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_IRQ_WORK
  29         select HAVE_IOREMAP_PROT
  30         select HAVE_KPROBES
  31         select ARCH_WANT_OPTIONAL_GPIOLIB
  32         select ARCH_WANT_FRAME_POINTERS
  33         select HAVE_DMA_ATTRS
  34         select HAVE_KRETPROBES
  35         select HAVE_OPTPROBES
  36         select HAVE_FTRACE_MCOUNT_RECORD
  37         select HAVE_C_RECORDMCOUNT
  38         select HAVE_DYNAMIC_FTRACE
  39         select HAVE_FUNCTION_TRACER
  40         select HAVE_FUNCTION_GRAPH_TRACER
  41         select HAVE_FUNCTION_GRAPH_FP_TEST
  42         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  43         select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  44         select HAVE_SYSCALL_TRACEPOINTS
  45         select HAVE_KVM
  46         select HAVE_ARCH_KGDB
  47         select HAVE_ARCH_TRACEHOOK
  48         select HAVE_GENERIC_DMA_COHERENT if X86_32
  49         select HAVE_EFFICIENT_UNALIGNED_ACCESS
  50         select USER_STACKTRACE_SUPPORT
  51         select HAVE_REGS_AND_STACK_ACCESS_API
  52         select HAVE_DMA_API_DEBUG
  53         select HAVE_KERNEL_GZIP
  54         select HAVE_KERNEL_BZIP2
  55         select HAVE_KERNEL_LZMA
  56         select HAVE_KERNEL_LZO
  57         select HAVE_HW_BREAKPOINT
  58         select HAVE_MIXED_BREAKPOINTS_REGS
  59         select PERF_EVENTS
  60         select HAVE_PERF_EVENTS_NMI
  61         select ANON_INODES
  62         select HAVE_ARCH_KMEMCHECK
  63         select HAVE_USER_RETURN_NOTIFIER
  64         select HAVE_ARCH_JUMP_LABEL
  65         select HAVE_TEXT_POKE_SMP
  66
  67 config INSTRUCTION_DECODER
  68         def_bool (KPROBES || PERF_EVENTS)
  69
  70 config OUTPUT_FORMAT
  71         string
  72         default "elf32-i386" if X86_32
  73         default "elf64-x86-64" if X86_64
  74
  75 config ARCH_DEFCONFIG
  76         string
  77         default "arch/x86/configs/i386_defconfig" if X86_32
  78         default "arch/x86/configs/x86_64_defconfig" if X86_64
  79
  80 config GENERIC_CMOS_UPDATE
  81         def_bool y
  82
  83 config CLOCKSOURCE_WATCHDOG
  84         def_bool y
  85
  86 config GENERIC_CLOCKEVENTS
  87         def_bool y
  88
  89 config GENERIC_CLOCKEVENTS_BROADCAST
  90         def_bool y
  91         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  92
  93 config LOCKDEP_SUPPORT
  94         def_bool y
  95
  96 config STACKTRACE_SUPPORT
  97         def_bool y
  98
  99 config HAVE_LATENCYTOP_SUPPORT
 100         def_bool y
 101
 102 config MMU
 103         def_bool y
 104
 105 config ZONE_DMA
 106         def_bool y
 107
 108 config SBUS
 109         bool
 110
 111 config NEED_DMA_MAP_STATE
 112        def_bool (X86_64 || DMAR || DMA_API_DEBUG)
 113
 114 config NEED_SG_DMA_LENGTH
 115         def_bool y
 116
 117 config GENERIC_ISA_DMA
 118         def_bool y
 119
 120 config GENERIC_IOMAP
 121         def_bool y
 122
 123 config GENERIC_BUG
 124         def_bool y
 125         depends on BUG
 126         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 127
 128 config GENERIC_BUG_RELATIVE_POINTERS
 129         bool
 130
 131 config GENERIC_HWEIGHT
 132         def_bool y
 133
 134 config GENERIC_GPIO
 135         bool
 136
 137 config ARCH_MAY_HAVE_PC_FDC
 138         def_bool y
 139
 140 config RWSEM_GENERIC_SPINLOCK
 141         def_bool !X86_XADD
 142
 143 config RWSEM_XCHGADD_ALGORITHM
 144         def_bool X86_XADD
 145
 146 config ARCH_HAS_CPU_IDLE_WAIT
 147         def_bool y
 148
 149 config GENERIC_CALIBRATE_DELAY
 150         def_bool y
 151
 152 config GENERIC_TIME_VSYSCALL
 153         bool
 154         default X86_64
 155
 156 config ARCH_HAS_CPU_RELAX
 157         def_bool y
 158
 159 config ARCH_HAS_DEFAULT_IDLE
 160         def_bool y
 161
 162 config ARCH_HAS_CACHE_LINE_SIZE
 163         def_bool y
 164
 165 config HAVE_SETUP_PER_CPU_AREA
 166         def_bool y
 167
 168 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 169         def_bool y
 170
 171 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 172         def_bool y
 173
 174 config HAVE_CPUMASK_OF_CPU_MAP
 175         def_bool X86_64_SMP
 176
 177 config ARCH_HIBERNATION_POSSIBLE
 178         def_bool y
 179
 180 config ARCH_SUSPEND_POSSIBLE
 181         def_bool y
 182
 183 config ZONE_DMA32
 184         bool
 185         default X86_64
 186
 187 config ARCH_POPULATES_NODE_MAP
 188         def_bool y
 189
 190 config AUDIT_ARCH
 191         bool
 192         default X86_64
 193
 194 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 195         def_bool y
 196
 197 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 198         def_bool y
 199
 200 config HAVE_EARLY_RES
 201         def_bool y
 202
 203 config HAVE_INTEL_TXT
 204         def_bool y
 205         depends on EXPERIMENTAL && DMAR && ACPI
 206
 207 # Use the generic interrupt handling code in kernel/irq/:
 208 config GENERIC_HARDIRQS
 209         def_bool y
 210
 211 config GENERIC_HARDIRQS_NO__DO_IRQ
 212        def_bool y
 213
 214 config GENERIC_IRQ_PROBE
 215         def_bool y
 216
 217 config GENERIC_PENDING_IRQ
 218         def_bool y
 219         depends on GENERIC_HARDIRQS && SMP
 220
 221 config USE_GENERIC_SMP_HELPERS
 222         def_bool y
 223         depends on SMP
 224
 225 config X86_32_SMP
 226         def_bool y
 227         depends on X86_32 && SMP
 228
 229 config X86_64_SMP
 230         def_bool y
 231         depends on X86_64 && SMP
 232
 233 config X86_HT
 234         def_bool y
 235         depends on SMP
 236
 237 config X86_TRAMPOLINE
 238         def_bool y
 239         depends on SMP || (64BIT && ACPI_SLEEP)
 240
 241 config X86_32_LAZY_GS
 242         def_bool y
 243         depends on X86_32 && !CC_STACKPROTECTOR
 244
 245 config ARCH_HWEIGHT_CFLAGS
 246         string
 247         default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
 248         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
 249
 250 config KTIME_SCALAR
 251         def_bool X86_32
 252
 253 config ARCH_CPU_PROBE_RELEASE
 254         def_bool y
 255         depends on HOTPLUG_CPU
 256
 257 source "init/Kconfig"
 258 source "kernel/Kconfig.freezer"
 259
 260 menu "Processor type and features"
 261
 262 source "kernel/time/Kconfig"
 263
 264 config SMP
 265         bool "Symmetric multi-processing support"
 266         ---help---
 267           This enables support for systems with more than one CPU. If you have
 268           a system with only one CPU, like most personal computers, say N. If
 269           you have a system with more than one CPU, say Y.
 270
 271           If you say N here, the kernel will run on single and multiprocessor
 272           machines, but will use only one CPU of a multiprocessor machine. If
 273           you say Y here, the kernel will run on many, but not all,
 274           singleprocessor machines. On a singleprocessor machine, the kernel
 275           will run faster if you say N here.
 276
 277           Note that if you say Y here and choose architecture "586" or
 278           "Pentium" under "Processor family", the kernel will not work on 486
 279           architectures. Similarly, multiprocessor kernels for the "PPro"
 280           architecture may not work on all Pentium based boards.
 281
 282           People using multiprocessor machines who say Y here should also say
 283           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 284           Management" code will be disabled if you say Y here.
 285
 286           See also <file:Documentation/i386/IO-APIC.txt>,
 287           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 288           <http://www.tldp.org/docs.html#howto>.
 289
 290           If you don't know what to do here, say N.
 291
 292 config X86_X2APIC
 293         bool "Support x2apic"
 294         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 295         ---help---
 296           This enables x2apic support on CPUs that have this feature.
 297
 298           This allows 32-bit apic IDs (so it can support very large systems),
 299           and accesses the local apic via MSRs not via mmio.
 300
 301           If you don't know what to do here, say N.
 302
 303 config SPARSE_IRQ
 304         bool "Support sparse irq numbering"
 305         depends on PCI_MSI || HT_IRQ
 306         ---help---
 307           This enables support for sparse irqs. This is useful for distro
 308           kernels that want to define a high CONFIG_NR_CPUS value but still
 309           want to have low kernel memory footprint on smaller machines.
 310
 311           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 312             out the irq_desc[] array in a more NUMA-friendly way. )
 313
 314           If you don't know what to do here, say N.
 315
 316 config NUMA_IRQ_DESC
 317         def_bool y
 318         depends on SPARSE_IRQ && NUMA
 319
 320 config X86_MPPARSE
 321         bool "Enable MPS table" if ACPI
 322         default y
 323         depends on X86_LOCAL_APIC
 324         ---help---
 325           For old smp systems that do not have proper acpi support. Newer systems
 326           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 327
 328 config X86_BIGSMP
 329         bool "Support for big SMP systems with more than 8 CPUs"
 330         depends on X86_32 && SMP
 331         ---help---
 332           This option is needed for the systems that have more than 8 CPUs
 333
 334 if X86_32
 335 config X86_EXTENDED_PLATFORM
 336         bool "Support for extended (non-PC) x86 platforms"
 337         default y
 338         ---help---
 339           If you disable this option then the kernel will only support
 340           standard PC platforms. (which covers the vast majority of
 341           systems out there.)
 342
 343           If you enable this option then you'll be able to select support
 344           for the following (non-PC) 32 bit x86 platforms:
 345                 AMD Elan
 346                 NUMAQ (IBM/Sequent)
 347                 RDC R-321x SoC
 348                 SGI 320/540 (Visual Workstation)
 349                 Summit/EXA (IBM x440)
 350                 Unisys ES7000 IA32 series
 351                 Moorestown MID devices
 352
 353           If you have one of these systems, or if you want to build a
 354           generic distribution kernel, say Y here - otherwise say N.
 355 endif
 356
 357 if X86_64
 358 config X86_EXTENDED_PLATFORM
 359         bool "Support for extended (non-PC) x86 platforms"
 360         default y
 361         ---help---
 362           If you disable this option then the kernel will only support
 363           standard PC platforms. (which covers the vast majority of
 364           systems out there.)
 365
 366           If you enable this option then you'll be able to select support
 367           for the following (non-PC) 64 bit x86 platforms:
 368                 ScaleMP vSMP
 369                 SGI Ultraviolet
 370
 371           If you have one of these systems, or if you want to build a
 372           generic distribution kernel, say Y here - otherwise say N.
 373 endif
 374 # This is an alphabetically sorted list of 64 bit extended platforms
 375 # Please maintain the alphabetic order if and when there are additions
 376
 377 config X86_VSMP
 378         bool "ScaleMP vSMP"
 379         select PARAVIRT
 380         depends on X86_64 && PCI
 381         depends on X86_EXTENDED_PLATFORM
 382         ---help---
 383           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 384           supposed to run on these EM64T-based machines.  Only choose this option
 385           if you have one of these machines.
 386
 387 config X86_UV
 388         bool "SGI Ultraviolet"
 389         depends on X86_64
 390         depends on X86_EXTENDED_PLATFORM
 391         depends on NUMA
 392         depends on X86_X2APIC
 393         ---help---
 394           This option is needed in order to support SGI Ultraviolet systems.
 395           If you don't have one of these, you should say N here.
 396
 397 # Following is an alphabetically sorted list of 32 bit extended platforms
 398 # Please maintain the alphabetic order if and when there are additions
 399
 400 config X86_ELAN
 401         bool "AMD Elan"
 402         depends on X86_32
 403         depends on X86_EXTENDED_PLATFORM
 404         ---help---
 405           Select this for an AMD Elan processor.
 406
 407           Do not use this option for K6/Athlon/Opteron processors!
 408
 409           If unsure, choose "PC-compatible" instead.
 410
 411 config X86_MRST
 412        bool "Moorestown MID platform"
 413         depends on PCI
 414         depends on PCI_GOANY
 415         depends on X86_32
 416         depends on X86_EXTENDED_PLATFORM
 417         depends on X86_IO_APIC
 418         select APB_TIMER
 419         ---help---
 420           Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 421           Internet Device(MID) platform. Moorestown consists of two chips:
 422           Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
 423           Unlike standard x86 PCs, Moorestown does not have many legacy devices
 424           nor standard legacy replacement devices/features. e.g. Moorestown does
 425           not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
 426
 427 config X86_RDC321X
 428         bool "RDC R-321x SoC"
 429         depends on X86_32
 430         depends on X86_EXTENDED_PLATFORM
 431         select M486
 432         select X86_REBOOTFIXUPS
 433         ---help---
 434           This option is needed for RDC R-321x system-on-chip, also known
 435           as R-8610-(G).
 436           If you don't have one of these chips, you should say N here.
 437
 438 config X86_32_NON_STANDARD
 439         bool "Support non-standard 32-bit SMP architectures"
 440         depends on X86_32 && SMP
 441         depends on X86_EXTENDED_PLATFORM
 442         ---help---
 443           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 444           subarchitectures.  It is intended for a generic binary kernel.
 445           if you select them all, kernel will probe it one by one. and will
 446           fallback to default.
 447
 448 # Alphabetically sorted list of Non standard 32 bit platforms
 449
 450 config X86_NUMAQ
 451         bool "NUMAQ (IBM/Sequent)"
 452         depends on X86_32_NON_STANDARD
 453         depends on PCI
 454         select NUMA
 455         select X86_MPPARSE
 456         ---help---
 457           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 458           NUMA multiquad box. This changes the way that processors are
 459           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 460           of Flat Logical.  You will need a new lynxer.elf file to flash your
 461           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 462
 463 config X86_SUPPORTS_MEMORY_FAILURE
 464         def_bool y
 465         # MCE code calls memory_failure():
 466         depends on X86_MCE
 467         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
 468         depends on !X86_NUMAQ
 469         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
 470         depends on X86_64 || !SPARSEMEM
 471         select ARCH_SUPPORTS_MEMORY_FAILURE
 472
 473 config X86_VISWS
 474         bool "SGI 320/540 (Visual Workstation)"
 475         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 476         depends on X86_32_NON_STANDARD
 477         ---help---
 478           The SGI Visual Workstation series is an IA32-based workstation
 479           based on SGI systems chips with some legacy PC hardware attached.
 480
 481           Say Y here to create a kernel to run on the SGI 320 or 540.
 482
 483           A kernel compiled for the Visual Workstation will run on general
 484           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 485
 486 config X86_SUMMIT
 487         bool "Summit/EXA (IBM x440)"
 488         depends on X86_32_NON_STANDARD
 489         ---help---
 490           This option is needed for IBM systems that use the Summit/EXA chipset.
 491           In particular, it is needed for the x440.
 492
 493 config X86_ES7000
 494         bool "Unisys ES7000 IA32 series"
 495         depends on X86_32_NON_STANDARD && X86_BIGSMP
 496         ---help---
 497           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 498           supposed to run on an IA32-based Unisys ES7000 system.
 499
 500 config SCHED_OMIT_FRAME_POINTER
 501         def_bool y
 502         prompt "Single-depth WCHAN output"
 503         depends on X86
 504         ---help---
 505           Calculate simpler /proc/<PID>/wchan values. If this option
 506           is disabled then wchan values will recurse back to the
 507           caller function. This provides more accurate wchan values,
 508           at the expense of slightly more scheduling overhead.
 509
 510           If in doubt, say "Y".
 511
 512 menuconfig PARAVIRT_GUEST
 513         bool "Paravirtualized guest support"
 514         ---help---
 515           Say Y here to get to see options related to running Linux under
 516           various hypervisors.  This option alone does not add any kernel code.
 517
 518           If you say N, all options in this submenu will be skipped and disabled.
 519
 520 if PARAVIRT_GUEST
 521
 522 source "arch/x86/xen/Kconfig"
 523
 524 config VMI
 525         bool "VMI Guest support (DEPRECATED)"
 526         select PARAVIRT
 527         depends on X86_32
 528         ---help---
 529           VMI provides a paravirtualized interface to the VMware ESX server
 530           (it could be used by other hypervisors in theory too, but is not
 531           at the moment), by linking the kernel to a GPL-ed ROM module
 532           provided by the hypervisor.
 533
 534           As of September 2009, VMware has started a phased retirement
 535           of this feature from VMware's products. Please see
 536           feature-removal-schedule.txt for details.  If you are
 537           planning to enable this option, please note that you cannot
 538           live migrate a VMI enabled VM to a future VMware product,
 539           which doesn't support VMI. So if you expect your kernel to
 540           seamlessly migrate to newer VMware products, keep this
 541           disabled.
 542
 543 config KVM_CLOCK
 544         bool "KVM paravirtualized clock"
 545         select PARAVIRT
 546         select PARAVIRT_CLOCK
 547         ---help---
 548           Turning on this option will allow you to run a paravirtualized clock
 549           when running over the KVM hypervisor. Instead of relying on a PIT
 550           (or probably other) emulation by the underlying device model, the host
 551           provides the guest with timing infrastructure such as time of day, and
 552           system time
 553
 554 config KVM_GUEST
 555         bool "KVM Guest support"
 556         select PARAVIRT
 557         ---help---
 558           This option enables various optimizations for running under the KVM
 559           hypervisor.
 560
 561 source "arch/x86/lguest/Kconfig"
 562
 563 config PARAVIRT
 564         bool "Enable paravirtualization code"
 565         ---help---
 566           This changes the kernel so it can modify itself when it is run
 567           under a hypervisor, potentially improving performance significantly
 568           over full virtualization.  However, when run without a hypervisor
 569           the kernel is theoretically slower and slightly larger.
 570
 571 config PARAVIRT_SPINLOCKS
 572         bool "Paravirtualization layer for spinlocks"
 573         depends on PARAVIRT && SMP && EXPERIMENTAL
 574         ---help---
 575           Paravirtualized spinlocks allow a pvops backend to replace the
 576           spinlock implementation with something virtualization-friendly
 577           (for example, block the virtual CPU rather than spinning).
 578
 579           Unfortunately the downside is an up to 5% performance hit on
 580           native kernels, with various workloads.
 581
 582           If you are unsure how to answer this question, answer N.
 583
 584 config PARAVIRT_CLOCK
 585         bool
 586
 587 endif
 588
 589 config PARAVIRT_DEBUG
 590         bool "paravirt-ops debugging"
 591         depends on PARAVIRT && DEBUG_KERNEL
 592         ---help---
 593           Enable to debug paravirt_ops internals.  Specifically, BUG if
 594           a paravirt_op is missing when it is called.
 595
 596 config NO_BOOTMEM
 597         default y
 598         bool "Disable Bootmem code"
 599         ---help---
 600           Use early_res directly instead of bootmem before slab is ready.
 601                 - allocator (buddy) [generic]
 602                 - early allocator (bootmem) [generic]
 603                 - very early allocator (reserve_early*()) [x86]
 604                 - very very early allocator (early brk model) [x86]
 605           So reduce one layer between early allocator to final allocator
 606
 607
 608 config MEMTEST
 609         bool "Memtest"
 610         ---help---
 611           This option adds a kernel parameter 'memtest', which allows memtest
 612           to be set.
 613                 memtest=0, mean disabled; -- default
 614                 memtest=1, mean do 1 test pattern;
 615                 ...
 616                 memtest=4, mean do 4 test patterns.
 617           If you are unsure how to answer this question, answer N.
 618
 619 config X86_SUMMIT_NUMA
 620         def_bool y
 621         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 622
 623 config X86_CYCLONE_TIMER
 624         def_bool y
 625         depends on X86_32_NON_STANDARD
 626
 627 source "arch/x86/Kconfig.cpu"
 628
 629 config HPET_TIMER
 630         def_bool X86_64
 631         prompt "HPET Timer Support" if X86_32
 632         ---help---
 633           Use the IA-PC HPET (High Precision Event Timer) to manage
 634           time in preference to the PIT and RTC, if a HPET is
 635           present.
 636           HPET is the next generation timer replacing legacy 8254s.
 637           The HPET provides a stable time base on SMP
 638           systems, unlike the TSC, but it is more expensive to access,
 639           as it is off-chip.  You can find the HPET spec at
 640           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 641
 642           You can safely choose Y here.  However, HPET will only be
 643           activated if the platform and the BIOS support this feature.
 644           Otherwise the 8254 will be used for timing services.
 645
 646           Choose N to continue using the legacy 8254 timer.
 647
 648 config HPET_EMULATE_RTC
 649         def_bool y
 650         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 651
 652 config APB_TIMER
 653        def_bool y if MRST
 654        prompt "Langwell APB Timer Support" if X86_MRST
 655        help
 656          APB timer is the replacement for 8254, HPET on X86 MID platforms.
 657          The APBT provides a stable time base on SMP
 658          systems, unlike the TSC, but it is more expensive to access,
 659          as it is off-chip. APB timers are always running regardless of CPU
 660          C states, they are used as per CPU clockevent device when possible.
 661
 662 # Mark as embedded because too many people got it wrong.
 663 # The code disables itself when not needed.
 664 config DMI
 665         default y
 666         bool "Enable DMI scanning" if EMBEDDED
 667         ---help---
 668           Enabled scanning of DMI to identify machine quirks. Say Y
 669           here unless you have verified that your setup is not
 670           affected by entries in the DMI blacklist. Required by PNP
 671           BIOS code.
 672
 673 config GART_IOMMU
 674         bool "GART IOMMU support" if EMBEDDED
 675         default y
 676         select SWIOTLB
 677         depends on X86_64 && PCI && AMD_NB
 678         ---help---
 679           Support for full DMA access of devices with 32bit memory access only
 680           on systems with more than 3GB. This is usually needed for USB,
 681           sound, many IDE/SATA chipsets and some other devices.
 682           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 683           based hardware IOMMU and a software bounce buffer based IOMMU used
 684           on Intel systems and as fallback.
 685           The code is only active when needed (enough memory and limited
 686           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 687           too.
 688
 689 config CALGARY_IOMMU
 690         bool "IBM Calgary IOMMU support"
 691         select SWIOTLB
 692         depends on X86_64 && PCI && EXPERIMENTAL
 693         ---help---
 694           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 695           systems. Needed to run systems with more than 3GB of memory
 696           properly with 32-bit PCI devices that do not support DAC
 697           (Double Address Cycle). Calgary also supports bus level
 698           isolation, where all DMAs pass through the IOMMU.  This
 699           prevents them from going anywhere except their intended
 700           destination. This catches hard-to-find kernel bugs and
 701           mis-behaving drivers and devices that do not use the DMA-API
 702           properly to set up their DMA buffers.  The IOMMU can be
 703           turned off at boot time with the iommu=off parameter.
 704           Normally the kernel will make the right choice by itself.
 705           If unsure, say Y.
 706
 707 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 708         def_bool y
 709         prompt "Should Calgary be enabled by default?"
 710         depends on CALGARY_IOMMU
 711         ---help---
 712           Should Calgary be enabled by default? if you choose 'y', Calgary
 713           will be used (if it exists). If you choose 'n', Calgary will not be
 714           used even if it exists. If you choose 'n' and would like to use
 715           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 716           If unsure, say Y.
 717
 718 config AMD_IOMMU
 719         bool "AMD IOMMU support"
 720         select SWIOTLB
 721         select PCI_MSI
 722         depends on X86_64 && PCI && ACPI
 723         ---help---
 724           With this option you can enable support for AMD IOMMU hardware in
 725           your system. An IOMMU is a hardware component which provides
 726           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 727           can isolate the the DMA memory of different devices and protect the
 728           system from misbehaving device drivers or hardware.
 729
 730           You can find out if your system has an AMD IOMMU if you look into
 731           your BIOS for an option to enable it or if you have an IVRS ACPI
 732           table.
 733
 734 config AMD_IOMMU_STATS
 735         bool "Export AMD IOMMU statistics to debugfs"
 736         depends on AMD_IOMMU
 737         select DEBUG_FS
 738         ---help---
 739           This option enables code in the AMD IOMMU driver to collect various
 740           statistics about whats happening in the driver and exports that
 741           information to userspace via debugfs.
 742           If unsure, say N.
 743
 744 # need this always selected by IOMMU for the VIA workaround
 745 config SWIOTLB
 746         def_bool y if X86_64
 747         ---help---
 748           Support for software bounce buffers used on x86-64 systems
 749           which don't have a hardware IOMMU (e.g. the current generation
 750           of Intel's x86-64 CPUs). Using this PCI devices which can only
 751           access 32-bits of memory can be used on systems with more than
 752           3 GB of memory. If unsure, say Y.
 753
 754 config IOMMU_HELPER
 755         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 756
 757 config IOMMU_API
 758         def_bool (AMD_IOMMU || DMAR)
 759
 760 config MAXSMP
 761         bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 762         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 763         select CPUMASK_OFFSTACK
 764         ---help---
 765           Enable maximum number of CPUS and NUMA Nodes for this architecture.
 766           If unsure, say N.
 767
 768 config NR_CPUS
 769         int "Maximum number of CPUs" if SMP && !MAXSMP
 770         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 771         range 2 512 if SMP && !MAXSMP
 772         default "1" if !SMP
 773         default "4096" if MAXSMP
 774         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 775         default "8" if SMP
 776         ---help---
 777           This allows you to specify the maximum number of CPUs which this
 778           kernel will support.  The maximum supported value is 512 and the
 779           minimum value which makes sense is 2.
 780
 781           This is purely to save memory - each supported CPU adds
 782           approximately eight kilobytes to the kernel image.
 783
 784 config SCHED_SMT
 785         bool "SMT (Hyperthreading) scheduler support"
 786         depends on X86_HT
 787         ---help---
 788           SMT scheduler support improves the CPU scheduler's decision making
 789           when dealing with Intel Pentium 4 chips with HyperThreading at a
 790           cost of slightly increased overhead in some places. If unsure say
 791           N here.
 792
 793 config SCHED_MC
 794         def_bool y
 795         prompt "Multi-core scheduler support"
 796         depends on X86_HT
 797         ---help---
 798           Multi-core scheduler support improves the CPU scheduler's decision
 799           making when dealing with multi-core CPU chips at a cost of slightly
 800           increased overhead in some places. If unsure say N here.
 801
 802 config IRQ_TIME_ACCOUNTING
 803         bool "Fine granularity task level IRQ time accounting"
 804         default n
 805         ---help---
 806           Select this option to enable fine granularity task irq time
 807           accounting. This is done by reading a timestamp on each
 808           transitions between softirq and hardirq state, so there can be a
 809           small performance impact.
 810
 811           If in doubt, say N here.
 812
 813 source "kernel/Kconfig.preempt"
 814
 815 config X86_UP_APIC
 816         bool "Local APIC support on uniprocessors"
 817         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 818         ---help---
 819           A local APIC (Advanced Programmable Interrupt Controller) is an
 820           integrated interrupt controller in the CPU. If you have a single-CPU
 821           system which has a processor with a local APIC, you can say Y here to
 822           enable and use it. If you say Y here even though your machine doesn't
 823           have a local APIC, then the kernel will still run with no slowdown at
 824           all. The local APIC supports CPU-generated self-interrupts (timer,
 825           performance counters), and the NMI watchdog which detects hard
 826           lockups.
 827
 828 config X86_UP_IOAPIC
 829         bool "IO-APIC support on uniprocessors"
 830         depends on X86_UP_APIC
 831         ---help---
 832           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 833           SMP-capable replacement for PC-style interrupt controllers. Most
 834           SMP systems and many recent uniprocessor systems have one.
 835
 836           If you have a single-CPU system with an IO-APIC, you can say Y here
 837           to use it. If you say Y here even though your machine doesn't have
 838           an IO-APIC, then the kernel will still run with no slowdown at all.
 839
 840 config X86_LOCAL_APIC
 841         def_bool y
 842         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 843
 844 config X86_IO_APIC
 845         def_bool y
 846         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 847
 848 config X86_VISWS_APIC
 849         def_bool y
 850         depends on X86_32 && X86_VISWS
 851
 852 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 853         bool "Reroute for broken boot IRQs"
 854         depends on X86_IO_APIC
 855         ---help---
 856           This option enables a workaround that fixes a source of
 857           spurious interrupts. This is recommended when threaded
 858           interrupt handling is used on systems where the generation of
 859           superfluous "boot interrupts" cannot be disabled.
 860
 861           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 862           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 863           kernel does during interrupt handling). On chipsets where this
 864           boot IRQ generation cannot be disabled, this workaround keeps
 865           the original IRQ line masked so that only the equivalent "boot
 866           IRQ" is delivered to the CPUs. The workaround also tells the
 867           kernel to set up the IRQ handler on the boot IRQ line. In this
 868           way only one interrupt is delivered to the kernel. Otherwise
 869           the spurious second interrupt may cause the kernel to bring
 870           down (vital) interrupt lines.
 871
 872           Only affects "broken" chipsets. Interrupt sharing may be
 873           increased on these systems.
 874
 875 config X86_MCE
 876         bool "Machine Check / overheating reporting"
 877         ---help---
 878           Machine Check support allows the processor to notify the
 879           kernel if it detects a problem (e.g. overheating, data corruption).
 880           The action the kernel takes depends on the severity of the problem,
 881           ranging from warning messages to halting the machine.
 882
 883 config X86_MCE_INTEL
 884         def_bool y
 885         prompt "Intel MCE features"
 886         depends on X86_MCE && X86_LOCAL_APIC
 887         ---help---
 888            Additional support for intel specific MCE features such as
 889            the thermal monitor.
 890
 891 config X86_MCE_AMD
 892         def_bool y
 893         prompt "AMD MCE features"
 894         depends on X86_MCE && X86_LOCAL_APIC
 895         ---help---
 896            Additional support for AMD specific MCE features such as
 897            the DRAM Error Threshold.
 898
 899 config X86_ANCIENT_MCE
 900         bool "Support for old Pentium 5 / WinChip machine checks"
 901         depends on X86_32 && X86_MCE
 902         ---help---
 903           Include support for machine check handling on old Pentium 5 or WinChip
 904           systems. These typically need to be enabled explicitely on the command
 905           line.
 906
 907 config X86_MCE_THRESHOLD
 908         depends on X86_MCE_AMD || X86_MCE_INTEL
 909         def_bool y
 910
 911 config X86_MCE_INJECT
 912         depends on X86_MCE
 913         tristate "Machine check injector support"
 914         ---help---
 915           Provide support for injecting machine checks for testing purposes.
 916           If you don't know what a machine check is and you don't do kernel
 917           QA it is safe to say n.
 918
 919 config X86_THERMAL_VECTOR
 920         def_bool y
 921         depends on X86_MCE_INTEL
 922
 923 config VM86
 924         bool "Enable VM86 support" if EMBEDDED
 925         default y
 926         depends on X86_32
 927         ---help---
 928           This option is required by programs like DOSEMU to run 16-bit legacy
 929           code on X86 processors. It also may be needed by software like
 930           XFree86 to initialize some video cards via BIOS. Disabling this
 931           option saves about 6k.
 932
 933 config TOSHIBA
 934         tristate "Toshiba Laptop support"
 935         depends on X86_32
 936         ---help---
 937           This adds a driver to safely access the System Management Mode of
 938           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 939           not work on models with a Phoenix BIOS. The System Management Mode
 940           is used to set the BIOS and power saving options on Toshiba portables.
 941
 942           For information on utilities to make use of this driver see the
 943           Toshiba Linux utilities web site at:
 944           <http://www.buzzard.org.uk/toshiba/>.
 945
 946           Say Y if you intend to run this kernel on a Toshiba portable.
 947           Say N otherwise.
 948
 949 config I8K
 950         tristate "Dell laptop support"
 951         ---help---
 952           This adds a driver to safely access the System Management Mode
 953           of the CPU on the Dell Inspiron 8000. The System Management Mode
 954           is used to read cpu temperature and cooling fan status and to
 955           control the fans on the I8K portables.
 956
 957           This driver has been tested only on the Inspiron 8000 but it may
 958           also work with other Dell laptops. You can force loading on other
 959           models by passing the parameter `force=1' to the module. Use at
 960           your own risk.
 961
 962           For information on utilities to make use of this driver see the
 963           I8K Linux utilities web site at:
 964           <http://people.debian.org/~dz/i8k/>
 965
 966           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 967           Say N otherwise.
 968
 969 config X86_REBOOTFIXUPS
 970         bool "Enable X86 board specific fixups for reboot"
 971         depends on X86_32
 972         ---help---
 973           This enables chipset and/or board specific fixups to be done
 974           in order to get reboot to work correctly. This is only needed on
 975           some combinations of hardware and BIOS. The symptom, for which
 976           this config is intended, is when reboot ends with a stalled/hung
 977           system.
 978
 979           Currently, the only fixup is for the Geode machines using
 980           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 981
 982           Say Y if you want to enable the fixup. Currently, it's safe to
 983           enable this option even if you don't need it.
 984           Say N otherwise.
 985
 986 config MICROCODE
 987         tristate "/dev/cpu/microcode - microcode support"
 988         select FW_LOADER
 989         ---help---
 990           If you say Y here, you will be able to update the microcode on
 991           certain Intel and AMD processors. The Intel support is for the
 992           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 993           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 994           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 995           You will obviously need the actual microcode binary data itself
 996           which is not shipped with the Linux kernel.
 997
 998           This option selects the general module only, you need to select
 999           at least one vendor specific module as well.
1000
1001           To compile this driver as a module, choose M here: the
1002           module will be called microcode.
1003
1004 config MICROCODE_INTEL
1005         bool "Intel microcode patch loading support"
1006         depends on MICROCODE
1007         default MICROCODE
1008         select FW_LOADER
1009         ---help---
1010           This options enables microcode patch loading support for Intel
1011           processors.
1012
1013           For latest news and information on obtaining all the required
1014           Intel ingredients for this driver, check:
1015           <http://www.urbanmyth.org/microcode/>.
1016
1017 config MICROCODE_AMD
1018         bool "AMD microcode patch loading support"
1019         depends on MICROCODE
1020         select FW_LOADER
1021         ---help---
1022           If you select this option, microcode patch loading support for AMD
1023           processors will be enabled.
1024
1025 config MICROCODE_OLD_INTERFACE
1026         def_bool y
1027         depends on MICROCODE
1028
1029 config X86_MSR
1030         tristate "/dev/cpu/*/msr - Model-specific register support"
1031         ---help---
1032           This device gives privileged processes access to the x86
1033           Model-Specific Registers (MSRs).  It is a character device with
1034           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1035           MSR accesses are directed to a specific CPU on multi-processor
1036           systems.
1037
1038 config X86_CPUID
1039         tristate "/dev/cpu/*/cpuid - CPU information support"
1040         ---help---
1041           This device gives processes access to the x86 CPUID instruction to
1042           be executed on a specific processor.  It is a character device
1043           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1044           /dev/cpu/31/cpuid.
1045
1046 choice
1047         prompt "High Memory Support"
1048         default HIGHMEM64G if X86_NUMAQ
1049         default HIGHMEM4G
1050         depends on X86_32
1051
1052 config NOHIGHMEM
1053         bool "off"
1054         depends on !X86_NUMAQ
1055         ---help---
1056           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1057           However, the address space of 32-bit x86 processors is only 4
1058           Gigabytes large. That means that, if you have a large amount of
1059           physical memory, not all of it can be "permanently mapped" by the
1060           kernel. The physical memory that's not permanently mapped is called
1061           "high memory".
1062
1063           If you are compiling a kernel which will never run on a machine with
1064           more than 1 Gigabyte total physical RAM, answer "off" here (default
1065           choice and suitable for most users). This will result in a "3GB/1GB"
1066           split: 3GB are mapped so that each process sees a 3GB virtual memory
1067           space and the remaining part of the 4GB virtual memory space is used
1068           by the kernel to permanently map as much physical memory as
1069           possible.
1070
1071           If the machine has between 1 and 4 Gigabytes physical RAM, then
1072           answer "4GB" here.
1073
1074           If more than 4 Gigabytes is used then answer "64GB" here. This
1075           selection turns Intel PAE (Physical Address Extension) mode on.
1076           PAE implements 3-level paging on IA32 processors. PAE is fully
1077           supported by Linux, PAE mode is implemented on all recent Intel
1078           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1079           then the kernel will not boot on CPUs that don't support PAE!
1080
1081           The actual amount of total physical memory will either be
1082           auto detected or can be forced by using a kernel command line option
1083           such as "mem=256M". (Try "man bootparam" or see the documentation of
1084           your boot loader (lilo or loadlin) about how to pass options to the
1085           kernel at boot time.)
1086
1087           If unsure, say "off".
1088
1089 config HIGHMEM4G
1090         bool "4GB"
1091         depends on !X86_NUMAQ
1092         ---help---
1093           Select this if you have a 32-bit processor and between 1 and 4
1094           gigabytes of physical RAM.
1095
1096 config HIGHMEM64G
1097         bool "64GB"
1098         depends on !M386 && !M486
1099         select X86_PAE
1100         ---help---
1101           Select this if you have a 32-bit processor and more than 4
1102           gigabytes of physical RAM.
1103
1104 endchoice
1105
1106 choice
1107         depends on EXPERIMENTAL
1108         prompt "Memory split" if EMBEDDED
1109         default VMSPLIT_3G
1110         depends on X86_32
1111         ---help---
1112           Select the desired split between kernel and user memory.
1113
1114           If the address range available to the kernel is less than the
1115           physical memory installed, the remaining memory will be available
1116           as "high memory". Accessing high memory is a little more costly
1117           than low memory, as it needs to be mapped into the kernel first.
1118           Note that increasing the kernel address space limits the range
1119           available to user programs, making the address space there
1120           tighter.  Selecting anything other than the default 3G/1G split
1121           will also likely make your kernel incompatible with binary-only
1122           kernel modules.
1123
1124           If you are not absolutely sure what you are doing, leave this
1125           option alone!
1126
1127         config VMSPLIT_3G
1128                 bool "3G/1G user/kernel split"
1129         config VMSPLIT_3G_OPT
1130                 depends on !X86_PAE
1131                 bool "3G/1G user/kernel split (for full 1G low memory)"
1132         config VMSPLIT_2G
1133                 bool "2G/2G user/kernel split"
1134         config VMSPLIT_2G_OPT
1135                 depends on !X86_PAE
1136                 bool "2G/2G user/kernel split (for full 2G low memory)"
1137         config VMSPLIT_1G
1138                 bool "1G/3G user/kernel split"
1139 endchoice
1140
1141 config PAGE_OFFSET
1142         hex
1143         default 0xB0000000 if VMSPLIT_3G_OPT
1144         default 0x80000000 if VMSPLIT_2G
1145         default 0x78000000 if VMSPLIT_2G_OPT
1146         default 0x40000000 if VMSPLIT_1G
1147         default 0xC0000000
1148         depends on X86_32
1149
1150 config HIGHMEM
1151         def_bool y
1152         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1153
1154 config X86_PAE
1155         bool "PAE (Physical Address Extension) Support"
1156         depends on X86_32 && !HIGHMEM4G
1157         ---help---
1158           PAE is required for NX support, and furthermore enables
1159           larger swapspace support for non-overcommit purposes. It
1160           has the cost of more pagetable lookup overhead, and also
1161           consumes more pagetable space per process.
1162
1163 config ARCH_PHYS_ADDR_T_64BIT
1164         def_bool X86_64 || X86_PAE
1165
1166 config DIRECT_GBPAGES
1167         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1168         default y
1169         depends on X86_64
1170         ---help---
1171           Allow the kernel linear mapping to use 1GB pages on CPUs that
1172           support it. This can improve the kernel's performance a tiny bit by
1173           reducing TLB pressure. If in doubt, say "Y".
1174
1175 # Common NUMA Features
1176 config NUMA
1177         bool "Numa Memory Allocation and Scheduler Support"
1178         depends on SMP
1179         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1180         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1181         ---help---
1182           Enable NUMA (Non Uniform Memory Access) support.
1183
1184           The kernel will try to allocate memory used by a CPU on the
1185           local memory controller of the CPU and add some more
1186           NUMA awareness to the kernel.
1187
1188           For 64-bit this is recommended if the system is Intel Core i7
1189           (or later), AMD Opteron, or EM64T NUMA.
1190
1191           For 32-bit this is only needed on (rare) 32-bit-only platforms
1192           that support NUMA topologies, such as NUMAQ / Summit, or if you
1193           boot a 32-bit kernel on a 64-bit NUMA platform.
1194
1195           Otherwise, you should say N.
1196
1197 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1198         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1199
1200 config K8_NUMA
1201         def_bool y
1202         prompt "Old style AMD Opteron NUMA detection"
1203         depends on X86_64 && NUMA && PCI
1204         ---help---
1205           Enable K8 NUMA node topology detection.  You should say Y here if
1206           you have a multi processor AMD K8 system. This uses an old
1207           method to read the NUMA configuration directly from the builtin
1208           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1209           instead, which also takes priority if both are compiled in.
1210
1211 config X86_64_ACPI_NUMA
1212         def_bool y
1213         prompt "ACPI NUMA detection"
1214         depends on X86_64 && NUMA && ACPI && PCI
1215         select ACPI_NUMA
1216         ---help---
1217           Enable ACPI SRAT based node topology detection.
1218
1219 # Some NUMA nodes have memory ranges that span
1220 # other nodes.  Even though a pfn is valid and
1221 # between a node's start and end pfns, it may not
1222 # reside on that node.  See memmap_init_zone()
1223 # for details.
1224 config NODES_SPAN_OTHER_NODES
1225         def_bool y
1226         depends on X86_64_ACPI_NUMA
1227
1228 config NUMA_EMU
1229         bool "NUMA emulation"
1230         depends on X86_64 && NUMA
1231         ---help---
1232           Enable NUMA emulation. A flat machine will be split
1233           into virtual nodes when booted with "numa=fake=N", where N is the
1234           number of nodes. This is only useful for debugging.
1235
1236 config NODES_SHIFT
1237         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1238         range 1 10
1239         default "10" if MAXSMP
1240         default "6" if X86_64
1241         default "4" if X86_NUMAQ
1242         default "3"
1243         depends on NEED_MULTIPLE_NODES
1244         ---help---
1245           Specify the maximum number of NUMA Nodes available on the target
1246           system.  Increases memory reserved to accommodate various tables.
1247
1248 config HAVE_ARCH_BOOTMEM
1249         def_bool y
1250         depends on X86_32 && NUMA
1251
1252 config ARCH_HAVE_MEMORY_PRESENT
1253         def_bool y
1254         depends on X86_32 && DISCONTIGMEM
1255
1256 config NEED_NODE_MEMMAP_SIZE
1257         def_bool y
1258         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1259
1260 config HAVE_ARCH_ALLOC_REMAP
1261         def_bool y
1262         depends on X86_32 && NUMA
1263
1264 config ARCH_FLATMEM_ENABLE
1265         def_bool y
1266         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1267
1268 config ARCH_DISCONTIGMEM_ENABLE
1269         def_bool y
1270         depends on NUMA && X86_32
1271
1272 config ARCH_DISCONTIGMEM_DEFAULT
1273         def_bool y
1274         depends on NUMA && X86_32
1275
1276 config ARCH_PROC_KCORE_TEXT
1277         def_bool y
1278         depends on X86_64 && PROC_KCORE
1279
1280 config ARCH_SPARSEMEM_DEFAULT
1281         def_bool y
1282         depends on X86_64
1283
1284 config ARCH_SPARSEMEM_ENABLE
1285         def_bool y
1286         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1287         select SPARSEMEM_STATIC if X86_32
1288         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1289
1290 config ARCH_SELECT_MEMORY_MODEL
1291         def_bool y
1292         depends on ARCH_SPARSEMEM_ENABLE
1293
1294 config ARCH_MEMORY_PROBE
1295         def_bool X86_64
1296         depends on MEMORY_HOTPLUG
1297
1298 config ILLEGAL_POINTER_VALUE
1299        hex
1300        default 0 if X86_32
1301        default 0xdead000000000000 if X86_64
1302
1303 source "mm/Kconfig"
1304
1305 config HIGHPTE
1306         bool "Allocate 3rd-level pagetables from highmem"
1307         depends on HIGHMEM
1308         ---help---
1309           The VM uses one page table entry for each page of physical memory.
1310           For systems with a lot of RAM, this can be wasteful of precious
1311           low memory.  Setting this option will put user-space page table
1312           entries in high memory.
1313
1314 config X86_CHECK_BIOS_CORRUPTION
1315         bool "Check for low memory corruption"
1316         ---help---
1317           Periodically check for memory corruption in low memory, which
1318           is suspected to be caused by BIOS.  Even when enabled in the
1319           configuration, it is disabled at runtime.  Enable it by
1320           setting "memory_corruption_check=1" on the kernel command
1321           line.  By default it scans the low 64k of memory every 60
1322           seconds; see the memory_corruption_check_size and
1323           memory_corruption_check_period parameters in
1324           Documentation/kernel-parameters.txt to adjust this.
1325
1326           When enabled with the default parameters, this option has
1327           almost no overhead, as it reserves a relatively small amount
1328           of memory and scans it infrequently.  It both detects corruption
1329           and prevents it from affecting the running system.
1330
1331           It is, however, intended as a diagnostic tool; if repeatable
1332           BIOS-originated corruption always affects the same memory,
1333           you can use memmap= to prevent the kernel from using that
1334           memory.
1335
1336 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1337         bool "Set the default setting of memory_corruption_check"
1338         depends on X86_CHECK_BIOS_CORRUPTION
1339         default y
1340         ---help---
1341           Set whether the default state of memory_corruption_check is
1342           on or off.
1343
1344 config X86_RESERVE_LOW
1345         int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1346         default 64
1347         range 4 640
1348         ---help---
1349           Specify the amount of low memory to reserve for the BIOS.
1350
1351           The first page contains BIOS data structures that the kernel
1352           must not use, so that page must always be reserved.
1353
1354           By default we reserve the first 64K of physical RAM, as a
1355           number of BIOSes are known to corrupt that memory range
1356           during events such as suspend/resume or monitor cable
1357           insertion, so it must not be used by the kernel.
1358
1359           You can set this to 4 if you are absolutely sure that you
1360           trust the BIOS to get all its memory reservations and usages
1361           right.  If you know your BIOS have problems beyond the
1362           default 64K area, you can set this to 640 to avoid using the
1363           entire low memory range.
1364
1365           If you have doubts about the BIOS (e.g. suspend/resume does
1366           not work or there's kernel crashes after certain hardware
1367           hotplug events) then you might want to enable
1368           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1369           typical corruption patterns.
1370
1371           Leave this to the default value of 64 if you are unsure.
1372
1373 config MATH_EMULATION
1374         bool
1375         prompt "Math emulation" if X86_32
1376         ---help---
1377           Linux can emulate a math coprocessor (used for floating point
1378           operations) if you don't have one. 486DX and Pentium processors have
1379           a math coprocessor built in, 486SX and 386 do not, unless you added
1380           a 487DX or 387, respectively. (The messages during boot time can
1381           give you some hints here ["man dmesg"].) Everyone needs either a
1382           coprocessor or this emulation.
1383
1384           If you don't have a math coprocessor, you need to say Y here; if you
1385           say Y here even though you have a coprocessor, the coprocessor will
1386           be used nevertheless. (This behavior can be changed with the kernel
1387           command line option "no387", which comes handy if your coprocessor
1388           is broken. Try "man bootparam" or see the documentation of your boot
1389           loader (lilo or loadlin) about how to pass options to the kernel at
1390           boot time.) This means that it is a good idea to say Y here if you
1391           intend to use this kernel on different machines.
1392
1393           More information about the internals of the Linux math coprocessor
1394           emulation can be found in <file:arch/x86/math-emu/README>.
1395
1396           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1397           kernel, it won't hurt.
1398
1399 config MTRR
1400         def_bool y
1401         prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1402         ---help---
1403           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1404           the Memory Type Range Registers (MTRRs) may be used to control
1405           processor access to memory ranges. This is most useful if you have
1406           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1407           allows bus write transfers to be combined into a larger transfer
1408           before bursting over the PCI/AGP bus. This can increase performance
1409           of image write operations 2.5 times or more. Saying Y here creates a
1410           /proc/mtrr file which may be used to manipulate your processor's
1411           MTRRs. Typically the X server should use this.
1412
1413           This code has a reasonably generic interface so that similar
1414           control registers on other processors can be easily supported
1415           as well:
1416
1417           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1418           Registers (ARRs) which provide a similar functionality to MTRRs. For
1419           these, the ARRs are used to emulate the MTRRs.
1420           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1421           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1422           write-combining. All of these processors are supported by this code
1423           and it makes sense to say Y here if you have one of them.
1424
1425           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1426           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1427           can lead to all sorts of problems, so it's good to say Y here.
1428
1429           You can safely say Y even if your machine doesn't have MTRRs, you'll
1430           just add about 9 KB to your kernel.
1431
1432           See <file:Documentation/x86/mtrr.txt> for more information.
1433
1434 config MTRR_SANITIZER
1435         def_bool y
1436         prompt "MTRR cleanup support"
1437         depends on MTRR
1438         ---help---
1439           Convert MTRR layout from continuous to discrete, so X drivers can
1440           add writeback entries.
1441
1442           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1443           The largest mtrr entry size for a continuous block can be set with
1444           mtrr_chunk_size.
1445
1446           If unsure, say Y.
1447
1448 config MTRR_SANITIZER_ENABLE_DEFAULT
1449         int "MTRR cleanup enable value (0-1)"
1450         range 0 1
1451         default "0"
1452         depends on MTRR_SANITIZER
1453         ---help---
1454           Enable mtrr cleanup default value
1455
1456 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1457         int "MTRR cleanup spare reg num (0-7)"
1458         range 0 7
1459         default "1"
1460         depends on MTRR_SANITIZER
1461         ---help---
1462           mtrr cleanup spare entries default, it can be changed via
1463           mtrr_spare_reg_nr=N on the kernel command line.
1464
1465 config X86_PAT
1466         def_bool y
1467         prompt "x86 PAT support" if EMBEDDED
1468         depends on MTRR
1469         ---help---
1470           Use PAT attributes to setup page level cache control.
1471
1472           PATs are the modern equivalents of MTRRs and are much more
1473           flexible than MTRRs.
1474
1475           Say N here if you see bootup problems (boot crash, boot hang,
1476           spontaneous reboots) or a non-working video driver.
1477
1478           If unsure, say Y.
1479
1480 config ARCH_USES_PG_UNCACHED
1481         def_bool y
1482         depends on X86_PAT
1483
1484 config EFI
1485         bool "EFI runtime service support"
1486         depends on ACPI
1487         ---help---
1488           This enables the kernel to use EFI runtime services that are
1489           available (such as the EFI variable services).
1490
1491           This option is only useful on systems that have EFI firmware.
1492           In addition, you should use the latest ELILO loader available
1493           at <http://elilo.sourceforge.net> in order to take advantage
1494           of EFI runtime services. However, even with this option, the
1495           resultant kernel should continue to boot on existing non-EFI
1496           platforms.
1497
1498 config SECCOMP
1499         def_bool y
1500         prompt "Enable seccomp to safely compute untrusted bytecode"
1501         ---help---
1502           This kernel feature is useful for number crunching applications
1503           that may need to compute untrusted bytecode during their
1504           execution. By using pipes or other transports made available to
1505           the process as file descriptors supporting the read/write
1506           syscalls, it's possible to isolate those applications in
1507           their own address space using seccomp. Once seccomp is
1508           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1509           and the task is only allowed to execute a few safe syscalls
1510           defined by each seccomp mode.
1511
1512           If unsure, say Y. Only embedded should say N here.
1513
1514 config CC_STACKPROTECTOR
1515         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1516         ---help---
1517           This option turns on the -fstack-protector GCC feature. This
1518           feature puts, at the beginning of functions, a canary value on
1519           the stack just before the return address, and validates
1520           the value just before actually returning.  Stack based buffer
1521           overflows (that need to overwrite this return address) now also
1522           overwrite the canary, which gets detected and the attack is then
1523           neutralized via a kernel panic.
1524
1525           This feature requires gcc version 4.2 or above, or a distribution
1526           gcc with the feature backported. Older versions are automatically
1527           detected and for those versions, this configuration option is
1528           ignored. (and a warning is printed during bootup)
1529
1530 source kernel/Kconfig.hz
1531
1532 config KEXEC
1533         bool "kexec system call"
1534         ---help---
1535           kexec is a system call that implements the ability to shutdown your
1536           current kernel, and to start another kernel.  It is like a reboot
1537           but it is independent of the system firmware.   And like a reboot
1538           you can start any kernel with it, not just Linux.
1539
1540           The name comes from the similarity to the exec system call.
1541
1542           It is an ongoing process to be certain the hardware in a machine
1543           is properly shutdown, so do not be surprised if this code does not
1544           initially work for you.  It may help to enable device hotplugging
1545           support.  As of this writing the exact hardware interface is
1546           strongly in flux, so no good recommendation can be made.
1547
1548 config CRASH_DUMP
1549         bool "kernel crash dumps"
1550         depends on X86_64 || (X86_32 && HIGHMEM)
1551         ---help---
1552           Generate crash dump after being started by kexec.
1553           This should be normally only set in special crash dump kernels
1554           which are loaded in the main kernel with kexec-tools into
1555           a specially reserved region and then later executed after
1556           a crash by kdump/kexec. The crash dump kernel must be compiled
1557           to a memory address not used by the main kernel or BIOS using
1558           PHYSICAL_START, or it must be built as a relocatable image
1559           (CONFIG_RELOCATABLE=y).
1560           For more details see Documentation/kdump/kdump.txt
1561
1562 config KEXEC_JUMP
1563         bool "kexec jump (EXPERIMENTAL)"
1564         depends on EXPERIMENTAL
1565         depends on KEXEC && HIBERNATION
1566         ---help---
1567           Jump between original kernel and kexeced kernel and invoke
1568           code in physical address mode via KEXEC
1569
1570 config PHYSICAL_START
1571         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1572         default "0x1000000"
1573         ---help---
1574           This gives the physical address where the kernel is loaded.
1575
1576           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1577           bzImage will decompress itself to above physical address and
1578           run from there. Otherwise, bzImage will run from the address where
1579           it has been loaded by the boot loader and will ignore above physical
1580           address.
1581
1582           In normal kdump cases one does not have to set/change this option
1583           as now bzImage can be compiled as a completely relocatable image
1584           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1585           address. This option is mainly useful for the folks who don't want
1586           to use a bzImage for capturing the crash dump and want to use a
1587           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1588           to be specifically compiled to run from a specific memory area
1589           (normally a reserved region) and this option comes handy.
1590
1591           So if you are using bzImage for capturing the crash dump,
1592           leave the value here unchanged to 0x1000000 and set
1593           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1594           for capturing the crash dump change this value to start of
1595           the reserved region.  In other words, it can be set based on
1596           the "X" value as specified in the "crashkernel=YM@XM"
1597           command line boot parameter passed to the panic-ed
1598           kernel. Please take a look at Documentation/kdump/kdump.txt
1599           for more details about crash dumps.
1600
1601           Usage of bzImage for capturing the crash dump is recommended as
1602           one does not have to build two kernels. Same kernel can be used
1603           as production kernel and capture kernel. Above option should have
1604           gone away after relocatable bzImage support is introduced. But it
1605           is present because there are users out there who continue to use
1606           vmlinux for dump capture. This option should go away down the
1607           line.
1608
1609           Don't change this unless you know what you are doing.
1610
1611 config RELOCATABLE
1612         bool "Build a relocatable kernel"
1613         default y
1614         ---help---
1615           This builds a kernel image that retains relocation information
1616           so it can be loaded someplace besides the default 1MB.
1617           The relocations tend to make the kernel binary about 10% larger,
1618           but are discarded at runtime.
1619
1620           One use is for the kexec on panic case where the recovery kernel
1621           must live at a different physical address than the primary
1622           kernel.
1623
1624           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1625           it has been loaded at and the compile time physical address
1626           (CONFIG_PHYSICAL_START) is ignored.
1627
1628 # Relocation on x86-32 needs some additional build support
1629 config X86_NEED_RELOCS
1630         def_bool y
1631         depends on X86_32 && RELOCATABLE
1632
1633 config PHYSICAL_ALIGN
1634         hex "Alignment value to which kernel should be aligned" if X86_32
1635         default "0x1000000"
1636         range 0x2000 0x1000000
1637         ---help---
1638           This value puts the alignment restrictions on physical address
1639           where kernel is loaded and run from. Kernel is compiled for an
1640           address which meets above alignment restriction.
1641
1642           If bootloader loads the kernel at a non-aligned address and
1643           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1644           address aligned to above value and run from there.
1645
1646           If bootloader loads the kernel at a non-aligned address and
1647           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1648           load address and decompress itself to the address it has been
1649           compiled for and run from there. The address for which kernel is
1650           compiled already meets above alignment restrictions. Hence the
1651           end result is that kernel runs from a physical address meeting
1652           above alignment restrictions.
1653
1654           Don't change this unless you know what you are doing.
1655
1656 config HOTPLUG_CPU
1657         bool "Support for hot-pluggable CPUs"
1658         depends on SMP && HOTPLUG
1659         ---help---
1660           Say Y here to allow turning CPUs off and on. CPUs can be
1661           controlled through /sys/devices/system/cpu.
1662           ( Note: power management support will enable this option
1663             automatically on SMP systems. )
1664           Say N if you want to disable CPU hotplug.
1665
1666 config COMPAT_VDSO
1667         def_bool y
1668         prompt "Compat VDSO support"
1669         depends on X86_32 || IA32_EMULATION
1670         ---help---
1671           Map the 32-bit VDSO to the predictable old-style address too.
1672
1673           Say N here if you are running a sufficiently recent glibc
1674           version (2.3.3 or later), to remove the high-mapped
1675           VDSO mapping and to exclusively use the randomized VDSO.
1676
1677           If unsure, say Y.
1678
1679 config CMDLINE_BOOL
1680         bool "Built-in kernel command line"
1681         ---help---
1682           Allow for specifying boot arguments to the kernel at
1683           build time.  On some systems (e.g. embedded ones), it is
1684           necessary or convenient to provide some or all of the
1685           kernel boot arguments with the kernel itself (that is,
1686           to not rely on the boot loader to provide them.)
1687
1688           To compile command line arguments into the kernel,
1689           set this option to 'Y', then fill in the
1690           the boot arguments in CONFIG_CMDLINE.
1691
1692           Systems with fully functional boot loaders (i.e. non-embedded)
1693           should leave this option set to 'N'.
1694
1695 config CMDLINE
1696         string "Built-in kernel command string"
1697         depends on CMDLINE_BOOL
1698         default ""
1699         ---help---
1700           Enter arguments here that should be compiled into the kernel
1701           image and used at boot time.  If the boot loader provides a
1702           command line at boot time, it is appended to this string to
1703           form the full kernel command line, when the system boots.
1704
1705           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1706           change this behavior.
1707
1708           In most cases, the command line (whether built-in or provided
1709           by the boot loader) should specify the device for the root
1710           file system.
1711
1712 config CMDLINE_OVERRIDE
1713         bool "Built-in command line overrides boot loader arguments"
1714         depends on CMDLINE_BOOL
1715         ---help---
1716           Set this option to 'Y' to have the kernel ignore the boot loader
1717           command line, and use ONLY the built-in command line.
1718
1719           This is used to work around broken boot loaders.  This should
1720           be set to 'N' under normal conditions.
1721
1722 endmenu
1723
1724 config ARCH_ENABLE_MEMORY_HOTPLUG
1725         def_bool y
1726         depends on X86_64 || (X86_32 && HIGHMEM)
1727
1728 config ARCH_ENABLE_MEMORY_HOTREMOVE
1729         def_bool y
1730         depends on MEMORY_HOTPLUG
1731
1732 config HAVE_ARCH_EARLY_PFN_TO_NID
1733         def_bool X86_64
1734         depends on NUMA
1735
1736 config USE_PERCPU_NUMA_NODE_ID
1737         def_bool X86_64
1738         depends on NUMA
1739
1740 menu "Power management and ACPI options"
1741
1742 config ARCH_HIBERNATION_HEADER
1743         def_bool y
1744         depends on X86_64 && HIBERNATION
1745
1746 source "kernel/power/Kconfig"
1747
1748 source "drivers/acpi/Kconfig"
1749
1750 source "drivers/sfi/Kconfig"
1751
1752 config X86_APM_BOOT
1753         def_bool y
1754         depends on APM || APM_MODULE
1755
1756 menuconfig APM
1757         tristate "APM (Advanced Power Management) BIOS support"
1758         depends on X86_32 && PM_SLEEP
1759         ---help---
1760           APM is a BIOS specification for saving power using several different
1761           techniques. This is mostly useful for battery powered laptops with
1762           APM compliant BIOSes. If you say Y here, the system time will be
1763           reset after a RESUME operation, the /proc/apm device will provide
1764           battery status information, and user-space programs will receive
1765           notification of APM "events" (e.g. battery status change).
1766
1767           If you select "Y" here, you can disable actual use of the APM
1768           BIOS by passing the "apm=off" option to the kernel at boot time.
1769
1770           Note that the APM support is almost completely disabled for
1771           machines with more than one CPU.
1772
1773           In order to use APM, you will need supporting software. For location
1774           and more information, read <file:Documentation/power/pm.txt> and the
1775           Battery Powered Linux mini-HOWTO, available from
1776           <http://www.tldp.org/docs.html#howto>.
1777
1778           This driver does not spin down disk drives (see the hdparm(8)
1779           manpage ("man 8 hdparm") for that), and it doesn't turn off
1780           VESA-compliant "green" monitors.
1781
1782           This driver does not support the TI 4000M TravelMate and the ACER
1783           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1784           desktop machines also don't have compliant BIOSes, and this driver
1785           may cause those machines to panic during the boot phase.
1786
1787           Generally, if you don't have a battery in your machine, there isn't
1788           much point in using this driver and you should say N. If you get
1789           random kernel OOPSes or reboots that don't seem to be related to
1790           anything, try disabling/enabling this option (or disabling/enabling
1791           APM in your BIOS).
1792
1793           Some other things you should try when experiencing seemingly random,
1794           "weird" problems:
1795
1796           1) make sure that you have enough swap space and that it is
1797           enabled.
1798           2) pass the "no-hlt" option to the kernel
1799           3) switch on floating point emulation in the kernel and pass
1800           the "no387" option to the kernel
1801           4) pass the "floppy=nodma" option to the kernel
1802           5) pass the "mem=4M" option to the kernel (thereby disabling
1803           all but the first 4 MB of RAM)
1804           6) make sure that the CPU is not over clocked.
1805           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1806           8) disable the cache from your BIOS settings
1807           9) install a fan for the video card or exchange video RAM
1808           10) install a better fan for the CPU
1809           11) exchange RAM chips
1810           12) exchange the motherboard.
1811
1812           To compile this driver as a module, choose M here: the
1813           module will be called apm.
1814
1815 if APM
1816
1817 config APM_IGNORE_USER_SUSPEND
1818         bool "Ignore USER SUSPEND"
1819         ---help---
1820           This option will ignore USER SUSPEND requests. On machines with a
1821           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1822           series notebooks, it is necessary to say Y because of a BIOS bug.
1823
1824 config APM_DO_ENABLE
1825         bool "Enable PM at boot time"
1826         ---help---
1827           Enable APM features at boot time. From page 36 of the APM BIOS
1828           specification: "When disabled, the APM BIOS does not automatically
1829           power manage devices, enter the Standby State, enter the Suspend
1830           State, or take power saving steps in response to CPU Idle calls."
1831           This driver will make CPU Idle calls when Linux is idle (unless this
1832           feature is turned off -- see "Do CPU IDLE calls", below). This
1833           should always save battery power, but more complicated APM features
1834           will be dependent on your BIOS implementation. You may need to turn
1835           this option off if your computer hangs at boot time when using APM
1836           support, or if it beeps continuously instead of suspending. Turn
1837           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1838           T400CDT. This is off by default since most machines do fine without
1839           this feature.
1840
1841 config APM_CPU_IDLE
1842         bool "Make CPU Idle calls when idle"
1843         ---help---
1844           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1845           On some machines, this can activate improved power savings, such as
1846           a slowed CPU clock rate, when the machine is idle. These idle calls
1847           are made after the idle loop has run for some length of time (e.g.,
1848           333 mS). On some machines, this will cause a hang at boot time or
1849           whenever the CPU becomes idle. (On machines with more than one CPU,
1850           this option does nothing.)
1851
1852 config APM_DISPLAY_BLANK
1853         bool "Enable console blanking using APM"
1854         ---help---
1855           Enable console blanking using the APM. Some laptops can use this to
1856           turn off the LCD backlight when the screen blanker of the Linux
1857           virtual console blanks the screen. Note that this is only used by
1858           the virtual console screen blanker, and won't turn off the backlight
1859           when using the X Window system. This also doesn't have anything to
1860           do with your VESA-compliant power-saving monitor. Further, this
1861           option doesn't work for all laptops -- it might not turn off your
1862           backlight at all, or it might print a lot of errors to the console,
1863           especially if you are using gpm.
1864
1865 config APM_ALLOW_INTS
1866         bool "Allow interrupts during APM BIOS calls"
1867         ---help---
1868           Normally we disable external interrupts while we are making calls to
1869           the APM BIOS as a measure to lessen the effects of a badly behaving
1870           BIOS implementation.  The BIOS should reenable interrupts if it
1871           needs to.  Unfortunately, some BIOSes do not -- especially those in
1872           many of the newer IBM Thinkpads.  If you experience hangs when you
1873           suspend, try setting this to Y.  Otherwise, say N.
1874
1875 endif # APM
1876
1877 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1878
1879 source "drivers/cpuidle/Kconfig"
1880
1881 source "drivers/idle/Kconfig"
1882
1883 endmenu
1884
1885
1886 menu "Bus options (PCI etc.)"
1887
1888 config PCI
1889         bool "PCI support"
1890         default y
1891         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1892         ---help---
1893           Find out whether you have a PCI motherboard. PCI is the name of a
1894           bus system, i.e. the way the CPU talks to the other stuff inside
1895           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1896           VESA. If you have PCI, say Y, otherwise N.
1897
1898 choice
1899         prompt "PCI access mode"
1900         depends on X86_32 && PCI
1901         default PCI_GOANY
1902         ---help---
1903           On PCI systems, the BIOS can be used to detect the PCI devices and
1904           determine their configuration. However, some old PCI motherboards
1905           have BIOS bugs and may crash if this is done. Also, some embedded
1906           PCI-based systems don't have any BIOS at all. Linux can also try to
1907           detect the PCI hardware directly without using the BIOS.
1908
1909           With this option, you can specify how Linux should detect the
1910           PCI devices. If you choose "BIOS", the BIOS will be used,
1911           if you choose "Direct", the BIOS won't be used, and if you
1912           choose "MMConfig", then PCI Express MMCONFIG will be used.
1913           If you choose "Any", the kernel will try MMCONFIG, then the
1914           direct access method and falls back to the BIOS if that doesn't
1915           work. If unsure, go with the default, which is "Any".
1916
1917 config PCI_GOBIOS
1918         bool "BIOS"
1919
1920 config PCI_GOMMCONFIG
1921         bool "MMConfig"
1922
1923 config PCI_GODIRECT
1924         bool "Direct"
1925
1926 config PCI_GOOLPC
1927         bool "OLPC"
1928         depends on OLPC
1929
1930 config PCI_GOANY
1931         bool "Any"
1932
1933 endchoice
1934
1935 config PCI_BIOS
1936         def_bool y
1937         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1938
1939 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1940 config PCI_DIRECT
1941         def_bool y
1942         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1943
1944 config PCI_MMCONFIG
1945         def_bool y
1946         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1947
1948 config PCI_OLPC
1949         def_bool y
1950         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1951
1952 config PCI_DOMAINS
1953         def_bool y
1954         depends on PCI
1955
1956 config PCI_MMCONFIG
1957         bool "Support mmconfig PCI config space access"
1958         depends on X86_64 && PCI && ACPI
1959
1960 config PCI_CNB20LE_QUIRK
1961         bool "Read CNB20LE Host Bridge Windows"
1962         depends on PCI
1963         help
1964           Read the PCI windows out of the CNB20LE host bridge. This allows
1965           PCI hotplug to work on systems with the CNB20LE chipset which do
1966           not have ACPI.
1967
1968 config DMAR
1969         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1970         depends on PCI_MSI && ACPI && EXPERIMENTAL
1971         help
1972           DMA remapping (DMAR) devices support enables independent address
1973           translations for Direct Memory Access (DMA) from devices.
1974           These DMA remapping devices are reported via ACPI tables
1975           and include PCI device scope covered by these DMA
1976           remapping devices.
1977
1978 config DMAR_DEFAULT_ON
1979         def_bool y
1980         prompt "Enable DMA Remapping Devices by default"
1981         depends on DMAR
1982         help
1983           Selecting this option will enable a DMAR device at boot time if
1984           one is found. If this option is not selected, DMAR support can
1985           be enabled by passing intel_iommu=on to the kernel. It is
1986           recommended you say N here while the DMAR code remains
1987           experimental.
1988
1989 config DMAR_BROKEN_GFX_WA
1990         bool "Workaround broken graphics drivers (going away soon)"
1991         depends on DMAR && BROKEN
1992         ---help---
1993           Current Graphics drivers tend to use physical address
1994           for DMA and avoid using DMA APIs. Setting this config
1995           option permits the IOMMU driver to set a unity map for
1996           all the OS-visible memory. Hence the driver can continue
1997           to use physical addresses for DMA, at least until this
1998           option is removed in the 2.6.32 kernel.
1999
2000 config DMAR_FLOPPY_WA
2001         def_bool y
2002         depends on DMAR
2003         ---help---
2004           Floppy disk drivers are known to bypass DMA API calls
2005           thereby failing to work when IOMMU is enabled. This
2006           workaround will setup a 1:1 mapping for the first
2007           16MiB to make floppy (an ISA device) work.
2008
2009 config INTR_REMAP
2010         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
2011         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
2012         ---help---
2013           Supports Interrupt remapping for IO-APIC and MSI devices.
2014           To use x2apic mode in the CPU's which support x2APIC enhancements or
2015           to support platforms with CPU's having > 8 bit APIC ID, say Y.
2016
2017 source "drivers/pci/pcie/Kconfig"
2018
2019 source "drivers/pci/Kconfig"
2020
2021 # x86_64 have no ISA slots, but do have ISA-style DMA.
2022 config ISA_DMA_API
2023         def_bool y
2024
2025 if X86_32
2026
2027 config ISA
2028         bool "ISA support"
2029         ---help---
2030           Find out whether you have ISA slots on your motherboard.  ISA is the
2031           name of a bus system, i.e. the way the CPU talks to the other stuff
2032           inside your box.  Other bus systems are PCI, EISA, MicroChannel
2033           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
2034           newer boards don't support it.  If you have ISA, say Y, otherwise N.
2035
2036 config EISA
2037         bool "EISA support"
2038         depends on ISA
2039         ---help---
2040           The Extended Industry Standard Architecture (EISA) bus was
2041           developed as an open alternative to the IBM MicroChannel bus.
2042
2043           The EISA bus provided some of the features of the IBM MicroChannel
2044           bus while maintaining backward compatibility with cards made for
2045           the older ISA bus.  The EISA bus saw limited use between 1988 and
2046           1995 when it was made obsolete by the PCI bus.
2047
2048           Say Y here if you are building a kernel for an EISA-based machine.
2049
2050           Otherwise, say N.
2051
2052 source "drivers/eisa/Kconfig"
2053
2054 config MCA
2055         bool "MCA support"
2056         ---help---
2057           MicroChannel Architecture is found in some IBM PS/2 machines and
2058           laptops.  It is a bus system similar to PCI or ISA. See
2059           <file:Documentation/mca.txt> (and especially the web page given
2060           there) before attempting to build an MCA bus kernel.
2061
2062 source "drivers/mca/Kconfig"
2063
2064 config SCx200
2065         tristate "NatSemi SCx200 support"
2066         ---help---
2067           This provides basic support for National Semiconductor's
2068           (now AMD's) Geode processors.  The driver probes for the
2069           PCI-IDs of several on-chip devices, so its a good dependency
2070           for other scx200_* drivers.
2071
2072           If compiled as a module, the driver is named scx200.
2073
2074 config SCx200HR_TIMER
2075         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2076         depends on SCx200
2077         default y
2078         ---help---
2079           This driver provides a clocksource built upon the on-chip
2080           27MHz high-resolution timer.  Its also a workaround for
2081           NSC Geode SC-1100's buggy TSC, which loses time when the
2082           processor goes idle (as is done by the scheduler).  The
2083           other workaround is idle=poll boot option.
2084
2085 config OLPC
2086         bool "One Laptop Per Child support"
2087         select GPIOLIB
2088         ---help---
2089           Add support for detecting the unique features of the OLPC
2090           XO hardware.
2091
2092 config OLPC_OPENFIRMWARE
2093         bool "Support for OLPC's Open Firmware"
2094         depends on !X86_64 && !X86_PAE
2095         default y if OLPC
2096         help
2097           This option adds support for the implementation of Open Firmware
2098           that is used on the OLPC XO-1 Children's Machine.
2099           If unsure, say N here.
2100
2101 endif # X86_32
2102
2103 config AMD_NB
2104         def_bool y
2105         depends on CPU_SUP_AMD && PCI
2106
2107 source "drivers/pcmcia/Kconfig"
2108
2109 source "drivers/pci/hotplug/Kconfig"
2110
2111 endmenu
2112
2113
2114 menu "Executable file formats / Emulations"
2115
2116 source "fs/Kconfig.binfmt"
2117
2118 config IA32_EMULATION
2119         bool "IA32 Emulation"
2120         depends on X86_64
2121         select COMPAT_BINFMT_ELF
2122         ---help---
2123           Include code to run 32-bit programs under a 64-bit kernel. You should
2124           likely turn this on, unless you're 100% sure that you don't have any
2125           32-bit programs left.
2126
2127 config IA32_AOUT
2128         tristate "IA32 a.out support"
2129         depends on IA32_EMULATION
2130         ---help---
2131           Support old a.out binaries in the 32bit emulation.
2132
2133 config COMPAT
2134         def_bool y
2135         depends on IA32_EMULATION
2136
2137 config COMPAT_FOR_U64_ALIGNMENT
2138         def_bool COMPAT
2139         depends on X86_64
2140
2141 config SYSVIPC_COMPAT
2142         def_bool y
2143         depends on COMPAT && SYSVIPC
2144
2145 endmenu
2146
2147
2148 config HAVE_ATOMIC_IOMAP
2149         def_bool y
2150         depends on X86_32
2151
2152 config HAVE_TEXT_POKE_SMP
2153         bool
2154         select STOP_MACHINE if SMP
2155
2156 source "net/Kconfig"
2157
2158 source "drivers/Kconfig"
2159
2160 source "drivers/firmware/Kconfig"
2161
2162 source "fs/Kconfig"
2163
2164 source "arch/x86/Kconfig.debug"
2165
2166 source "security/Kconfig"
2167
2168 source "crypto/Kconfig"
2169
2170 source "arch/x86/kvm/Kconfig"
2171
2172 source "lib/Kconfig"