bit NUMA platform.
1172
1173           Otherwise, you should say N.
1174
1175 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1176         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1177
1178 config K8_NUMA
1179         def_bool y
1180         prompt "Old style AMD Opteron NUMA detection"
1181         depends on X86_64 && NUMA && PCI
1182         ---help---
1183           Enable K8 NUMA node topology detection.  You should say Y here if
1184           you have a multi processor AMD K8 system. This uses an old
1185           method to read the NUMA configuration directly from the builtin
1186           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1187           instead, which also takes priority if both are compiled in.
1188
1189 config X86_64_ACPI_NUMA
1190         def_bool y
1191         prompt "ACPI NUMA detection"
1192         depends on X86_64 && NUMA && ACPI && PCI
1193         select ACPI_NUMA
1194         ---help---
1195           Enable ACPI SRAT based node topology detection.
1196
1197 # Some NUMA nodes have memory ranges that span
1198 # other nodes.  Even though a pfn is valid and
1199 # between a node's start and end pfns, it may not
1200 # reside on that node.  See memmap_init_zone()
1201 # for details.
1202 config NODES_SPAN_OTHER_NODES
1203         def_bool y
1204         depends on X86_64_ACPI_NUMA
1205
1206 config NUMA_EMU
1207         bool "NUMA emulation"
1208         depends on X86_64 && NUMA
1209         ---help---
1210           Enable NUMA emulation. A flat machine will be split
1211           into virtual nodes when booted with "numa=fake=N", where N is the
1212           number of nodes. This is only useful for debugging.
1213
1214 config NODES_SHIFT
1215         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1216         range 1 9
1217         default "9" if MAXSMP
1218         default "6" if X86_64
1219         default "4" if X86_NUMAQ
1220         default "3"
1221         depends on NEED_MULTIPLE_NODES
1222         ---help---
1223           Specify the maximum number of NUMA Nodes available on the target
1224           system.  Increases memory reserved to accommodate various tables.
1225
1226 config HAVE_ARCH_BOOTMEM
1227         def_bool y
1228         depends on X86_32 && NUMA
1229
1230 config ARCH_HAVE_MEMORY_PRESENT
1231         def_bool y
1232         depends on X86_32 && DISCONTIGMEM
1233
1234 config NEED_NODE_MEMMAP_SIZE
1235         def_bool y
1236         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1237
1238 config HAVE_ARCH_ALLOC_REMAP
1239         def_bool y
1240         depends on X86_32 && NUMA
1241
1242 config ARCH_FLATMEM_ENABLE
1243         def_bool y
1244         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1245
1246 config ARCH_DISCONTIGMEM_ENABLE
1247         def_bool y
1248         depends on NUMA && X86_32
1249
1250 config ARCH_DISCONTIGMEM_DEFAULT
1251         def_bool y
1252         depends on NUMA && X86_32
1253
1254 config ARCH_PROC_KCORE_TEXT
1255         def_bool y
1256         depends on X86_64 && PROC_KCORE
1257
1258 config ARCH_SPARSEMEM_DEFAULT
1259         def_bool y
1260         depends on X86_64
1261
1262 config ARCH_SPARSEMEM_ENABLE
1263         def_bool y
1264         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1265         select SPARSEMEM_STATIC if X86_32
1266         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1267
1268 config ARCH_SELECT_MEMORY_MODEL
1269         def_bool y
1270         depends on ARCH_SPARSEMEM_ENABLE
1271
1272 config ARCH_MEMORY_PROBE
1273         def_bool X86_64
1274         depends on MEMORY_HOTPLUG
1275
1276 config ILLEGAL_POINTER_VALUE
1277        hex
1278        default 0 if X86_32
1279        default 0xdead000000000000 if X86_64
1280
1281 source "mm/Kconfig"
1282
1283 config HIGHPTE
1284         bool "Allocate 3rd-level pagetables from highmem"
1285         depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1286         ---help---
1287           The VM uses one page table entry for each page of physical memory.
1288           For systems with a lot of RAM, this can be wasteful of precious
1289           low memory.  Setting this option will put user-space page table
1290           entries in high memory.
1291
1292 config X86_CHECK_BIOS_CORRUPTION
1293         bool "Check for low memory corruption"
1294         ---help---
1295           Periodically check for memory corruption in low memory, which
1296           is suspected to be caused by BIOS.  Even when enabled in the
1297           configuration, it is disabled at runtime.  Enable it by
1298           setting "memory_corruption_check=1" on the kernel command
1299           line.  By default it scans the low 64k of memory every 60
1300           seconds; see the memory_corruption_check_size and
1301           memory_corruption_check_period parameters in
1302           Documentation/kernel-parameters.txt to adjust this.
1303
1304           When enabled with the default parameters, this option has
1305           almost no overhead, as it reserves a relatively small amount
1306           of memory and scans it infrequently.  It both detects corruption
1307           and prevents it from affecting the running system.
1308
1309           It is, however, intended as a diagnostic tool; if repeatable
1310           BIOS-originated corruption always affects the same memory,
1311           you can use memmap= to prevent the kernel from using that
1312           memory.
1313
1314 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1315         bool "Set the default setting of memory_corruption_check"
1316         depends on X86_CHECK_BIOS_CORRUPTION
1317         default y
1318         ---help---
1319           Set whether the default state of memory_corruption_check is
1320           on or off.
1321
1322 config X86_RESERVE_LOW_64K
1323         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1324         default y
1325         ---help---
1326           Reserve the first 64K of physical RAM on BIOSes that are known
1327           to potentially corrupt that memory range. A numbers of BIOSes are
1328           known to utilize this area during suspend/resume, so it must not
1329           be used by the kernel.
1330
1331           Set this to N if you are absolutely sure that you trust the BIOS
1332           to get all its memory reservations and usages right.
1333
1334           If you have doubts about the BIOS (e.g. suspend/resume does not
1335           work or there's kernel crashes after certain hardware hotplug
1336           events) and it's not AMI or Phoenix, then you might want to enable
1337           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1338           corruption patterns.
1339
1340           Say Y if unsure.
1341
1342 config MATH_EMULATION
1343         bool
1344         prompt "Math emulation" if X86_32
1345         ---help---
1346           Linux can emulate a math coprocessor (used for floating point
1347           operations) if you don't have one. 486DX and Pentium processors have
1348           a math coprocessor built in, 486SX and 386 do not, unless you added
1349           a 487DX or 387, respectively. (The messages during boot time can
1350           give you some hints here ["man dmesg"].) Everyone needs either a
1351           coprocessor or this emulation.
1352
1353           If you don't have a math coprocessor, you need to say Y here; if you
1354           say Y here even though you have a coprocessor, the coprocessor will
1355           be used nevertheless. (This behavior can be changed with the kernel
1356           command line option "no387", which comes handy if your coprocessor
1357           is broken. Try "man bootparam" or see the documentation of your boot
1358           loader (lilo or loadlin) about how to pass options to the kernel at
1359           boot time.) This means that it is a good idea to say Y here if you
1360           intend to use this kernel on different machines.
1361
1362           More information about the internals of the Linux math coprocessor
1363           emulation can be found in <file:arch/x86/math-emu/README>.
1364
1365           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1366           kernel, it won't hurt.
1367
1368 config MTRR
1369         bool
1370         default y
1371         prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1372         ---help---
1373           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1374           the Memory Type Range Registers (MTRRs) may be used to control
1375           processor access to memory ranges. This is most useful if you have
1376           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1377           allows bus write transfers to be combined into a larger transfer
1378           before bursting over the PCI/AGP bus. This can increase performance
1379           of image write operations 2.5 times or more. Saying Y here creates a
1380           /proc/mtrr file which may be used to manipulate your processor's
1381           MTRRs. Typically the X server should use this.
1382
1383           This code has a reasonably generic interface so that similar
1384           control registers on other processors can be easily supported
1385           as well:
1386
1387           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1388           Registers (ARRs) which provide a similar functionality to MTRRs. For
1389           these, the ARRs are used to emulate the MTRRs.
1390           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1391           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1392           write-combining. All of these processors are supported by this code
1393           and it makes sense to say Y here if you have one of them.
1394
1395           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1396           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1397           can lead to all sorts of problems, so it's good to say Y here.
1398
1399           You can safely say Y even if your machine doesn't have MTRRs, you'll
1400           just add about 9 KB to your kernel.
1401
1402           See <file:Documentation/x86/mtrr.txt> for more information.
1403
1404 config MTRR_SANITIZER
1405         def_bool y
1406         prompt "MTRR cleanup support"
1407         depends on MTRR
1408         ---help---
1409           Convert MTRR layout from continuous to discrete, so X drivers can
1410           add writeback entries.
1411
1412           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1413           The largest mtrr entry size for a continuous block can be set with
1414           mtrr_chunk_size.
1415
1416           If unsure, say Y.
1417
1418 config MTRR_SANITIZER_ENABLE_DEFAULT
1419         int "MTRR cleanup enable value (0-1)"
1420         range 0 1
1421         default "0"
1422         depends on MTRR_SANITIZER
1423         ---help---
1424           Enable mtrr cleanup default value
1425
1426 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1427         int "MTRR cleanup spare reg num (0-7)"
1428         range 0 7
1429         default "1"
1430         depends on MTRR_SANITIZER
1431         ---help---
1432           mtrr cleanup spare entries default, it can be changed via
1433           mtrr_spare_reg_nr=N on the kernel command line.
1434
1435 config X86_PAT
1436         bool
1437         default y
1438         prompt "x86 PAT support" if EMBEDDED
1439         depends on MTRR
1440         ---help---
1441           Use PAT attributes to setup page level cache control.
1442
1443           PATs are the modern equivalents of MTRRs and are much more
1444           flexible than MTRRs.
1445
1446           Say N here if you see bootup problems (boot crash, boot hang,
1447           spontaneous reboots) or a non-working video driver.
1448
1449           If unsure, say Y.
1450
1451 config ARCH_USES_PG_UNCACHED
1452         def_bool y
1453         depends on X86_PAT
1454
1455 config EFI
1456         bool "EFI runtime service support"
1457         depends on ACPI
1458         ---help---
1459           This enables the kernel to use EFI runtime services that are
1460           available (such as the EFI variable services).
1461
1462           This option is only useful on systems that have EFI firmware.
1463           In addition, you should use the latest ELILO loader available
1464           at <http://elilo.sourceforge.net> in order to take advantage
1465           of EFI runtime services. However, even with this option, the
1466           resultant kernel should continue to boot on existing non-EFI
1467           platforms.
1468
1469 config SECCOMP
1470         def_bool y
1471         prompt "Enable seccomp to safely compute untrusted bytecode"
1472         ---help---
1473           This kernel feature is useful for number crunching applications
1474           that may need to compute untrusted bytecode during their
1475           execution. By using pipes or other transports made available to
1476           the process as file descriptors supporting the read/write
1477           syscalls, it's possible to isolate those applications in
1478           their own address space using seccomp. Once seccomp is
1479           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1480           and the task is only allowed to execute a few safe syscalls
1481           defined by each seccomp mode.
1482
1483           If unsure, say Y. Only embedded should say N here.
1484
1485 config CC_STACKPROTECTOR
1486         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1487         ---help---
1488           This option turns on the -fstack-protector GCC feature. This
1489           feature puts, at the beginning of functions, a canary value on
1490           the stack just before the return address, and validates
1491           the value just before actually returning.  Stack based buffer
1492           overflows (that need to overwrite this return address) now also
1493           overwrite the canary, which gets detected and the attack is then
1494           neutralized via a kernel panic.
1495
1496           This feature requires gcc version 4.2 or above, or a distribution
1497           gcc with the feature backported. Older versions are automatically
1498           detected and for those versions, this configuration option is
1499           ignored. (and a warning is printed during bootup)
1500
1501 source kernel/Kconfig.hz
1502
1503 config KEXEC
1504         bool "kexec system call"
1505         ---help---
1506           kexec is a system call that implements the ability to shutdown your
1507           current kernel, and to start another kernel.  It is like a reboot
1508           but it is independent of the system firmware.   And like a reboot
1509           you can start any kernel with it, not just Linux.
1510
1511           The name comes from the similarity to the exec system call.
1512
1513           It is an ongoing process to be certain the hardware in a machine
1514           is properly shutdown, so do not be surprised if this code does not
1515           initially work for you.  It may help to enable device hotplugging
1516           support.  As of this writing the exact hardware interface is
1517           strongly in flux, so no good recommendation can be made.
1518
1519 config CRASH_DUMP
1520         bool "kernel crash dumps"
1521         depends on X86_64 || (X86_32 && HIGHMEM)
1522         ---help---
1523           Generate crash dump after being started by kexec.
1524           This should be normally only set in special crash dump kernels
1525           which are loaded in the main kernel with kexec-tools into
1526           a specially reserved region and then later executed after
1527           a crash by kdump/kexec. The crash dump kernel must be compiled
1528           to a memory address not used by the main kernel or BIOS using
1529           PHYSICAL_START, or it must be built as a relocatable image
1530           (CONFIG_RELOCATABLE=y).
1531           For more details see Documentation/kdump/kdump.txt
1532
1533 config KEXEC_JUMP
1534         bool "kexec jump (EXPERIMENTAL)"
1535         depends on EXPERIMENTAL
1536         depends on KEXEC && HIBERNATION
1537         ---help---
1538           Jump between original kernel and kexeced kernel and invoke
1539           code in physical address mode via KEXEC
1540
1541 config PHYSICAL_START
1542         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1543         default "0x1000000"
1544         ---help---
1545           This gives the physical address where the kernel is loaded.
1546
1547           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1548           bzImage will decompress itself to above physical address and
1549           run from there. Otherwise, bzImage will run from the address where
1550           it has been loaded by the boot loader and will ignore above physical
1551           address.
1552
1553           In normal kdump cases one does not have to set/change this option
1554           as now bzImage can be compiled as a completely relocatable image
1555           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1556           address. This option is mainly useful for the folks who don't want
1557           to use a bzImage for capturing the crash dump and want to use a
1558           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1559           to be specifically compiled to run from a specific memory area
1560           (normally a reserved region) and this option comes handy.
1561
1562           So if you are using bzImage for capturing the crash dump,
1563           leave the value here unchanged to 0x1000000 and set
1564           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1565           for capturing the crash dump change this value to start of
1566           the reserved region.  In other words, it can be set based on
1567           the "X" value as specified in the "crashkernel=YM@XM"
1568           command line boot parameter passed to the panic-ed
1569           kernel. Please take a look at Documentation/kdump/kdump.txt
1570           for more details about crash dumps.
1571
1572           Usage of bzImage for capturing the crash dump is recommended as
1573           one does not have to build two kernels. Same kernel can be used
1574           as production kernel and capture kernel. Above option should have
1575           gone away after relocatable bzImage support is introduced. But it
1576           is present because there are users out there who continue to use
1577           vmlinux for dump capture. This option should go away down the
1578           line.
1579
1580           Don't change this unless you know what you are doing.
1581
1582 config RELOCATABLE
1583         bool "Build a relocatable kernel"
1584         default y
1585         ---help---
1586           This builds a kernel image that retains relocation information
1587           so it can be loaded someplace besides the default 1MB.
1588           The relocations tend to make the kernel binary about 10% larger,
1589           but are discarded at runtime.
1590
1591           One use is for the kexec on panic case where the recovery kernel
1592           must live at a different physical address than the primary
1593           kernel.
1594
1595           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1596           it has been loaded at and the compile time physical address
1597           (CONFIG_PHYSICAL_START) is ignored.
1598
1599 # Relocation on x86-32 needs some additional build support
1600 config X86_NEED_RELOCS
1601         def_bool y
1602         depends on X86_32 && RELOCATABLE
1603
1604 config PHYSICAL_ALIGN
1605         hex
1606         prompt "Alignment value to which kernel should be aligned" if X86_32
1607         default "0x1000000"
1608         range 0x2000 0x1000000
1609         ---help---
1610           This value puts the alignment restrictions on physical address
1611           where kernel is loaded and run from. Kernel is compiled for an
1612           address which meets above alignment restriction.
1613
1614           If bootloader loads the kernel at a non-aligned address and
1615           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1616           address aligned to above value and run from there.
1617
1618           If bootloader loads the kernel at a non-aligned address and
1619           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1620           load address and decompress itself to the address it has been
1621           compiled for and run from there. The address for which kernel is
1622           compiled already meets above alignment restrictions. Hence the
1623           end result is that kernel runs from a physical address meeting
1624           above alignment restrictions.
1625
1626           Don't change this unless you know what you are doing.
1627
1628 config HOTPLUG_CPU
1629         bool "Support for hot-pluggable CPUs"
1630         depends on SMP && HOTPLUG
1631         ---help---
1632           Say Y here to allow turning CPUs off and on. CPUs can be
1633           controlled through /sys/devices/system/cpu.
1634           ( Note: power management support will enable this option
1635             automatically on SMP systems. )
1636           Say N if you want to disable CPU hotplug.
1637
1638 config COMPAT_VDSO
1639         def_bool y
1640         prompt "Compat VDSO support"
1641         depends on X86_32 || IA32_EMULATION
1642         ---help---
1643           Map the 32-bit VDSO to the predictable old-style address too.
1644
1645           Say N here if you are running a sufficiently recent glibc
1646           version (2.3.3 or later), to remove the high-mapped
1647           VDSO mapping and to exclusively use the randomized VDSO.
1648
1649           If unsure, say Y.
1650
1651 config CMDLINE_BOOL
1652         bool "Built-in kernel command line"
1653         default n
1654         ---help---
1655           Allow for specifying boot arguments to the kernel at
1656           build time.  On some systems (e.g. embedded ones), it is
1657           necessary or convenient to provide some or all of the
1658           kernel boot arguments with the kernel itself (that is,
1659           to not rely on the boot loader to provide them.)
1660
1661           To compile command line arguments into the kernel,
1662           set this option to 'Y', then fill in the
1663           the boot arguments in CONFIG_CMDLINE.
1664
1665           Systems with fully functional boot loaders (i.e. non-embedded)
1666           should leave this option set to 'N'.
1667
1668 config CMDLINE
1669         string "Built-in kernel command string"
1670         depends on CMDLINE_BOOL
1671         default ""
1672         ---help---
1673           Enter arguments here that should be compiled into the kernel
1674           image and used at boot time.  If the boot loader provides a
1675           command line at boot time, it is appended to this string to
1676           form the full kernel command line, when the system boots.
1677
1678           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1679           change this behavior.
1680
1681           In most cases, the command line (whether built-in or provided
1682           by the boot loader) should specify the device for the root
1683           file system.
1684
1685 config CMDLINE_OVERRIDE
1686         bool "Built-in command line overrides boot loader arguments"
1687         default n
1688         depends on CMDLINE_BOOL
1689         ---help---
1690           Set this option to 'Y' to have the kernel ignore the boot loader
1691           command line, and use ONLY the built-in command line.
1692
1693           This is used to work around broken boot loaders.  This should
1694           be set to 'N' under normal conditions.
1695
1696 endmenu
1697
1698 config ARCH_ENABLE_MEMORY_HOTPLUG
1699         def_bool y
1700         depends on X86_64 || (X86_32 && HIGHMEM)
1701
1702 config ARCH_ENABLE_MEMORY_HOTREMOVE
1703         def_bool y
1704         depends on MEMORY_HOTPLUG
1705
1706 config HAVE_ARCH_EARLY_PFN_TO_NID
1707         def_bool X86_64
1708         depends on NUMA
1709
1710 menu "Power management and ACPI options"
1711
1712 config ARCH_HIBERNATION_HEADER
1713         def_bool y
1714         depends on X86_64 && HIBERNATION
1715
1716 source "kernel/power/Kconfig"
1717
1718 source "drivers/acpi/Kconfig"
1719
1720 source "drivers/sfi/Kconfig"
1721
1722 config X86_APM_BOOT
1723         bool
1724         default y
1725         depends on APM || APM_MODULE
1726
1727 menuconfig APM
1728         tristate "APM (Advanced Power Management) BIOS support"
1729         depends on X86_32 && PM_SLEEP
1730         ---help---
1731           APM is a BIOS specification for saving power using several different
1732           techniques. This is mostly useful for battery powered laptops with
1733           APM compliant BIOSes. If you say Y here, the system time will be
1734           reset after a RESUME operation, the /proc/apm device will provide
1735           battery status information, and user-space programs will receive
1736           notification of APM "events" (e.g. battery status change).
1737
1738           If you select "Y" here, you can disable actual use of the APM
1739           BIOS by passing the "apm=off" option to the kernel at boot time.
1740
1741           Note that the APM support is almost completely disabled for
1742           machines with more than one CPU.
1743
1744           In order to use APM, you will need supporting software. For location
1745           and more information, read <file:Documentation/power/pm.txt> and the
1746           Battery Powered Linux mini-HOWTO, available from
1747           <http://www.tldp.org/docs.html#howto>.
1748
1749           This driver does not spin down disk drives (see the hdparm(8)
1750           manpage ("man 8 hdparm") for that), and it doesn't turn off
1751           VESA-compliant "green" monitors.
1752
1753           This driver does not support the TI 4000M TravelMate and the ACER
1754           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1755           desktop machines also don't have compliant BIOSes, and this driver
1756           may cause those machines to panic during the boot phase.
1757
1758           Generally, if you don't have a battery in your machine, there isn't
1759           much point in using this driver and you should say N. If you get
1760           random kernel OOPSes or reboots that don't seem to be related to
1761           anything, try disabling/enabling this option (or disabling/enabling
1762           APM in your BIOS).
1763
1764           Some other things you should try when experiencing seemingly random,
1765           "weird" problems:
1766
1767           1) make sure that you have enough swap space and that it is
1768           enabled.
1769           2) pass the "no-hlt" option to the kernel
1770           3) switch on floating point emulation in the kernel and pass
1771           the "no387" option to the kernel
1772           4) pass the "floppy=nodma" option to the kernel
1773           5) pass the "mem=4M" option to the kernel (thereby disabling
1774           all but the first 4 MB of RAM)
1775           6) make sure that the CPU is not over clocked.
1776           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1777           8) disable the cache from your BIOS settings
1778           9) install a fan for the video card or exchange video RAM
1779           10) install a better fan for the CPU
1780           11) exchange RAM chips
1781           12) exchange the motherboard.
1782
1783           To compile this driver as a module, choose M here: the
1784           module will be called apm.
1785
1786 if APM
1787
1788 config APM_IGNORE_USER_SUSPEND
1789         bool "Ignore USER SUSPEND"
1790         ---help---
1791           This option will ignore USER SUSPEND requests. On machines with a
1792           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1793           series notebooks, it is necessary to say Y because of a BIOS bug.
1794
1795 config APM_DO_ENABLE
1796         bool "Enable PM at boot time"
1797         ---help---
1798           Enable APM features at boot time. From page 36 of the APM BIOS
1799           specification: "When disabled, the APM BIOS does not automatically
1800           power manage devices, enter the Standby State, enter the Suspend
1801           State, or take power saving steps in response to CPU Idle calls."
1802           This driver will make CPU Idle calls when Linux is idle (unless this
1803           feature is turned off -- see "Do CPU IDLE calls", below). This
1804           should always save battery power, but more complicated APM features
1805           will be dependent on your BIOS implementation. You may need to turn
1806           this option off if your computer hangs at boot time when using APM
1807           support, or if it beeps continuously instead of suspending. Turn
1808           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1809           T400CDT. This is off by default since most machines do fine without
1810           this feature.
1811
1812 config APM_CPU_IDLE
1813         bool "Make CPU Idle calls when idle"
1814         ---help---
1815           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1816           On some machines, this can activate improved power savings, such as
1817           a slowed CPU clock rate, when the machine is idle. These idle calls
1818           are made after the idle loop has run for some length of time (e.g.,
1819           333 mS). On some machines, this will cause a hang at boot time or
1820           whenever the CPU becomes idle. (On machines with more than one CPU,
1821           this option does nothing.)
1822
1823 config APM_DISPLAY_BLANK
1824         bool "Enable console blanking using APM"
1825         ---help---
1826           Enable console blanking using the APM. Some laptops can use this to
1827           turn off the LCD backlight when the screen blanker of the Linux
1828           virtual console blanks the screen. Note that this is only used by
1829           the virtual console screen blanker, and won't turn off the backlight
1830           when using the X Window system. This also doesn't have anything to
1831           do with your VESA-compliant power-saving monitor. Further, this
1832           option doesn't work for all laptops -- it might not turn off your
1833           backlight at all, or it might print a lot of errors to the console,
1834           especially if you are using gpm.
1835
1836 config APM_ALLOW_INTS
1837         bool "Allow interrupts during APM BIOS calls"
1838         ---help---
1839           Normally we disable external interrupts while we are making calls to
1840           the APM BIOS as a measure to lessen the effects of a badly behaving
1841           BIOS implementation.  The BIOS should reenable interrupts if it
1842           needs to.  Unfortunately, some BIOSes do not -- especially those in
1843           many of the newer IBM Thinkpads.  If you experience hangs when you
1844           suspend, try setting this to Y.  Otherwise, say N.
1845
1846 endif # APM
1847
1848 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1849
1850 source "drivers/cpuidle/Kconfig"
1851
1852 source "drivers/idle/Kconfig"
1853
1854 endmenu
1855
1856
1857 menu "Bus options (PCI etc.)"
1858
1859 config PCI
1860         bool "PCI support"
1861         default y
1862         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1863         ---help---
1864           Find out whether you have a PCI motherboard. PCI is the name of a
1865           bus system, i.e. the way the CPU talks to the other stuff inside
1866           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1867           VESA. If you have PCI, say Y, otherwise N.
1868
1869 choice
1870         prompt "PCI access mode"
1871         depends on X86_32 && PCI
1872         default PCI_GOANY
1873         ---help---
1874           On PCI systems, the BIOS can be used to detect the PCI devices and
1875           determine their configuration. However, some old PCI motherboards
1876           have BIOS bugs and may crash if this is done. Also, some embedded
1877           PCI-based systems don't have any BIOS at all. Linux can also try to
1878           detect the PCI hardware directly without using the BIOS.
1879
1880           With this option, you can specify how Linux should detect the
1881           PCI devices. If you choose "BIOS", the BIOS will be used,
1882           if you choose "Direct", the BIOS won't be used, and if you
1883           choose "MMConfig", then PCI Express MMCONFIG will be used.
1884           If you choose "Any", the kernel will try MMCONFIG, then the
1885           direct access method and falls back to the BIOS if that doesn't
1886           work. If unsure, go with the default, which is "Any".
1887
1888 config PCI_GOBIOS
1889         bool "BIOS"
1890
1891 config PCI_GOMMCONFIG
1892         bool "MMConfig"
1893
1894 config PCI_GODIRECT
1895         bool "Direct"
1896
1897 config PCI_GOOLPC
1898         bool "OLPC"
1899         depends on OLPC
1900
1901 config PCI_GOANY
1902         bool "Any"
1903
1904 endchoice
1905
1906 config PCI_BIOS
1907         def_bool y
1908         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1909
1910 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1911 config PCI_DIRECT
1912         def_bool y
1913         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1914
1915 config PCI_MMCONFIG
1916         def_bool y
1917         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1918
1919 config PCI_OLPC
1920         def_bool y
1921         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1922
1923 config PCI_DOMAINS
1924         def_bool y
1925         depends on PCI
1926
1927 config PCI_MMCONFIG
1928         bool "Support mmconfig PCI config space access"
1929         depends on X86_64 && PCI && ACPI
1930
1931 config DMAR
1932         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1933         depends on PCI_MSI && ACPI && EXPERIMENTAL
1934         help
1935           DMA remapping (DMAR) devices support enables independent address
1936           translations for Direct Memory Access (DMA) from devices.
1937           These DMA remapping devices are reported via ACPI tables
1938           and include PCI device scope covered by these DMA
1939           remapping devices.
1940
1941 config DMAR_DEFAULT_ON
1942         def_bool y
1943         prompt "Enable DMA Remapping Devices by default"
1944         depends on DMAR
1945         help
1946           Selecting this option will enable a DMAR device at boot time if
1947           one is found. If this option is not selected, DMAR support can
1948           be enabled by passing intel_iommu=on to the kernel. It is
1949           recommended you say N here while the DMAR code remains
1950           experimental.
1951
1952 config DMAR_BROKEN_GFX_WA
1953         def_bool n
1954         prompt "Workaround broken graphics drivers (going away soon)"
1955         depends on DMAR && BROKEN
1956         ---help---
1957           Current Graphics drivers tend to use physical address
1958           for DMA and avoid using DMA APIs. Setting this config
1959           option permits the IOMMU driver to set a unity map for
1960           all the OS-visible memory. Hence the driver can continue
1961           to use physical addresses for DMA, at least until this
1962           option is removed in the 2.6.32 kernel.
1963
1964 config DMAR_FLOPPY_WA
1965         def_bool y
1966         depends on DMAR
1967         ---help---
1968           Floppy disk drivers are known to bypass DMA API calls
1969           thereby failing to work when IOMMU is enabled. This
1970           workaround will setup a 1:1 mapping for the first
1971           16MiB to make floppy (an ISA device) work.
1972
1973 config INTR_REMAP
1974         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1975         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1976         ---help---
1977           Supports Interrupt remapping for IO-APIC and MSI devices.
1978           To use x2apic mode in the CPU's which support x2APIC enhancements or
1979           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1980
1981 source "drivers/pci/pcie/Kconfig"
1982
1983 source "drivers/pci/Kconfig"
1984
1985 # x86_64 have no ISA slots, but do have ISA-style DMA.
1986 config ISA_DMA_API
1987         def_bool y
1988
1989 if X86_32
1990
1991 config ISA
1992         bool "ISA support"
1993         ---help---
1994           Find out whether you have ISA slots on your motherboard.  ISA is the
1995           name of a bus system, i.e. the way the CPU talks to the other stuff
1996           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1997           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1998           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1999
2000 config EISA
2001         bool "EISA support"
2002         depends on ISA
2003         ---help---
2004           The Extended Industry Standard Architecture (EISA) bus was
2005           developed as an open alternative to the IBM MicroChannel bus.
2006
2007           The EISA bus provided some of the features of the IBM MicroChannel
2008           bus while maintaining backward compatibility with cards made for
2009           the older ISA bus.  The EISA bus saw limited use between 1988 and
2010           1995 when it was made obsolete by the PCI bus.
2011
2012           Say Y here if you are building a kernel for an EISA-based machine.
2013
2014           Otherwise, say N.
2015
2016 source "drivers/eisa/Kconfig"
2017
2018 config MCA
2019         bool "MCA support"
2020         ---help---
2021           MicroChannel Architecture is found in some IBM PS/2 machines and
2022           laptops.  It is a bus system similar to PCI or ISA. See
2023           <file:Documentation/mca.txt> (and especially the web page given
2024           there) before attempting to build an MCA bus kernel.
2025
2026 source "drivers/mca/Kconfig"
2027
2028 config SCx200
2029         tristate "NatSemi SCx200 support"
2030         ---help---
2031           This provides basic support for National Semiconductor's
2032           (now AMD's) Geode processors.  The driver probes for the
2033           PCI-IDs of several on-chip devices, so its a good dependency
2034           for other scx200_* drivers.
2035
2036           If compiled as a module, the driver is named scx200.
2037
2038 config SCx200HR_TIMER
2039         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2040         depends on SCx200 && GENERIC_TIME
2041         default y
2042         ---help---
2043           This driver provides a clocksource built upon the on-chip
2044           27MHz high-resolution timer.  Its also a workaround for
2045           NSC Geode SC-1100's buggy TSC, which loses time when the
2046           processor goes idle (as is done by the scheduler).  The
2047           other workaround is idle=poll boot option.
2048
2049 config OLPC
2050         bool "One Laptop Per Child support"
2051         select GPIOLIB
2052         default n
2053         ---help---
2054           Add support for detecting the unique features of the OLPC
2055           XO hardware.
2056
2057 endif # X86_32
2058
2059 config K8_NB
2060         def_bool y
2061         depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2062
2063 source "drivers/pcmcia/Kconfig"
2064
2065 source "drivers/pci/hotplug/Kconfig"
2066
2067 endmenu
2068
2069
2070 menu "Executable file formats / Emulations"
2071
2072 source "fs/Kconfig.binfmt"
2073
2074 config IA32_EMULATION
2075         bool "IA32 Emulation"
2076         depends on X86_64
2077         select COMPAT_BINFMT_ELF
2078         ---help---
2079           Include code to run 32-bit programs under a 64-bit kernel. You should
2080           likely turn this on, unless you're 100% sure that you don't have any
2081           32-bit programs left.
2082
2083 config IA32_AOUT
2084         tristate "IA32 a.out support"
2085         depends on IA32_EMULATION
2086         ---help---
2087           Support old a.out binaries in the 32bit emulation.
2088
2089 config COMPAT
2090         def_bool y
2091         depends on IA32_EMULATION
2092
2093 config COMPAT_FOR_U64_ALIGNMENT
2094         def_bool COMPAT
2095         depends on X86_64
2096
2097 config SYSVIPC_COMPAT
2098         def_bool y
2099         depends on COMPAT && SYSVIPC
2100
2101 endmenu
2102
2103
2104 config HAVE_ATOMIC_IOMAP
2105         def_bool y
2106         depends on X86_32
2107
2108 source "net/Kconfig"
2109
2110 source "drivers/Kconfig"
2111
2112 source "drivers/firmware/Kconfig"
2113
2114 source "fs/Kconfig"
2115
2116 source "arch/x86/Kconfig.debug"
2117
2118 source "security/Kconfig"
2119
2120 source "crypto/Kconfig"
2121
2122 source "arch/x86/kvm/Kconfig"
2123
2124 source "lib/Kconfig"