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 NEED_DMA_MAP_STATE
 106        def_bool (X86_64 || DMAR || DMA_API_DEBUG)
 107
 108 config GENERIC_ISA_DMA
 109         def_bool y
 110
 111 config GENERIC_IOMAP
 112         def_bool y
 113
 114 config GENERIC_BUG
 115         def_bool y
 116         depends on BUG
 117         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 118
 119 config GENERIC_BUG_RELATIVE_POINTERS
 120         bool
 121
 122 config GENERIC_HWEIGHT
 123         def_bool y
 124
 125 config GENERIC_GPIO
 126         bool
 127
 128 config ARCH_MAY_HAVE_PC_FDC
 129         def_bool y
 130
 131 config RWSEM_GENERIC_SPINLOCK
 132         def_bool !X86_XADD
 133
 134 config RWSEM_XCHGADD_ALGORITHM
 135         def_bool X86_XADD
 136
 137 config ARCH_HAS_CPU_IDLE_WAIT
 138         def_bool y
 139
 140 config GENERIC_CALIBRATE_DELAY
 141         def_bool y
 142
 143 config GENERIC_TIME_VSYSCALL
 144         bool
 145         default X86_64
 146
 147 config ARCH_HAS_CPU_RELAX
 148         def_bool y
 149
 150 config ARCH_HAS_DEFAULT_IDLE
 151         def_bool y
 152
 153 config ARCH_HAS_CACHE_LINE_SIZE
 154         def_bool y
 155
 156 config HAVE_SETUP_PER_CPU_AREA
 157         def_bool y
 158
 159 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 160         def_bool y
 161
 162 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 163         def_bool y
 164
 165 config HAVE_CPUMASK_OF_CPU_MAP
 166         def_bool X86_64_SMP
 167
 168 config ARCH_HIBERNATION_POSSIBLE
 169         def_bool y
 170
 171 config ARCH_SUSPEND_POSSIBLE
 172         def_bool y
 173
 174 config ZONE_DMA32
 175         bool
 176         default X86_64
 177
 178 config ARCH_POPULATES_NODE_MAP
 179         def_bool y
 180
 181 config AUDIT_ARCH
 182         bool
 183         default X86_64
 184
 185 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 186         def_bool y
 187
 188 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 189         def_bool y
 190
 191 config HAVE_EARLY_RES
 192         def_bool y
 193
 194 config HAVE_INTEL_TXT
 195         def_bool y
 196         depends on EXPERIMENTAL && DMAR && ACPI
 197
 198 # Use the generic interrupt handling code in kernel/irq/:
 199 config GENERIC_HARDIRQS
 200         bool
 201         default y
 202
 203 config GENERIC_HARDIRQS_NO__DO_IRQ
 204        def_bool y
 205
 206 config GENERIC_IRQ_PROBE
 207         bool
 208         default y
 209
 210 config GENERIC_PENDING_IRQ
 211         bool
 212         depends on GENERIC_HARDIRQS && SMP
 213         default y
 214
 215 config USE_GENERIC_SMP_HELPERS
 216         def_bool y
 217         depends on SMP
 218
 219 config X86_32_SMP
 220         def_bool y
 221         depends on X86_32 && SMP
 222
 223 config X86_64_SMP
 224         def_bool y
 225         depends on X86_64 && SMP
 226
 227 config X86_HT
 228         bool
 229         depends on SMP
 230         default y
 231
 232 config X86_TRAMPOLINE
 233         bool
 234         depends on SMP || (64BIT && ACPI_SLEEP)
 235         default y
 236
 237 config X86_32_LAZY_GS
 238         def_bool y
 239         depends on X86_32 && !CC_STACKPROTECTOR
 240
 241 config KTIME_SCALAR
 242         def_bool X86_32
 243 source "init/Kconfig"
 244 source "kernel/Kconfig.freezer"
 245
 246 menu "Processor type and features"
 247
 248 source "kernel/time/Kconfig"
 249
 250 config SMP
 251         bool "Symmetric multi-processing support"
 252         ---help---
 253           This enables support for systems with more than one CPU. If you have
 254           a system with only one CPU, like most personal computers, say N. If
 255           you have a system with more than one CPU, say Y.
 256
 257           If you say N here, the kernel will run on single and multiprocessor
 258           machines, but will use only one CPU of a multiprocessor machine. If
 259           you say Y here, the kernel will run on many, but not all,
 260           singleprocessor machines. On a singleprocessor machine, the kernel
 261           will run faster if you say N here.
 262
 263           Note that if you say Y here and choose architecture "586" or
 264           "Pentium" under "Processor family", the kernel will not work on 486
 265           architectures. Similarly, multiprocessor kernels for the "PPro"
 266           architecture may not work on all Pentium based boards.
 267
 268           People using multiprocessor machines who say Y here should also say
 269           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 270           Management" code will be disabled if you say Y here.
 271
 272           See also <file:Documentation/i386/IO-APIC.txt>,
 273           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 274           <http://www.tldp.org/docs.html#howto>.
 275
 276           If you don't know what to do here, say N.
 277
 278 config X86_X2APIC
 279         bool "Support x2apic"
 280         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 281         ---help---
 282           This enables x2apic support on CPUs that have this feature.
 283
 284           This allows 32-bit apic IDs (so it can support very large systems),
 285           and accesses the local apic via MSRs not via mmio.
 286
 287           If you don't know what to do here, say N.
 288
 289 config SPARSE_IRQ
 290         bool "Support sparse irq numbering"
 291         depends on PCI_MSI || HT_IRQ
 292         ---help---
 293           This enables support for sparse irqs. This is useful for distro
 294           kernels that want to define a high CONFIG_NR_CPUS value but still
 295           want to have low kernel memory footprint on smaller machines.
 296
 297           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 298             out the irq_desc[] array in a more NUMA-friendly way. )
 299
 300           If you don't know what to do here, say N.
 301
 302 config NUMA_IRQ_DESC
 303         def_bool y
 304         depends on SPARSE_IRQ && NUMA
 305
 306 config X86_MPPARSE
 307         bool "Enable MPS table" if ACPI
 308         default y
 309         depends on X86_LOCAL_APIC
 310         ---help---
 311           For old smp systems that do not have proper acpi support. Newer systems
 312           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 313
 314 config X86_BIGSMP
 315         bool "Support for big SMP systems with more than 8 CPUs"
 316         depends on X86_32 && SMP
 317         ---help---
 318           This option is needed for the systems that have more than 8 CPUs
 319
 320 if X86_32
 321 config X86_EXTENDED_PLATFORM
 322         bool "Support for extended (non-PC) x86 platforms"
 323         default y
 324         ---help---
 325           If you disable this option then the kernel will only support
 326           standard PC platforms. (which covers the vast majority of
 327           systems out there.)
 328
 329           If you enable this option then you'll be able to select support
 330           for the following (non-PC) 32 bit x86 platforms:
 331                 AMD Elan
 332                 NUMAQ (IBM/Sequent)
 333                 RDC R-321x SoC
 334                 SGI 320/540 (Visual Workstation)
 335                 Summit/EXA (IBM x440)
 336                 Unisys ES7000 IA32 series
 337                 Moorestown MID devices
 338
 339           If you have one of these systems, or if you want to build a
 340           generic distribution kernel, say Y here - otherwise say N.
 341 endif
 342
 343 if X86_64
 344 config X86_EXTENDED_PLATFORM
 345         bool "Support for extended (non-PC) x86 platforms"
 346         default y
 347         ---help---
 348           If you disable this option then the kernel will only support
 349           standard PC platforms. (which covers the vast majority of
 350           systems out there.)
 351
 352           If you enable this option then you'll be able to select support
 353           for the following (non-PC) 64 bit x86 platforms:
 354                 ScaleMP vSMP
 355                 SGI Ultraviolet
 356
 357           If you have one of these systems, or if you want to build a
 358           generic distribution kernel, say Y here - otherwise say N.
 359 endif
 360 # This is an alphabetically sorted list of 64 bit extended platforms
 361 # Please maintain the alphabetic order if and when there are additions
 362
 363 config X86_VSMP
 364         bool "ScaleMP vSMP"
 365         select PARAVIRT
 366         depends on X86_64 && PCI
 367         depends on X86_EXTENDED_PLATFORM
 368         ---help---
 369           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 370           supposed to run on these EM64T-based machines.  Only choose this option
 371           if you have one of these machines.
 372
 373 config X86_UV
 374         bool "SGI Ultraviolet"
 375         depends on X86_64
 376         depends on X86_EXTENDED_PLATFORM
 377         depends on NUMA
 378         depends on X86_X2APIC
 379         ---help---
 380           This option is needed in order to support SGI Ultraviolet systems.
 381           If you don't have one of these, you should say N here.
 382
 383 # Following is an alphabetically sorted list of 32 bit extended platforms
 384 # Please maintain the alphabetic order if and when there are additions
 385
 386 config X86_ELAN
 387         bool "AMD Elan"
 388         depends on X86_32
 389         depends on X86_EXTENDED_PLATFORM
 390         ---help---
 391           Select this for an AMD Elan processor.
 392
 393           Do not use this option for K6/Athlon/Opteron processors!
 394
 395           If unsure, choose "PC-compatible" instead.
 396
 397 config X86_MRST
 398        bool "Moorestown MID platform"
 399         depends on PCI
 400         depends on PCI_GOANY
 401         depends on X86_32
 402         depends on X86_EXTENDED_PLATFORM
 403         depends on X86_IO_APIC
 404         select APB_TIMER
 405         ---help---
 406           Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 407           Internet Device(MID) platform. Moorestown consists of two chips:
 408           Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
 409           Unlike standard x86 PCs, Moorestown does not have many legacy devices
 410           nor standard legacy replacement devices/features. e.g. Moorestown does
 411           not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
 412
 413 config X86_RDC321X
 414         bool "RDC R-321x SoC"
 415         depends on X86_32
 416         depends on X86_EXTENDED_PLATFORM
 417         select M486
 418         select X86_REBOOTFIXUPS
 419         ---help---
 420           This option is needed for RDC R-321x system-on-chip, also known
 421           as R-8610-(G).
 422           If you don't have one of these chips, you should say N here.
 423
 424 config X86_32_NON_STANDARD
 425         bool "Support non-standard 32-bit SMP architectures"
 426         depends on X86_32 && SMP
 427         depends on X86_EXTENDED_PLATFORM
 428         ---help---
 429           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 430           subarchitectures.  It is intended for a generic binary kernel.
 431           if you select them all, kernel will probe it one by one. and will
 432           fallback to default.
 433
 434 # Alphabetically sorted list of Non standard 32 bit platforms
 435
 436 config X86_NUMAQ
 437         bool "NUMAQ (IBM/Sequent)"
 438         depends on X86_32_NON_STANDARD
 439         depends on PCI
 440         select NUMA
 441         select X86_MPPARSE
 442         ---help---
 443           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 444           NUMA multiquad box. This changes the way that processors are
 445           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 446           of Flat Logical.  You will need a new lynxer.elf file to flash your
 447           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 448
 449 config X86_SUPPORTS_MEMORY_FAILURE
 450         bool
 451         # MCE code calls memory_failure():
 452         depends on X86_MCE
 453         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
 454         depends on !X86_NUMAQ
 455         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
 456         depends on X86_64 || !SPARSEMEM
 457         select ARCH_SUPPORTS_MEMORY_FAILURE
 458         default y
 459
 460 config X86_VISWS
 461         bool "SGI 320/540 (Visual Workstation)"
 462         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 463         depends on X86_32_NON_STANDARD
 464         ---help---
 465           The SGI Visual Workstation series is an IA32-based workstation
 466           based on SGI systems chips with some legacy PC hardware attached.
 467
 468           Say Y here to create a kernel to run on the SGI 320 or 540.
 469
 470           A kernel compiled for the Visual Workstation will run on general
 471           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 472
 473 config X86_SUMMIT
 474         bool "Summit/EXA (IBM x440)"
 475         depends on X86_32_NON_STANDARD
 476         ---help---
 477           This option is needed for IBM systems that use the Summit/EXA chipset.
 478           In particular, it is needed for the x440.
 479
 480 config X86_ES7000
 481         bool "Unisys ES7000 IA32 series"
 482         depends on X86_32_NON_STANDARD && X86_BIGSMP
 483         ---help---
 484           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 485           supposed to run on an IA32-based Unisys ES7000 system.
 486
 487 config SCHED_OMIT_FRAME_POINTER
 488         def_bool y
 489         prompt "Single-depth WCHAN output"
 490         depends on X86
 491         ---help---
 492           Calculate simpler /proc/<PID>/wchan values. If this option
 493           is disabled then wchan values will recurse back to the
 494           caller function. This provides more accurate wchan values,
 495           at the expense of slightly more scheduling overhead.
 496
 497           If in doubt, say "Y".
 498
 499 menuconfig PARAVIRT_GUEST
 500         bool "Paravirtualized guest support"
 501         ---help---
 502           Say Y here to get to see options related to running Linux under
 503           various hypervisors.  This option alone does not add any kernel code.
 504
 505           If you say N, all options in this submenu will be skipped and disabled.
 506
 507 if PARAVIRT_GUEST
 508
 509 source "arch/x86/xen/Kconfig"
 510
 511 config VMI
 512         bool "VMI Guest support (DEPRECATED)"
 513         select PARAVIRT
 514         depends on X86_32
 515         ---help---
 516           VMI provides a paravirtualized interface to the VMware ESX server
 517           (it could be used by other hypervisors in theory too, but is not
 518           at the moment), by linking the kernel to a GPL-ed ROM module
 519           provided by the hypervisor.
 520
 521           As of September 2009, VMware has started a phased retirement
 522           of this feature from VMware's products. Please see
 523           feature-removal-schedule.txt for details.  If you are
 524           planning to enable this option, please note that you cannot
 525           live migrate a VMI enabled VM to a future VMware product,
 526           which doesn't support VMI. So if you expect your kernel to
 527           seamlessly migrate to newer VMware products, keep this
 528           disabled.
 529
 530 config KVM_CLOCK
 531         bool "KVM paravirtualized clock"
 532         select PARAVIRT
 533         select PARAVIRT_CLOCK
 534         ---help---
 535           Turning on this option will allow you to run a paravirtualized clock
 536           when running over the KVM hypervisor. Instead of relying on a PIT
 537           (or probably other) emulation by the underlying device model, the host
 538           provides the guest with timing infrastructure such as time of day, and
 539           system time
 540
 541 config KVM_GUEST
 542         bool "KVM Guest support"
 543         select PARAVIRT
 544         ---help---
 545           This option enables various optimizations for running under the KVM
 546           hypervisor.
 547
 548 source "arch/x86/lguest/Kconfig"
 549
 550 config PARAVIRT
 551         bool "Enable paravirtualization code"
 552         ---help---
 553           This changes the kernel so it can modify itself when it is run
 554           under a hypervisor, potentially improving performance significantly
 555           over full virtualization.  However, when run without a hypervisor
 556           the kernel is theoretically slower and slightly larger.
 557
 558 config PARAVIRT_SPINLOCKS
 559         bool "Paravirtualization layer for spinlocks"
 560         depends on PARAVIRT && SMP && EXPERIMENTAL
 561         ---help---
 562           Paravirtualized spinlocks allow a pvops backend to replace the
 563           spinlock implementation with something virtualization-friendly
 564           (for example, block the virtual CPU rather than spinning).
 565
 566           Unfortunately the downside is an up to 5% performance hit on
 567           native kernels, with various workloads.
 568
 569           If you are unsure how to answer this question, answer N.
 570
 571 config PARAVIRT_CLOCK
 572         bool
 573         default n
 574
 575 endif
 576
 577 config PARAVIRT_DEBUG
 578         bool "paravirt-ops debugging"
 579         depends on PARAVIRT && DEBUG_KERNEL
 580         ---help---
 581           Enable to debug paravirt_ops internals.  Specifically, BUG if
 582           a paravirt_op is missing when it is called.
 583
 584 config NO_BOOTMEM
 585         default y
 586         bool "Disable Bootmem code"
 587         ---help---
 588           Use early_res directly instead of bootmem before slab is ready.
 589                 - allocator (buddy) [generic]
 590                 - early allocator (bootmem) [generic]
 591                 - very early allocator (reserve_early*()) [x86]
 592                 - very very early allocator (early brk model) [x86]
 593           So reduce one layer between early allocator to final allocator
 594
 595
 596 config MEMTEST
 597         bool "Memtest"
 598         ---help---
 599           This option adds a kernel parameter 'memtest', which allows memtest
 600           to be set.
 601                 memtest=0, mean disabled; -- default
 602                 memtest=1, mean do 1 test pattern;
 603                 ...
 604                 memtest=4, mean do 4 test patterns.
 605           If you are unsure how to answer this question, answer N.
 606
 607 config X86_SUMMIT_NUMA
 608         def_bool y
 609         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 610
 611 config X86_CYCLONE_TIMER
 612         def_bool y
 613         depends on X86_32_NON_STANDARD
 614
 615 source "arch/x86/Kconfig.cpu"
 616
 617 config HPET_TIMER
 618         def_bool X86_64
 619         prompt "HPET Timer Support" if X86_32
 620         ---help---
 621           Use the IA-PC HPET (High Precision Event Timer) to manage
 622           time in preference to the PIT and RTC, if a HPET is
 623           present.
 624           HPET is the next generation timer replacing legacy 8254s.
 625           The HPET provides a stable time base on SMP
 626           systems, unlike the TSC, but it is more expensive to access,
 627           as it is off-chip.  You can find the HPET spec at
 628           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 629
 630           You can safely choose Y here.  However, HPET will only be
 631           activated if the platform and the BIOS support this feature.
 632           Otherwise the 8254 will be used for timing services.
 633
 634           Choose N to continue using the legacy 8254 timer.
 635
 636 config HPET_EMULATE_RTC
 637         def_bool y
 638         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 639
 640 config APB_TIMER
 641        def_bool y if MRST
 642        prompt "Langwell APB Timer Support" if X86_MRST
 643        help
 644          APB timer is the replacement for 8254, HPET on X86 MID platforms.
 645          The APBT provides a stable time base on SMP
 646          systems, unlike the TSC, but it is more expensive to access,
 647          as it is off-chip. APB timers are always running regardless of CPU
 648          C states, they are used as per CPU clockevent device when possible.
 649
 650 # Mark as embedded because too many people got it wrong.
 651 # The code disables itself when not needed.
 652 config DMI
 653         default y
 654         bool "Enable DMI scanning" if EMBEDDED
 655         ---help---
 656           Enabled scanning of DMI to identify machine quirks. Say Y
 657           here unless you have verified that your setup is not
 658           affected by entries in the DMI blacklist. Required by PNP
 659           BIOS code.
 660
 661 config GART_IOMMU
 662         bool "GART IOMMU support" if EMBEDDED
 663         default y
 664         select SWIOTLB
 665         depends on X86_64 && PCI && K8_NB
 666         ---help---
 667           Support for full DMA access of devices with 32bit memory access only
 668           on systems with more than 3GB. This is usually needed for USB,
 669           sound, many IDE/SATA chipsets and some other devices.
 670           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 671           based hardware IOMMU and a software bounce buffer based IOMMU used
 672           on Intel systems and as fallback.
 673           The code is only active when needed (enough memory and limited
 674           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 675           too.
 676
 677 config CALGARY_IOMMU
 678         bool "IBM Calgary IOMMU support"
 679         select SWIOTLB
 680         depends on X86_64 && PCI && EXPERIMENTAL
 681         ---help---
 682           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 683           systems. Needed to run systems with more than 3GB of memory
 684           properly with 32-bit PCI devices that do not support DAC
 685           (Double Address Cycle). Calgary also supports bus level
 686           isolation, where all DMAs pass through the IOMMU.  This
 687           prevents them from going anywhere except their intended
 688           destination. This catches hard-to-find kernel bugs and
 689           mis-behaving drivers and devices that do not use the DMA-API
 690           properly to set up their DMA buffers.  The IOMMU can be
 691           turned off at boot time with the iommu=off parameter.
 692           Normally the kernel will make the right choice by itself.
 693           If unsure, say Y.
 694
 695 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 696         def_bool y
 697         prompt "Should Calgary be enabled by default?"
 698         depends on CALGARY_IOMMU
 699         ---help---
 700           Should Calgary be enabled by default? if you choose 'y', Calgary
 701           will be used (if it exists). If you choose 'n', Calgary will not be
 702           used even if it exists. If you choose 'n' and would like to use
 703           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 704           If unsure, say Y.
 705
 706 config AMD_IOMMU
 707         bool "AMD IOMMU support"
 708         select SWIOTLB
 709         select PCI_MSI
 710         depends on X86_64 && PCI && ACPI
 711         ---help---
 712           With this option you can enable support for AMD IOMMU hardware in
 713           your system. An IOMMU is a hardware component which provides
 714           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 715           can isolate the the DMA memory of different devices and protect the
 716           system from misbehaving device drivers or hardware.
 717
 718           You can find out if your system has an AMD IOMMU if you look into
 719           your BIOS for an option to enable it or if you have an IVRS ACPI
 720           table.
 721
 722 config AMD_IOMMU_STATS
 723         bool "Export AMD IOMMU statistics to debugfs"
 724         depends on AMD_IOMMU
 725         select DEBUG_FS
 726         ---help---
 727           This option enables code in the AMD IOMMU driver to collect various
 728           statistics about whats happening in the driver and exports that
 729           information to userspace via debugfs.
 730           If unsure, say N.
 731
 732 # need this always selected by IOMMU for the VIA workaround
 733 config SWIOTLB
 734         def_bool y if X86_64
 735         ---help---
 736           Support for software bounce buffers used on x86-64 systems
 737           which don't have a hardware IOMMU (e.g. the current generation
 738           of Intel's x86-64 CPUs). Using this PCI devices which can only
 739           access 32-bits of memory can be used on systems with more than
 740           3 GB of memory. If unsure, say Y.
 741
 742 config IOMMU_HELPER
 743         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 744
 745 config IOMMU_API
 746         def_bool (AMD_IOMMU || DMAR)
 747
 748 config MAXSMP
 749         bool "Configure Maximum number of SMP Processors and NUMA Nodes"
 750         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 751         select CPUMASK_OFFSTACK
 752         default n
 753         ---help---
 754           Configure maximum number of CPUS and NUMA Nodes for this architecture.
 755           If unsure, say N.
 756
 757 config NR_CPUS
 758         int "Maximum number of CPUs" if SMP && !MAXSMP
 759         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 760         range 2 512 if SMP && !MAXSMP
 761         default "1" if !SMP
 762         default "4096" if MAXSMP
 763         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 764         default "8" if SMP
 765         ---help---
 766           This allows you to specify the maximum number of CPUs which this
 767           kernel will support.  The maximum supported value is 512 and the
 768           minimum value which makes sense is 2.
 769
 770           This is purely to save memory - each supported CPU adds
 771           approximately eight kilobytes to the kernel image.
 772
 773 config SCHED_SMT
 774         bool "SMT (Hyperthreading) scheduler support"
 775         depends on X86_HT
 776         ---help---
 777           SMT scheduler support improves the CPU scheduler's decision making
 778           when dealing with Intel Pentium 4 chips with HyperThreading at a
 779           cost of slightly increased overhead in some places. If unsure say
 780           N here.
 781
 782 config SCHED_MC
 783         def_bool y
 784         prompt "Multi-core scheduler support"
 785         depends on X86_HT
 786         ---help---
 787           Multi-core scheduler support improves the CPU scheduler's decision
 788           making when dealing with multi-core CPU chips at a cost of slightly
 789           increased overhead in some places. If unsure say N here.
 790
 791 source "kernel/Kconfig.preempt"
 792
 793 config X86_UP_APIC
 794         bool "Local APIC support on uniprocessors"
 795         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 796         ---help---
 797           A local APIC (Advanced Programmable Interrupt Controller) is an
 798           integrated interrupt controller in the CPU. If you have a single-CPU
 799           system which has a processor with a local APIC, you can say Y here to
 800           enable and use it. If you say Y here even though your machine doesn't
 801           have a local APIC, then the kernel will still run with no slowdown at
 802           all. The local APIC supports CPU-generated self-interrupts (timer,
 803           performance counters), and the NMI watchdog which detects hard
 804           lockups.
 805
 806 config X86_UP_IOAPIC
 807         bool "IO-APIC support on uniprocessors"
 808         depends on X86_UP_APIC
 809         ---help---
 810           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 811           SMP-capable replacement for PC-style interrupt controllers. Most
 812           SMP systems and many recent uniprocessor systems have one.
 813
 814           If you have a single-CPU system with an IO-APIC, you can say Y here
 815           to use it. If you say Y here even though your machine doesn't have
 816           an IO-APIC, then the kernel will still run with no slowdown at all.
 817
 818 config X86_LOCAL_APIC
 819         def_bool y
 820         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 821
 822 config X86_IO_APIC
 823         def_bool y
 824         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 825
 826 config X86_VISWS_APIC
 827         def_bool y
 828         depends on X86_32 && X86_VISWS
 829
 830 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 831         bool "Reroute for broken boot IRQs"
 832         default n
 833         depends on X86_IO_APIC
 834         ---help---
 835           This option enables a workaround that fixes a source of
 836           spurious interrupts. This is recommended when threaded
 837           interrupt handling is used on systems where the generation of
 838           superfluous "boot interrupts" cannot be disabled.
 839
 840           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 841           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 842           kernel does during interrupt handling). On chipsets where this
 843           boot IRQ generation cannot be disabled, this workaround keeps
 844           the original IRQ line masked so that only the equivalent "boot
 845           IRQ" is delivered to the CPUs. The workaround also tells the
 846           kernel to set up the IRQ handler on the boot IRQ line. In this
 847           way only one interrupt is delivered to the kernel. Otherwise
 848           the spurious second interrupt may cause the kernel to bring
 849           down (vital) interrupt lines.
 850
 851           Only affects "broken" chipsets. Interrupt sharing may be
 852           increased on these systems.
 853
 854 config X86_MCE
 855         bool "Machine Check / overheating reporting"
 856         ---help---
 857           Machine Check support allows the processor to notify the
 858           kernel if it detects a problem (e.g. overheating, data corruption).
 859           The action the kernel takes depends on the severity of the problem,
 860           ranging from warning messages to halting the machine.
 861
 862 config X86_MCE_INTEL
 863         def_bool y
 864         prompt "Intel MCE features"
 865         depends on X86_MCE && X86_LOCAL_APIC
 866         ---help---
 867            Additional support for intel specific MCE features such as
 868            the thermal monitor.
 869
 870 config X86_MCE_AMD
 871         def_bool y
 872         prompt "AMD MCE features"
 873         depends on X86_MCE && X86_LOCAL_APIC
 874         ---help---
 875            Additional support for AMD specific MCE features such as
 876            the DRAM Error Threshold.
 877
 878 config X86_ANCIENT_MCE
 879         def_bool n
 880         depends on X86_32 && X86_MCE
 881         prompt "Support for old Pentium 5 / WinChip machine checks"
 882         ---help---
 883           Include support for machine check handling on old Pentium 5 or WinChip
 884           systems. These typically need to be enabled explicitely on the command
 885           line.
 886
 887 config X86_MCE_THRESHOLD
 888         depends on X86_MCE_AMD || X86_MCE_INTEL
 889         bool
 890         default y
 891
 892 config X86_MCE_INJECT
 893         depends on X86_MCE
 894         tristate "Machine check injector support"
 895         ---help---
 896           Provide support for injecting machine checks for testing purposes.
 897           If you don't know what a machine check is and you don't do kernel
 898           QA it is safe to say n.
 899
 900 config X86_THERMAL_VECTOR
 901         def_bool y
 902         depends on X86_MCE_INTEL
 903
 904 config VM86
 905         bool "Enable VM86 support" if EMBEDDED
 906         default y
 907         depends on X86_32
 908         ---help---
 909           This option is required by programs like DOSEMU to run 16-bit legacy
 910           code on X86 processors. It also may be needed by software like
 911           XFree86 to initialize some video cards via BIOS. Disabling this
 912           option saves about 6k.
 913
 914 config TOSHIBA
 915         tristate "Toshiba Laptop support"
 916         depends on X86_32
 917         ---help---
 918           This adds a driver to safely access the System Management Mode of
 919           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 920           not work on models with a Phoenix BIOS. The System Management Mode
 921           is used to set the BIOS and power saving options on Toshiba portables.
 922
 923           For information on utilities to make use of this driver see the
 924           Toshiba Linux utilities web site at:
 925           <http://www.buzzard.org.uk/toshiba/>.
 926
 927           Say Y if you intend to run this kernel on a Toshiba portable.
 928           Say N otherwise.
 929
 930 config I8K
 931         tristate "Dell laptop support"
 932         ---help---
 933           This adds a driver to safely access the System Management Mode
 934           of the CPU on the Dell Inspiron 8000. The System Management Mode
 935           is used to read cpu temperature and cooling fan status and to
 936           control the fans on the I8K portables.
 937
 938           This driver has been tested only on the Inspiron 8000 but it may
 939           also work with other Dell laptops. You can force loading on other
 940           models by passing the parameter `force=1' to the module. Use at
 941           your own risk.
 942
 943           For information on utilities to make use of this driver see the
 944           I8K Linux utilities web site at:
 945           <http://people.debian.org/~dz/i8k/>
 946
 947           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 948           Say N otherwise.
 949
 950 config X86_REBOOTFIXUPS
 951         bool "Enable X86 board specific fixups for reboot"
 952         depends on X86_32
 953         ---help---
 954           This enables chipset and/or board specific fixups to be done
 955           in order to get reboot to work correctly. This is only needed on
 956           some combinations of hardware and BIOS. The symptom, for which
 957           this config is intended, is when reboot ends with a stalled/hung
 958           system.
 959
 960           Currently, the only fixup is for the Geode machines using
 961           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 962
 963           Say Y if you want to enable the fixup. Currently, it's safe to
 964           enable this option even if you don't need it.
 965           Say N otherwise.
 966
 967 config MICROCODE
 968         tristate "/dev/cpu/microcode - microcode support"
 969         select FW_LOADER
 970         ---help---
 971           If you say Y here, you will be able to update the microcode on
 972           certain Intel and AMD processors. The Intel support is for the
 973           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 974           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 975           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 976           You will obviously need the actual microcode binary data itself
 977           which is not shipped with the Linux kernel.
 978
 979           This option selects the general module only, you need to select
 980           at least one vendor specific module as well.
 981
 982           To compile this driver as a module, choose M here: the
 983           module will be called microcode.
 984
 985 config MICROCODE_INTEL
 986         bool "Intel microcode patch loading support"
 987         depends on MICROCODE
 988         default MICROCODE
 989         select FW_LOADER
 990         ---help---
 991           This options enables microcode patch loading support for Intel
 992           processors.
 993
 994           For latest news and information on obtaining all the required
 995           Intel ingredients for this driver, check:
 996           <http://www.urbanmyth.org/microcode/>.
 997
 998 config MICROCODE_AMD
 999         bool "AMD microcode patch loading support"
1000         depends on MICROCODE
1001         select FW_LOADER
1002         ---help---
1003           If you select this option, microcode patch loading support for AMD
1004           processors will be enabled.
1005
1006 config MICROCODE_OLD_INTERFACE
1007         def_bool y
1008         depends on MICROCODE
1009
1010 config X86_MSR
1011         tristate "/dev/cpu/*/msr - Model-specific register support"
1012         ---help---
1013           This device gives privileged processes access to the x86
1014           Model-Specific Registers (MSRs).  It is a character device with
1015           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1016           MSR accesses are directed to a specific CPU on multi-processor
1017           systems.
1018
1019 config X86_CPUID
1020         tristate "/dev/cpu/*/cpuid - CPU information support"
1021         ---help---
1022           This device gives processes access to the x86 CPUID instruction to
1023           be executed on a specific processor.  It is a character device
1024           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1025           /dev/cpu/31/cpuid.
1026
1027 choice
1028         prompt "High Memory Support"
1029         default HIGHMEM4G if !X86_NUMAQ
1030         default HIGHMEM64G if X86_NUMAQ
1031         depends on X86_32
1032
1033 config NOHIGHMEM
1034         bool "off"
1035         depends on !X86_NUMAQ
1036         ---help---
1037           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1038           However, the address space of 32-bit x86 processors is only 4
1039           Gigabytes large. That means that, if you have a large amount of
1040           physical memory, not all of it can be "permanently mapped" by the
1041           kernel. The physical memory that's not permanently mapped is called
1042           "high memory".
1043
1044           If you are compiling a kernel which will never run on a machine with
1045           more than 1 Gigabyte total physical RAM, answer "off" here (default
1046           choice and suitable for most users). This will result in a "3GB/1GB"
1047           split: 3GB are mapped so that each process sees a 3GB virtual memory
1048           space and the remaining part of the 4GB virtual memory space is used
1049           by the kernel to permanently map as much physical memory as
1050           possible.
1051
1052           If the machine has between 1 and 4 Gigabytes physical RAM, then
1053           answer "4GB" here.
1054
1055           If more than 4 Gigabytes is used then answer "64GB" here. This
1056           selection turns Intel PAE (Physical Address Extension) mode on.
1057           PAE implements 3-level paging on IA32 processors. PAE is fully
1058           supported by Linux, PAE mode is implemented on all recent Intel
1059           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1060           then the kernel will not boot on CPUs that don't support PAE!
1061
1062           The actual amount of total physical memory will either be
1063           auto detected or can be forced by using a kernel command line option
1064           such as "mem=256M". (Try "man bootparam" or see the documentation of
1065           your boot loader (lilo or loadlin) about how to pass options to the
1066           kernel at boot time.)
1067
1068           If unsure, say "off".
1069
1070 config HIGHMEM4G
1071         bool "4GB"
1072         depends on !X86_NUMAQ
1073         ---help---
1074           Select this if you have a 32-bit processor and between 1 and 4
1075           gigabytes of physical RAM.
1076
1077 config HIGHMEM64G
1078         bool "64GB"
1079         depends on !M386 && !M486
1080         select X86_PAE
1081         ---help---
1082           Select this if you have a 32-bit processor and more than 4
1083           gigabytes of physical RAM.
1084
1085 endchoice
1086
1087 choice
1088         depends on EXPERIMENTAL
1089         prompt "Memory split" if EMBEDDED
1090         default VMSPLIT_3G
1091         depends on X86_32
1092         ---help---
1093           Select the desired split between kernel and user memory.
1094
1095           If the address range available to the kernel is less than the
1096           physical memory installed, the remaining memory will be available
1097           as "high memory". Accessing high memory is a little more costly
1098           than low memory, as it needs to be mapped into the kernel first.
1099           Note that increasing the kernel address space limits the range
1100           available to user programs, making the address space there
1101           tighter.  Selecting anything other than the default 3G/1G split
1102           will also likely make your kernel incompatible with binary-only
1103           kernel modules.
1104
1105           If you are not absolutely sure what you are doing, leave this
1106           option alone!
1107
1108         config VMSPLIT_3G
1109                 bool "3G/1G user/kernel split"
1110         config VMSPLIT_3G_OPT
1111                 depends on !X86_PAE
1112                 bool "3G/1G user/kernel split (for full 1G low memory)"
1113         config VMSPLIT_2G
1114                 bool "2G/2G user/kernel split"
1115         config VMSPLIT_2G_OPT
1116                 depends on !X86_PAE
1117                 bool "2G/2G user/kernel split (for full 2G low memory)"
1118         config VMSPLIT_1G
1119                 bool "1G/3G user/kernel split"
1120 endchoice
1121
1122 config PAGE_OFFSET
1123         hex
1124         default 0xB0000000 if VMSPLIT_3G_OPT
1125         default 0x80000000 if VMSPLIT_2G
1126         default 0x78000000 if VMSPLIT_2G_OPT
1127         default 0x40000000 if VMSPLIT_1G
1128         default 0xC0000000
1129         depends on X86_32
1130
1131 config HIGHMEM
1132         def_bool y
1133         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1134
1135 config X86_PAE
1136         bool "PAE (Physical Address Extension) Support"
1137         depends on X86_32 && !HIGHMEM4G
1138         ---help---
1139           PAE is required for NX support, and furthermore enables
1140           larger swapspace support for non-overcommit purposes. It
1141           has the cost of more pagetable lookup overhead, and also
1142           consumes more pagetable space per process.
1143
1144 config ARCH_PHYS_ADDR_T_64BIT
1145         def_bool X86_64 || X86_PAE
1146
1147 config DIRECT_GBPAGES
1148         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1149         default y
1150         depends on X86_64
1151         ---help---
1152           Allow the kernel linear mapping to use 1GB pages on CPUs that
1153           support it. This can improve the kernel's performance a tiny bit by
1154           reducing TLB pressure. If in doubt, say "Y".
1155
1156 # Common NUMA Features
1157 config NUMA
1158         bool "Numa Memory Allocation and Scheduler Support"
1159         depends on SMP
1160         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1161         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1162         ---help---
1163           Enable NUMA (Non Uniform Memory Access) support.
1164
1165           The kernel will try to allocate memory used by a CPU on the
1166           local memory controller of the CPU and add some more
1167           NUMA awareness to the kernel.
1168
1169           For 64-bit this is recommended if the system is Intel Core i7
1170           (or later), AMD Opteron, or EM64T NUMA.
1171
1172           For 32-bit this is only needed on (rare) 32-bit-only platforms
1173           that support NUMA topologies, such as NUMAQ / Summit, or if you
1174           boot a 32-bit kernel on a 64-bit NUMA platform.
1175
1176           Otherwise, you should say N.
1177
1178 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1179         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1180
1181 config K8_NUMA
1182         def_bool y
1183         prompt "Old style AMD Opteron NUMA detection"
1184         depends on X86_64 && NUMA && PCI
1185         ---help---
1186           Enable K8 NUMA node topology detection.  You should say Y here if
1187           you have a multi processor AMD K8 system. This uses an old
1188           method to read the NUMA configuration directly from the builtin
1189           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1190           instead, which also takes priority if both are compiled in.
1191
1192 config X86_64_ACPI_NUMA
1193         def_bool y
1194         prompt "ACPI NUMA detection"
1195         depends on X86_64 && NUMA && ACPI && PCI
1196         select ACPI_NUMA
1197         ---help---
1198           Enable ACPI SRAT based node topology detection.
1199
1200 # Some NUMA nodes have memory ranges that span
1201 # other nodes.  Even though a pfn is valid and
1202 # between a node's start and end pfns, it may not
1203 # reside on that node.  See memmap_init_zone()
1204 # for details.
1205 config NODES_SPAN_OTHER_NODES
1206         def_bool y
1207         depends on X86_64_ACPI_NUMA
1208
1209 config NUMA_EMU
1210         bool "NUMA emulation"
1211         depends on X86_64 && NUMA
1212         ---help---
1213           Enable NUMA emulation. A flat machine will be split
1214           into virtual nodes when booted with "numa=fake=N", where N is the
1215           number of nodes. This is only useful for debugging.
1216
1217 config NODES_SHIFT
1218         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1219         range 1 10
1220         default "10" if MAXSMP
1221         default "6" if X86_64
1222         default "4" if X86_NUMAQ
1223         default "3"
1224         depends on NEED_MULTIPLE_NODES
1225         ---help---
1226           Specify the maximum number of NUMA Nodes available on the target
1227           system.  Increases memory reserved to accommodate various tables.
1228
1229 config HAVE_ARCH_BOOTMEM
1230         def_bool y
1231         depends on X86_32 && NUMA
1232
1233 config ARCH_HAVE_MEMORY_PRESENT
1234         def_bool y
1235         depends on X86_32 && DISCONTIGMEM
1236
1237 config NEED_NODE_MEMMAP_SIZE
1238         def_bool y
1239         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1240
1241 config HAVE_ARCH_ALLOC_REMAP
1242         def_bool y
1243         depends on X86_32 && NUMA
1244
1245 config ARCH_FLATMEM_ENABLE
1246         def_bool y
1247         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1248
1249 config ARCH_DISCONTIGMEM_ENABLE
1250         def_bool y
1251         depends on NUMA && X86_32
1252
1253 config ARCH_DISCONTIGMEM_DEFAULT
1254         def_bool y
1255         depends on NUMA && X86_32
1256
1257 config ARCH_PROC_KCORE_TEXT
1258         def_bool y
1259         depends on X86_64 && PROC_KCORE
1260
1261 config ARCH_SPARSEMEM_DEFAULT
1262         def_bool y
1263         depends on X86_64
1264
1265 config ARCH_SPARSEMEM_ENABLE
1266         def_bool y
1267         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1268         select SPARSEMEM_STATIC if X86_32
1269         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1270
1271 config ARCH_SELECT_MEMORY_MODEL
1272         def_bool y
1273         depends on ARCH_SPARSEMEM_ENABLE
1274
1275 config ARCH_MEMORY_PROBE
1276         def_bool X86_64
1277         depends on MEMORY_HOTPLUG
1278
1279 config ILLEGAL_POINTER_VALUE
1280        hex
1281        default 0 if X86_32
1282        default 0xdead000000000000 if X86_64
1283
1284 source "mm/Kconfig"
1285
1286 config HIGHPTE
1287         bool "Allocate 3rd-level pagetables from highmem"
1288         depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1289         ---help---
1290           The VM uses one page table entry for each page of physical memory.
1291           For systems with a lot of RAM, this can be wasteful of precious
1292           low memory.  Setting this option will put user-space page table
1293           entries in high memory.
1294
1295 config X86_CHECK_BIOS_CORRUPTION
1296         bool "Check for low memory corruption"
1297         ---help---
1298           Periodically check for memory corruption in low memory, which
1299           is suspected to be caused by BIOS.  Even when enabled in the
1300           configuration, it is disabled at runtime.  Enable it by
1301           setting "memory_corruption_check=1" on the kernel command
1302           line.  By default it scans the low 64k of memory every 60
1303           seconds; see the memory_corruption_check_size and
1304           memory_corruption_check_period parameters in
1305           Documentation/kernel-parameters.txt to adjust this.
1306
1307           When enabled with the default parameters, this option has
1308           almost no overhead, as it reserves a relatively small amount
1309           of memory and scans it infrequently.  It both detects corruption
1310           and prevents it from affecting the running system.
1311
1312           It is, however, intended as a diagnostic tool; if repeatable
1313           BIOS-originated corruption always affects the same memory,
1314           you can use memmap= to prevent the kernel from using that
1315           memory.
1316
1317 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1318         bool "Set the default setting of memory_corruption_check"
1319         depends on X86_CHECK_BIOS_CORRUPTION
1320         default y
1321         ---help---
1322           Set whether the default state of memory_corruption_check is
1323           on or off.
1324
1325 config X86_RESERVE_LOW_64K
1326         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1327         default y
1328         ---help---
1329           Reserve the first 64K of physical RAM on BIOSes that are known
1330           to potentially corrupt that memory range. A numbers of BIOSes are
1331           known to utilize this area during suspend/resume, so it must not
1332           be used by the kernel.
1333
1334           Set this to N if you are absolutely sure that you trust the BIOS
1335           to get all its memory reservations and usages right.
1336
1337           If you have doubts about the BIOS (e.g. suspend/resume does not
1338           work or there's kernel crashes after certain hardware hotplug
1339           events) and it's not AMI or Phoenix, then you might want to enable
1340           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1341           corruption patterns.
1342
1343           Say Y if unsure.
1344
1345 config MATH_EMULATION
1346         bool
1347         prompt "Math emulation" if X86_32
1348         ---help---
1349           Linux can emulate a math coprocessor (used for floating point
1350           operations) if you don't have one. 486DX and Pentium processors have
1351           a math coprocessor built in, 486SX and 386 do not, unless you added
1352           a 487DX or 387, respectively. (The messages during boot time can
1353           give you some hints here ["man dmesg"].) Everyone needs either a
1354           coprocessor or this emulation.
1355
1356           If you don't have a math coprocessor, you need to say Y here; if you
1357           say Y here even though you have a coprocessor, the coprocessor will
1358           be used nevertheless. (This behavior can be changed with the kernel
1359           command line option "no387", which comes handy if your coprocessor
1360           is broken. Try "man bootparam" or see the documentation of your boot
1361           loader (lilo or loadlin) about how to pass options to the kernel at
1362           boot time.) This means that it is a good idea to say Y here if you
1363           intend to use this kernel on different machines.
1364
1365           More information about the internals of the Linux math coprocessor
1366           emulation can be found in <file:arch/x86/math-emu/README>.
1367
1368           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1369           kernel, it won't hurt.
1370
1371 config MTRR
1372         bool
1373         default y
1374         prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1375         ---help---
1376           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1377           the Memory Type Range Registers (MTRRs) may be used to control
1378           processor access to memory ranges. This is most useful if you have
1379           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1380           allows bus write transfers to be combined into a larger transfer
1381           before bursting over the PCI/AGP bus. This can increase performance
1382           of image write operations 2.5 times or more. Saying Y here creates a
1383           /proc/mtrr file which may be used to manipulate your processor's
1384           MTRRs. Typically the X server should use this.
1385
1386           This code has a reasonably generic interface so that similar
1387           control registers on other processors can be easily supported
1388           as well:
1389
1390           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1391           Registers (ARRs) which provide a similar functionality to MTRRs. For
1392           these, the ARRs are used to emulate the MTRRs.
1393           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1394           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1395           write-combining. All of these processors are supported by this code
1396           and it makes sense to say Y here if you have one of them.
1397
1398           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1399           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1400           can lead to all sorts of problems, so it's good to say Y here.
1401
1402           You can safely say Y even if your machine doesn't have MTRRs, you'll
1403           just add about 9 KB to your kernel.
1404
1405           See <file:Documentation/x86/mtrr.txt> for more information.
1406
1407 config MTRR_SANITIZER
1408         def_bool y
1409         prompt "MTRR cleanup support"
1410         depends on MTRR
1411         ---help---
1412           Convert MTRR layout from continuous to discrete, so X drivers can
1413           add writeback entries.
1414
1415           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1416           The largest mtrr entry size for a continuous block can be set with
1417           mtrr_chunk_size.
1418
1419           If unsure, say Y.
1420
1421 config MTRR_SANITIZER_ENABLE_DEFAULT
1422         int "MTRR cleanup enable value (0-1)"
1423         range 0 1
1424         default "0"
1425         depends on MTRR_SANITIZER
1426         ---help---
1427           Enable mtrr cleanup default value
1428
1429 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1430         int "MTRR cleanup spare reg num (0-7)"
1431         range 0 7
1432         default "1"
1433         depends on MTRR_SANITIZER
1434         ---help---
1435           mtrr cleanup spare entries default, it can be changed via
1436           mtrr_spare_reg_nr=N on the kernel command line.
1437
1438 config X86_PAT
1439         bool
1440         default y
1441         prompt "x86 PAT support" if EMBEDDED
1442         depends on MTRR
1443         ---help---
1444           Use PAT attributes to setup page level cache control.
1445
1446           PATs are the modern equivalents of MTRRs and are much more
1447           flexible than MTRRs.
1448
1449           Say N here if you see bootup problems (boot crash, boot hang,
1450           spontaneous reboots) or a non-working video driver.
1451
1452           If unsure, say Y.
1453
1454 config ARCH_USES_PG_UNCACHED
1455         def_bool y
1456         depends on X86_PAT
1457
1458 config EFI
1459         bool "EFI runtime service support"
1460         depends on ACPI
1461         ---help---
1462           This enables the kernel to use EFI runtime services that are
1463           available (such as the EFI variable services).
1464
1465           This option is only useful on systems that have EFI firmware.
1466           In addition, you should use the latest ELILO loader available
1467           at <http://elilo.sourceforge.net> in order to take advantage
1468           of EFI runtime services. However, even with this option, the
1469           resultant kernel should continue to boot on existing non-EFI
1470           platforms.
1471
1472 config SECCOMP
1473         def_bool y
1474         prompt "Enable seccomp to safely compute untrusted bytecode"
1475         ---help---
1476           This kernel feature is useful for number crunching applications
1477           that may need to compute untrusted bytecode during their
1478           execution. By using pipes or other transports made available to
1479           the process as file descriptors supporting the read/write
1480           syscalls, it's possible to isolate those applications in
1481           their own address space using seccomp. Once seccomp is
1482           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1483           and the task is only allowed to execute a few safe syscalls
1484           defined by each seccomp mode.
1485
1486           If unsure, say Y. Only embedded should say N here.
1487
1488 config CC_STACKPROTECTOR
1489         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1490         ---help---
1491           This option turns on the -fstack-protector GCC feature. This
1492           feature puts, at the beginning of functions, a canary value on
1493           the stack just before the return address, and validates
1494           the value just before actually returning.  Stack based buffer
1495           overflows (that need to overwrite this return address) now also
1496           overwrite the canary, which gets detected and the attack is then
1497           neutralized via a kernel panic.
1498
1499           This feature requires gcc version 4.2 or above, or a distribution
1500           gcc with the feature backported. Older versions are automatically
1501           detected and for those versions, this configuration option is
1502           ignored. (and a warning is printed during bootup)
1503
1504 source kernel/Kconfig.hz
1505
1506 config KEXEC
1507         bool "kexec system call"
1508         ---help---
1509           kexec is a system call that implements the ability to shutdown your
1510           current kernel, and to start another kernel.  It is like a reboot
1511           but it is independent of the system firmware.   And like a reboot
1512           you can start any kernel with it, not just Linux.
1513
1514           The name comes from the similarity to the exec system call.
1515
1516           It is an ongoing process to be certain the hardware in a machine
1517           is properly shutdown, so do not be surprised if this code does not
1518           initially work for you.  It may help to enable device hotplugging
1519           support.  As of this writing the exact hardware interface is
1520           strongly in flux, so no good recommendation can be made.
1521
1522 config CRASH_DUMP
1523         bool "kernel crash dumps"
1524         depends on X86_64 || (X86_32 && HIGHMEM)
1525         ---help---
1526           Generate crash dump after being started by kexec.
1527           This should be normally only set in special crash dump kernels
1528           which are loaded in the main kernel with kexec-tools into
1529           a specially reserved region and then later executed after
1530           a crash by kdump/kexec. The crash dump kernel must be compiled
1531           to a memory address not used by the main kernel or BIOS using
1532           PHYSICAL_START, or it must be built as a relocatable image
1533           (CONFIG_RELOCATABLE=y).
1534           For more details see Documentation/kdump/kdump.txt
1535
1536 config KEXEC_JUMP
1537         bool "kexec jump (EXPERIMENTAL)"
1538         depends on EXPERIMENTAL
1539         depends on KEXEC && HIBERNATION
1540         ---help---
1541           Jump between original kernel and kexeced kernel and invoke
1542           code in physical address mode via KEXEC
1543
1544 config PHYSICAL_START
1545         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1546         default "0x1000000"
1547         ---help---
1548           This gives the physical address where the kernel is loaded.
1549
1550           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1551           bzImage will decompress itself to above physical address and
1552           run from there. Otherwise, bzImage will run from the address where
1553           it has been loaded by the boot loader and will ignore above physical
1554           address.
1555
1556           In normal kdump cases one does not have to set/change this option
1557           as now bzImage can be compiled as a completely relocatable image
1558           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1559           address. This option is mainly useful for the folks who don't want
1560           to use a bzImage for capturing the crash dump and want to use a
1561           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1562           to be specifically compiled to run from a specific memory area
1563           (normally a reserved region) and this option comes handy.
1564
1565           So if you are using bzImage for capturing the crash dump,
1566           leave the value here unchanged to 0x1000000 and set
1567           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1568           for capturing the crash dump change this value to start of
1569           the reserved region.  In other words, it can be set based on
1570           the "X" value as specified in the "crashkernel=YM@XM"
1571           command line boot parameter passed to the panic-ed
1572           kernel. Please take a look at Documentation/kdump/kdump.txt
1573           for more details about crash dumps.
1574
1575           Usage of bzImage for capturing the crash dump is recommended as
1576           one does not have to build two kernels. Same kernel can be used
1577           as production kernel and capture kernel. Above option should have
1578           gone away after relocatable bzImage support is introduced. But it
1579           is present because there are users out there who continue to use
1580           vmlinux for dump capture. This option should go away down the
1581           line.
1582
1583           Don't change this unless you know what you are doing.
1584
1585 config RELOCATABLE
1586         bool "Build a relocatable kernel"
1587         default y
1588         ---help---
1589           This builds a kernel image that retains relocation information
1590           so it can be loaded someplace besides the default 1MB.
1591           The relocations tend to make the kernel binary about 10% larger,
1592           but are discarded at runtime.
1593
1594           One use is for the kexec on panic case where the recovery kernel
1595           must live at a different physical address than the primary
1596           kernel.
1597
1598           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1599           it has been loaded at and the compile time physical address
1600           (CONFIG_PHYSICAL_START) is ignored.
1601
1602 # Relocation on x86-32 needs some additional build support
1603 config X86_NEED_RELOCS
1604         def_bool y
1605         depends on X86_32 && RELOCATABLE
1606
1607 config PHYSICAL_ALIGN
1608         hex
1609         prompt "Alignment value to which kernel should be aligned" if X86_32
1610         default "0x1000000"
1611         range 0x2000 0x1000000
1612         ---help---
1613           This value puts the alignment restrictions on physical address
1614           where kernel is loaded and run from. Kernel is compiled for an
1615           address which meets above alignment restriction.
1616
1617           If bootloader loads the kernel at a non-aligned address and
1618           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1619           address aligned to above value and run from there.
1620
1621           If bootloader loads the kernel at a non-aligned address and
1622           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1623           load address and decompress itself to the address it has been
1624           compiled for and run from there. The address for which kernel is
1625           compiled already meets above alignment restrictions. Hence the
1626           end result is that kernel runs from a physical address meeting
1627           above alignment restrictions.
1628
1629           Don't change this unless you know what you are doing.
1630
1631 config HOTPLUG_CPU
1632         bool "Support for hot-pluggable CPUs"
1633         depends on SMP && HOTPLUG
1634         ---help---
1635           Say Y here to allow turning CPUs off and on. CPUs can be
1636           controlled through /sys/devices/system/cpu.
1637           ( Note: power management support will enable this option
1638             automatically on SMP systems. )
1639           Say N if you want to disable CPU hotplug.
1640
1641 config COMPAT_VDSO
1642         def_bool y
1643         prompt "Compat VDSO support"
1644         depends on X86_32 || IA32_EMULATION
1645         ---help---
1646           Map the 32-bit VDSO to the predictable old-style address too.
1647
1648           Say N here if you are running a sufficiently recent glibc
1649           version (2.3.3 or later), to remove the high-mapped
1650           VDSO mapping and to exclusively use the randomized VDSO.
1651
1652           If unsure, say Y.
1653
1654 config CMDLINE_BOOL
1655         bool "Built-in kernel command line"
1656         default n
1657         ---help---
1658           Allow for specifying boot arguments to the kernel at
1659           build time.  On some systems (e.g. embedded ones), it is
1660           necessary or convenient to provide some or all of the
1661           kernel boot arguments with the kernel itself (that is,
1662           to not rely on the boot loader to provide them.)
1663
1664           To compile command line arguments into the kernel,
1665           set this option to 'Y', then fill in the
1666           the boot arguments in CONFIG_CMDLINE.
1667
1668           Systems with fully functional boot loaders (i.e. non-embedded)
1669           should leave this option set to 'N'.
1670
1671 config CMDLINE
1672         string "Built-in kernel command string"
1673         depends on CMDLINE_BOOL
1674         default ""
1675         ---help---
1676           Enter arguments here that should be compiled into the kernel
1677           image and used at boot time.  If the boot loader provides a
1678           command line at boot time, it is appended to this string to
1679           form the full kernel command line, when the system boots.
1680
1681           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1682           change this behavior.
1683
1684           In most cases, the command line (whether built-in or provided
1685           by the boot loader) should specify the device for the root
1686           file system.
1687
1688 config CMDLINE_OVERRIDE
1689         bool "Built-in command line overrides boot loader arguments"
1690         default n
1691         depends on CMDLINE_BOOL
1692         ---help---
1693           Set this option to 'Y' to have the kernel ignore the boot loader
1694           command line, and use ONLY the built-in command line.
1695
1696           This is used to work around broken boot loaders.  This should
1697           be set to 'N' under normal conditions.
1698
1699 endmenu
1700
1701 config ARCH_ENABLE_MEMORY_HOTPLUG
1702         def_bool y
1703         depends on X86_64 || (X86_32 && HIGHMEM)
1704
1705 config ARCH_ENABLE_MEMORY_HOTREMOVE
1706         def_bool y
1707         depends on MEMORY_HOTPLUG
1708
1709 config HAVE_ARCH_EARLY_PFN_TO_NID
1710         def_bool X86_64
1711         depends on NUMA
1712
1713 menu "Power management and ACPI options"
1714
1715 config ARCH_HIBERNATION_HEADER
1716         def_bool y
1717         depends on X86_64 && HIBERNATION
1718
1719 source "kernel/power/Kconfig"
1720
1721 source "drivers/acpi/Kconfig"
1722
1723 source "drivers/sfi/Kconfig"
1724
1725 config X86_APM_BOOT
1726         bool
1727         default y
1728         depends on APM || APM_MODULE
1729
1730 menuconfig APM
1731         tristate "APM (Advanced Power Management) BIOS support"
1732         depends on X86_32 && PM_SLEEP
1733         ---help---
1734           APM is a BIOS specification for saving power using several different
1735           techniques. This is mostly useful for battery powered laptops with
1736           APM compliant BIOSes. If you say Y here, the system time will be
1737           reset after a RESUME operation, the /proc/apm device will provide
1738           battery status information, and user-space programs will receive
1739           notification of APM "events" (e.g. battery status change).
1740
1741           If you select "Y" here, you can disable actual use of the APM
1742           BIOS by passing the "apm=off" option to the kernel at boot time.
1743
1744           Note that the APM support is almost completely disabled for
1745           machines with more than one CPU.
1746
1747           In order to use APM, you will need supporting software. For location
1748           and more information, read <file:Documentation/power/pm.txt> and the
1749           Battery Powered Linux mini-HOWTO, available from
1750           <http://www.tldp.org/docs.html#howto>.
1751
1752           This driver does not spin down disk drives (see the hdparm(8)
1753           manpage ("man 8 hdparm") for that), and it doesn't turn off
1754           VESA-compliant "green" monitors.
1755
1756           This driver does not support the TI 4000M TravelMate and the ACER
1757           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1758           desktop machines also don't have compliant BIOSes, and this driver
1759           may cause those machines to panic during the boot phase.
1760
1761           Generally, if you don't have a battery in your machine, there isn't
1762           much point in using this driver and you should say N. If you get
1763           random kernel OOPSes or reboots that don't seem to be related to
1764           anything, try disabling/enabling this option (or disabling/enabling
1765           APM in your BIOS).
1766
1767           Some other things you should try when experiencing seemingly random,
1768           "weird" problems:
1769
1770           1) make sure that you have enough swap space and that it is
1771           enabled.
1772           2) pass the "no-hlt" option to the kernel
1773           3) switch on floating point emulation in the kernel and pass
1774           the "no387" option to the kernel
1775           4) pass the "floppy=nodma" option to the kernel
1776           5) pass the "mem=4M" option to the kernel (thereby disabling
1777           all but the first 4 MB of RAM)
1778           6) make sure that the CPU is not over clocked.
1779           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1780           8) disable the cache from your BIOS settings
1781           9) install a fan for the video card or exchange video RAM
1782           10) install a better fan for the CPU
1783           11) exchange RAM chips
1784           12) exchange the motherboard.
1785
1786           To compile this driver as a module, choose M here: the
1787           module will be called apm.
1788
1789 if APM
1790
1791 config APM_IGNORE_USER_SUSPEND
1792         bool "Ignore USER SUSPEND"
1793         ---help---
1794           This option will ignore USER SUSPEND requests. On machines with a
1795           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1796           series notebooks, it is necessary to say Y because of a BIOS bug.
1797
1798 config APM_DO_ENABLE
1799         bool "Enable PM at boot time"
1800         ---help---
1801           Enable APM features at boot time. From page 36 of the APM BIOS
1802           specification: "When disabled, the APM BIOS does not automatically
1803           power manage devices, enter the Standby State, enter the Suspend
1804           State, or take power saving steps in response to CPU Idle calls."
1805           This driver will make CPU Idle calls when Linux is idle (unless this
1806           feature is turned off -- see "Do CPU IDLE calls", below). This
1807           should always save battery power, but more complicated APM features
1808           will be dependent on your BIOS implementation. You may need to turn
1809           this option off if your computer hangs at boot time when using APM
1810           support, or if it beeps continuously instead of suspending. Turn
1811           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1812           T400CDT. This is off by default since most machines do fine without
1813           this feature.
1814
1815 config APM_CPU_IDLE
1816         bool "Make CPU Idle calls when idle"
1817         ---help---
1818           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1819           On some machines, this can activate improved power savings, such as
1820           a slowed CPU clock rate, when the machine is idle. These idle calls
1821           are made after the idle loop has run for some length of time (e.g.,
1822           333 mS). On some machines, this will cause a hang at boot time or
1823           whenever the CPU becomes idle. (On machines with more than one CPU,
1824           this option does nothing.)
1825
1826 config APM_DISPLAY_BLANK
1827         bool "Enable console blanking using APM"
1828         ---help---
1829           Enable console blanking using the APM. Some laptops can use this to
1830           turn off the LCD backlight when the screen blanker of the Linux
1831           virtual console blanks the screen. Note that this is only used by
1832           the virtual console screen blanker, and won't turn off the backlight
1833           when using the X Window system. This also doesn't have anything to
1834           do with your VESA-compliant power-saving monitor. Further, this
1835           option doesn't work for all laptops -- it might not turn off your
1836           backlight at all, or it might print a lot of errors to the console,
1837           especially if you are using gpm.
1838
1839 config APM_ALLOW_INTS
1840         bool "Allow interrupts during APM BIOS calls"
1841         ---help---
1842           Normally we disable external interrupts while we are making calls to
1843           the APM BIOS as a measure to lessen the effects of a badly behaving
1844           BIOS implementation.  The BIOS should reenable interrupts if it
1845           needs to.  Unfortunately, some BIOSes do not -- especially those in
1846           many of the newer IBM Thinkpads.  If you experience hangs when you
1847           suspend, try setting this to Y.  Otherwise, say N.
1848
1849 endif # APM
1850
1851 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1852
1853 source "drivers/cpuidle/Kconfig"
1854
1855 source "drivers/idle/Kconfig"
1856
1857 endmenu
1858
1859
1860 menu "Bus options (PCI etc.)"
1861
1862 config PCI
1863         bool "PCI support"
1864         default y
1865         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1866         ---help---
1867           Find out whether you have a PCI motherboard. PCI is the name of a
1868           bus system, i.e. the way the CPU talks to the other stuff inside
1869           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1870           VESA. If you have PCI, say Y, otherwise N.
1871
1872 choice
1873         prompt "PCI access mode"
1874         depends on X86_32 && PCI
1875         default PCI_GOANY
1876         ---help---
1877           On PCI systems, the BIOS can be used to detect the PCI devices and
1878           determine their configuration. However, some old PCI motherboards
1879           have BIOS bugs and may crash if this is done. Also, some embedded
1880           PCI-based systems don't have any BIOS at all. Linux can also try to
1881           detect the PCI hardware directly without using the BIOS.
1882
1883           With this option, you can specify how Linux should detect the
1884           PCI devices. If you choose "BIOS", the BIOS will be used,
1885           if you choose "Direct", the BIOS won't be used, and if you
1886           choose "MMConfig", then PCI Express MMCONFIG will be used.
1887           If you choose "Any", the kernel will try MMCONFIG, then the
1888           direct access method and falls back to the BIOS if that doesn't
1889           work. If unsure, go with the default, which is "Any".
1890
1891 config PCI_GOBIOS
1892         bool "BIOS"
1893
1894 config PCI_GOMMCONFIG
1895         bool "MMConfig"
1896
1897 config PCI_GODIRECT
1898         bool "Direct"
1899
1900 config PCI_GOOLPC
1901         bool "OLPC"
1902         depends on OLPC
1903
1904 config PCI_GOANY
1905         bool "Any"
1906
1907 endchoice
1908
1909 config PCI_BIOS
1910         def_bool y
1911         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1912
1913 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1914 config PCI_DIRECT
1915         def_bool y
1916         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1917
1918 config PCI_MMCONFIG
1919         def_bool y
1920         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1921
1922 config PCI_OLPC
1923         def_bool y
1924         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1925
1926 config PCI_DOMAINS
1927         def_bool y
1928         depends on PCI
1929
1930 config PCI_MMCONFIG
1931         bool "Support mmconfig PCI config space access"
1932         depends on X86_64 && PCI && ACPI
1933
1934 config DMAR
1935         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1936         depends on PCI_MSI && ACPI && EXPERIMENTAL
1937         help
1938           DMA remapping (DMAR) devices support enables independent address
1939           translations for Direct Memory Access (DMA) from devices.
1940           These DMA remapping devices are reported via ACPI tables
1941           and include PCI device scope covered by these DMA
1942           remapping devices.
1943
1944 config DMAR_DEFAULT_ON
1945         def_bool y
1946         prompt "Enable DMA Remapping Devices by default"
1947         depends on DMAR
1948         help
1949           Selecting this option will enable a DMAR device at boot time if
1950           one is found. If this option is not selected, DMAR support can
1951           be enabled by passing intel_iommu=on to the kernel. It is
1952           recommended you say N here while the DMAR code remains
1953           experimental.
1954
1955 config DMAR_BROKEN_GFX_WA
1956         def_bool n
1957         prompt "Workaround broken graphics drivers (going away soon)"
1958         depends on DMAR && BROKEN
1959         ---help---
1960           Current Graphics drivers tend to use physical address
1961           for DMA and avoid using DMA APIs. Setting this config
1962           option permits the IOMMU driver to set a unity map for
1963           all the OS-visible memory. Hence the driver can continue
1964           to use physical addresses for DMA, at least until this
1965           option is removed in the 2.6.32 kernel.
1966
1967 config DMAR_FLOPPY_WA
1968         def_bool y
1969         depends on DMAR
1970         ---help---
1971           Floppy disk drivers are known to bypass DMA API calls
1972           thereby failing to work when IOMMU is enabled. This
1973           workaround will setup a 1:1 mapping for the first
1974           16MiB to make floppy (an ISA device) work.
1975
1976 config INTR_REMAP
1977         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1978         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1979         ---help---
1980           Supports Interrupt remapping for IO-APIC and MSI devices.
1981           To use x2apic mode in the CPU's which support x2APIC enhancements or
1982           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1983
1984 source "drivers/pci/pcie/Kconfig"
1985
1986 source "drivers/pci/Kconfig"
1987
1988 # x86_64 have no ISA slots, but do have ISA-style DMA.
1989 config ISA_DMA_API
1990         def_bool y
1991
1992 if X86_32
1993
1994 config ISA
1995         bool "ISA support"
1996         ---help---
1997           Find out whether you have ISA slots on your motherboard.  ISA is the
1998           name of a bus system, i.e. the way the CPU talks to the other stuff
1999           inside your box.  Other bus systems are PCI, EISA, MicroChannel
2000           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2001           newer boards don't support it.  If you have ISA, say Y, otherwise N.
2002
2003 config EISA
2004         bool "EISA support"
2005         depends on ISA
2006         ---help---
2007           The Extended Industry Standard Architecture (EISA) bus was
2008           developed as an open alternative to the IBM MicroChannel bus.
2009
2010           The EISA bus provided some of the features of the IBM MicroChannel
2011           bus while maintaining backward compatibility with cards made for
2012           the older ISA bus.  The EISA bus saw limited use between 1988 and
2013           1995 when it was made obsolete by the PCI bus.
2014
2015           Say Y here if you are building a kernel for an EISA-based machine.
2016
2017           Otherwise, say N.
2018
2019 source "drivers/eisa/Kconfig"
2020
2021 config MCA
2022         bool "MCA support"
2023         ---help---
2024           MicroChannel Architecture is found in some IBM PS/2 machines and
2025           laptops.  It is a bus system similar to PCI or ISA. See
2026           <file:Documentation/mca.txt> (and especially the web page given
2027           there) before attempting to build an MCA bus kernel.
2028
2029 source "drivers/mca/Kconfig"
2030
2031 config SCx200
2032         tristate "NatSemi SCx200 support"
2033         ---help---
2034           This provides basic support for National Semiconductor's
2035           (now AMD's) Geode processors.  The driver probes for the
2036           PCI-IDs of several on-chip devices, so its a good dependency
2037           for other scx200_* drivers.
2038
2039           If compiled as a module, the driver is named scx200.
2040
2041 config SCx200HR_TIMER
2042         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2043         depends on SCx200 && GENERIC_TIME
2044         default y
2045         ---help---
2046           This driver provides a clocksource built upon the on-chip
2047           27MHz high-resolution timer.  Its also a workaround for
2048           NSC Geode SC-1100's buggy TSC, which loses time when the
2049           processor goes idle (as is done by the scheduler).  The
2050           other workaround is idle=poll boot option.
2051
2052 config OLPC
2053         bool "One Laptop Per Child support"
2054         select GPIOLIB
2055         default n
2056         ---help---
2057           Add support for detecting the unique features of the OLPC
2058           XO hardware.
2059
2060 endif # X86_32
2061
2062 config K8_NB
2063         def_bool y
2064         depends on CPU_SUP_AMD && PCI
2065
2066 source "drivers/pcmcia/Kconfig"
2067
2068 source "drivers/pci/hotplug/Kconfig"
2069
2070 endmenu
2071
2072
2073 menu "Executable file formats / Emulations"
2074
2075 source "fs/Kconfig.binfmt"
2076
2077 config IA32_EMULATION
2078         bool "IA32 Emulation"
2079         depends on X86_64
2080         select COMPAT_BINFMT_ELF
2081         ---help---
2082           Include code to run 32-bit programs under a 64-bit kernel. You should
2083           likely turn this on, unless you're 100% sure that you don't have any
2084           32-bit programs left.
2085
2086 config IA32_AOUT
2087         tristate "IA32 a.out support"
2088         depends on IA32_EMULATION
2089         ---help---
2090           Support old a.out binaries in the 32bit emulation.
2091
2092 config COMPAT
2093         def_bool y
2094         depends on IA32_EMULATION
2095
2096 config COMPAT_FOR_U64_ALIGNMENT
2097         def_bool COMPAT
2098         depends on X86_64
2099
2100 config SYSVIPC_COMPAT
2101         def_bool y
2102         depends on COMPAT && SYSVIPC
2103
2104 endmenu
2105
2106
2107 config HAVE_ATOMIC_IOMAP
2108         def_bool y
2109         depends on X86_32
2110
2111 source "net/Kconfig"
2112
2113 source "drivers/Kconfig"
2114
2115 source "drivers/firmware/Kconfig"
2116
2117 source "fs/Kconfig"
2118
2119 source "arch/x86/Kconfig.debug"
2120
2121 source "security/Kconfig"
2122
2123 source "crypto/Kconfig"
2124
2125 source "arch/x86/kvm/Kconfig"
2126
2127 source "lib/Kconfig"