arch/x86/Kconfig

   1 # Select 32 or 64 bit
   2 config 64BIT
   3         bool "64-bit kernel" if ARCH = "x86"
   4         default ARCH = "x86_64"
   5         ---help---
   6           Say yes to build a 64-bit kernel - formerly known as x86_64
   7           Say no to build a 32-bit kernel - formerly known as i386
   8
   9 config X86_32
  10         def_bool !64BIT
  11         select CLKSRC_I8253
  12
  13 config X86_64
  14         def_bool 64BIT
  15
  16 ### Arch settings
  17 config X86
  18         def_bool y
  19         select HAVE_AOUT if X86_32
  20         select HAVE_UNSTABLE_SCHED_CLOCK
  21         select HAVE_IDE
  22         select HAVE_OPROFILE
  23         select HAVE_PCSPKR_PLATFORM
  24         select HAVE_PERF_EVENTS
  25         select HAVE_IRQ_WORK
  26         select HAVE_IOREMAP_PROT
  27         select HAVE_KPROBES
  28         select HAVE_MEMBLOCK
  29         select HAVE_MEMBLOCK_NODE_MAP
  30         select ARCH_DISCARD_MEMBLOCK
  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_XZ
  57         select HAVE_KERNEL_LZO
  58         select HAVE_HW_BREAKPOINT
  59         select HAVE_MIXED_BREAKPOINTS_REGS
  60         select PERF_EVENTS
  61         select HAVE_PERF_EVENTS_NMI
  62         select ANON_INODES
  63         select HAVE_ARCH_KMEMCHECK
  64         select HAVE_USER_RETURN_NOTIFIER
  65         select HAVE_ARCH_JUMP_LABEL
  66         select HAVE_TEXT_POKE_SMP
  67         select HAVE_GENERIC_HARDIRQS
  68         select HAVE_SPARSE_IRQ
  69         select SPARSE_IRQ
  70         select GENERIC_FIND_FIRST_BIT
  71         select GENERIC_IRQ_PROBE
  72         select GENERIC_PENDING_IRQ if SMP
  73         select GENERIC_IRQ_SHOW
  74         select GENERIC_CLOCKEVENTS_MIN_ADJUST
  75         select IRQ_FORCED_THREADING
  76         select USE_GENERIC_SMP_HELPERS if SMP
  77         select HAVE_BPF_JIT if (X86_64 && NET)
  78         select CLKEVT_I8253
  79         select ARCH_HAVE_NMI_SAFE_CMPXCHG
  80
  81 config INSTRUCTION_DECODER
  82         def_bool (KPROBES || PERF_EVENTS)
  83
  84 config OUTPUT_FORMAT
  85         string
  86         default "elf32-i386" if X86_32
  87         default "elf64-x86-64" if X86_64
  88
  89 config ARCH_DEFCONFIG
  90         string
  91         default "arch/x86/configs/i386_defconfig" if X86_32
  92         default "arch/x86/configs/x86_64_defconfig" if X86_64
  93
  94 config GENERIC_CMOS_UPDATE
  95         def_bool y
  96
  97 config CLOCKSOURCE_WATCHDOG
  98         def_bool y
  99
 100 config GENERIC_CLOCKEVENTS
 101         def_bool y
 102
 103 config ARCH_CLOCKSOURCE_DATA
 104         def_bool y
 105         depends on X86_64
 106
 107 config GENERIC_CLOCKEVENTS_BROADCAST
 108         def_bool y
 109         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
 110
 111 config LOCKDEP_SUPPORT
 112         def_bool y
 113
 114 config STACKTRACE_SUPPORT
 115         def_bool y
 116
 117 config HAVE_LATENCYTOP_SUPPORT
 118         def_bool y
 119
 120 config MMU
 121         def_bool y
 122
 123 config ZONE_DMA
 124         bool "DMA memory allocation support" if EXPERT
 125         default y
 126         help
 127           DMA memory allocation support allows devices with less than 32-bit
 128           addressing to allocate within the first 16MB of address space.
 129           Disable if no such devices will be used.
 130
 131           If unsure, say Y.
 132
 133 config SBUS
 134         bool
 135
 136 config NEED_DMA_MAP_STATE
 137        def_bool (X86_64 || INTEL_IOMMU || DMA_API_DEBUG)
 138
 139 config NEED_SG_DMA_LENGTH
 140         def_bool y
 141
 142 config GENERIC_ISA_DMA
 143         def_bool ISA_DMA_API
 144
 145 config GENERIC_IOMAP
 146         def_bool y
 147
 148 config GENERIC_BUG
 149         def_bool y
 150         depends on BUG
 151         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 152
 153 config GENERIC_BUG_RELATIVE_POINTERS
 154         bool
 155
 156 config GENERIC_HWEIGHT
 157         def_bool y
 158
 159 config GENERIC_GPIO
 160         bool
 161
 162 config ARCH_MAY_HAVE_PC_FDC
 163         def_bool ISA_DMA_API
 164
 165 config RWSEM_GENERIC_SPINLOCK
 166         def_bool !X86_XADD
 167
 168 config RWSEM_XCHGADD_ALGORITHM
 169         def_bool X86_XADD
 170
 171 config ARCH_HAS_CPU_IDLE_WAIT
 172         def_bool y
 173
 174 config GENERIC_CALIBRATE_DELAY
 175         def_bool y
 176
 177 config GENERIC_TIME_VSYSCALL
 178         bool
 179         default X86_64
 180
 181 config ARCH_HAS_CPU_RELAX
 182         def_bool y
 183
 184 config ARCH_HAS_DEFAULT_IDLE
 185         def_bool y
 186
 187 config ARCH_HAS_CACHE_LINE_SIZE
 188         def_bool y
 189
 190 config HAVE_SETUP_PER_CPU_AREA
 191         def_bool y
 192
 193 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 194         def_bool y
 195
 196 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 197         def_bool y
 198
 199 config ARCH_HIBERNATION_POSSIBLE
 200         def_bool y
 201
 202 config ARCH_SUSPEND_POSSIBLE
 203         def_bool y
 204
 205 config ZONE_DMA32
 206         bool
 207         default X86_64
 208
 209 config AUDIT_ARCH
 210         bool
 211         default X86_64
 212
 213 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 214         def_bool y
 215
 216 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 217         def_bool y
 218
 219 config HAVE_INTEL_TXT
 220         def_bool y
 221         depends on EXPERIMENTAL && INTEL_IOMMU && ACPI
 222
 223 config X86_32_SMP
 224         def_bool y
 225         depends on X86_32 && SMP
 226
 227 config X86_64_SMP
 228         def_bool y
 229         depends on X86_64 && SMP
 230
 231 config X86_HT
 232         def_bool y
 233         depends on SMP
 234
 235 config X86_32_LAZY_GS
 236         def_bool y
 237         depends on X86_32 && !CC_STACKPROTECTOR
 238
 239 config ARCH_HWEIGHT_CFLAGS
 240         string
 241         default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
 242         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
 243
 244 config KTIME_SCALAR
 245         def_bool X86_32
 246
 247 config ARCH_CPU_PROBE_RELEASE
 248         def_bool y
 249         depends on HOTPLUG_CPU
 250
 251 source "init/Kconfig"
 252 source "kernel/Kconfig.freezer"
 253
 254 menu "Processor type and features"
 255
 256 source "kernel/time/Kconfig"
 257
 258 config SMP
 259         bool "Symmetric multi-processing support"
 260         ---help---
 261           This enables support for systems with more than one CPU. If you have
 262           a system with only one CPU, like most personal computers, say N. If
 263           you have a system with more than one CPU, say Y.
 264
 265           If you say N here, the kernel will run on single and multiprocessor
 266           machines, but will use only one CPU of a multiprocessor machine. If
 267           you say Y here, the kernel will run on many, but not all,
 268           singleprocessor machines. On a singleprocessor machine, the kernel
 269           will run faster if you say N here.
 270
 271           Note that if you say Y here and choose architecture "586" or
 272           "Pentium" under "Processor family", the kernel will not work on 486
 273           architectures. Similarly, multiprocessor kernels for the "PPro"
 274           architecture may not work on all Pentium based boards.
 275
 276           People using multiprocessor machines who say Y here should also say
 277           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 278           Management" code will be disabled if you say Y here.
 279
 280           See also <file:Documentation/x86/i386/IO-APIC.txt>,
 281           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 282           <http://www.tldp.org/docs.html#howto>.
 283
 284           If you don't know what to do here, say N.
 285
 286 config X86_X2APIC
 287         bool "Support x2apic"
 288         depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP
 289         ---help---
 290           This enables x2apic support on CPUs that have this feature.
 291
 292           This allows 32-bit apic IDs (so it can support very large systems),
 293           and accesses the local apic via MSRs not via mmio.
 294
 295           If you don't know what to do here, say N.
 296
 297 config X86_MPPARSE
 298         bool "Enable MPS table" if ACPI
 299         default y
 300         depends on X86_LOCAL_APIC
 301         ---help---
 302           For old smp systems that do not have proper acpi support. Newer systems
 303           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 304
 305 config X86_BIGSMP
 306         bool "Support for big SMP systems with more than 8 CPUs"
 307         depends on X86_32 && SMP
 308         ---help---
 309           This option is needed for the systems that have more than 8 CPUs
 310
 311 if X86_32
 312 config X86_EXTENDED_PLATFORM
 313         bool "Support for extended (non-PC) x86 platforms"
 314         default y
 315         ---help---
 316           If you disable this option then the kernel will only support
 317           standard PC platforms. (which covers the vast majority of
 318           systems out there.)
 319
 320           If you enable this option then you'll be able to select support
 321           for the following (non-PC) 32 bit x86 platforms:
 322                 AMD Elan
 323                 NUMAQ (IBM/Sequent)
 324                 RDC R-321x SoC
 325                 SGI 320/540 (Visual Workstation)
 326                 Summit/EXA (IBM x440)
 327                 Unisys ES7000 IA32 series
 328                 Moorestown MID devices
 329
 330           If you have one of these systems, or if you want to build a
 331           generic distribution kernel, say Y here - otherwise say N.
 332 endif
 333
 334 if X86_64
 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) 64 bit x86 platforms:
 345                 Numascale NumaChip
 346                 ScaleMP vSMP
 347                 SGI Ultraviolet
 348
 349           If you have one of these systems, or if you want to build a
 350           generic distribution kernel, say Y here - otherwise say N.
 351 endif
 352 # This is an alphabetically sorted list of 64 bit extended platforms
 353 # Please maintain the alphabetic order if and when there are additions
 354 config X86_NUMACHIP
 355         bool "Numascale NumaChip"
 356         depends on X86_64
 357         depends on X86_EXTENDED_PLATFORM
 358         depends on NUMA
 359         depends on SMP
 360         depends on X86_X2APIC
 361         depends on !EDAC_AMD64
 362         ---help---
 363           Adds support for Numascale NumaChip large-SMP systems. Needed to
 364           enable more than ~168 cores.
 365           If you don't have one of these, you should say N here.
 366
 367 config X86_VSMP
 368         bool "ScaleMP vSMP"
 369         select PARAVIRT_GUEST
 370         select PARAVIRT
 371         depends on X86_64 && PCI
 372         depends on X86_EXTENDED_PLATFORM
 373         ---help---
 374           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 375           supposed to run on these EM64T-based machines.  Only choose this option
 376           if you have one of these machines.
 377
 378 config X86_UV
 379         bool "SGI Ultraviolet"
 380         depends on X86_64
 381         depends on X86_EXTENDED_PLATFORM
 382         depends on NUMA
 383         depends on X86_X2APIC
 384         ---help---
 385           This option is needed in order to support SGI Ultraviolet systems.
 386           If you don't have one of these, you should say N here.
 387
 388 # Following is an alphabetically sorted list of 32 bit extended platforms
 389 # Please maintain the alphabetic order if and when there are additions
 390
 391 config X86_INTEL_CE
 392         bool "CE4100 TV platform"
 393         depends on PCI
 394         depends on PCI_GODIRECT
 395         depends on X86_32
 396         depends on X86_EXTENDED_PLATFORM
 397         select X86_REBOOTFIXUPS
 398         select OF
 399         select OF_EARLY_FLATTREE
 400         ---help---
 401           Select for the Intel CE media processor (CE4100) SOC.
 402           This option compiles in support for the CE4100 SOC for settop
 403           boxes and media devices.
 404
 405 config X86_WANT_INTEL_MID
 406         bool "Intel MID platform support"
 407         depends on X86_32
 408         depends on X86_EXTENDED_PLATFORM
 409         ---help---
 410           Select to build a kernel capable of supporting Intel MID platform
 411           systems which do not have the PCI legacy interfaces (Moorestown,
 412           Medfield). If you are building for a PC class system say N here.
 413
 414 if X86_WANT_INTEL_MID
 415
 416 config X86_INTEL_MID
 417         bool
 418
 419 config X86_MRST
 420        bool "Moorestown MID platform"
 421         depends on PCI
 422         depends on PCI_GOANY
 423         depends on X86_IO_APIC
 424         select APB_TIMER
 425         select I2C
 426         select SPI
 427         select INTEL_SCU_IPC
 428         select X86_PLATFORM_DEVICES
 429         select X86_INTEL_MID
 430         ---help---
 431           Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 432           Internet Device(MID) platform. Moorestown consists of two chips:
 433           Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
 434           Unlike standard x86 PCs, Moorestown does not have many legacy devices
 435           nor standard legacy replacement devices/features. e.g. Moorestown does
 436           not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
 437
 438 endif
 439
 440 config X86_RDC321X
 441         bool "RDC R-321x SoC"
 442         depends on X86_32
 443         depends on X86_EXTENDED_PLATFORM
 444         select M486
 445         select X86_REBOOTFIXUPS
 446         ---help---
 447           This option is needed for RDC R-321x system-on-chip, also known
 448           as R-8610-(G).
 449           If you don't have one of these chips, you should say N here.
 450
 451 config X86_32_NON_STANDARD
 452         bool "Support non-standard 32-bit SMP architectures"
 453         depends on X86_32 && SMP
 454         depends on X86_EXTENDED_PLATFORM
 455         ---help---
 456           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 457           subarchitectures.  It is intended for a generic binary kernel.
 458           if you select them all, kernel will probe it one by one. and will
 459           fallback to default.
 460
 461 # Alphabetically sorted list of Non standard 32 bit platforms
 462
 463 config X86_NUMAQ
 464         bool "NUMAQ (IBM/Sequent)"
 465         depends on X86_32_NON_STANDARD
 466         depends on PCI
 467         select NUMA
 468         select X86_MPPARSE
 469         ---help---
 470           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 471           NUMA multiquad box. This changes the way that processors are
 472           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 473           of Flat Logical.  You will need a new lynxer.elf file to flash your
 474           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 475
 476 config X86_SUPPORTS_MEMORY_FAILURE
 477         def_bool y
 478         # MCE code calls memory_failure():
 479         depends on X86_MCE
 480         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
 481         depends on !X86_NUMAQ
 482         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
 483         depends on X86_64 || !SPARSEMEM
 484         select ARCH_SUPPORTS_MEMORY_FAILURE
 485
 486 config X86_VISWS
 487         bool "SGI 320/540 (Visual Workstation)"
 488         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 489         depends on X86_32_NON_STANDARD
 490         ---help---
 491           The SGI Visual Workstation series is an IA32-based workstation
 492           based on SGI systems chips with some legacy PC hardware attached.
 493
 494           Say Y here to create a kernel to run on the SGI 320 or 540.
 495
 496           A kernel compiled for the Visual Workstation will run on general
 497           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 498
 499 config X86_SUMMIT
 500         bool "Summit/EXA (IBM x440)"
 501         depends on X86_32_NON_STANDARD
 502         ---help---
 503           This option is needed for IBM systems that use the Summit/EXA chipset.
 504           In particular, it is needed for the x440.
 505
 506 config X86_ES7000
 507         bool "Unisys ES7000 IA32 series"
 508         depends on X86_32_NON_STANDARD && X86_BIGSMP
 509         ---help---
 510           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 511           supposed to run on an IA32-based Unisys ES7000 system.
 512
 513 config X86_32_IRIS
 514         tristate "Eurobraille/Iris poweroff module"
 515         depends on X86_32
 516         ---help---
 517           The Iris machines from EuroBraille do not have APM or ACPI support
 518           to shut themselves down properly.  A special I/O sequence is
 519           needed to do so, which is what this module does at
 520           kernel shutdown.
 521
 522           This is only for Iris machines from EuroBraille.
 523
 524           If unused, say N.
 525
 526 config SCHED_OMIT_FRAME_POINTER
 527         def_bool y
 528         prompt "Single-depth WCHAN output"
 529         depends on X86
 530         ---help---
 531           Calculate simpler /proc/<PID>/wchan values. If this option
 532           is disabled then wchan values will recurse back to the
 533           caller function. This provides more accurate wchan values,
 534           at the expense of slightly more scheduling overhead.
 535
 536           If in doubt, say "Y".
 537
 538 menuconfig PARAVIRT_GUEST
 539         bool "Paravirtualized guest support"
 540         ---help---
 541           Say Y here to get to see options related to running Linux under
 542           various hypervisors.  This option alone does not add any kernel code.
 543
 544           If you say N, all options in this submenu will be skipped and disabled.
 545
 546 if PARAVIRT_GUEST
 547
 548 config PARAVIRT_TIME_ACCOUNTING
 549         bool "Paravirtual steal time accounting"
 550         select PARAVIRT
 551         default n
 552         ---help---
 553           Select this option to enable fine granularity task steal time
 554           accounting. Time spent executing other tasks in parallel with
 555           the current vCPU is discounted from the vCPU power. To account for
 556           that, there can be a small performance impact.
 557
 558           If in doubt, say N here.
 559
 560 source "arch/x86/xen/Kconfig"
 561
 562 config KVM_CLOCK
 563         bool "KVM paravirtualized clock"
 564         select PARAVIRT
 565         select PARAVIRT_CLOCK
 566         ---help---
 567           Turning on this option will allow you to run a paravirtualized clock
 568           when running over the KVM hypervisor. Instead of relying on a PIT
 569           (or probably other) emulation by the underlying device model, the host
 570           provides the guest with timing infrastructure such as time of day, and
 571           system time
 572
 573 config KVM_GUEST
 574         bool "KVM Guest support"
 575         select PARAVIRT
 576         ---help---
 577           This option enables various optimizations for running under the KVM
 578           hypervisor.
 579
 580 source "arch/x86/lguest/Kconfig"
 581
 582 config PARAVIRT
 583         bool "Enable paravirtualization code"
 584         ---help---
 585           This changes the kernel so it can modify itself when it is run
 586           under a hypervisor, potentially improving performance significantly
 587           over full virtualization.  However, when run without a hypervisor
 588           the kernel is theoretically slower and slightly larger.
 589
 590 config PARAVIRT_SPINLOCKS
 591         bool "Paravirtualization layer for spinlocks"
 592         depends on PARAVIRT && SMP && EXPERIMENTAL
 593         ---help---
 594           Paravirtualized spinlocks allow a pvops backend to replace the
 595           spinlock implementation with something virtualization-friendly
 596           (for example, block the virtual CPU rather than spinning).
 597
 598           Unfortunately the downside is an up to 5% performance hit on
 599           native kernels, with various workloads.
 600
 601           If you are unsure how to answer this question, answer N.
 602
 603 config PARAVIRT_CLOCK
 604         bool
 605
 606 endif
 607
 608 config PARAVIRT_DEBUG
 609         bool "paravirt-ops debugging"
 610         depends on PARAVIRT && DEBUG_KERNEL
 611         ---help---
 612           Enable to debug paravirt_ops internals.  Specifically, BUG if
 613           a paravirt_op is missing when it is called.
 614
 615 config NO_BOOTMEM
 616         def_bool y
 617
 618 config MEMTEST
 619         bool "Memtest"
 620         ---help---
 621           This option adds a kernel parameter 'memtest', which allows memtest
 622           to be set.
 623                 memtest=0, mean disabled; -- default
 624                 memtest=1, mean do 1 test pattern;
 625                 ...
 626                 memtest=4, mean do 4 test patterns.
 627           If you are unsure how to answer this question, answer N.
 628
 629 config X86_SUMMIT_NUMA
 630         def_bool y
 631         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 632
 633 config X86_CYCLONE_TIMER
 634         def_bool y
 635         depends on X86_32_NON_STANDARD
 636
 637 source "arch/x86/Kconfig.cpu"
 638
 639 config HPET_TIMER
 640         def_bool X86_64
 641         prompt "HPET Timer Support" if X86_32
 642         ---help---
 643           Use the IA-PC HPET (High Precision Event Timer) to manage
 644           time in preference to the PIT and RTC, if a HPET is
 645           present.
 646           HPET is the next generation timer replacing legacy 8254s.
 647           The HPET provides a stable time base on SMP
 648           systems, unlike the TSC, but it is more expensive to access,
 649           as it is off-chip.  You can find the HPET spec at
 650           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 651
 652           You can safely choose Y here.  However, HPET will only be
 653           activated if the platform and the BIOS support this feature.
 654           Otherwise the 8254 will be used for timing services.
 655
 656           Choose N to continue using the legacy 8254 timer.
 657
 658 config HPET_EMULATE_RTC
 659         def_bool y
 660         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 661
 662 config APB_TIMER
 663        def_bool y if MRST
 664        prompt "Langwell APB Timer Support" if X86_MRST
 665        select DW_APB_TIMER
 666        help
 667          APB timer is the replacement for 8254, HPET on X86 MID platforms.
 668          The APBT provides a stable time base on SMP
 669          systems, unlike the TSC, but it is more expensive to access,
 670          as it is off-chip. APB timers are always running regardless of CPU
 671          C states, they are used as per CPU clockevent device when possible.
 672
 673 # Mark as expert because too many people got it wrong.
 674 # The code disables itself when not needed.
 675 config DMI
 676         default y
 677         bool "Enable DMI scanning" if EXPERT
 678         ---help---
 679           Enabled scanning of DMI to identify machine quirks. Say Y
 680           here unless you have verified that your setup is not
 681           affected by entries in the DMI blacklist. Required by PNP
 682           BIOS code.
 683
 684 config GART_IOMMU
 685         bool "GART IOMMU support" if EXPERT
 686         default y
 687         select SWIOTLB
 688         depends on X86_64 && PCI && AMD_NB
 689         ---help---
 690           Support for full DMA access of devices with 32bit memory access only
 691           on systems with more than 3GB. This is usually needed for USB,
 692           sound, many IDE/SATA chipsets and some other devices.
 693           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 694           based hardware IOMMU and a software bounce buffer based IOMMU used
 695           on Intel systems and as fallback.
 696           The code is only active when needed (enough memory and limited
 697           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 698           too.
 699
 700 config CALGARY_IOMMU
 701         bool "IBM Calgary IOMMU support"
 702         select SWIOTLB
 703         depends on X86_64 && PCI && EXPERIMENTAL
 704         ---help---
 705           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 706           systems. Needed to run systems with more than 3GB of memory
 707           properly with 32-bit PCI devices that do not support DAC
 708           (Double Address Cycle). Calgary also supports bus level
 709           isolation, where all DMAs pass through the IOMMU.  This
 710           prevents them from going anywhere except their intended
 711           destination. This catches hard-to-find kernel bugs and
 712           mis-behaving drivers and devices that do not use the DMA-API
 713           properly to set up their DMA buffers.  The IOMMU can be
 714           turned off at boot time with the iommu=off parameter.
 715           Normally the kernel will make the right choice by itself.
 716           If unsure, say Y.
 717
 718 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 719         def_bool y
 720         prompt "Should Calgary be enabled by default?"
 721         depends on CALGARY_IOMMU
 722         ---help---
 723           Should Calgary be enabled by default? if you choose 'y', Calgary
 724           will be used (if it exists). If you choose 'n', Calgary will not be
 725           used even if it exists. If you choose 'n' and would like to use
 726           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 727           If unsure, say Y.
 728
 729 # need this always selected by IOMMU for the VIA workaround
 730 config SWIOTLB
 731         def_bool y if X86_64
 732         ---help---
 733           Support for software bounce buffers used on x86-64 systems
 734           which don't have a hardware IOMMU (e.g. the current generation
 735           of Intel's x86-64 CPUs). Using this PCI devices which can only
 736           access 32-bits of memory can be used on systems with more than
 737           3 GB of memory. If unsure, say Y.
 738
 739 config IOMMU_HELPER
 740         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 741
 742 config MAXSMP
 743         bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 744         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 745         select CPUMASK_OFFSTACK
 746         ---help---
 747           Enable maximum number of CPUS and NUMA Nodes for this architecture.
 748           If unsure, say N.
 749
 750 config NR_CPUS
 751         int "Maximum number of CPUs" if SMP && !MAXSMP
 752         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 753         range 2 512 if SMP && !MAXSMP
 754         default "1" if !SMP
 755         default "4096" if MAXSMP
 756         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 757         default "8" if SMP
 758         ---help---
 759           This allows you to specify the maximum number of CPUs which this
 760           kernel will support.  The maximum supported value is 512 and the
 761           minimum value which makes sense is 2.
 762
 763           This is purely to save memory - each supported CPU adds
 764           approximately eight kilobytes to the kernel image.
 765
 766 config SCHED_SMT
 767         bool "SMT (Hyperthreading) scheduler support"
 768         depends on X86_HT
 769         ---help---
 770           SMT scheduler support improves the CPU scheduler's decision making
 771           when dealing with Intel Pentium 4 chips with HyperThreading at a
 772           cost of slightly increased overhead in some places. If unsure say
 773           N here.
 774
 775 config SCHED_MC
 776         def_bool y
 777         prompt "Multi-core scheduler support"
 778         depends on X86_HT
 779         ---help---
 780           Multi-core scheduler support improves the CPU scheduler's decision
 781           making when dealing with multi-core CPU chips at a cost of slightly
 782           increased overhead in some places. If unsure say N here.
 783
 784 config IRQ_TIME_ACCOUNTING
 785         bool "Fine granularity task level IRQ time accounting"
 786         default n
 787         ---help---
 788           Select this option to enable fine granularity task irq time
 789           accounting. This is done by reading a timestamp on each
 790           transitions between softirq and hardirq state, so there can be a
 791           small performance impact.
 792
 793           If in doubt, say N here.
 794
 795 source "kernel/Kconfig.preempt"
 796
 797 config X86_UP_APIC
 798         bool "Local APIC support on uniprocessors"
 799         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 800         ---help---
 801           A local APIC (Advanced Programmable Interrupt Controller) is an
 802           integrated interrupt controller in the CPU. If you have a single-CPU
 803           system which has a processor with a local APIC, you can say Y here to
 804           enable and use it. If you say Y here even though your machine doesn't
 805           have a local APIC, then the kernel will still run with no slowdown at
 806           all. The local APIC supports CPU-generated self-interrupts (timer,
 807           performance counters), and the NMI watchdog which detects hard
 808           lockups.
 809
 810 config X86_UP_IOAPIC
 811         bool "IO-APIC support on uniprocessors"
 812         depends on X86_UP_APIC
 813         ---help---
 814           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 815           SMP-capable replacement for PC-style interrupt controllers. Most
 816           SMP systems and many recent uniprocessor systems have one.
 817
 818           If you have a single-CPU system with an IO-APIC, you can say Y here
 819           to use it. If you say Y here even though your machine doesn't have
 820           an IO-APIC, then the kernel will still run with no slowdown at all.
 821
 822 config X86_LOCAL_APIC
 823         def_bool y
 824         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 825
 826 config X86_IO_APIC
 827         def_bool y
 828         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
 829
 830 config X86_VISWS_APIC
 831         def_bool y
 832         depends on X86_32 && X86_VISWS
 833
 834 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 835         bool "Reroute for broken boot IRQs"
 836         depends on X86_IO_APIC
 837         ---help---
 838           This option enables a workaround that fixes a source of
 839           spurious interrupts. This is recommended when threaded
 840           interrupt handling is used on systems where the generation of
 841           superfluous "boot interrupts" cannot be disabled.
 842
 843           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 844           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 845           kernel does during interrupt handling). On chipsets where this
 846           boot IRQ generation cannot be disabled, this workaround keeps
 847           the original IRQ line masked so that only the equivalent "boot
 848           IRQ" is delivered to the CPUs. The workaround also tells the
 849           kernel to set up the IRQ handler on the boot IRQ line. In this
 850           way only one interrupt is delivered to the kernel. Otherwise
 851           the spurious second interrupt may cause the kernel to bring
 852           down (vital) interrupt lines.
 853
 854           Only affects "broken" chipsets. Interrupt sharing may be
 855           increased on these systems.
 856
 857 config X86_MCE
 858         bool "Machine Check / overheating reporting"
 859         ---help---
 860           Machine Check support allows the processor to notify the
 861           kernel if it detects a problem (e.g. overheating, data corruption).
 862           The action the kernel takes depends on the severity of the problem,
 863           ranging from warning messages to halting the machine.
 864
 865 config X86_MCE_INTEL
 866         def_bool y
 867         prompt "Intel MCE features"
 868         depends on X86_MCE && X86_LOCAL_APIC
 869         ---help---
 870            Additional support for intel specific MCE features such as
 871            the thermal monitor.
 872
 873 config X86_MCE_AMD
 874         def_bool y
 875         prompt "AMD MCE features"
 876         depends on X86_MCE && X86_LOCAL_APIC
 877         ---help---
 878            Additional support for AMD specific MCE features such as
 879            the DRAM Error Threshold.
 880
 881 config X86_ANCIENT_MCE
 882         bool "Support for old Pentium 5 / WinChip machine checks"
 883         depends on X86_32 && X86_MCE
 884         ---help---
 885           Include support for machine check handling on old Pentium 5 or WinChip
 886           systems. These typically need to be enabled explicitely on the command
 887           line.
 888
 889 config X86_MCE_THRESHOLD
 890         depends on X86_MCE_AMD || X86_MCE_INTEL
 891         def_bool y
 892
 893 config X86_MCE_INJECT
 894         depends on X86_MCE
 895         tristate "Machine check injector support"
 896         ---help---
 897           Provide support for injecting machine checks for testing purposes.
 898           If you don't know what a machine check is and you don't do kernel
 899           QA it is safe to say n.
 900
 901 config X86_THERMAL_VECTOR
 902         def_bool y
 903         depends on X86_MCE_INTEL
 904
 905 config VM86
 906         bool "Enable VM86 support" if EXPERT
 907         default y
 908         depends on X86_32
 909         ---help---
 910           This option is required by programs like DOSEMU to run 16-bit legacy
 911           code on X86 processors. It also may be needed by software like
 912           XFree86 to initialize some video cards via BIOS. Disabling this
 913           option saves about 6k.
 914
 915 config TOSHIBA
 916         tristate "Toshiba Laptop support"
 917         depends on X86_32
 918         ---help---
 919           This adds a driver to safely access the System Management Mode of
 920           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 921           not work on models with a Phoenix BIOS. The System Management Mode
 922           is used to set the BIOS and power saving options on Toshiba portables.
 923
 924           For information on utilities to make use of this driver see the
 925           Toshiba Linux utilities web site at:
 926           <http://www.buzzard.org.uk/toshiba/>.
 927
 928           Say Y if you intend to run this kernel on a Toshiba portable.
 929           Say N otherwise.
 930
 931 config I8K
 932         tristate "Dell laptop support"
 933         select HWMON
 934         ---help---
 935           This adds a driver to safely access the System Management Mode
 936           of the CPU on the Dell Inspiron 8000. The System Management Mode
 937           is used to read cpu temperature and cooling fan status and to
 938           control the fans on the I8K portables.
 939
 940           This driver has been tested only on the Inspiron 8000 but it may
 941           also work with other Dell laptops. You can force loading on other
 942           models by passing the parameter `force=1' to the module. Use at
 943           your own risk.
 944
 945           For information on utilities to make use of this driver see the
 946           I8K Linux utilities web site at:
 947           <http://people.debian.org/~dz/i8k/>
 948
 949           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 950           Say N otherwise.
 951
 952 config X86_REBOOTFIXUPS
 953         bool "Enable X86 board specific fixups for reboot"
 954         depends on X86_32
 955         ---help---
 956           This enables chipset and/or board specific fixups to be done
 957           in order to get reboot to work correctly. This is only needed on
 958           some combinations of hardware and BIOS. The symptom, for which
 959           this config is intended, is when reboot ends with a stalled/hung
 960           system.
 961
 962           Currently, the only fixup is for the Geode machines using
 963           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 964
 965           Say Y if you want to enable the fixup. Currently, it's safe to
 966           enable this option even if you don't need it.
 967           Say N otherwise.
 968
 969 config MICROCODE
 970         tristate "/dev/cpu/microcode - microcode support"
 971         select FW_LOADER
 972         ---help---
 973           If you say Y here, you will be able to update the microcode on
 974           certain Intel and AMD processors. The Intel support is for the
 975           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 976           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 977           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 978           You will obviously need the actual microcode binary data itself
 979           which is not shipped with the Linux kernel.
 980
 981           This option selects the general module only, you need to select
 982           at least one vendor specific module as well.
 983
 984           To compile this driver as a module, choose M here: the
 985           module will be called microcode.
 986
 987 config MICROCODE_INTEL
 988         bool "Intel microcode patch loading support"
 989         depends on MICROCODE
 990         default MICROCODE
 991         select FW_LOADER
 992         ---help---
 993           This options enables microcode patch loading support for Intel
 994           processors.
 995
 996           For latest news and information on obtaining all the required
 997           Intel ingredients for this driver, check:
 998           <http://www.urbanmyth.org/microcode/>.
 999
1000 config MICROCODE_AMD
1001         bool "AMD microcode patch loading support"
1002         depends on MICROCODE
1003         select FW_LOADER
1004         ---help---
1005           If you select this option, microcode patch loading support for AMD
1006           processors will be enabled.
1007
1008 config MICROCODE_OLD_INTERFACE
1009         def_bool y
1010         depends on MICROCODE
1011
1012 config X86_MSR
1013         tristate "/dev/cpu/*/msr - Model-specific register support"
1014         ---help---
1015           This device gives privileged processes access to the x86
1016           Model-Specific Registers (MSRs).  It is a character device with
1017           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1018           MSR accesses are directed to a specific CPU on multi-processor
1019           systems.
1020
1021 config X86_CPUID
1022         tristate "/dev/cpu/*/cpuid - CPU information support"
1023         ---help---
1024           This device gives processes access to the x86 CPUID instruction to
1025           be executed on a specific processor.  It is a character device
1026           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1027           /dev/cpu/31/cpuid.
1028
1029 choice
1030         prompt "High Memory Support"
1031         default HIGHMEM64G if X86_NUMAQ
1032         default HIGHMEM4G
1033         depends on X86_32
1034
1035 config NOHIGHMEM
1036         bool "off"
1037         depends on !X86_NUMAQ
1038         ---help---
1039           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1040           However, the address space of 32-bit x86 processors is only 4
1041           Gigabytes large. That means that, if you have a large amount of
1042           physical memory, not all of it can be "permanently mapped" by the
1043           kernel. The physical memory that's not permanently mapped is called
1044           "high memory".
1045
1046           If you are compiling a kernel which will never run on a machine with
1047           more than 1 Gigabyte total physical RAM, answer "off" here (default
1048           choice and suitable for most users). This will result in a "3GB/1GB"
1049           split: 3GB are mapped so that each process sees a 3GB virtual memory
1050           space and the remaining part of the 4GB virtual memory space is used
1051           by the kernel to permanently map as much physical memory as
1052           possible.
1053
1054           If the machine has between 1 and 4 Gigabytes physical RAM, then
1055           answer "4GB" here.
1056
1057           If more than 4 Gigabytes is used then answer "64GB" here. This
1058           selection turns Intel PAE (Physical Address Extension) mode on.
1059           PAE implements 3-level paging on IA32 processors. PAE is fully
1060           supported by Linux, PAE mode is implemented on all recent Intel
1061           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1062           then the kernel will not boot on CPUs that don't support PAE!
1063
1064           The actual amount of total physical memory will either be
1065           auto detected or can be forced by using a kernel command line option
1066           such as "mem=256M". (Try "man bootparam" or see the documentation of
1067           your boot loader (lilo or loadlin) about how to pass options to the
1068           kernel at boot time.)
1069
1070           If unsure, say "off".
1071
1072 config HIGHMEM4G
1073         bool "4GB"
1074         depends on !X86_NUMAQ
1075         ---help---
1076           Select this if you have a 32-bit processor and between 1 and 4
1077           gigabytes of physical RAM.
1078
1079 config HIGHMEM64G
1080         bool "64GB"
1081         depends on !M386 && !M486
1082         select X86_PAE
1083         ---help---
1084           Select this if you have a 32-bit processor and more than 4
1085           gigabytes of physical RAM.
1086
1087 endchoice
1088
1089 choice
1090         depends on EXPERIMENTAL
1091         prompt "Memory split" if EXPERT
1092         default VMSPLIT_3G
1093         depends on X86_32
1094         ---help---
1095           Select the desired split between kernel and user memory.
1096
1097           If the address range available to the kernel is less than the
1098           physical memory installed, the remaining memory will be available
1099           as "high memory". Accessing high memory is a little more costly
1100           than low memory, as it needs to be mapped into the kernel first.
1101           Note that increasing the kernel address space limits the range
1102           available to user programs, making the address space there
1103           tighter.  Selecting anything other than the default 3G/1G split
1104           will also likely make your kernel incompatible with binary-only
1105           kernel modules.
1106
1107           If you are not absolutely sure what you are doing, leave this
1108           option alone!
1109
1110         config VMSPLIT_3G
1111                 bool "3G/1G user/kernel split"
1112         config VMSPLIT_3G_OPT
1113                 depends on !X86_PAE
1114                 bool "3G/1G user/kernel split (for full 1G low memory)"
1115         config VMSPLIT_2G
1116                 bool "2G/2G user/kernel split"
1117         config VMSPLIT_2G_OPT
1118                 depends on !X86_PAE
1119                 bool "2G/2G user/kernel split (for full 2G low memory)"
1120         config VMSPLIT_1G
1121                 bool "1G/3G user/kernel split"
1122 endchoice
1123
1124 config PAGE_OFFSET
1125         hex
1126         default 0xB0000000 if VMSPLIT_3G_OPT
1127         default 0x80000000 if VMSPLIT_2G
1128         default 0x78000000 if VMSPLIT_2G_OPT
1129         default 0x40000000 if VMSPLIT_1G
1130         default 0xC0000000
1131         depends on X86_32
1132
1133 config HIGHMEM
1134         def_bool y
1135         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1136
1137 config X86_PAE
1138         bool "PAE (Physical Address Extension) Support"
1139         depends on X86_32 && !HIGHMEM4G
1140         ---help---
1141           PAE is required for NX support, and furthermore enables
1142           larger swapspace support for non-overcommit purposes. It
1143           has the cost of more pagetable lookup overhead, and also
1144           consumes more pagetable space per process.
1145
1146 config ARCH_PHYS_ADDR_T_64BIT
1147         def_bool X86_64 || X86_PAE
1148
1149 config ARCH_DMA_ADDR_T_64BIT
1150         def_bool X86_64 || HIGHMEM64G
1151
1152 config DIRECT_GBPAGES
1153         bool "Enable 1GB pages for kernel pagetables" if EXPERT
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 AMD_NUMA
1187         def_bool y
1188         prompt "Old style AMD Opteron NUMA detection"
1189         depends on X86_64 && NUMA && PCI
1190         ---help---
1191           Enable AMD NUMA node topology detection.  You should say Y here if
1192           you have a multi processor AMD system. This uses an old method to
1193           read the NUMA configuration directly from the builtin Northbridge
1194           of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1195           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 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 HAVE_ARCH_ALLOC_REMAP
1239         def_bool y
1240         depends on X86_32 && NUMA
1241
1242 config ARCH_HAVE_MEMORY_PRESENT
1243         def_bool y
1244         depends on X86_32 && DISCONTIGMEM
1245
1246 config NEED_NODE_MEMMAP_SIZE
1247         def_bool y
1248         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1249
1250 config ARCH_FLATMEM_ENABLE
1251         def_bool y
1252         depends on X86_32 && !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_SPARSEMEM_ENABLE
1263         def_bool y
1264         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1265         select SPARSEMEM_STATIC if X86_32
1266         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1267
1268 config ARCH_SPARSEMEM_DEFAULT
1269         def_bool y
1270         depends on X86_64
1271
1272 config ARCH_SELECT_MEMORY_MODEL
1273         def_bool y
1274         depends on ARCH_SPARSEMEM_ENABLE
1275
1276 config ARCH_MEMORY_PROBE
1277         def_bool X86_64
1278         depends on MEMORY_HOTPLUG
1279
1280 config ARCH_PROC_KCORE_TEXT
1281         def_bool y
1282         depends on X86_64 && PROC_KCORE
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
1331         int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1332         default 64
1333         range 4 640
1334         ---help---
1335           Specify the amount of low memory to reserve for the BIOS.
1336
1337           The first page contains BIOS data structures that the kernel
1338           must not use, so that page must always be reserved.
1339
1340           By default we reserve the first 64K of physical RAM, as a
1341           number of BIOSes are known to corrupt that memory range
1342           during events such as suspend/resume or monitor cable
1343           insertion, so it must not be used by the kernel.
1344
1345           You can set this to 4 if you are absolutely sure that you
1346           trust the BIOS to get all its memory reservations and usages
1347           right.  If you know your BIOS have problems beyond the
1348           default 64K area, you can set this to 640 to avoid using the
1349           entire low memory range.
1350
1351           If you have doubts about the BIOS (e.g. suspend/resume does
1352           not work or there's kernel crashes after certain hardware
1353           hotplug events) then you might want to enable
1354           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1355           typical corruption patterns.
1356
1357           Leave this to the default value of 64 if you are unsure.
1358
1359 config MATH_EMULATION
1360         bool
1361         prompt "Math emulation" if X86_32
1362         ---help---
1363           Linux can emulate a math coprocessor (used for floating point
1364           operations) if you don't have one. 486DX and Pentium processors have
1365           a math coprocessor built in, 486SX and 386 do not, unless you added
1366           a 487DX or 387, respectively. (The messages during boot time can
1367           give you some hints here ["man dmesg"].) Everyone needs either a
1368           coprocessor or this emulation.
1369
1370           If you don't have a math coprocessor, you need to say Y here; if you
1371           say Y here even though you have a coprocessor, the coprocessor will
1372           be used nevertheless. (This behavior can be changed with the kernel
1373           command line option "no387", which comes handy if your coprocessor
1374           is broken. Try "man bootparam" or see the documentation of your boot
1375           loader (lilo or loadlin) about how to pass options to the kernel at
1376           boot time.) This means that it is a good idea to say Y here if you
1377           intend to use this kernel on different machines.
1378
1379           More information about the internals of the Linux math coprocessor
1380           emulation can be found in <file:arch/x86/math-emu/README>.
1381
1382           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1383           kernel, it won't hurt.
1384
1385 config MTRR
1386         def_bool y
1387         prompt "MTRR (Memory Type Range Register) support" if EXPERT
1388         ---help---
1389           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1390           the Memory Type Range Registers (MTRRs) may be used to control
1391           processor access to memory ranges. This is most useful if you have
1392           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1393           allows bus write transfers to be combined into a larger transfer
1394           before bursting over the PCI/AGP bus. This can increase performance
1395           of image write operations 2.5 times or more. Saying Y here creates a
1396           /proc/mtrr file which may be used to manipulate your processor's
1397           MTRRs. Typically the X server should use this.
1398
1399           This code has a reasonably generic interface so that similar
1400           control registers on other processors can be easily supported
1401           as well:
1402
1403           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1404           Registers (ARRs) which provide a similar functionality to MTRRs. For
1405           these, the ARRs are used to emulate the MTRRs.
1406           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1407           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1408           write-combining. All of these processors are supported by this code
1409           and it makes sense to say Y here if you have one of them.
1410
1411           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1412           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1413           can lead to all sorts of problems, so it's good to say Y here.
1414
1415           You can safely say Y even if your machine doesn't have MTRRs, you'll
1416           just add about 9 KB to your kernel.
1417
1418           See <file:Documentation/x86/mtrr.txt> for more information.
1419
1420 config MTRR_SANITIZER
1421         def_bool y
1422         prompt "MTRR cleanup support"
1423         depends on MTRR
1424         ---help---
1425           Convert MTRR layout from continuous to discrete, so X drivers can
1426           add writeback entries.
1427
1428           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1429           The largest mtrr entry size for a continuous block can be set with
1430           mtrr_chunk_size.
1431
1432           If unsure, say Y.
1433
1434 config MTRR_SANITIZER_ENABLE_DEFAULT
1435         int "MTRR cleanup enable value (0-1)"
1436         range 0 1
1437         default "0"
1438         depends on MTRR_SANITIZER
1439         ---help---
1440           Enable mtrr cleanup default value
1441
1442 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1443         int "MTRR cleanup spare reg num (0-7)"
1444         range 0 7
1445         default "1"
1446         depends on MTRR_SANITIZER
1447         ---help---
1448           mtrr cleanup spare entries default, it can be changed via
1449           mtrr_spare_reg_nr=N on the kernel command line.
1450
1451 config X86_PAT
1452         def_bool y
1453         prompt "x86 PAT support" if EXPERT
1454         depends on MTRR
1455         ---help---
1456           Use PAT attributes to setup page level cache control.
1457
1458           PATs are the modern equivalents of MTRRs and are much more
1459           flexible than MTRRs.
1460
1461           Say N here if you see bootup problems (boot crash, boot hang,
1462           spontaneous reboots) or a non-working video driver.
1463
1464           If unsure, say Y.
1465
1466 config ARCH_USES_PG_UNCACHED
1467         def_bool y
1468         depends on X86_PAT
1469
1470 config ARCH_RANDOM
1471         def_bool y
1472         prompt "x86 architectural random number generator" if EXPERT
1473         ---help---
1474           Enable the x86 architectural RDRAND instruction
1475           (Intel Bull Mountain technology) to generate random numbers.
1476           If supported, this is a high bandwidth, cryptographically
1477           secure hardware random number generator.
1478
1479 config EFI
1480         bool "EFI runtime service support"
1481         depends on ACPI
1482         ---help---
1483           This enables the kernel to use EFI runtime services that are
1484           available (such as the EFI variable services).
1485
1486           This option is only useful on systems that have EFI firmware.
1487           In addition, you should use the latest ELILO loader available
1488           at <http://elilo.sourceforge.net> in order to take advantage
1489           of EFI runtime services. However, even with this option, the
1490           resultant kernel should continue to boot on existing non-EFI
1491           platforms.
1492
1493 config SECCOMP
1494         def_bool y
1495         prompt "Enable seccomp to safely compute untrusted bytecode"
1496         ---help---
1497           This kernel feature is useful for number crunching applications
1498           that may need to compute untrusted bytecode during their
1499           execution. By using pipes or other transports made available to
1500           the process as file descriptors supporting the read/write
1501           syscalls, it's possible to isolate those applications in
1502           their own address space using seccomp. Once seccomp is
1503           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1504           and the task is only allowed to execute a few safe syscalls
1505           defined by each seccomp mode.
1506
1507           If unsure, say Y. Only embedded should say N here.
1508
1509 config CC_STACKPROTECTOR
1510         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1511         ---help---
1512           This option turns on the -fstack-protector GCC feature. This
1513           feature puts, at the beginning of functions, a canary value on
1514           the stack just before the return address, and validates
1515           the value just before actually returning.  Stack based buffer
1516           overflows (that need to overwrite this return address) now also
1517           overwrite the canary, which gets detected and the attack is then
1518           neutralized via a kernel panic.
1519
1520           This feature requires gcc version 4.2 or above, or a distribution
1521           gcc with the feature backported. Older versions are automatically
1522           detected and for those versions, this configuration option is
1523           ignored. (and a warning is printed during bootup)
1524
1525 source kernel/Kconfig.hz
1526
1527 config KEXEC
1528         bool "kexec system call"
1529         ---help---
1530           kexec is a system call that implements the ability to shutdown your
1531           current kernel, and to start another kernel.  It is like a reboot
1532           but it is independent of the system firmware.   And like a reboot
1533           you can start any kernel with it, not just Linux.
1534
1535           The name comes from the similarity to the exec system call.
1536
1537           It is an ongoing process to be certain the hardware in a machine
1538           is properly shutdown, so do not be surprised if this code does not
1539           initially work for you.  It may help to enable device hotplugging
1540           support.  As of this writing the exact hardware interface is
1541           strongly in flux, so no good recommendation can be made.
1542
1543 config CRASH_DUMP
1544         bool "kernel crash dumps"
1545         depends on X86_64 || (X86_32 && HIGHMEM)
1546         ---help---
1547           Generate crash dump after being started by kexec.
1548           This should be normally only set in special crash dump kernels
1549           which are loaded in the main kernel with kexec-tools into
1550           a specially reserved region and then later executed after
1551           a crash by kdump/kexec. The crash dump kernel must be compiled
1552           to a memory address not used by the main kernel or BIOS using
1553           PHYSICAL_START, or it must be built as a relocatable image
1554           (CONFIG_RELOCATABLE=y).
1555           For more details see Documentation/kdump/kdump.txt
1556
1557 config KEXEC_JUMP
1558         bool "kexec jump (EXPERIMENTAL)"
1559         depends on EXPERIMENTAL
1560         depends on KEXEC && HIBERNATION
1561         ---help---
1562           Jump between original kernel and kexeced kernel and invoke
1563           code in physical address mode via KEXEC
1564
1565 config PHYSICAL_START
1566         hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1567         default "0x1000000"
1568         ---help---
1569           This gives the physical address where the kernel is loaded.
1570
1571           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1572           bzImage will decompress itself to above physical address and
1573           run from there. Otherwise, bzImage will run from the address where
1574           it has been loaded by the boot loader and will ignore above physical
1575           address.
1576
1577           In normal kdump cases one does not have to set/change this option
1578           as now bzImage can be compiled as a completely relocatable image
1579           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1580           address. This option is mainly useful for the folks who don't want
1581           to use a bzImage for capturing the crash dump and want to use a
1582           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1583           to be specifically compiled to run from a specific memory area
1584           (normally a reserved region) and this option comes handy.
1585
1586           So if you are using bzImage for capturing the crash dump,
1587           leave the value here unchanged to 0x1000000 and set
1588           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1589           for capturing the crash dump change this value to start of
1590           the reserved region.  In other words, it can be set based on
1591           the "X" value as specified in the "crashkernel=YM@XM"
1592           command line boot parameter passed to the panic-ed
1593           kernel. Please take a look at Documentation/kdump/kdump.txt
1594           for more details about crash dumps.
1595
1596           Usage of bzImage for capturing the crash dump is recommended as
1597           one does not have to build two kernels. Same kernel can be used
1598           as production kernel and capture kernel. Above option should have
1599           gone away after relocatable bzImage support is introduced. But it
1600           is present because there are users out there who continue to use
1601           vmlinux for dump capture. This option should go away down the
1602           line.
1603
1604           Don't change this unless you know what you are doing.
1605
1606 config RELOCATABLE
1607         bool "Build a relocatable kernel"
1608         default y
1609         ---help---
1610           This builds a kernel image that retains relocation information
1611           so it can be loaded someplace besides the default 1MB.
1612           The relocations tend to make the kernel binary about 10% larger,
1613           but are discarded at runtime.
1614
1615           One use is for the kexec on panic case where the recovery kernel
1616           must live at a different physical address than the primary
1617           kernel.
1618
1619           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1620           it has been loaded at and the compile time physical address
1621           (CONFIG_PHYSICAL_START) is ignored.
1622
1623 # Relocation on x86-32 needs some additional build support
1624 config X86_NEED_RELOCS
1625         def_bool y
1626         depends on X86_32 && RELOCATABLE
1627
1628 config PHYSICAL_ALIGN
1629         hex "Alignment value to which kernel should be aligned" if X86_32
1630         default "0x1000000"
1631         range 0x2000 0x1000000
1632         ---help---
1633           This value puts the alignment restrictions on physical address
1634           where kernel is loaded and run from. Kernel is compiled for an
1635           address which meets above alignment restriction.
1636
1637           If bootloader loads the kernel at a non-aligned address and
1638           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1639           address aligned to above value and run from there.
1640
1641           If bootloader loads the kernel at a non-aligned address and
1642           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1643           load address and decompress itself to the address it has been
1644           compiled for and run from there. The address for which kernel is
1645           compiled already meets above alignment restrictions. Hence the
1646           end result is that kernel runs from a physical address meeting
1647           above alignment restrictions.
1648
1649           Don't change this unless you know what you are doing.
1650
1651 config HOTPLUG_CPU
1652         bool "Support for hot-pluggable CPUs"
1653         depends on SMP && HOTPLUG
1654         ---help---
1655           Say Y here to allow turning CPUs off and on. CPUs can be
1656           controlled through /sys/devices/system/cpu.
1657           ( Note: power management support will enable this option
1658             automatically on SMP systems. )
1659           Say N if you want to disable CPU hotplug.
1660
1661 config COMPAT_VDSO
1662         def_bool y
1663         prompt "Compat VDSO support"
1664         depends on X86_32 || IA32_EMULATION
1665         ---help---
1666           Map the 32-bit VDSO to the predictable old-style address too.
1667
1668           Say N here if you are running a sufficiently recent glibc
1669           version (2.3.3 or later), to remove the high-mapped
1670           VDSO mapping and to exclusively use the randomized VDSO.
1671
1672           If unsure, say Y.
1673
1674 config CMDLINE_BOOL
1675         bool "Built-in kernel command line"
1676         ---help---
1677           Allow for specifying boot arguments to the kernel at
1678           build time.  On some systems (e.g. embedded ones), it is
1679           necessary or convenient to provide some or all of the
1680           kernel boot arguments with the kernel itself (that is,
1681           to not rely on the boot loader to provide them.)
1682
1683           To compile command line arguments into the kernel,
1684           set this option to 'Y', then fill in the
1685           the boot arguments in CONFIG_CMDLINE.
1686
1687           Systems with fully functional boot loaders (i.e. non-embedded)
1688           should leave this option set to 'N'.
1689
1690 config CMDLINE
1691         string "Built-in kernel command string"
1692         depends on CMDLINE_BOOL
1693         default ""
1694         ---help---
1695           Enter arguments here that should be compiled into the kernel
1696           image and used at boot time.  If the boot loader provides a
1697           command line at boot time, it is appended to this string to
1698           form the full kernel command line, when the system boots.
1699
1700           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1701           change this behavior.
1702
1703           In most cases, the command line (whether built-in or provided
1704           by the boot loader) should specify the device for the root
1705           file system.
1706
1707 config CMDLINE_OVERRIDE
1708         bool "Built-in command line overrides boot loader arguments"
1709         depends on CMDLINE_BOOL
1710         ---help---
1711           Set this option to 'Y' to have the kernel ignore the boot loader
1712           command line, and use ONLY the built-in command line.
1713
1714           This is used to work around broken boot loaders.  This should
1715           be set to 'N' under normal conditions.
1716
1717 endmenu
1718
1719 config ARCH_ENABLE_MEMORY_HOTPLUG
1720         def_bool y
1721         depends on X86_64 || (X86_32 && HIGHMEM)
1722
1723 config ARCH_ENABLE_MEMORY_HOTREMOVE
1724         def_bool y
1725         depends on MEMORY_HOTPLUG
1726
1727 config USE_PERCPU_NUMA_NODE_ID
1728         def_bool y
1729         depends on NUMA
1730
1731 menu "Power management and ACPI options"
1732
1733 config ARCH_HIBERNATION_HEADER
1734         def_bool y
1735         depends on X86_64 && HIBERNATION
1736
1737 source "kernel/power/Kconfig"
1738
1739 source "drivers/acpi/Kconfig"
1740
1741 source "drivers/sfi/Kconfig"
1742
1743 config X86_APM_BOOT
1744         def_bool y
1745         depends on APM || APM_MODULE
1746
1747 menuconfig APM
1748         tristate "APM (Advanced Power Management) BIOS support"
1749         depends on X86_32 && PM_SLEEP
1750         ---help---
1751           APM is a BIOS specification for saving power using several different
1752           techniques. This is mostly useful for battery powered laptops with
1753           APM compliant BIOSes. If you say Y here, the system time will be
1754           reset after a RESUME operation, the /proc/apm device will provide
1755           battery status information, and user-space programs will receive
1756           notification of APM "events" (e.g. battery status change).
1757
1758           If you select "Y" here, you can disable actual use of the APM
1759           BIOS by passing the "apm=off" option to the kernel at boot time.
1760
1761           Note that the APM support is almost completely disabled for
1762           machines with more than one CPU.
1763
1764           In order to use APM, you will need supporting software. For location
1765           and more information, read <file:Documentation/power/apm-acpi.txt>
1766           and the Battery Powered Linux mini-HOWTO, available from
1767           <http://www.tldp.org/docs.html#howto>.
1768
1769           This driver does not spin down disk drives (see the hdparm(8)
1770           manpage ("man 8 hdparm") for that), and it doesn't turn off
1771           VESA-compliant "green" monitors.
1772
1773           This driver does not support the TI 4000M TravelMate and the ACER
1774           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1775           desktop machines also don't have compliant BIOSes, and this driver
1776           may cause those machines to panic during the boot phase.
1777
1778           Generally, if you don't have a battery in your machine, there isn't
1779           much point in using this driver and you should say N. If you get
1780           random kernel OOPSes or reboots that don't seem to be related to
1781           anything, try disabling/enabling this option (or disabling/enabling
1782           APM in your BIOS).
1783
1784           Some other things you should try when experiencing seemingly random,
1785           "weird" problems:
1786
1787           1) make sure that you have enough swap space and that it is
1788           enabled.
1789           2) pass the "no-hlt" option to the kernel
1790           3) switch on floating point emulation in the kernel and pass
1791           the "no387" option to the kernel
1792           4) pass the "floppy=nodma" option to the kernel
1793           5) pass the "mem=4M" option to the kernel (thereby disabling
1794           all but the first 4 MB of RAM)
1795           6) make sure that the CPU is not over clocked.
1796           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1797           8) disable the cache from your BIOS settings
1798           9) install a fan for the video card or exchange video RAM
1799           10) install a better fan for the CPU
1800           11) exchange RAM chips
1801           12) exchange the motherboard.
1802
1803           To compile this driver as a module, choose M here: the
1804           module will be called apm.
1805
1806 if APM
1807
1808 config APM_IGNORE_USER_SUSPEND
1809         bool "Ignore USER SUSPEND"
1810         ---help---
1811           This option will ignore USER SUSPEND requests. On machines with a
1812           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1813           series notebooks, it is necessary to say Y because of a BIOS bug.
1814
1815 config APM_DO_ENABLE
1816         bool "Enable PM at boot time"
1817         ---help---
1818           Enable APM features at boot time. From page 36 of the APM BIOS
1819           specification: "When disabled, the APM BIOS does not automatically
1820           power manage devices, enter the Standby State, enter the Suspend
1821           State, or take power saving steps in response to CPU Idle calls."
1822           This driver will make CPU Idle calls when Linux is idle (unless this
1823           feature is turned off -- see "Do CPU IDLE calls", below). This
1824           should always save battery power, but more complicated APM features
1825           will be dependent on your BIOS implementation. You may need to turn
1826           this option off if your computer hangs at boot time when using APM
1827           support, or if it beeps continuously instead of suspending. Turn
1828           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1829           T400CDT. This is off by default since most machines do fine without
1830           this feature.
1831
1832 config APM_CPU_IDLE
1833         bool "Make CPU Idle calls when idle"
1834         ---help---
1835           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1836           On some machines, this can activate improved power savings, such as
1837           a slowed CPU clock rate, when the machine is idle. These idle calls
1838           are made after the idle loop has run for some length of time (e.g.,
1839           333 mS). On some machines, this will cause a hang at boot time or
1840           whenever the CPU becomes idle. (On machines with more than one CPU,
1841           this option does nothing.)
1842
1843 config APM_DISPLAY_BLANK
1844         bool "Enable console blanking using APM"
1845         ---help---
1846           Enable console blanking using the APM. Some laptops can use this to
1847           turn off the LCD backlight when the screen blanker of the Linux
1848           virtual console blanks the screen. Note that this is only used by
1849           the virtual console screen blanker, and won't turn off the backlight
1850           when using the X Window system. This also doesn't have anything to
1851           do with your VESA-compliant power-saving monitor. Further, this
1852           option doesn't work for all laptops -- it might not turn off your
1853           backlight at all, or it might print a lot of errors to the console,
1854           especially if you are using gpm.
1855
1856 config APM_ALLOW_INTS
1857         bool "Allow interrupts during APM BIOS calls"
1858         ---help---
1859           Normally we disable external interrupts while we are making calls to
1860           the APM BIOS as a measure to lessen the effects of a badly behaving
1861           BIOS implementation.  The BIOS should reenable interrupts if it
1862           needs to.  Unfortunately, some BIOSes do not -- especially those in
1863           many of the newer IBM Thinkpads.  If you experience hangs when you
1864           suspend, try setting this to Y.  Otherwise, say N.
1865
1866 endif # APM
1867
1868 source "drivers/cpufreq/Kconfig"
1869
1870 source "drivers/cpuidle/Kconfig"
1871
1872 source "drivers/idle/Kconfig"
1873
1874 endmenu
1875
1876
1877 menu "Bus options (PCI etc.)"
1878
1879 config PCI
1880         bool "PCI support"
1881         default y
1882         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1883         ---help---
1884           Find out whether you have a PCI motherboard. PCI is the name of a
1885           bus system, i.e. the way the CPU talks to the other stuff inside
1886           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1887           VESA. If you have PCI, say Y, otherwise N.
1888
1889 choice
1890         prompt "PCI access mode"
1891         depends on X86_32 && PCI
1892         default PCI_GOANY
1893         ---help---
1894           On PCI systems, the BIOS can be used to detect the PCI devices and
1895           determine their configuration. However, some old PCI motherboards
1896           have BIOS bugs and may crash if this is done. Also, some embedded
1897           PCI-based systems don't have any BIOS at all. Linux can also try to
1898           detect the PCI hardware directly without using the BIOS.
1899
1900           With this option, you can specify how Linux should detect the
1901           PCI devices. If you choose "BIOS", the BIOS will be used,
1902           if you choose "Direct", the BIOS won't be used, and if you
1903           choose "MMConfig", then PCI Express MMCONFIG will be used.
1904           If you choose "Any", the kernel will try MMCONFIG, then the
1905           direct access method and falls back to the BIOS if that doesn't
1906           work. If unsure, go with the default, which is "Any".
1907
1908 config PCI_GOBIOS
1909         bool "BIOS"
1910
1911 config PCI_GOMMCONFIG
1912         bool "MMConfig"
1913
1914 config PCI_GODIRECT
1915         bool "Direct"
1916
1917 config PCI_GOOLPC
1918         bool "OLPC XO-1"
1919         depends on OLPC
1920
1921 config PCI_GOANY
1922         bool "Any"
1923
1924 endchoice
1925
1926 config PCI_BIOS
1927         def_bool y
1928         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1929
1930 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1931 config PCI_DIRECT
1932         def_bool y
1933         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
1934
1935 config PCI_MMCONFIG
1936         def_bool y
1937         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1938
1939 config PCI_OLPC
1940         def_bool y
1941         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1942
1943 config PCI_XEN
1944         def_bool y
1945         depends on PCI && XEN
1946         select SWIOTLB_XEN
1947
1948 config PCI_DOMAINS
1949         def_bool y
1950         depends on PCI
1951
1952 config PCI_MMCONFIG
1953         bool "Support mmconfig PCI config space access"
1954         depends on X86_64 && PCI && ACPI
1955
1956 config PCI_CNB20LE_QUIRK
1957         bool "Read CNB20LE Host Bridge Windows" if EXPERT
1958         default n
1959         depends on PCI && EXPERIMENTAL
1960         help
1961           Read the PCI windows out of the CNB20LE host bridge. This allows
1962           PCI hotplug to work on systems with the CNB20LE chipset which do
1963           not have ACPI.
1964
1965           There's no public spec for this chipset, and this functionality
1966           is known to be incomplete.
1967
1968           You should say N unless you know you need this.
1969
1970 source "drivers/pci/pcie/Kconfig"
1971
1972 source "drivers/pci/Kconfig"
1973
1974 # x86_64 have no ISA slots, but can have ISA-style DMA.
1975 config ISA_DMA_API
1976         bool "ISA-style DMA support" if (X86_64 && EXPERT)
1977         default y
1978         help
1979           Enables ISA-style DMA support for devices requiring such controllers.
1980           If unsure, say Y.
1981
1982 if X86_32
1983
1984 config ISA
1985         bool "ISA support"
1986         ---help---
1987           Find out whether you have ISA slots on your motherboard.  ISA is the
1988           name of a bus system, i.e. the way the CPU talks to the other stuff
1989           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1990           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1991           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1992
1993 config EISA
1994         bool "EISA support"
1995         depends on ISA
1996         ---help---
1997           The Extended Industry Standard Architecture (EISA) bus was
1998           developed as an open alternative to the IBM MicroChannel bus.
1999
2000           The EISA bus provided some of the features of the IBM MicroChannel
2001           bus while maintaining backward compatibility with cards made for
2002           the older ISA bus.  The EISA bus saw limited use between 1988 and
2003           1995 when it was made obsolete by the PCI bus.
2004
2005           Say Y here if you are building a kernel for an EISA-based machine.
2006
2007           Otherwise, say N.
2008
2009 source "drivers/eisa/Kconfig"
2010
2011 config MCA
2012         bool "MCA support"
2013         ---help---
2014           MicroChannel Architecture is found in some IBM PS/2 machines and
2015           laptops.  It is a bus system similar to PCI or ISA. See
2016           <file:Documentation/mca.txt> (and especially the web page given
2017           there) before attempting to build an MCA bus kernel.
2018
2019 source "drivers/mca/Kconfig"
2020
2021 config SCx200
2022         tristate "NatSemi SCx200 support"
2023         ---help---
2024           This provides basic support for National Semiconductor's
2025           (now AMD's) Geode processors.  The driver probes for the
2026           PCI-IDs of several on-chip devices, so its a good dependency
2027           for other scx200_* drivers.
2028
2029           If compiled as a module, the driver is named scx200.
2030
2031 config SCx200HR_TIMER
2032         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2033         depends on SCx200
2034         default y
2035         ---help---
2036           This driver provides a clocksource built upon the on-chip
2037           27MHz high-resolution timer.  Its also a workaround for
2038           NSC Geode SC-1100's buggy TSC, which loses time when the
2039           processor goes idle (as is done by the scheduler).  The
2040           other workaround is idle=poll boot option.
2041
2042 config OLPC
2043         bool "One Laptop Per Child support"
2044         depends on !X86_PAE
2045         select GPIOLIB
2046         select OF
2047         select OF_PROMTREE
2048         ---help---
2049           Add support for detecting the unique features of the OLPC
2050           XO hardware.
2051
2052 config OLPC_XO1_PM
2053         bool "OLPC XO-1 Power Management"
2054         depends on OLPC && MFD_CS5535 && PM_SLEEP
2055         select MFD_CORE
2056         ---help---
2057           Add support for poweroff and suspend of the OLPC XO-1 laptop.
2058
2059 config OLPC_XO1_RTC
2060         bool "OLPC XO-1 Real Time Clock"
2061         depends on OLPC_XO1_PM && RTC_DRV_CMOS
2062         ---help---
2063           Add support for the XO-1 real time clock, which can be used as a
2064           programmable wakeup source.
2065
2066 config OLPC_XO1_SCI
2067         bool "OLPC XO-1 SCI extras"
2068         depends on OLPC && OLPC_XO1_PM
2069         select POWER_SUPPLY
2070         select GPIO_CS5535
2071         select MFD_CORE
2072         ---help---
2073           Add support for SCI-based features of the OLPC XO-1 laptop:
2074            - EC-driven system wakeups
2075            - Power button
2076            - Ebook switch
2077            - Lid switch
2078            - AC adapter status updates
2079            - Battery status updates
2080
2081 config OLPC_XO15_SCI
2082         bool "OLPC XO-1.5 SCI extras"
2083         depends on OLPC && ACPI
2084         select POWER_SUPPLY
2085         ---help---
2086           Add support for SCI-based features of the OLPC XO-1.5 laptop:
2087            - EC-driven system wakeups
2088            - AC adapter status updates
2089            - Battery status updates
2090
2091 config ALIX
2092         bool "PCEngines ALIX System Support (LED setup)"
2093         select GPIOLIB
2094         ---help---
2095           This option enables system support for the PCEngines ALIX.
2096           At present this just sets up LEDs for GPIO control on
2097           ALIX2/3/6 boards.  However, other system specific setup should
2098           get added here.
2099
2100           Note: You must still enable the drivers for GPIO and LED support
2101           (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2102
2103           Note: You have to set alix.force=1 for boards with Award BIOS.
2104
2105 endif # X86_32
2106
2107 config AMD_NB
2108         def_bool y
2109         depends on CPU_SUP_AMD && PCI
2110
2111 source "drivers/pcmcia/Kconfig"
2112
2113 source "drivers/pci/hotplug/Kconfig"
2114
2115 config RAPIDIO
2116         bool "RapidIO support"
2117         depends on PCI
2118         default n
2119         help
2120           If you say Y here, the kernel will include drivers and
2121           infrastructure code to support RapidIO interconnect devices.
2122
2123 source "drivers/rapidio/Kconfig"
2124
2125 endmenu
2126
2127
2128 menu "Executable file formats / Emulations"
2129
2130 source "fs/Kconfig.binfmt"
2131
2132 config IA32_EMULATION
2133         bool "IA32 Emulation"
2134         depends on X86_64
2135         select COMPAT_BINFMT_ELF
2136         ---help---
2137           Include code to run 32-bit programs under a 64-bit kernel. You should
2138           likely turn this on, unless you're 100% sure that you don't have any
2139           32-bit programs left.
2140
2141 config IA32_AOUT
2142         tristate "IA32 a.out support"
2143         depends on IA32_EMULATION
2144         ---help---
2145           Support old a.out binaries in the 32bit emulation.
2146
2147 config COMPAT
2148         def_bool y
2149         depends on IA32_EMULATION
2150
2151 config COMPAT_FOR_U64_ALIGNMENT
2152         def_bool COMPAT
2153         depends on X86_64
2154
2155 config SYSVIPC_COMPAT
2156         def_bool y
2157         depends on COMPAT && SYSVIPC
2158
2159 config KEYS_COMPAT
2160         bool
2161         depends on COMPAT && KEYS
2162         default y
2163
2164 endmenu
2165
2166
2167 config HAVE_ATOMIC_IOMAP
2168         def_bool y
2169         depends on X86_32
2170
2171 config HAVE_TEXT_POKE_SMP
2172         bool
2173         select STOP_MACHINE if SMP
2174
2175 source "net/Kconfig"
2176
2177 source "drivers/Kconfig"
2178
2179 source "drivers/firmware/Kconfig"
2180
2181 source "fs/Kconfig"
2182
2183 source "arch/x86/Kconfig.debug"
2184
2185 source "security/Kconfig"
2186
2187 source "crypto/Kconfig"
2188
2189 source "arch/x86/kvm/Kconfig"
2190
2191 source "lib/Kconfig"