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_COUNTERS 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 328 329 If you have one of these systems, or if you want to build a 330 generic distribution kernel, say Y here - otherwise say N. 331endif 332 333if X86_64 334config X86_EXTENDED_PLATFORM 335 bool "Support for extended (non-PC) x86 platforms" 336 default y 337 ---help--- 338 If you disable this option then the kernel will only support 339 standard PC platforms. (which covers the vast majority of 340 systems out there.) 341 342 If you enable this option then you'll be able to select support 343 for the following (non-PC) 64 bit x86 platforms: 344 ScaleMP vSMP 345 SGI Ultraviolet 346 347 If you have one of these systems, or if you want to build a 348 generic distribution kernel, say Y here - otherwise say N. 349endif 350# This is an alphabetically sorted list of 64 bit extended platforms 351# Please maintain the alphabetic order if and when there are additions 352 353config X86_VSMP 354 bool "ScaleMP vSMP" 355 select PARAVIRT 356 depends on X86_64 && PCI 357 depends on X86_EXTENDED_PLATFORM 358 ---help--- 359 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 360 supposed to run on these EM64T-based machines. Only choose this option 361 if you have one of these machines. 362 363config X86_UV 364 bool "SGI Ultraviolet" 365 depends on X86_64 366 depends on X86_EXTENDED_PLATFORM 367 depends on NUMA 368 depends on X86_X2APIC 369 ---help--- 370 This option is needed in order to support SGI Ultraviolet systems. 371 If you don't have one of these, you should say N here. 372 373# Following is an alphabetically sorted list of 32 bit extended platforms 374# Please maintain the alphabetic order if and when there are additions 375 376config X86_ELAN 377 bool "AMD Elan" 378 depends on X86_32 379 depends on X86_EXTENDED_PLATFORM 380 ---help--- 381 Select this for an AMD Elan processor. 382 383 Do not use this option for K6/Athlon/Opteron processors! 384 385 If unsure, choose "PC-compatible" instead. 386 387config X86_RDC321X 388 bool "RDC R-321x SoC" 389 depends on X86_32 390 depends on X86_EXTENDED_PLATFORM 391 select M486 392 select X86_REBOOTFIXUPS 393 ---help--- 394 This option is needed for RDC R-321x system-on-chip, also known 395 as R-8610-(G). 396 If you don't have one of these chips, you should say N here. 397 398config X86_32_NON_STANDARD 399 bool "Support non-standard 32-bit SMP architectures" 400 depends on X86_32 && SMP 401 depends on X86_EXTENDED_PLATFORM 402 ---help--- 403 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default 404 subarchitectures. It is intended for a generic binary kernel. 405 if you select them all, kernel will probe it one by one. and will 406 fallback to default. 407 408# Alphabetically sorted list of Non standard 32 bit platforms 409 410config X86_NUMAQ 411 bool "NUMAQ (IBM/Sequent)" 412 depends on X86_32_NON_STANDARD 413 select NUMA 414 select X86_MPPARSE 415 ---help--- 416 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent) 417 NUMA multiquad box. This changes the way that processors are 418 bootstrapped, and uses Clustered Logical APIC addressing mode instead 419 of Flat Logical. You will need a new lynxer.elf file to flash your 420 firmware with - send email to <Martin.Bligh@us.ibm.com>. 421 422config X86_VISWS 423 bool "SGI 320/540 (Visual Workstation)" 424 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT 425 depends on X86_32_NON_STANDARD 426 ---help--- 427 The SGI Visual Workstation series is an IA32-based workstation 428 based on SGI systems chips with some legacy PC hardware attached. 429 430 Say Y here to create a kernel to run on the SGI 320 or 540. 431 432 A kernel compiled for the Visual Workstation will run on general 433 PCs as well. See <file:Documentation/sgi-visws.txt> for details. 434 435config X86_SUMMIT 436 bool "Summit/EXA (IBM x440)" 437 depends on X86_32_NON_STANDARD 438 ---help--- 439 This option is needed for IBM systems that use the Summit/EXA chipset. 440 In particular, it is needed for the x440. 441 442config X86_ES7000 443 bool "Unisys ES7000 IA32 series" 444 depends on X86_32_NON_STANDARD && X86_BIGSMP 445 ---help--- 446 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 447 supposed to run on an IA32-based Unisys ES7000 system. 448 449config SCHED_OMIT_FRAME_POINTER 450 def_bool y 451 prompt "Single-depth WCHAN output" 452 depends on X86 453 ---help--- 454 Calculate simpler /proc/<PID>/wchan values. If this option 455 is disabled then wchan values will recurse back to the 456 caller function. This provides more accurate wchan values, 457 at the expense of slightly more scheduling overhead. 458 459 If in doubt, say "Y". 460 461menuconfig PARAVIRT_GUEST 462 bool "Paravirtualized guest support" 463 ---help--- 464 Say Y here to get to see options related to running Linux under 465 various hypervisors. This option alone does not add any kernel code. 466 467 If you say N, all options in this submenu will be skipped and disabled. 468 469if PARAVIRT_GUEST 470 471source "arch/x86/xen/Kconfig" 472 473config VMI 474 bool "VMI Guest support" 475 select PARAVIRT 476 depends on X86_32 477 ---help--- 478 VMI provides a paravirtualized interface to the VMware ESX server 479 (it could be used by other hypervisors in theory too, but is not 480 at the moment), by linking the kernel to a GPL-ed ROM module 481 provided by the hypervisor. 482 483config KVM_CLOCK 484 bool "KVM paravirtualized clock" 485 select PARAVIRT 486 select PARAVIRT_CLOCK 487 ---help--- 488 Turning on this option will allow you to run a paravirtualized clock 489 when running over the KVM hypervisor. Instead of relying on a PIT 490 (or probably other) emulation by the underlying device model, the host 491 provides the guest with timing infrastructure such as time of day, and 492 system time 493 494config KVM_GUEST 495 bool "KVM Guest support" 496 select PARAVIRT 497 ---help--- 498 This option enables various optimizations for running under the KVM 499 hypervisor. 500 501source "arch/x86/lguest/Kconfig" 502 503config PARAVIRT 504 bool "Enable paravirtualization code" 505 ---help--- 506 This changes the kernel so it can modify itself when it is run 507 under a hypervisor, potentially improving performance significantly 508 over full virtualization. However, when run without a hypervisor 509 the kernel is theoretically slower and slightly larger. 510 511config PARAVIRT_SPINLOCKS 512 bool "Paravirtualization layer for spinlocks" 513 depends on PARAVIRT && SMP && EXPERIMENTAL 514 ---help--- 515 Paravirtualized spinlocks allow a pvops backend to replace the 516 spinlock implementation with something virtualization-friendly 517 (for example, block the virtual CPU rather than spinning). 518 519 Unfortunately the downside is an up to 5% performance hit on 520 native kernels, with various workloads. 521 522 If you are unsure how to answer this question, answer N. 523 524config PARAVIRT_CLOCK 525 bool 526 default n 527 528endif 529 530config PARAVIRT_DEBUG 531 bool "paravirt-ops debugging" 532 depends on PARAVIRT && DEBUG_KERNEL 533 ---help--- 534 Enable to debug paravirt_ops internals. Specifically, BUG if 535 a paravirt_op is missing when it is called. 536 537config MEMTEST 538 bool "Memtest" 539 ---help--- 540 This option adds a kernel parameter 'memtest', which allows memtest 541 to be set. 542 memtest=0, mean disabled; -- default 543 memtest=1, mean do 1 test pattern; 544 ... 545 memtest=4, mean do 4 test patterns. 546 If you are unsure how to answer this question, answer N. 547 548config X86_SUMMIT_NUMA 549 def_bool y 550 depends on X86_32 && NUMA && X86_32_NON_STANDARD 551 552config X86_CYCLONE_TIMER 553 def_bool y 554 depends on X86_32_NON_STANDARD 555 556source "arch/x86/Kconfig.cpu" 557 558config HPET_TIMER 559 def_bool X86_64 560 prompt "HPET Timer Support" if X86_32 561 ---help--- 562 Use the IA-PC HPET (High Precision Event Timer) to manage 563 time in preference to the PIT and RTC, if a HPET is 564 present. 565 HPET is the next generation timer replacing legacy 8254s. 566 The HPET provides a stable time base on SMP 567 systems, unlike the TSC, but it is more expensive to access, 568 as it is off-chip. You can find the HPET spec at 569 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 570 571 You can safely choose Y here. However, HPET will only be 572 activated if the platform and the BIOS support this feature. 573 Otherwise the 8254 will be used for timing services. 574 575 Choose N to continue using the legacy 8254 timer. 576 577config HPET_EMULATE_RTC 578 def_bool y 579 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 580 581# Mark as embedded because too many people got it wrong. 582# The code disables itself when not needed. 583config DMI 584 default y 585 bool "Enable DMI scanning" if EMBEDDED 586 ---help--- 587 Enabled scanning of DMI to identify machine quirks. Say Y 588 here unless you have verified that your setup is not 589 affected by entries in the DMI blacklist. Required by PNP 590 BIOS code. 591 592config GART_IOMMU 593 bool "GART IOMMU support" if EMBEDDED 594 default y 595 select SWIOTLB 596 depends on X86_64 && PCI 597 ---help--- 598 Support for full DMA access of devices with 32bit memory access only 599 on systems with more than 3GB. This is usually needed for USB, 600 sound, many IDE/SATA chipsets and some other devices. 601 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART 602 based hardware IOMMU and a software bounce buffer based IOMMU used 603 on Intel systems and as fallback. 604 The code is only active when needed (enough memory and limited 605 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified 606 too. 607 608config CALGARY_IOMMU 609 bool "IBM Calgary IOMMU support" 610 select SWIOTLB 611 depends on X86_64 && PCI && EXPERIMENTAL 612 ---help--- 613 Support for hardware IOMMUs in IBM's xSeries x366 and x460 614 systems. Needed to run systems with more than 3GB of memory 615 properly with 32-bit PCI devices that do not support DAC 616 (Double Address Cycle). Calgary also supports bus level 617 isolation, where all DMAs pass through the IOMMU. This 618 prevents them from going anywhere except their intended 619 destination. This catches hard-to-find kernel bugs and 620 mis-behaving drivers and devices that do not use the DMA-API 621 properly to set up their DMA buffers. The IOMMU can be 622 turned off at boot time with the iommu=off parameter. 623 Normally the kernel will make the right choice by itself. 624 If unsure, say Y. 625 626config CALGARY_IOMMU_ENABLED_BY_DEFAULT 627 def_bool y 628 prompt "Should Calgary be enabled by default?" 629 depends on CALGARY_IOMMU 630 ---help--- 631 Should Calgary be enabled by default? if you choose 'y', Calgary 632 will be used (if it exists). If you choose 'n', Calgary will not be 633 used even if it exists. If you choose 'n' and would like to use 634 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 635 If unsure, say Y. 636 637config AMD_IOMMU 638 bool "AMD IOMMU support" 639 select SWIOTLB 640 select PCI_MSI 641 depends on X86_64 && PCI && ACPI 642 ---help--- 643 With this option you can enable support for AMD IOMMU hardware in 644 your system. An IOMMU is a hardware component which provides 645 remapping of DMA memory accesses from devices. With an AMD IOMMU you 646 can isolate the the DMA memory of different devices and protect the 647 system from misbehaving device drivers or hardware. 648 649 You can find out if your system has an AMD IOMMU if you look into 650 your BIOS for an option to enable it or if you have an IVRS ACPI 651 table. 652 653config AMD_IOMMU_STATS 654 bool "Export AMD IOMMU statistics to debugfs" 655 depends on AMD_IOMMU 656 select DEBUG_FS 657 ---help--- 658 This option enables code in the AMD IOMMU driver to collect various 659 statistics about whats happening in the driver and exports that 660 information to userspace via debugfs. 661 If unsure, say N. 662 663# need this always selected by IOMMU for the VIA workaround 664config SWIOTLB 665 def_bool y if X86_64 666 ---help--- 667 Support for software bounce buffers used on x86-64 systems 668 which don't have a hardware IOMMU (e.g. the current generation 669 of Intel's x86-64 CPUs). Using this PCI devices which can only 670 access 32-bits of memory can be used on systems with more than 671 3 GB of memory. If unsure, say Y. 672 673config IOMMU_HELPER 674 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU) 675 676config IOMMU_API 677 def_bool (AMD_IOMMU || DMAR) 678 679config MAXSMP 680 bool "Configure Maximum number of SMP Processors and NUMA Nodes" 681 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL 682 select CPUMASK_OFFSTACK 683 default n 684 ---help--- 685 Configure maximum number of CPUS and NUMA Nodes for this architecture. 686 If unsure, say N. 687 688config NR_CPUS 689 int "Maximum number of CPUs" if SMP && !MAXSMP 690 range 2 8 if SMP && X86_32 && !X86_BIGSMP 691 range 2 512 if SMP && !MAXSMP 692 default "1" if !SMP 693 default "4096" if MAXSMP 694 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000) 695 default "8" if SMP 696 ---help--- 697 This allows you to specify the maximum number of CPUs which this 698 kernel will support. The maximum supported value is 512 and the 699 minimum value which makes sense is 2. 700 701 This is purely to save memory - each supported CPU adds 702 approximately eight kilobytes to the kernel image. 703 704config SCHED_SMT 705 bool "SMT (Hyperthreading) scheduler support" 706 depends on X86_HT 707 ---help--- 708 SMT scheduler support improves the CPU scheduler's decision making 709 when dealing with Intel Pentium 4 chips with HyperThreading at a 710 cost of slightly increased overhead in some places. If unsure say 711 N here. 712 713config SCHED_MC 714 def_bool y 715 prompt "Multi-core scheduler support" 716 depends on X86_HT 717 ---help--- 718 Multi-core scheduler support improves the CPU scheduler's decision 719 making when dealing with multi-core CPU chips at a cost of slightly 720 increased overhead in some places. If unsure say N here. 721 722source "kernel/Kconfig.preempt" 723 724config X86_UP_APIC 725 bool "Local APIC support on uniprocessors" 726 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 727 ---help--- 728 A local APIC (Advanced Programmable Interrupt Controller) is an 729 integrated interrupt controller in the CPU. If you have a single-CPU 730 system which has a processor with a local APIC, you can say Y here to 731 enable and use it. If you say Y here even though your machine doesn't 732 have a local APIC, then the kernel will still run with no slowdown at 733 all. The local APIC supports CPU-generated self-interrupts (timer, 734 performance counters), and the NMI watchdog which detects hard 735 lockups. 736 737config X86_UP_IOAPIC 738 bool "IO-APIC support on uniprocessors" 739 depends on X86_UP_APIC 740 ---help--- 741 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 742 SMP-capable replacement for PC-style interrupt controllers. Most 743 SMP systems and many recent uniprocessor systems have one. 744 745 If you have a single-CPU system with an IO-APIC, you can say Y here 746 to use it. If you say Y here even though your machine doesn't have 747 an IO-APIC, then the kernel will still run with no slowdown at all. 748 749config X86_LOCAL_APIC 750 def_bool y 751 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC 752 753config X86_IO_APIC 754 def_bool y 755 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC 756 757config X86_VISWS_APIC 758 def_bool y 759 depends on X86_32 && X86_VISWS 760 761config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 762 bool "Reroute for broken boot IRQs" 763 default n 764 depends on X86_IO_APIC 765 ---help--- 766 This option enables a workaround that fixes a source of 767 spurious interrupts. This is recommended when threaded 768 interrupt handling is used on systems where the generation of 769 superfluous "boot interrupts" cannot be disabled. 770 771 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 772 entry in the chipset's IO-APIC is masked (as, e.g. the RT 773 kernel does during interrupt handling). On chipsets where this 774 boot IRQ generation cannot be disabled, this workaround keeps 775 the original IRQ line masked so that only the equivalent "boot 776 IRQ" is delivered to the CPUs. The workaround also tells the 777 kernel to set up the IRQ handler on the boot IRQ line. In this 778 way only one interrupt is delivered to the kernel. Otherwise 779 the spurious second interrupt may cause the kernel to bring 780 down (vital) interrupt lines. 781 782 Only affects "broken" chipsets. Interrupt sharing may be 783 increased on these systems. 784 785config X86_MCE 786 bool "Machine Check Exception" 787 ---help--- 788 Machine Check Exception support allows the processor to notify the 789 kernel if it detects a problem (e.g. overheating, component failure). 790 The action the kernel takes depends on the severity of the problem, 791 ranging from a warning message on the console, to halting the machine. 792 Your processor must be a Pentium or newer to support this - check the 793 flags in /proc/cpuinfo for mce. Note that some older Pentium systems 794 have a design flaw which leads to false MCE events - hence MCE is 795 disabled on all P5 processors, unless explicitly enabled with "mce" 796 as a boot argument. Similarly, if MCE is built in and creates a 797 problem on some new non-standard machine, you can boot with "nomce" 798 to disable it. MCE support simply ignores non-MCE processors like 799 the 386 and 486, so nearly everyone can say Y here. 800 801config X86_OLD_MCE 802 depends on X86_32 && X86_MCE 803 bool "Use legacy machine check code (will go away)" 804 default n 805 select X86_ANCIENT_MCE 806 ---help--- 807 Use the old i386 machine check code. This is merely intended for 808 testing in a transition period. Try this if you run into any machine 809 check related software problems, but report the problem to 810 linux-kernel. When in doubt say no. 811 812config X86_NEW_MCE 813 depends on X86_MCE 814 bool 815 default y if (!X86_OLD_MCE && X86_32) || X86_64 816 817config X86_MCE_INTEL 818 def_bool y 819 prompt "Intel MCE features" 820 depends on X86_NEW_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_NEW_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_32 836 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_NEW_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_MCE_NONFATAL 856 tristate "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4" 857 depends on X86_OLD_MCE 858 ---help--- 859 Enabling this feature starts a timer that triggers every 5 seconds which 860 will look at the machine check registers to see if anything happened. 861 Non-fatal problems automatically get corrected (but still logged). 862 Disable this if you don't want to see these messages. 863 Seeing the messages this option prints out may be indicative of dying 864 or out-of-spec (ie, overclocked) hardware. 865 This option only does something on certain CPUs. 866 (AMD Athlon/Duron and Intel Pentium 4) 867 868config X86_MCE_P4THERMAL 869 bool "check for P4 thermal throttling interrupt." 870 depends on X86_OLD_MCE && X86_MCE && (X86_UP_APIC || SMP) 871 ---help--- 872 Enabling this feature will cause a message to be printed when the P4 873 enters thermal throttling. 874 875config X86_THERMAL_VECTOR 876 def_bool y 877 depends on X86_MCE_P4THERMAL || X86_MCE_INTEL 878 879config VM86 880 bool "Enable VM86 support" if EMBEDDED 881 default y 882 depends on X86_32 883 ---help--- 884 This option is required by programs like DOSEMU to run 16-bit legacy 885 code on X86 processors. It also may be needed by software like 886 XFree86 to initialize some video cards via BIOS. Disabling this 887 option saves about 6k. 888 889config TOSHIBA 890 tristate "Toshiba Laptop support" 891 depends on X86_32 892 ---help--- 893 This adds a driver to safely access the System Management Mode of 894 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 895 not work on models with a Phoenix BIOS. The System Management Mode 896 is used to set the BIOS and power saving options on Toshiba portables. 897 898 For information on utilities to make use of this driver see the 899 Toshiba Linux utilities web site at: 900 <http://www.buzzard.org.uk/toshiba/>. 901 902 Say Y if you intend to run this kernel on a Toshiba portable. 903 Say N otherwise. 904 905config I8K 906 tristate "Dell laptop support" 907 ---help--- 908 This adds a driver to safely access the System Management Mode 909 of the CPU on the Dell Inspiron 8000. The System Management Mode 910 is used to read cpu temperature and cooling fan status and to 911 control the fans on the I8K portables. 912 913 This driver has been tested only on the Inspiron 8000 but it may 914 also work with other Dell laptops. You can force loading on other 915 models by passing the parameter `force=1' to the module. Use at 916 your own risk. 917 918 For information on utilities to make use of this driver see the 919 I8K Linux utilities web site at: 920 <http://people.debian.org/~dz/i8k/> 921 922 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 923 Say N otherwise. 924 925config X86_REBOOTFIXUPS 926 bool "Enable X86 board specific fixups for reboot" 927 depends on X86_32 928 ---help--- 929 This enables chipset and/or board specific fixups to be done 930 in order to get reboot to work correctly. This is only needed on 931 some combinations of hardware and BIOS. The symptom, for which 932 this config is intended, is when reboot ends with a stalled/hung 933 system. 934 935 Currently, the only fixup is for the Geode machines using 936 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 937 938 Say Y if you want to enable the fixup. Currently, it's safe to 939 enable this option even if you don't need it. 940 Say N otherwise. 941 942config MICROCODE 943 tristate "/dev/cpu/microcode - microcode support" 944 select FW_LOADER 945 ---help--- 946 If you say Y here, you will be able to update the microcode on 947 certain Intel and AMD processors. The Intel support is for the 948 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, 949 Pentium 4, Xeon etc. The AMD support is for family 0x10 and 950 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra. 951 You will obviously need the actual microcode binary data itself 952 which is not shipped with the Linux kernel. 953 954 This option selects the general module only, you need to select 955 at least one vendor specific module as well. 956 957 To compile this driver as a module, choose M here: the 958 module will be called microcode. 959 960config MICROCODE_INTEL 961 bool "Intel microcode patch loading support" 962 depends on MICROCODE 963 default MICROCODE 964 select FW_LOADER 965 ---help--- 966 This options enables microcode patch loading support for Intel 967 processors. 968 969 For latest news and information on obtaining all the required 970 Intel ingredients for this driver, check: 971 <http://www.urbanmyth.org/microcode/>. 972 973config MICROCODE_AMD 974 bool "AMD microcode patch loading support" 975 depends on MICROCODE 976 select FW_LOADER 977 ---help--- 978 If you select this option, microcode patch loading support for AMD 979 processors will be enabled. 980 981config MICROCODE_OLD_INTERFACE 982 def_bool y 983 depends on MICROCODE 984 985config X86_MSR 986 tristate "/dev/cpu/*/msr - Model-specific register support" 987 ---help--- 988 This device gives privileged processes access to the x86 989 Model-Specific Registers (MSRs). It is a character device with 990 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 991 MSR accesses are directed to a specific CPU on multi-processor 992 systems. 993 994config X86_CPUID 995 tristate "/dev/cpu/*/cpuid - CPU information support" 996 ---help--- 997 This device gives processes access to the x86 CPUID instruction to 998 be executed on a specific processor. It is a character device 999 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1000 /dev/cpu/31/cpuid. 1001 1002config X86_CPU_DEBUG 1003 tristate "/sys/kernel/debug/x86/cpu/* - CPU Debug support" 1004 ---help--- 1005 If you select this option, this will provide various x86 CPUs 1006 information through debugfs. 1007 1008choice 1009 prompt "High Memory Support" 1010 default HIGHMEM4G if !X86_NUMAQ 1011 default HIGHMEM64G if X86_NUMAQ 1012 depends on X86_32 1013 1014config NOHIGHMEM 1015 bool "off" 1016 depends on !X86_NUMAQ 1017 ---help--- 1018 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1019 However, the address space of 32-bit x86 processors is only 4 1020 Gigabytes large. That means that, if you have a large amount of 1021 physical memory, not all of it can be "permanently mapped" by the 1022 kernel. The physical memory that's not permanently mapped is called 1023 "high memory". 1024 1025 If you are compiling a kernel which will never run on a machine with 1026 more than 1 Gigabyte total physical RAM, answer "off" here (default 1027 choice and suitable for most users). This will result in a "3GB/1GB" 1028 split: 3GB are mapped so that each process sees a 3GB virtual memory 1029 space and the remaining part of the 4GB virtual memory space is used 1030 by the kernel to permanently map as much physical memory as 1031 possible. 1032 1033 If the machine has between 1 and 4 Gigabytes physical RAM, then 1034 answer "4GB" here. 1035 1036 If more than 4 Gigabytes is used then answer "64GB" here. This 1037 selection turns Intel PAE (Physical Address Extension) mode on. 1038 PAE implements 3-level paging on IA32 processors. PAE is fully 1039 supported by Linux, PAE mode is implemented on all recent Intel 1040 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1041 then the kernel will not boot on CPUs that don't support PAE! 1042 1043 The actual amount of total physical memory will either be 1044 auto detected or can be forced by using a kernel command line option 1045 such as "mem=256M". (Try "man bootparam" or see the documentation of 1046 your boot loader (lilo or loadlin) about how to pass options to the 1047 kernel at boot time.) 1048 1049 If unsure, say "off". 1050 1051config HIGHMEM4G 1052 bool "4GB" 1053 depends on !X86_NUMAQ 1054 ---help--- 1055 Select this if you have a 32-bit processor and between 1 and 4 1056 gigabytes of physical RAM. 1057 1058config HIGHMEM64G 1059 bool "64GB" 1060 depends on !M386 && !M486 1061 select X86_PAE 1062 ---help--- 1063 Select this if you have a 32-bit processor and more than 4 1064 gigabytes of physical RAM. 1065 1066endchoice 1067 1068choice 1069 depends on EXPERIMENTAL 1070 prompt "Memory split" if EMBEDDED 1071 default VMSPLIT_3G 1072 depends on X86_32 1073 ---help--- 1074 Select the desired split between kernel and user memory. 1075 1076 If the address range available to the kernel is less than the 1077 physical memory installed, the remaining memory will be available 1078 as "high memory". Accessing high memory is a little more costly 1079 than low memory, as it needs to be mapped into the kernel first. 1080 Note that increasing the kernel address space limits the range 1081 available to user programs, making the address space there 1082 tighter. Selecting anything other than the default 3G/1G split 1083 will also likely make your kernel incompatible with binary-only 1084 kernel modules. 1085 1086 If you are not absolutely sure what you are doing, leave this 1087 option alone! 1088 1089 config VMSPLIT_3G 1090 bool "3G/1G user/kernel split" 1091 config VMSPLIT_3G_OPT 1092 depends on !X86_PAE 1093 bool "3G/1G user/kernel split (for full 1G low memory)" 1094 config VMSPLIT_2G 1095 bool "2G/2G user/kernel split" 1096 config VMSPLIT_2G_OPT 1097 depends on !X86_PAE 1098 bool "2G/2G user/kernel split (for full 2G low memory)" 1099 config VMSPLIT_1G 1100 bool "1G/3G user/kernel split" 1101endchoice 1102 1103config PAGE_OFFSET 1104 hex 1105 default 0xB0000000 if VMSPLIT_3G_OPT 1106 default 0x80000000 if VMSPLIT_2G 1107 default 0x78000000 if VMSPLIT_2G_OPT 1108 default 0x40000000 if VMSPLIT_1G 1109 default 0xC0000000 1110 depends on X86_32 1111 1112config HIGHMEM 1113 def_bool y 1114 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1115 1116config X86_PAE 1117 bool "PAE (Physical Address Extension) Support" 1118 depends on X86_32 && !HIGHMEM4G 1119 ---help--- 1120 PAE is required for NX support, and furthermore enables 1121 larger swapspace support for non-overcommit purposes. It 1122 has the cost of more pagetable lookup overhead, and also 1123 consumes more pagetable space per process. 1124 1125config ARCH_PHYS_ADDR_T_64BIT 1126 def_bool X86_64 || X86_PAE 1127 1128config DIRECT_GBPAGES 1129 bool "Enable 1GB pages for kernel pagetables" if EMBEDDED 1130 default y 1131 depends on X86_64 1132 ---help--- 1133 Allow the kernel linear mapping to use 1GB pages on CPUs that 1134 support it. This can improve the kernel's performance a tiny bit by 1135 reducing TLB pressure. If in doubt, say "Y". 1136 1137# Common NUMA Features 1138config NUMA 1139 bool "Numa Memory Allocation and Scheduler Support" 1140 depends on SMP 1141 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL) 1142 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP) 1143 ---help--- 1144 Enable NUMA (Non Uniform Memory Access) support. 1145 1146 The kernel will try to allocate memory used by a CPU on the 1147 local memory controller of the CPU and add some more 1148 NUMA awareness to the kernel. 1149 1150 For 64-bit this is recommended if the system is Intel Core i7 1151 (or later), AMD Opteron, or EM64T NUMA. 1152 1153 For 32-bit this is only needed on (rare) 32-bit-only platforms 1154 that support NUMA topologies, such as NUMAQ / Summit, or if you 1155 boot a 32-bit kernel on a 64-bit NUMA platform. 1156 1157 Otherwise, you should say N. 1158 1159comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 1160 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI) 1161 1162config K8_NUMA 1163 def_bool y 1164 prompt "Old style AMD Opteron NUMA detection" 1165 depends on X86_64 && NUMA && PCI 1166 ---help--- 1167 Enable K8 NUMA node topology detection. You should say Y here if 1168 you have a multi processor AMD K8 system. This uses an old 1169 method to read the NUMA configuration directly from the builtin 1170 Northbridge of Opteron. It is recommended to use X86_64_ACPI_NUMA 1171 instead, which also takes priority if both are compiled in. 1172 1173config X86_64_ACPI_NUMA 1174 def_bool y 1175 prompt "ACPI NUMA detection" 1176 depends on X86_64 && NUMA && ACPI && PCI 1177 select ACPI_NUMA 1178 ---help--- 1179 Enable ACPI SRAT based node topology detection. 1180 1181# Some NUMA nodes have memory ranges that span 1182# other nodes. Even though a pfn is valid and 1183# between a node's start and end pfns, it may not 1184# reside on that node. See memmap_init_zone() 1185# for details. 1186config NODES_SPAN_OTHER_NODES 1187 def_bool y 1188 depends on X86_64_ACPI_NUMA 1189 1190config NUMA_EMU 1191 bool "NUMA emulation" 1192 depends on X86_64 && NUMA 1193 ---help--- 1194 Enable NUMA emulation. A flat machine will be split 1195 into virtual nodes when booted with "numa=fake=N", where N is the 1196 number of nodes. This is only useful for debugging. 1197 1198config NODES_SHIFT 1199 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1200 range 1 9 1201 default "9" if MAXSMP 1202 default "6" if X86_64 1203 default "4" if X86_NUMAQ 1204 default "3" 1205 depends on NEED_MULTIPLE_NODES 1206 ---help--- 1207 Specify the maximum number of NUMA Nodes available on the target 1208 system. Increases memory reserved to accommodate various tables. 1209 1210config HAVE_ARCH_BOOTMEM 1211 def_bool y 1212 depends on X86_32 && NUMA 1213 1214config ARCH_HAVE_MEMORY_PRESENT 1215 def_bool y 1216 depends on X86_32 && DISCONTIGMEM 1217 1218config NEED_NODE_MEMMAP_SIZE 1219 def_bool y 1220 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1221 1222config HAVE_ARCH_ALLOC_REMAP 1223 def_bool y 1224 depends on X86_32 && NUMA 1225 1226config ARCH_FLATMEM_ENABLE 1227 def_bool y 1228 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA 1229 1230config ARCH_DISCONTIGMEM_ENABLE 1231 def_bool y 1232 depends on NUMA && X86_32 1233 1234config ARCH_DISCONTIGMEM_DEFAULT 1235 def_bool y 1236 depends on NUMA && X86_32 1237 1238config ARCH_SPARSEMEM_DEFAULT 1239 def_bool y 1240 depends on X86_64 1241 1242config ARCH_SPARSEMEM_ENABLE 1243 def_bool y 1244 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD 1245 select SPARSEMEM_STATIC if X86_32 1246 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1247 1248config ARCH_SELECT_MEMORY_MODEL 1249 def_bool y 1250 depends on ARCH_SPARSEMEM_ENABLE 1251 1252config ARCH_MEMORY_PROBE 1253 def_bool X86_64 1254 depends on MEMORY_HOTPLUG 1255 1256source "mm/Kconfig" 1257 1258config HIGHPTE 1259 bool "Allocate 3rd-level pagetables from highmem" 1260 depends on X86_32 && (HIGHMEM4G || HIGHMEM64G) 1261 ---help--- 1262 The VM uses one page table entry for each page of physical memory. 1263 For systems with a lot of RAM, this can be wasteful of precious 1264 low memory. Setting this option will put user-space page table 1265 entries in high memory. 1266 1267config X86_CHECK_BIOS_CORRUPTION 1268 bool "Check for low memory corruption" 1269 ---help--- 1270 Periodically check for memory corruption in low memory, which 1271 is suspected to be caused by BIOS. Even when enabled in the 1272 configuration, it is disabled at runtime. Enable it by 1273 setting "memory_corruption_check=1" on the kernel command 1274 line. By default it scans the low 64k of memory every 60 1275 seconds; see the memory_corruption_check_size and 1276 memory_corruption_check_period parameters in 1277 Documentation/kernel-parameters.txt to adjust this. 1278 1279 When enabled with the default parameters, this option has 1280 almost no overhead, as it reserves a relatively small amount 1281 of memory and scans it infrequently. It both detects corruption 1282 and prevents it from affecting the running system. 1283 1284 It is, however, intended as a diagnostic tool; if repeatable 1285 BIOS-originated corruption always affects the same memory, 1286 you can use memmap= to prevent the kernel from using that 1287 memory. 1288 1289config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1290 bool "Set the default setting of memory_corruption_check" 1291 depends on X86_CHECK_BIOS_CORRUPTION 1292 default y 1293 ---help--- 1294 Set whether the default state of memory_corruption_check is 1295 on or off. 1296 1297config X86_RESERVE_LOW_64K 1298 bool "Reserve low 64K of RAM on AMI/Phoenix BIOSen" 1299 default y 1300 ---help--- 1301 Reserve the first 64K of physical RAM on BIOSes that are known 1302 to potentially corrupt that memory range. A numbers of BIOSes are 1303 known to utilize this area during suspend/resume, so it must not 1304 be used by the kernel. 1305 1306 Set this to N if you are absolutely sure that you trust the BIOS 1307 to get all its memory reservations and usages right. 1308 1309 If you have doubts about the BIOS (e.g. suspend/resume does not 1310 work or there's kernel crashes after certain hardware hotplug 1311 events) and it's not AMI or Phoenix, then you might want to enable 1312 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check typical 1313 corruption patterns. 1314 1315 Say Y if unsure. 1316 1317config MATH_EMULATION 1318 bool 1319 prompt "Math emulation" if X86_32 1320 ---help--- 1321 Linux can emulate a math coprocessor (used for floating point 1322 operations) if you don't have one. 486DX and Pentium processors have 1323 a math coprocessor built in, 486SX and 386 do not, unless you added 1324 a 487DX or 387, respectively. (The messages during boot time can 1325 give you some hints here ["man dmesg"].) Everyone needs either a 1326 coprocessor or this emulation. 1327 1328 If you don't have a math coprocessor, you need to say Y here; if you 1329 say Y here even though you have a coprocessor, the coprocessor will 1330 be used nevertheless. (This behavior can be changed with the kernel 1331 command line option "no387", which comes handy if your coprocessor 1332 is broken. Try "man bootparam" or see the documentation of your boot 1333 loader (lilo or loadlin) about how to pass options to the kernel at 1334 boot time.) This means that it is a good idea to say Y here if you 1335 intend to use this kernel on different machines. 1336 1337 More information about the internals of the Linux math coprocessor 1338 emulation can be found in <file:arch/x86/math-emu/README>. 1339 1340 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1341 kernel, it won't hurt. 1342 1343config MTRR 1344 bool "MTRR (Memory Type Range Register) support" 1345 ---help--- 1346 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1347 the Memory Type Range Registers (MTRRs) may be used to control 1348 processor access to memory ranges. This is most useful if you have 1349 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1350 allows bus write transfers to be combined into a larger transfer 1351 before bursting over the PCI/AGP bus. This can increase performance 1352 of image write operations 2.5 times or more. Saying Y here creates a 1353 /proc/mtrr file which may be used to manipulate your processor's 1354 MTRRs. Typically the X server should use this. 1355 1356 This code has a reasonably generic interface so that similar 1357 control registers on other processors can be easily supported 1358 as well: 1359 1360 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1361 Registers (ARRs) which provide a similar functionality to MTRRs. For 1362 these, the ARRs are used to emulate the MTRRs. 1363 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1364 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1365 write-combining. All of these processors are supported by this code 1366 and it makes sense to say Y here if you have one of them. 1367 1368 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1369 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1370 can lead to all sorts of problems, so it's good to say Y here. 1371 1372 You can safely say Y even if your machine doesn't have MTRRs, you'll 1373 just add about 9 KB to your kernel. 1374 1375 See <file:Documentation/x86/mtrr.txt> for more information. 1376 1377config MTRR_SANITIZER 1378 def_bool y 1379 prompt "MTRR cleanup support" 1380 depends on MTRR 1381 ---help--- 1382 Convert MTRR layout from continuous to discrete, so X drivers can 1383 add writeback entries. 1384 1385 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1386 The largest mtrr entry size for a continuous block can be set with 1387 mtrr_chunk_size. 1388 1389 If unsure, say Y. 1390 1391config MTRR_SANITIZER_ENABLE_DEFAULT 1392 int "MTRR cleanup enable value (0-1)" 1393 range 0 1 1394 default "0" 1395 depends on MTRR_SANITIZER 1396 ---help--- 1397 Enable mtrr cleanup default value 1398 1399config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1400 int "MTRR cleanup spare reg num (0-7)" 1401 range 0 7 1402 default "1" 1403 depends on MTRR_SANITIZER 1404 ---help--- 1405 mtrr cleanup spare entries default, it can be changed via 1406 mtrr_spare_reg_nr=N on the kernel command line. 1407 1408config X86_PAT 1409 bool 1410 prompt "x86 PAT support" 1411 depends on MTRR 1412 ---help--- 1413 Use PAT attributes to setup page level cache control. 1414 1415 PATs are the modern equivalents of MTRRs and are much more 1416 flexible than MTRRs. 1417 1418 Say N here if you see bootup problems (boot crash, boot hang, 1419 spontaneous reboots) or a non-working video driver. 1420 1421 If unsure, say Y. 1422 1423config ARCH_USES_PG_UNCACHED 1424 def_bool y 1425 depends on X86_PAT 1426 1427config EFI 1428 bool "EFI runtime service support" 1429 depends on ACPI 1430 ---help--- 1431 This enables the kernel to use EFI runtime services that are 1432 available (such as the EFI variable services). 1433 1434 This option is only useful on systems that have EFI firmware. 1435 In addition, you should use the latest ELILO loader available 1436 at <http://elilo.sourceforge.net> in order to take advantage 1437 of EFI runtime services. However, even with this option, the 1438 resultant kernel should continue to boot on existing non-EFI 1439 platforms. 1440 1441config SECCOMP 1442 def_bool y 1443 prompt "Enable seccomp to safely compute untrusted bytecode" 1444 ---help--- 1445 This kernel feature is useful for number crunching applications 1446 that may need to compute untrusted bytecode during their 1447 execution. By using pipes or other transports made available to 1448 the process as file descriptors supporting the read/write 1449 syscalls, it's possible to isolate those applications in 1450 their own address space using seccomp. Once seccomp is 1451 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1452 and the task is only allowed to execute a few safe syscalls 1453 defined by each seccomp mode. 1454 1455 If unsure, say Y. Only embedded should say N here. 1456 1457config CC_STACKPROTECTOR_ALL 1458 bool 1459 1460config CC_STACKPROTECTOR 1461 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" 1462 select CC_STACKPROTECTOR_ALL 1463 ---help--- 1464 This option turns on the -fstack-protector GCC feature. This 1465 feature puts, at the beginning of functions, a canary value on 1466 the stack just before the return address, and validates 1467 the value just before actually returning. Stack based buffer 1468 overflows (that need to overwrite this return address) now also 1469 overwrite the canary, which gets detected and the attack is then 1470 neutralized via a kernel panic. 1471 1472 This feature requires gcc version 4.2 or above, or a distribution 1473 gcc with the feature backported. Older versions are automatically 1474 detected and for those versions, this configuration option is 1475 ignored. (and a warning is printed during bootup) 1476 1477source kernel/Kconfig.hz 1478 1479config KEXEC 1480 bool "kexec system call" 1481 ---help--- 1482 kexec is a system call that implements the ability to shutdown your 1483 current kernel, and to start another kernel. It is like a reboot 1484 but it is independent of the system firmware. And like a reboot 1485 you can start any kernel with it, not just Linux. 1486 1487 The name comes from the similarity to the exec system call. 1488 1489 It is an ongoing process to be certain the hardware in a machine 1490 is properly shutdown, so do not be surprised if this code does not 1491 initially work for you. It may help to enable device hotplugging 1492 support. As of this writing the exact hardware interface is 1493 strongly in flux, so no good recommendation can be made. 1494 1495config CRASH_DUMP 1496 bool "kernel crash dumps" 1497 depends on X86_64 || (X86_32 && HIGHMEM) 1498 ---help--- 1499 Generate crash dump after being started by kexec. 1500 This should be normally only set in special crash dump kernels 1501 which are loaded in the main kernel with kexec-tools into 1502 a specially reserved region and then later executed after 1503 a crash by kdump/kexec. The crash dump kernel must be compiled 1504 to a memory address not used by the main kernel or BIOS using 1505 PHYSICAL_START, or it must be built as a relocatable image 1506 (CONFIG_RELOCATABLE=y). 1507 For more details see Documentation/kdump/kdump.txt 1508 1509config KEXEC_JUMP 1510 bool "kexec jump (EXPERIMENTAL)" 1511 depends on EXPERIMENTAL 1512 depends on KEXEC && HIBERNATION 1513 ---help--- 1514 Jump between original kernel and kexeced kernel and invoke 1515 code in physical address mode via KEXEC 1516 1517config PHYSICAL_START 1518 hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) 1519 default "0x1000000" 1520 ---help--- 1521 This gives the physical address where the kernel is loaded. 1522 1523 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1524 bzImage will decompress itself to above physical address and 1525 run from there. Otherwise, bzImage will run from the address where 1526 it has been loaded by the boot loader and will ignore above physical 1527 address. 1528 1529 In normal kdump cases one does not have to set/change this option 1530 as now bzImage can be compiled as a completely relocatable image 1531 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1532 address. This option is mainly useful for the folks who don't want 1533 to use a bzImage for capturing the crash dump and want to use a 1534 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1535 to be specifically compiled to run from a specific memory area 1536 (normally a reserved region) and this option comes handy. 1537 1538 So if you are using bzImage for capturing the crash dump, 1539 leave the value here unchanged to 0x1000000 and set 1540 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1541 for capturing the crash dump change this value to start of 1542 the reserved region. In other words, it can be set based on 1543 the "X" value as specified in the "crashkernel=YM@XM" 1544 command line boot parameter passed to the panic-ed 1545 kernel. Please take a look at Documentation/kdump/kdump.txt 1546 for more details about crash dumps. 1547 1548 Usage of bzImage for capturing the crash dump is recommended as 1549 one does not have to build two kernels. Same kernel can be used 1550 as production kernel and capture kernel. Above option should have 1551 gone away after relocatable bzImage support is introduced. But it 1552 is present because there are users out there who continue to use 1553 vmlinux for dump capture. This option should go away down the 1554 line. 1555 1556 Don't change this unless you know what you are doing. 1557 1558config RELOCATABLE 1559 bool "Build a relocatable kernel" 1560 default y 1561 ---help--- 1562 This builds a kernel image that retains relocation information 1563 so it can be loaded someplace besides the default 1MB. 1564 The relocations tend to make the kernel binary about 10% larger, 1565 but are discarded at runtime. 1566 1567 One use is for the kexec on panic case where the recovery kernel 1568 must live at a different physical address than the primary 1569 kernel. 1570 1571 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1572 it has been loaded at and the compile time physical address 1573 (CONFIG_PHYSICAL_START) is ignored. 1574 1575# Relocation on x86-32 needs some additional build support 1576config X86_NEED_RELOCS 1577 def_bool y 1578 depends on X86_32 && RELOCATABLE 1579 1580config PHYSICAL_ALIGN 1581 hex 1582 prompt "Alignment value to which kernel should be aligned" if X86_32 1583 default "0x1000000" 1584 range 0x2000 0x1000000 1585 ---help--- 1586 This value puts the alignment restrictions on physical address 1587 where kernel is loaded and run from. Kernel is compiled for an 1588 address which meets above alignment restriction. 1589 1590 If bootloader loads the kernel at a non-aligned address and 1591 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1592 address aligned to above value and run from there. 1593 1594 If bootloader loads the kernel at a non-aligned address and 1595 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1596 load address and decompress itself to the address it has been 1597 compiled for and run from there. The address for which kernel is 1598 compiled already meets above alignment restrictions. Hence the 1599 end result is that kernel runs from a physical address meeting 1600 above alignment restrictions. 1601 1602 Don't change this unless you know what you are doing. 1603 1604config HOTPLUG_CPU 1605 bool "Support for hot-pluggable CPUs" 1606 depends on SMP && HOTPLUG 1607 ---help--- 1608 Say Y here to allow turning CPUs off and on. CPUs can be 1609 controlled through /sys/devices/system/cpu. 1610 ( Note: power management support will enable this option 1611 automatically on SMP systems. ) 1612 Say N if you want to disable CPU hotplug. 1613 1614config COMPAT_VDSO 1615 def_bool y 1616 prompt "Compat VDSO support" 1617 depends on X86_32 || IA32_EMULATION 1618 ---help--- 1619 Map the 32-bit VDSO to the predictable old-style address too. 1620 ---help--- 1621 Say N here if you are running a sufficiently recent glibc 1622 version (2.3.3 or later), to remove the high-mapped 1623 VDSO mapping and to exclusively use the randomized VDSO. 1624 1625 If unsure, say Y. 1626 1627config CMDLINE_BOOL 1628 bool "Built-in kernel command line" 1629 default n 1630 ---help--- 1631 Allow for specifying boot arguments to the kernel at 1632 build time. On some systems (e.g. embedded ones), it is 1633 necessary or convenient to provide some or all of the 1634 kernel boot arguments with the kernel itself (that is, 1635 to not rely on the boot loader to provide them.) 1636 1637 To compile command line arguments into the kernel, 1638 set this option to 'Y', then fill in the 1639 the boot arguments in CONFIG_CMDLINE. 1640 1641 Systems with fully functional boot loaders (i.e. non-embedded) 1642 should leave this option set to 'N'. 1643 1644config CMDLINE 1645 string "Built-in kernel command string" 1646 depends on CMDLINE_BOOL 1647 default "" 1648 ---help--- 1649 Enter arguments here that should be compiled into the kernel 1650 image and used at boot time. If the boot loader provides a 1651 command line at boot time, it is appended to this string to 1652 form the full kernel command line, when the system boots. 1653 1654 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1655 change this behavior. 1656 1657 In most cases, the command line (whether built-in or provided 1658 by the boot loader) should specify the device for the root 1659 file system. 1660 1661config CMDLINE_OVERRIDE 1662 bool "Built-in command line overrides boot loader arguments" 1663 default n 1664 depends on CMDLINE_BOOL 1665 ---help--- 1666 Set this option to 'Y' to have the kernel ignore the boot loader 1667 command line, and use ONLY the built-in command line. 1668 1669 This is used to work around broken boot loaders. This should 1670 be set to 'N' under normal conditions. 1671 1672endmenu 1673 1674config ARCH_ENABLE_MEMORY_HOTPLUG 1675 def_bool y 1676 depends on X86_64 || (X86_32 && HIGHMEM) 1677 1678config ARCH_ENABLE_MEMORY_HOTREMOVE 1679 def_bool y 1680 depends on MEMORY_HOTPLUG 1681 1682config HAVE_ARCH_EARLY_PFN_TO_NID 1683 def_bool X86_64 1684 depends on NUMA 1685 1686menu "Power management and ACPI options" 1687 1688config ARCH_HIBERNATION_HEADER 1689 def_bool y 1690 depends on X86_64 && HIBERNATION 1691 1692source "kernel/power/Kconfig" 1693 1694source "drivers/acpi/Kconfig" 1695 1696config X86_APM_BOOT 1697 bool 1698 default y 1699 depends on APM || APM_MODULE 1700 1701menuconfig APM 1702 tristate "APM (Advanced Power Management) BIOS support" 1703 depends on X86_32 && PM_SLEEP 1704 ---help--- 1705 APM is a BIOS specification for saving power using several different 1706 techniques. This is mostly useful for battery powered laptops with 1707 APM compliant BIOSes. If you say Y here, the system time will be 1708 reset after a RESUME operation, the /proc/apm device will provide 1709 battery status information, and user-space programs will receive 1710 notification of APM "events" (e.g. battery status change). 1711 1712 If you select "Y" here, you can disable actual use of the APM 1713 BIOS by passing the "apm=off" option to the kernel at boot time. 1714 1715 Note that the APM support is almost completely disabled for 1716 machines with more than one CPU. 1717 1718 In order to use APM, you will need supporting software. For location 1719 and more information, read <file:Documentation/power/pm.txt> and the 1720 Battery Powered Linux mini-HOWTO, available from 1721 <http://www.tldp.org/docs.html#howto>. 1722 1723 This driver does not spin down disk drives (see the hdparm(8) 1724 manpage ("man 8 hdparm") for that), and it doesn't turn off 1725 VESA-compliant "green" monitors. 1726 1727 This driver does not support the TI 4000M TravelMate and the ACER 1728 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1729 desktop machines also don't have compliant BIOSes, and this driver 1730 may cause those machines to panic during the boot phase. 1731 1732 Generally, if you don't have a battery in your machine, there isn't 1733 much point in using this driver and you should say N. If you get 1734 random kernel OOPSes or reboots that don't seem to be related to 1735 anything, try disabling/enabling this option (or disabling/enabling 1736 APM in your BIOS). 1737 1738 Some other things you should try when experiencing seemingly random, 1739 "weird" problems: 1740 1741 1) make sure that you have enough swap space and that it is 1742 enabled. 1743 2) pass the "no-hlt" option to the kernel 1744 3) switch on floating point emulation in the kernel and pass 1745 the "no387" option to the kernel 1746 4) pass the "floppy=nodma" option to the kernel 1747 5) pass the "mem=4M" option to the kernel (thereby disabling 1748 all but the first 4 MB of RAM) 1749 6) make sure that the CPU is not over clocked. 1750 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1751 8) disable the cache from your BIOS settings 1752 9) install a fan for the video card or exchange video RAM 1753 10) install a better fan for the CPU 1754 11) exchange RAM chips 1755 12) exchange the motherboard. 1756 1757 To compile this driver as a module, choose M here: the 1758 module will be called apm. 1759 1760if APM 1761 1762config APM_IGNORE_USER_SUSPEND 1763 bool "Ignore USER SUSPEND" 1764 ---help--- 1765 This option will ignore USER SUSPEND requests. On machines with a 1766 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1767 series notebooks, it is necessary to say Y because of a BIOS bug. 1768 1769config APM_DO_ENABLE 1770 bool "Enable PM at boot time" 1771 ---help--- 1772 Enable APM features at boot time. From page 36 of the APM BIOS 1773 specification: "When disabled, the APM BIOS does not automatically 1774 power manage devices, enter the Standby State, enter the Suspend 1775 State, or take power saving steps in response to CPU Idle calls." 1776 This driver will make CPU Idle calls when Linux is idle (unless this 1777 feature is turned off -- see "Do CPU IDLE calls", below). This 1778 should always save battery power, but more complicated APM features 1779 will be dependent on your BIOS implementation. You may need to turn 1780 this option off if your computer hangs at boot time when using APM 1781 support, or if it beeps continuously instead of suspending. Turn 1782 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1783 T400CDT. This is off by default since most machines do fine without 1784 this feature. 1785 1786config APM_CPU_IDLE 1787 bool "Make CPU Idle calls when idle" 1788 ---help--- 1789 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1790 On some machines, this can activate improved power savings, such as 1791 a slowed CPU clock rate, when the machine is idle. These idle calls 1792 are made after the idle loop has run for some length of time (e.g., 1793 333 mS). On some machines, this will cause a hang at boot time or 1794 whenever the CPU becomes idle. (On machines with more than one CPU, 1795 this option does nothing.) 1796 1797config APM_DISPLAY_BLANK 1798 bool "Enable console blanking using APM" 1799 ---help--- 1800 Enable console blanking using the APM. Some laptops can use this to 1801 turn off the LCD backlight when the screen blanker of the Linux 1802 virtual console blanks the screen. Note that this is only used by 1803 the virtual console screen blanker, and won't turn off the backlight 1804 when using the X Window system. This also doesn't have anything to 1805 do with your VESA-compliant power-saving monitor. Further, this 1806 option doesn't work for all laptops -- it might not turn off your 1807 backlight at all, or it might print a lot of errors to the console, 1808 especially if you are using gpm. 1809 1810config APM_ALLOW_INTS 1811 bool "Allow interrupts during APM BIOS calls" 1812 ---help--- 1813 Normally we disable external interrupts while we are making calls to 1814 the APM BIOS as a measure to lessen the effects of a badly behaving 1815 BIOS implementation. The BIOS should reenable interrupts if it 1816 needs to. Unfortunately, some BIOSes do not -- especially those in 1817 many of the newer IBM Thinkpads. If you experience hangs when you 1818 suspend, try setting this to Y. Otherwise, say N. 1819 1820endif # APM 1821 1822source "arch/x86/kernel/cpu/cpufreq/Kconfig" 1823 1824source "drivers/cpuidle/Kconfig" 1825 1826source "drivers/idle/Kconfig" 1827 1828endmenu 1829 1830 1831menu "Bus options (PCI etc.)" 1832 1833config PCI 1834 bool "PCI support" 1835 default y 1836 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC) 1837 ---help--- 1838 Find out whether you have a PCI motherboard. PCI is the name of a 1839 bus system, i.e. the way the CPU talks to the other stuff inside 1840 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 1841 VESA. If you have PCI, say Y, otherwise N. 1842 1843choice 1844 prompt "PCI access mode" 1845 depends on X86_32 && PCI 1846 default PCI_GOANY 1847 ---help--- 1848 On PCI systems, the BIOS can be used to detect the PCI devices and 1849 determine their configuration. However, some old PCI motherboards 1850 have BIOS bugs and may crash if this is done. Also, some embedded 1851 PCI-based systems don't have any BIOS at all. Linux can also try to 1852 detect the PCI hardware directly without using the BIOS. 1853 1854 With this option, you can specify how Linux should detect the 1855 PCI devices. If you choose "BIOS", the BIOS will be used, 1856 if you choose "Direct", the BIOS won't be used, and if you 1857 choose "MMConfig", then PCI Express MMCONFIG will be used. 1858 If you choose "Any", the kernel will try MMCONFIG, then the 1859 direct access method and falls back to the BIOS if that doesn't 1860 work. If unsure, go with the default, which is "Any". 1861 1862config PCI_GOBIOS 1863 bool "BIOS" 1864 1865config PCI_GOMMCONFIG 1866 bool "MMConfig" 1867 1868config PCI_GODIRECT 1869 bool "Direct" 1870 1871config PCI_GOOLPC 1872 bool "OLPC" 1873 depends on OLPC 1874 1875config PCI_GOANY 1876 bool "Any" 1877 1878endchoice 1879 1880config PCI_BIOS 1881 def_bool y 1882 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 1883 1884# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 1885config PCI_DIRECT 1886 def_bool y 1887 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC)) 1888 1889config PCI_MMCONFIG 1890 def_bool y 1891 depends on X86_32 && PCI && ACPI && (PCI_GOMMCONFIG || PCI_GOANY) 1892 1893config PCI_OLPC 1894 def_bool y 1895 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 1896 1897config PCI_DOMAINS 1898 def_bool y 1899 depends on PCI 1900 1901config PCI_MMCONFIG 1902 bool "Support mmconfig PCI config space access" 1903 depends on X86_64 && PCI && ACPI 1904 1905config DMAR 1906 bool "Support for DMA Remapping Devices (EXPERIMENTAL)" 1907 depends on PCI_MSI && ACPI && EXPERIMENTAL 1908 help 1909 DMA remapping (DMAR) devices support enables independent address 1910 translations for Direct Memory Access (DMA) from devices. 1911 These DMA remapping devices are reported via ACPI tables 1912 and include PCI device scope covered by these DMA 1913 remapping devices. 1914 1915config DMAR_DEFAULT_ON 1916 def_bool y 1917 prompt "Enable DMA Remapping Devices by default" 1918 depends on DMAR 1919 help 1920 Selecting this option will enable a DMAR device at boot time if 1921 one is found. If this option is not selected, DMAR support can 1922 be enabled by passing intel_iommu=on to the kernel. It is 1923 recommended you say N here while the DMAR code remains 1924 experimental. 1925 1926config DMAR_BROKEN_GFX_WA 1927 def_bool n 1928 prompt "Workaround broken graphics drivers (going away soon)" 1929 depends on DMAR 1930 ---help--- 1931 Current Graphics drivers tend to use physical address 1932 for DMA and avoid using DMA APIs. Setting this config 1933 option permits the IOMMU driver to set a unity map for 1934 all the OS-visible memory. Hence the driver can continue 1935 to use physical addresses for DMA, at least until this 1936 option is removed in the 2.6.32 kernel. 1937 1938config DMAR_FLOPPY_WA 1939 def_bool y 1940 depends on DMAR 1941 ---help--- 1942 Floppy disk drivers are known to bypass DMA API calls 1943 thereby failing to work when IOMMU is enabled. This 1944 workaround will setup a 1:1 mapping for the first 1945 16MiB to make floppy (an ISA device) work. 1946 1947config INTR_REMAP 1948 bool "Support for Interrupt Remapping (EXPERIMENTAL)" 1949 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL 1950 ---help--- 1951 Supports Interrupt remapping for IO-APIC and MSI devices. 1952 To use x2apic mode in the CPU's which support x2APIC enhancements or 1953 to support platforms with CPU's having > 8 bit APIC ID, say Y. 1954 1955source "drivers/pci/pcie/Kconfig" 1956 1957source "drivers/pci/Kconfig" 1958 1959# x86_64 have no ISA slots, but do have ISA-style DMA. 1960config ISA_DMA_API 1961 def_bool y 1962 1963if X86_32 1964 1965config ISA 1966 bool "ISA support" 1967 ---help--- 1968 Find out whether you have ISA slots on your motherboard. ISA is the 1969 name of a bus system, i.e. the way the CPU talks to the other stuff 1970 inside your box. Other bus systems are PCI, EISA, MicroChannel 1971 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 1972 newer boards don't support it. If you have ISA, say Y, otherwise N. 1973 1974config EISA 1975 bool "EISA support" 1976 depends on ISA 1977 ---help--- 1978 The Extended Industry Standard Architecture (EISA) bus was 1979 developed as an open alternative to the IBM MicroChannel bus. 1980 1981 The EISA bus provided some of the features of the IBM MicroChannel 1982 bus while maintaining backward compatibility with cards made for 1983 the older ISA bus. The EISA bus saw limited use between 1988 and 1984 1995 when it was made obsolete by the PCI bus. 1985 1986 Say Y here if you are building a kernel for an EISA-based machine. 1987 1988 Otherwise, say N. 1989 1990source "drivers/eisa/Kconfig" 1991 1992config MCA 1993 bool "MCA support" 1994 ---help--- 1995 MicroChannel Architecture is found in some IBM PS/2 machines and 1996 laptops. It is a bus system similar to PCI or ISA. See 1997 <file:Documentation/mca.txt> (and especially the web page given 1998 there) before attempting to build an MCA bus kernel. 1999 2000source "drivers/mca/Kconfig" 2001 2002config SCx200 2003 tristate "NatSemi SCx200 support" 2004 ---help--- 2005 This provides basic support for National Semiconductor's 2006 (now AMD's) Geode processors. The driver probes for the 2007 PCI-IDs of several on-chip devices, so its a good dependency 2008 for other scx200_* drivers. 2009 2010 If compiled as a module, the driver is named scx200. 2011 2012config SCx200HR_TIMER 2013 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2014 depends on SCx200 && GENERIC_TIME 2015 default y 2016 ---help--- 2017 This driver provides a clocksource built upon the on-chip 2018 27MHz high-resolution timer. Its also a workaround for 2019 NSC Geode SC-1100's buggy TSC, which loses time when the 2020 processor goes idle (as is done by the scheduler). The 2021 other workaround is idle=poll boot option. 2022 2023config GEODE_MFGPT_TIMER 2024 def_bool y 2025 prompt "Geode Multi-Function General Purpose Timer (MFGPT) events" 2026 depends on MGEODE_LX && GENERIC_TIME && GENERIC_CLOCKEVENTS 2027 ---help--- 2028 This driver provides a clock event source based on the MFGPT 2029 timer(s) in the CS5535 and CS5536 companion chip for the geode. 2030 MFGPTs have a better resolution and max interval than the 2031 generic PIT, and are suitable for use as high-res timers. 2032 2033config OLPC 2034 bool "One Laptop Per Child support" 2035 default n 2036 ---help--- 2037 Add support for detecting the unique features of the OLPC 2038 XO hardware. 2039 2040endif # X86_32 2041 2042config K8_NB 2043 def_bool y 2044 depends on AGP_AMD64 || (X86_64 && (GART_IOMMU || (PCI && NUMA))) 2045 2046source "drivers/pcmcia/Kconfig" 2047 2048source "drivers/pci/hotplug/Kconfig" 2049 2050endmenu 2051 2052 2053menu "Executable file formats / Emulations" 2054 2055source "fs/Kconfig.binfmt" 2056 2057config IA32_EMULATION 2058 bool "IA32 Emulation" 2059 depends on X86_64 2060 select COMPAT_BINFMT_ELF 2061 ---help--- 2062 Include code to run 32-bit programs under a 64-bit kernel. You should 2063 likely turn this on, unless you're 100% sure that you don't have any 2064 32-bit programs left. 2065 2066config IA32_AOUT 2067 tristate "IA32 a.out support" 2068 depends on IA32_EMULATION 2069 ---help--- 2070 Support old a.out binaries in the 32bit emulation. 2071 2072config COMPAT 2073 def_bool y 2074 depends on IA32_EMULATION 2075 2076config COMPAT_FOR_U64_ALIGNMENT 2077 def_bool COMPAT 2078 depends on X86_64 2079 2080config SYSVIPC_COMPAT 2081 def_bool y 2082 depends on COMPAT && SYSVIPC 2083 2084endmenu 2085 2086 2087config HAVE_ATOMIC_IOMAP 2088 def_bool y 2089 depends on X86_32 2090 2091source "net/Kconfig" 2092 2093source "drivers/Kconfig" 2094 2095source "drivers/firmware/Kconfig" 2096 2097source "fs/Kconfig" 2098 2099source "arch/x86/Kconfig.debug" 2100 2101source "security/Kconfig" 2102 2103source "crypto/Kconfig" 2104 2105source "arch/x86/kvm/Kconfig" 2106 2107source "lib/Kconfig" 2108