arch/x86/Kconfig

   1 # x86 configuration
   2 mainmenu "Linux Kernel Configuration for x86"
   3
   4 # Select 32 or 64 bit
   5 config 64BIT
   6         bool "64-bit kernel" if ARCH = "x86"
   7         default ARCH = "x86_64"
   8         ---help---
   9           Say yes to build a 64-bit kernel - formerly known as x86_64
  10           Say no to build a 32-bit kernel - formerly known as i386
  11
  12 config X86_32
  13         def_bool !64BIT
  14
  15 config X86_64
  16         def_bool 64BIT
  17
  18 ### Arch settings
  19 config X86
  20         def_bool y
  21         select HAVE_AOUT if X86_32
  22         select HAVE_READQ
  23         select HAVE_WRITEQ
  24         select HAVE_UNSTABLE_SCHED_CLOCK
  25         select HAVE_IDE
  26         select HAVE_OPROFILE
  27         select HAVE_PERF_EVENTS if (!M386 && !M486)
  28         select HAVE_IOREMAP_PROT
  29         select HAVE_KPROBES
  30         select ARCH_WANT_OPTIONAL_GPIOLIB
  31         select ARCH_WANT_FRAME_POINTERS
  32         select HAVE_DMA_ATTRS
  33         select HAVE_KRETPROBES
  34         select HAVE_FTRACE_MCOUNT_RECORD
  35         select HAVE_DYNAMIC_FTRACE
  36         select HAVE_FUNCTION_TRACER
  37         select HAVE_FUNCTION_GRAPH_TRACER
  38         select HAVE_FUNCTION_GRAPH_FP_TEST
  39         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
  40         select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
  41         select HAVE_SYSCALL_TRACEPOINTS
  42         select HAVE_KVM
  43         select HAVE_ARCH_KGDB
  44         select HAVE_ARCH_TRACEHOOK
  45         select HAVE_GENERIC_DMA_COHERENT if X86_32
  46         select HAVE_EFFICIENT_UNALIGNED_ACCESS
  47         select USER_STACKTRACE_SUPPORT
  48         select HAVE_REGS_AND_STACK_ACCESS_API
  49         select HAVE_DMA_API_DEBUG
  50         select HAVE_KERNEL_GZIP
  51         select HAVE_KERNEL_BZIP2
  52         select HAVE_KERNEL_LZMA
  53         select HAVE_KERNEL_LZO
  54         select HAVE_HW_BREAKPOINT
  55         select PERF_EVENTS
  56         select ANON_INODES
  57         select HAVE_ARCH_KMEMCHECK
  58         select HAVE_USER_RETURN_NOTIFIER
  59
  60 config OUTPUT_FORMAT
  61         string
  62         default "elf32-i386" if X86_32
  63         default "elf64-x86-64" if X86_64
  64
  65 config ARCH_DEFCONFIG
  66         string
  67         default "arch/x86/configs/i386_defconfig" if X86_32
  68         default "arch/x86/configs/x86_64_defconfig" if X86_64
  69
  70 config GENERIC_TIME
  71         def_bool y
  72
  73 config GENERIC_CMOS_UPDATE
  74         def_bool y
  75
  76 config CLOCKSOURCE_WATCHDOG
  77         def_bool y
  78
  79 config GENERIC_CLOCKEVENTS
  80         def_bool y
  81
  82 config GENERIC_CLOCKEVENTS_BROADCAST
  83         def_bool y
  84         depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
  85
  86 config LOCKDEP_SUPPORT
  87         def_bool y
  88
  89 config STACKTRACE_SUPPORT
  90         def_bool y
  91
  92 config HAVE_LATENCYTOP_SUPPORT
  93         def_bool y
  94
  95 config MMU
  96         def_bool y
  97
  98 config ZONE_DMA
  99         def_bool y
 100
 101 config SBUS
 102         bool
 103
 104 config GENERIC_ISA_DMA
 105         def_bool y
 106
 107 config GENERIC_IOMAP
 108         def_bool y
 109
 110 config GENERIC_BUG
 111         def_bool y
 112         depends on BUG
 113         select GENERIC_BUG_RELATIVE_POINTERS if X86_64
 114
 115 config GENERIC_BUG_RELATIVE_POINTERS
 116         bool
 117
 118 config GENERIC_HWEIGHT
 119         def_bool y
 120
 121 config GENERIC_GPIO
 122         bool
 123
 124 config ARCH_MAY_HAVE_PC_FDC
 125         def_bool y
 126
 127 config RWSEM_GENERIC_SPINLOCK
 128         def_bool !X86_XADD
 129
 130 config RWSEM_XCHGADD_ALGORITHM
 131         def_bool X86_XADD
 132
 133 config ARCH_HAS_CPU_IDLE_WAIT
 134         def_bool y
 135
 136 config GENERIC_CALIBRATE_DELAY
 137         def_bool y
 138
 139 config GENERIC_TIME_VSYSCALL
 140         bool
 141         default X86_64
 142
 143 config ARCH_HAS_CPU_RELAX
 144         def_bool y
 145
 146 config ARCH_HAS_DEFAULT_IDLE
 147         def_bool y
 148
 149 config ARCH_HAS_CACHE_LINE_SIZE
 150         def_bool y
 151
 152 config HAVE_SETUP_PER_CPU_AREA
 153         def_bool y
 154
 155 config NEED_PER_CPU_EMBED_FIRST_CHUNK
 156         def_bool y
 157
 158 config NEED_PER_CPU_PAGE_FIRST_CHUNK
 159         def_bool y
 160
 161 config HAVE_CPUMASK_OF_CPU_MAP
 162         def_bool X86_64_SMP
 163
 164 config ARCH_HIBERNATION_POSSIBLE
 165         def_bool y
 166
 167 config ARCH_SUSPEND_POSSIBLE
 168         def_bool y
 169
 170 config ZONE_DMA32
 171         bool
 172         default X86_64
 173
 174 config ARCH_POPULATES_NODE_MAP
 175         def_bool y
 176
 177 config AUDIT_ARCH
 178         bool
 179         default X86_64
 180
 181 config ARCH_SUPPORTS_OPTIMIZED_INLINING
 182         def_bool y
 183
 184 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 185         def_bool y
 186
 187 config HAVE_EARLY_RES
 188         def_bool y
 189
 190 config HAVE_INTEL_TXT
 191         def_bool y
 192         depends on EXPERIMENTAL && DMAR && ACPI
 193
 194 # Use the generic interrupt handling code in kernel/irq/:
 195 config GENERIC_HARDIRQS
 196         bool
 197         default y
 198
 199 config GENERIC_HARDIRQS_NO__DO_IRQ
 200        def_bool y
 201
 202 config GENERIC_IRQ_PROBE
 203         bool
 204         default y
 205
 206 config GENERIC_PENDING_IRQ
 207         bool
 208         depends on GENERIC_HARDIRQS && SMP
 209         default y
 210
 211 config USE_GENERIC_SMP_HELPERS
 212         def_bool y
 213         depends on SMP
 214
 215 config X86_32_SMP
 216         def_bool y
 217         depends on X86_32 && SMP
 218
 219 config X86_64_SMP
 220         def_bool y
 221         depends on X86_64 && SMP
 222
 223 config X86_HT
 224         bool
 225         depends on SMP
 226         default y
 227
 228 config X86_TRAMPOLINE
 229         bool
 230         depends on SMP || (64BIT && ACPI_SLEEP)
 231         default y
 232
 233 config X86_32_LAZY_GS
 234         def_bool y
 235         depends on X86_32 && !CC_STACKPROTECTOR
 236
 237 config KTIME_SCALAR
 238         def_bool X86_32
 239 source "init/Kconfig"
 240 source "kernel/Kconfig.freezer"
 241
 242 menu "Processor type and features"
 243
 244 source "kernel/time/Kconfig"
 245
 246 config SMP
 247         bool "Symmetric multi-processing support"
 248         ---help---
 249           This enables support for systems with more than one CPU. If you have
 250           a system with only one CPU, like most personal computers, say N. If
 251           you have a system with more than one CPU, say Y.
 252
 253           If you say N here, the kernel will run on single and multiprocessor
 254           machines, but will use only one CPU of a multiprocessor machine. If
 255           you say Y here, the kernel will run on many, but not all,
 256           singleprocessor machines. On a singleprocessor machine, the kernel
 257           will run faster if you say N here.
 258
 259           Note that if you say Y here and choose architecture "586" or
 260           "Pentium" under "Processor family", the kernel will not work on 486
 261           architectures. Similarly, multiprocessor kernels for the "PPro"
 262           architecture may not work on all Pentium based boards.
 263
 264           People using multiprocessor machines who say Y here should also say
 265           Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
 266           Management" code will be disabled if you say Y here.
 267
 268           See also <file:Documentation/i386/IO-APIC.txt>,
 269           <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
 270           <http://www.tldp.org/docs.html#howto>.
 271
 272           If you don't know what to do here, say N.
 273
 274 config X86_X2APIC
 275         bool "Support x2apic"
 276         depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
 277         ---help---
 278           This enables x2apic support on CPUs that have this feature.
 279
 280           This allows 32-bit apic IDs (so it can support very large systems),
 281           and accesses the local apic via MSRs not via mmio.
 282
 283           If you don't know what to do here, say N.
 284
 285 config SPARSE_IRQ
 286         bool "Support sparse irq numbering"
 287         depends on PCI_MSI || HT_IRQ
 288         ---help---
 289           This enables support for sparse irqs. This is useful for distro
 290           kernels that want to define a high CONFIG_NR_CPUS value but still
 291           want to have low kernel memory footprint on smaller machines.
 292
 293           ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread
 294             out the irq_desc[] array in a more NUMA-friendly way. )
 295
 296           If you don't know what to do here, say N.
 297
 298 config NUMA_IRQ_DESC
 299         def_bool y
 300         depends on SPARSE_IRQ && NUMA
 301
 302 config X86_MPPARSE
 303         bool "Enable MPS table" if ACPI
 304         default y
 305         depends on X86_LOCAL_APIC
 306         ---help---
 307           For old smp systems that do not have proper acpi support. Newer systems
 308           (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 309
 310 config X86_BIGSMP
 311         bool "Support for big SMP systems with more than 8 CPUs"
 312         depends on X86_32 && SMP
 313         ---help---
 314           This option is needed for the systems that have more than 8 CPUs
 315
 316 if X86_32
 317 config X86_EXTENDED_PLATFORM
 318         bool "Support for extended (non-PC) x86 platforms"
 319         default y
 320         ---help---
 321           If you disable this option then the kernel will only support
 322           standard PC platforms. (which covers the vast majority of
 323           systems out there.)
 324
 325           If you enable this option then you'll be able to select support
 326           for the following (non-PC) 32 bit x86 platforms:
 327                 AMD Elan
 328                 NUMAQ (IBM/Sequent)
 329                 RDC R-321x SoC
 330                 SGI 320/540 (Visual Workstation)
 331                 Summit/EXA (IBM x440)
 332                 Unisys ES7000 IA32 series
 333                 Moorestown MID devices
 334
 335           If you have one of these systems, or if you want to build a
 336           generic distribution kernel, say Y here - otherwise say N.
 337 endif
 338
 339 if X86_64
 340 config X86_EXTENDED_PLATFORM
 341         bool "Support for extended (non-PC) x86 platforms"
 342         default y
 343         ---help---
 344           If you disable this option then the kernel will only support
 345           standard PC platforms. (which covers the vast majority of
 346           systems out there.)
 347
 348           If you enable this option then you'll be able to select support
 349           for the following (non-PC) 64 bit x86 platforms:
 350                 ScaleMP vSMP
 351                 SGI Ultraviolet
 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 # This is an alphabetically sorted list of 64 bit extended platforms
 357 # Please maintain the alphabetic order if and when there are additions
 358
 359 config X86_VSMP
 360         bool "ScaleMP vSMP"
 361         select PARAVIRT
 362         depends on X86_64 && PCI
 363         depends on X86_EXTENDED_PLATFORM
 364         ---help---
 365           Support for ScaleMP vSMP systems.  Say 'Y' here if this kernel is
 366           supposed to run on these EM64T-based machines.  Only choose this option
 367           if you have one of these machines.
 368
 369 config X86_UV
 370         bool "SGI Ultraviolet"
 371         depends on X86_64
 372         depends on X86_EXTENDED_PLATFORM
 373         depends on NUMA
 374         depends on X86_X2APIC
 375         ---help---
 376           This option is needed in order to support SGI Ultraviolet systems.
 377           If you don't have one of these, you should say N here.
 378
 379 # Following is an alphabetically sorted list of 32 bit extended platforms
 380 # Please maintain the alphabetic order if and when there are additions
 381
 382 config X86_ELAN
 383         bool "AMD Elan"
 384         depends on X86_32
 385         depends on X86_EXTENDED_PLATFORM
 386         ---help---
 387           Select this for an AMD Elan processor.
 388
 389           Do not use this option for K6/Athlon/Opteron processors!
 390
 391           If unsure, choose "PC-compatible" instead.
 392
 393 config X86_MRST
 394        bool "Moorestown MID platform"
 395         depends on X86_32
 396         depends on X86_EXTENDED_PLATFORM
 397         ---help---
 398           Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
 399           Internet Device(MID) platform. Moorestown consists of two chips:
 400           Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
 401           Unlike standard x86 PCs, Moorestown does not have many legacy devices
 402           nor standard legacy replacement devices/features. e.g. Moorestown does
 403           not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
 404
 405 config X86_RDC321X
 406         bool "RDC R-321x SoC"
 407         depends on X86_32
 408         depends on X86_EXTENDED_PLATFORM
 409         select M486
 410         select X86_REBOOTFIXUPS
 411         ---help---
 412           This option is needed for RDC R-321x system-on-chip, also known
 413           as R-8610-(G).
 414           If you don't have one of these chips, you should say N here.
 415
 416 config X86_32_NON_STANDARD
 417         bool "Support non-standard 32-bit SMP architectures"
 418         depends on X86_32 && SMP
 419         depends on X86_EXTENDED_PLATFORM
 420         ---help---
 421           This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
 422           subarchitectures.  It is intended for a generic binary kernel.
 423           if you select them all, kernel will probe it one by one. and will
 424           fallback to default.
 425
 426 # Alphabetically sorted list of Non standard 32 bit platforms
 427
 428 config X86_NUMAQ
 429         bool "NUMAQ (IBM/Sequent)"
 430         depends on X86_32_NON_STANDARD
 431         select NUMA
 432         select X86_MPPARSE
 433         ---help---
 434           This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
 435           NUMA multiquad box. This changes the way that processors are
 436           bootstrapped, and uses Clustered Logical APIC addressing mode instead
 437           of Flat Logical.  You will need a new lynxer.elf file to flash your
 438           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 439
 440 config X86_SUPPORTS_MEMORY_FAILURE
 441         bool
 442         # MCE code calls memory_failure():
 443         depends on X86_MCE
 444         # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
 445         depends on !X86_NUMAQ
 446         # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
 447         depends on X86_64 || !SPARSEMEM
 448         select ARCH_SUPPORTS_MEMORY_FAILURE
 449         default y
 450
 451 config X86_VISWS
 452         bool "SGI 320/540 (Visual Workstation)"
 453         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
 454         depends on X86_32_NON_STANDARD
 455         ---help---
 456           The SGI Visual Workstation series is an IA32-based workstation
 457           based on SGI systems chips with some legacy PC hardware attached.
 458
 459           Say Y here to create a kernel to run on the SGI 320 or 540.
 460
 461           A kernel compiled for the Visual Workstation will run on general
 462           PCs as well. See <file:Documentation/sgi-visws.txt> for details.
 463
 464 config X86_SUMMIT
 465         bool "Summit/EXA (IBM x440)"
 466         depends on X86_32_NON_STANDARD
 467         ---help---
 468           This option is needed for IBM systems that use the Summit/EXA chipset.
 469           In particular, it is needed for the x440.
 470
 471 config X86_ES7000
 472         bool "Unisys ES7000 IA32 series"
 473         depends on X86_32_NON_STANDARD && X86_BIGSMP
 474         ---help---
 475           Support for Unisys ES7000 systems.  Say 'Y' here if this kernel is
 476           supposed to run on an IA32-based Unisys ES7000 system.
 477
 478 config SCHED_OMIT_FRAME_POINTER
 479         def_bool y
 480         prompt "Single-depth WCHAN output"
 481         depends on X86
 482         ---help---
 483           Calculate simpler /proc/<PID>/wchan values. If this option
 484           is disabled then wchan values will recurse back to the
 485           caller function. This provides more accurate wchan values,
 486           at the expense of slightly more scheduling overhead.
 487
 488           If in doubt, say "Y".
 489
 490 menuconfig PARAVIRT_GUEST
 491         bool "Paravirtualized guest support"
 492         ---help---
 493           Say Y here to get to see options related to running Linux under
 494           various hypervisors.  This option alone does not add any kernel code.
 495
 496           If you say N, all options in this submenu will be skipped and disabled.
 497
 498 if PARAVIRT_GUEST
 499
 500 source "arch/x86/xen/Kconfig"
 501
 502 config VMI
 503         bool "VMI Guest support (DEPRECATED)"
 504         select PARAVIRT
 505         depends on X86_32
 506         ---help---
 507           VMI provides a paravirtualized interface to the VMware ESX server
 508           (it could be used by other hypervisors in theory too, but is not
 509           at the moment), by linking the kernel to a GPL-ed ROM module
 510           provided by the hypervisor.
 511
 512           As of September 2009, VMware has started a phased retirement
 513           of this feature from VMware's products. Please see
 514           feature-removal-schedule.txt for details.  If you are
 515           planning to enable this option, please note that you cannot
 516           live migrate a VMI enabled VM to a future VMware product,
 517           which doesn't support VMI. So if you expect your kernel to
 518           seamlessly migrate to newer VMware products, keep this
 519           disabled.
 520
 521 config KVM_CLOCK
 522         bool "KVM paravirtualized clock"
 523         select PARAVIRT
 524         select PARAVIRT_CLOCK
 525         ---help---
 526           Turning on this option will allow you to run a paravirtualized clock
 527           when running over the KVM hypervisor. Instead of relying on a PIT
 528           (or probably other) emulation by the underlying device model, the host
 529           provides the guest with timing infrastructure such as time of day, and
 530           system time
 531
 532 config KVM_GUEST
 533         bool "KVM Guest support"
 534         select PARAVIRT
 535         ---help---
 536           This option enables various optimizations for running under the KVM
 537           hypervisor.
 538
 539 source "arch/x86/lguest/Kconfig"
 540
 541 config PARAVIRT
 542         bool "Enable paravirtualization code"
 543         ---help---
 544           This changes the kernel so it can modify itself when it is run
 545           under a hypervisor, potentially improving performance significantly
 546           over full virtualization.  However, when run without a hypervisor
 547           the kernel is theoretically slower and slightly larger.
 548
 549 config PARAVIRT_SPINLOCKS
 550         bool "Paravirtualization layer for spinlocks"
 551         depends on PARAVIRT && SMP && EXPERIMENTAL
 552         ---help---
 553           Paravirtualized spinlocks allow a pvops backend to replace the
 554           spinlock implementation with something virtualization-friendly
 555           (for example, block the virtual CPU rather than spinning).
 556
 557           Unfortunately the downside is an up to 5% performance hit on
 558           native kernels, with various workloads.
 559
 560           If you are unsure how to answer this question, answer N.
 561
 562 config PARAVIRT_CLOCK
 563         bool
 564         default n
 565
 566 endif
 567
 568 config PARAVIRT_DEBUG
 569         bool "paravirt-ops debugging"
 570         depends on PARAVIRT && DEBUG_KERNEL
 571         ---help---
 572           Enable to debug paravirt_ops internals.  Specifically, BUG if
 573           a paravirt_op is missing when it is called.
 574
 575 config NO_BOOTMEM
 576         default y
 577         bool "Disable Bootmem code"
 578         ---help---
 579           Use early_res directly instead of bootmem before slab is ready.
 580                 - allocator (buddy) [generic]
 581                 - early allocator (bootmem) [generic]
 582                 - very early allocator (reserve_early*()) [x86]
 583                 - very very early allocator (early brk model) [x86]
 584           So reduce one layer between early allocator to final allocator
 585
 586
 587 config MEMTEST
 588         bool "Memtest"
 589         ---help---
 590           This option adds a kernel parameter 'memtest', which allows memtest
 591           to be set.
 592                 memtest=0, mean disabled; -- default
 593                 memtest=1, mean do 1 test pattern;
 594                 ...
 595                 memtest=4, mean do 4 test patterns.
 596           If you are unsure how to answer this question, answer N.
 597
 598 config X86_SUMMIT_NUMA
 599         def_bool y
 600         depends on X86_32 && NUMA && X86_32_NON_STANDARD
 601
 602 config X86_CYCLONE_TIMER
 603         def_bool y
 604         depends on X86_32_NON_STANDARD
 605
 606 source "arch/x86/Kconfig.cpu"
 607
 608 config HPET_TIMER
 609         def_bool X86_64
 610         prompt "HPET Timer Support" if X86_32
 611         ---help---
 612           Use the IA-PC HPET (High Precision Event Timer) to manage
 613           time in preference to the PIT and RTC, if a HPET is
 614           present.
 615           HPET is the next generation timer replacing legacy 8254s.
 616           The HPET provides a stable time base on SMP
 617           systems, unlike the TSC, but it is more expensive to access,
 618           as it is off-chip.  You can find the HPET spec at
 619           <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
 620
 621           You can safely choose Y here.  However, HPET will only be
 622           activated if the platform and the BIOS support this feature.
 623           Otherwise the 8254 will be used for timing services.
 624
 625           Choose N to continue using the legacy 8254 timer.
 626
 627 config HPET_EMULATE_RTC
 628         def_bool y
 629         depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
 630
 631 # Mark as embedded because too many people got it wrong.
 632 # The code disables itself when not needed.
 633 config DMI
 634         default y
 635         bool "Enable DMI scanning" if EMBEDDED
 636         ---help---
 637           Enabled scanning of DMI to identify machine quirks. Say Y
 638           here unless you have verified that your setup is not
 639           affected by entries in the DMI blacklist. Required by PNP
 640           BIOS code.
 641
 642 config GART_IOMMU
 643         bool "GART IOMMU support" if EMBEDDED
 644         default y
 645         select SWIOTLB
 646         depends on X86_64 && PCI
 647         ---help---
 648           Support for full DMA access of devices with 32bit memory access only
 649           on systems with more than 3GB. This is usually needed for USB,
 650           sound, many IDE/SATA chipsets and some other devices.
 651           Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
 652           based hardware IOMMU and a software bounce buffer based IOMMU used
 653           on Intel systems and as fallback.
 654           The code is only active when needed (enough memory and limited
 655           device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
 656           too.
 657
 658 config CALGARY_IOMMU
 659         bool "IBM Calgary IOMMU support"
 660         select SWIOTLB
 661         depends on X86_64 && PCI && EXPERIMENTAL
 662         ---help---
 663           Support for hardware IOMMUs in IBM's xSeries x366 and x460
 664           systems. Needed to run systems with more than 3GB of memory
 665           properly with 32-bit PCI devices that do not support DAC
 666           (Double Address Cycle). Calgary also supports bus level
 667           isolation, where all DMAs pass through the IOMMU.  This
 668           prevents them from going anywhere except their intended
 669           destination. This catches hard-to-find kernel bugs and
 670           mis-behaving drivers and devices that do not use the DMA-API
 671           properly to set up their DMA buffers.  The IOMMU can be
 672           turned off at boot time with the iommu=off parameter.
 673           Normally the kernel will make the right choice by itself.
 674           If unsure, say Y.
 675
 676 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 677         def_bool y
 678         prompt "Should Calgary be enabled by default?"
 679         depends on CALGARY_IOMMU
 680         ---help---
 681           Should Calgary be enabled by default? if you choose 'y', Calgary
 682           will be used (if it exists). If you choose 'n', Calgary will not be
 683           used even if it exists. If you choose 'n' and would like to use
 684           Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 685           If unsure, say Y.
 686
 687 config AMD_IOMMU
 688         bool "AMD IOMMU support"
 689         select SWIOTLB
 690         select PCI_MSI
 691         depends on X86_64 && PCI && ACPI
 692         ---help---
 693           With this option you can enable support for AMD IOMMU hardware in
 694           your system. An IOMMU is a hardware component which provides
 695           remapping of DMA memory accesses from devices. With an AMD IOMMU you
 696           can isolate the the DMA memory of different devices and protect the
 697           system from misbehaving device drivers or hardware.
 698
 699           You can find out if your system has an AMD IOMMU if you look into
 700           your BIOS for an option to enable it or if you have an IVRS ACPI
 701           table.
 702
 703 config AMD_IOMMU_STATS
 704         bool "Export AMD IOMMU statistics to debugfs"
 705         depends on AMD_IOMMU
 706         select DEBUG_FS
 707         ---help---
 708           This option enables code in the AMD IOMMU driver to collect various
 709           statistics about whats happening in the driver and exports that
 710           information to userspace via debugfs.
 711           If unsure, say N.
 712
 713 # need this always selected by IOMMU for the VIA workaround
 714 config SWIOTLB
 715         def_bool y if X86_64
 716         ---help---
 717           Support for software bounce buffers used on x86-64 systems
 718           which don't have a hardware IOMMU (e.g. the current generation
 719           of Intel's x86-64 CPUs). Using this PCI devices which can only
 720           access 32-bits of memory can be used on systems with more than
 721           3 GB of memory. If unsure, say Y.
 722
 723 config IOMMU_HELPER
 724         def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
 725
 726 config IOMMU_API
 727         def_bool (AMD_IOMMU || DMAR)
 728
 729 config MAXSMP
 730         bool "Configure Maximum number of SMP Processors and NUMA Nodes"
 731         depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
 732         select CPUMASK_OFFSTACK
 733         default n
 734         ---help---
 735           Configure maximum number of CPUS and NUMA Nodes for this architecture.
 736           If unsure, say N.
 737
 738 config NR_CPUS
 739         int "Maximum number of CPUs" if SMP && !MAXSMP
 740         range 2 8 if SMP && X86_32 && !X86_BIGSMP
 741         range 2 512 if SMP && !MAXSMP
 742         default "1" if !SMP
 743         default "4096" if MAXSMP
 744         default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
 745         default "8" if SMP
 746         ---help---
 747           This allows you to specify the maximum number of CPUs which this
 748           kernel will support.  The maximum supported value is 512 and the
 749           minimum value which makes sense is 2.
 750
 751           This is purely to save memory - each supported CPU adds
 752           approximately eight kilobytes to the kernel image.
 753
 754 config SCHED_SMT
 755         bool "SMT (Hyperthreading) scheduler support"
 756         depends on X86_HT
 757         ---help---
 758           SMT scheduler support improves the CPU scheduler's decision making
 759           when dealing with Intel Pentium 4 chips with HyperThreading at a
 760           cost of slightly increased overhead in some places. If unsure say
 761           N here.
 762
 763 config SCHED_MC
 764         def_bool y
 765         prompt "Multi-core scheduler support"
 766         depends on X86_HT
 767         ---help---
 768           Multi-core scheduler support improves the CPU scheduler's decision
 769           making when dealing with multi-core CPU chips at a cost of slightly
 770           increased overhead in some places. If unsure say N here.
 771
 772 source "kernel/Kconfig.preempt"
 773
 774 config X86_UP_APIC
 775         bool "Local APIC support on uniprocessors"
 776         depends on X86_32 && !SMP && !X86_32_NON_STANDARD
 777         ---help---
 778           A local APIC (Advanced Programmable Interrupt Controller) is an
 779           integrated interrupt controller in the CPU. If you have a single-CPU
 780           system which has a processor with a local APIC, you can say Y here to
 781           enable and use it. If you say Y here even though your machine doesn't
 782           have a local APIC, then the kernel will still run with no slowdown at
 783           all. The local APIC supports CPU-generated self-interrupts (timer,
 784           performance counters), and the NMI watchdog which detects hard
 785           lockups.
 786
 787 config X86_UP_IOAPIC
 788         bool "IO-APIC support on uniprocessors"
 789         depends on X86_UP_APIC
 790         ---help---
 791           An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
 792           SMP-capable replacement for PC-style interrupt controllers. Most
 793           SMP systems and many recent uniprocessor systems have one.
 794
 795           If you have a single-CPU system with an IO-APIC, you can say Y here
 796           to use it. If you say Y here even though your machine doesn't have
 797           an IO-APIC, then the kernel will still run with no slowdown at all.
 798
 799 config X86_LOCAL_APIC
 800         def_bool y
 801         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 802
 803 config X86_IO_APIC
 804         def_bool y
 805         depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
 806
 807 config X86_VISWS_APIC
 808         def_bool y
 809         depends on X86_32 && X86_VISWS
 810
 811 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
 812         bool "Reroute for broken boot IRQs"
 813         default n
 814         depends on X86_IO_APIC
 815         ---help---
 816           This option enables a workaround that fixes a source of
 817           spurious interrupts. This is recommended when threaded
 818           interrupt handling is used on systems where the generation of
 819           superfluous "boot interrupts" cannot be disabled.
 820
 821           Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
 822           entry in the chipset's IO-APIC is masked (as, e.g. the RT
 823           kernel does during interrupt handling). On chipsets where this
 824           boot IRQ generation cannot be disabled, this workaround keeps
 825           the original IRQ line masked so that only the equivalent "boot
 826           IRQ" is delivered to the CPUs. The workaround also tells the
 827           kernel to set up the IRQ handler on the boot IRQ line. In this
 828           way only one interrupt is delivered to the kernel. Otherwise
 829           the spurious second interrupt may cause the kernel to bring
 830           down (vital) interrupt lines.
 831
 832           Only affects "broken" chipsets. Interrupt sharing may be
 833           increased on these systems.
 834
 835 config X86_MCE
 836         bool "Machine Check / overheating reporting"
 837         ---help---
 838           Machine Check support allows the processor to notify the
 839           kernel if it detects a problem (e.g. overheating, data corruption).
 840           The action the kernel takes depends on the severity of the problem,
 841           ranging from warning messages to halting the machine.
 842
 843 config X86_MCE_INTEL
 844         def_bool y
 845         prompt "Intel MCE features"
 846         depends on X86_MCE && X86_LOCAL_APIC
 847         ---help---
 848            Additional support for intel specific MCE features such as
 849            the thermal monitor.
 850
 851 config X86_MCE_AMD
 852         def_bool y
 853         prompt "AMD MCE features"
 854         depends on X86_MCE && X86_LOCAL_APIC
 855         ---help---
 856            Additional support for AMD specific MCE features such as
 857            the DRAM Error Threshold.
 858
 859 config X86_ANCIENT_MCE
 860         def_bool n
 861         depends on X86_32 && X86_MCE
 862         prompt "Support for old Pentium 5 / WinChip machine checks"
 863         ---help---
 864           Include support for machine check handling on old Pentium 5 or WinChip
 865           systems. These typically need to be enabled explicitely on the command
 866           line.
 867
 868 config X86_MCE_THRESHOLD
 869         depends on X86_MCE_AMD || X86_MCE_INTEL
 870         bool
 871         default y
 872
 873 config X86_MCE_INJECT
 874         depends on X86_MCE
 875         tristate "Machine check injector support"
 876         ---help---
 877           Provide support for injecting machine checks for testing purposes.
 878           If you don't know what a machine check is and you don't do kernel
 879           QA it is safe to say n.
 880
 881 config X86_THERMAL_VECTOR
 882         def_bool y
 883         depends on X86_MCE_INTEL
 884
 885 config VM86
 886         bool "Enable VM86 support" if EMBEDDED
 887         default y
 888         depends on X86_32
 889         ---help---
 890           This option is required by programs like DOSEMU to run 16-bit legacy
 891           code on X86 processors. It also may be needed by software like
 892           XFree86 to initialize some video cards via BIOS. Disabling this
 893           option saves about 6k.
 894
 895 config TOSHIBA
 896         tristate "Toshiba Laptop support"
 897         depends on X86_32
 898         ---help---
 899           This adds a driver to safely access the System Management Mode of
 900           the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
 901           not work on models with a Phoenix BIOS. The System Management Mode
 902           is used to set the BIOS and power saving options on Toshiba portables.
 903
 904           For information on utilities to make use of this driver see the
 905           Toshiba Linux utilities web site at:
 906           <http://www.buzzard.org.uk/toshiba/>.
 907
 908           Say Y if you intend to run this kernel on a Toshiba portable.
 909           Say N otherwise.
 910
 911 config I8K
 912         tristate "Dell laptop support"
 913         ---help---
 914           This adds a driver to safely access the System Management Mode
 915           of the CPU on the Dell Inspiron 8000. The System Management Mode
 916           is used to read cpu temperature and cooling fan status and to
 917           control the fans on the I8K portables.
 918
 919           This driver has been tested only on the Inspiron 8000 but it may
 920           also work with other Dell laptops. You can force loading on other
 921           models by passing the parameter `force=1' to the module. Use at
 922           your own risk.
 923
 924           For information on utilities to make use of this driver see the
 925           I8K Linux utilities web site at:
 926           <http://people.debian.org/~dz/i8k/>
 927
 928           Say Y if you intend to run this kernel on a Dell Inspiron 8000.
 929           Say N otherwise.
 930
 931 config X86_REBOOTFIXUPS
 932         bool "Enable X86 board specific fixups for reboot"
 933         depends on X86_32
 934         ---help---
 935           This enables chipset and/or board specific fixups to be done
 936           in order to get reboot to work correctly. This is only needed on
 937           some combinations of hardware and BIOS. The symptom, for which
 938           this config is intended, is when reboot ends with a stalled/hung
 939           system.
 940
 941           Currently, the only fixup is for the Geode machines using
 942           CS5530A and CS5536 chipsets and the RDC R-321x SoC.
 943
 944           Say Y if you want to enable the fixup. Currently, it's safe to
 945           enable this option even if you don't need it.
 946           Say N otherwise.
 947
 948 config MICROCODE
 949         tristate "/dev/cpu/microcode - microcode support"
 950         select FW_LOADER
 951         ---help---
 952           If you say Y here, you will be able to update the microcode on
 953           certain Intel and AMD processors. The Intel support is for the
 954           IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
 955           Pentium 4, Xeon etc. The AMD support is for family 0x10 and
 956           0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
 957           You will obviously need the actual microcode binary data itself
 958           which is not shipped with the Linux kernel.
 959
 960           This option selects the general module only, you need to select
 961           at least one vendor specific module as well.
 962
 963           To compile this driver as a module, choose M here: the
 964           module will be called microcode.
 965
 966 config MICROCODE_INTEL
 967         bool "Intel microcode patch loading support"
 968         depends on MICROCODE
 969         default MICROCODE
 970         select FW_LOADER
 971         ---help---
 972           This options enables microcode patch loading support for Intel
 973           processors.
 974
 975           For latest news and information on obtaining all the required
 976           Intel ingredients for this driver, check:
 977           <http://www.urbanmyth.org/microcode/>.
 978
 979 config MICROCODE_AMD
 980         bool "AMD microcode patch loading support"
 981         depends on MICROCODE
 982         select FW_LOADER
 983         ---help---
 984           If you select this option, microcode patch loading support for AMD
 985           processors will be enabled.
 986
 987 config MICROCODE_OLD_INTERFACE
 988         def_bool y
 989         depends on MICROCODE
 990
 991 config X86_MSR
 992         tristate "/dev/cpu/*/msr - Model-specific register support"
 993         ---help---
 994           This device gives privileged processes access to the x86
 995           Model-Specific Registers (MSRs).  It is a character device with
 996           major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
 997           MSR accesses are directed to a specific CPU on multi-processor
 998           systems.
 999
1000 config X86_CPUID
1001         tristate "/dev/cpu/*/cpuid - CPU information support"
1002         ---help---
1003           This device gives processes access to the x86 CPUID instruction to
1004           be executed on a specific processor.  It is a character device
1005           with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1006           /dev/cpu/31/cpuid.
1007
1008 choice
1009         prompt "High Memory Support"
1010         default HIGHMEM4G if !X86_NUMAQ
1011         default HIGHMEM64G if X86_NUMAQ
1012         depends on X86_32
1013
1014 config NOHIGHMEM
1015         bool "off"
1016         depends on !X86_NUMAQ
1017         ---help---
1018           Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1019           However, the address space of 32-bit x86 processors is only 4
1020           Gigabytes large. That means that, if you have a large amount of
1021           physical memory, not all of it can be "permanently mapped" by the
1022           kernel. The physical memory that's not permanently mapped is called
1023           "high memory".
1024
1025           If you are compiling a kernel which will never run on a machine with
1026           more than 1 Gigabyte total physical RAM, answer "off" here (default
1027           choice and suitable for most users). This will result in a "3GB/1GB"
1028           split: 3GB are mapped so that each process sees a 3GB virtual memory
1029           space and the remaining part of the 4GB virtual memory space is used
1030           by the kernel to permanently map as much physical memory as
1031           possible.
1032
1033           If the machine has between 1 and 4 Gigabytes physical RAM, then
1034           answer "4GB" here.
1035
1036           If more than 4 Gigabytes is used then answer "64GB" here. This
1037           selection turns Intel PAE (Physical Address Extension) mode on.
1038           PAE implements 3-level paging on IA32 processors. PAE is fully
1039           supported by Linux, PAE mode is implemented on all recent Intel
1040           processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1041           then the kernel will not boot on CPUs that don't support PAE!
1042
1043           The actual amount of total physical memory will either be
1044           auto detected or can be forced by using a kernel command line option
1045           such as "mem=256M". (Try "man bootparam" or see the documentation of
1046           your boot loader (lilo or loadlin) about how to pass options to the
1047           kernel at boot time.)
1048
1049           If unsure, say "off".
1050
1051 config HIGHMEM4G
1052         bool "4GB"
1053         depends on !X86_NUMAQ
1054         ---help---
1055           Select this if you have a 32-bit processor and between 1 and 4
1056           gigabytes of physical RAM.
1057
1058 config HIGHMEM64G
1059         bool "64GB"
1060         depends on !M386 && !M486
1061         select X86_PAE
1062         ---help---
1063           Select this if you have a 32-bit processor and more than 4
1064           gigabytes of physical RAM.
1065
1066 endchoice
1067
1068 choice
1069         depends on EXPERIMENTAL
1070         prompt "Memory split" if EMBEDDED
1071         default VMSPLIT_3G
1072         depends on X86_32
1073         ---help---
1074           Select the desired split between kernel and user memory.
1075
1076           If the address range available to the kernel is less than the
1077           physical memory installed, the remaining memory will be available
1078           as "high memory". Accessing high memory is a little more costly
1079           than low memory, as it needs to be mapped into the kernel first.
1080           Note that increasing the kernel address space limits the range
1081           available to user programs, making the address space there
1082           tighter.  Selecting anything other than the default 3G/1G split
1083           will also likely make your kernel incompatible with binary-only
1084           kernel modules.
1085
1086           If you are not absolutely sure what you are doing, leave this
1087           option alone!
1088
1089         config VMSPLIT_3G
1090                 bool "3G/1G user/kernel split"
1091         config VMSPLIT_3G_OPT
1092                 depends on !X86_PAE
1093                 bool "3G/1G user/kernel split (for full 1G low memory)"
1094         config VMSPLIT_2G
1095                 bool "2G/2G user/kernel split"
1096         config VMSPLIT_2G_OPT
1097                 depends on !X86_PAE
1098                 bool "2G/2G user/kernel split (for full 2G low memory)"
1099         config VMSPLIT_1G
1100                 bool "1G/3G user/kernel split"
1101 endchoice
1102
1103 config PAGE_OFFSET
1104         hex
1105         default 0xB0000000 if VMSPLIT_3G_OPT
1106         default 0x80000000 if VMSPLIT_2G
1107         default 0x78000000 if VMSPLIT_2G_OPT
1108         default 0x40000000 if VMSPLIT_1G
1109         default 0xC0000000
1110         depends on X86_32
1111
1112 config HIGHMEM
1113         def_bool y
1114         depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1115
1116 config X86_PAE
1117         bool "PAE (Physical Address Extension) Support"
1118         depends on X86_32 && !HIGHMEM4G
1119         ---help---
1120           PAE is required for NX support, and furthermore enables
1121           larger swapspace support for non-overcommit purposes. It
1122           has the cost of more pagetable lookup overhead, and also
1123           consumes more pagetable space per process.
1124
1125 config ARCH_PHYS_ADDR_T_64BIT
1126         def_bool X86_64 || X86_PAE
1127
1128 config DIRECT_GBPAGES
1129         bool "Enable 1GB pages for kernel pagetables" if EMBEDDED
1130         default y
1131         depends on X86_64
1132         ---help---
1133           Allow the kernel linear mapping to use 1GB pages on CPUs that
1134           support it. This can improve the kernel's performance a tiny bit by
1135           reducing TLB pressure. If in doubt, say "Y".
1136
1137 # Common NUMA Features
1138 config NUMA
1139         bool "Numa Memory Allocation and Scheduler Support"
1140         depends on SMP
1141         depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1142         default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1143         ---help---
1144           Enable NUMA (Non Uniform Memory Access) support.
1145
1146           The kernel will try to allocate memory used by a CPU on the
1147           local memory controller of the CPU and add some more
1148           NUMA awareness to the kernel.
1149
1150           For 64-bit this is recommended if the system is Intel Core i7
1151           (or later), AMD Opteron, or EM64T NUMA.
1152
1153           For 32-bit this is only needed on (rare) 32-bit-only platforms
1154           that support NUMA topologies, such as NUMAQ / Summit, or if you
1155           boot a 32-bit kernel on a 64-bit NUMA platform.
1156
1157           Otherwise, you should say N.
1158
1159 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1160         depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1161
1162 config K8_NUMA
1163         def_bool y
1164         prompt "Old style AMD Opteron NUMA detection"
1165         depends on X86_64 && NUMA && PCI
1166         ---help---
1167           Enable K8 NUMA node topology detection.  You should say Y here if
1168           you have a multi processor AMD K8 system. This uses an old
1169           method to read the NUMA configuration directly from the builtin
1170           Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA
1171           instead, which also takes priority if both are compiled in.
1172
1173 config X86_64_ACPI_NUMA
1174         def_bool y
1175         prompt "ACPI NUMA detection"
1176         depends on X86_64 && NUMA && ACPI && PCI
1177         select ACPI_NUMA
1178         ---help---
1179           Enable ACPI SRAT based node topology detection.
1180
1181 # Some NUMA nodes have memory ranges that span
1182 # other nodes.  Even though a pfn is valid and
1183 # between a node's start and end pfns, it may not
1184 # reside on that node.  See memmap_init_zone()
1185 # for details.
1186 config NODES_SPAN_OTHER_NODES
1187         def_bool y
1188         depends on X86_64_ACPI_NUMA
1189
1190 config NUMA_EMU
1191         bool "NUMA emulation"
1192         depends on X86_64 && NUMA
1193         ---help---
1194           Enable NUMA emulation. A flat machine will be split
1195           into virtual nodes when booted with "numa=fake=N", where N is the
1196           number of nodes. This is only useful for debugging.
1197
1198 config NODES_SHIFT
1199         int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1200         range 1 9
1201         default "9" if MAXSMP
1202         default "6" if X86_64
1203         default "4" if X86_NUMAQ
1204         default "3"
1205         depends on NEED_MULTIPLE_NODES
1206         ---help---
1207           Specify the maximum number of NUMA Nodes available on the target
1208           system.  Increases memory reserved to accommodate various tables.
1209
1210 config HAVE_ARCH_BOOTMEM
1211         def_bool y
1212         depends on X86_32 && NUMA
1213
1214 config ARCH_HAVE_MEMORY_PRESENT
1215         def_bool y
1216         depends on X86_32 && DISCONTIGMEM
1217
1218 config NEED_NODE_MEMMAP_SIZE
1219         def_bool y
1220         depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1221
1222 config HAVE_ARCH_ALLOC_REMAP
1223         def_bool y
1224         depends on X86_32 && NUMA
1225
1226 config ARCH_FLATMEM_ENABLE
1227         def_bool y
1228         depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1229
1230 config ARCH_DISCONTIGMEM_ENABLE
1231         def_bool y
1232         depends on NUMA && X86_32
1233
1234 config ARCH_DISCONTIGMEM_DEFAULT
1235         def_bool y
1236         depends on NUMA && X86_32
1237
1238 config ARCH_PROC_KCORE_TEXT
1239         def_bool y
1240         depends on X86_64 && PROC_KCORE
1241
1242 config ARCH_SPARSEMEM_DEFAULT
1243         def_bool y
1244         depends on X86_64
1245
1246 config ARCH_SPARSEMEM_ENABLE
1247         def_bool y
1248         depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1249         select SPARSEMEM_STATIC if X86_32
1250         select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1251
1252 config ARCH_SELECT_MEMORY_MODEL
1253         def_bool y
1254         depends on ARCH_SPARSEMEM_ENABLE
1255
1256 config ARCH_MEMORY_PROBE
1257         def_bool X86_64
1258         depends on MEMORY_HOTPLUG
1259
1260 config ILLEGAL_POINTER_VALUE
1261        hex
1262        default 0 if X86_32
1263        default 0xdead000000000000 if X86_64
1264
1265 source "mm/Kconfig"
1266
1267 config HIGHPTE
1268         bool "Allocate 3rd-level pagetables from highmem"
1269         depends on X86_32 && (HIGHMEM4G || HIGHMEM64G)
1270         ---help---
1271           The VM uses one page table entry for each page of physical memory.
1272           For systems with a lot of RAM, this can be wasteful of precious
1273           low memory.  Setting this option will put user-space page table
1274           entries in high memory.
1275
1276 config X86_CHECK_BIOS_CORRUPTION
1277         bool "Check for low memory corruption"
1278         ---help---
1279           Periodically check for memory corruption in low memory, which
1280           is suspected to be caused by BIOS.  Even when enabled in the
1281           configuration, it is disabled at runtime.  Enable it by
1282           setting "memory_corruption_check=1" on the kernel command
1283           line.  By default it scans the low 64k of memory every 60
1284           seconds; see the memory_corruption_check_size and
1285           memory_corruption_check_period parameters in
1286           Documentation/kernel-parameters.txt to adjust this.
1287
1288           When enabled with the default parameters, this option has
1289           almost no overhead, as it reserves a relatively small amount
1290           of memory and scans it infrequently.  It both detects corruption
1291           and prevents it from affecting the running system.
1292
1293           It is, however, intended as a diagnostic tool; if repeatable
1294           BIOS-originated corruption always affects the same memory,
1295           you can use memmap= to prevent the kernel from using that
1296           memory.
1297
1298 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1299         bool "Set the default setting of memory_corruption_check"
1300         depends on X86_CHECK_BIOS_CORRUPTION
1301         default y
1302         ---help---
1303           Set whether the default state of memory_corruption_check is
1304           on or off.
1305
1306 config X86_RESERVE_LOW_64K
1307         bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen"
1308         default y
1309         ---help---
1310           Reserve the first 64K of physical RAM on BIOSes that are known
1311           to potentially corrupt that memory range. A numbers of BIOSes are
1312           known to utilize this area during suspend/resume, so it must not
1313           be used by the kernel.
1314
1315           Set this to N if you are absolutely sure that you trust the BIOS
1316           to get all its memory reservations and usages right.
1317
1318           If you have doubts about the BIOS (e.g. suspend/resume does not
1319           work or there's kernel crashes after certain hardware hotplug
1320           events) and it's not AMI or Phoenix, then you might want to enable
1321           X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical
1322           corruption patterns.
1323
1324           Say Y if unsure.
1325
1326 config MATH_EMULATION
1327         bool
1328         prompt "Math emulation" if X86_32
1329         ---help---
1330           Linux can emulate a math coprocessor (used for floating point
1331           operations) if you don't have one. 486DX and Pentium processors have
1332           a math coprocessor built in, 486SX and 386 do not, unless you added
1333           a 487DX or 387, respectively. (The messages during boot time can
1334           give you some hints here ["man dmesg"].) Everyone needs either a
1335           coprocessor or this emulation.
1336
1337           If you don't have a math coprocessor, you need to say Y here; if you
1338           say Y here even though you have a coprocessor, the coprocessor will
1339           be used nevertheless. (This behavior can be changed with the kernel
1340           command line option "no387", which comes handy if your coprocessor
1341           is broken. Try "man bootparam" or see the documentation of your boot
1342           loader (lilo or loadlin) about how to pass options to the kernel at
1343           boot time.) This means that it is a good idea to say Y here if you
1344           intend to use this kernel on different machines.
1345
1346           More information about the internals of the Linux math coprocessor
1347           emulation can be found in <file:arch/x86/math-emu/README>.
1348
1349           If you are not sure, say Y; apart from resulting in a 66 KB bigger
1350           kernel, it won't hurt.
1351
1352 config MTRR
1353         bool
1354         default y
1355         prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
1356         ---help---
1357           On Intel P6 family processors (Pentium Pro, Pentium II and later)
1358           the Memory Type Range Registers (MTRRs) may be used to control
1359           processor access to memory ranges. This is most useful if you have
1360           a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1361           allows bus write transfers to be combined into a larger transfer
1362           before bursting over the PCI/AGP bus. This can increase performance
1363           of image write operations 2.5 times or more. Saying Y here creates a
1364           /proc/mtrr file which may be used to manipulate your processor's
1365           MTRRs. Typically the X server should use this.
1366
1367           This code has a reasonably generic interface so that similar
1368           control registers on other processors can be easily supported
1369           as well:
1370
1371           The Cyrix 6x86, 6x86MX and M II processors have Address Range
1372           Registers (ARRs) which provide a similar functionality to MTRRs. For
1373           these, the ARRs are used to emulate the MTRRs.
1374           The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1375           MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1376           write-combining. All of these processors are supported by this code
1377           and it makes sense to say Y here if you have one of them.
1378
1379           Saying Y here also fixes a problem with buggy SMP BIOSes which only
1380           set the MTRRs for the boot CPU and not for the secondary CPUs. This
1381           can lead to all sorts of problems, so it's good to say Y here.
1382
1383           You can safely say Y even if your machine doesn't have MTRRs, you'll
1384           just add about 9 KB to your kernel.
1385
1386           See <file:Documentation/x86/mtrr.txt> for more information.
1387
1388 config MTRR_SANITIZER
1389         def_bool y
1390         prompt "MTRR cleanup support"
1391         depends on MTRR
1392         ---help---
1393           Convert MTRR layout from continuous to discrete, so X drivers can
1394           add writeback entries.
1395
1396           Can be disabled with disable_mtrr_cleanup on the kernel command line.
1397           The largest mtrr entry size for a continuous block can be set with
1398           mtrr_chunk_size.
1399
1400           If unsure, say Y.
1401
1402 config MTRR_SANITIZER_ENABLE_DEFAULT
1403         int "MTRR cleanup enable value (0-1)"
1404         range 0 1
1405         default "0"
1406         depends on MTRR_SANITIZER
1407         ---help---
1408           Enable mtrr cleanup default value
1409
1410 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1411         int "MTRR cleanup spare reg num (0-7)"
1412         range 0 7
1413         default "1"
1414         depends on MTRR_SANITIZER
1415         ---help---
1416           mtrr cleanup spare entries default, it can be changed via
1417           mtrr_spare_reg_nr=N on the kernel command line.
1418
1419 config X86_PAT
1420         bool
1421         default y
1422         prompt "x86 PAT support" if EMBEDDED
1423         depends on MTRR
1424         ---help---
1425           Use PAT attributes to setup page level cache control.
1426
1427           PATs are the modern equivalents of MTRRs and are much more
1428           flexible than MTRRs.
1429
1430           Say N here if you see bootup problems (boot crash, boot hang,
1431           spontaneous reboots) or a non-working video driver.
1432
1433           If unsure, say Y.
1434
1435 config ARCH_USES_PG_UNCACHED
1436         def_bool y
1437         depends on X86_PAT
1438
1439 config EFI
1440         bool "EFI runtime service support"
1441         depends on ACPI
1442         ---help---
1443           This enables the kernel to use EFI runtime services that are
1444           available (such as the EFI variable services).
1445
1446           This option is only useful on systems that have EFI firmware.
1447           In addition, you should use the latest ELILO loader available
1448           at <http://elilo.sourceforge.net> in order to take advantage
1449           of EFI runtime services. However, even with this option, the
1450           resultant kernel should continue to boot on existing non-EFI
1451           platforms.
1452
1453 config SECCOMP
1454         def_bool y
1455         prompt "Enable seccomp to safely compute untrusted bytecode"
1456         ---help---
1457           This kernel feature is useful for number crunching applications
1458           that may need to compute untrusted bytecode during their
1459           execution. By using pipes or other transports made available to
1460           the process as file descriptors supporting the read/write
1461           syscalls, it's possible to isolate those applications in
1462           their own address space using seccomp. Once seccomp is
1463           enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1464           and the task is only allowed to execute a few safe syscalls
1465           defined by each seccomp mode.
1466
1467           If unsure, say Y. Only embedded should say N here.
1468
1469 config CC_STACKPROTECTOR
1470         bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1471         ---help---
1472           This option turns on the -fstack-protector GCC feature. This
1473           feature puts, at the beginning of functions, a canary value on
1474           the stack just before the return address, and validates
1475           the value just before actually returning.  Stack based buffer
1476           overflows (that need to overwrite this return address) now also
1477           overwrite the canary, which gets detected and the attack is then
1478           neutralized via a kernel panic.
1479
1480           This feature requires gcc version 4.2 or above, or a distribution
1481           gcc with the feature backported. Older versions are automatically
1482           detected and for those versions, this configuration option is
1483           ignored. (and a warning is printed during bootup)
1484
1485 source kernel/Kconfig.hz
1486
1487 config KEXEC
1488         bool "kexec system call"
1489         ---help---
1490           kexec is a system call that implements the ability to shutdown your
1491           current kernel, and to start another kernel.  It is like a reboot
1492           but it is independent of the system firmware.   And like a reboot
1493           you can start any kernel with it, not just Linux.
1494
1495           The name comes from the similarity to the exec system call.
1496
1497           It is an ongoing process to be certain the hardware in a machine
1498           is properly shutdown, so do not be surprised if this code does not
1499           initially work for you.  It may help to enable device hotplugging
1500           support.  As of this writing the exact hardware interface is
1501           strongly in flux, so no good recommendation can be made.
1502
1503 config CRASH_DUMP
1504         bool "kernel crash dumps"
1505         depends on X86_64 || (X86_32 && HIGHMEM)
1506         ---help---
1507           Generate crash dump after being started by kexec.
1508           This should be normally only set in special crash dump kernels
1509           which are loaded in the main kernel with kexec-tools into
1510           a specially reserved region and then later executed after
1511           a crash by kdump/kexec. The crash dump kernel must be compiled
1512           to a memory address not used by the main kernel or BIOS using
1513           PHYSICAL_START, or it must be built as a relocatable image
1514           (CONFIG_RELOCATABLE=y).
1515           For more details see Documentation/kdump/kdump.txt
1516
1517 config KEXEC_JUMP
1518         bool "kexec jump (EXPERIMENTAL)"
1519         depends on EXPERIMENTAL
1520         depends on KEXEC && HIBERNATION
1521         ---help---
1522           Jump between original kernel and kexeced kernel and invoke
1523           code in physical address mode via KEXEC
1524
1525 config PHYSICAL_START
1526         hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP)
1527         default "0x1000000"
1528         ---help---
1529           This gives the physical address where the kernel is loaded.
1530
1531           If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1532           bzImage will decompress itself to above physical address and
1533           run from there. Otherwise, bzImage will run from the address where
1534           it has been loaded by the boot loader and will ignore above physical
1535           address.
1536
1537           In normal kdump cases one does not have to set/change this option
1538           as now bzImage can be compiled as a completely relocatable image
1539           (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1540           address. This option is mainly useful for the folks who don't want
1541           to use a bzImage for capturing the crash dump and want to use a
1542           vmlinux instead. vmlinux is not relocatable hence a kernel needs
1543           to be specifically compiled to run from a specific memory area
1544           (normally a reserved region) and this option comes handy.
1545
1546           So if you are using bzImage for capturing the crash dump,
1547           leave the value here unchanged to 0x1000000 and set
1548           CONFIG_RELOCATABLE=y.  Otherwise if you plan to use vmlinux
1549           for capturing the crash dump change this value to start of
1550           the reserved region.  In other words, it can be set based on
1551           the "X" value as specified in the "crashkernel=YM@XM"
1552           command line boot parameter passed to the panic-ed
1553           kernel. Please take a look at Documentation/kdump/kdump.txt
1554           for more details about crash dumps.
1555
1556           Usage of bzImage for capturing the crash dump is recommended as
1557           one does not have to build two kernels. Same kernel can be used
1558           as production kernel and capture kernel. Above option should have
1559           gone away after relocatable bzImage support is introduced. But it
1560           is present because there are users out there who continue to use
1561           vmlinux for dump capture. This option should go away down the
1562           line.
1563
1564           Don't change this unless you know what you are doing.
1565
1566 config RELOCATABLE
1567         bool "Build a relocatable kernel"
1568         default y
1569         ---help---
1570           This builds a kernel image that retains relocation information
1571           so it can be loaded someplace besides the default 1MB.
1572           The relocations tend to make the kernel binary about 10% larger,
1573           but are discarded at runtime.
1574
1575           One use is for the kexec on panic case where the recovery kernel
1576           must live at a different physical address than the primary
1577           kernel.
1578
1579           Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1580           it has been loaded at and the compile time physical address
1581           (CONFIG_PHYSICAL_START) is ignored.
1582
1583 # Relocation on x86-32 needs some additional build support
1584 config X86_NEED_RELOCS
1585         def_bool y
1586         depends on X86_32 && RELOCATABLE
1587
1588 config PHYSICAL_ALIGN
1589         hex
1590         prompt "Alignment value to which kernel should be aligned" if X86_32
1591         default "0x1000000"
1592         range 0x2000 0x1000000
1593         ---help---
1594           This value puts the alignment restrictions on physical address
1595           where kernel is loaded and run from. Kernel is compiled for an
1596           address which meets above alignment restriction.
1597
1598           If bootloader loads the kernel at a non-aligned address and
1599           CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1600           address aligned to above value and run from there.
1601
1602           If bootloader loads the kernel at a non-aligned address and
1603           CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1604           load address and decompress itself to the address it has been
1605           compiled for and run from there. The address for which kernel is
1606           compiled already meets above alignment restrictions. Hence the
1607           end result is that kernel runs from a physical address meeting
1608           above alignment restrictions.
1609
1610           Don't change this unless you know what you are doing.
1611
1612 config HOTPLUG_CPU
1613         bool "Support for hot-pluggable CPUs"
1614         depends on SMP && HOTPLUG
1615         ---help---
1616           Say Y here to allow turning CPUs off and on. CPUs can be
1617           controlled through /sys/devices/system/cpu.
1618           ( Note: power management support will enable this option
1619             automatically on SMP systems. )
1620           Say N if you want to disable CPU hotplug.
1621
1622 config COMPAT_VDSO
1623         def_bool y
1624         prompt "Compat VDSO support"
1625         depends on X86_32 || IA32_EMULATION
1626         ---help---
1627           Map the 32-bit VDSO to the predictable old-style address too.
1628
1629           Say N here if you are running a sufficiently recent glibc
1630           version (2.3.3 or later), to remove the high-mapped
1631           VDSO mapping and to exclusively use the randomized VDSO.
1632
1633           If unsure, say Y.
1634
1635 config CMDLINE_BOOL
1636         bool "Built-in kernel command line"
1637         default n
1638         ---help---
1639           Allow for specifying boot arguments to the kernel at
1640           build time.  On some systems (e.g. embedded ones), it is
1641           necessary or convenient to provide some or all of the
1642           kernel boot arguments with the kernel itself (that is,
1643           to not rely on the boot loader to provide them.)
1644
1645           To compile command line arguments into the kernel,
1646           set this option to 'Y', then fill in the
1647           the boot arguments in CONFIG_CMDLINE.
1648
1649           Systems with fully functional boot loaders (i.e. non-embedded)
1650           should leave this option set to 'N'.
1651
1652 config CMDLINE
1653         string "Built-in kernel command string"
1654         depends on CMDLINE_BOOL
1655         default ""
1656         ---help---
1657           Enter arguments here that should be compiled into the kernel
1658           image and used at boot time.  If the boot loader provides a
1659           command line at boot time, it is appended to this string to
1660           form the full kernel command line, when the system boots.
1661
1662           However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1663           change this behavior.
1664
1665           In most cases, the command line (whether built-in or provided
1666           by the boot loader) should specify the device for the root
1667           file system.
1668
1669 config CMDLINE_OVERRIDE
1670         bool "Built-in command line overrides boot loader arguments"
1671         default n
1672         depends on CMDLINE_BOOL
1673         ---help---
1674           Set this option to 'Y' to have the kernel ignore the boot loader
1675           command line, and use ONLY the built-in command line.
1676
1677           This is used to work around broken boot loaders.  This should
1678           be set to 'N' under normal conditions.
1679
1680 endmenu
1681
1682 config ARCH_ENABLE_MEMORY_HOTPLUG
1683         def_bool y
1684         depends on X86_64 || (X86_32 && HIGHMEM)
1685
1686 config ARCH_ENABLE_MEMORY_HOTREMOVE
1687         def_bool y
1688         depends on MEMORY_HOTPLUG
1689
1690 config HAVE_ARCH_EARLY_PFN_TO_NID
1691         def_bool X86_64
1692         depends on NUMA
1693
1694 menu "Power management and ACPI options"
1695
1696 config ARCH_HIBERNATION_HEADER
1697         def_bool y
1698         depends on X86_64 && HIBERNATION
1699
1700 source "kernel/power/Kconfig"
1701
1702 source "drivers/acpi/Kconfig"
1703
1704 source "drivers/sfi/Kconfig"
1705
1706 config X86_APM_BOOT
1707         bool
1708         default y
1709         depends on APM || APM_MODULE
1710
1711 menuconfig APM
1712         tristate "APM (Advanced Power Management) BIOS support"
1713         depends on X86_32 && PM_SLEEP
1714         ---help---
1715           APM is a BIOS specification for saving power using several different
1716           techniques. This is mostly useful for battery powered laptops with
1717           APM compliant BIOSes. If you say Y here, the system time will be
1718           reset after a RESUME operation, the /proc/apm device will provide
1719           battery status information, and user-space programs will receive
1720           notification of APM "events" (e.g. battery status change).
1721
1722           If you select "Y" here, you can disable actual use of the APM
1723           BIOS by passing the "apm=off" option to the kernel at boot time.
1724
1725           Note that the APM support is almost completely disabled for
1726           machines with more than one CPU.
1727
1728           In order to use APM, you will need supporting software. For location
1729           and more information, read <file:Documentation/power/pm.txt> and the
1730           Battery Powered Linux mini-HOWTO, available from
1731           <http://www.tldp.org/docs.html#howto>.
1732
1733           This driver does not spin down disk drives (see the hdparm(8)
1734           manpage ("man 8 hdparm") for that), and it doesn't turn off
1735           VESA-compliant "green" monitors.
1736
1737           This driver does not support the TI 4000M TravelMate and the ACER
1738           486/DX4/75 because they don't have compliant BIOSes. Many "green"
1739           desktop machines also don't have compliant BIOSes, and this driver
1740           may cause those machines to panic during the boot phase.
1741
1742           Generally, if you don't have a battery in your machine, there isn't
1743           much point in using this driver and you should say N. If you get
1744           random kernel OOPSes or reboots that don't seem to be related to
1745           anything, try disabling/enabling this option (or disabling/enabling
1746           APM in your BIOS).
1747
1748           Some other things you should try when experiencing seemingly random,
1749           "weird" problems:
1750
1751           1) make sure that you have enough swap space and that it is
1752           enabled.
1753           2) pass the "no-hlt" option to the kernel
1754           3) switch on floating point emulation in the kernel and pass
1755           the "no387" option to the kernel
1756           4) pass the "floppy=nodma" option to the kernel
1757           5) pass the "mem=4M" option to the kernel (thereby disabling
1758           all but the first 4 MB of RAM)
1759           6) make sure that the CPU is not over clocked.
1760           7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1761           8) disable the cache from your BIOS settings
1762           9) install a fan for the video card or exchange video RAM
1763           10) install a better fan for the CPU
1764           11) exchange RAM chips
1765           12) exchange the motherboard.
1766
1767           To compile this driver as a module, choose M here: the
1768           module will be called apm.
1769
1770 if APM
1771
1772 config APM_IGNORE_USER_SUSPEND
1773         bool "Ignore USER SUSPEND"
1774         ---help---
1775           This option will ignore USER SUSPEND requests. On machines with a
1776           compliant APM BIOS, you want to say N. However, on the NEC Versa M
1777           series notebooks, it is necessary to say Y because of a BIOS bug.
1778
1779 config APM_DO_ENABLE
1780         bool "Enable PM at boot time"
1781         ---help---
1782           Enable APM features at boot time. From page 36 of the APM BIOS
1783           specification: "When disabled, the APM BIOS does not automatically
1784           power manage devices, enter the Standby State, enter the Suspend
1785           State, or take power saving steps in response to CPU Idle calls."
1786           This driver will make CPU Idle calls when Linux is idle (unless this
1787           feature is turned off -- see "Do CPU IDLE calls", below). This
1788           should always save battery power, but more complicated APM features
1789           will be dependent on your BIOS implementation. You may need to turn
1790           this option off if your computer hangs at boot time when using APM
1791           support, or if it beeps continuously instead of suspending. Turn
1792           this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1793           T400CDT. This is off by default since most machines do fine without
1794           this feature.
1795
1796 config APM_CPU_IDLE
1797         bool "Make CPU Idle calls when idle"
1798         ---help---
1799           Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1800           On some machines, this can activate improved power savings, such as
1801           a slowed CPU clock rate, when the machine is idle. These idle calls
1802           are made after the idle loop has run for some length of time (e.g.,
1803           333 mS). On some machines, this will cause a hang at boot time or
1804           whenever the CPU becomes idle. (On machines with more than one CPU,
1805           this option does nothing.)
1806
1807 config APM_DISPLAY_BLANK
1808         bool "Enable console blanking using APM"
1809         ---help---
1810           Enable console blanking using the APM. Some laptops can use this to
1811           turn off the LCD backlight when the screen blanker of the Linux
1812           virtual console blanks the screen. Note that this is only used by
1813           the virtual console screen blanker, and won't turn off the backlight
1814           when using the X Window system. This also doesn't have anything to
1815           do with your VESA-compliant power-saving monitor. Further, this
1816           option doesn't work for all laptops -- it might not turn off your
1817           backlight at all, or it might print a lot of errors to the console,
1818           especially if you are using gpm.
1819
1820 config APM_ALLOW_INTS
1821         bool "Allow interrupts during APM BIOS calls"
1822         ---help---
1823           Normally we disable external interrupts while we are making calls to
1824           the APM BIOS as a measure to lessen the effects of a badly behaving
1825           BIOS implementation.  The BIOS should reenable interrupts if it
1826           needs to.  Unfortunately, some BIOSes do not -- especially those in
1827           many of the newer IBM Thinkpads.  If you experience hangs when you
1828           suspend, try setting this to Y.  Otherwise, say N.
1829
1830 endif # APM
1831
1832 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1833
1834 source "drivers/cpuidle/Kconfig"
1835
1836 source "drivers/idle/Kconfig"
1837
1838 endmenu
1839
1840
1841 menu "Bus options (PCI etc.)"
1842
1843 config PCI
1844         bool "PCI support"
1845         default y
1846         select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1847         ---help---
1848           Find out whether you have a PCI motherboard. PCI is the name of a
1849           bus system, i.e. the way the CPU talks to the other stuff inside
1850           your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1851           VESA. If you have PCI, say Y, otherwise N.
1852
1853 choice
1854         prompt "PCI access mode"
1855         depends on X86_32 && PCI
1856         default PCI_GOANY
1857         ---help---
1858           On PCI systems, the BIOS can be used to detect the PCI devices and
1859           determine their configuration. However, some old PCI motherboards
1860           have BIOS bugs and may crash if this is done. Also, some embedded
1861           PCI-based systems don't have any BIOS at all. Linux can also try to
1862           detect the PCI hardware directly without using the BIOS.
1863
1864           With this option, you can specify how Linux should detect the
1865           PCI devices. If you choose "BIOS", the BIOS will be used,
1866           if you choose "Direct", the BIOS won't be used, and if you
1867           choose "MMConfig", then PCI Express MMCONFIG will be used.
1868           If you choose "Any", the kernel will try MMCONFIG, then the
1869           direct access method and falls back to the BIOS if that doesn't
1870           work. If unsure, go with the default, which is "Any".
1871
1872 config PCI_GOBIOS
1873         bool "BIOS"
1874
1875 config PCI_GOMMCONFIG
1876         bool "MMConfig"
1877
1878 config PCI_GODIRECT
1879         bool "Direct"
1880
1881 config PCI_GOOLPC
1882         bool "OLPC"
1883         depends on OLPC
1884
1885 config PCI_GOANY
1886         bool "Any"
1887
1888 endchoice
1889
1890 config PCI_BIOS
1891         def_bool y
1892         depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1893
1894 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1895 config PCI_DIRECT
1896         def_bool y
1897         depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1898
1899 config PCI_MMCONFIG
1900         def_bool y
1901         depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1902
1903 config PCI_OLPC
1904         def_bool y
1905         depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1906
1907 config PCI_DOMAINS
1908         def_bool y
1909         depends on PCI
1910
1911 config PCI_MMCONFIG
1912         bool "Support mmconfig PCI config space access"
1913         depends on X86_64 && PCI && ACPI
1914
1915 config DMAR
1916         bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1917         depends on PCI_MSI && ACPI && EXPERIMENTAL
1918         help
1919           DMA remapping (DMAR) devices support enables independent address
1920           translations for Direct Memory Access (DMA) from devices.
1921           These DMA remapping devices are reported via ACPI tables
1922           and include PCI device scope covered by these DMA
1923           remapping devices.
1924
1925 config DMAR_DEFAULT_ON
1926         def_bool y
1927         prompt "Enable DMA Remapping Devices by default"
1928         depends on DMAR
1929         help
1930           Selecting this option will enable a DMAR device at boot time if
1931           one is found. If this option is not selected, DMAR support can
1932           be enabled by passing intel_iommu=on to the kernel. It is
1933           recommended you say N here while the DMAR code remains
1934           experimental.
1935
1936 config DMAR_BROKEN_GFX_WA
1937         def_bool n
1938         prompt "Workaround broken graphics drivers (going away soon)"
1939         depends on DMAR && BROKEN
1940         ---help---
1941           Current Graphics drivers tend to use physical address
1942           for DMA and avoid using DMA APIs. Setting this config
1943           option permits the IOMMU driver to set a unity map for
1944           all the OS-visible memory. Hence the driver can continue
1945           to use physical addresses for DMA, at least until this
1946           option is removed in the 2.6.32 kernel.
1947
1948 config DMAR_FLOPPY_WA
1949         def_bool y
1950         depends on DMAR
1951         ---help---
1952           Floppy disk drivers are known to bypass DMA API calls
1953           thereby failing to work when IOMMU is enabled. This
1954           workaround will setup a 1:1 mapping for the first
1955           16MiB to make floppy (an ISA device) work.
1956
1957 config INTR_REMAP
1958         bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1959         depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1960         ---help---
1961           Supports Interrupt remapping for IO-APIC and MSI devices.
1962           To use x2apic mode in the CPU's which support x2APIC enhancements or
1963           to support platforms with CPU's having > 8 bit APIC ID, say Y.
1964
1965 source "drivers/pci/pcie/Kconfig"
1966
1967 source "drivers/pci/Kconfig"
1968
1969 # x86_64 have no ISA slots, but do have ISA-style DMA.
1970 config ISA_DMA_API
1971         def_bool y
1972
1973 if X86_32
1974
1975 config ISA
1976         bool "ISA support"
1977         ---help---
1978           Find out whether you have ISA slots on your motherboard.  ISA is the
1979           name of a bus system, i.e. the way the CPU talks to the other stuff
1980           inside your box.  Other bus systems are PCI, EISA, MicroChannel
1981           (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1982           newer boards don't support it.  If you have ISA, say Y, otherwise N.
1983
1984 config EISA
1985         bool "EISA support"
1986         depends on ISA
1987         ---help---
1988           The Extended Industry Standard Architecture (EISA) bus was
1989           developed as an open alternative to the IBM MicroChannel bus.
1990
1991           The EISA bus provided some of the features of the IBM MicroChannel
1992           bus while maintaining backward compatibility with cards made for
1993           the older ISA bus.  The EISA bus saw limited use between 1988 and
1994           1995 when it was made obsolete by the PCI bus.
1995
1996           Say Y here if you are building a kernel for an EISA-based machine.
1997
1998           Otherwise, say N.
1999
2000 source "drivers/eisa/Kconfig"
2001
2002 config MCA
2003         bool "MCA support"
2004         ---help---
2005           MicroChannel Architecture is found in some IBM PS/2 machines and
2006           laptops.  It is a bus system similar to PCI or ISA. See
2007           <file:Documentation/mca.txt> (and especially the web page given
2008           there) before attempting to build an MCA bus kernel.
2009
2010 source "drivers/mca/Kconfig"
2011
2012 config SCx200
2013         tristate "NatSemi SCx200 support"
2014         ---help---
2015           This provides basic support for National Semiconductor's
2016           (now AMD's) Geode processors.  The driver probes for the
2017           PCI-IDs of several on-chip devices, so its a good dependency
2018           for other scx200_* drivers.
2019
2020           If compiled as a module, the driver is named scx200.
2021
2022 config SCx200HR_TIMER
2023         tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2024         depends on SCx200 && GENERIC_TIME
2025         default y
2026         ---help---
2027           This driver provides a clocksource built upon the on-chip
2028           27MHz high-resolution timer.  Its also a workaround for
2029           NSC Geode SC-1100's buggy TSC, which loses time when the
2030           processor goes idle (as is done by the scheduler).  The
2031           other workaround is idle=poll boot option.
2032
2033 config OLPC
2034         bool "One Laptop Per Child support"
2035         select GPIOLIB
2036         default n
2037         ---help---
2038           Add support for detecting the unique features of the OLPC
2039           XO hardware.
2040
2041 endif # X86_32
2042
2043 config K8_NB
2044         def_bool y
2045         depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA)))
2046
2047 source "drivers/pcmcia/Kconfig"
2048
2049 source "drivers/pci/hotplug/Kconfig"
2050
2051 endmenu
2052
2053
2054 menu "Executable file formats / Emulations"
2055
2056 source "fs/Kconfig.binfmt"
2057
2058 config IA32_EMULATION
2059         bool "IA32 Emulation"
2060         depends on X86_64
2061         select COMPAT_BINFMT_ELF
2062         ---help---
2063           Include code to run 32-bit programs under a 64-bit kernel. You should
2064           likely turn this on, unless you're 100% sure that you don't have any
2065           32-bit programs left.
2066
2067 config IA32_AOUT
2068         tristate "IA32 a.out support"
2069         depends on IA32_EMULATION
2070         ---help---
2071           Support old a.out binaries in the 32bit emulation.
2072
2073 config COMPAT
2074         def_bool y
2075         depends on IA32_EMULATION
2076
2077 config COMPAT_FOR_U64_ALIGNMENT
2078         def_bool COMPAT
2079         depends on X86_64
2080
2081 config SYSVIPC_COMPAT
2082         def_bool y
2083         depends on COMPAT && SYSVIPC
2084
2085 endmenu
2086
2087
2088 config HAVE_ATOMIC_IOMAP
2089         def_bool y
2090         depends on X86_32
2091
2092 source "net/Kconfig"
2093
2094 source "drivers/Kconfig"
2095
2096 source "drivers/firmware/Kconfig"
2097
2098 source "fs/Kconfig"
2099
2100 source "arch/x86/Kconfig.debug"
2101
2102 source "security/Kconfig"
2103
2104 source "crypto/Kconfig"
2105
2106 source "arch/x86/kvm/Kconfig"
2107
2108 source "lib/Kconfig"