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 MMU 90 def_bool y 91 92config ZONE_DMA 93 def_bool y 94 95config SBUS 96 bool 97 98config GENERIC_ISA_DMA 99 def_bool y 100 101config GENERIC_IOMAP 102 def_bool y 103 104config GENERIC_BUG 105 def_bool y 106 depends on BUG 107 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 108 109config GENERIC_BUG_RELATIVE_POINTERS 110 bool 111 112config GENERIC_HWEIGHT 113 def_bool y 114 115config GENERIC_GPIO 116 bool 117 118config ARCH_MAY_HAVE_PC_FDC 119 def_bool y 120 121config RWSEM_GENERIC_SPINLOCK 122 def_bool !X86_XADD 123 124config RWSEM_XCHGADD_ALGORITHM 125 def_bool X86_XADD 126 127config ARCH_HAS_CPU_IDLE_WAIT 128 def_bool y 129 130config GENERIC_CALIBRATE_DELAY 131 def_bool y 132 133config GENERIC_TIME_VSYSCALL 134 bool 135 default X86_64 136 137config ARCH_HAS_CPU_RELAX 138 def_bool y 139 140config ARCH_HAS_DEFAULT_IDLE 141 def_bool y 142 143config ARCH_HAS_CACHE_LINE_SIZE 144 def_bool y 145 146config HAVE_SETUP_PER_CPU_AREA 147 def_bool y 148 149config NEED_PER_CPU_EMBED_FIRST_CHUNK 150 def_bool y 151 152config NEED_PER_CPU_PAGE_FIRST_CHUNK 153 def_bool y 154 155config HAVE_CPUMASK_OF_CPU_MAP 156 def_bool X86_64_SMP 157 158config ARCH_HIBERNATION_POSSIBLE 159 def_bool y 160 161config ARCH_SUSPEND_POSSIBLE 162 def_bool y 163 164config ZONE_DMA32 165 bool 166 default X86_64 167 168config ARCH_POPULATES_NODE_MAP 169 def_bool y 170 171config AUDIT_ARCH 172 bool 173 default X86_64 174 175config ARCH_SUPPORTS_OPTIMIZED_INLINING 176 def_bool y 177 178config ARCH_SUPPORTS_DEBUG_PAGEALLOC 179 def_bool y 180 181config HAVE_INTEL_TXT 182 def_bool y 183 depends on EXPERIMENTAL && DMAR && ACPI 184 185# Use the generic interrupt handling code in kernel/irq/: 186config GENERIC_HARDIRQS 187 bool 188 default y 189 190config GENERIC_HARDIRQS_NO__DO_IRQ 191 def_bool y 192 193config GENERIC_IRQ_PROBE 194 bool 195 default y 196 197config GENERIC_PENDING_IRQ 198 bool 199 depends on GENERIC_HARDIRQS && SMP 200 default y 201 202config USE_GENERIC_SMP_HELPERS 203 def_bool y 204 depends on SMP 205 206config X86_32_SMP 207 def_bool y 208 depends on X86_32 && SMP 209 210config X86_64_SMP 211 def_bool y 212 depends on X86_64 && SMP 213 214config X86_HT 215 bool 216 depends on SMP 217 default y 218 219config X86_TRAMPOLINE 220 bool 221 depends on SMP || (64BIT && ACPI_SLEEP) 222 default y 223 224config X86_32_LAZY_GS 225 def_bool y 226 depends on X86_32 && !CC_STACKPROTECTOR 227 228config KTIME_SCALAR 229 def_bool X86_32 230source "init/Kconfig" 231source "kernel/Kconfig.freezer" 232 233menu "Processor type and features" 234 235source "kernel/time/Kconfig" 236 237config SMP 238 bool "Symmetric multi-processing support" 239 ---help--- 240 This enables support for systems with more than one CPU. If you have 241 a system with only one CPU, like most personal computers, say N. If 242 you have a system with more than one CPU, say Y. 243 244 If you say N here, the kernel will run on single and multiprocessor 245 machines, but will use only one CPU of a multiprocessor machine. If 246 you say Y here, the kernel will run on many, but not all, 247 singleprocessor machines. On a singleprocessor machine, the kernel 248 will run faster if you say N here. 249 250 Note that if you say Y here and choose architecture "586" or 251 "Pentium" under "Processor family", the kernel will not work on 486 252 architectures. Similarly, multiprocessor kernels for the "PPro" 253 architecture may not work on all Pentium based boards. 254 255 People using multiprocessor machines who say Y here should also say 256 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 257 Management" code will be disabled if you say Y here. 258 259 See also <file:Documentation/i386/IO-APIC.txt>, 260 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 261 <http://www.tldp.org/docs.html#howto>. 262 263 If you don't know what to do here, say N. 264 265config X86_X2APIC 266 bool "Support x2apic" 267 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP 268 ---help--- 269 This enables x2apic support on CPUs that have this feature. 270 271 This allows 32-bit apic IDs (so it can support very large systems), 272 and accesses the local apic via MSRs not via mmio. 273 274 If you don't know what to do here, say N. 275 276config SPARSE_IRQ 277 bool "Support sparse irq numbering" 278 depends on PCI_MSI || HT_IRQ 279 ---help--- 280 This enables support for sparse irqs. This is useful for distro 281 kernels that want to define a high CONFIG_NR_CPUS value but still 282 want to have low kernel memory footprint on smaller machines. 283 284 ( Sparse IRQs can also be beneficial on NUMA boxes, as they spread 285 out the irq_desc[] array in a more NUMA-friendly way. ) 286 287 If you don't know what to do here, say N. 288 289config NUMA_IRQ_DESC 290 def_bool y 291 depends on SPARSE_IRQ && NUMA 292 293config X86_MPPARSE 294 bool "Enable MPS table" if ACPI 295 default y 296 depends on X86_LOCAL_APIC 297 ---help--- 298 For old smp systems that do not have proper acpi support. Newer systems 299 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 300 301config X86_BIGSMP 302 bool "Support for big SMP systems with more than 8 CPUs" 303 depends on X86_32 && SMP 304 ---help--- 305 This option is needed for the systems that have more than 8 CPUs 306 307if X86_32 308config X86_EXTENDED_PLATFORM 309 bool "Support for extended (non-PC) x86 platforms" 310 default y 311 ---help--- 312 If you disable this option then the kernel will only support 313 standard PC platforms. (which covers the vast majority of 314 systems out there.) 315 316 If you enable this option then you'll be able to select support 317 for the following (non-PC) 32 bit x86 platforms: 318 AMD Elan 319 NUMAQ (IBM/Sequent) 320 RDC R-321x SoC 321 SGI 320/540 (Visual Workstation) 322 Summit/EXA (IBM x440) 323 Unisys ES7000 IA32 series 324 Moorestown MID devices 325 326 If you have one of these systems, or if you want to build a 327 generic distribution kernel, say Y here - otherwise say N. 328endif 329 330if X86_64 331config X86_EXTENDED_PLATFORM 332 bool "Support for extended (non-PC) x86 platforms" 333 default y 334 ---help--- 335 If you disable this option then the kernel will only support 336 standard PC platforms. (which covers the vast majority of 337 systems out there.) 338 339 If you enable this option then you'll be able to select support 340 for the following (non-PC) 64 bit x86 platforms: 341 ScaleMP vSMP 342 SGI Ultraviolet 343 344 If you have one of these systems, or if you want to build a 345 generic distribution kernel, say Y here - otherwise say N. 346endif 347# This is an alphabetically sorted list of 64 bit extended platforms 348# Please maintain the alphabetic order if and when there are additions 349 350config X86_VSMP 351 bool "ScaleMP vSMP" 352 select PARAVIRT 353 depends on X86_64 && PCI 354 depends on X86_EXTENDED_PLATFORM 355 ---help--- 356 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 357 supposed to run on these EM64T-based machines. Only choose this option 358 if you have one of these machines. 359 360config X86_UV 361 bool "SGI Ultraviolet" 362 depends on X86_64 363 depends on X86_EXTENDED_PLATFORM 364 depends on NUMA 365 depends on X86_X2APIC 366 ---help--- 367 This option is needed in order to support SGI Ultraviolet systems. 368 If you don't have one of these, you should say N here. 369 370# Following is an alphabetically sorted list of 32 bit extended platforms 371# Please maintain the alphabetic order if and when there are additions 372 373config X86_ELAN 374 bool "AMD Elan" 375 depends on X86_32 376 depends on X86_EXTENDED_PLATFORM 377 ---help--- 378 Select this for an AMD Elan processor. 379 380 Do not use this option for K6/Athlon/Opteron processors! 381 382 If unsure, choose "PC-compatible" instead. 383 384config X86_MRST 385 bool "Moorestown MID platform" 386 depends on X86_32 387 depends on X86_EXTENDED_PLATFORM 388 ---help--- 389 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin 390 Internet Device(MID) platform. Moorestown consists of two chips: 391 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH. 392 Unlike standard x86 PCs, Moorestown does not have many legacy devices 393 nor standard legacy replacement devices/features. e.g. Moorestown does 394 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports. 395 396config X86_RDC321X 397 bool "RDC R-321x SoC" 398 depends on X86_32 399 depends on X86_EXTENDED_PLATFORM 400 select M486 401 select X86_REBOOTFIXUPS 402 ---help--- 403 This option is needed for RDC R-321x system-on-chip, also known 404 as R-8610-(G). 405 If you don't have one of these chips, you should say N here. 406 407config X86_32_NON_STANDARD 408 bool "Support non-standard 32-bit SMP architectures" 409 depends on X86_32 && SMP 410 depends on X86_EXTENDED_PLATFORM 411 ---help--- 412 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default 413 subarchitectures. It is intended for a generic binary kernel. 414 if you select them all, kernel will probe it one by one. and will 415 fallback to default. 416 417# Alphabetically sorted list of Non standard 32 bit platforms 418 419config X86_NUMAQ 420 bool "NUMAQ (IBM/Sequent)" 421 depends on X86_32_NON_STANDARD 422 select NUMA 423 select X86_MPPARSE 424 ---help--- 425 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent) 426 NUMA multiquad box. This changes the way that processors are 427 bootstrapped, and uses Clustered Logical APIC addressing mode instead 428 of Flat Logical. You will need a new lynxer.elf file to flash your 429 firmware with - send email to <Martin.Bligh@us.ibm.com>. 430 431config X86_SUPPORTS_MEMORY_FAILURE 432 bool 433 # MCE code calls memory_failure(): 434 depends on X86_MCE 435 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 436 depends on !X86_NUMAQ 437 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 438 depends on X86_64 || !SPARSEMEM 439 select ARCH_SUPPORTS_MEMORY_FAILURE 440 default y 441 442config X86_VISWS 443 bool "SGI 320/540 (Visual Workstation)" 444 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT 445 depends on X86_32_NON_STANDARD 446 ---help--- 447 The SGI Visual Workstation series is an IA32-based workstation 448 based on SGI systems chips with some legacy PC hardware attached. 449 450 Say Y here to create a kernel to run on the SGI 320 or 540. 451 452 A kernel compiled for the Visual Workstation will run on general 453 PCs as well. See <file:Documentation/sgi-visws.txt> for details. 454 455config X86_SUMMIT 456 bool "Summit/EXA (IBM x440)" 457 depends on X86_32_NON_STANDARD 458 ---help--- 459 This option is needed for IBM systems that use the Summit/EXA chipset. 460 In particular, it is needed for the x440. 461 462config X86_ES7000 463 bool "Unisys ES7000 IA32 series" 464 depends on X86_32_NON_STANDARD && X86_BIGSMP 465 ---help--- 466 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 467 supposed to run on an IA32-based Unisys ES7000 system. 468 469config SCHED_OMIT_FRAME_POINTER 470 def_bool y 471 prompt "Single-depth WCHAN output" 472 depends on X86 473 ---help--- 474 Calculate simpler /proc/<PID>/wchan values. If this option 475 is disabled then wchan values will recurse back to the 476 caller function. This provides more accurate wchan values, 477 at the expense of slightly more scheduling overhead. 478 479 If in doubt, say "Y". 480 481menuconfig PARAVIRT_GUEST 482 bool "Paravirtualized guest support" 483 ---help--- 484 Say Y here to get to see options related to running Linux under 485 various hypervisors. This option alone does not add any kernel code. 486 487 If you say N, all options in this submenu will be skipped and disabled. 488 489if PARAVIRT_GUEST 490 491source "arch/x86/xen/Kconfig" 492 493config VMI 494 bool "VMI Guest support" 495 select PARAVIRT 496 depends on X86_32 497 ---help--- 498 VMI provides a paravirtualized interface to the VMware ESX server 499 (it could be used by other hypervisors in theory too, but is not 500 at the moment), by linking the kernel to a GPL-ed ROM module 501 provided by the hypervisor. 502 503config KVM_CLOCK 504 bool "KVM paravirtualized clock" 505 select PARAVIRT 506 select PARAVIRT_CLOCK 507 ---help--- 508 Turning on this option will allow you to run a paravirtualized clock 509 when running over the KVM hypervisor. Instead of relying on a PIT 510 (or probably other) emulation by the underlying device model, the host 511 provides the guest with timing infrastructure such as time of day, and 512 system time 513 514config KVM_GUEST 515 bool "KVM Guest support" 516 select PARAVIRT 517 ---help--- 518 This option enables various optimizations for running under the KVM 519 hypervisor. 520 521source "arch/x86/lguest/Kconfig" 522 523config PARAVIRT 524 bool "Enable paravirtualization code" 525 ---help--- 526 This changes the kernel so it can modify itself when it is run 527 under a hypervisor, potentially improving performance significantly 528 over full virtualization. However, when run without a hypervisor 529 the kernel is theoretically slower and slightly larger. 530 531config PARAVIRT_SPINLOCKS 532 bool "Paravirtualization layer for spinlocks" 533 depends on PARAVIRT && SMP && EXPERIMENTAL 534 ---help--- 535 Paravirtualized spinlocks allow a pvops backend to replace the 536 spinlock implementation with something virtualization-friendly 537 (for example, block the virtual CPU rather than spinning). 538 539 Unfortunately the downside is an up to 5% performance hit on 540 native kernels, with various workloads. 541 542 If you are unsure how to answer this question, answer N. 543 544config PARAVIRT_CLOCK 545 bool 546 default n 547 548endif 549 550config PARAVIRT_DEBUG 551 bool "paravirt-ops debugging" 552 depends on PARAVIRT && DEBUG_KERNEL 553 ---help--- 554 Enable to debug paravirt_ops internals. Specifically, BUG if 555 a paravirt_op is missing when it is called. 556 557config MEMTEST 558 bool "Memtest" 559 ---help--- 560 This option adds a kernel parameter 'memtest', which allows memtest 561 to be set. 562 memtest=0, mean disabled; -- default 563 memtest=1, mean do 1 test pattern; 564 ... 565 memtest=4, mean do 4 test patterns. 566 If you are unsure how to answer this question, answer N. 567 568config X86_SUMMIT_NUMA 569 def_bool y 570 depends on X86_32 && NUMA && X86_32_NON_STANDARD 571 572config X86_CYCLONE_TIMER 573 def_bool y 574 depends on X86_32_NON_STANDARD 575 576source "arch/x86/Kconfig.cpu" 577 578config HPET_TIMER 579 def_bool X86_64 580 prompt "HPET Timer Support" if X86_32 581 ---help--- 582 Use the IA-PC HPET (High Precision Event Timer) to manage 583 time in preference to the PIT and RTC, if a HPET is 584 present. 585 HPET is the next generation timer replacing legacy 8254s. 586 The HPET provides a stable time base on SMP 587 systems, unlike the TSC, but it is more expensive to access, 588 as it is off-chip. You can find the HPET spec at 589 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 590 591 You can safely choose Y here. However, HPET will only be 592 activated if the platform and the BIOS support this feature. 593 Otherwise the 8254 will be used for timing services. 594 595 Choose N to continue using the legacy 8254 timer. 596 597config HPET_EMULATE_RTC 598 def_bool y 599 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 600 601# Mark as embedded because too many people got it wrong. 602# The code disables itself when not needed. 603config DMI 604 default y 605 bool "Enable DMI scanning" if EMBEDDED 606 ---help--- 607 Enabled scanning of DMI to identify machine quirks. Say Y 608 here unless you have verified that your setup is not 609 affected by entries in the DMI blacklist. Required by PNP 610 BIOS code. 611 612config GART_IOMMU 613 bool "GART IOMMU support" if EMBEDDED 614 default y 615 select SWIOTLB 616 depends on X86_64 && PCI 617 ---help--- 618 Support for full DMA access of devices with 32bit memory access only 619 on systems with more than 3GB. This is usually needed for USB, 620 sound, many IDE/SATA chipsets and some other devices. 621 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART 622 based hardware IOMMU and a software bounce buffer based IOMMU used 623 on Intel systems and as fallback. 624 The code is only active when needed (enough memory and limited 625 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified 626 too. 627 628config CALGARY_IOMMU 629 bool "IBM Calgary IOMMU support" 630 select SWIOTLB 631 depends on X86_64 && PCI && EXPERIMENTAL 632 ---help--- 633 Support for hardware IOMMUs in IBM's xSeries x366 and x460 634 systems. Needed to run systems with more than 3GB of memory 635 properly with 32-bit PCI devices that do not support DAC 636 (Double Address Cycle). Calgary also supports bus level 637 isolation, where all DMAs pass through the IOMMU. This 638 prevents them from going anywhere except their intended 639 destination. This catches hard-to-find kernel bugs and 640 mis-behaving drivers and devices that do not use the DMA-API 641 properly to set up their DMA buffers. The IOMMU can be 642 turned off at boot time with the iommu=off parameter. 643 Normally the kernel will make the right choice by itself. 644 If unsure, say Y. 645 646config CALGARY_IOMMU_ENABLED_BY_DEFAULT 647 def_bool y 648 prompt "Should Calgary be enabled by default?" 649 depends on CALGARY_IOMMU 650 ---help--- 651 Should Calgary be enabled by default? if you choose 'y', Calgary 652 will be used (if it exists). If you choose 'n', Calgary will not be 653 used even if it exists. If you choose 'n' and would like to use 654 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 655 If unsure, say Y. 656 657config AMD_IOMMU 658 bool "AMD IOMMU support" 659 select SWIOTLB 660 select PCI_MSI 661 depends on X86_64 && PCI && ACPI 662 ---help--- 663 With this option you can enable support for AMD IOMMU hardware in 664 your system. An IOMMU is a hardware component which provides 665 remapping of DMA memory accesses from devices. With an AMD IOMMU you 666 can isolate the the DMA memory of different devices and protect the 667 system from misbehaving device drivers or hardware. 668 669 You can find out if your system has an AMD IOMMU if you look into 670 your BIOS for an option to enable it or if you have an IVRS ACPI 671 table. 672 673config AMD_IOMMU_STATS 674 bool "Export AMD IOMMU statistics to debugfs" 675 depends on AMD_IOMMU 676 select DEBUG_FS 677 ---help--- 678 This option enables code in the AMD IOMMU driver to collect various 679 statistics about whats happening in the driver and exports that 680 information to userspace via debugfs. 681 If unsure, say N. 682 683# need this always selected by IOMMU for the VIA workaround 684config SWIOTLB 685 def_bool y if X86_64 686 ---help--- 687 Support for software bounce buffers used on x86-64 systems 688 which don't have a hardware IOMMU (e.g. the current generation 689 of Intel's x86-64 CPUs). Using this PCI devices which can only 690 access 32-bits of memory can be used on systems with more than 691 3 GB of memory. If unsure, say Y. 692 693config IOMMU_HELPER 694 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU) 695 696config IOMMU_API 697 def_bool (AMD_IOMMU || DMAR) 698 699config MAXSMP 700 bool "Configure Maximum number of SMP Processors and NUMA Nodes" 701 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL 702 select CPUMASK_OFFSTACK 703 default n 704 ---help--- 705 Configure maximum number of CPUS and NUMA Nodes for this architecture. 706 If unsure, say N. 707 708config NR_CPUS 709 int "Maximum number of CPUs" if SMP && !MAXSMP 710 range 2 8 if SMP && X86_32 && !X86_BIGSMP 711 range 2 512 if SMP && !MAXSMP 712 default "1" if !SMP 713 default "4096" if MAXSMP 714 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000) 715 default "8" if SMP 716 ---help--- 717 This allows you to specify the maximum number of CPUs which this 718 kernel will support. The maximum supported value is 512 and the 719 minimum value which makes sense is 2. 720 721 This is purely to save memory - each supported CPU adds 722 approximately eight kilobytes to the kernel image. 723 724config SCHED_SMT 725 bool "SMT (Hyperthreading) scheduler support" 726 depends on X86_HT 727 ---help--- 728 SMT scheduler support improves the CPU scheduler's decision making 729 when dealing with Intel Pentium 4 chips with HyperThreading at a 730 cost of slightly increased overhead in some places. If unsure say 731 N here. 732 733config SCHED_MC 734 def_bool y 735 prompt "Multi-core scheduler support" 736 depends on X86_HT 737 ---help--- 738 Multi-core scheduler support improves the CPU scheduler's decision 739 making when dealing with multi-core CPU chips at a cost of slightly 740 increased overhead in some places. If unsure say N here. 741 742source "kernel/Kconfig.preempt" 743 744config X86_UP_APIC 745 bool "Local APIC support on uniprocessors" 746 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 747 ---help--- 748 A local APIC (Advanced Programmable Interrupt Controller) is an 749 integrated interrupt controller in the CPU. If you have a single-CPU 750 system which has a processor with a local APIC, you can say Y here to 751 enable and use it. If you say Y here even though your machine doesn't 752 have a local APIC, then the kernel will still run with no slowdown at 753 all. The local APIC supports CPU-generated self-interrupts (timer, 754 performance counters), and the NMI watchdog which detects hard 755 lockups. 756 757config X86_UP_IOAPIC 758 bool "IO-APIC support on uniprocessors" 759 depends on X86_UP_APIC 760 ---help--- 761 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 762 SMP-capable replacement for PC-style interrupt controllers. Most 763 SMP systems and many recent uniprocessor systems have one. 764 765 If you have a single-CPU system with an IO-APIC, you can say Y here 766 to use it. If you say Y here even though your machine doesn't have 767 an IO-APIC, then the kernel will still run with no slowdown at all. 768 769config X86_LOCAL_APIC 770 def_bool y 771 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC 772 773config X86_IO_APIC 774 def_bool y 775 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC 776 777config X86_VISWS_APIC 778 def_bool y 779 depends on X86_32 && X86_VISWS 780 781config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 782 bool "Reroute for broken boot IRQs" 783 default n 784 depends on X86_IO_APIC 785 ---help--- 786 This option enables a workaround that fixes a source of 787 spurious interrupts. This is recommended when threaded 788 interrupt handling is used on systems where the generation of 789 superfluous "boot interrupts" cannot be disabled. 790 791 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 792 entry in the chipset's IO-APIC is masked (as, e.g. the RT 793 kernel does during interrupt handling). On chipsets where this 794 boot IRQ generation cannot be disabled, this workaround keeps 795 the original IRQ line masked so that only the equivalent "boot 796 IRQ" is delivered to the CPUs. The workaround also tells the 797 kernel to set up the IRQ handler on the boot IRQ line. In this 798 way only one interrupt is delivered to the kernel. Otherwise 799 the spurious second interrupt may cause the kernel to bring 800 down (vital) interrupt lines. 801 802 Only affects "broken" chipsets. Interrupt sharing may be 803 increased on these systems. 804 805config X86_MCE 806 bool "Machine Check / overheating reporting" 807 ---help--- 808 Machine Check support allows the processor to notify the 809 kernel if it detects a problem (e.g. overheating, data corruption). 810 The action the kernel takes depends on the severity of the problem, 811 ranging from warning messages to halting the machine. 812 813config X86_MCE_INTEL 814 def_bool y 815 prompt "Intel MCE features" 816 depends on X86_MCE && X86_LOCAL_APIC 817 ---help--- 818 Additional support for intel specific MCE features such as 819 the thermal monitor. 820 821config X86_MCE_AMD 822 def_bool y 823 prompt "AMD MCE features" 824 depends on X86_MCE && X86_LOCAL_APIC 825 ---help--- 826 Additional support for AMD specific MCE features such as 827 the DRAM Error Threshold. 828 829config X86_ANCIENT_MCE 830 def_bool n 831 depends on X86_32 && X86_MCE 832 prompt "Support for old Pentium 5 / WinChip machine checks" 833 ---help--- 834 Include support for machine check handling on old Pentium 5 or WinChip 835 systems. These typically need to be enabled explicitely on the command 836 line. 837 838config X86_MCE_THRESHOLD 839 depends on X86_MCE_AMD || X86_MCE_INTEL 840 bool 841 default y 842 843config X86_MCE_INJECT 844 depends on X86_MCE 845 tristate "Machine check injector support" 846 ---help--- 847 Provide support for injecting machine checks for testing purposes. 848 If you don't know what a machine check is and you don't do kernel 849 QA it is safe to say n. 850 851config X86_THERMAL_VECTOR 852 def_bool y 853 depends on X86_MCE_INTEL 854 855config VM86 856 bool "Enable VM86 support" if EMBEDDED 857 default y 858 depends on X86_32 859 ---help--- 860 This option is required by programs like DOSEMU to run 16-bit legacy 861 code on X86 processors. It also may be needed by software like 862 XFree86 to initialize some video cards via BIOS. Disabling this 863 option saves about 6k. 864 865config TOSHIBA 866 tristate "Toshiba Laptop support" 867 depends on X86_32 868 ---help--- 869 This adds a driver to safely access the System Management Mode of 870 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 871 not work on models with a Phoenix BIOS. The System Management Mode 872 is used to set the BIOS and power saving options on Toshiba portables. 873 874 For information on utilities to make use of this driver see the 875 Toshiba Linux utilities web site at: 876 <http://www.buzzard.org.uk/toshiba/>. 877 878 Say Y if you intend to run this kernel on a Toshiba portable. 879 Say N otherwise. 880 881config I8K 882 tristate "Dell laptop support" 883 ---help--- 884 This adds a driver to safely access the System Management Mode 885 of the CPU on the Dell Inspiron 8000. The System Management Mode 886 is used to read cpu temperature and cooling fan status and to 887 control the fans on the I8K portables. 888 889 This driver has been tested only on the Inspiron 8000 but it may 890 also work with other Dell laptops. You can force loading on other 891 models by passing the parameter `force=1' to the module. Use at 892 your own risk. 893 894 For information on utilities to make use of this driver see the 895 I8K Linux utilities web site at: 896 <http://people.debian.org/~dz/i8k/> 897 898 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 899 Say N otherwise. 900 901config X86_REBOOTFIXUPS 902 bool "Enable X86 board specific fixups for reboot" 903 depends on X86_32 904 ---help--- 905 This enables chipset and/or board specific fixups to be done 906 in order to get reboot to work correctly. This is only needed on 907 some combinations of hardware and BIOS. The symptom, for which 908 this config is intended, is when reboot ends with a stalled/hung 909 system. 910 911 Currently, the only fixup is for the Geode machines using 912 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 913 914 Say Y if you want to enable the fixup. Currently, it's safe to 915 enable this option even if you don't need it. 916 Say N otherwise. 917 918config MICROCODE 919 tristate "/dev/cpu/microcode - microcode support" 920 select FW_LOADER 921 ---help--- 922 If you say Y here, you will be able to update the microcode on 923 certain Intel and AMD processors. The Intel support is for the 924 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, 925 Pentium 4, Xeon etc. The AMD support is for family 0x10 and 926 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra. 927 You will obviously need the actual microcode binary data itself 928 which is not shipped with the Linux kernel. 929 930 This option selects the general module only, you need to select 931 at least one vendor specific module as well. 932 933 To compile this driver as a module, choose M here: the 934 module will be called microcode. 935 936config MICROCODE_INTEL 937 bool "Intel microcode patch loading support" 938 depends on MICROCODE 939 default MICROCODE 940 select FW_LOADER 941 ---help--- 942 This options enables microcode patch loading support for Intel 943 processors. 944 945 For latest news and information on obtaining all the required 946 Intel ingredients for this driver, check: 947 <http://www.urbanmyth.org/microcode/>. 948 949config MICROCODE_AMD 950 bool "AMD microcode patch loading support" 951 depends on MICROCODE 952 select FW_LOADER 953 ---help--- 954 If you select this option, microcode patch loading support for AMD 955 processors will be enabled. 956 957config MICROCODE_OLD_INTERFACE 958 def_bool y 959 depends on MICROCODE 960 961config X86_MSR 962 tristate "/dev/cpu/*/msr - Model-specific register support" 963 ---help--- 964 This device gives privileged processes access to the x86 965 Model-Specific Registers (MSRs). It is a character device with 966 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 967 MSR accesses are directed to a specific CPU on multi-processor 968 systems. 969 970config X86_CPUID 971 tristate "/dev/cpu/*/cpuid - CPU information support" 972 ---help--- 973 This device gives processes access to the x86 CPUID instruction to 974 be executed on a specific processor. It is a character device 975 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 976 /dev/cpu/31/cpuid. 977 978config X86_CPU_DEBUG 979 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support" 980 ---help--- 981 If you select this option, this will provide various x86 CPUs 982 information through debugfs. 983 984choice 985 prompt "High Memory Support" 986 default HIGHMEM4G if !X86_NUMAQ 987 default HIGHMEM64G if X86_NUMAQ 988 depends on X86_32 989 990config NOHIGHMEM 991 bool "off" 992 depends on !X86_NUMAQ 993 ---help--- 994 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 995 However, the address space of 32-bit x86 processors is only 4 996 Gigabytes large. That means that, if you have a large amount of 997 physical memory, not all of it can be "permanently mapped" by the 998 kernel. The physical memory that's not permanently mapped is called 999 "high memory". 1000 1001 If you are compiling a kernel which will never run on a machine with 1002 more than 1 Gigabyte total physical RAM, answer "off" here (default 1003 choice and suitable for most users). This will result in a "3GB/1GB" 1004 split: 3GB are mapped so that each process sees a 3GB virtual memory 1005 space and the remaining part of the 4GB virtual memory space is used 1006 by the kernel to permanently map as much physical memory as 1007 possible. 1008 1009 If the machine has between 1 and 4 Gigabytes physical RAM, then 1010 answer "4GB" here. 1011 1012 If more than 4 Gigabytes is used then answer "64GB" here. This 1013 selection turns Intel PAE (Physical Address Extension) mode on. 1014 PAE implements 3-level paging on IA32 processors. PAE is fully 1015 supported by Linux, PAE mode is implemented on all recent Intel 1016 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1017 then the kernel will not boot on CPUs that don't support PAE! 1018 1019 The actual amount of total physical memory will either be 1020 auto detected or can be forced by using a kernel command line option 1021 such as "mem=256M". (Try "man bootparam" or see the documentation of 1022 your boot loader (lilo or loadlin) about how to pass options to the 1023 kernel at boot time.) 1024 1025 If unsure, say "off". 1026 1027config HIGHMEM4G 1028 bool "4GB" 1029 depends on !X86_NUMAQ 1030 ---help--- 1031 Select this if you have a 32-bit processor and between 1 and 4 1032 gigabytes of physical RAM. 1033 1034config HIGHMEM64G 1035 bool "64GB" 1036 depends on !M386 && !M486 1037 select X86_PAE 1038 ---help--- 1039 Select this if you have a 32-bit processor and more than 4 1040 gigabytes of physical RAM. 1041 1042endchoice 1043 1044choice 1045 depends on EXPERIMENTAL 1046 prompt "Memory split" if EMBEDDED 1047 default VMSPLIT_3G 1048 depends on X86_32 1049 ---help--- 1050 Select the desired split between kernel and user memory. 1051 1052 If the address range available to the kernel is less than the 1053 physical memory installed, the remaining memory will be available 1054 as "high memory". Accessing high memory is a little more costly 1055 than low memory, as it needs to be mapped into the kernel first. 1056 Note that increasing the kernel address space limits the range 1057 available to user programs, making the address space there 1058 tighter. Selecting anything other than the default 3G/1G split 1059 will also likely make your kernel incompatible with binary-only 1060 kernel modules. 1061 1062 If you are not absolutely sure what you are doing, leave this 1063 option alone! 1064 1065 config VMSPLIT_3G 1066 bool "3G/1G user/kernel split" 1067 config VMSPLIT_3G_OPT 1068 depends on !X86_PAE 1069 bool "3G/1G user/kernel split (for full 1G low memory)" 1070 config VMSPLIT_2G 1071 bool "2G/2G user/kernel split" 1072 config VMSPLIT_2G_OPT 1073 depends on !X86_PAE 1074 bool "2G/2G user/kernel split (for full 2G low memory)" 1075 config VMSPLIT_1G 1076 bool "1G/3G user/kernel split" 1077endchoice 1078 1079config PAGE_OFFSET 1080 hex 1081 default 0xB0000000 if VMSPLIT_3G_OPT 1082 default 0x80000000 if VMSPLIT_2G 1083 default 0x78000000 if VMSPLIT_2G_OPT 1084 default 0x40000000 if VMSPLIT_1G 1085 default 0xC0000000 1086 depends on X86_32 1087 1088config HIGHMEM 1089 def_bool y 1090 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1091 1092config X86_PAE 1093 bool "PAE (Physical Address Extension) Support" 1094 depends on X86_32 && !HIGHMEM4G 1095 ---help--- 1096 PAE is required for NX support, and furthermore enables 1097 larger swapspace support for non-overcommit purposes. It 1098 has the cost of more pagetable lookup overhead, and also 1099 consumes more pagetable space per process. 1100 1101config ARCH_PHYS_ADDR_T_64BIT 1102 def_bool X86_64 || X86_PAE 1103 1104config DIRECT_GBPAGES 1105 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED 1106 default y 1107 depends on X86_64 1108 ---help--- 1109 Allow the kernel linear mapping to use 1GB pages on CPUs that 1110 support it. This can improve the kernel's performance a tiny bit by 1111 reducing TLB pressure. If in doubt, say "Y". 1112 1113# Common NUMA Features 1114config NUMA 1115 bool "Numa Memory Allocation and Scheduler Support" 1116 depends on SMP 1117 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL) 1118 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP) 1119 ---help--- 1120 Enable NUMA (Non Uniform Memory Access) support. 1121 1122 The kernel will try to allocate memory used by a CPU on the 1123 local memory controller of the CPU and add some more 1124 NUMA awareness to the kernel. 1125 1126 For 64-bit this is recommended if the system is Intel Core i7 1127 (or later), AMD Opteron, or EM64T NUMA. 1128 1129 For 32-bit this is only needed on (rare) 32-bit-only platforms 1130 that support NUMA topologies, such as NUMAQ / Summit, or if you 1131 boot a 32-bit kernel on a 64-bit NUMA platform. 1132 1133 Otherwise, you should say N. 1134 1135comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 1136 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI) 1137 1138config K8_NUMA 1139 def_bool y 1140 prompt "Old style AMD Opteron NUMA detection" 1141 depends on X86_64 && NUMA && PCI 1142 ---help--- 1143 Enable K8 NUMA node topology detection. You should say Y here if 1144 you have a multi processor AMD K8 system. This uses an old 1145 method to read the NUMA configuration directly from the builtin 1146 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA 1147 instead, which also takes priority if both are compiled in. 1148 1149config X86_64_ACPI_NUMA 1150 def_bool y 1151 prompt "ACPI NUMA detection" 1152 depends on X86_64 && NUMA && ACPI && PCI 1153 select ACPI_NUMA 1154 ---help--- 1155 Enable ACPI SRAT based node topology detection. 1156 1157# Some NUMA nodes have memory ranges that span 1158# other nodes. Even though a pfn is valid and 1159# between a node's start and end pfns, it may not 1160# reside on that node. See memmap_init_zone() 1161# for details. 1162config NODES_SPAN_OTHER_NODES 1163 def_bool y 1164 depends on X86_64_ACPI_NUMA 1165 1166config NUMA_EMU 1167 bool "NUMA emulation" 1168 depends on X86_64 && NUMA 1169 ---help--- 1170 Enable NUMA emulation. A flat machine will be split 1171 into virtual nodes when booted with "numa=fake=N", where N is the 1172 number of nodes. This is only useful for debugging. 1173 1174config NODES_SHIFT 1175 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1176 range 1 9 1177 default "9" if MAXSMP 1178 default "6" if X86_64 1179 default "4" if X86_NUMAQ 1180 default "3" 1181 depends on NEED_MULTIPLE_NODES 1182 ---help--- 1183 Specify the maximum number of NUMA Nodes available on the target 1184 system. Increases memory reserved to accommodate various tables. 1185 1186config HAVE_ARCH_BOOTMEM 1187 def_bool y 1188 depends on X86_32 && NUMA 1189 1190config ARCH_HAVE_MEMORY_PRESENT 1191 def_bool y 1192 depends on X86_32 && DISCONTIGMEM 1193 1194config NEED_NODE_MEMMAP_SIZE 1195 def_bool y 1196 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1197 1198config HAVE_ARCH_ALLOC_REMAP 1199 def_bool y 1200 depends on X86_32 && NUMA 1201 1202config ARCH_FLATMEM_ENABLE 1203 def_bool y 1204 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA 1205 1206config ARCH_DISCONTIGMEM_ENABLE 1207 def_bool y 1208 depends on NUMA && X86_32 1209 1210config ARCH_DISCONTIGMEM_DEFAULT 1211 def_bool y 1212 depends on NUMA && X86_32 1213 1214config ARCH_PROC_KCORE_TEXT 1215 def_bool y 1216 depends on X86_64 && PROC_KCORE 1217 1218config ARCH_SPARSEMEM_DEFAULT 1219 def_bool y 1220 depends on X86_64 1221 1222config ARCH_SPARSEMEM_ENABLE 1223 def_bool y 1224 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD 1225 select SPARSEMEM_STATIC if X86_32 1226 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1227 1228config ARCH_SELECT_MEMORY_MODEL 1229 def_bool y 1230 depends on ARCH_SPARSEMEM_ENABLE 1231 1232config ARCH_MEMORY_PROBE 1233 def_bool X86_64 1234 depends on MEMORY_HOTPLUG 1235 1236source "mm/Kconfig" 1237 1238config HIGHPTE 1239 bool "Allocate 3rd-level pagetables from highmem" 1240 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G) 1241 ---help--- 1242 The VM uses one page table entry for each page of physical memory. 1243 For systems with a lot of RAM, this can be wasteful of precious 1244 low memory. Setting this option will put user-space page table 1245 entries in high memory. 1246 1247config X86_CHECK_BIOS_CORRUPTION 1248 bool "Check for low memory corruption" 1249 ---help--- 1250 Periodically check for memory corruption in low memory, which 1251 is suspected to be caused by BIOS. Even when enabled in the 1252 configuration, it is disabled at runtime. Enable it by 1253 setting "memory_corruption_check=1" on the kernel command 1254 line. By default it scans the low 64k of memory every 60 1255 seconds; see the memory_corruption_check_size and 1256 memory_corruption_check_period parameters in 1257 Documentation/kernel-parameters.txt to adjust this. 1258 1259 When enabled with the default parameters, this option has 1260 almost no overhead, as it reserves a relatively small amount 1261 of memory and scans it infrequently. It both detects corruption 1262 and prevents it from affecting the running system. 1263 1264 It is, however, intended as a diagnostic tool; if repeatable 1265 BIOS-originated corruption always affects the same memory, 1266 you can use memmap= to prevent the kernel from using that 1267 memory. 1268 1269config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1270 bool "Set the default setting of memory_corruption_check" 1271 depends on X86_CHECK_BIOS_CORRUPTION 1272 default y 1273 ---help--- 1274 Set whether the default state of memory_corruption_check is 1275 on or off. 1276 1277config X86_RESERVE_LOW_64K 1278 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen" 1279 default y 1280 ---help--- 1281 Reserve the first 64K of physical RAM on BIOSes that are known 1282 to potentially corrupt that memory range. A numbers of BIOSes are 1283 known to utilize this area during suspend/resume, so it must not 1284 be used by the kernel. 1285 1286 Set this to N if you are absolutely sure that you trust the BIOS 1287 to get all its memory reservations and usages right. 1288 1289 If you have doubts about the BIOS (e.g. suspend/resume does not 1290 work or there's kernel crashes after certain hardware hotplug 1291 events) and it's not AMI or Phoenix, then you might want to enable 1292 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical 1293 corruption patterns. 1294 1295 Say Y if unsure. 1296 1297config MATH_EMULATION 1298 bool 1299 prompt "Math emulation" if X86_32 1300 ---help--- 1301 Linux can emulate a math coprocessor (used for floating point 1302 operations) if you don't have one. 486DX and Pentium processors have 1303 a math coprocessor built in, 486SX and 386 do not, unless you added 1304 a 487DX or 387, respectively. (The messages during boot time can 1305 give you some hints here ["man dmesg"].) Everyone needs either a 1306 coprocessor or this emulation. 1307 1308 If you don't have a math coprocessor, you need to say Y here; if you 1309 say Y here even though you have a coprocessor, the coprocessor will 1310 be used nevertheless. (This behavior can be changed with the kernel 1311 command line option "no387", which comes handy if your coprocessor 1312 is broken. Try "man bootparam" or see the documentation of your boot 1313 loader (lilo or loadlin) about how to pass options to the kernel at 1314 boot time.) This means that it is a good idea to say Y here if you 1315 intend to use this kernel on different machines. 1316 1317 More information about the internals of the Linux math coprocessor 1318 emulation can be found in <file:arch/x86/math-emu/README>. 1319 1320 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1321 kernel, it won't hurt. 1322 1323config MTRR 1324 bool "MTRR (Memory Type Range Register) support" 1325 ---help--- 1326 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1327 the Memory Type Range Registers (MTRRs) may be used to control 1328 processor access to memory ranges. This is most useful if you have 1329 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1330 allows bus write transfers to be combined into a larger transfer 1331 before bursting over the PCI/AGP bus. This can increase performance 1332 of image write operations 2.5 times or more. Saying Y here creates a 1333 /proc/mtrr file which may be used to manipulate your processor's 1334 MTRRs. Typically the X server should use this. 1335 1336 This code has a reasonably generic interface so that similar 1337 control registers on other processors can be easily supported 1338 as well: 1339 1340 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1341 Registers (ARRs) which provide a similar functionality to MTRRs. For 1342 these, the ARRs are used to emulate the MTRRs. 1343 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1344 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1345 write-combining. All of these processors are supported by this code 1346 and it makes sense to say Y here if you have one of them. 1347 1348 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1349 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1350 can lead to all sorts of problems, so it's good to say Y here. 1351 1352 You can safely say Y even if your machine doesn't have MTRRs, you'll 1353 just add about 9 KB to your kernel. 1354 1355 See <file:Documentation/x86/mtrr.txt> for more information. 1356 1357config MTRR_SANITIZER 1358 def_bool y 1359 prompt "MTRR cleanup support" 1360 depends on MTRR 1361 ---help--- 1362 Convert MTRR layout from continuous to discrete, so X drivers can 1363 add writeback entries. 1364 1365 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1366 The largest mtrr entry size for a continuous block can be set with 1367 mtrr_chunk_size. 1368 1369 If unsure, say Y. 1370 1371config MTRR_SANITIZER_ENABLE_DEFAULT 1372 int "MTRR cleanup enable value (0-1)" 1373 range 0 1 1374 default "0" 1375 depends on MTRR_SANITIZER 1376 ---help--- 1377 Enable mtrr cleanup default value 1378 1379config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1380 int "MTRR cleanup spare reg num (0-7)" 1381 range 0 7 1382 default "1" 1383 depends on MTRR_SANITIZER 1384 ---help--- 1385 mtrr cleanup spare entries default, it can be changed via 1386 mtrr_spare_reg_nr=N on the kernel command line. 1387 1388config X86_PAT 1389 bool 1390 prompt "x86 PAT support" 1391 depends on MTRR 1392 ---help--- 1393 Use PAT attributes to setup page level cache control. 1394 1395 PATs are the modern equivalents of MTRRs and are much more 1396 flexible than MTRRs. 1397 1398 Say N here if you see bootup problems (boot crash, boot hang, 1399 spontaneous reboots) or a non-working video driver. 1400 1401 If unsure, say Y. 1402 1403config ARCH_USES_PG_UNCACHED 1404 def_bool y 1405 depends on X86_PAT 1406 1407config EFI 1408 bool "EFI runtime service support" 1409 depends on ACPI 1410 ---help--- 1411 This enables the kernel to use EFI runtime services that are 1412 available (such as the EFI variable services). 1413 1414 This option is only useful on systems that have EFI firmware. 1415 In addition, you should use the latest ELILO loader available 1416 at <http://elilo.sourceforge.net> in order to take advantage 1417 of EFI runtime services. However, even with this option, the 1418 resultant kernel should continue to boot on existing non-EFI 1419 platforms. 1420 1421config SECCOMP 1422 def_bool y 1423 prompt "Enable seccomp to safely compute untrusted bytecode" 1424 ---help--- 1425 This kernel feature is useful for number crunching applications 1426 that may need to compute untrusted bytecode during their 1427 execution. By using pipes or other transports made available to 1428 the process as file descriptors supporting the read/write 1429 syscalls, it's possible to isolate those applications in 1430 their own address space using seccomp. Once seccomp is 1431 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1432 and the task is only allowed to execute a few safe syscalls 1433 defined by each seccomp mode. 1434 1435 If unsure, say Y. Only embedded should say N here. 1436 1437config CC_STACKPROTECTOR_ALL 1438 bool 1439 1440config CC_STACKPROTECTOR 1441 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" 1442 select CC_STACKPROTECTOR_ALL 1443 ---help--- 1444 This option turns on the -fstack-protector GCC feature. This 1445 feature puts, at the beginning of functions, a canary value on 1446 the stack just before the return address, and validates 1447 the value just before actually returning. Stack based buffer 1448 overflows (that need to overwrite this return address) now also 1449 overwrite the canary, which gets detected and the attack is then 1450 neutralized via a kernel panic. 1451 1452 This feature requires gcc version 4.2 or above, or a distribution 1453 gcc with the feature backported. Older versions are automatically 1454 detected and for those versions, this configuration option is 1455 ignored. (and a warning is printed during bootup) 1456 1457source kernel/Kconfig.hz 1458 1459config KEXEC 1460 bool "kexec system call" 1461 ---help--- 1462 kexec is a system call that implements the ability to shutdown your 1463 current kernel, and to start another kernel. It is like a reboot 1464 but it is independent of the system firmware. And like a reboot 1465 you can start any kernel with it, not just Linux. 1466 1467 The name comes from the similarity to the exec system call. 1468 1469 It is an ongoing process to be certain the hardware in a machine 1470 is properly shutdown, so do not be surprised if this code does not 1471 initially work for you. It may help to enable device hotplugging 1472 support. As of this writing the exact hardware interface is 1473 strongly in flux, so no good recommendation can be made. 1474 1475config CRASH_DUMP 1476 bool "kernel crash dumps" 1477 depends on X86_64 || (X86_32 && HIGHMEM) 1478 ---help--- 1479 Generate crash dump after being started by kexec. 1480 This should be normally only set in special crash dump kernels 1481 which are loaded in the main kernel with kexec-tools into 1482 a specially reserved region and then later executed after 1483 a crash by kdump/kexec. The crash dump kernel must be compiled 1484 to a memory address not used by the main kernel or BIOS using 1485 PHYSICAL_START, or it must be built as a relocatable image 1486 (CONFIG_RELOCATABLE=y). 1487 For more details see Documentation/kdump/kdump.txt 1488 1489config KEXEC_JUMP 1490 bool "kexec jump (EXPERIMENTAL)" 1491 depends on EXPERIMENTAL 1492 depends on KEXEC && HIBERNATION 1493 ---help--- 1494 Jump between original kernel and kexeced kernel and invoke 1495 code in physical address mode via KEXEC 1496 1497config PHYSICAL_START 1498 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) 1499 default "0x1000000" 1500 ---help--- 1501 This gives the physical address where the kernel is loaded. 1502 1503 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1504 bzImage will decompress itself to above physical address and 1505 run from there. Otherwise, bzImage will run from the address where 1506 it has been loaded by the boot loader and will ignore above physical 1507 address. 1508 1509 In normal kdump cases one does not have to set/change this option 1510 as now bzImage can be compiled as a completely relocatable image 1511 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1512 address. This option is mainly useful for the folks who don't want 1513 to use a bzImage for capturing the crash dump and want to use a 1514 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1515 to be specifically compiled to run from a specific memory area 1516 (normally a reserved region) and this option comes handy. 1517 1518 So if you are using bzImage for capturing the crash dump, 1519 leave the value here unchanged to 0x1000000 and set 1520 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1521 for capturing the crash dump change this value to start of 1522 the reserved region. In other words, it can be set based on 1523 the "X" value as specified in the "crashkernel=YM@XM" 1524 command line boot parameter passed to the panic-ed 1525 kernel. Please take a look at Documentation/kdump/kdump.txt 1526 for more details about crash dumps. 1527 1528 Usage of bzImage for capturing the crash dump is recommended as 1529 one does not have to build two kernels. Same kernel can be used 1530 as production kernel and capture kernel. Above option should have 1531 gone away after relocatable bzImage support is introduced. But it 1532 is present because there are users out there who continue to use 1533 vmlinux for dump capture. This option should go away down the 1534 line. 1535 1536 Don't change this unless you know what you are doing. 1537 1538config RELOCATABLE 1539 bool "Build a relocatable kernel" 1540 default y 1541 ---help--- 1542 This builds a kernel image that retains relocation information 1543 so it can be loaded someplace besides the default 1MB. 1544 The relocations tend to make the kernel binary about 10% larger, 1545 but are discarded at runtime. 1546 1547 One use is for the kexec on panic case where the recovery kernel 1548 must live at a different physical address than the primary 1549 kernel. 1550 1551 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1552 it has been loaded at and the compile time physical address 1553 (CONFIG_PHYSICAL_START) is ignored. 1554 1555# Relocation on x86-32 needs some additional build support 1556config X86_NEED_RELOCS 1557 def_bool y 1558 depends on X86_32 && RELOCATABLE 1559 1560config PHYSICAL_ALIGN 1561 hex 1562 prompt "Alignment value to which kernel should be aligned" if X86_32 1563 default "0x1000000" 1564 range 0x2000 0x1000000 1565 ---help--- 1566 This value puts the alignment restrictions on physical address 1567 where kernel is loaded and run from. Kernel is compiled for an 1568 address which meets above alignment restriction. 1569 1570 If bootloader loads the kernel at a non-aligned address and 1571 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1572 address aligned to above value and run from there. 1573 1574 If bootloader loads the kernel at a non-aligned address and 1575 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1576 load address and decompress itself to the address it has been 1577 compiled for and run from there. The address for which kernel is 1578 compiled already meets above alignment restrictions. Hence the 1579 end result is that kernel runs from a physical address meeting 1580 above alignment restrictions. 1581 1582 Don't change this unless you know what you are doing. 1583 1584config HOTPLUG_CPU 1585 bool "Support for hot-pluggable CPUs" 1586 depends on SMP && HOTPLUG 1587 ---help--- 1588 Say Y here to allow turning CPUs off and on. CPUs can be 1589 controlled through /sys/devices/system/cpu. 1590 ( Note: power management support will enable this option 1591 automatically on SMP systems. ) 1592 Say N if you want to disable CPU hotplug. 1593 1594config COMPAT_VDSO 1595 def_bool y 1596 prompt "Compat VDSO support" 1597 depends on X86_32 || IA32_EMULATION 1598 ---help--- 1599 Map the 32-bit VDSO to the predictable old-style address too. 1600 ---help--- 1601 Say N here if you are running a sufficiently recent glibc 1602 version (2.3.3 or later), to remove the high-mapped 1603 VDSO mapping and to exclusively use the randomized VDSO. 1604 1605 If unsure, say Y. 1606 1607config CMDLINE_BOOL 1608 bool "Built-in kernel command line" 1609 default n 1610 ---help--- 1611 Allow for specifying boot arguments to the kernel at 1612 build time. On some systems (e.g. embedded ones), it is 1613 necessary or convenient to provide some or all of the 1614 kernel boot arguments with the kernel itself (that is, 1615 to not rely on the boot loader to provide them.) 1616 1617 To compile command line arguments into the kernel, 1618 set this option to 'Y', then fill in the 1619 the boot arguments in CONFIG_CMDLINE. 1620 1621 Systems with fully functional boot loaders (i.e. non-embedded) 1622 should leave this option set to 'N'. 1623 1624config CMDLINE 1625 string "Built-in kernel command string" 1626 depends on CMDLINE_BOOL 1627 default "" 1628 ---help--- 1629 Enter arguments here that should be compiled into the kernel 1630 image and used at boot time. If the boot loader provides a 1631 command line at boot time, it is appended to this string to 1632 form the full kernel command line, when the system boots. 1633 1634 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1635 change this behavior. 1636 1637 In most cases, the command line (whether built-in or provided 1638 by the boot loader) should specify the device for the root 1639 file system. 1640 1641config CMDLINE_OVERRIDE 1642 bool "Built-in command line overrides boot loader arguments" 1643 default n 1644 depends on CMDLINE_BOOL 1645 ---help--- 1646 Set this option to 'Y' to have the kernel ignore the boot loader 1647 command line, and use ONLY the built-in command line. 1648 1649 This is used to work around broken boot loaders. This should 1650 be set to 'N' under normal conditions. 1651 1652endmenu 1653 1654config ARCH_ENABLE_MEMORY_HOTPLUG 1655 def_bool y 1656 depends on X86_64 || (X86_32 && HIGHMEM) 1657 1658config ARCH_ENABLE_MEMORY_HOTREMOVE 1659 def_bool y 1660 depends on MEMORY_HOTPLUG 1661 1662config HAVE_ARCH_EARLY_PFN_TO_NID 1663 def_bool X86_64 1664 depends on NUMA 1665 1666menu "Power management and ACPI options" 1667 1668config ARCH_HIBERNATION_HEADER 1669 def_bool y 1670 depends on X86_64 && HIBERNATION 1671 1672source "kernel/power/Kconfig" 1673 1674source "drivers/acpi/Kconfig" 1675 1676source "drivers/sfi/Kconfig" 1677 1678config X86_APM_BOOT 1679 bool 1680 default y 1681 depends on APM || APM_MODULE 1682 1683menuconfig APM 1684 tristate "APM (Advanced Power Management) BIOS support" 1685 depends on X86_32 && PM_SLEEP 1686 ---help--- 1687 APM is a BIOS specification for saving power using several different 1688 techniques. This is mostly useful for battery powered laptops with 1689 APM compliant BIOSes. If you say Y here, the system time will be 1690 reset after a RESUME operation, the /proc/apm device will provide 1691 battery status information, and user-space programs will receive 1692 notification of APM "events" (e.g. battery status change). 1693 1694 If you select "Y" here, you can disable actual use of the APM 1695 BIOS by passing the "apm=off" option to the kernel at boot time. 1696 1697 Note that the APM support is almost completely disabled for 1698 machines with more than one CPU. 1699 1700 In order to use APM, you will need supporting software. For location 1701 and more information, read <file:Documentation/power/pm.txt> and the 1702 Battery Powered Linux mini-HOWTO, available from 1703 <http://www.tldp.org/docs.html#howto>. 1704 1705 This driver does not spin down disk drives (see the hdparm(8) 1706 manpage ("man 8 hdparm") for that), and it doesn't turn off 1707 VESA-compliant "green" monitors. 1708 1709 This driver does not support the TI 4000M TravelMate and the ACER 1710 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1711 desktop machines also don't have compliant BIOSes, and this driver 1712 may cause those machines to panic during the boot phase. 1713 1714 Generally, if you don't have a battery in your machine, there isn't 1715 much point in using this driver and you should say N. If you get 1716 random kernel OOPSes or reboots that don't seem to be related to 1717 anything, try disabling/enabling this option (or disabling/enabling 1718 APM in your BIOS). 1719 1720 Some other things you should try when experiencing seemingly random, 1721 "weird" problems: 1722 1723 1) make sure that you have enough swap space and that it is 1724 enabled. 1725 2) pass the "no-hlt" option to the kernel 1726 3) switch on floating point emulation in the kernel and pass 1727 the "no387" option to the kernel 1728 4) pass the "floppy=nodma" option to the kernel 1729 5) pass the "mem=4M" option to the kernel (thereby disabling 1730 all but the first 4 MB of RAM) 1731 6) make sure that the CPU is not over clocked. 1732 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1733 8) disable the cache from your BIOS settings 1734 9) install a fan for the video card or exchange video RAM 1735 10) install a better fan for the CPU 1736 11) exchange RAM chips 1737 12) exchange the motherboard. 1738 1739 To compile this driver as a module, choose M here: the 1740 module will be called apm. 1741 1742if APM 1743 1744config APM_IGNORE_USER_SUSPEND 1745 bool "Ignore USER SUSPEND" 1746 ---help--- 1747 This option will ignore USER SUSPEND requests. On machines with a 1748 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1749 series notebooks, it is necessary to say Y because of a BIOS bug. 1750 1751config APM_DO_ENABLE 1752 bool "Enable PM at boot time" 1753 ---help--- 1754 Enable APM features at boot time. From page 36 of the APM BIOS 1755 specification: "When disabled, the APM BIOS does not automatically 1756 power manage devices, enter the Standby State, enter the Suspend 1757 State, or take power saving steps in response to CPU Idle calls." 1758 This driver will make CPU Idle calls when Linux is idle (unless this 1759 feature is turned off -- see "Do CPU IDLE calls", below). This 1760 should always save battery power, but more complicated APM features 1761 will be dependent on your BIOS implementation. You may need to turn 1762 this option off if your computer hangs at boot time when using APM 1763 support, or if it beeps continuously instead of suspending. Turn 1764 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1765 T400CDT. This is off by default since most machines do fine without 1766 this feature. 1767 1768config APM_CPU_IDLE 1769 bool "Make CPU Idle calls when idle" 1770 ---help--- 1771 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1772 On some machines, this can activate improved power savings, such as 1773 a slowed CPU clock rate, when the machine is idle. These idle calls 1774 are made after the idle loop has run for some length of time (e.g., 1775 333 mS). On some machines, this will cause a hang at boot time or 1776 whenever the CPU becomes idle. (On machines with more than one CPU, 1777 this option does nothing.) 1778 1779config APM_DISPLAY_BLANK 1780 bool "Enable console blanking using APM" 1781 ---help--- 1782 Enable console blanking using the APM. Some laptops can use this to 1783 turn off the LCD backlight when the screen blanker of the Linux 1784 virtual console blanks the screen. Note that this is only used by 1785 the virtual console screen blanker, and won't turn off the backlight 1786 when using the X Window system. This also doesn't have anything to 1787 do with your VESA-compliant power-saving monitor. Further, this 1788 option doesn't work for all laptops -- it might not turn off your 1789 backlight at all, or it might print a lot of errors to the console, 1790 especially if you are using gpm. 1791 1792config APM_ALLOW_INTS 1793 bool "Allow interrupts during APM BIOS calls" 1794 ---help--- 1795 Normally we disable external interrupts while we are making calls to 1796 the APM BIOS as a measure to lessen the effects of a badly behaving 1797 BIOS implementation. The BIOS should reenable interrupts if it 1798 needs to. Unfortunately, some BIOSes do not -- especially those in 1799 many of the newer IBM Thinkpads. If you experience hangs when you 1800 suspend, try setting this to Y. Otherwise, say N. 1801 1802endif # APM 1803 1804source "arch/x86/kernel/cpu/cpufreq/Kconfig" 1805 1806source "drivers/cpuidle/Kconfig" 1807 1808source "drivers/idle/Kconfig" 1809 1810endmenu 1811 1812 1813menu "Bus options (PCI etc.)" 1814 1815config PCI 1816 bool "PCI support" 1817 default y 1818 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC) 1819 ---help--- 1820 Find out whether you have a PCI motherboard. PCI is the name of a 1821 bus system, i.e. the way the CPU talks to the other stuff inside 1822 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 1823 VESA. If you have PCI, say Y, otherwise N. 1824 1825choice 1826 prompt "PCI access mode" 1827 depends on X86_32 && PCI 1828 default PCI_GOANY 1829 ---help--- 1830 On PCI systems, the BIOS can be used to detect the PCI devices and 1831 determine their configuration. However, some old PCI motherboards 1832 have BIOS bugs and may crash if this is done. Also, some embedded 1833 PCI-based systems don't have any BIOS at all. Linux can also try to 1834 detect the PCI hardware directly without using the BIOS. 1835 1836 With this option, you can specify how Linux should detect the 1837 PCI devices. If you choose "BIOS", the BIOS will be used, 1838 if you choose "Direct", the BIOS won't be used, and if you 1839 choose "MMConfig", then PCI Express MMCONFIG will be used. 1840 If you choose "Any", the kernel will try MMCONFIG, then the 1841 direct access method and falls back to the BIOS if that doesn't 1842 work. If unsure, go with the default, which is "Any". 1843 1844config PCI_GOBIOS 1845 bool "BIOS" 1846 1847config PCI_GOMMCONFIG 1848 bool "MMConfig" 1849 1850config PCI_GODIRECT 1851 bool "Direct" 1852 1853config PCI_GOOLPC 1854 bool "OLPC" 1855 depends on OLPC 1856 1857config PCI_GOANY 1858 bool "Any" 1859 1860endchoice 1861 1862config PCI_BIOS 1863 def_bool y 1864 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 1865 1866# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 1867config PCI_DIRECT 1868 def_bool y 1869 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC)) 1870 1871config PCI_MMCONFIG 1872 def_bool y 1873 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 1874 1875config PCI_OLPC 1876 def_bool y 1877 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 1878 1879config PCI_DOMAINS 1880 def_bool y 1881 depends on PCI 1882 1883config PCI_MMCONFIG 1884 bool "Support mmconfig PCI config space access" 1885 depends on X86_64 && PCI && ACPI 1886 1887config DMAR 1888 bool "Support for DMA Remapping Devices (EXPERIMENTAL)" 1889 depends on PCI_MSI && ACPI && EXPERIMENTAL 1890 help 1891 DMA remapping (DMAR) devices support enables independent address 1892 translations for Direct Memory Access (DMA) from devices. 1893 These DMA remapping devices are reported via ACPI tables 1894 and include PCI device scope covered by these DMA 1895 remapping devices. 1896 1897config DMAR_DEFAULT_ON 1898 def_bool y 1899 prompt "Enable DMA Remapping Devices by default" 1900 depends on DMAR 1901 help 1902 Selecting this option will enable a DMAR device at boot time if 1903 one is found. If this option is not selected, DMAR support can 1904 be enabled by passing intel_iommu=on to the kernel. It is 1905 recommended you say N here while the DMAR code remains 1906 experimental. 1907 1908config DMAR_BROKEN_GFX_WA 1909 def_bool n 1910 prompt "Workaround broken graphics drivers (going away soon)" 1911 depends on DMAR && BROKEN 1912 ---help--- 1913 Current Graphics drivers tend to use physical address 1914 for DMA and avoid using DMA APIs. Setting this config 1915 option permits the IOMMU driver to set a unity map for 1916 all the OS-visible memory. Hence the driver can continue 1917 to use physical addresses for DMA, at least until this 1918 option is removed in the 2.6.32 kernel. 1919 1920config DMAR_FLOPPY_WA 1921 def_bool y 1922 depends on DMAR 1923 ---help--- 1924 Floppy disk drivers are known to bypass DMA API calls 1925 thereby failing to work when IOMMU is enabled. This 1926 workaround will setup a 1:1 mapping for the first 1927 16MiB to make floppy (an ISA device) work. 1928 1929config INTR_REMAP 1930 bool "Support for Interrupt Remapping (EXPERIMENTAL)" 1931 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL 1932 ---help--- 1933 Supports Interrupt remapping for IO-APIC and MSI devices. 1934 To use x2apic mode in the CPU's which support x2APIC enhancements or 1935 to support platforms with CPU's having > 8 bit APIC ID, say Y. 1936 1937source "drivers/pci/pcie/Kconfig" 1938 1939source "drivers/pci/Kconfig" 1940 1941# x86_64 have no ISA slots, but do have ISA-style DMA. 1942config ISA_DMA_API 1943 def_bool y 1944 1945if X86_32 1946 1947config ISA 1948 bool "ISA support" 1949 ---help--- 1950 Find out whether you have ISA slots on your motherboard. ISA is the 1951 name of a bus system, i.e. the way the CPU talks to the other stuff 1952 inside your box. Other bus systems are PCI, EISA, MicroChannel 1953 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 1954 newer boards don't support it. If you have ISA, say Y, otherwise N. 1955 1956config EISA 1957 bool "EISA support" 1958 depends on ISA 1959 ---help--- 1960 The Extended Industry Standard Architecture (EISA) bus was 1961 developed as an open alternative to the IBM MicroChannel bus. 1962 1963 The EISA bus provided some of the features of the IBM MicroChannel 1964 bus while maintaining backward compatibility with cards made for 1965 the older ISA bus. The EISA bus saw limited use between 1988 and 1966 1995 when it was made obsolete by the PCI bus. 1967 1968 Say Y here if you are building a kernel for an EISA-based machine. 1969 1970 Otherwise, say N. 1971 1972source "drivers/eisa/Kconfig" 1973 1974config MCA 1975 bool "MCA support" 1976 ---help--- 1977 MicroChannel Architecture is found in some IBM PS/2 machines and 1978 laptops. It is a bus system similar to PCI or ISA. See 1979 <file:Documentation/mca.txt> (and especially the web page given 1980 there) before attempting to build an MCA bus kernel. 1981 1982source "drivers/mca/Kconfig" 1983 1984config SCx200 1985 tristate "NatSemi SCx200 support" 1986 ---help--- 1987 This provides basic support for National Semiconductor's 1988 (now AMD's) Geode processors. The driver probes for the 1989 PCI-IDs of several on-chip devices, so its a good dependency 1990 for other scx200_* drivers. 1991 1992 If compiled as a module, the driver is named scx200. 1993 1994config SCx200HR_TIMER 1995 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 1996 depends on SCx200 && GENERIC_TIME 1997 default y 1998 ---help--- 1999 This driver provides a clocksource built upon the on-chip 2000 27MHz high-resolution timer. Its also a workaround for 2001 NSC Geode SC-1100's buggy TSC, which loses time when the 2002 processor goes idle (as is done by the scheduler). The 2003 other workaround is idle=poll boot option. 2004 2005config GEODE_MFGPT_TIMER 2006 def_bool y 2007 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events" 2008 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS 2009 ---help--- 2010 This driver provides a clock event source based on the MFGPT 2011 timer(s) in the CS5535 and CS5536 companion chip for the geode. 2012 MFGPTs have a better resolution and max interval than the 2013 generic PIT, and are suitable for use as high-res timers. 2014 2015config OLPC 2016 bool "One Laptop Per Child support" 2017 default n 2018 ---help--- 2019 Add support for detecting the unique features of the OLPC 2020 XO hardware. 2021 2022endif # X86_32 2023 2024config K8_NB 2025 def_bool y 2026 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA))) 2027 2028source "drivers/pcmcia/Kconfig" 2029 2030source "drivers/pci/hotplug/Kconfig" 2031 2032endmenu 2033 2034 2035menu "Executable file formats / Emulations" 2036 2037source "fs/Kconfig.binfmt" 2038 2039config IA32_EMULATION 2040 bool "IA32 Emulation" 2041 depends on X86_64 2042 select COMPAT_BINFMT_ELF 2043 ---help--- 2044 Include code to run 32-bit programs under a 64-bit kernel. You should 2045 likely turn this on, unless you're 100% sure that you don't have any 2046 32-bit programs left. 2047 2048config IA32_AOUT 2049 tristate "IA32 a.out support" 2050 depends on IA32_EMULATION 2051 ---help--- 2052 Support old a.out binaries in the 32bit emulation. 2053 2054config COMPAT 2055 def_bool y 2056 depends on IA32_EMULATION 2057 2058config COMPAT_FOR_U64_ALIGNMENT 2059 def_bool COMPAT 2060 depends on X86_64 2061 2062config SYSVIPC_COMPAT 2063 def_bool y 2064 depends on COMPAT && SYSVIPC 2065 2066endmenu 2067 2068 2069config HAVE_ATOMIC_IOMAP 2070 def_bool y 2071 depends on X86_32 2072 2073source "net/Kconfig" 2074 2075source "drivers/Kconfig" 2076 2077source "drivers/firmware/Kconfig" 2078 2079source "fs/Kconfig" 2080 2081source "arch/x86/Kconfig.debug" 2082 2083source "security/Kconfig" 2084 2085source "crypto/Kconfig" 2086 2087source "arch/x86/kvm/Kconfig" 2088 2089source "lib/Kconfig" 2090