arch/x86/Kconfig

   1 # Select 32 or 64 bit
   2 config 64BIT
   3         bool "64-bit kernel" if ARCH = "x86"
   4         default ARCH = "x86_64"
   5         ---help---
   6           Say yes to build a 64-bit kernel - formerly known as x86_64
   7           Say no to build a 32-bit kernel - formerly known as i386
   8
   9 config X86_32
  10         def_bool !64BIT
  11         select CLKSRC_I8253
  12
  13 config X86_64
  14         def_bool 64BIT
  15
  16 ### Arch settings
  17 config X86
  18         def_bool y
  19         select HAVE_AOUT if X86_32
  20         select HAVE_UNSTABLE_SCHED_CLOCK
  21         select HAVE_IDE
  22         select HAVE_OPROFILE
  23         select HAVE_PCSPKR_PLATFORM
  24         select HAVE_PERF_EVENTS
  25         select HAVE_IRQ_WORK
  26         select HAVE_IOREMAP_PROT
  27         select HAVE_KPROBES
  28         select HAVE_MEMBLOCK
  29         select ARCH_WANT_OPTIONAL_GPIOLIB
  30         select ARCH_WANT_FRAME_POINTERS
  31         select HAVE_DMA_ATTRS
  32         select HAVE_KRETPROBES
  33         select HAVE_OPTPROBES
  34         select HAVE_FTRACE_MCOUNT_RECORD
  35         select HAVE_C_RECORDMCOUNT
  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_XZ
  55         select HAVE_KERNEL_LZO
  56         select HAVE_HW_BREAKPOINT
  57         select HAVE_MIXED_BREAKPOINTS_REGS
  58         select PERF_EVENTS
  59         select HAVE_PERF_EVENTS_NMI
  60         select ANON_INODES
  61         select HAVE_ARCH_KMEMCHECK
  62         select HAVE_USER_RETURN_NOTIFIER
  63         select HAVE_ARCH_JUMP_LABEL
  64         select HAVE_TEXT_POKE_SMP
  65         select HAVE_GENERIC_HARDIRQS
  66         select HAVE_SPARSE_IRQ
  67         select GENERIC_FIND_FIRST_BIT
  68         select GENERIC_IRQ_PROBE
  69         select GENERIC_PENDING_IRQ if SMP
  70         select GENERIC_IRQ_SHOW
  71         select IRQ_FORCED_THREADING
  72         select USE_GENERIC_SMP_HELPERS if SMP
  73         select HAVE_BPF_JIT if (X86_64 && NET)
  74         select CLKEVT_I8253
  75
  76 config INSTRUCTION_DECODER
  77         def_bool (KPROBES || PERF_EVENTS)
  78
  79 config OUTPUT_FORMAT
  80         string
  81         default "elf32-i386" if X86_32
  82         default "elf64-x86-64" if X86_64
  83
  84 config ARCH_DEFCONFIG
  85         string
  86         default "arch/x86/configs/i386_defconfig" if X86_32
  87         default "arch/x86/configs/x86_64_defconfig" if X86_64
  88
  89 config GENERIC_CMOS_UPDATE
  90         def_bool y
  91
  92 config CLOCKSOURCE_WATCHDOG
  93         def_bool y
  94
  95 config GENERIC_CLOCKEVENTS
  96         def_bool y
  97
  98 config ARCH_CLOCKSOURCE_DATA
  99         def_bool y
 100         depends on X86_64
 101
 102 config GENERIC_CLOCKEVENTS_BROADCAST
 103         def_bool y
 104         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
 105
 106 config LOCKDEP_SUPPORT
 107         def_bool y
 108
 109 config STACKTRACE_SUPPORT
 110         def_bool y
 111
 112 config HAVE_LATENCYTOP_SUPPORT
 113         def_bool y
 114
 115 config MMU
 116         def_bool y
 117
 118 config ZONE_DMA
 119         bool "DMA memory allocation support" if EXPERT
 120         default y
 121         help
 122           DMA memory allocation support allows devices with less than 32-bit
 123           addressing to allocate within the first 16MB of address space.
 124           Disable if no such devices will be used.
 125
 126           If unsure, say Y.
 127
 128 config SBUS
 129         bool
 130
 131 config NEED_DMA_MAP_STATE
 132        def_bool (X86_64 || DMAR || DMA_API_DEBUG)
 133
 134 config NEED_SG_DMA_LENGTH
 135         def_bool y
 136
 137 config GENERIC_ISA_DMA
 138         def_bool ISA_DMA_API
 139
 140 config GENERIC_IOMAP
 141         def_bool y
 142
 143 config GENERIC_BUG
 144         def_bool y
 145         depends on BUG
 146         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 147
 148 config GENERIC_BUG_RELATIVE_POINTERS
 149         bool
 150
 151 config GENERIC_HWEIGHT
 152         def_bool y
 153
 154 config GENERIC_GPIO
 155         bool
 156
 157 config ARCH_MAY_HAVE_PC_FDC
 158         def_bool ISA_DMA_API
 159
 160 config RWSEM_GENERIC_SPINLOCK
 161         def_bool !X86_XADD
 162
 163 config RWSEM_XCHGADD_ALGORITHM
 164         def_bool X86_XADD
 165
 166 config ARCH_HAS_CPU_IDLE_WAIT
 167         def_bool y
 168
 169 config GENERIC_CALIBRATE_DELAY
 170         def_bool y
 171
 172 config GENERIC_TIME_VSYSCALL
 173         bool
 174         default X86_64
 175
 176 config ARCH_HAS_CPU_RELAX
 177         def_bool y
 178
 179 config ARCH_HAS_DEFAULT_IDLE
 180         def_bool y
 181
 182 config ARCH_HAS_CACHE_LINE_SIZE
 183         def_bool y
 184
 185 config HAVE_SETUP_PER_CPU_AREA
 186         def_bool y
 187
 188 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 189         def_bool y
 190
 191 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 192         def_bool y
 193
 194 config HAVE_CPUMASK_OF_CPU_MAP
 195         def_bool X86_64_SMP
 196
 197 config ARCH_HIBERNATION_POSSIBLE
 198         def_bool y
 199
 200 config ARCH_SUSPEND_POSSIBLE
 201         def_bool y
 202
 203 config ZONE_DMA32
 204         bool
 205         default X86_64
 206
 207 config ARCH_POPULATES_NODE_MAP
 208         def_bool y
 209
 210 config AUDIT_ARCH
 211         bool
 212         default X86_64
 213
 214 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 215         def_bool y
 216
 217 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 218         def_bool y
 219
 220 config HAVE_INTEL_TXT
 221         def_bool y
 222         depends on EXPERIMENTAL && DMAR && ACPI
 223
 224 config X86_32_SMP
 225         def_bool y
 226         depends on X86_32 && SMP
 227
 228 config X86_64_SMP
 229         def_bool y
 230         depends on X86_64 && SMP
 231
 232 config X86_HT
 233         def_bool y
 234         depends on SMP
 235
 236 config X86_32_LAZY_GS
 237         def_bool y
 238         depends on X86_32 && !CC_STACKPROTECTOR
 239
 240 config ARCH_HWEIGHT_CFLAGS
 241         string
 242         default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
 243         default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
 244
 245 config KTIME_SCALAR
 246         def_bool X86_32
 247
 248 config ARCH_CPU_PROBE_RELEASE
 249         def_bool y
 250         depends on HOTPLUG_CPU
 251
 252 source "init/Kconfig"
 253 source "kernel/Kconfig.freezer"
 254
 255 menu "Processor type and features"
 256
 257 source "kernel/time/Kconfig"
 258
 259 config SMP
 260         bool "Symmetric multi-processing support"
 261         ---help---
 262           This enables support for systems with more than one CPU. If you have
 263           a system with only one CPU, like most personal computers, say N. If
 264           you have a system with more than one CPU, say Y.
 265
 266           If you say N here, the kernel will run on single and multiprocessor
 267           machines, but will use only one CPU of a multiprocessor machine. If
 268           you say Y here, the kernel will run on many, but not all,
 269           singleprocessor machines. On a singleprocessor machine, the kernel
 270           will run faster if you say N here.
 271
 272           Note that if you say Y here and choose architecture "586" or
 273           "Pentium" under "Processor family", the kernel will not work on 486
 274           architectures. Similarly, multiprocessor kernels for the "PPro"
 275           architecture may not work on all Pentium based boards.
 276
 277           People using multiprocessor machines who say Y here should also say
 278           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 279           Management" code will be disabled if you say Y here.
 280
 281           See also <file:Documentation/i386/IO-APIC.txt>,
 282           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 283           <http://www.tldp.org/docs.html#howto>.
 284
 285           If you don't know what to do here, say N.
 286
 287 config X86_X2APIC
 288         bool "Support x2apic"
 289         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 290         ---help---
 291           This enables x2apic support on CPUs that have this feature.
 292
 293           This allows 32-bit apic IDs (so it can support very large systems),
 294           and accesses the local apic via MSRs not via mmio.
 295
 296           If you don't know what to do here, say N.
 297
 298 config X86_MPPARSE
 299         bool "Enable MPS table" if ACPI
 300         default y
 301         depends on X86_LOCAL_APIC
 302         ---help---
 303           For old smp systems that do not have proper acpi support. Newer systems
 304           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 305
 306 config X86_BIGSMP
 307         bool "Support for big SMP systems with more than 8 CPUs"
 308         depends on X86_32 && SMP
 309         ---help---
 310           This option is needed for the systems that have more than 8 CPUs
 311
 312 if X86_32
 313 config X86_EXTENDED_PLATFORM
 314         bool "Support for extended (non-PC) x86 platforms"
 315         default y
 316         ---help---
 317           If you disable this option then the kernel will only support
 318           standard PC platforms. (which covers the vast majority of
 319           systems out there.)
 320
 321           If you enable this option then you'll be able to select support
 322           for the following (non-PC) 32 bit x86 platforms:
 323                 AMD Elan
 324                 NUMAQ (IBM/Sequent)
 325                 RDC R-321x SoC
 326                 SGI 320/540 (Visual Workstation)
 327                 Summit/EXA (IBM x440)
 328                 Unisys ES7000 IA32 series
 329                 Moorestown MID devices
 330
 331           If you have one of these systems, or if you want to build a
 332           generic distribution kernel, say Y here - otherwise say N.
 333 endif
 334
 335 if X86_64
 336 config X86_EXTENDED_PLATFORM
 337         bool "Support for extended (non-PC) x86 platforms"
 338         default y
 339         ---help---
 340           If you disable this option then the kernel will only support
 341           standard PC platforms. (which covers the vast majority of
 342           systems out there.)
 343
 344           If you enable this option then you'll be able to select support
 345           for the following (non-PC) 64 bit x86 platforms:
 346                 ScaleMP vSMP
 347                 SGI Ultraviolet
 348
 349           If you have one of these systems, or if you want to build a
 350           generic distribution kernel, say Y here - otherwise say N.
 351 endif
 352 # This is an alphabetically sorted list of 64 bit extended platforms
 353 # Please maintain the alphabetic order if and when there are additions
 354
 355 config X86_VSMP
 356         bool "ScaleMP vSMP"
 357         select PARAVIRT_GUEST
 358         select PARAVIRT
 359         depends on X86_64 && PCI
 360         depends on X86_EXTENDED_PLATFORM
 361         ---help---
 362           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 363           supposed to run on these EM64T-based machines.  Only choose this option
 364           if you have one of these machines.
 365
 366 config X86_UV
 367         bool "SGI Ultraviolet"
 368         depends on X86_64
 369         depends on X86_EXTENDED_PLATFORM
 370         depends on NUMA
 371         depends on X86_X2APIC
 372         ---help---
 373           This option is needed in order to support SGI Ultraviolet systems.
 374           If you don't have one of these, you should say N here.
 375
 376 # Following is an alphabetically sorted list of 32 bit extended platforms
 377 # Please maintain the alphabetic order if and when there are additions
 378
 379 config X86_INTEL_CE
 380         bool "CE4100 TV platform"
 381         depends on PCI
 382         depends on PCI_GODIRECT
 383         depends on X86_32
 384         depends on X86_EXTENDED_PLATFORM
 385         select X86_REBOOTFIXUPS
 386         select OF
 387         select OF_EARLY_FLATTREE
 388         ---help---
 389           Select for the Intel CE media processor (CE4100) SOC.
 390           This option compiles in support for the CE4100 SOC for settop
 391           boxes and media devices.
 392
 393 config X86_INTEL_MID
 394         bool "Intel MID platform support"
 395         depends on X86_32
 396         depends on X86_EXTENDED_PLATFORM
 397         ---help---
 398           Select to build a kernel capable of supporting Intel MID platform
 399           systems which do not have the PCI legacy interfaces (Moorestown,
 400           Medfield). If you are building for a PC class system say N here.
 401
 402 if X86_INTEL_MID
 403
 404 config X86_MRST
 405        bool "Moorestown MID platform"
 406         depends on PCI
 407         depends on PCI_GOANY
 408         depends on X86_IO_APIC
 409         select APB_TIMER
 410         select I2C
 411         select SPI
 412         select INTEL_SCU_IPC
 413         select X86_PLATFORM_DEVICES
 414         ---help---
 415           Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 416           Internet Device(MID) platform. Moorestown consists of two chips:
 417           Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
 418           Unlike standard x86 PCs, Moorestown does not have many legacy devices
 419           nor standard legacy replacement devices/features. e.g. Moorestown does
 420           not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
 421
 422 endif
 423
 424 config X86_RDC321X
 425         bool "RDC R-321x SoC"
 426         depends on X86_32
 427         depends on X86_EXTENDED_PLATFORM
 428         select M486
 429         select X86_REBOOTFIXUPS
 430         ---help---
 431           This option is needed for RDC R-321x system-on-chip, also known
 432           as R-8610-(G).
 433           If you don't have one of these chips, you should say N here.
 434
 435 config X86_32_NON_STANDARD
 436         bool "Support non-standard 32-bit SMP architectures"
 437         depends on X86_32 && SMP
 438         depends on X86_EXTENDED_PLATFORM
 439         ---help---
 440           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 441           subarchitectures.  It is intended for a generic binary kernel.
 442           if you select them all, kernel will probe it one by one. and will
 443           fallback to default.
 444
 445 # Alphabetically sorted list of Non standard 32 bit platforms
 446
 447 config X86_NUMAQ
 448         bool "NUMAQ (IBM/Sequent)"
 449         depends on X86_32_NON_STANDARD
 450         depends on PCI
 451         select NUMA
 452         select X86_MPPARSE
 453         ---help---
 454           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 455           NUMA multiquad box. This changes the way that processors are
 456           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 457           of Flat Logical.  You will need a new lynxer.elf file to flash your
 458           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 459
 460 config X86_SUPPORTS_MEMORY_FAILURE
 461         def_bool y
 462         # MCE code calls memory_failure():
 463         depends on X86_MCE
 464         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
 465         depends on !X86_NUMAQ
 466         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
 467         depends on X86_64 || !SPARSEMEM
 468         select ARCH_SUPPORTS_MEMORY_FAILURE
 469
 470 config X86_VISWS
 471         bool "SGI 320/540 (Visual Workstation)"
 472         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 473         depends on X86_32_NON_STANDARD
 474         ---help---
 475           The SGI Visual Workstation series is an IA32-based workstation
 476           based on SGI systems chips with some legacy PC hardware attached.
 477
 478           Say Y here to create a kernel to run on the SGI 320 or 540.
 479
 480           A kernel compiled for the Visual Workstation will run on general
 481           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 482
 483 config X86_SUMMIT
 484         bool "Summit/EXA (IBM x440)"
 485         depends on X86_32_NON_STANDARD
 486         ---help---
 487           This option is needed for IBM systems that use the Summit/EXA chipset.
 488           In particular, it is needed for the x440.
 489
 490 config X86_ES7000
 491         bool "Unisys ES7000 IA32 series"
 492         depends on X86_32_NON_STANDARD && X86_BIGSMP
 493         ---help---
 494           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 495           supposed to run on an IA32-based Unisys ES7000 system.
 496
 497 config X86_32_IRIS
 498         tristate "Eurobraille/Iris poweroff module"
 499         depends on X86_32
 500         ---help---
 501           The Iris machines from EuroBraille do not have APM or ACPI support
 502           to shut themselves down properly.  A special I/O sequence is
 503           needed to do so, which is what this module does at
 504           kernel shutdown.
 505
 506           This is only for Iris machines from EuroBraille.
 507
 508           If unused, say N.
 509
 510 config SCHED_OMIT_FRAME_POINTER
 511         def_bool y
 512         prompt "Single-depth WCHAN output"
 513         depends on X86
 514         ---help---
 515           Calculate simpler /proc/<PID>/wchan values. If this option
 516           is disabled then wchan values will recurse back to the
 517           caller function. This provides more accurate wchan values,
 518           at the expense of slightly more scheduling overhead.
 519
 520           If in doubt, say "Y".
 521
 522 menuconfig PARAVIRT_GUEST
 523         bool "Paravirtualized guest support"
 524         ---help---
 525           Say Y here to get to see options related to running Linux under
 526           various hypervisors.  This option alone does not add any kernel code.
 527
 528           If you say N, all options in this submenu will be skipped and disabled.
 529
 530 if PARAVIRT_GUEST
 531
 532 config PARAVIRT_TIME_ACCOUNTING
 533         bool "Paravirtual steal time accounting"
 534         select PARAVIRT
 535         default n
 536         ---help---
 537           Select this option to enable fine granularity task steal time
 538           accounting. Time spent executing other tasks in parallel with
 539           the current vCPU is discounted from the vCPU power. To account for
 540           that, there can be a small performance impact.
 541
 542           If in doubt, say N here.
 543
 544 source "arch/x86/xen/Kconfig"
 545
 546 config KVM_CLOCK
 547         bool "KVM paravirtualized clock"
 548         select PARAVIRT
 549         select PARAVIRT_CLOCK
 550         ---help---
 551           Turning on this option will allow you to run a paravirtualized clock
 552           when running over the KVM hypervisor. Instead of relying on a PIT
 553           (or probably other) emulation by the underlying device model, the host
 554           provides the guest with timing infrastructure such as time of day, and
 555           system time
 556
 557 config KVM_GUEST
 558         bool "KVM Guest support"
 559         select PARAVIRT
 560         ---help---
 561           This option enables various optimizations for running under the KVM
 562           hypervisor.
 563
 564 source "arch/x86/lguest/Kconfig"
 565
 566 config PARAVIRT
 567         bool "Enable paravirtualization code"
 568         ---help---
 569           This changes the kernel so it can modify itself when it is run
 570           under a hypervisor, potentially improving performance significantly
 571           over full virtualization.  However, when run without a hypervisor
 572           the kernel is theoretically slower and slightly larger.
 573
 574 config PARAVIRT_SPINLOCKS
 575         bool "Paravirtualization layer for spinlocks"
 576         depends on PARAVIRT && SMP && EXPERIMENTAL
 577         ---help---
 578           Paravirtualized spinlocks allow a pvops backend to replace the
 579           spinlock implementation with something virtualization-friendly
 580           (for example, block the virtual CPU rather than spinning).
 581
 582           Unfortunately the downside is an up to 5% performance hit on
 583           native kernels, with various workloads.
 584
 585           If you are unsure how to answer this question, answer N.
 586
 587 config PARAVIRT_CLOCK
 588         bool
 589
 590 endif
 591
 592 config PARAVIRT_DEBUG
 593         bool "paravirt-ops debugging"
 594         depends on PARAVIRT && DEBUG_KERNEL
 595         ---help---
 596           Enable to debug paravirt_ops internals.  Specifically, BUG if
 597           a paravirt_op is missing when it is called.
 598
 599 config NO_BOOTMEM
 600         def_bool y
 601
 602 config MEMTEST
 603         bool "Memtest"
 604         ---help---
 605           This option adds a kernel parameter 'memtest', which allows memtest
 606           to be set.
 607                 memtest=0, mean disabled; -- default
 608                 memtest=1, mean do 1 test pattern;
 609                 ...
 610                 memtest=4, mean do 4 test patterns.
 611           If you are unsure how to answer this question, answer N.
 612
 613 config X86_SUMMIT_NUMA
 614         def_bool y
 615         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 616
 617 config X86_CYCLONE_TIMER
 618         def_bool y
 619         depends on X86_32_NON_STANDARD
 620
 621 source "arch/x86/Kconfig.cpu"
 622
 623 config HPET_TIMER
 624         def_bool X86_64
 625         prompt "HPET Timer Support" if X86_32
 626         ---help---
 627           Use the IA-PC HPET (High Precision Event Timer) to manage
 628           time in preference to the PIT and RTC, if a HPET is
 629           present.
 630           HPET is the next generation timer replacing legacy 8254s.
 631           The HPET provides a stable time base on SMP
 632           systems, unlike the TSC, but it is more expensive to access,
 633           as it is off-chip.  You can find the HPET spec at
 634           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 635
 636           You can safely choose Y here.  However, HPET will only be
 637           activated if the platform and the BIOS support this feature.
 638           Otherwise the 8254 will be used for timing services.
 639
 640           Choose N to continue using the legacy 8254 timer.
 641
 642 config HPET_EMULATE_RTC
 643         def_bool y
 644         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 645
 646 config APB_TIMER
 647        def_bool y if MRST
 648        prompt "Langwell APB Timer Support" if X86_MRST
 649        select DW_APB_TIMER
 650        help
 651          APB timer is the replacement for 8254, HPET on X86 MID platforms.
 652          The APBT provides a stable time base on SMP
 653          systems, unlike the TSC, but it is more expensive to access,
 654          as it is off-chip. APB timers are always running regardless of CPU
 655          C states, they are used as per CPU clockevent device when possible.
 656
 657 # Mark as expert because too many people got it wrong.
 658 # The code disables itself when not needed.
 659 config DMI
 660         default y
 661         bool "Enable DMI scanning" if EXPERT
 662         ---help---
 663           Enabled scanning of DMI to identify machine quirks. Say Y
 664           here unless you have verified that your setup is not
 665           affected by entries in the DMI blacklist. Required by PNP
 666           BIOS code.
 667
 668 config GART_IOMMU
 669         bool "GART IOMMU support" if EXPERT
 670         default y
 671         select SWIOTLB
 672         depends on X86_64 && PCI && AMD_NB
 673         ---help---
 674           Support for full DMA access of devices with 32bit memory access only
 675           on systems with more than 3GB. This is usually needed for USB,
 676           sound, many IDE/SATA chipsets and some other devices.
 677           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 678           based hardware IOMMU and a software bounce buffer based IOMMU used
 679           on Intel systems and as fallback.
 680           The code is only active when needed (enough memory and limited
 681           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 682           too.
 683
 684 config CALGARY_IOMMU
 685         bool "IBM Calgary IOMMU support"
 686         select SWIOTLB
 687         depends on X86_64 && PCI && EXPERIMENTAL
 688         ---help---
 689           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 690           systems. Needed to run systems with more than 3GB of memory
 691           properly with 32-bit PCI devices that do not support DAC
 692           (Double Address Cycle). Calgary also supports bus level
 693           isolation, where all DMAs pass through the IOMMU.  This
 694           prevents them from going anywhere except their intended
 695           destination. This catches hard-to-find kernel bugs and
 696           mis-behaving drivers and devices that do not use the DMA-API
 697           properly to set up their DMA buffers.  The IOMMU can be
 698           turned off at boot time with the iommu=off parameter.
 699           Normally the kernel will make the right choice by itself.
 700           If unsure, say Y.
 701
 702 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 703         def_bool y
 704         prompt "Should Calgary be enabled by default?"
 705         depends on CALGARY_IOMMU
 706         ---help---
 707           Should Calgary be enabled by default? if you choose 'y', Calgary
 708           will be used (if it exists). If you choose 'n', Calgary will not be
 709           used even if it exists. If you choose 'n' and would like to use
 710           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 711           If unsure, say Y.
 712
 713 # need this always selected by IOMMU for the VIA workaround
 714 config SWIOTLB
 715         def_bool y if X86_64
 716         ---help---
 717           Support for software bounce buffers used on x86-64 systems
 718           which don't have a hardware IOMMU (e.g. the current generation
 719           of Intel's x86-64 CPUs). Using this PCI devices which can only
 720           access 32-bits of memory can be used on systems with more than
 721           3 GB of memory. If unsure, say Y.
 722
 723 config IOMMU_HELPER
 724         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 725
 726 config MAXSMP
 727         bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 728         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 729         select CPUMASK_OFFSTACK
 730         ---help---
 731           Enable maximum number of CPUS and NUMA Nodes for this architecture.
 732           If unsure, say N.
 733
 734 config NR_CPUS
 735         int "Maximum number of CPUs" if SMP && !MAXSMP
 736         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 737         range 2 512 if SMP && !MAXSMP
 738         default "1" if !SMP
 739         default "4096" if MAXSMP
 740         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 741         default "8" if SMP
 742         ---help---
 743           This allows you to specify the maximum number of CPUs which this
 744           kernel will support.  The maximum supported value is 512 and the
 745           minimum value which makes sense is 2.
 746
 747           This is purely to save memory - each supported CPU adds
 748           approximately eight kilobytes to the kernel image.
 749
 750 config SCHED_SMT
 751         bool "SMT (Hyperthreading) scheduler support"
 752         depends on X86_HT
 753         ---help---
 754           SMT scheduler support improves the CPU scheduler's decision making
 755           when dealing with Intel Pentium 4 chips with HyperThreading at a
 756           cost of slightly increased overhead in some places. If unsure say
 757           N here.
 758
 759 config SCHED_MC
 760         def_bool y
 761         prompt "Multi-core scheduler support"
 762         depends on X86_HT
 763         ---help---
 764           Multi-core scheduler support improves the CPU scheduler's decision
 765           making when dealing with multi-core CPU chips at a cost of slightly
 766           increased overhead in some places. If unsure say N here.
 767
 768 config IRQ_TIME_ACCOUNTING
 769         bool "Fine granularity task level IRQ time accounting"
 770         default n
 771         ---help---
 772           Select this option to enable fine granularity task irq time
 773           accounting. This is done by reading a timestamp on each
 774           transitions between softirq and hardirq state, so there can be a
 775           small performance impact.
 776
 777           If in doubt, say N here.
 778
 779 source "kernel/Kconfig.preempt"
 780
 781 config X86_UP_APIC
 782         bool "Local APIC support on uniprocessors"
 783         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 784         ---help---
 785           A local APIC (Advanced Programmable Interrupt Controller) is an
 786           integrated interrupt controller in the CPU. If you have a single-CPU
 787           system which has a processor with a local APIC, you can say Y here to
 788           enable and use it. If you say Y here even though your machine doesn't
 789           have a local APIC, then the kernel will still run with no slowdown at
 790           all. The local APIC supports CPU-generated self-interrupts (timer,
 791           performance counters), and the NMI watchdog which detects hard
 792           lockups.
 793
 794 config X86_UP_IOAPIC
 795         bool "IO-APIC support on uniprocessors"
 796         depends on X86_UP_APIC
 797         ---help---
 798           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 799           SMP-capable replacement for PC-style interrupt controllers. Most
 800           SMP systems and many recent uniprocessor systems have one.
 801
 802           If you have a single-CPU system with an IO-APIC, you can say Y here
 803           to use it. If you say Y here even though your machine doesn't have
 804           an IO-APIC, then the kernel will still run with no slowdown at all.
 805
 806 config X86_LOCAL_APIC
 807         def_bool y
 808         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 809
 810 config X86_IO_APIC
 811         def_bool y
 812         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
 813
 814 config X86_VISWS_APIC
 815         def_bool y
 816         depends on X86_32 && X86_VISWS
 817
 818 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 819         bool "Reroute for broken boot IRQs"
 820         depends on X86_IO_APIC
 821         ---help---
 822           This option enables a workaround that fixes a source of
 823           spurious interrupts. This is recommended when threaded
 824           interrupt handling is used on systems where the generation of
 825           superfluous "boot interrupts" cannot be disabled.
 826
 827           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 828           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 829           kernel does during interrupt handling). On chipsets where this
 830           boot IRQ generation cannot be disabled, this workaround keeps
 831           the original IRQ line masked so that only the equivalent "boot
 832           IRQ" is delivered to the CPUs. The workaround also tells the
 833           kernel to set up the IRQ handler on the boot IRQ line. In this
 834           way only one interrupt is delivered to the kernel. Otherwise
 835           the spurious second interrupt may cause the kernel to bring
 836           down (vital) interrupt lines.
 837
 838           Only affects "broken" chipsets. Interrupt sharing may be
 839           increased on these systems.
 840
 841 config X86_MCE
 842         bool "Machine Check / overheating reporting"
 843         ---help---
 844           Machine Check support allows the processor to notify the
 845           kernel if it detects a problem (e.g. overheating, data corruption).
 846           The action the kernel takes depends on the severity of the problem,
 847           ranging from warning messages to halting the machine.
 848
 849 config X86_MCE_INTEL
 850         def_bool y
 851         prompt "Intel MCE features"
 852         depends on X86_MCE && X86_LOCAL_APIC
 853         ---help---
 854            Additional support for intel specific MCE features such as
 855            the thermal monitor.
 856
 857 config X86_MCE_AMD
 858         def_bool y
 859         prompt "AMD MCE features"
 860         depends on X86_MCE && X86_LOCAL_APIC
 861         ---help---
 862            Additional support for AMD specific MCE features such as
 863            the DRAM Error Threshold.
 864
 865 config X86_ANCIENT_MCE
 866         bool "Support for old Pentium 5 / WinChip machine checks"
 867         depends on X86_32 && X86_MCE
 868         ---help---
 869           Include support for machine check handling on old Pentium 5 or WinChip
 870           systems. These typically need to be enabled explicitely on the command
 871           line.
 872
 873 config X86_MCE_THRESHOLD
 874         depends on X86_MCE_AMD || X86_MCE_INTEL
 875         def_bool y
 876
 877 config X86_MCE_INJECT
 878         depends on X86_MCE
 879         tristate "Machine check injector support"
 880         ---help---
 881           Provide support for injecting machine checks for testing purposes.
 882           If you don't know what a machine check is and you don't do kernel
 883           QA it is safe to say n.
 884
 885 config X86_THERMAL_VECTOR
 886         def_bool y
 887         depends on X86_MCE_INTEL
 888
 889 config VM86
 890         bool "Enable VM86 support" if EXPERT
 891         default y
 892         depends on X86_32
 893         ---help---
 894           This option is required by programs like DOSEMU to run 16-bit legacy
 895           code on X86 processors. It also may be needed by software like
 896           XFree86 to initialize some video cards via BIOS. Disabling this
 897           option saves about 6k.
 898
 899 config TOSHIBA
 900         tristate "Toshiba Laptop support"
 901         depends on X86_32
 902         ---help---
 903           This adds a driver to safely access the System Management Mode of
 904           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 905           not work on models with a Phoenix BIOS. The System Management Mode
 906           is used to set the BIOS and power saving options on Toshiba portables.
 907
 908           For information on utilities to make use of this driver see the
 909           Toshiba Linux utilities web site at:
 910           <http://www.buzzard.org.uk/toshiba/>.
 911
 912           Say Y if you intend to run this kernel on a Toshiba portable.
 913           Say N otherwise.
 914
 915 config I8K
 916         tristate "Dell laptop support"
 917         select HWMON
 918         ---help---
 919           This adds a driver to safely access the System Management Mode
 920           of the CPU on the Dell Inspiron 8000. The System Management Mode
 921           is used to read cpu temperature and cooling fan status and to
 922           control the fans on the I8K portables.
 923
 924           This driver has been tested only on the Inspiron 8000 but it may
 925           also work with other Dell laptops. You can force loading on other
 926           models by passing the parameter `force=1' to the module. Use at
 927           your own risk.
 928
 929           For information on utilities to make use of this driver see the
 930           I8K Linux utilities web site at:
 931           <http://people.debian.org/~dz/i8k/>
 932
 933           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 934           Say N otherwise.
 935
 936 config X86_REBOOTFIXUPS
 937         bool "Enable X86 board specific fixups for reboot"
 938         depends on X86_32
 939         ---help---
 940           This enables chipset and/or board specific fixups to be done
 941           in order to get reboot to work correctly. This is only needed on
 942           some combinations of hardware and BIOS. The symptom, for which
 943           this config is intended, is when reboot ends with a stalled/hung
 944           system.
 945
 946           Currently, the only fixup is for the Geode machines using
 947           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 948
 949           Say Y if you want to enable the fixup. Currently, it's safe to
 950           enable this option even if you don't need it.
 951           Say N otherwise.
 952
 953 config MICROCODE
 954         tristate "/dev/cpu/microcode - microcode support"
 955         select FW_LOADER
 956         ---help---
 957           If you say Y here, you will be able to update the microcode on
 958           certain Intel and AMD processors. The Intel support is for the
 959           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 960           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 961           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 962           You will obviously need the actual microcode binary data itself
 963           which is not shipped with the Linux kernel.
 964
 965           This option selects the general module only, you need to select
 966           at least one vendor specific module as well.
 967
 968           To compile this driver as a module, choose M here: the
 969           module will be called microcode.
 970
 971 config MICROCODE_INTEL
 972         bool "Intel microcode patch loading support"
 973         depends on MICROCODE
 974         default MICROCODE
 975         select FW_LOADER
 976         ---help---
 977           This options enables microcode patch loading support for Intel
 978           processors.
 979
 980           For latest news and information on obtaining all the required
 981           Intel ingredients for this driver, check:
 982           <http://www.urbanmyth.org/microcode/>.
 983
 984 config MICROCODE_AMD
 985         bool "AMD microcode patch loading support"
 986         depends on MICROCODE
 987         select FW_LOADER
 988         ---help---
 989           If you select this option, microcode patch loading support for AMD
 990           processors will be enabled.
 991
 992 config MICROCODE_OLD_INTERFACE
 993         def_bool y
 994         depends on MICROCODE
 995
 996 config X86_MSR
 997         tristate "/dev/cpu/*/msr - Model-specific register support"
 998         ---help---
 999           This device gives privileged processes access to the x86
1000           Model-Specific Registers (MSRs).  It is a character device with
1001           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1002           MSR accesses are directed to a specific CPU on multi-processor
1003           systems.
1004
1005 config X86_CPUID
1006         tristate "/dev/cpu/*/cpuid - CPU information support"
1007         ---help---
1008           This device gives processes access to the x86 CPUID instruction to
1009           be executed on a specific processor.  It is a character device
1010           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1011           /dev/cpu/31/cpuid.
1012
1013 choice
1014         prompt "High Memory Support"
1015         default HIGHMEM64G if X86_NUMAQ
1016         default HIGHMEM4G
1017         depends on X86_32
1018
1019 config NOHIGHMEM
1020         bool "off"
1021         depends on !X86_NUMAQ
1022         ---help---
1023           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1024           However, the address space of 32-bit x86 processors is only 4
1025           Gigabytes large. That means that, if you have a large amount of
1026           physical memory, not all of it can be "permanently mapped" by the
1027           kernel. The physical memory that's not permanently mapped is called
1028           "high memory".
1029
1030           If you are compiling a kernel which will never run on a machine with
1031           more than 1 Gigabyte total physical RAM, answer "off" here (default
1032           choice and suitable for most users). This will result in a "3GB/1GB"
1033           split: 3GB are mapped so that each process sees a 3GB virtual memory
1034           space and the remaining part of the 4GB virtual memory space is used
1035           by the kernel to permanently map as much physical memory as
1036           possible.
1037
1038           If the machine has between 1 and 4 Gigabytes physical RAM, then
1039           answer "4GB" here.
1040
1041           If more than 4 Gigabytes is used then answer "64GB" here. This
1042           selection turns Intel PAE (Physical Address Extension) mode on.
1043           PAE implements 3-level paging on IA32 processors. PAE is fully
1044           supported by Linux, PAE mode is implemented on all recent Intel
1045           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1046           then the kernel will not boot on CPUs that don't support PAE!
1047
1048           The actual amount of total physical memory will either be
1049           auto detected or can be forced by using a kernel command line option
1050           such as "mem=256M". (Try "man bootparam" or see the documentation of
1051           your boot loader (lilo or loadlin) about how to pass options to the
1052           kernel at boot time.)
1053
1054           If unsure, say "off".
1055
1056 config HIGHMEM4G
1057         bool "4GB"
1058         depends on !X86_NUMAQ
1059         ---help---
1060           Select this if you have a 32-bit processor and between 1 and 4
1061           gigabytes of physical RAM.
1062
1063 config HIGHMEM64G
1064         bool "64GB"
1065         depends on !M386 && !M486
1066         select X86_PAE
1067         ---help---
1068           Select this if you have a 32-bit processor and more than 4
1069           gigabytes of physical RAM.
1070
1071 endchoice
1072
1073 choice
1074         depends on EXPERIMENTAL
1075         prompt "Memory split" if EXPERT
1076         default VMSPLIT_3G
1077         depends on X86_32
1078         ---help---
1079           Select the desired split between kernel and user memory.
1080
1081           If the address range available to the kernel is less than the
1082           physical memory installed, the remaining memory will be available
1083           as "high memory". Accessing high memory is a little more costly
1084           than low memory, as it needs to be mapped into the kernel first.
1085           Note that increasing the kernel address space limits the range
1086           available to user programs, making the address space there
1087           tighter.  Selecting anything other than the default 3G/1G split
1088           will also likely make your kernel incompatible with binary-only
1089           kernel modules.
1090
1091           If you are not absolutely sure what you are doing, leave this
1092           option alone!
1093
1094         config VMSPLIT_3G
1095                 bool "3G/1G user/kernel split"
1096         config VMSPLIT_3G_OPT
1097                 depends on !X86_PAE
1098                 bool "3G/1G user/kernel split (for full 1G low memory)"
1099         config VMSPLIT_2G
1100                 bool "2G/2G user/kernel split"
1101         config VMSPLIT_2G_OPT
1102                 depends on !X86_PAE
1103                 bool "2G/2G user/kernel split (for full 2G low memory)"
1104         config VMSPLIT_1G
1105                 bool "1G/3G user/kernel split"
1106 endchoice
1107
1108 config PAGE_OFFSET
1109         hex
1110         default 0xB0000000 if VMSPLIT_3G_OPT
1111         default 0x80000000 if VMSPLIT_2G
1112         default 0x78000000 if VMSPLIT_2G_OPT
1113         default 0x40000000 if VMSPLIT_1G
1114         default 0xC0000000
1115         depends on X86_32
1116
1117 config HIGHMEM
1118         def_bool y
1119         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1120
1121 config X86_PAE
1122         bool "PAE (Physical Address Extension) Support"
1123         depends on X86_32 && !HIGHMEM4G
1124         ---help---
1125           PAE is required for NX support, and furthermore enables
1126           larger swapspace support for non-overcommit purposes. It
1127           has the cost of more pagetable lookup overhead, and also
1128           consumes more pagetable space per process.
1129
1130 config ARCH_PHYS_ADDR_T_64BIT
1131         def_bool X86_64 || X86_PAE
1132
1133 config ARCH_DMA_ADDR_T_64BIT
1134         def_bool X86_64 || HIGHMEM64G
1135
1136 config DIRECT_GBPAGES
1137         bool "Enable 1GB pages for kernel pagetables" if EXPERT
1138         default y
1139         depends on X86_64
1140         ---help---
1141           Allow the kernel linear mapping to use 1GB pages on CPUs that
1142           support it. This can improve the kernel's performance a tiny bit by
1143           reducing TLB pressure. If in doubt, say "Y".
1144
1145 # Common NUMA Features
1146 config NUMA
1147         bool "Numa Memory Allocation and Scheduler Support"
1148         depends on SMP
1149         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1150         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1151         ---help---
1152           Enable NUMA (Non Uniform Memory Access) support.
1153
1154           The kernel will try to allocate memory used by a CPU on the
1155           local memory controller of the CPU and add some more
1156           NUMA awareness to the kernel.
1157
1158           For 64-bit this is recommended if the system is Intel Core i7
1159           (or later), AMD Opteron, or EM64T NUMA.
1160
1161           For 32-bit this is only needed on (rare) 32-bit-only platforms
1162           that support NUMA topologies, such as NUMAQ / Summit, or if you
1163           boot a 32-bit kernel on a 64-bit NUMA platform.
1164
1165           Otherwise, you should say N.
1166
1167 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1168         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1169
1170 config AMD_NUMA
1171         def_bool y
1172         prompt "Old style AMD Opteron NUMA detection"
1173         depends on X86_64 && NUMA && PCI
1174         ---help---
1175           Enable AMD NUMA node topology detection.  You should say Y here if
1176           you have a multi processor AMD system. This uses an old method to
1177           read the NUMA configuration directly from the builtin Northbridge
1178           of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1179           which also takes priority if both are compiled in.
1180
1181 config X86_64_ACPI_NUMA
1182         def_bool y
1183         prompt "ACPI NUMA detection"
1184         depends on X86_64 && NUMA && ACPI && PCI
1185         select ACPI_NUMA
1186         ---help---
1187           Enable ACPI SRAT based node topology detection.
1188
1189 # Some NUMA nodes have memory ranges that span
1190 # other nodes.  Even though a pfn is valid and
1191 # between a node's start and end pfns, it may not
1192 # reside on that node.  See memmap_init_zone()
1193 # for details.
1194 config NODES_SPAN_OTHER_NODES
1195         def_bool y
1196         depends on X86_64_ACPI_NUMA
1197
1198 config NUMA_EMU
1199         bool "NUMA emulation"
1200         depends on NUMA
1201         ---help---
1202           Enable NUMA emulation. A flat machine will be split
1203           into virtual nodes when booted with "numa=fake=N", where N is the
1204           number of nodes. This is only useful for debugging.
1205
1206 config NODES_SHIFT
1207         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1208         range 1 10
1209         default "10" if MAXSMP
1210         default "6" if X86_64
1211         default "4" if X86_NUMAQ
1212         default "3"
1213         depends on NEED_MULTIPLE_NODES
1214         ---help---
1215           Specify the maximum number of NUMA Nodes available on the target
1216           system.  Increases memory reserved to accommodate various tables.
1217
1218 config HAVE_ARCH_BOOTMEM
1219         def_bool y
1220         depends on X86_32 && NUMA
1221
1222 config HAVE_ARCH_ALLOC_REMAP
1223         def_bool y
1224         depends on X86_32 && NUMA
1225
1226 config ARCH_HAVE_MEMORY_PRESENT
1227         def_bool y
1228         depends on X86_32 && DISCONTIGMEM
1229
1230 config NEED_NODE_MEMMAP_SIZE
1231         def_bool y
1232         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1233
1234 config ARCH_FLATMEM_ENABLE
1235         def_bool y
1236         depends on X86_32 && !NUMA
1237
1238 config ARCH_DISCONTIGMEM_ENABLE
1239         def_bool y
1240         depends on NUMA && X86_32
1241
1242 config ARCH_DISCONTIGMEM_DEFAULT
1243         def_bool y
1244         depends on NUMA && X86_32
1245
1246 config ARCH_SPARSEMEM_ENABLE
1247         def_bool y
1248         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1249         select SPARSEMEM_STATIC if X86_32
1250         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1251
1252 config ARCH_SPARSEMEM_DEFAULT
1253         def_bool y
1254         depends on X86_64
1255
1256 config ARCH_SELECT_MEMORY_MODEL
1257         def_bool y
1258         depends on ARCH_SPARSEMEM_ENABLE
1259
1260 config ARCH_MEMORY_PROBE
1261         def_bool X86_64
1262         depends on MEMORY_HOTPLUG
1263
1264 config ARCH_PROC_KCORE_TEXT
1265         def_bool y
1266         depends on X86_64 && PROC_KCORE
1267
1268 config ILLEGAL_POINTER_VALUE
1269        hex
1270        default 0 if X86_32
1271        default 0xdead000000000000 if X86_64
1272
1273 source "mm/Kconfig"
1274
1275 config HIGHPTE
1276         bool "Allocate 3rd-level pagetables from highmem"
1277         depends on HIGHMEM
1278         ---help---
1279           The VM uses one page table entry for each page of physical memory.
1280           For systems with a lot of RAM, this can be wasteful of precious
1281           low memory.  Setting this option will put user-space page table
1282           entries in high memory.
1283
1284 config X86_CHECK_BIOS_CORRUPTION
1285         bool "Check for low memory corruption"
1286         ---help---
1287           Periodically check for memory corruption in low memory, which
1288           is suspected to be caused by BIOS.  Even when enabled in the
1289           configuration, it is disabled at runtime.  Enable it by
1290           setting "memory_corruption_check=1" on the kernel command
1291           line.  By default it scans the low 64k of memory every 60
1292           seconds; see the memory_corruption_check_size and
1293           memory_corruption_check_period parameters in
1294           Documentation/kernel-parameters.txt to adjust this.
1295
1296           When enabled with the default parameters, this option has
1297           almost no overhead, as it reserves a relatively small amount
1298           of memory and scans it infrequently.  It both detects corruption
1299           and prevents it from affecting the running system.
1300
1301           It is, however, intended as a diagnostic tool; if repeatable
1302           BIOS-originated corruption always affects the same memory,
1303           you can use memmap= to prevent the kernel from using that
1304           memory.
1305
1306 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1307         bool "Set the default setting of memory_corruption_check"
1308         depends on X86_CHECK_BIOS_CORRUPTION
1309         default y
1310         ---help---
1311           Set whether the default state of memory_corruption_check is
1312           on or off.
1313
1314 config X86_RESERVE_LOW
1315         int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1316         default 64
1317         range 4 640
1318         ---help---
1319           Specify the amount of low memory to reserve for the BIOS.
1320
1321           The first page contains BIOS data structures that the kernel
1322           must not use, so that page must always be reserved.
1323
1324           By default we reserve the first 64K of physical RAM, as a
1325           number of BIOSes are known to corrupt that memory range
1326           during events such as suspend/resume or monitor cable
1327           insertion, so it must not be used by the kernel.
1328
1329           You can set this to 4 if you are absolutely sure that you
1330           trust the BIOS to get all its memory reservations and usages
1331           right.  If you know your BIOS have problems beyond the
1332           default 64K area, you can set this to 640 to avoid using the
1333           entire low memory range.
1334
1335           If you have doubts about the BIOS (e.g. suspend/resume does
1336           not work or there's kernel crashes after certain hardware
1337           hotplug events) then you might want to enable
1338           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1339           typical corruption patterns.
1340
1341           Leave this to the default value of 64 if you are unsure.
1342
1343 config MATH_EMULATION
1344         bool
1345         prompt "Math emulation" if X86_32
1346         ---help---
1347           Linux can emulate a math coprocessor (used for floating point
1348           operations) if you don't have one. 486DX and Pentium processors have
1349           a math coprocessor built in, 486SX and 386 do not, unless you added
1350           a 487DX or 387, respectively. (The messages during boot time can
1351           give you some hints here ["man dmesg"].) Everyone needs either a
1352           coprocessor or this emulation.
1353
1354           If you don't have a math coprocessor, you need to say Y here; if you
1355           say Y here even though you have a coprocessor, the coprocessor will
1356           be used nevertheless. (This behavior can be changed with the kernel
1357           command line option "no387", which comes handy if your coprocessor
1358           is broken. Try "man bootparam" or see the documentation of your boot
1359           loader (lilo or loadlin) about how to pass options to the kernel at
1360           boot time.) This means that it is a good idea to say Y here if you
1361           intend to use this kernel on different machines.
1362
1363           More information about the internals of the Linux math coprocessor
1364           emulation can be found in <file:arch/x86/math-emu/README>.
1365
1366           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1367           kernel, it won't hurt.
1368
1369 config MTRR
1370         def_bool y
1371         prompt "MTRR (Memory Type Range Register) support" if EXPERT
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         def_bool y
1437         prompt "x86 PAT support" if EXPERT
1438         depends on MTRR
1439         ---help---
1440           Use PAT attributes to setup page level cache control.
1441
1442           PATs are the modern equivalents of MTRRs and are much more
1443           flexible than MTRRs.
1444
1445           Say N here if you see bootup problems (boot crash, boot hang,
1446           spontaneous reboots) or a non-working video driver.
1447
1448           If unsure, say Y.
1449
1450 config ARCH_USES_PG_UNCACHED
1451         def_bool y
1452         depends on X86_PAT
1453
1454 config EFI
1455         bool "EFI runtime service support"
1456         depends on ACPI
1457         ---help---
1458           This enables the kernel to use EFI runtime services that are
1459           available (such as the EFI variable services).
1460
1461           This option is only useful on systems that have EFI firmware.
1462           In addition, you should use the latest ELILO loader available
1463           at <http://elilo.sourceforge.net> in order to take advantage
1464           of EFI runtime services. However, even with this option, the
1465           resultant kernel should continue to boot on existing non-EFI
1466           platforms.
1467
1468 config SECCOMP
1469         def_bool y
1470         prompt "Enable seccomp to safely compute untrusted bytecode"
1471         ---help---
1472           This kernel feature is useful for number crunching applications
1473           that may need to compute untrusted bytecode during their
1474           execution. By using pipes or other transports made available to
1475           the process as file descriptors supporting the read/write
1476           syscalls, it's possible to isolate those applications in
1477           their own address space using seccomp. Once seccomp is
1478           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1479           and the task is only allowed to execute a few safe syscalls
1480           defined by each seccomp mode.
1481
1482           If unsure, say Y. Only embedded should say N here.
1483
1484 config CC_STACKPROTECTOR
1485         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1486         ---help---
1487           This option turns on the -fstack-protector GCC feature. This
1488           feature puts, at the beginning of functions, a canary value on
1489           the stack just before the return address, and validates
1490           the value just before actually returning.  Stack based buffer
1491           overflows (that need to overwrite this return address) now also
1492           overwrite the canary, which gets detected and the attack is then
1493           neutralized via a kernel panic.
1494
1495           This feature requires gcc version 4.2 or above, or a distribution
1496           gcc with the feature backported. Older versions are automatically
1497           detected and for those versions, this configuration option is
1498           ignored. (and a warning is printed during bootup)
1499
1500 source kernel/Kconfig.hz
1501
1502 config KEXEC
1503         bool "kexec system call"
1504         ---help---
1505           kexec is a system call that implements the ability to shutdown your
1506           current kernel, and to start another kernel.  It is like a reboot
1507           but it is independent of the system firmware.   And like a reboot
1508           you can start any kernel with it, not just Linux.
1509
1510           The name comes from the similarity to the exec system call.
1511
1512           It is an ongoing process to be certain the hardware in a machine
1513           is properly shutdown, so do not be surprised if this code does not
1514           initially work for you.  It may help to enable device hotplugging
1515           support.  As of this writing the exact hardware interface is
1516           strongly in flux, so no good recommendation can be made.
1517
1518 config CRASH_DUMP
1519         bool "kernel crash dumps"
1520         depends on X86_64 || (X86_32 && HIGHMEM)
1521         ---help---
1522           Generate crash dump after being started by kexec.
1523           This should be normally only set in special crash dump kernels
1524           which are loaded in the main kernel with kexec-tools into
1525           a specially reserved region and then later executed after
1526           a crash by kdump/kexec. The crash dump kernel must be compiled
1527           to a memory address not used by the main kernel or BIOS using
1528           PHYSICAL_START, or it must be built as a relocatable image
1529           (CONFIG_RELOCATABLE=y).
1530           For more details see Documentation/kdump/kdump.txt
1531
1532 config KEXEC_JUMP
1533         bool "kexec jump (EXPERIMENTAL)"
1534         depends on EXPERIMENTAL
1535         depends on KEXEC && HIBERNATION
1536         ---help---
1537           Jump between original kernel and kexeced kernel and invoke
1538           code in physical address mode via KEXEC
1539
1540 config PHYSICAL_START
1541         hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1542         default "0x1000000"
1543         ---help---
1544           This gives the physical address where the kernel is loaded.
1545
1546           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1547           bzImage will decompress itself to above physical address and
1548           run from there. Otherwise, bzImage will run from the address where
1549           it has been loaded by the boot loader and will ignore above physical
1550           address.
1551
1552           In normal kdump cases one does not have to set/change this option
1553           as now bzImage can be compiled as a completely relocatable image
1554           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1555           address. This option is mainly useful for the folks who don't want
1556           to use a bzImage for capturing the crash dump and want to use a
1557           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1558           to be specifically compiled to run from a specific memory area
1559           (normally a reserved region) and this option comes handy.
1560
1561           So if you are using bzImage for capturing the crash dump,
1562           leave the value here unchanged to 0x1000000 and set
1563           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1564           for capturing the crash dump change this value to start of
1565           the reserved region.  In other words, it can be set based on
1566           the "X" value as specified in the "crashkernel=YM@XM"
1567           command line boot parameter passed to the panic-ed
1568           kernel. Please take a look at Documentation/kdump/kdump.txt
1569           for more details about crash dumps.
1570
1571           Usage of bzImage for capturing the crash dump is recommended as
1572           one does not have to build two kernels. Same kernel can be used
1573           as production kernel and capture kernel. Above option should have
1574           gone away after relocatable bzImage support is introduced. But it
1575           is present because there are users out there who continue to use
1576           vmlinux for dump capture. This option should go away down the
1577           line.
1578
1579           Don't change this unless you know what you are doing.
1580
1581 config RELOCATABLE
1582         bool "Build a relocatable kernel"
1583         default y
1584         ---help---
1585           This builds a kernel image that retains relocation information
1586           so it can be loaded someplace besides the default 1MB.
1587           The relocations tend to make the kernel binary about 10% larger,
1588           but are discarded at runtime.
1589
1590           One use is for the kexec on panic case where the recovery kernel
1591           must live at a different physical address than the primary
1592           kernel.
1593
1594           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1595           it has been loaded at and the compile time physical address
1596           (CONFIG_PHYSICAL_START) is ignored.
1597
1598 # Relocation on x86-32 needs some additional build support
1599 config X86_NEED_RELOCS
1600         def_bool y
1601         depends on X86_32 && RELOCATABLE
1602
1603 config PHYSICAL_ALIGN
1604         hex "Alignment value to which kernel should be aligned" if X86_32
1605         default "0x1000000"
1606         range 0x2000 0x1000000
1607         ---help---
1608           This value puts the alignment restrictions on physical address
1609           where kernel is loaded and run from. Kernel is compiled for an
1610           address which meets above alignment restriction.
1611
1612           If bootloader loads the kernel at a non-aligned address and
1613           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1614           address aligned to above value and run from there.
1615
1616           If bootloader loads the kernel at a non-aligned address and
1617           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1618           load address and decompress itself to the address it has been
1619           compiled for and run from there. The address for which kernel is
1620           compiled already meets above alignment restrictions. Hence the
1621           end result is that kernel runs from a physical address meeting
1622           above alignment restrictions.
1623
1624           Don't change this unless you know what you are doing.
1625
1626 config HOTPLUG_CPU
1627         bool "Support for hot-pluggable CPUs"
1628         depends on SMP && HOTPLUG
1629         ---help---
1630           Say Y here to allow turning CPUs off and on. CPUs can be
1631           controlled through /sys/devices/system/cpu.
1632           ( Note: power management support will enable this option
1633             automatically on SMP systems. )
1634           Say N if you want to disable CPU hotplug.
1635
1636 config COMPAT_VDSO
1637         def_bool y
1638         prompt "Compat VDSO support"
1639         depends on X86_32 || IA32_EMULATION
1640         ---help---
1641           Map the 32-bit VDSO to the predictable old-style address too.
1642
1643           Say N here if you are running a sufficiently recent glibc
1644           version (2.3.3 or later), to remove the high-mapped
1645           VDSO mapping and to exclusively use the randomized VDSO.
1646
1647           If unsure, say Y.
1648
1649 config CMDLINE_BOOL
1650         bool "Built-in kernel command line"
1651         ---help---
1652           Allow for specifying boot arguments to the kernel at
1653           build time.  On some systems (e.g. embedded ones), it is
1654           necessary or convenient to provide some or all of the
1655           kernel boot arguments with the kernel itself (that is,
1656           to not rely on the boot loader to provide them.)
1657
1658           To compile command line arguments into the kernel,
1659           set this option to 'Y', then fill in the
1660           the boot arguments in CONFIG_CMDLINE.
1661
1662           Systems with fully functional boot loaders (i.e. non-embedded)
1663           should leave this option set to 'N'.
1664
1665 config CMDLINE
1666         string "Built-in kernel command string"
1667         depends on CMDLINE_BOOL
1668         default ""
1669         ---help---
1670           Enter arguments here that should be compiled into the kernel
1671           image and used at boot time.  If the boot loader provides a
1672           command line at boot time, it is appended to this string to
1673           form the full kernel command line, when the system boots.
1674
1675           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1676           change this behavior.
1677
1678           In most cases, the command line (whether built-in or provided
1679           by the boot loader) should specify the device for the root
1680           file system.
1681
1682 config CMDLINE_OVERRIDE
1683         bool "Built-in command line overrides boot loader arguments"
1684         depends on CMDLINE_BOOL
1685         ---help---
1686           Set this option to 'Y' to have the kernel ignore the boot loader
1687           command line, and use ONLY the built-in command line.
1688
1689           This is used to work around broken boot loaders.  This should
1690           be set to 'N' under normal conditions.
1691
1692 endmenu
1693
1694 config ARCH_ENABLE_MEMORY_HOTPLUG
1695         def_bool y
1696         depends on X86_64 || (X86_32 && HIGHMEM)
1697
1698 config ARCH_ENABLE_MEMORY_HOTREMOVE
1699         def_bool y
1700         depends on MEMORY_HOTPLUG
1701
1702 config USE_PERCPU_NUMA_NODE_ID
1703         def_bool y
1704         depends on NUMA
1705
1706 menu "Power management and ACPI options"
1707
1708 config ARCH_HIBERNATION_HEADER
1709         def_bool y
1710         depends on X86_64 && HIBERNATION
1711
1712 source "kernel/power/Kconfig"
1713
1714 source "drivers/acpi/Kconfig"
1715
1716 source "drivers/sfi/Kconfig"
1717
1718 config X86_APM_BOOT
1719         def_bool y
1720         depends on APM || APM_MODULE
1721
1722 menuconfig APM
1723         tristate "APM (Advanced Power Management) BIOS support"
1724         depends on X86_32 && PM_SLEEP
1725         ---help---
1726           APM is a BIOS specification for saving power using several different
1727           techniques. This is mostly useful for battery powered laptops with
1728           APM compliant BIOSes. If you say Y here, the system time will be
1729           reset after a RESUME operation, the /proc/apm device will provide
1730           battery status information, and user-space programs will receive
1731           notification of APM "events" (e.g. battery status change).
1732
1733           If you select "Y" here, you can disable actual use of the APM
1734           BIOS by passing the "apm=off" option to the kernel at boot time.
1735
1736           Note that the APM support is almost completely disabled for
1737           machines with more than one CPU.
1738
1739           In order to use APM, you will need supporting software. For location
1740           and more information, read <file:Documentation/power/apm-acpi.txt>
1741           and the Battery Powered Linux mini-HOWTO, available from
1742           <http://www.tldp.org/docs.html#howto>.
1743
1744           This driver does not spin down disk drives (see the hdparm(8)
1745           manpage ("man 8 hdparm") for that), and it doesn't turn off
1746           VESA-compliant "green" monitors.
1747
1748           This driver does not support the TI 4000M TravelMate and the ACER
1749           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1750           desktop machines also don't have compliant BIOSes, and this driver
1751           may cause those machines to panic during the boot phase.
1752
1753           Generally, if you don't have a battery in your machine, there isn't
1754           much point in using this driver and you should say N. If you get
1755           random kernel OOPSes or reboots that don't seem to be related to
1756           anything, try disabling/enabling this option (or disabling/enabling
1757           APM in your BIOS).
1758
1759           Some other things you should try when experiencing seemingly random,
1760           "weird" problems:
1761
1762           1) make sure that you have enough swap space and that it is
1763           enabled.
1764           2) pass the "no-hlt" option to the kernel
1765           3) switch on floating point emulation in the kernel and pass
1766           the "no387" option to the kernel
1767           4) pass the "floppy=nodma" option to the kernel
1768           5) pass the "mem=4M" option to the kernel (thereby disabling
1769           all but the first 4 MB of RAM)
1770           6) make sure that the CPU is not over clocked.
1771           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1772           8) disable the cache from your BIOS settings
1773           9) install a fan for the video card or exchange video RAM
1774           10) install a better fan for the CPU
1775           11) exchange RAM chips
1776           12) exchange the motherboard.
1777
1778           To compile this driver as a module, choose M here: the
1779           module will be called apm.
1780
1781 if APM
1782
1783 config APM_IGNORE_USER_SUSPEND
1784         bool "Ignore USER SUSPEND"
1785         ---help---
1786           This option will ignore USER SUSPEND requests. On machines with a
1787           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1788           series notebooks, it is necessary to say Y because of a BIOS bug.
1789
1790 config APM_DO_ENABLE
1791         bool "Enable PM at boot time"
1792         ---help---
1793           Enable APM features at boot time. From page 36 of the APM BIOS
1794           specification: "When disabled, the APM BIOS does not automatically
1795           power manage devices, enter the Standby State, enter the Suspend
1796           State, or take power saving steps in response to CPU Idle calls."
1797           This driver will make CPU Idle calls when Linux is idle (unless this
1798           feature is turned off -- see "Do CPU IDLE calls", below). This
1799           should always save battery power, but more complicated APM features
1800           will be dependent on your BIOS implementation. You may need to turn
1801           this option off if your computer hangs at boot time when using APM
1802           support, or if it beeps continuously instead of suspending. Turn
1803           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1804           T400CDT. This is off by default since most machines do fine without
1805           this feature.
1806
1807 config APM_CPU_IDLE
1808         bool "Make CPU Idle calls when idle"
1809         ---help---
1810           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1811           On some machines, this can activate improved power savings, such as
1812           a slowed CPU clock rate, when the machine is idle. These idle calls
1813           are made after the idle loop has run for some length of time (e.g.,
1814           333 mS). On some machines, this will cause a hang at boot time or
1815           whenever the CPU becomes idle. (On machines with more than one CPU,
1816           this option does nothing.)
1817
1818 config APM_DISPLAY_BLANK
1819         bool "Enable console blanking using APM"
1820         ---help---
1821           Enable console blanking using the APM. Some laptops can use this to
1822           turn off the LCD backlight when the screen blanker of the Linux
1823           virtual console blanks the screen. Note that this is only used by
1824           the virtual console screen blanker, and won't turn off the backlight
1825           when using the X Window system. This also doesn't have anything to
1826           do with your VESA-compliant power-saving monitor. Further, this
1827           option doesn't work for all laptops -- it might not turn off your
1828           backlight at all, or it might print a lot of errors to the console,
1829           especially if you are using gpm.
1830
1831 config APM_ALLOW_INTS
1832         bool "Allow interrupts during APM BIOS calls"
1833         ---help---
1834           Normally we disable external interrupts while we are making calls to
1835           the APM BIOS as a measure to lessen the effects of a badly behaving
1836           BIOS implementation.  The BIOS should reenable interrupts if it
1837           needs to.  Unfortunately, some BIOSes do not -- especially those in
1838           many of the newer IBM Thinkpads.  If you experience hangs when you
1839           suspend, try setting this to Y.  Otherwise, say N.
1840
1841 endif # APM
1842
1843 source "drivers/cpufreq/Kconfig"
1844
1845 source "drivers/cpuidle/Kconfig"
1846
1847 source "drivers/idle/Kconfig"
1848
1849 endmenu
1850
1851
1852 menu "Bus options (PCI etc.)"
1853
1854 config PCI
1855         bool "PCI support"
1856         default y
1857         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1858         ---help---
1859           Find out whether you have a PCI motherboard. PCI is the name of a
1860           bus system, i.e. the way the CPU talks to the other stuff inside
1861           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1862           VESA. If you have PCI, say Y, otherwise N.
1863
1864 choice
1865         prompt "PCI access mode"
1866         depends on X86_32 && PCI
1867         default PCI_GOANY
1868         ---help---
1869           On PCI systems, the BIOS can be used to detect the PCI devices and
1870           determine their configuration. However, some old PCI motherboards
1871           have BIOS bugs and may crash if this is done. Also, some embedded
1872           PCI-based systems don't have any BIOS at all. Linux can also try to
1873           detect the PCI hardware directly without using the BIOS.
1874
1875           With this option, you can specify how Linux should detect the
1876           PCI devices. If you choose "BIOS", the BIOS will be used,
1877           if you choose "Direct", the BIOS won't be used, and if you
1878           choose "MMConfig", then PCI Express MMCONFIG will be used.
1879           If you choose "Any", the kernel will try MMCONFIG, then the
1880           direct access method and falls back to the BIOS if that doesn't
1881           work. If unsure, go with the default, which is "Any".
1882
1883 config PCI_GOBIOS
1884         bool "BIOS"
1885
1886 config PCI_GOMMCONFIG
1887         bool "MMConfig"
1888
1889 config PCI_GODIRECT
1890         bool "Direct"
1891
1892 config PCI_GOOLPC
1893         bool "OLPC XO-1"
1894         depends on OLPC
1895
1896 config PCI_GOANY
1897         bool "Any"
1898
1899 endchoice
1900
1901 config PCI_BIOS
1902         def_bool y
1903         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1904
1905 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1906 config PCI_DIRECT
1907         def_bool y
1908         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1909
1910 config PCI_MMCONFIG
1911         def_bool y
1912         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1913
1914 config PCI_OLPC
1915         def_bool y
1916         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1917
1918 config PCI_XEN
1919         def_bool y
1920         depends on PCI && XEN
1921         select SWIOTLB_XEN
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 PCI_CNB20LE_QUIRK
1932         bool "Read CNB20LE Host Bridge Windows" if EXPERT
1933         default n
1934         depends on PCI && EXPERIMENTAL
1935         help
1936           Read the PCI windows out of the CNB20LE host bridge. This allows
1937           PCI hotplug to work on systems with the CNB20LE chipset which do
1938           not have ACPI.
1939
1940           There's no public spec for this chipset, and this functionality
1941           is known to be incomplete.
1942
1943           You should say N unless you know you need this.
1944
1945 source "drivers/pci/pcie/Kconfig"
1946
1947 source "drivers/pci/Kconfig"
1948
1949 # x86_64 have no ISA slots, but can have ISA-style DMA.
1950 config ISA_DMA_API
1951         bool "ISA-style DMA support" if (X86_64 && EXPERT)
1952         default y
1953         help
1954           Enables ISA-style DMA support for devices requiring such controllers.
1955           If unsure, say Y.
1956
1957 if X86_32
1958
1959 config ISA
1960         bool "ISA support"
1961         ---help---
1962           Find out whether you have ISA slots on your motherboard.  ISA is the
1963           name of a bus system, i.e. the way the CPU talks to the other stuff
1964           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1965           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1966           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1967
1968 config EISA
1969         bool "EISA support"
1970         depends on ISA
1971         ---help---
1972           The Extended Industry Standard Architecture (EISA) bus was
1973           developed as an open alternative to the IBM MicroChannel bus.
1974
1975           The EISA bus provided some of the features of the IBM MicroChannel
1976           bus while maintaining backward compatibility with cards made for
1977           the older ISA bus.  The EISA bus saw limited use between 1988 and
1978           1995 when it was made obsolete by the PCI bus.
1979
1980           Say Y here if you are building a kernel for an EISA-based machine.
1981
1982           Otherwise, say N.
1983
1984 source "drivers/eisa/Kconfig"
1985
1986 config MCA
1987         bool "MCA support"
1988         ---help---
1989           MicroChannel Architecture is found in some IBM PS/2 machines and
1990           laptops.  It is a bus system similar to PCI or ISA. See
1991           <file:Documentation/mca.txt> (and especially the web page given
1992           there) before attempting to build an MCA bus kernel.
1993
1994 source "drivers/mca/Kconfig"
1995
1996 config SCx200
1997         tristate "NatSemi SCx200 support"
1998         ---help---
1999           This provides basic support for National Semiconductor's
2000           (now AMD's) Geode processors.  The driver probes for the
2001           PCI-IDs of several on-chip devices, so its a good dependency
2002           for other scx200_* drivers.
2003
2004           If compiled as a module, the driver is named scx200.
2005
2006 config SCx200HR_TIMER
2007         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2008         depends on SCx200
2009         default y
2010         ---help---
2011           This driver provides a clocksource built upon the on-chip
2012           27MHz high-resolution timer.  Its also a workaround for
2013           NSC Geode SC-1100's buggy TSC, which loses time when the
2014           processor goes idle (as is done by the scheduler).  The
2015           other workaround is idle=poll boot option.
2016
2017 config OLPC
2018         bool "One Laptop Per Child support"
2019         depends on !X86_PAE
2020         select GPIOLIB
2021         select OF
2022         select OF_PROMTREE
2023         ---help---
2024           Add support for detecting the unique features of the OLPC
2025           XO hardware.
2026
2027 config OLPC_XO1_PM
2028         bool "OLPC XO-1 Power Management"
2029         depends on OLPC && MFD_CS5535 && PM_SLEEP
2030         select MFD_CORE
2031         ---help---
2032           Add support for poweroff and suspend of the OLPC XO-1 laptop.
2033
2034 config OLPC_XO1_RTC
2035         bool "OLPC XO-1 Real Time Clock"
2036         depends on OLPC_XO1_PM && RTC_DRV_CMOS
2037         ---help---
2038           Add support for the XO-1 real time clock, which can be used as a
2039           programmable wakeup source.
2040
2041 config OLPC_XO1_SCI
2042         bool "OLPC XO-1 SCI extras"
2043         depends on OLPC && OLPC_XO1_PM
2044         select POWER_SUPPLY
2045         select GPIO_CS5535
2046         select MFD_CORE
2047         ---help---
2048           Add support for SCI-based features of the OLPC XO-1 laptop:
2049            - EC-driven system wakeups
2050            - Power button
2051            - Ebook switch
2052            - Lid switch
2053            - AC adapter status updates
2054            - Battery status updates
2055
2056 config OLPC_XO15_SCI
2057         bool "OLPC XO-1.5 SCI extras"
2058         depends on OLPC && ACPI
2059         select POWER_SUPPLY
2060         ---help---
2061           Add support for SCI-based features of the OLPC XO-1.5 laptop:
2062            - EC-driven system wakeups
2063            - AC adapter status updates
2064            - Battery status updates
2065
2066 endif # X86_32
2067
2068 config AMD_NB
2069         def_bool y
2070         depends on CPU_SUP_AMD && PCI
2071
2072 source "drivers/pcmcia/Kconfig"
2073
2074 source "drivers/pci/hotplug/Kconfig"
2075
2076 config RAPIDIO
2077         bool "RapidIO support"
2078         depends on PCI
2079         default n
2080         help
2081           If you say Y here, the kernel will include drivers and
2082           infrastructure code to support RapidIO interconnect devices.
2083
2084 source "drivers/rapidio/Kconfig"
2085
2086 endmenu
2087
2088
2089 menu "Executable file formats / Emulations"
2090
2091 source "fs/Kconfig.binfmt"
2092
2093 config IA32_EMULATION
2094         bool "IA32 Emulation"
2095         depends on X86_64
2096         select COMPAT_BINFMT_ELF
2097         ---help---
2098           Include code to run 32-bit programs under a 64-bit kernel. You should
2099           likely turn this on, unless you're 100% sure that you don't have any
2100           32-bit programs left.
2101
2102 config IA32_AOUT
2103         tristate "IA32 a.out support"
2104         depends on IA32_EMULATION
2105         ---help---
2106           Support old a.out binaries in the 32bit emulation.
2107
2108 config COMPAT
2109         def_bool y
2110         depends on IA32_EMULATION
2111
2112 config COMPAT_FOR_U64_ALIGNMENT
2113         def_bool COMPAT
2114         depends on X86_64
2115
2116 config SYSVIPC_COMPAT
2117         def_bool y
2118         depends on COMPAT && SYSVIPC
2119
2120 config KEYS_COMPAT
2121         bool
2122         depends on COMPAT && KEYS
2123         default y
2124
2125 endmenu
2126
2127
2128 config HAVE_ATOMIC_IOMAP
2129         def_bool y
2130         depends on X86_32
2131
2132 config HAVE_TEXT_POKE_SMP
2133         bool
2134         select STOP_MACHINE if SMP
2135
2136 source "net/Kconfig"
2137
2138 source "drivers/Kconfig"
2139
2140 source "drivers/firmware/Kconfig"
2141
2142 source "fs/Kconfig"
2143
2144 source "arch/x86/Kconfig.debug"
2145
2146 source "security/Kconfig"
2147
2148 source "crypto/Kconfig"
2149
2150 source "arch/x86/kvm/Kconfig"
2151
2152 source "lib/Kconfig"