1# x86 configuration 2mainmenu "Linux Kernel Configuration for x86" 3 4# Select 32 or 64 bit 5config 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 12config X86_32 13 def_bool !64BIT 14 15config X86_64 16 def_bool 64BIT 17 18### Arch settings 19config 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_DMA_API_DEBUG 49 select HAVE_KERNEL_GZIP 50 select HAVE_KERNEL_BZIP2 51 select HAVE_KERNEL_LZMA 52 select HAVE_ARCH_KMEMCHECK 53 54config OUTPUT_FORMAT 55 string 56 default "elf32-i386" if X86_32 57 default "elf64-x86-64" if X86_64 58 59config ARCH_DEFCONFIG 60 string 61 default "arch/x86/configs/i386_defconfig" if X86_32 62 default "arch/x86/configs/x86_64_defconfig" if X86_64 63 64config GENERIC_TIME 65 def_bool y 66 67config GENERIC_CMOS_UPDATE 68 def_bool y 69 70config CLOCKSOURCE_WATCHDOG 71 def_bool y 72 73config GENERIC_CLOCKEVENTS 74 def_bool y 75 76config GENERIC_CLOCKEVENTS_BROADCAST 77 def_bool y 78 depends on X86_64 || (X86_32 && X86_LOCAL_APIC) 79 80config LOCKDEP_SUPPORT 81 def_bool y 82 83config STACKTRACE_SUPPORT 84 def_bool y 85 86config HAVE_LATENCYTOP_SUPPORT 87 def_bool y 88 89config FAST_CMPXCHG_LOCAL 90 bool 91 default y 92 93config MMU 94 def_bool y 95 96config ZONE_DMA 97 def_bool y 98 99config SBUS 100 bool 101 102config GENERIC_ISA_DMA 103 def_bool y 104 105config GENERIC_IOMAP 106 def_bool y 107 108config GENERIC_BUG 109 def_bool y 110 depends on BUG 111 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 112 113config GENERIC_BUG_RELATIVE_POINTERS 114 bool 115 116config GENERIC_HWEIGHT 117 def_bool y 118 119config GENERIC_GPIO 120 bool 121 122config ARCH_MAY_HAVE_PC_FDC 123 def_bool y 124 125config RWSEM_GENERIC_SPINLOCK 126 def_bool !X86_XADD 127 128config RWSEM_XCHGADD_ALGORITHM 129 def_bool X86_XADD 130 131config ARCH_HAS_CPU_IDLE_WAIT 132 def_bool y 133 134config GENERIC_CALIBRATE_DELAY 135 def_bool y 136 137config GENERIC_TIME_VSYSCALL 138 bool 139 default X86_64 140 141config ARCH_HAS_CPU_RELAX 142 def_bool y 143 144config ARCH_HAS_DEFAULT_IDLE 145 def_bool y 146 147config ARCH_HAS_CACHE_LINE_SIZE 148 def_bool y 149 150config HAVE_SETUP_PER_CPU_AREA 151 def_bool y 152 153config NEED_PER_CPU_EMBED_FIRST_CHUNK 154 def_bool y 155 156config NEED_PER_CPU_PAGE_FIRST_CHUNK 157 def_bool y 158 159config HAVE_CPUMASK_OF_CPU_MAP 160 def_bool X86_64_SMP 161 162config ARCH_HIBERNATION_POSSIBLE 163 def_bool y 164 165config ARCH_SUSPEND_POSSIBLE 166 def_bool y 167 168config ZONE_DMA32 169 bool 170 default X86_64 171 172config ARCH_POPULATES_NODE_MAP 173 def_bool y 174 175config AUDIT_ARCH 176 bool 177 default X86_64 178 179config ARCH_SUPPORTS_OPTIMIZED_INLINING 180 def_bool y 181 182config ARCH_SUPPORTS_DEBUG_PAGEALLOC 183 def_bool y 184 185config HAVE_INTEL_TXT 186 def_bool y 187 depends on EXPERIMENTAL && DMAR && ACPI 188 189# Use the generic interrupt handling code in kernel/irq/: 190config GENERIC_HARDIRQS 191 bool 192 default y 193 194config GENERIC_HARDIRQS_NO__DO_IRQ 195 def_bool y 196 197config GENERIC_IRQ_PROBE 198 bool 199 default y 200 201config GENERIC_PENDING_IRQ 202 bool 203 depends on GENERIC_HARDIRQS && SMP 204 default y 205 206config USE_GENERIC_SMP_HELPERS 207 def_bool y 208 depends on SMP 209 210config X86_32_SMP 211 def_bool y 212 depends on X86_32 && SMP 213 214config X86_64_SMP 215 def_bool y 216 depends on X86_64 && SMP 217 218config X86_HT 219 bool 220 depends on SMP 221 default y 222 223config X86_TRAMPOLINE 224 bool 225 depends on SMP || (64BIT && ACPI_SLEEP) 226 default y 227 228config X86_32_LAZY_GS 229 def_bool y 230 depends on X86_32 && !CC_STACKPROTECTOR 231 232config KTIME_SCALAR 233 def_bool X86_32 234source "init/Kconfig" 235source "kernel/Kconfig.freezer" 236 237menu "Processor type and features" 238 239source "kernel/time/Kconfig" 240 241config SMP 242 bool "Symmetric multi-processing support" 243 ---help--- 244 This enables support for systems with more than one CPU. If you have 245 a system with only one CPU, like most personal computers, say N. If 246 you have a system with more than one CPU, say Y. 247 248 If you say N here, the kernel will run on single and multiprocessor 249 machines, but will use only one CPU of a multiprocessor machine. If 250 you say Y here, the kernel will run on many, but not all, 251 singleprocessor machines. On a singleprocessor machine, the kernel 252 will run faster if you say N here. 253 254 Note that if you say Y here and choose architecture "586" or 255 "Pentium" under "Processor family", the kernel will not work on 486 256 architectures. Similarly, multiprocessor kernels for the "PPro" 257 architecture may not work on all Pentium based boards. 258 259 People using multiprocessor machines who say Y here should also say 260 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 261 Management" code will be disabled if you say Y here. 262 263 See also <file:Documentation/i386/IO-APIC.txt>, 264 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 265 <http://www.tldp.org/docs.html#howto>. 266 267 If you don't know what to do here, say N. 268 269config X86_X2APIC 270 bool "Support x2apic" 271 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP 272 ---help--- 273 This enables x2apic support on CPUs that have this feature. 274 275 This allows 32-bit apic IDs (so it can support very large systems), 276 and accesses the local apic via MSRs not via mmio. 277 278 If you don't know what to do here, say N. 279 280config SPARSE_IRQ 281 bool "Support sparse irq numbering" 282 depends on PCI_MSI || HT_IRQ 283 ---help--- 284 This enables support for sparse irqs. This is useful for distro 285 kernels that want to define a high CONFIG_NR_CPUS value but still 286 want to have low kernel memory footprint on smaller machines. 287 288 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread 289 out the irq_desc[] array in a more NUMA-friendly way. ) 290 291 If you don't know what to do here, say N. 292 293config NUMA_IRQ_DESC 294 def_bool y 295 depends on SPARSE_IRQ && NUMA 296 297config 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 305config 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 311if X86_32 312config 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. 332endif 333 334if X86_64 335config 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 ScaleMP vSMP 346 SGI Ultraviolet 347 348 If you have one of these systems, or if you want to build a 349 generic distribution kernel, say Y here - otherwise say N. 350endif 351# This is an alphabetically sorted list of 64 bit extended platforms 352# Please maintain the alphabetic order if and when there are additions 353 354config X86_VSMP 355 bool "ScaleMP vSMP" 356 select PARAVIRT 357 depends on X86_64 && PCI 358 depends on X86_EXTENDED_PLATFORM 359 ---help--- 360 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 361 supposed to run on these EM64T-based machines. Only choose this option 362 if you have one of these machines. 363 364config X86_UV 365 bool "SGI Ultraviolet" 366 depends on X86_64 367 depends on X86_EXTENDED_PLATFORM 368 depends on NUMA 369 depends on X86_X2APIC 370 ---help--- 371 This option is needed in order to support SGI Ultraviolet systems. 372 If you don't have one of these, you should say N here. 373 374# Following is an alphabetically sorted list of 32 bit extended platforms 375# Please maintain the alphabetic order if and when there are additions 376 377config X86_ELAN 378 bool "AMD Elan" 379 depends on X86_32 380 depends on X86_EXTENDED_PLATFORM 381 ---help--- 382 Select this for an AMD Elan processor. 383 384 Do not use this option for K6/Athlon/Opteron processors! 385 386 If unsure, choose "PC-compatible" instead. 387 388config X86_MRST 389 bool "Moorestown MID platform" 390 depends on X86_32 391 depends on X86_EXTENDED_PLATFORM 392 ---help--- 393 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin 394 Internet Device(MID) platform. Moorestown consists of two chips: 395 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH. 396 Unlike standard x86 PCs, Moorestown does not have many legacy devices 397 nor standard legacy replacement devices/features. e.g. Moorestown does 398 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports. 399 400config X86_RDC321X 401 bool "RDC R-321x SoC" 402 depends on X86_32 403 depends on X86_EXTENDED_PLATFORM 404 select M486 405 select X86_REBOOTFIXUPS 406 ---help--- 407 This option is needed for RDC R-321x system-on-chip, also known 408 as R-8610-(G). 409 If you don't have one of these chips, you should say N here. 410 411config X86_32_NON_STANDARD 412 bool "Support non-standard 32-bit SMP architectures" 413 depends on X86_32 && SMP 414 depends on X86_EXTENDED_PLATFORM 415 ---help--- 416 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default 417 subarchitectures. It is intended for a generic binary kernel. 418 if you select them all, kernel will probe it one by one. and will 419 fallback to default. 420 421# Alphabetically sorted list of Non standard 32 bit platforms 422 423config X86_NUMAQ 424 bool "NUMAQ (IBM/Sequent)" 425 depends on X86_32_NON_STANDARD 426 select NUMA 427 select X86_MPPARSE 428 ---help--- 429 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent) 430 NUMA multiquad box. This changes the way that processors are 431 bootstrapped, and uses Clustered Logical APIC addressing mode instead 432 of Flat Logical. You will need a new lynxer.elf file to flash your 433 firmware with - send email to <Martin.Bligh@us.ibm.com>. 434 435config X86_SUPPORTS_MEMORY_FAILURE 436 bool 437 # MCE code calls memory_failure(): 438 depends on X86_MCE 439 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 440 depends on !X86_NUMAQ 441 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 442 depends on X86_64 || !SPARSEMEM 443 select ARCH_SUPPORTS_MEMORY_FAILURE 444 default y 445 446config X86_VISWS 447 bool "SGI 320/540 (Visual Workstation)" 448 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT 449 depends on X86_32_NON_STANDARD 450 ---help--- 451 The SGI Visual Workstation series is an IA32-based workstation 452 based on SGI systems chips with some legacy PC hardware attached. 453 454 Say Y here to create a kernel to run on the SGI 320 or 540. 455 456 A kernel compiled for the Visual Workstation will run on general 457 PCs as well. See <file:Documentation/sgi-visws.txt> for details. 458 459config X86_SUMMIT 460 bool "Summit/EXA (IBM x440)" 461 depends on X86_32_NON_STANDARD 462 ---help--- 463 This option is needed for IBM systems that use the Summit/EXA chipset. 464 In particular, it is needed for the x440. 465 466config X86_ES7000 467 bool "Unisys ES7000 IA32 series" 468 depends on X86_32_NON_STANDARD && X86_BIGSMP 469 ---help--- 470 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 471 supposed to run on an IA32-based Unisys ES7000 system. 472 473config SCHED_OMIT_FRAME_POINTER 474 def_bool y 475 prompt "Single-depth WCHAN output" 476 depends on X86 477 ---help--- 478 Calculate simpler /proc/<PID>/wchan values. If this option 479 is disabled then wchan values will recurse back to the 480 caller function. This provides more accurate wchan values, 481 at the expense of slightly more scheduling overhead. 482 483 If in doubt, say "Y". 484 485menuconfig PARAVIRT_GUEST 486 bool "Paravirtualized guest support" 487 ---help--- 488 Say Y here to get to see options related to running Linux under 489 various hypervisors. This option alone does not add any kernel code. 490 491 If you say N, all options in this submenu will be skipped and disabled. 492 493if PARAVIRT_GUEST 494 495source "arch/x86/xen/Kconfig" 496 497config VMI 498 bool "VMI Guest support" 499 select PARAVIRT 500 depends on X86_32 501 ---help--- 502 VMI provides a paravirtualized interface to the VMware ESX server 503 (it could be used by other hypervisors in theory too, but is not 504 at the moment), by linking the kernel to a GPL-ed ROM module 505 provided by the hypervisor. 506 507config KVM_CLOCK 508 bool "KVM paravirtualized clock" 509 select PARAVIRT 510 select PARAVIRT_CLOCK 511 ---help--- 512 Turning on this option will allow you to run a paravirtualized clock 513 when running over the KVM hypervisor. Instead of relying on a PIT 514 (or probably other) emulation by the underlying device model, the host 515 provides the guest with timing infrastructure such as time of day, and 516 system time 517 518config KVM_GUEST 519 bool "KVM Guest support" 520 select PARAVIRT 521 ---help--- 522 This option enables various optimizations for running under the KVM 523 hypervisor. 524 525source "arch/x86/lguest/Kconfig" 526 527config PARAVIRT 528 bool "Enable paravirtualization code" 529 ---help--- 530 This changes the kernel so it can modify itself when it is run 531 under a hypervisor, potentially improving performance significantly 532 over full virtualization. However, when run without a hypervisor 533 the kernel is theoretically slower and slightly larger. 534 535config PARAVIRT_SPINLOCKS 536 bool "Paravirtualization layer for spinlocks" 537 depends on PARAVIRT && SMP && EXPERIMENTAL 538 ---help--- 539 Paravirtualized spinlocks allow a pvops backend to replace the 540 spinlock implementation with something virtualization-friendly 541 (for example, block the virtual CPU rather than spinning). 542 543 Unfortunately the downside is an up to 5% performance hit on 544 native kernels, with various workloads. 545 546 If you are unsure how to answer this question, answer N. 547 548config PARAVIRT_CLOCK 549 bool 550 default n 551 552endif 553 554config PARAVIRT_DEBUG 555 bool "paravirt-ops debugging" 556 depends on PARAVIRT && DEBUG_KERNEL 557 ---help--- 558 Enable to debug paravirt_ops internals. Specifically, BUG if 559 a paravirt_op is missing when it is called. 560 561config MEMTEST 562 bool "Memtest" 563 ---help--- 564 This option adds a kernel parameter 'memtest', which allows memtest 565 to be set. 566 memtest=0, mean disabled; -- default 567 memtest=1, mean do 1 test pattern; 568 ... 569 memtest=4, mean do 4 test patterns. 570 If you are unsure how to answer this question, answer N. 571 572config X86_SUMMIT_NUMA 573 def_bool y 574 depends on X86_32 && NUMA && X86_32_NON_STANDARD 575 576config X86_CYCLONE_TIMER 577 def_bool y 578 depends on X86_32_NON_STANDARD 579 580source "arch/x86/Kconfig.cpu" 581 582config HPET_TIMER 583 def_bool X86_64 584 prompt "HPET Timer Support" if X86_32 585 ---help--- 586 Use the IA-PC HPET (High Precision Event Timer) to manage 587 time in preference to the PIT and RTC, if a HPET is 588 present. 589 HPET is the next generation timer replacing legacy 8254s. 590 The HPET provides a stable time base on SMP 591 systems, unlike the TSC, but it is more expensive to access, 592 as it is off-chip. You can find the HPET spec at 593 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 594 595 You can safely choose Y here. However, HPET will only be 596 activated if the platform and the BIOS support this feature. 597 Otherwise the 8254 will be used for timing services. 598 599 Choose N to continue using the legacy 8254 timer. 600 601config HPET_EMULATE_RTC 602 def_bool y 603 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 604 605# Mark as embedded because too many people got it wrong. 606# The code disables itself when not needed. 607config DMI 608 default y 609 bool "Enable DMI scanning" if EMBEDDED 610 ---help--- 611 Enabled scanning of DMI to identify machine quirks. Say Y 612 here unless you have verified that your setup is not 613 affected by entries in the DMI blacklist. Required by PNP 614 BIOS code. 615 616config GART_IOMMU 617 bool "GART IOMMU support" if EMBEDDED 618 default y 619 select SWIOTLB 620 depends on X86_64 && PCI 621 ---help--- 622 Support for full DMA access of devices with 32bit memory access only 623 on systems with more than 3GB. This is usually needed for USB, 624 sound, many IDE/SATA chipsets and some other devices. 625 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART 626 based hardware IOMMU and a software bounce buffer based IOMMU used 627 on Intel systems and as fallback. 628 The code is only active when needed (enough memory and limited 629 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified 630 too. 631 632config CALGARY_IOMMU 633 bool "IBM Calgary IOMMU support" 634 select SWIOTLB 635 depends on X86_64 && PCI && EXPERIMENTAL 636 ---help--- 637 Support for hardware IOMMUs in IBM's xSeries x366 and x460 638 systems. Needed to run systems with more than 3GB of memory 639 properly with 32-bit PCI devices that do not support DAC 640 (Double Address Cycle). Calgary also supports bus level 641 isolation, where all DMAs pass through the IOMMU. This 642 prevents them from going anywhere except their intended 643 destination. This catches hard-to-find kernel bugs and 644 mis-behaving drivers and devices that do not use the DMA-API 645 properly to set up their DMA buffers. The IOMMU can be 646 turned off at boot time with the iommu=off parameter. 647 Normally the kernel will make the right choice by itself. 648 If unsure, say Y. 649 650config CALGARY_IOMMU_ENABLED_BY_DEFAULT 651 def_bool y 652 prompt "Should Calgary be enabled by default?" 653 depends on CALGARY_IOMMU 654 ---help--- 655 Should Calgary be enabled by default? if you choose 'y', Calgary 656 will be used (if it exists). If you choose 'n', Calgary will not be 657 used even if it exists. If you choose 'n' and would like to use 658 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 659 If unsure, say Y. 660 661config AMD_IOMMU 662 bool "AMD IOMMU support" 663 select SWIOTLB 664 select PCI_MSI 665 depends on X86_64 && PCI && ACPI 666 ---help--- 667 With this option you can enable support for AMD IOMMU hardware in 668 your system. An IOMMU is a hardware component which provides 669 remapping of DMA memory accesses from devices. With an AMD IOMMU you 670 can isolate the the DMA memory of different devices and protect the 671 system from misbehaving device drivers or hardware. 672 673 You can find out if your system has an AMD IOMMU if you look into 674 your BIOS for an option to enable it or if you have an IVRS ACPI 675 table. 676 677config AMD_IOMMU_STATS 678 bool "Export AMD IOMMU statistics to debugfs" 679 depends on AMD_IOMMU 680 select DEBUG_FS 681 ---help--- 682 This option enables code in the AMD IOMMU driver to collect various 683 statistics about whats happening in the driver and exports that 684 information to userspace via debugfs. 685 If unsure, say N. 686 687# need this always selected by IOMMU for the VIA workaround 688config SWIOTLB 689 def_bool y if X86_64 690 ---help--- 691 Support for software bounce buffers used on x86-64 systems 692 which don't have a hardware IOMMU (e.g. the current generation 693 of Intel's x86-64 CPUs). Using this PCI devices which can only 694 access 32-bits of memory can be used on systems with more than 695 3 GB of memory. If unsure, say Y. 696 697config IOMMU_HELPER 698 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU) 699 700config IOMMU_API 701 def_bool (AMD_IOMMU || DMAR) 702 703config MAXSMP 704 bool "Configure Maximum number of SMP Processors and NUMA Nodes" 705 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL 706 select CPUMASK_OFFSTACK 707 default n 708 ---help--- 709 Configure maximum number of CPUS and NUMA Nodes for this architecture. 710 If unsure, say N. 711 712config NR_CPUS 713 int "Maximum number of CPUs" if SMP && !MAXSMP 714 range 2 8 if SMP && X86_32 && !X86_BIGSMP 715 range 2 512 if SMP && !MAXSMP 716 default "1" if !SMP 717 default "4096" if MAXSMP 718 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000) 719 default "8" if SMP 720 ---help--- 721 This allows you to specify the maximum number of CPUs which this 722 kernel will support. The maximum supported value is 512 and the 723 minimum value which makes sense is 2. 724 725 This is purely to save memory - each supported CPU adds 726 approximately eight kilobytes to the kernel image. 727 728config SCHED_SMT 729 bool "SMT (Hyperthreading) scheduler support" 730 depends on X86_HT 731 ---help--- 732 SMT scheduler support improves the CPU scheduler's decision making 733 when dealing with Intel Pentium 4 chips with HyperThreading at a 734 cost of slightly increased overhead in some places. If unsure say 735 N here. 736 737config SCHED_MC 738 def_bool y 739 prompt "Multi-core scheduler support" 740 depends on X86_HT 741 ---help--- 742 Multi-core scheduler support improves the CPU scheduler's decision 743 making when dealing with multi-core CPU chips at a cost of slightly 744 increased overhead in some places. If unsure say N here. 745 746source "kernel/Kconfig.preempt" 747 748config X86_UP_APIC 749 bool "Local APIC support on uniprocessors" 750 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 751 ---help--- 752 A local APIC (Advanced Programmable Interrupt Controller) is an 753 integrated interrupt controller in the CPU. If you have a single-CPU 754 system which has a processor with a local APIC, you can say Y here to 755 enable and use it. If you say Y here even though your machine doesn't 756 have a local APIC, then the kernel will still run with no slowdown at 757 all. The local APIC supports CPU-generated self-interrupts (timer, 758 performance counters), and the NMI watchdog which detects hard 759 lockups. 760 761config X86_UP_IOAPIC 762 bool "IO-APIC support on uniprocessors" 763 depends on X86_UP_APIC 764 ---help--- 765 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 766 SMP-capable replacement for PC-style interrupt controllers. Most 767 SMP systems and many recent uniprocessor systems have one. 768 769 If you have a single-CPU system with an IO-APIC, you can say Y here 770 to use it. If you say Y here even though your machine doesn't have 771 an IO-APIC, then the kernel will still run with no slowdown at all. 772 773config X86_LOCAL_APIC 774 def_bool y 775 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC 776 777config X86_IO_APIC 778 def_bool y 779 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC 780 781config X86_VISWS_APIC 782 def_bool y 783 depends on X86_32 && X86_VISWS 784 785config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 786 bool "Reroute for broken boot IRQs" 787 default n 788 depends on X86_IO_APIC 789 ---help--- 790 This option enables a workaround that fixes a source of 791 spurious interrupts. This is recommended when threaded 792 interrupt handling is used on systems where the generation of 793 superfluous "boot interrupts" cannot be disabled. 794 795 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 796 entry in the chipset's IO-APIC is masked (as, e.g. the RT 797 kernel does during interrupt handling). On chipsets where this 798 boot IRQ generation cannot be disabled, this workaround keeps 799 the original IRQ line masked so that only the equivalent "boot 800 IRQ" is delivered to the CPUs. The workaround also tells the 801 kernel to set up the IRQ handler on the boot IRQ line. In this 802 way only one interrupt is delivered to the kernel. Otherwise 803 the spurious second interrupt may cause the kernel to bring 804 down (vital) interrupt lines. 805 806 Only affects "broken" chipsets. Interrupt sharing may be 807 increased on these systems. 808 809config X86_MCE 810 bool "Machine Check / overheating reporting" 811 ---help--- 812 Machine Check support allows the processor to notify the 813 kernel if it detects a problem (e.g. overheating, data corruption). 814 The action the kernel takes depends on the severity of the problem, 815 ranging from warning messages to halting the machine. 816 817config X86_MCE_INTEL 818 def_bool y 819 prompt "Intel MCE features" 820 depends on X86_MCE && X86_LOCAL_APIC 821 ---help--- 822 Additional support for intel specific MCE features such as 823 the thermal monitor. 824 825config X86_MCE_AMD 826 def_bool y 827 prompt "AMD MCE features" 828 depends on X86_MCE && X86_LOCAL_APIC 829 ---help--- 830 Additional support for AMD specific MCE features such as 831 the DRAM Error Threshold. 832 833config X86_ANCIENT_MCE 834 def_bool n 835 depends on X86_32 && X86_MCE 836 prompt "Support for old Pentium 5 / WinChip machine checks" 837 ---help--- 838 Include support for machine check handling on old Pentium 5 or WinChip 839 systems. These typically need to be enabled explicitely on the command 840 line. 841 842config X86_MCE_THRESHOLD 843 depends on X86_MCE_AMD || X86_MCE_INTEL 844 bool 845 default y 846 847config X86_MCE_INJECT 848 depends on X86_MCE 849 tristate "Machine check injector support" 850 ---help--- 851 Provide support for injecting machine checks for testing purposes. 852 If you don't know what a machine check is and you don't do kernel 853 QA it is safe to say n. 854 855config X86_THERMAL_VECTOR 856 def_bool y 857 depends on X86_MCE_INTEL 858 859config VM86 860 bool "Enable VM86 support" if EMBEDDED 861 default y 862 depends on X86_32 863 ---help--- 864 This option is required by programs like DOSEMU to run 16-bit legacy 865 code on X86 processors. It also may be needed by software like 866 XFree86 to initialize some video cards via BIOS. Disabling this 867 option saves about 6k. 868 869config TOSHIBA 870 tristate "Toshiba Laptop support" 871 depends on X86_32 872 ---help--- 873 This adds a driver to safely access the System Management Mode of 874 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 875 not work on models with a Phoenix BIOS. The System Management Mode 876 is used to set the BIOS and power saving options on Toshiba portables. 877 878 For information on utilities to make use of this driver see the 879 Toshiba Linux utilities web site at: 880 <http://www.buzzard.org.uk/toshiba/>. 881 882 Say Y if you intend to run this kernel on a Toshiba portable. 883 Say N otherwise. 884 885config I8K 886 tristate "Dell laptop support" 887 ---help--- 888 This adds a driver to safely access the System Management Mode 889 of the CPU on the Dell Inspiron 8000. The System Management Mode 890 is used to read cpu temperature and cooling fan status and to 891 control the fans on the I8K portables. 892 893 This driver has been tested only on the Inspiron 8000 but it may 894 also work with other Dell laptops. You can force loading on other 895 models by passing the parameter `force=1' to the module. Use at 896 your own risk. 897 898 For information on utilities to make use of this driver see the 899 I8K Linux utilities web site at: 900 <http://people.debian.org/~dz/i8k/> 901 902 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 903 Say N otherwise. 904 905config X86_REBOOTFIXUPS 906 bool "Enable X86 board specific fixups for reboot" 907 depends on X86_32 908 ---help--- 909 This enables chipset and/or board specific fixups to be done 910 in order to get reboot to work correctly. This is only needed on 911 some combinations of hardware and BIOS. The symptom, for which 912 this config is intended, is when reboot ends with a stalled/hung 913 system. 914 915 Currently, the only fixup is for the Geode machines using 916 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 917 918 Say Y if you want to enable the fixup. Currently, it's safe to 919 enable this option even if you don't need it. 920 Say N otherwise. 921 922config MICROCODE 923 tristate "/dev/cpu/microcode - microcode support" 924 select FW_LOADER 925 ---help--- 926 If you say Y here, you will be able to update the microcode on 927 certain Intel and AMD processors. The Intel support is for the 928 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, 929 Pentium 4, Xeon etc. The AMD support is for family 0x10 and 930 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra. 931 You will obviously need the actual microcode binary data itself 932 which is not shipped with the Linux kernel. 933 934 This option selects the general module only, you need to select 935 at least one vendor specific module as well. 936 937 To compile this driver as a module, choose M here: the 938 module will be called microcode. 939 940config MICROCODE_INTEL 941 bool "Intel microcode patch loading support" 942 depends on MICROCODE 943 default MICROCODE 944 select FW_LOADER 945 ---help--- 946 This options enables microcode patch loading support for Intel 947 processors. 948 949 For latest news and information on obtaining all the required 950 Intel ingredients for this driver, check: 951 <http://www.urbanmyth.org/microcode/>. 952 953config MICROCODE_AMD 954 bool "AMD microcode patch loading support" 955 depends on MICROCODE 956 select FW_LOADER 957 ---help--- 958 If you select this option, microcode patch loading support for AMD 959 processors will be enabled. 960 961config MICROCODE_OLD_INTERFACE 962 def_bool y 963 depends on MICROCODE 964 965config X86_MSR 966 tristate "/dev/cpu/*/msr - Model-specific register support" 967 ---help--- 968 This device gives privileged processes access to the x86 969 Model-Specific Registers (MSRs). It is a character device with 970 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 971 MSR accesses are directed to a specific CPU on multi-processor 972 systems. 973 974config X86_CPUID 975 tristate "/dev/cpu/*/cpuid - CPU information support" 976 ---help--- 977 This device gives processes access to the x86 CPUID instruction to 978 be executed on a specific processor. It is a character device 979 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 980 /dev/cpu/31/cpuid. 981 982config X86_CPU_DEBUG 983 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support" 984 ---help--- 985 If you select this option, this will provide various x86 CPUs 986 information through debugfs. 987 988choice 989 prompt "High Memory Support" 990 default HIGHMEM4G if !X86_NUMAQ 991 default HIGHMEM64G if X86_NUMAQ 992 depends on X86_32 993 994config NOHIGHMEM 995 bool "off" 996 depends on !X86_NUMAQ 997 ---help--- 998 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 999 However, the address space of 32-bit x86 processors is only 4 1000 Gigabytes large. That means that, if you have a large amount of 1001 physical memory, not all of it can be "permanently mapped" by the 1002 kernel. The physical memory that's not permanently mapped is called 1003 "high memory". 1004 1005 If you are compiling a kernel which will never run on a machine with 1006 more than 1 Gigabyte total physical RAM, answer "off" here (default 1007 choice and suitable for most users). This will result in a "3GB/1GB" 1008 split: 3GB are mapped so that each process sees a 3GB virtual memory 1009 space and the remaining part of the 4GB virtual memory space is used 1010 by the kernel to permanently map as much physical memory as 1011 possible. 1012 1013 If the machine has between 1 and 4 Gigabytes physical RAM, then 1014 answer "4GB" here. 1015 1016 If more than 4 Gigabytes is used then answer "64GB" here. This 1017 selection turns Intel PAE (Physical Address Extension) mode on. 1018 PAE implements 3-level paging on IA32 processors. PAE is fully 1019 supported by Linux, PAE mode is implemented on all recent Intel 1020 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1021 then the kernel will not boot on CPUs that don't support PAE! 1022 1023 The actual amount of total physical memory will either be 1024 auto detected or can be forced by using a kernel command line option 1025 such as "mem=256M". (Try "man bootparam" or see the documentation of 1026 your boot loader (lilo or loadlin) about how to pass options to the 1027 kernel at boot time.) 1028 1029 If unsure, say "off". 1030 1031config HIGHMEM4G 1032 bool "4GB" 1033 depends on !X86_NUMAQ 1034 ---help--- 1035 Select this if you have a 32-bit processor and between 1 and 4 1036 gigabytes of physical RAM. 1037 1038config HIGHMEM64G 1039 bool "64GB" 1040 depends on !M386 && !M486 1041 select X86_PAE 1042 ---help--- 1043 Select this if you have a 32-bit processor and more than 4 1044 gigabytes of physical RAM. 1045 1046endchoice 1047 1048choice 1049 depends on EXPERIMENTAL 1050 prompt "Memory split" if EMBEDDED 1051 default VMSPLIT_3G 1052 depends on X86_32 1053 ---help--- 1054 Select the desired split between kernel and user memory. 1055 1056 If the address range available to the kernel is less than the 1057 physical memory installed, the remaining memory will be available 1058 as "high memory". Accessing high memory is a little more costly 1059 than low memory, as it needs to be mapped into the kernel first. 1060 Note that increasing the kernel address space limits the range 1061 available to user programs, making the address space there 1062 tighter. Selecting anything other than the default 3G/1G split 1063 will also likely make your kernel incompatible with binary-only 1064 kernel modules. 1065 1066 If you are not absolutely sure what you are doing, leave this 1067 option alone! 1068 1069 config VMSPLIT_3G 1070 bool "3G/1G user/kernel split" 1071 config VMSPLIT_3G_OPT 1072 depends on !X86_PAE 1073 bool "3G/1G user/kernel split (for full 1G low memory)" 1074 config VMSPLIT_2G 1075 bool "2G/2G user/kernel split" 1076 config VMSPLIT_2G_OPT 1077 depends on !X86_PAE 1078 bool "2G/2G user/kernel split (for full 2G low memory)" 1079 config VMSPLIT_1G 1080 bool "1G/3G user/kernel split" 1081endchoice 1082 1083config PAGE_OFFSET 1084 hex 1085 default 0xB0000000 if VMSPLIT_3G_OPT 1086 default 0x80000000 if VMSPLIT_2G 1087 default 0x78000000 if VMSPLIT_2G_OPT 1088 default 0x40000000 if VMSPLIT_1G 1089 default 0xC0000000 1090 depends on X86_32 1091 1092config HIGHMEM 1093 def_bool y 1094 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1095 1096config X86_PAE 1097 bool "PAE (Physical Address Extension) Support" 1098 depends on X86_32 && !HIGHMEM4G 1099 ---help--- 1100 PAE is required for NX support, and furthermore enables 1101 larger swapspace support for non-overcommit purposes. It 1102 has the cost of more pagetable lookup overhead, and also 1103 consumes more pagetable space per process. 1104 1105config ARCH_PHYS_ADDR_T_64BIT 1106 def_bool X86_64 || X86_PAE 1107 1108config DIRECT_GBPAGES 1109 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED 1110 default y 1111 depends on X86_64 1112 ---help--- 1113 Allow the kernel linear mapping to use 1GB pages on CPUs that 1114 support it. This can improve the kernel's performance a tiny bit by 1115 reducing TLB pressure. If in doubt, say "Y". 1116 1117# Common NUMA Features 1118config NUMA 1119 bool "Numa Memory Allocation and Scheduler Support" 1120 depends on SMP 1121 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL) 1122 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP) 1123 ---help--- 1124 Enable NUMA (Non Uniform Memory Access) support. 1125 1126 The kernel will try to allocate memory used by a CPU on the 1127 local memory controller of the CPU and add some more 1128 NUMA awareness to the kernel. 1129 1130 For 64-bit this is recommended if the system is Intel Core i7 1131 (or later), AMD Opteron, or EM64T NUMA. 1132 1133 For 32-bit this is only needed on (rare) 32-bit-only platforms 1134 that support NUMA topologies, such as NUMAQ / Summit, or if you 1135 boot a 32-bit kernel on a 64-bit NUMA platform. 1136 1137 Otherwise, you should say N. 1138 1139comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 1140 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI) 1141 1142config K8_NUMA 1143 def_bool y 1144 prompt "Old style AMD Opteron NUMA detection" 1145 depends on X86_64 && NUMA && PCI 1146 ---help--- 1147 Enable K8 NUMA node topology detection. You should say Y here if 1148 you have a multi processor AMD K8 system. This uses an old 1149 method to read the NUMA configuration directly from the builtin 1150 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA 1151 instead, which also takes priority if both are compiled in. 1152 1153config X86_64_ACPI_NUMA 1154 def_bool y 1155 prompt "ACPI NUMA detection" 1156 depends on X86_64 && NUMA && ACPI && PCI 1157 select ACPI_NUMA 1158 ---help--- 1159 Enable ACPI SRAT based node topology detection. 1160 1161# Some NUMA nodes have memory ranges that span 1162# other nodes. Even though a pfn is valid and 1163# between a node's start and end pfns, it may not 1164# reside on that node. See memmap_init_zone() 1165# for details. 1166config NODES_SPAN_OTHER_NODES 1167 def_bool y 1168 depends on X86_64_ACPI_NUMA 1169 1170config NUMA_EMU 1171 bool "NUMA emulation" 1172 depends on X86_64 && NUMA 1173 ---help--- 1174 Enable NUMA emulation. A flat machine will be split 1175 into virtual nodes when booted with "numa=fake=N", where N is the 1176 number of nodes. This is only useful for debugging. 1177 1178config NODES_SHIFT 1179 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1180 range 1 9 1181 default "9" if MAXSMP 1182 default "6" if X86_64 1183 default "4" if X86_NUMAQ 1184 default "3" 1185 depends on NEED_MULTIPLE_NODES 1186 ---help--- 1187 Specify the maximum number of NUMA Nodes available on the target 1188 system. Increases memory reserved to accommodate various tables. 1189 1190config HAVE_ARCH_BOOTMEM 1191 def_bool y 1192 depends on X86_32 && NUMA 1193 1194config ARCH_HAVE_MEMORY_PRESENT 1195 def_bool y 1196 depends on X86_32 && DISCONTIGMEM 1197 1198config NEED_NODE_MEMMAP_SIZE 1199 def_bool y 1200 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1201 1202config HAVE_ARCH_ALLOC_REMAP 1203 def_bool y 1204 depends on X86_32 && NUMA 1205 1206config ARCH_FLATMEM_ENABLE 1207 def_bool y 1208 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA 1209 1210config ARCH_DISCONTIGMEM_ENABLE 1211 def_bool y 1212 depends on NUMA && X86_32 1213 1214config ARCH_DISCONTIGMEM_DEFAULT 1215 def_bool y 1216 depends on NUMA && X86_32 1217 1218config ARCH_PROC_KCORE_TEXT 1219 def_bool y 1220 depends on X86_64 && PROC_KCORE 1221 1222config ARCH_SPARSEMEM_DEFAULT 1223 def_bool y 1224 depends on X86_64 1225 1226config ARCH_SPARSEMEM_ENABLE 1227 def_bool y 1228 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD 1229 select SPARSEMEM_STATIC if X86_32 1230 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1231 1232config ARCH_SELECT_MEMORY_MODEL 1233 def_bool y 1234 depends on ARCH_SPARSEMEM_ENABLE 1235 1236config ARCH_MEMORY_PROBE 1237 def_bool X86_64 1238 depends on MEMORY_HOTPLUG 1239 1240source "mm/Kconfig" 1241 1242config HIGHPTE 1243 bool "Allocate 3rd-level pagetables from highmem" 1244 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G) 1245 ---help--- 1246 The VM uses one page table entry for each page of physical memory. 1247 For systems with a lot of RAM, this can be wasteful of precious 1248 low memory. Setting this option will put user-space page table 1249 entries in high memory. 1250 1251config X86_CHECK_BIOS_CORRUPTION 1252 bool "Check for low memory corruption" 1253 ---help--- 1254 Periodically check for memory corruption in low memory, which 1255 is suspected to be caused by BIOS. Even when enabled in the 1256 configuration, it is disabled at runtime. Enable it by 1257 setting "memory_corruption_check=1" on the kernel command 1258 line. By default it scans the low 64k of memory every 60 1259 seconds; see the memory_corruption_check_size and 1260 memory_corruption_check_period parameters in 1261 Documentation/kernel-parameters.txt to adjust this. 1262 1263 When enabled with the default parameters, this option has 1264 almost no overhead, as it reserves a relatively small amount 1265 of memory and scans it infrequently. It both detects corruption 1266 and prevents it from affecting the running system. 1267 1268 It is, however, intended as a diagnostic tool; if repeatable 1269 BIOS-originated corruption always affects the same memory, 1270 you can use memmap= to prevent the kernel from using that 1271 memory. 1272 1273config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1274 bool "Set the default setting of memory_corruption_check" 1275 depends on X86_CHECK_BIOS_CORRUPTION 1276 default y 1277 ---help--- 1278 Set whether the default state of memory_corruption_check is 1279 on or off. 1280 1281config X86_RESERVE_LOW_64K 1282 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen" 1283 default y 1284 ---help--- 1285 Reserve the first 64K of physical RAM on BIOSes that are known 1286 to potentially corrupt that memory range. A numbers of BIOSes are 1287 known to utilize this area during suspend/resume, so it must not 1288 be used by the kernel. 1289 1290 Set this to N if you are absolutely sure that you trust the BIOS 1291 to get all its memory reservations and usages right. 1292 1293 If you have doubts about the BIOS (e.g. suspend/resume does not 1294 work or there's kernel crashes after certain hardware hotplug 1295 events) and it's not AMI or Phoenix, then you might want to enable 1296 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical 1297 corruption patterns. 1298 1299 Say Y if unsure. 1300 1301config MATH_EMULATION 1302 bool 1303 prompt "Math emulation" if X86_32 1304 ---help--- 1305 Linux can emulate a math coprocessor (used for floating point 1306 operations) if you don't have one. 486DX and Pentium processors have 1307 a math coprocessor built in, 486SX and 386 do not, unless you added 1308 a 487DX or 387, respectively. (The messages during boot time can 1309 give you some hints here ["man dmesg"].) Everyone needs either a 1310 coprocessor or this emulation. 1311 1312 If you don't have a math coprocessor, you need to say Y here; if you 1313 say Y here even though you have a coprocessor, the coprocessor will 1314 be used nevertheless. (This behavior can be changed with the kernel 1315 command line option "no387", which comes handy if your coprocessor 1316 is broken. Try "man bootparam" or see the documentation of your boot 1317 loader (lilo or loadlin) about how to pass options to the kernel at 1318 boot time.) This means that it is a good idea to say Y here if you 1319 intend to use this kernel on different machines. 1320 1321 More information about the internals of the Linux math coprocessor 1322 emulation can be found in <file:arch/x86/math-emu/README>. 1323 1324 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1325 kernel, it won't hurt. 1326 1327config MTRR 1328 bool "MTRR (Memory Type Range Register) support" 1329 ---help--- 1330 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1331 the Memory Type Range Registers (MTRRs) may be used to control 1332 processor access to memory ranges. This is most useful if you have 1333 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1334 allows bus write transfers to be combined into a larger transfer 1335 before bursting over the PCI/AGP bus. This can increase performance 1336 of image write operations 2.5 times or more. Saying Y here creates a 1337 /proc/mtrr file which may be used to manipulate your processor's 1338 MTRRs. Typically the X server should use this. 1339 1340 This code has a reasonably generic interface so that similar 1341 control registers on other processors can be easily supported 1342 as well: 1343 1344 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1345 Registers (ARRs) which provide a similar functionality to MTRRs. For 1346 these, the ARRs are used to emulate the MTRRs. 1347 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1348 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1349 write-combining. All of these processors are supported by this code 1350 and it makes sense to say Y here if you have one of them. 1351 1352 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1353 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1354 can lead to all sorts of problems, so it's good to say Y here. 1355 1356 You can safely say Y even if your machine doesn't have MTRRs, you'll 1357 just add about 9 KB to your kernel. 1358 1359 See <file:Documentation/x86/mtrr.txt> for more information. 1360 1361config MTRR_SANITIZER 1362 def_bool y 1363 prompt "MTRR cleanup support" 1364 depends on MTRR 1365 ---help--- 1366 Convert MTRR layout from continuous to discrete, so X drivers can 1367 add writeback entries. 1368 1369 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1370 The largest mtrr entry size for a continuous block can be set with 1371 mtrr_chunk_size. 1372 1373 If unsure, say Y. 1374 1375config MTRR_SANITIZER_ENABLE_DEFAULT 1376 int "MTRR cleanup enable value (0-1)" 1377 range 0 1 1378 default "0" 1379 depends on MTRR_SANITIZER 1380 ---help--- 1381 Enable mtrr cleanup default value 1382 1383config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1384 int "MTRR cleanup spare reg num (0-7)" 1385 range 0 7 1386 default "1" 1387 depends on MTRR_SANITIZER 1388 ---help--- 1389 mtrr cleanup spare entries default, it can be changed via 1390 mtrr_spare_reg_nr=N on the kernel command line. 1391 1392config X86_PAT 1393 bool 1394 prompt "x86 PAT support" 1395 depends on MTRR 1396 ---help--- 1397 Use PAT attributes to setup page level cache control. 1398 1399 PATs are the modern equivalents of MTRRs and are much more 1400 flexible than MTRRs. 1401 1402 Say N here if you see bootup problems (boot crash, boot hang, 1403 spontaneous reboots) or a non-working video driver. 1404 1405 If unsure, say Y. 1406 1407config ARCH_USES_PG_UNCACHED 1408 def_bool y 1409 depends on X86_PAT 1410 1411config EFI 1412 bool "EFI runtime service support" 1413 depends on ACPI 1414 ---help--- 1415 This enables the kernel to use EFI runtime services that are 1416 available (such as the EFI variable services). 1417 1418 This option is only useful on systems that have EFI firmware. 1419 In addition, you should use the latest ELILO loader available 1420 at <http://elilo.sourceforge.net> in order to take advantage 1421 of EFI runtime services. However, even with this option, the 1422 resultant kernel should continue to boot on existing non-EFI 1423 platforms. 1424 1425config SECCOMP 1426 def_bool y 1427 prompt "Enable seccomp to safely compute untrusted bytecode" 1428 ---help--- 1429 This kernel feature is useful for number crunching applications 1430 that may need to compute untrusted bytecode during their 1431 execution. By using pipes or other transports made available to 1432 the process as file descriptors supporting the read/write 1433 syscalls, it's possible to isolate those applications in 1434 their own address space using seccomp. Once seccomp is 1435 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1436 and the task is only allowed to execute a few safe syscalls 1437 defined by each seccomp mode. 1438 1439 If unsure, say Y. Only embedded should say N here. 1440 1441config CC_STACKPROTECTOR_ALL 1442 bool 1443 1444config CC_STACKPROTECTOR 1445 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" 1446 select CC_STACKPROTECTOR_ALL 1447 ---help--- 1448 This option turns on the -fstack-protector GCC feature. This 1449 feature puts, at the beginning of functions, a canary value on 1450 the stack just before the return address, and validates 1451 the value just before actually returning. Stack based buffer 1452 overflows (that need to overwrite this return address) now also 1453 overwrite the canary, which gets detected and the attack is then 1454 neutralized via a kernel panic. 1455 1456 This feature requires gcc version 4.2 or above, or a distribution 1457 gcc with the feature backported. Older versions are automatically 1458 detected and for those versions, this configuration option is 1459 ignored. (and a warning is printed during bootup) 1460 1461source kernel/Kconfig.hz 1462 1463config KEXEC 1464 bool "kexec system call" 1465 ---help--- 1466 kexec is a system call that implements the ability to shutdown your 1467 current kernel, and to start another kernel. It is like a reboot 1468 but it is independent of the system firmware. And like a reboot 1469 you can start any kernel with it, not just Linux. 1470 1471 The name comes from the similarity to the exec system call. 1472 1473 It is an ongoing process to be certain the hardware in a machine 1474 is properly shutdown, so do not be surprised if this code does not 1475 initially work for you. It may help to enable device hotplugging 1476 support. As of this writing the exact hardware interface is 1477 strongly in flux, so no good recommendation can be made. 1478 1479config CRASH_DUMP 1480 bool "kernel crash dumps" 1481 depends on X86_64 || (X86_32 && HIGHMEM) 1482 ---help--- 1483 Generate crash dump after being started by kexec. 1484 This should be normally only set in special crash dump kernels 1485 which are loaded in the main kernel with kexec-tools into 1486 a specially reserved region and then later executed after 1487 a crash by kdump/kexec. The crash dump kernel must be compiled 1488 to a memory address not used by the main kernel or BIOS using 1489 PHYSICAL_START, or it must be built as a relocatable image 1490 (CONFIG_RELOCATABLE=y). 1491 For more details see Documentation/kdump/kdump.txt 1492 1493config KEXEC_JUMP 1494 bool "kexec jump (EXPERIMENTAL)" 1495 depends on EXPERIMENTAL 1496 depends on KEXEC && HIBERNATION 1497 ---help--- 1498 Jump between original kernel and kexeced kernel and invoke 1499 code in physical address mode via KEXEC 1500 1501config PHYSICAL_START 1502 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) 1503 default "0x1000000" 1504 ---help--- 1505 This gives the physical address where the kernel is loaded. 1506 1507 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1508 bzImage will decompress itself to above physical address and 1509 run from there. Otherwise, bzImage will run from the address where 1510 it has been loaded by the boot loader and will ignore above physical 1511 address. 1512 1513 In normal kdump cases one does not have to set/change this option 1514 as now bzImage can be compiled as a completely relocatable image 1515 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1516 address. This option is mainly useful for the folks who don't want 1517 to use a bzImage for capturing the crash dump and want to use a 1518 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1519 to be specifically compiled to run from a specific memory area 1520 (normally a reserved region) and this option comes handy. 1521 1522 So if you are using bzImage for capturing the crash dump, 1523 leave the value here unchanged to 0x1000000 and set 1524 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1525 for capturing the crash dump change this value to start of 1526 the reserved region. In other words, it can be set based on 1527 the "X" value as specified in the "crashkernel=YM@XM" 1528 command line boot parameter passed to the panic-ed 1529 kernel. Please take a look at Documentation/kdump/kdump.txt 1530 for more details about crash dumps. 1531 1532 Usage of bzImage for capturing the crash dump is recommended as 1533 one does not have to build two kernels. Same kernel can be used 1534 as production kernel and capture kernel. Above option should have 1535 gone away after relocatable bzImage support is introduced. But it 1536 is present because there are users out there who continue to use 1537 vmlinux for dump capture. This option should go away down the 1538 line. 1539 1540 Don't change this unless you know what you are doing. 1541 1542config RELOCATABLE 1543 bool "Build a relocatable kernel" 1544 default y 1545 ---help--- 1546 This builds a kernel image that retains relocation information 1547 so it can be loaded someplace besides the default 1MB. 1548 The relocations tend to make the kernel binary about 10% larger, 1549 but are discarded at runtime. 1550 1551 One use is for the kexec on panic case where the recovery kernel 1552 must live at a different physical address than the primary 1553 kernel. 1554 1555 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1556 it has been loaded at and the compile time physical address 1557 (CONFIG_PHYSICAL_START) is ignored. 1558 1559# Relocation on x86-32 needs some additional build support 1560config X86_NEED_RELOCS 1561 def_bool y 1562 depends on X86_32 && RELOCATABLE 1563 1564config PHYSICAL_ALIGN 1565 hex 1566 prompt "Alignment value to which kernel should be aligned" if X86_32 1567 default "0x1000000" 1568 range 0x2000 0x1000000 1569 ---help--- 1570 This value puts the alignment restrictions on physical address 1571 where kernel is loaded and run from. Kernel is compiled for an 1572 address which meets above alignment restriction. 1573 1574 If bootloader loads the kernel at a non-aligned address and 1575 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1576 address aligned to above value and run from there. 1577 1578 If bootloader loads the kernel at a non-aligned address and 1579 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1580 load address and decompress itself to the address it has been 1581 compiled for and run from there. The address for which kernel is 1582 compiled already meets above alignment restrictions. Hence the 1583 end result is that kernel runs from a physical address meeting 1584 above alignment restrictions. 1585 1586 Don't change this unless you know what you are doing. 1587 1588config HOTPLUG_CPU 1589 bool "Support for hot-pluggable CPUs" 1590 depends on SMP && HOTPLUG 1591 ---help--- 1592 Say Y here to allow turning CPUs off and on. CPUs can be 1593 controlled through /sys/devices/system/cpu. 1594 ( Note: power management support will enable this option 1595 automatically on SMP systems. ) 1596 Say N if you want to disable CPU hotplug. 1597 1598config COMPAT_VDSO 1599 def_bool y 1600 prompt "Compat VDSO support" 1601 depends on X86_32 || IA32_EMULATION 1602 ---help--- 1603 Map the 32-bit VDSO to the predictable old-style address too. 1604 ---help--- 1605 Say N here if you are running a sufficiently recent glibc 1606 version (2.3.3 or later), to remove the high-mapped 1607 VDSO mapping and to exclusively use the randomized VDSO. 1608 1609 If unsure, say Y. 1610 1611config CMDLINE_BOOL 1612 bool "Built-in kernel command line" 1613 default n 1614 ---help--- 1615 Allow for specifying boot arguments to the kernel at 1616 build time. On some systems (e.g. embedded ones), it is 1617 necessary or convenient to provide some or all of the 1618 kernel boot arguments with the kernel itself (that is, 1619 to not rely on the boot loader to provide them.) 1620 1621 To compile command line arguments into the kernel, 1622 set this option to 'Y', then fill in the 1623 the boot arguments in CONFIG_CMDLINE. 1624 1625 Systems with fully functional boot loaders (i.e. non-embedded) 1626 should leave this option set to 'N'. 1627 1628config CMDLINE 1629 string "Built-in kernel command string" 1630 depends on CMDLINE_BOOL 1631 default "" 1632 ---help--- 1633 Enter arguments here that should be compiled into the kernel 1634 image and used at boot time. If the boot loader provides a 1635 command line at boot time, it is appended to this string to 1636 form the full kernel command line, when the system boots. 1637 1638 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1639 change this behavior. 1640 1641 In most cases, the command line (whether built-in or provided 1642 by the boot loader) should specify the device for the root 1643 file system. 1644 1645config CMDLINE_OVERRIDE 1646 bool "Built-in command line overrides boot loader arguments" 1647 default n 1648 depends on CMDLINE_BOOL 1649 ---help--- 1650 Set this option to 'Y' to have the kernel ignore the boot loader 1651 command line, and use ONLY the built-in command line. 1652 1653 This is used to work around broken boot loaders. This should 1654 be set to 'N' under normal conditions. 1655 1656endmenu 1657 1658config ARCH_ENABLE_MEMORY_HOTPLUG 1659 def_bool y 1660 depends on X86_64 || (X86_32 && HIGHMEM) 1661 1662config ARCH_ENABLE_MEMORY_HOTREMOVE 1663 def_bool y 1664 depends on MEMORY_HOTPLUG 1665 1666config HAVE_ARCH_EARLY_PFN_TO_NID 1667 def_bool X86_64 1668 depends on NUMA 1669 1670menu "Power management and ACPI options" 1671 1672config ARCH_HIBERNATION_HEADER 1673 def_bool y 1674 depends on X86_64 && HIBERNATION 1675 1676source "kernel/power/Kconfig" 1677 1678source "drivers/acpi/Kconfig" 1679 1680source "drivers/sfi/Kconfig" 1681 1682config X86_APM_BOOT 1683 bool 1684 default y 1685 depends on APM || APM_MODULE 1686 1687menuconfig APM 1688 tristate "APM (Advanced Power Management) BIOS support" 1689 depends on X86_32 && PM_SLEEP 1690 ---help--- 1691 APM is a BIOS specification for saving power using several different 1692 techniques. This is mostly useful for battery powered laptops with 1693 APM compliant BIOSes. If you say Y here, the system time will be 1694 reset after a RESUME operation, the /proc/apm device will provide 1695 battery status information, and user-space programs will receive 1696 notification of APM "events" (e.g. battery status change). 1697 1698 If you select "Y" here, you can disable actual use of the APM 1699 BIOS by passing the "apm=off" option to the kernel at boot time. 1700 1701 Note that the APM support is almost completely disabled for 1702 machines with more than one CPU. 1703 1704 In order to use APM, you will need supporting software. For location 1705 and more information, read <file:Documentation/power/pm.txt> and the 1706 Battery Powered Linux mini-HOWTO, available from 1707 <http://www.tldp.org/docs.html#howto>. 1708 1709 This driver does not spin down disk drives (see the hdparm(8) 1710 manpage ("man 8 hdparm") for that), and it doesn't turn off 1711 VESA-compliant "green" monitors. 1712 1713 This driver does not support the TI 4000M TravelMate and the ACER 1714 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1715 desktop machines also don't have compliant BIOSes, and this driver 1716 may cause those machines to panic during the boot phase. 1717 1718 Generally, if you don't have a battery in your machine, there isn't 1719 much point in using this driver and you should say N. If you get 1720 random kernel OOPSes or reboots that don't seem to be related to 1721 anything, try disabling/enabling this option (or disabling/enabling 1722 APM in your BIOS). 1723 1724 Some other things you should try when experiencing seemingly random, 1725 "weird" problems: 1726 1727 1) make sure that you have enough swap space and that it is 1728 enabled. 1729 2) pass the "no-hlt" option to the kernel 1730 3) switch on floating point emulation in the kernel and pass 1731 the "no387" option to the kernel 1732 4) pass the "floppy=nodma" option to the kernel 1733 5) pass the "mem=4M" option to the kernel (thereby disabling 1734 all but the first 4 MB of RAM) 1735 6) make sure that the CPU is not over clocked. 1736 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1737 8) disable the cache from your BIOS settings 1738 9) install a fan for the video card or exchange video RAM 1739 10) install a better fan for the CPU 1740 11) exchange RAM chips 1741 12) exchange the motherboard. 1742 1743 To compile this driver as a module, choose M here: the 1744 module will be called apm. 1745 1746if APM 1747 1748config APM_IGNORE_USER_SUSPEND 1749 bool "Ignore USER SUSPEND" 1750 ---help--- 1751 This option will ignore USER SUSPEND requests. On machines with a 1752 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1753 series notebooks, it is necessary to say Y because of a BIOS bug. 1754 1755config APM_DO_ENABLE 1756 bool "Enable PM at boot time" 1757 ---help--- 1758 Enable APM features at boot time. From page 36 of the APM BIOS 1759 specification: "When disabled, the APM BIOS does not automatically 1760 power manage devices, enter the Standby State, enter the Suspend 1761 State, or take power saving steps in response to CPU Idle calls." 1762 This driver will make CPU Idle calls when Linux is idle (unless this 1763 feature is turned off -- see "Do CPU IDLE calls", below). This 1764 should always save battery power, but more complicated APM features 1765 will be dependent on your BIOS implementation. You may need to turn 1766 this option off if your computer hangs at boot time when using APM 1767 support, or if it beeps continuously instead of suspending. Turn 1768 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1769 T400CDT. This is off by default since most machines do fine without 1770 this feature. 1771 1772config APM_CPU_IDLE 1773 bool "Make CPU Idle calls when idle" 1774 ---help--- 1775 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1776 On some machines, this can activate improved power savings, such as 1777 a slowed CPU clock rate, when the machine is idle. These idle calls 1778 are made after the idle loop has run for some length of time (e.g., 1779 333 mS). On some machines, this will cause a hang at boot time or 1780 whenever the CPU becomes idle. (On machines with more than one CPU, 1781 this option does nothing.) 1782 1783config APM_DISPLAY_BLANK 1784 bool "Enable console blanking using APM" 1785 ---help--- 1786 Enable console blanking using the APM. Some laptops can use this to 1787 turn off the LCD backlight when the screen blanker of the Linux 1788 virtual console blanks the screen. Note that this is only used by 1789 the virtual console screen blanker, and won't turn off the backlight 1790 when using the X Window system. This also doesn't have anything to 1791 do with your VESA-compliant power-saving monitor. Further, this 1792 option doesn't work for all laptops -- it might not turn off your 1793 backlight at all, or it might print a lot of errors to the console, 1794 especially if you are using gpm. 1795 1796config APM_ALLOW_INTS 1797 bool "Allow interrupts during APM BIOS calls" 1798 ---help--- 1799 Normally we disable external interrupts while we are making calls to 1800 the APM BIOS as a measure to lessen the effects of a badly behaving 1801 BIOS implementation. The BIOS should reenable interrupts if it 1802 needs to. Unfortunately, some BIOSes do not -- especially those in 1803 many of the newer IBM Thinkpads. If you experience hangs when you 1804 suspend, try setting this to Y. Otherwise, say N. 1805 1806endif # APM 1807 1808source "arch/x86/kernel/cpu/cpufreq/Kconfig" 1809 1810source "drivers/cpuidle/Kconfig" 1811 1812source "drivers/idle/Kconfig" 1813 1814endmenu 1815 1816 1817menu "Bus options (PCI etc.)" 1818 1819config PCI 1820 bool "PCI support" 1821 default y 1822 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC) 1823 ---help--- 1824 Find out whether you have a PCI motherboard. PCI is the name of a 1825 bus system, i.e. the way the CPU talks to the other stuff inside 1826 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 1827 VESA. If you have PCI, say Y, otherwise N. 1828 1829choice 1830 prompt "PCI access mode" 1831 depends on X86_32 && PCI 1832 default PCI_GOANY 1833 ---help--- 1834 On PCI systems, the BIOS can be used to detect the PCI devices and 1835 determine their configuration. However, some old PCI motherboards 1836 have BIOS bugs and may crash if this is done. Also, some embedded 1837 PCI-based systems don't have any BIOS at all. Linux can also try to 1838 detect the PCI hardware directly without using the BIOS. 1839 1840 With this option, you can specify how Linux should detect the 1841 PCI devices. If you choose "BIOS", the BIOS will be used, 1842 if you choose "Direct", the BIOS won't be used, and if you 1843 choose "MMConfig", then PCI Express MMCONFIG will be used. 1844 If you choose "Any", the kernel will try MMCONFIG, then the 1845 direct access method and falls back to the BIOS if that doesn't 1846 work. If unsure, go with the default, which is "Any". 1847 1848config PCI_GOBIOS 1849 bool "BIOS" 1850 1851config PCI_GOMMCONFIG 1852 bool "MMConfig" 1853 1854config PCI_GODIRECT 1855 bool "Direct" 1856 1857config PCI_GOOLPC 1858 bool "OLPC" 1859 depends on OLPC 1860 1861config PCI_GOANY 1862 bool "Any" 1863 1864endchoice 1865 1866config PCI_BIOS 1867 def_bool y 1868 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 1869 1870# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 1871config PCI_DIRECT 1872 def_bool y 1873 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC)) 1874 1875config PCI_MMCONFIG 1876 def_bool y 1877 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 1878 1879config PCI_OLPC 1880 def_bool y 1881 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 1882 1883config PCI_DOMAINS 1884 def_bool y 1885 depends on PCI 1886 1887config PCI_MMCONFIG 1888 bool "Support mmconfig PCI config space access" 1889 depends on X86_64 && PCI && ACPI 1890 1891config DMAR 1892 bool "Support for DMA Remapping Devices (EXPERIMENTAL)" 1893 depends on PCI_MSI && ACPI && EXPERIMENTAL 1894 help 1895 DMA remapping (DMAR) devices support enables independent address 1896 translations for Direct Memory Access (DMA) from devices. 1897 These DMA remapping devices are reported via ACPI tables 1898 and include PCI device scope covered by these DMA 1899 remapping devices. 1900 1901config DMAR_DEFAULT_ON 1902 def_bool y 1903 prompt "Enable DMA Remapping Devices by default" 1904 depends on DMAR 1905 help 1906 Selecting this option will enable a DMAR device at boot time if 1907 one is found. If this option is not selected, DMAR support can 1908 be enabled by passing intel_iommu=on to the kernel. It is 1909 recommended you say N here while the DMAR code remains 1910 experimental. 1911 1912config DMAR_BROKEN_GFX_WA 1913 def_bool n 1914 prompt "Workaround broken graphics drivers (going away soon)" 1915 depends on DMAR && BROKEN 1916 ---help--- 1917 Current Graphics drivers tend to use physical address 1918 for DMA and avoid using DMA APIs. Setting this config 1919 option permits the IOMMU driver to set a unity map for 1920 all the OS-visible memory. Hence the driver can continue 1921 to use physical addresses for DMA, at least until this 1922 option is removed in the 2.6.32 kernel. 1923 1924config DMAR_FLOPPY_WA 1925 def_bool y 1926 depends on DMAR 1927 ---help--- 1928 Floppy disk drivers are known to bypass DMA API calls 1929 thereby failing to work when IOMMU is enabled. This 1930 workaround will setup a 1:1 mapping for the first 1931 16MiB to make floppy (an ISA device) work. 1932 1933config INTR_REMAP 1934 bool "Support for Interrupt Remapping (EXPERIMENTAL)" 1935 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL 1936 ---help--- 1937 Supports Interrupt remapping for IO-APIC and MSI devices. 1938 To use x2apic mode in the CPU's which support x2APIC enhancements or 1939 to support platforms with CPU's having > 8 bit APIC ID, say Y. 1940 1941source "drivers/pci/pcie/Kconfig" 1942 1943source "drivers/pci/Kconfig" 1944 1945# x86_64 have no ISA slots, but do have ISA-style DMA. 1946config ISA_DMA_API 1947 def_bool y 1948 1949if X86_32 1950 1951config ISA 1952 bool "ISA support" 1953 ---help--- 1954 Find out whether you have ISA slots on your motherboard. ISA is the 1955 name of a bus system, i.e. the way the CPU talks to the other stuff 1956 inside your box. Other bus systems are PCI, EISA, MicroChannel 1957 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 1958 newer boards don't support it. If you have ISA, say Y, otherwise N. 1959 1960config EISA 1961 bool "EISA support" 1962 depends on ISA 1963 ---help--- 1964 The Extended Industry Standard Architecture (EISA) bus was 1965 developed as an open alternative to the IBM MicroChannel bus. 1966 1967 The EISA bus provided some of the features of the IBM MicroChannel 1968 bus while maintaining backward compatibility with cards made for 1969 the older ISA bus. The EISA bus saw limited use between 1988 and 1970 1995 when it was made obsolete by the PCI bus. 1971 1972 Say Y here if you are building a kernel for an EISA-based machine. 1973 1974 Otherwise, say N. 1975 1976source "drivers/eisa/Kconfig" 1977 1978config MCA 1979 bool "MCA support" 1980 ---help--- 1981 MicroChannel Architecture is found in some IBM PS/2 machines and 1982 laptops. It is a bus system similar to PCI or ISA. See 1983 <file:Documentation/mca.txt> (and especially the web page given 1984 there) before attempting to build an MCA bus kernel. 1985 1986source "drivers/mca/Kconfig" 1987 1988config SCx200 1989 tristate "NatSemi SCx200 support" 1990 ---help--- 1991 This provides basic support for National Semiconductor's 1992 (now AMD's) Geode processors. The driver probes for the 1993 PCI-IDs of several on-chip devices, so its a good dependency 1994 for other scx200_* drivers. 1995 1996 If compiled as a module, the driver is named scx200. 1997 1998config SCx200HR_TIMER 1999 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2000 depends on SCx200 && GENERIC_TIME 2001 default y 2002 ---help--- 2003 This driver provides a clocksource built upon the on-chip 2004 27MHz high-resolution timer. Its also a workaround for 2005 NSC Geode SC-1100's buggy TSC, which loses time when the 2006 processor goes idle (as is done by the scheduler). The 2007 other workaround is idle=poll boot option. 2008 2009config GEODE_MFGPT_TIMER 2010 def_bool y 2011 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events" 2012 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS 2013 ---help--- 2014 This driver provides a clock event source based on the MFGPT 2015 timer(s) in the CS5535 and CS5536 companion chip for the geode. 2016 MFGPTs have a better resolution and max interval than the 2017 generic PIT, and are suitable for use as high-res timers. 2018 2019config OLPC 2020 bool "One Laptop Per Child support" 2021 default n 2022 ---help--- 2023 Add support for detecting the unique features of the OLPC 2024 XO hardware. 2025 2026endif # X86_32 2027 2028config K8_NB 2029 def_bool y 2030 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA))) 2031 2032source "drivers/pcmcia/Kconfig" 2033 2034source "drivers/pci/hotplug/Kconfig" 2035 2036endmenu 2037 2038 2039menu "Executable file formats / Emulations" 2040 2041source "fs/Kconfig.binfmt" 2042 2043config IA32_EMULATION 2044 bool "IA32 Emulation" 2045 depends on X86_64 2046 select COMPAT_BINFMT_ELF 2047 ---help--- 2048 Include code to run 32-bit programs under a 64-bit kernel. You should 2049 likely turn this on, unless you're 100% sure that you don't have any 2050 32-bit programs left. 2051 2052config IA32_AOUT 2053 tristate "IA32 a.out support" 2054 depends on IA32_EMULATION 2055 ---help--- 2056 Support old a.out binaries in the 32bit emulation. 2057 2058config COMPAT 2059 def_bool y 2060 depends on IA32_EMULATION 2061 2062config COMPAT_FOR_U64_ALIGNMENT 2063 def_bool COMPAT 2064 depends on X86_64 2065 2066config SYSVIPC_COMPAT 2067 def_bool y 2068 depends on COMPAT && SYSVIPC 2069 2070endmenu 2071 2072 2073config HAVE_ATOMIC_IOMAP 2074 def_bool y 2075 depends on X86_32 2076 2077source "net/Kconfig" 2078 2079source "drivers/Kconfig" 2080 2081source "drivers/firmware/Kconfig" 2082 2083source "fs/Kconfig" 2084 2085source "arch/x86/Kconfig.debug" 2086 2087source "security/Kconfig" 2088 2089source "crypto/Kconfig" 2090 2091source "arch/x86/kvm/Kconfig" 2092 2093source "lib/Kconfig" 2094