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 HAVE_MIXED_BREAKPOINTS_REGS
  57         select PERF_EVENTS
  58         select HAVE_PERF_EVENTS_NMI
  59         select ANON_INODES
  60         select HAVE_ARCH_KMEMCHECK
  61         select HAVE_USER_RETURN_NOTIFIER
  62         select HAVE_ARCH_JUMP_LABEL if !CC_OPTIMIZE_FOR_SIZE
  63
  64 config INSTRUCTION_DECODER
  65         def_bool (KPROBES || PERF_EVENTS)
  66
  67 config OUTPUT_FORMAT
  68         string
  69         default "elf32-i386" if X86_32
  70         default "elf64-x86-64" if X86_64
  71
  72 config ARCH_DEFCONFIG
  73         string
  74         default "arch/x86/configs/i386_defconfig" if X86_32
  75         default "arch/x86/configs/x86_64_defconfig" if X86_64
  76
  77 config GENERIC_CMOS_UPDATE
  78         def_bool y
  79
  80 config CLOCKSOURCE_WATCHDOG
  81         def_bool y
  82
  83 config GENERIC_CLOCKEVENTS
  84         def_bool y
  85
  86 config GENERIC_CLOCKEVENTS_BROADCAST
  87         def_bool y
  88         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  89
  90 config LOCKDEP_SUPPORT
  91         def_bool y
  92
  93 config STACKTRACE_SUPPORT
  94         def_bool y
  95
  96 config HAVE_LATENCYTOP_SUPPORT
  97         def_bool y
  98
  99 config MMU
 100         def_bool y
 101
 102 config ZONE_DMA
 103         def_bool y
 104
 105 config SBUS
 106         bool
 107
 108 config NEED_DMA_MAP_STATE
 109        def_bool (X86_64 || DMAR || DMA_API_DEBUG)
 110
 111 config NEED_SG_DMA_LENGTH
 112         def_bool y
 113
 114 config GENERIC_ISA_DMA
 115         def_bool y
 116
 117 config GENERIC_IOMAP
 118         def_bool y
 119
 120 config GENERIC_BUG
 121         def_bool y
 122         depends on BUG
 123         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 124
 125 config GENERIC_BUG_RELATIVE_POINTERS
 126         bool
 127
 128 config GENERIC_HWEIGHT
 129         def_bool y
 130
 131 config GENERIC_GPIO
 132         bool
 133
 134 config ARCH_MAY_HAVE_PC_FDC
 135         def_bool y
 136
 137 config RWSEM_GENERIC_SPINLOCK
 138         def_bool !X86_XADD
 139
 140 config RWSEM_XCHGADD_ALGORITHM
 141         def_bool X86_XADD
 142
 143 config ARCH_HAS_CPU_IDLE_WAIT
 144         def_bool y
 145
 146 config GENERIC_CALIBRATE_DELAY
 147         def_bool y
 148
 149 config GENERIC_TIME_VSYSCALL
 150         bool
 151         default X86_64
 152
 153 config ARCH_HAS_CPU_RELAX
 154         def_bool y
 155
 156 config ARCH_HAS_DEFAULT_IDLE
 157         def_bool y
 158
 159 config ARCH_HAS_CACHE_LINE_SIZE
 160         def_bool y
 161
 162 config HAVE_SETUP_PER_CPU_AREA
 163         def_bool y
 164
 165 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 166         def_bool y
 167
 168 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 169         def_bool y
 170
 171 config HAVE_CPUMASK_OF_CPU_MAP
 172         def_bool X86_64_SMP
 173
 174 config ARCH_HIBERNATION_POSSIBLE
 175         def_bool y
 176
 177 config ARCH_SUSPEND_POSSIBLE
 178         def_bool y
 179
 180 config ZONE_DMA32
 181         bool
 182         default X86_64
 183
 184 config ARCH_POPULATES_NODE_MAP
 185         def_bool y
 186
 187 config AUDIT_ARCH
 188         bool
 189         default X86_64
 190
 191 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 192         def_bool y
 193
 194 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 195         def_bool y
 196
 197 config HAVE_EARLY_RES
 198         def_bool y
 199
 200 config HAVE_INTEL_TXT
 201         def_bool y
 202         depends on EXPERIMENTAL && DMAR && ACPI
 203
 204 # Use the generic interrupt handling code in kernel/irq/:
 205 config GENERIC_HARDIRQS
 206         def_bool y
 207
 208 config GENERIC_HARDIRQS_NO__DO_IRQ
 209        def_bool y
 210
 211 config GENERIC_IRQ_PROBE
 212         def_bool y
 213
 214 config GENERIC_PENDING_IRQ
 215         def_bool y
 216         depends on GENERIC_HARDIRQS && SMP
 217
 218 config USE_GENERIC_SMP_HELPERS
 219         def_bool y
 220         depends on SMP
 221
 222 config X86_32_SMP
 223         def_bool y
 224         depends on X86_32 && SMP
 225
 226 config X86_64_SMP
 227         def_bool y
 228         depends on X86_64 && SMP
 229
 230 config X86_HT
 231         def_bool y
 232         depends on SMP
 233
 234 config X86_TRAMPOLINE
 235         def_bool y
 236         depends on SMP || (64BIT && ACPI_SLEEP)
 237
 238 config X86_32_LAZY_GS
 239         def_bool y
 240         depends on X86_32 && !CC_STACKPROTECTOR
 241
 242 config ARCH_HWEIGHT_CFLAGS
 243         string
 244         default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
 245         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
 246
 247 config KTIME_SCALAR
 248         def_bool X86_32
 249
 250 config ARCH_CPU_PROBE_RELEASE
 251         def_bool y
 252         depends on HOTPLUG_CPU
 253
 254 source "init/Kconfig"
 255 source "kernel/Kconfig.freezer"
 256
 257 menu "Processor type and features"
 258
 259 source "kernel/time/Kconfig"
 260
 261 config SMP
 262         bool "Symmetric multi-processing support"
 263         ---help---
 264           This enables support for systems with more than one CPU. If you have
 265           a system with only one CPU, like most personal computers, say N. If
 266           you have a system with more than one CPU, say Y.
 267
 268           If you say N here, the kernel will run on single and multiprocessor
 269           machines, but will use only one CPU of a multiprocessor machine. If
 270           you say Y here, the kernel will run on many, but not all,
 271           singleprocessor machines. On a singleprocessor machine, the kernel
 272           will run faster if you say N here.
 273
 274           Note that if you say Y here and choose architecture "586" or
 275           "Pentium" under "Processor family", the kernel will not work on 486
 276           architectures. Similarly, multiprocessor kernels for the "PPro"
 277           architecture may not work on all Pentium based boards.
 278
 279           People using multiprocessor machines who say Y here should also say
 280           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 281           Management" code will be disabled if you say Y here.
 282
 283           See also <file:Documentation/i386/IO-APIC.txt>,
 284           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 285           <http://www.tldp.org/docs.html#howto>.
 286
 287           If you don't know what to do here, say N.
 288
 289 config X86_X2APIC
 290         bool "Support x2apic"
 291         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 292         ---help---
 293           This enables x2apic support on CPUs that have this feature.
 294
 295           This allows 32-bit apic IDs (so it can support very large systems),
 296           and accesses the local apic via MSRs not via mmio.
 297
 298           If you don't know what to do here, say N.
 299
 300 config SPARSE_IRQ
 301         bool "Support sparse irq numbering"
 302         depends on PCI_MSI || HT_IRQ
 303         ---help---
 304           This enables support for sparse irqs. This is useful for distro
 305           kernels that want to define a high CONFIG_NR_CPUS value but still
 306           want to have low kernel memory footprint on smaller machines.
 307
 308           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 309             out the irq_desc[] array in a more NUMA-friendly way. )
 310
 311           If you don't know what to do here, say N.
 312
 313 config NUMA_IRQ_DESC
 314         def_bool y
 315         depends on SPARSE_IRQ && NUMA
 316
 317 config X86_MPPARSE
 318         bool "Enable MPS table" if ACPI
 319         default y
 320         depends on X86_LOCAL_APIC
 321         ---help---
 322           For old smp systems that do not have proper acpi support. Newer systems
 323           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 324
 325 config X86_BIGSMP
 326         bool "Support for big SMP systems with more than 8 CPUs"
 327         depends on X86_32 && SMP
 328         ---help---
 329           This option is needed for the systems that have more than 8 CPUs
 330
 331 if X86_32
 332 config X86_EXTENDED_PLATFORM
 333         bool "Support for extended (non-PC) x86 platforms"
 334         default y
 335         ---help---
 336           If you disable this option then the kernel will only support
 337           standard PC platforms. (which covers the vast majority of
 338           systems out there.)
 339
 340           If you enable this option then you'll be able to select support
 341           for the following (non-PC) 32 bit x86 platforms:
 342                 AMD Elan
 343                 NUMAQ (IBM/Sequent)
 344                 RDC R-321x SoC
 345                 SGI 320/540 (Visual Workstation)
 346                 Summit/EXA (IBM x440)
 347                 Unisys ES7000 IA32 series
 348                 Moorestown MID devices
 349
 350           If you have one of these systems, or if you want to build a
 351           generic distribution kernel, say Y here - otherwise say N.
 352 endif
 353
 354 if X86_64
 355 config X86_EXTENDED_PLATFORM
 356         bool "Support for extended (non-PC) x86 platforms"
 357         default y
 358         ---help---
 359           If you disable this option then the kernel will only support
 360           standard PC platforms. (which covers the vast majority of
 361           systems out there.)
 362
 363           If you enable this option then you'll be able to select support
 364           for the following (non-PC) 64 bit x86 platforms:
 365                 ScaleMP vSMP
 366                 SGI Ultraviolet
 367
 368           If you have one of these systems, or if you want to build a
 369           generic distribution kernel, say Y here - otherwise say N.
 370 endif
 371 # This is an alphabetically sorted list of 64 bit extended platforms
 372 # Please maintain the alphabetic order if and when there are additions
 373
 374 config X86_VSMP
 375         bool "ScaleMP vSMP"
 376         select PARAVIRT
 377         depends on X86_64 && PCI
 378         depends on X86_EXTENDED_PLATFORM
 379         ---help---
 380           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 381           supposed to run on these EM64T-based machines.  Only choose this option
 382           if you have one of these machines.
 383
 384 config X86_UV
 385         bool "SGI Ultraviolet"
 386         depends on X86_64
 387         depends on X86_EXTENDED_PLATFORM
 388         depends on NUMA
 389         depends on X86_X2APIC
 390         ---help---
 391           This option is needed in order to support SGI Ultraviolet systems.
 392           If you don't have one of these, you should say N here.
 393
 394 # Following is an alphabetically sorted list of 32 bit extended platforms
 395 # Please maintain the alphabetic order if and when there are additions
 396
 397 config X86_ELAN
 398         bool "AMD Elan"
 399         depends on X86_32
 400         depends on X86_EXTENDED_PLATFORM
 401         ---help---
 402           Select this for an AMD Elan processor.
 403
 404           Do not use this option for K6/Athlon/Opteron processors!
 405
 406           If unsure, choose "PC-compatible" instead.
 407
 408 config X86_MRST
 409        bool "Moorestown MID platform"
 410         depends on PCI
 411         depends on PCI_GOANY
 412         depends on X86_32
 413         depends on X86_EXTENDED_PLATFORM
 414         depends on X86_IO_APIC
 415         select APB_TIMER
 416         ---help---
 417           Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 418           Internet Device(MID) platform. Moorestown consists of two chips:
 419           Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
 420           Unlike standard x86 PCs, Moorestown does not have many legacy devices
 421           nor standard legacy replacement devices/features. e.g. Moorestown does
 422           not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
 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 SCHED_OMIT_FRAME_POINTER
 498         def_bool y
 499         prompt "Single-depth WCHAN output"
 500         depends on X86
 501         ---help---
 502           Calculate simpler /proc/<PID>/wchan values. If this option
 503           is disabled then wchan values will recurse back to the
 504           caller function. This provides more accurate wchan values,
 505           at the expense of slightly more scheduling overhead.
 506
 507           If in doubt, say "Y".
 508
 509 menuconfig PARAVIRT_GUEST
 510         bool "Paravirtualized guest support"
 511         ---help---
 512           Say Y here to get to see options related to running Linux under
 513           various hypervisors.  This option alone does not add any kernel code.
 514
 515           If you say N, all options in this submenu will be skipped and disabled.
 516
 517 if PARAVIRT_GUEST
 518
 519 source "arch/x86/xen/Kconfig"
 520
 521 config VMI
 522         bool "VMI Guest support (DEPRECATED)"
 523         select PARAVIRT
 524         depends on X86_32
 525         ---help---
 526           VMI provides a paravirtualized interface to the VMware ESX server
 527           (it could be used by other hypervisors in theory too, but is not
 528           at the moment), by linking the kernel to a GPL-ed ROM module
 529           provided by the hypervisor.
 530
 531           As of September 2009, VMware has started a phased retirement
 532           of this feature from VMware's products. Please see
 533           feature-removal-schedule.txt for details.  If you are
 534           planning to enable this option, please note that you cannot
 535           live migrate a VMI enabled VM to a future VMware product,
 536           which doesn't support VMI. So if you expect your kernel to
 537           seamlessly migrate to newer VMware products, keep this
 538           disabled.
 539
 540 config KVM_CLOCK
 541         bool "KVM paravirtualized clock"
 542         select PARAVIRT
 543         select PARAVIRT_CLOCK
 544         ---help---
 545           Turning on this option will allow you to run a paravirtualized clock
 546           when running over the KVM hypervisor. Instead of relying on a PIT
 547           (or probably other) emulation by the underlying device model, the host
 548           provides the guest with timing infrastructure such as time of day, and
 549           system time
 550
 551 config KVM_GUEST
 552         bool "KVM Guest support"
 553         select PARAVIRT
 554         ---help---
 555           This option enables various optimizations for running under the KVM
 556           hypervisor.
 557
 558 source "arch/x86/lguest/Kconfig"
 559
 560 config PARAVIRT
 561         bool "Enable paravirtualization code"
 562         ---help---
 563           This changes the kernel so it can modify itself when it is run
 564           under a hypervisor, potentially improving performance significantly
 565           over full virtualization.  However, when run without a hypervisor
 566           the kernel is theoretically slower and slightly larger.
 567
 568 config PARAVIRT_SPINLOCKS
 569         bool "Paravirtualization layer for spinlocks"
 570         depends on PARAVIRT && SMP && EXPERIMENTAL
 571         ---help---
 572           Paravirtualized spinlocks allow a pvops backend to replace the
 573           spinlock implementation with something virtualization-friendly
 574           (for example, block the virtual CPU rather than spinning).
 575
 576           Unfortunately the downside is an up to 5% performance hit on
 577           native kernels, with various workloads.
 578
 579           If you are unsure how to answer this question, answer N.
 580
 581 config PARAVIRT_CLOCK
 582         bool
 583
 584 endif
 585
 586 config PARAVIRT_DEBUG
 587         bool "paravirt-ops debugging"
 588         depends on PARAVIRT && DEBUG_KERNEL
 589         ---help---
 590           Enable to debug paravirt_ops internals.  Specifically, BUG if
 591           a paravirt_op is missing when it is called.
 592
 593 config NO_BOOTMEM
 594         default y
 595         bool "Disable Bootmem code"
 596         ---help---
 597           Use early_res directly instead of bootmem before slab is ready.
 598                 - allocator (buddy) [generic]
 599                 - early allocator (bootmem) [generic]
 600                 - very early allocator (reserve_early*()) [x86]
 601                 - very very early allocator (early brk model) [x86]
 602           So reduce one layer between early allocator to final allocator
 603
 604
 605 config MEMTEST
 606         bool "Memtest"
 607         ---help---
 608           This option adds a kernel parameter 'memtest', which allows memtest
 609           to be set.
 610                 memtest=0, mean disabled; -- default
 611                 memtest=1, mean do 1 test pattern;
 612                 ...
 613                 memtest=4, mean do 4 test patterns.
 614           If you are unsure how to answer this question, answer N.
 615
 616 config X86_SUMMIT_NUMA
 617         def_bool y
 618         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 619
 620 config X86_CYCLONE_TIMER
 621         def_bool y
 622         depends on X86_32_NON_STANDARD
 623
 624 source "arch/x86/Kconfig.cpu"
 625
 626 config HPET_TIMER
 627         def_bool X86_64
 628         prompt "HPET Timer Support" if X86_32
 629         ---help---
 630           Use the IA-PC HPET (High Precision Event Timer) to manage
 631           time in preference to the PIT and RTC, if a HPET is
 632           present.
 633           HPET is the next generation timer replacing legacy 8254s.
 634           The HPET provides a stable time base on SMP
 635           systems, unlike the TSC, but it is more expensive to access,
 636           as it is off-chip.  You can find the HPET spec at
 637           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 638
 639           You can safely choose Y here.  However, HPET will only be
 640           activated if the platform and the BIOS support this feature.
 641           Otherwise the 8254 will be used for timing services.
 642
 643           Choose N to continue using the legacy 8254 timer.
 644
 645 config HPET_EMULATE_RTC
 646         def_bool y
 647         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 648
 649 config APB_TIMER
 650        def_bool y if MRST
 651        prompt "Langwell APB Timer Support" if X86_MRST
 652        help
 653          APB timer is the replacement for 8254, HPET on X86 MID platforms.
 654          The APBT provides a stable time base on SMP
 655          systems, unlike the TSC, but it is more expensive to access,
 656          as it is off-chip. APB timers are always running regardless of CPU
 657          C states, they are used as per CPU clockevent device when possible.
 658
 659 # Mark as embedded because too many people got it wrong.
 660 # The code disables itself when not needed.
 661 config DMI
 662         default y
 663         bool "Enable DMI scanning" if EMBEDDED
 664         ---help---
 665           Enabled scanning of DMI to identify machine quirks. Say Y
 666           here unless you have verified that your setup is not
 667           affected by entries in the DMI blacklist. Required by PNP
 668           BIOS code.
 669
 670 config GART_IOMMU
 671         bool "GART IOMMU support" if EMBEDDED
 672         default y
 673         select SWIOTLB
 674         depends on X86_64 && PCI && K8_NB
 675         ---help---
 676           Support for full DMA access of devices with 32bit memory access only
 677           on systems with more than 3GB. This is usually needed for USB,
 678           sound, many IDE/SATA chipsets and some other devices.
 679           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 680           based hardware IOMMU and a software bounce buffer based IOMMU used
 681           on Intel systems and as fallback.
 682           The code is only active when needed (enough memory and limited
 683           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 684           too.
 685
 686 config CALGARY_IOMMU
 687         bool "IBM Calgary IOMMU support"
 688         select SWIOTLB
 689         depends on X86_64 && PCI && EXPERIMENTAL
 690         ---help---
 691           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 692           systems. Needed to run systems with more than 3GB of memory
 693           properly with 32-bit PCI devices that do not support DAC
 694           (Double Address Cycle). Calgary also supports bus level
 695           isolation, where all DMAs pass through the IOMMU.  This
 696           prevents them from going anywhere except their intended
 697           destination. This catches hard-to-find kernel bugs and
 698           mis-behaving drivers and devices that do not use the DMA-API
 699           properly to set up their DMA buffers.  The IOMMU can be
 700           turned off at boot time with the iommu=off parameter.
 701           Normally the kernel will make the right choice by itself.
 702           If unsure, say Y.
 703
 704 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 705         def_bool y
 706         prompt "Should Calgary be enabled by default?"
 707         depends on CALGARY_IOMMU
 708         ---help---
 709           Should Calgary be enabled by default? if you choose 'y', Calgary
 710           will be used (if it exists). If you choose 'n', Calgary will not be
 711           used even if it exists. If you choose 'n' and would like to use
 712           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 713           If unsure, say Y.
 714
 715 config AMD_IOMMU
 716         bool "AMD IOMMU support"
 717         select SWIOTLB
 718         select PCI_MSI
 719         depends on X86_64 && PCI && ACPI
 720         ---help---
 721           With this option you can enable support for AMD IOMMU hardware in
 722           your system. An IOMMU is a hardware component which provides
 723           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 724           can isolate the the DMA memory of different devices and protect the
 725           system from misbehaving device drivers or hardware.
 726
 727           You can find out if your system has an AMD IOMMU if you look into
 728           your BIOS for an option to enable it or if you have an IVRS ACPI
 729           table.
 730
 731 config AMD_IOMMU_STATS
 732         bool "Export AMD IOMMU statistics to debugfs"
 733         depends on AMD_IOMMU
 734         select DEBUG_FS
 735         ---help---
 736           This option enables code in the AMD IOMMU driver to collect various
 737           statistics about whats happening in the driver and exports that
 738           information to userspace via debugfs.
 739           If unsure, say N.
 740
 741 # need this always selected by IOMMU for the VIA workaround
 742 config SWIOTLB
 743         def_bool y if X86_64
 744         ---help---
 745           Support for software bounce buffers used on x86-64 systems
 746           which don't have a hardware IOMMU (e.g. the current generation
 747           of Intel's x86-64 CPUs). Using this PCI devices which can only
 748           access 32-bits of memory can be used on systems with more than
 749           3 GB of memory. If unsure, say Y.
 750
 751 config IOMMU_HELPER
 752         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 753
 754 config IOMMU_API
 755         def_bool (AMD_IOMMU || DMAR)
 756
 757 config MAXSMP
 758         bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 759         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 760         select CPUMASK_OFFSTACK
 761         ---help---
 762           Enable maximum number of CPUS and NUMA Nodes for this architecture.
 763           If unsure, say N.
 764
 765 config NR_CPUS
 766         int "Maximum number of CPUs" if SMP && !MAXSMP
 767         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 768         range 2 512 if SMP && !MAXSMP
 769         default "1" if !SMP
 770         default "4096" if MAXSMP
 771         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 772         default "8" if SMP
 773         ---help---
 774           This allows you to specify the maximum number of CPUs which this
 775           kernel will support.  The maximum supported value is 512 and the
 776           minimum value which makes sense is 2.
 777
 778           This is purely to save memory - each supported CPU adds
 779           approximately eight kilobytes to the kernel image.
 780
 781 config SCHED_SMT
 782         bool "SMT (Hyperthreading) scheduler support"
 783         depends on X86_HT
 784         ---help---
 785           SMT scheduler support improves the CPU scheduler's decision making
 786           when dealing with Intel Pentium 4 chips with HyperThreading at a
 787           cost of slightly increased overhead in some places. If unsure say
 788           N here.
 789
 790 config SCHED_MC
 791         def_bool y
 792         prompt "Multi-core scheduler support"
 793         depends on X86_HT
 794         ---help---
 795           Multi-core scheduler support improves the CPU scheduler's decision
 796           making when dealing with multi-core CPU chips at a cost of slightly
 797           increased overhead in some places. If unsure say N here.
 798
 799 source "kernel/Kconfig.preempt"
 800
 801 config X86_UP_APIC
 802         bool "Local APIC support on uniprocessors"
 803         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 804         ---help---
 805           A local APIC (Advanced Programmable Interrupt Controller) is an
 806           integrated interrupt controller in the CPU. If you have a single-CPU
 807           system which has a processor with a local APIC, you can say Y here to
 808           enable and use it. If you say Y here even though your machine doesn't
 809           have a local APIC, then the kernel will still run with no slowdown at
 810           all. The local APIC supports CPU-generated self-interrupts (timer,
 811           performance counters), and the NMI watchdog which detects hard
 812           lockups.
 813
 814 config X86_UP_IOAPIC
 815         bool "IO-APIC support on uniprocessors"
 816         depends on X86_UP_APIC
 817         ---help---
 818           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 819           SMP-capable replacement for PC-style interrupt controllers. Most
 820           SMP systems and many recent uniprocessor systems have one.
 821
 822           If you have a single-CPU system with an IO-APIC, you can say Y here
 823           to use it. If you say Y here even though your machine doesn't have
 824           an IO-APIC, then the kernel will still run with no slowdown at all.
 825
 826 config X86_LOCAL_APIC
 827         def_bool y
 828         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 829
 830 config X86_IO_APIC
 831         def_bool y
 832         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 833
 834 config X86_VISWS_APIC
 835         def_bool y
 836         depends on X86_32 && X86_VISWS
 837
 838 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 839         bool "Reroute for broken boot IRQs"
 840         depends on X86_IO_APIC
 841         ---help---
 842           This option enables a workaround that fixes a source of
 843           spurious interrupts. This is recommended when threaded
 844           interrupt handling is used on systems where the generation of
 845           superfluous "boot interrupts" cannot be disabled.
 846
 847           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 848           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 849           kernel does during interrupt handling). On chipsets where this
 850           boot IRQ generation cannot be disabled, this workaround keeps
 851           the original IRQ line masked so that only the equivalent "boot
 852           IRQ" is delivered to the CPUs. The workaround also tells the
 853           kernel to set up the IRQ handler on the boot IRQ line. In this
 854           way only one interrupt is delivered to the kernel. Otherwise
 855           the spurious second interrupt may cause the kernel to bring
 856           down (vital) interrupt lines.
 857
 858           Only affects "broken" chipsets. Interrupt sharing may be
 859           increased on these systems.
 860
 861 config X86_MCE
 862         bool "Machine Check / overheating reporting"
 863         ---help---
 864           Machine Check support allows the processor to notify the
 865           kernel if it detects a problem (e.g. overheating, data corruption).
 866           The action the kernel takes depends on the severity of the problem,
 867           ranging from warning messages to halting the machine.
 868
 869 config X86_MCE_INTEL
 870         def_bool y
 871         prompt "Intel MCE features"
 872         depends on X86_MCE && X86_LOCAL_APIC
 873         ---help---
 874            Additional support for intel specific MCE features such as
 875            the thermal monitor.
 876
 877 config X86_MCE_AMD
 878         def_bool y
 879         prompt "AMD MCE features"
 880         depends on X86_MCE && X86_LOCAL_APIC
 881         ---help---
 882            Additional support for AMD specific MCE features such as
 883            the DRAM Error Threshold.
 884
 885 config X86_ANCIENT_MCE
 886         bool "Support for old Pentium 5 / WinChip machine checks"
 887         depends on X86_32 && X86_MCE
 888         ---help---
 889           Include support for machine check handling on old Pentium 5 or WinChip
 890           systems. These typically need to be enabled explicitely on the command
 891           line.
 892
 893 config X86_MCE_THRESHOLD
 894         depends on X86_MCE_AMD || X86_MCE_INTEL
 895         def_bool y
 896
 897 config X86_MCE_INJECT
 898         depends on X86_MCE
 899         tristate "Machine check injector support"
 900         ---help---
 901           Provide support for injecting machine checks for testing purposes.
 902           If you don't know what a machine check is and you don't do kernel
 903           QA it is safe to say n.
 904
 905 config X86_THERMAL_VECTOR
 906         def_bool y
 907         depends on X86_MCE_INTEL
 908
 909 config VM86
 910         bool "Enable VM86 support" if EMBEDDED
 911         default y
 912         depends on X86_32
 913         ---help---
 914           This option is required by programs like DOSEMU to run 16-bit legacy
 915           code on X86 processors. It also may be needed by software like
 916           XFree86 to initialize some video cards via BIOS. Disabling this
 917           option saves about 6k.
 918
 919 config TOSHIBA
 920         tristate "Toshiba Laptop support"
 921         depends on X86_32
 922         ---help---
 923           This adds a driver to safely access the System Management Mode of
 924           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 925           not work on models with a Phoenix BIOS. The System Management Mode
 926           is used to set the BIOS and power saving options on Toshiba portables.
 927
 928           For information on utilities to make use of this driver see the
 929           Toshiba Linux utilities web site at:
 930           <http://www.buzzard.org.uk/toshiba/>.
 931
 932           Say Y if you intend to run this kernel on a Toshiba portable.
 933           Say N otherwise.
 934
 935 config I8K
 936         tristate "Dell laptop support"
 937         ---help---
 938           This adds a driver to safely access the System Management Mode
 939           of the CPU on the Dell Inspiron 8000. The System Management Mode
 940           is used to read cpu temperature and cooling fan status and to
 941           control the fans on the I8K portables.
 942
 943           This driver has been tested only on the Inspiron 8000 but it may
 944           also work with other Dell laptops. You can force loading on other
 945           models by passing the parameter `force=1' to the module. Use at
 946           your own risk.
 947
 948           For information on utilities to make use of this driver see the
 949           I8K Linux utilities web site at:
 950           <http://people.debian.org/~dz/i8k/>
 951
 952           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 953           Say N otherwise.
 954
 955 config X86_REBOOTFIXUPS
 956         bool "Enable X86 board specific fixups for reboot"
 957         depends on X86_32
 958         ---help---
 959           This enables chipset and/or board specific fixups to be done
 960           in order to get reboot to work correctly. This is only needed on
 961           some combinations of hardware and BIOS. The symptom, for which
 962           this config is intended, is when reboot ends with a stalled/hung
 963           system.
 964
 965           Currently, the only fixup is for the Geode machines using
 966           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 967
 968           Say Y if you want to enable the fixup. Currently, it's safe to
 969           enable this option even if you don't need it.
 970           Say N otherwise.
 971
 972 config MICROCODE
 973         tristate "/dev/cpu/microcode - microcode support"
 974         select FW_LOADER
 975         ---help---
 976           If you say Y here, you will be able to update the microcode on
 977           certain Intel and AMD processors. The Intel support is for the
 978           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 979           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 980           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 981           You will obviously need the actual microcode binary data itself
 982           which is not shipped with the Linux kernel.
 983
 984           This option selects the general module only, you need to select
 985           at least one vendor specific module as well.
 986
 987           To compile this driver as a module, choose M here: the
 988           module will be called microcode.
 989
 990 config MICROCODE_INTEL
 991         bool "Intel microcode patch loading support"
 992         depends on MICROCODE
 993         default MICROCODE
 994         select FW_LOADER
 995         ---help---
 996           This options enables microcode patch loading support for Intel
 997           processors.
 998
 999           For latest news and information on obtaining all the required
1000           Intel ingredients for this driver, check:
1001           <http://www.urbanmyth.org/microcode/>.
1002
1003 config MICROCODE_AMD
1004         bool "AMD microcode patch loading support"
1005         depends on MICROCODE
1006         select FW_LOADER
1007         ---help---
1008           If you select this option, microcode patch loading support for AMD
1009           processors will be enabled.
1010
1011 config MICROCODE_OLD_INTERFACE
1012         def_bool y
1013         depends on MICROCODE
1014
1015 config X86_MSR
1016         tristate "/dev/cpu/*/msr - Model-specific register support"
1017         ---help---
1018           This device gives privileged processes access to the x86
1019           Model-Specific Registers (MSRs).  It is a character device with
1020           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1021           MSR accesses are directed to a specific CPU on multi-processor
1022           systems.
1023
1024 config X86_CPUID
1025         tristate "/dev/cpu/*/cpuid - CPU information support"
1026         ---help---
1027           This device gives processes access to the x86 CPUID instruction to
1028           be executed on a specific processor.  It is a character device
1029           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1030           /dev/cpu/31/cpuid.
1031
1032 choice
1033         prompt "High Memory Support"
1034         default HIGHMEM64G if X86_NUMAQ
1035         default HIGHMEM4G
1036         depends on X86_32
1037
1038 config NOHIGHMEM
1039         bool "off"
1040         depends on !X86_NUMAQ
1041         ---help---
1042           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1043           However, the address space of 32-bit x86 processors is only 4
1044           Gigabytes large. That means that, if you have a large amount of
1045           physical memory, not all of it can be "permanently mapped" by the
1046           kernel. The physical memory that's not permanently mapped is called
1047           "high memory".
1048
1049           If you are compiling a kernel which will never run on a machine with
1050           more than 1 Gigabyte total physical RAM, answer "off" here (default
1051           choice and suitable for most users). This will result in a "3GB/1GB"
1052           split: 3GB are mapped so that each process sees a 3GB virtual memory
1053           space and the remaining part of the 4GB virtual memory space is used
1054           by the kernel to permanently map as much physical memory as
1055           possible.
1056
1057           If the machine has between 1 and 4 Gigabytes physical RAM, then
1058           answer "4GB" here.
1059
1060           If more than 4 Gigabytes is used then answer "64GB" here. This
1061           selection turns Intel PAE (Physical Address Extension) mode on.
1062           PAE implements 3-level paging on IA32 processors. PAE is fully
1063           supported by Linux, PAE mode is implemented on all recent Intel
1064           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1065           then the kernel will not boot on CPUs that don't support PAE!
1066
1067           The actual amount of total physical memory will either be
1068           auto detected or can be forced by using a kernel command line option
1069           such as "mem=256M". (Try "man bootparam" or see the documentation of
1070           your boot loader (lilo or loadlin) about how to pass options to the
1071           kernel at boot time.)
1072
1073           If unsure, say "off".
1074
1075 config HIGHMEM4G
1076         bool "4GB"
1077         depends on !X86_NUMAQ
1078         ---help---
1079           Select this if you have a 32-bit processor and between 1 and 4
1080           gigabytes of physical RAM.
1081
1082 config HIGHMEM64G
1083         bool "64GB"
1084         depends on !M386 && !M486
1085         select X86_PAE
1086         ---help---
1087           Select this if you have a 32-bit processor and more than 4
1088           gigabytes of physical RAM.
1089
1090 endchoice
1091
1092 choice
1093         depends on EXPERIMENTAL
1094         prompt "Memory split" if EMBEDDED
1095         default VMSPLIT_3G
1096         depends on X86_32
1097         ---help---
1098           Select the desired split between kernel and user memory.
1099
1100           If the address range available to the kernel is less than the
1101           physical memory installed, the remaining memory will be available
1102           as "high memory". Accessing high memory is a little more costly
1103           than low memory, as it needs to be mapped into the kernel first.
1104           Note that increasing the kernel address space limits the range
1105           available to user programs, making the address space there
1106           tighter.  Selecting anything other than the default 3G/1G split
1107           will also likely make your kernel incompatible with binary-only
1108           kernel modules.
1109
1110           If you are not absolutely sure what you are doing, leave this
1111           option alone!
1112
1113         config VMSPLIT_3G
1114                 bool "3G/1G user/kernel split"
1115         config VMSPLIT_3G_OPT
1116                 depends on !X86_PAE
1117                 bool "3G/1G user/kernel split (for full 1G low memory)"
1118         config VMSPLIT_2G
1119                 bool "2G/2G user/kernel split"
1120         config VMSPLIT_2G_OPT
1121                 depends on !X86_PAE
1122                 bool "2G/2G user/kernel split (for full 2G low memory)"
1123         config VMSPLIT_1G
1124                 bool "1G/3G user/kernel split"
1125 endchoice
1126
1127 config PAGE_OFFSET
1128         hex
1129         default 0xB0000000 if VMSPLIT_3G_OPT
1130         default 0x80000000 if VMSPLIT_2G
1131         default 0x78000000 if VMSPLIT_2G_OPT
1132         default 0x40000000 if VMSPLIT_1G
1133         default 0xC0000000
1134         depends on X86_32
1135
1136 config HIGHMEM
1137         def_bool y
1138         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1139
1140 config X86_PAE
1141         bool "PAE (Physical Address Extension) Support"
1142         depends on X86_32 && !HIGHMEM4G
1143         ---help---
1144           PAE is required for NX support, and furthermore enables
1145           larger swapspace support for non-overcommit purposes. It
1146           has the cost of more pagetable lookup overhead, and also
1147           consumes more pagetable space per process.
1148
1149 config ARCH_PHYS_ADDR_T_64BIT
1150         def_bool X86_64 || X86_PAE
1151
1152 config DIRECT_GBPAGES
1153         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1154         default y
1155         depends on X86_64
1156         ---help---
1157           Allow the kernel linear mapping to use 1GB pages on CPUs that
1158           support it. This can improve the kernel's performance a tiny bit by
1159           reducing TLB pressure. If in doubt, say "Y".
1160
1161 # Common NUMA Features
1162 config NUMA
1163         bool "Numa Memory Allocation and Scheduler Support"
1164         depends on SMP
1165         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1166         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1167         ---help---
1168           Enable NUMA (Non Uniform Memory Access) support.
1169
1170           The kernel will try to allocate memory used by a CPU on the
1171           local memory controller of the CPU and add some more
1172           NUMA awareness to the kernel.
1173
1174           For 64-bit this is recommended if the system is Intel Core i7
1175           (or later), AMD Opteron, or EM64T NUMA.
1176
1177           For 32-bit this is only needed on (rare) 32-bit-only platforms
1178           that support NUMA topologies, such as NUMAQ / Summit, or if you
1179           boot a 32-bit kernel on a 64-bit NUMA platform.
1180
1181           Otherwise, you should say N.
1182
1183 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1184         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1185
1186 config K8_NUMA
1187         def_bool y
1188         prompt "Old style AMD Opteron NUMA detection"
1189         depends on X86_64 && NUMA && PCI
1190         ---help---
1191           Enable K8 NUMA node topology detection.  You should say Y here if
1192           you have a multi processor AMD K8 system. This uses an old
1193           method to read the NUMA configuration directly from the builtin
1194           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1195           instead, which also takes priority if both are compiled in.
1196
1197 config X86_64_ACPI_NUMA
1198         def_bool y
1199         prompt "ACPI NUMA detection"
1200         depends on X86_64 && NUMA && ACPI && PCI
1201         select ACPI_NUMA
1202         ---help---
1203           Enable ACPI SRAT based node topology detection.
1204
1205 # Some NUMA nodes have memory ranges that span
1206 # other nodes.  Even though a pfn is valid and
1207 # between a node's start and end pfns, it may not
1208 # reside on that node.  See memmap_init_zone()
1209 # for details.
1210 config NODES_SPAN_OTHER_NODES
1211         def_bool y
1212         depends on X86_64_ACPI_NUMA
1213
1214 config NUMA_EMU
1215         bool "NUMA emulation"
1216         depends on X86_64 && NUMA
1217         ---help---
1218           Enable NUMA emulation. A flat machine will be split
1219           into virtual nodes when booted with "numa=fake=N", where N is the
1220           number of nodes. This is only useful for debugging.
1221
1222 config NODES_SHIFT
1223         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1224         range 1 10
1225         default "10" if MAXSMP
1226         default "6" if X86_64
1227         default "4" if X86_NUMAQ
1228         default "3"
1229         depends on NEED_MULTIPLE_NODES
1230         ---help---
1231           Specify the maximum number of NUMA Nodes available on the target
1232           system.  Increases memory reserved to accommodate various tables.
1233
1234 config HAVE_ARCH_BOOTMEM
1235         def_bool y
1236         depends on X86_32 && NUMA
1237
1238 config ARCH_HAVE_MEMORY_PRESENT
1239         def_bool y
1240         depends on X86_32 && DISCONTIGMEM
1241
1242 config NEED_NODE_MEMMAP_SIZE
1243         def_bool y
1244         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1245
1246 config HAVE_ARCH_ALLOC_REMAP
1247         def_bool y
1248         depends on X86_32 && NUMA
1249
1250 config ARCH_FLATMEM_ENABLE
1251         def_bool y
1252         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1253
1254 config ARCH_DISCONTIGMEM_ENABLE
1255         def_bool y
1256         depends on NUMA && X86_32
1257
1258 config ARCH_DISCONTIGMEM_DEFAULT
1259         def_bool y
1260         depends on NUMA && X86_32
1261
1262 config ARCH_PROC_KCORE_TEXT
1263         def_bool y
1264         depends on X86_64 && PROC_KCORE
1265
1266 config ARCH_SPARSEMEM_DEFAULT
1267         def_bool y
1268         depends on X86_64
1269
1270 config ARCH_SPARSEMEM_ENABLE
1271         def_bool y
1272         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1273         select SPARSEMEM_STATIC if X86_32
1274         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1275
1276 config ARCH_SELECT_MEMORY_MODEL
1277         def_bool y
1278         depends on ARCH_SPARSEMEM_ENABLE
1279
1280 config ARCH_MEMORY_PROBE
1281         def_bool X86_64
1282         depends on MEMORY_HOTPLUG
1283
1284 config ILLEGAL_POINTER_VALUE
1285        hex
1286        default 0 if X86_32
1287        default 0xdead000000000000 if X86_64
1288
1289 source "mm/Kconfig"
1290
1291 config HIGHPTE
1292         bool "Allocate 3rd-level pagetables from highmem"
1293         depends on HIGHMEM
1294         ---help---
1295           The VM uses one page table entry for each page of physical memory.
1296           For systems with a lot of RAM, this can be wasteful of precious
1297           low memory.  Setting this option will put user-space page table
1298           entries in high memory.
1299
1300 config X86_CHECK_BIOS_CORRUPTION
1301         bool "Check for low memory corruption"
1302         ---help---
1303           Periodically check for memory corruption in low memory, which
1304           is suspected to be caused by BIOS.  Even when enabled in the
1305           configuration, it is disabled at runtime.  Enable it by
1306           setting "memory_corruption_check=1" on the kernel command
1307           line.  By default it scans the low 64k of memory every 60
1308           seconds; see the memory_corruption_check_size and
1309           memory_corruption_check_period parameters in
1310           Documentation/kernel-parameters.txt to adjust this.
1311
1312           When enabled with the default parameters, this option has
1313           almost no overhead, as it reserves a relatively small amount
1314           of memory and scans it infrequently.  It both detects corruption
1315           and prevents it from affecting the running system.
1316
1317           It is, however, intended as a diagnostic tool; if repeatable
1318           BIOS-originated corruption always affects the same memory,
1319           you can use memmap= to prevent the kernel from using that
1320           memory.
1321
1322 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1323         bool "Set the default setting of memory_corruption_check"
1324         depends on X86_CHECK_BIOS_CORRUPTION
1325         default y
1326         ---help---
1327           Set whether the default state of memory_corruption_check is
1328           on or off.
1329
1330 config X86_RESERVE_LOW_64K
1331         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1332         default y
1333         ---help---
1334           Reserve the first 64K of physical RAM on BIOSes that are known
1335           to potentially corrupt that memory range. A numbers of BIOSes are
1336           known to utilize this area during suspend/resume, so it must not
1337           be used by the kernel.
1338
1339           Set this to N if you are absolutely sure that you trust the BIOS
1340           to get all its memory reservations and usages right.
1341
1342           If you have doubts about the BIOS (e.g. suspend/resume does not
1343           work or there's kernel crashes after certain hardware hotplug
1344           events) and it's not AMI or Phoenix, then you might want to enable
1345           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1346           corruption patterns.
1347
1348           Say Y if unsure.
1349
1350 config MATH_EMULATION
1351         bool
1352         prompt "Math emulation" if X86_32
1353         ---help---
1354           Linux can emulate a math coprocessor (used for floating point
1355           operations) if you don't have one. 486DX and Pentium processors have
1356           a math coprocessor built in, 486SX and 386 do not, unless you added
1357           a 487DX or 387, respectively. (The messages during boot time can
1358           give you some hints here ["man dmesg"].) Everyone needs either a
1359           coprocessor or this emulation.
1360
1361           If you don't have a math coprocessor, you need to say Y here; if you
1362           say Y here even though you have a coprocessor, the coprocessor will
1363           be used nevertheless. (This behavior can be changed with the kernel
1364           command line option "no387", which comes handy if your coprocessor
1365           is broken. Try "man bootparam" or see the documentation of your boot
1366           loader (lilo or loadlin) about how to pass options to the kernel at
1367           boot time.) This means that it is a good idea to say Y here if you
1368           intend to use this kernel on different machines.
1369
1370           More information about the internals of the Linux math coprocessor
1371           emulation can be found in <file:arch/x86/math-emu/README>.
1372
1373           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1374           kernel, it won't hurt.
1375
1376 config MTRR
1377         def_bool y
1378         prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1379         ---help---
1380           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1381           the Memory Type Range Registers (MTRRs) may be used to control
1382           processor access to memory ranges. This is most useful if you have
1383           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1384           allows bus write transfers to be combined into a larger transfer
1385           before bursting over the PCI/AGP bus. This can increase performance
1386           of image write operations 2.5 times or more. Saying Y here creates a
1387           /proc/mtrr file which may be used to manipulate your processor's
1388           MTRRs. Typically the X server should use this.
1389
1390           This code has a reasonably generic interface so that similar
1391           control registers on other processors can be easily supported
1392           as well:
1393
1394           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1395           Registers (ARRs) which provide a similar functionality to MTRRs. For
1396           these, the ARRs are used to emulate the MTRRs.
1397           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1398           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1399           write-combining. All of these processors are supported by this code
1400           and it makes sense to say Y here if you have one of them.
1401
1402           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1403           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1404           can lead to all sorts of problems, so it's good to say Y here.
1405
1406           You can safely say Y even if your machine doesn't have MTRRs, you'll
1407           just add about 9 KB to your kernel.
1408
1409           See <file:Documentation/x86/mtrr.txt> for more information.
1410
1411 config MTRR_SANITIZER
1412         def_bool y
1413         prompt "MTRR cleanup support"
1414         depends on MTRR
1415         ---help---
1416           Convert MTRR layout from continuous to discrete, so X drivers can
1417           add writeback entries.
1418
1419           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1420           The largest mtrr entry size for a continuous block can be set with
1421           mtrr_chunk_size.
1422
1423           If unsure, say Y.
1424
1425 config MTRR_SANITIZER_ENABLE_DEFAULT
1426         int "MTRR cleanup enable value (0-1)"
1427         range 0 1
1428         default "0"
1429         depends on MTRR_SANITIZER
1430         ---help---
1431           Enable mtrr cleanup default value
1432
1433 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1434         int "MTRR cleanup spare reg num (0-7)"
1435         range 0 7
1436         default "1"
1437         depends on MTRR_SANITIZER
1438         ---help---
1439           mtrr cleanup spare entries default, it can be changed via
1440           mtrr_spare_reg_nr=N on the kernel command line.
1441
1442 config X86_PAT
1443         def_bool y
1444         prompt "x86 PAT support" if EMBEDDED
1445         depends on MTRR
1446         ---help---
1447           Use PAT attributes to setup page level cache control.
1448
1449           PATs are the modern equivalents of MTRRs and are much more
1450           flexible than MTRRs.
1451
1452           Say N here if you see bootup problems (boot crash, boot hang,
1453           spontaneous reboots) or a non-working video driver.
1454
1455           If unsure, say Y.
1456
1457 config ARCH_USES_PG_UNCACHED
1458         def_bool y
1459         depends on X86_PAT
1460
1461 config EFI
1462         bool "EFI runtime service support"
1463         depends on ACPI
1464         ---help---
1465           This enables the kernel to use EFI runtime services that are
1466           available (such as the EFI variable services).
1467
1468           This option is only useful on systems that have EFI firmware.
1469           In addition, you should use the latest ELILO loader available
1470           at <http://elilo.sourceforge.net> in order to take advantage
1471           of EFI runtime services. However, even with this option, the
1472           resultant kernel should continue to boot on existing non-EFI
1473           platforms.
1474
1475 config SECCOMP
1476         def_bool y
1477         prompt "Enable seccomp to safely compute untrusted bytecode"
1478         ---help---
1479           This kernel feature is useful for number crunching applications
1480           that may need to compute untrusted bytecode during their
1481           execution. By using pipes or other transports made available to
1482           the process as file descriptors supporting the read/write
1483           syscalls, it's possible to isolate those applications in
1484           their own address space using seccomp. Once seccomp is
1485           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1486           and the task is only allowed to execute a few safe syscalls
1487           defined by each seccomp mode.
1488
1489           If unsure, say Y. Only embedded should say N here.
1490
1491 config CC_STACKPROTECTOR
1492         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1493         ---help---
1494           This option turns on the -fstack-protector GCC feature. This
1495           feature puts, at the beginning of functions, a canary value on
1496           the stack just before the return address, and validates
1497           the value just before actually returning.  Stack based buffer
1498           overflows (that need to overwrite this return address) now also
1499           overwrite the canary, which gets detected and the attack is then
1500           neutralized via a kernel panic.
1501
1502           This feature requires gcc version 4.2 or above, or a distribution
1503           gcc with the feature backported. Older versions are automatically
1504           detected and for those versions, this configuration option is
1505           ignored. (and a warning is printed during bootup)
1506
1507 source kernel/Kconfig.hz
1508
1509 config KEXEC
1510         bool "kexec system call"
1511         ---help---
1512           kexec is a system call that implements the ability to shutdown your
1513           current kernel, and to start another kernel.  It is like a reboot
1514           but it is independent of the system firmware.   And like a reboot
1515           you can start any kernel with it, not just Linux.
1516
1517           The name comes from the similarity to the exec system call.
1518
1519           It is an ongoing process to be certain the hardware in a machine
1520           is properly shutdown, so do not be surprised if this code does not
1521           initially work for you.  It may help to enable device hotplugging
1522           support.  As of this writing the exact hardware interface is
1523           strongly in flux, so no good recommendation can be made.
1524
1525 config CRASH_DUMP
1526         bool "kernel crash dumps"
1527         depends on X86_64 || (X86_32 && HIGHMEM)
1528         ---help---
1529           Generate crash dump after being started by kexec.
1530           This should be normally only set in special crash dump kernels
1531           which are loaded in the main kernel with kexec-tools into
1532           a specially reserved region and then later executed after
1533           a crash by kdump/kexec. The crash dump kernel must be compiled
1534           to a memory address not used by the main kernel or BIOS using
1535           PHYSICAL_START, or it must be built as a relocatable image
1536           (CONFIG_RELOCATABLE=y).
1537           For more details see Documentation/kdump/kdump.txt
1538
1539 config KEXEC_JUMP
1540         bool "kexec jump (EXPERIMENTAL)"
1541         depends on EXPERIMENTAL
1542         depends on KEXEC && HIBERNATION
1543         ---help---
1544           Jump between original kernel and kexeced kernel and invoke
1545           code in physical address mode via KEXEC
1546
1547 config PHYSICAL_START
1548         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1549         default "0x1000000"
1550         ---help---
1551           This gives the physical address where the kernel is loaded.
1552
1553           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1554           bzImage will decompress itself to above physical address and
1555           run from there. Otherwise, bzImage will run from the address where
1556           it has been loaded by the boot loader and will ignore above physical
1557           address.
1558
1559           In normal kdump cases one does not have to set/change this option
1560           as now bzImage can be compiled as a completely relocatable image
1561           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1562           address. This option is mainly useful for the folks who don't want
1563           to use a bzImage for capturing the crash dump and want to use a
1564           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1565           to be specifically compiled to run from a specific memory area
1566           (normally a reserved region) and this option comes handy.
1567
1568           So if you are using bzImage for capturing the crash dump,
1569           leave the value here unchanged to 0x1000000 and set
1570           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1571           for capturing the crash dump change this value to start of
1572           the reserved region.  In other words, it can be set based on
1573           the "X" value as specified in the "crashkernel=YM@XM"
1574           command line boot parameter passed to the panic-ed
1575           kernel. Please take a look at Documentation/kdump/kdump.txt
1576           for more details about crash dumps.
1577
1578           Usage of bzImage for capturing the crash dump is recommended as
1579           one does not have to build two kernels. Same kernel can be used
1580           as production kernel and capture kernel. Above option should have
1581           gone away after relocatable bzImage support is introduced. But it
1582           is present because there are users out there who continue to use
1583           vmlinux for dump capture. This option should go away down the
1584           line.
1585
1586           Don't change this unless you know what you are doing.
1587
1588 config RELOCATABLE
1589         bool "Build a relocatable kernel"
1590         default y
1591         ---help---
1592           This builds a kernel image that retains relocation information
1593           so it can be loaded someplace besides the default 1MB.
1594           The relocations tend to make the kernel binary about 10% larger,
1595           but are discarded at runtime.
1596
1597           One use is for the kexec on panic case where the recovery kernel
1598           must live at a different physical address than the primary
1599           kernel.
1600
1601           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1602           it has been loaded at and the compile time physical address
1603           (CONFIG_PHYSICAL_START) is ignored.
1604
1605 # Relocation on x86-32 needs some additional build support
1606 config X86_NEED_RELOCS
1607         def_bool y
1608         depends on X86_32 && RELOCATABLE
1609
1610 config PHYSICAL_ALIGN
1611         hex "Alignment value to which kernel should be aligned" if X86_32
1612         default "0x1000000"
1613         range 0x2000 0x1000000
1614         ---help---
1615           This value puts the alignment restrictions on physical address
1616           where kernel is loaded and run from. Kernel is compiled for an
1617           address which meets above alignment restriction.
1618
1619           If bootloader loads the kernel at a non-aligned address and
1620           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1621           address aligned to above value and run from there.
1622
1623           If bootloader loads the kernel at a non-aligned address and
1624           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1625           load address and decompress itself to the address it has been
1626           compiled for and run from there. The address for which kernel is
1627           compiled already meets above alignment restrictions. Hence the
1628           end result is that kernel runs from a physical address meeting
1629           above alignment restrictions.
1630
1631           Don't change this unless you know what you are doing.
1632
1633 config HOTPLUG_CPU
1634         bool "Support for hot-pluggable CPUs"
1635         depends on SMP && HOTPLUG
1636         ---help---
1637           Say Y here to allow turning CPUs off and on. CPUs can be
1638           controlled through /sys/devices/system/cpu.
1639           ( Note: power management support will enable this option
1640             automatically on SMP systems. )
1641           Say N if you want to disable CPU hotplug.
1642
1643 config COMPAT_VDSO
1644         def_bool y
1645         prompt "Compat VDSO support"
1646         depends on X86_32 || IA32_EMULATION
1647         ---help---
1648           Map the 32-bit VDSO to the predictable old-style address too.
1649
1650           Say N here if you are running a sufficiently recent glibc
1651           version (2.3.3 or later), to remove the high-mapped
1652           VDSO mapping and to exclusively use the randomized VDSO.
1653
1654           If unsure, say Y.
1655
1656 config CMDLINE_BOOL
1657         bool "Built-in kernel command line"
1658         ---help---
1659           Allow for specifying boot arguments to the kernel at
1660           build time.  On some systems (e.g. embedded ones), it is
1661           necessary or convenient to provide some or all of the
1662           kernel boot arguments with the kernel itself (that is,
1663           to not rely on the boot loader to provide them.)
1664
1665           To compile command line arguments into the kernel,
1666           set this option to 'Y', then fill in the
1667           the boot arguments in CONFIG_CMDLINE.
1668
1669           Systems with fully functional boot loaders (i.e. non-embedded)
1670           should leave this option set to 'N'.
1671
1672 config CMDLINE
1673         string "Built-in kernel command string"
1674         depends on CMDLINE_BOOL
1675         default ""
1676         ---help---
1677           Enter arguments here that should be compiled into the kernel
1678           image and used at boot time.  If the boot loader provides a
1679           command line at boot time, it is appended to this string to
1680           form the full kernel command line, when the system boots.
1681
1682           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1683           change this behavior.
1684
1685           In most cases, the command line (whether built-in or provided
1686           by the boot loader) should specify the device for the root
1687           file system.
1688
1689 config CMDLINE_OVERRIDE
1690         bool "Built-in command line overrides boot loader arguments"
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 config USE_PERCPU_NUMA_NODE_ID
1714         def_bool X86_64
1715         depends on NUMA
1716
1717 menu "Power management and ACPI options"
1718
1719 config ARCH_HIBERNATION_HEADER
1720         def_bool y
1721         depends on X86_64 && HIBERNATION
1722
1723 source "kernel/power/Kconfig"
1724
1725 source "drivers/acpi/Kconfig"
1726
1727 source "drivers/sfi/Kconfig"
1728
1729 config X86_APM_BOOT
1730         def_bool y
1731         depends on APM || APM_MODULE
1732
1733 menuconfig APM
1734         tristate "APM (Advanced Power Management) BIOS support"
1735         depends on X86_32 && PM_SLEEP
1736         ---help---
1737           APM is a BIOS specification for saving power using several different
1738           techniques. This is mostly useful for battery powered laptops with
1739           APM compliant BIOSes. If you say Y here, the system time will be
1740           reset after a RESUME operation, the /proc/apm device will provide
1741           battery status information, and user-space programs will receive
1742           notification of APM "events" (e.g. battery status change).
1743
1744           If you select "Y" here, you can disable actual use of the APM
1745           BIOS by passing the "apm=off" option to the kernel at boot time.
1746
1747           Note that the APM support is almost completely disabled for
1748           machines with more than one CPU.
1749
1750           In order to use APM, you will need supporting software. For location
1751           and more information, read <file:Documentation/power/pm.txt> and the
1752           Battery Powered Linux mini-HOWTO, available from
1753           <http://www.tldp.org/docs.html#howto>.
1754
1755           This driver does not spin down disk drives (see the hdparm(8)
1756           manpage ("man 8 hdparm") for that), and it doesn't turn off
1757           VESA-compliant "green" monitors.
1758
1759           This driver does not support the TI 4000M TravelMate and the ACER
1760           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1761           desktop machines also don't have compliant BIOSes, and this driver
1762           may cause those machines to panic during the boot phase.
1763
1764           Generally, if you don't have a battery in your machine, there isn't
1765           much point in using this driver and you should say N. If you get
1766           random kernel OOPSes or reboots that don't seem to be related to
1767           anything, try disabling/enabling this option (or disabling/enabling
1768           APM in your BIOS).
1769
1770           Some other things you should try when experiencing seemingly random,
1771           "weird" problems:
1772
1773           1) make sure that you have enough swap space and that it is
1774           enabled.
1775           2) pass the "no-hlt" option to the kernel
1776           3) switch on floating point emulation in the kernel and pass
1777           the "no387" option to the kernel
1778           4) pass the "floppy=nodma" option to the kernel
1779           5) pass the "mem=4M" option to the kernel (thereby disabling
1780           all but the first 4 MB of RAM)
1781           6) make sure that the CPU is not over clocked.
1782           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1783           8) disable the cache from your BIOS settings
1784           9) install a fan for the video card or exchange video RAM
1785           10) install a better fan for the CPU
1786           11) exchange RAM chips
1787           12) exchange the motherboard.
1788
1789           To compile this driver as a module, choose M here: the
1790           module will be called apm.
1791
1792 if APM
1793
1794 config APM_IGNORE_USER_SUSPEND
1795         bool "Ignore USER SUSPEND"
1796         ---help---
1797           This option will ignore USER SUSPEND requests. On machines with a
1798           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1799           series notebooks, it is necessary to say Y because of a BIOS bug.
1800
1801 config APM_DO_ENABLE
1802         bool "Enable PM at boot time"
1803         ---help---
1804           Enable APM features at boot time. From page 36 of the APM BIOS
1805           specification: "When disabled, the APM BIOS does not automatically
1806           power manage devices, enter the Standby State, enter the Suspend
1807           State, or take power saving steps in response to CPU Idle calls."
1808           This driver will make CPU Idle calls when Linux is idle (unless this
1809           feature is turned off -- see "Do CPU IDLE calls", below). This
1810           should always save battery power, but more complicated APM features
1811           will be dependent on your BIOS implementation. You may need to turn
1812           this option off if your computer hangs at boot time when using APM
1813           support, or if it beeps continuously instead of suspending. Turn
1814           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1815           T400CDT. This is off by default since most machines do fine without
1816           this feature.
1817
1818 config APM_CPU_IDLE
1819         bool "Make CPU Idle calls when idle"
1820         ---help---
1821           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1822           On some machines, this can activate improved power savings, such as
1823           a slowed CPU clock rate, when the machine is idle. These idle calls
1824           are made after the idle loop has run for some length of time (e.g.,
1825           333 mS). On some machines, this will cause a hang at boot time or
1826           whenever the CPU becomes idle. (On machines with more than one CPU,
1827           this option does nothing.)
1828
1829 config APM_DISPLAY_BLANK
1830         bool "Enable console blanking using APM"
1831         ---help---
1832           Enable console blanking using the APM. Some laptops can use this to
1833           turn off the LCD backlight when the screen blanker of the Linux
1834           virtual console blanks the screen. Note that this is only used by
1835           the virtual console screen blanker, and won't turn off the backlight
1836           when using the X Window system. This also doesn't have anything to
1837           do with your VESA-compliant power-saving monitor. Further, this
1838           option doesn't work for all laptops -- it might not turn off your
1839           backlight at all, or it might print a lot of errors to the console,
1840           especially if you are using gpm.
1841
1842 config APM_ALLOW_INTS
1843         bool "Allow interrupts during APM BIOS calls"
1844         ---help---
1845           Normally we disable external interrupts while we are making calls to
1846           the APM BIOS as a measure to lessen the effects of a badly behaving
1847           BIOS implementation.  The BIOS should reenable interrupts if it
1848           needs to.  Unfortunately, some BIOSes do not -- especially those in
1849           many of the newer IBM Thinkpads.  If you experience hangs when you
1850           suspend, try setting this to Y.  Otherwise, say N.
1851
1852 endif # APM
1853
1854 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1855
1856 source "drivers/cpuidle/Kconfig"
1857
1858 source "drivers/idle/Kconfig"
1859
1860 endmenu
1861
1862
1863 menu "Bus options (PCI etc.)"
1864
1865 config PCI
1866         bool "PCI support"
1867         default y
1868         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1869         ---help---
1870           Find out whether you have a PCI motherboard. PCI is the name of a
1871           bus system, i.e. the way the CPU talks to the other stuff inside
1872           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1873           VESA. If you have PCI, say Y, otherwise N.
1874
1875 choice
1876         prompt "PCI access mode"
1877         depends on X86_32 && PCI
1878         default PCI_GOANY
1879         ---help---
1880           On PCI systems, the BIOS can be used to detect the PCI devices and
1881           determine their configuration. However, some old PCI motherboards
1882           have BIOS bugs and may crash if this is done. Also, some embedded
1883           PCI-based systems don't have any BIOS at all. Linux can also try to
1884           detect the PCI hardware directly without using the BIOS.
1885
1886           With this option, you can specify how Linux should detect the
1887           PCI devices. If you choose "BIOS", the BIOS will be used,
1888           if you choose "Direct", the BIOS won't be used, and if you
1889           choose "MMConfig", then PCI Express MMCONFIG will be used.
1890           If you choose "Any", the kernel will try MMCONFIG, then the
1891           direct access method and falls back to the BIOS if that doesn't
1892           work. If unsure, go with the default, which is "Any".
1893
1894 config PCI_GOBIOS
1895         bool "BIOS"
1896
1897 config PCI_GOMMCONFIG
1898         bool "MMConfig"
1899
1900 config PCI_GODIRECT
1901         bool "Direct"
1902
1903 config PCI_GOOLPC
1904         bool "OLPC"
1905         depends on OLPC
1906
1907 config PCI_GOANY
1908         bool "Any"
1909
1910 endchoice
1911
1912 config PCI_BIOS
1913         def_bool y
1914         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1915
1916 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1917 config PCI_DIRECT
1918         def_bool y
1919         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1920
1921 config PCI_MMCONFIG
1922         def_bool y
1923         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1924
1925 config PCI_OLPC
1926         def_bool y
1927         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1928
1929 config PCI_DOMAINS
1930         def_bool y
1931         depends on PCI
1932
1933 config PCI_MMCONFIG
1934         bool "Support mmconfig PCI config space access"
1935         depends on X86_64 && PCI && ACPI
1936
1937 config PCI_CNB20LE_QUIRK
1938         bool "Read CNB20LE Host Bridge Windows"
1939         depends on PCI
1940         help
1941           Read the PCI windows out of the CNB20LE host bridge. This allows
1942           PCI hotplug to work on systems with the CNB20LE chipset which do
1943           not have ACPI.
1944
1945 config DMAR
1946         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1947         depends on PCI_MSI && ACPI && EXPERIMENTAL
1948         help
1949           DMA remapping (DMAR) devices support enables independent address
1950           translations for Direct Memory Access (DMA) from devices.
1951           These DMA remapping devices are reported via ACPI tables
1952           and include PCI device scope covered by these DMA
1953           remapping devices.
1954
1955 config DMAR_DEFAULT_ON
1956         def_bool y
1957         prompt "Enable DMA Remapping Devices by default"
1958         depends on DMAR
1959         help
1960           Selecting this option will enable a DMAR device at boot time if
1961           one is found. If this option is not selected, DMAR support can
1962           be enabled by passing intel_iommu=on to the kernel. It is
1963           recommended you say N here while the DMAR code remains
1964           experimental.
1965
1966 config DMAR_BROKEN_GFX_WA
1967         bool "Workaround broken graphics drivers (going away soon)"
1968         depends on DMAR && BROKEN
1969         ---help---
1970           Current Graphics drivers tend to use physical address
1971           for DMA and avoid using DMA APIs. Setting this config
1972           option permits the IOMMU driver to set a unity map for
1973           all the OS-visible memory. Hence the driver can continue
1974           to use physical addresses for DMA, at least until this
1975           option is removed in the 2.6.32 kernel.
1976
1977 config DMAR_FLOPPY_WA
1978         def_bool y
1979         depends on DMAR
1980         ---help---
1981           Floppy disk drivers are known to bypass DMA API calls
1982           thereby failing to work when IOMMU is enabled. This
1983           workaround will setup a 1:1 mapping for the first
1984           16MiB to make floppy (an ISA device) work.
1985
1986 config INTR_REMAP
1987         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1988         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1989         ---help---
1990           Supports Interrupt remapping for IO-APIC and MSI devices.
1991           To use x2apic mode in the CPU's which support x2APIC enhancements or
1992           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1993
1994 source "drivers/pci/pcie/Kconfig"
1995
1996 source "drivers/pci/Kconfig"
1997
1998 # x86_64 have no ISA slots, but do have ISA-style DMA.
1999 config ISA_DMA_API
2000         def_bool y
2001
2002 if X86_32
2003
2004 config ISA
2005         bool "ISA support"
2006         ---help---
2007           Find out whether you have ISA slots on your motherboard.  ISA is the
2008           name of a bus system, i.e. the way the CPU talks to the other stuff
2009           inside your box.  Other bus systems are PCI, EISA, MicroChannel
2010           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2011           newer boards don't support it.  If you have ISA, say Y, otherwise N.
2012
2013 config EISA
2014         bool "EISA support"
2015         depends on ISA
2016         ---help---
2017           The Extended Industry Standard Architecture (EISA) bus was
2018           developed as an open alternative to the IBM MicroChannel bus.
2019
2020           The EISA bus provided some of the features of the IBM MicroChannel
2021           bus while maintaining backward compatibility with cards made for
2022           the older ISA bus.  The EISA bus saw limited use between 1988 and
2023           1995 when it was made obsolete by the PCI bus.
2024
2025           Say Y here if you are building a kernel for an EISA-based machine.
2026
2027           Otherwise, say N.
2028
2029 source "drivers/eisa/Kconfig"
2030
2031 config MCA
2032         bool "MCA support"
2033         ---help---
2034           MicroChannel Architecture is found in some IBM PS/2 machines and
2035           laptops.  It is a bus system similar to PCI or ISA. See
2036           <file:Documentation/mca.txt> (and especially the web page given
2037           there) before attempting to build an MCA bus kernel.
2038
2039 source "drivers/mca/Kconfig"
2040
2041 config SCx200
2042         tristate "NatSemi SCx200 support"
2043         ---help---
2044           This provides basic support for National Semiconductor's
2045           (now AMD's) Geode processors.  The driver probes for the
2046           PCI-IDs of several on-chip devices, so its a good dependency
2047           for other scx200_* drivers.
2048
2049           If compiled as a module, the driver is named scx200.
2050
2051 config SCx200HR_TIMER
2052         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2053         depends on SCx200
2054         default y
2055         ---help---
2056           This driver provides a clocksource built upon the on-chip
2057           27MHz high-resolution timer.  Its also a workaround for
2058           NSC Geode SC-1100's buggy TSC, which loses time when the
2059           processor goes idle (as is done by the scheduler).  The
2060           other workaround is idle=poll boot option.
2061
2062 config OLPC
2063         bool "One Laptop Per Child support"
2064         select GPIOLIB
2065         ---help---
2066           Add support for detecting the unique features of the OLPC
2067           XO hardware.
2068
2069 config OLPC_OPENFIRMWARE
2070         bool "Support for OLPC's Open Firmware"
2071         depends on !X86_64 && !X86_PAE
2072         default y if OLPC
2073         help
2074           This option adds support for the implementation of Open Firmware
2075           that is used on the OLPC XO-1 Children's Machine.
2076           If unsure, say N here.
2077
2078 endif # X86_32
2079
2080 config K8_NB
2081         def_bool y
2082         depends on CPU_SUP_AMD && PCI
2083
2084 source "drivers/pcmcia/Kconfig"
2085
2086 source "drivers/pci/hotplug/Kconfig"
2087
2088 endmenu
2089
2090
2091 menu "Executable file formats / Emulations"
2092
2093 source "fs/Kconfig.binfmt"
2094
2095 config IA32_EMULATION
2096         bool "IA32 Emulation"
2097         depends on X86_64
2098         select COMPAT_BINFMT_ELF
2099         ---help---
2100           Include code to run 32-bit programs under a 64-bit kernel. You should
2101           likely turn this on, unless you're 100% sure that you don't have any
2102           32-bit programs left.
2103
2104 config IA32_AOUT
2105         tristate "IA32 a.out support"
2106         depends on IA32_EMULATION
2107         ---help---
2108           Support old a.out binaries in the 32bit emulation.
2109
2110 config COMPAT
2111         def_bool y
2112         depends on IA32_EMULATION
2113
2114 config COMPAT_FOR_U64_ALIGNMENT
2115         def_bool COMPAT
2116         depends on X86_64
2117
2118 config SYSVIPC_COMPAT
2119         def_bool y
2120         depends on COMPAT && SYSVIPC
2121
2122 endmenu
2123
2124
2125 config HAVE_ATOMIC_IOMAP
2126         def_bool y
2127         depends on X86_32
2128
2129 source "net/Kconfig"
2130
2131 source "drivers/Kconfig"
2132
2133 source "drivers/firmware/Kconfig"
2134
2135 source "fs/Kconfig"
2136
2137 source "arch/x86/Kconfig.debug"
2138
2139 source "security/Kconfig"
2140
2141 source "crypto/Kconfig"
2142
2143 source "arch/x86/kvm/Kconfig"
2144
2145 source "lib/Kconfig"