1# Select 32 or 64 bit 2config 64BIT 3 bool "64-bit kernel" if ARCH = "x86" 4 default ARCH = "x86_64" 5 ---help--- 6 Say yes to build a 64-bit kernel - formerly known as x86_64 7 Say no to build a 32-bit kernel - formerly known as i386 8 9config X86_32 10 def_bool !64BIT 11 12config X86_64 13 def_bool 64BIT 14 15### Arch settings 16config X86 17 def_bool y 18 select HAVE_AOUT if X86_32 19 select HAVE_READQ 20 select HAVE_WRITEQ 21 select HAVE_UNSTABLE_SCHED_CLOCK 22 select HAVE_IDE 23 select HAVE_OPROFILE 24 select HAVE_PERF_EVENTS 25 select HAVE_IRQ_WORK 26 select HAVE_IOREMAP_PROT 27 select HAVE_KPROBES 28 select HAVE_MEMBLOCK 29 select ARCH_WANT_OPTIONAL_GPIOLIB 30 select ARCH_WANT_FRAME_POINTERS 31 select HAVE_DMA_ATTRS 32 select HAVE_KRETPROBES 33 select HAVE_OPTPROBES 34 select HAVE_FTRACE_MCOUNT_RECORD 35 select HAVE_C_RECORDMCOUNT 36 select HAVE_DYNAMIC_FTRACE 37 select HAVE_FUNCTION_TRACER 38 select HAVE_FUNCTION_GRAPH_TRACER 39 select HAVE_FUNCTION_GRAPH_FP_TEST 40 select HAVE_FUNCTION_TRACE_MCOUNT_TEST 41 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE 42 select HAVE_SYSCALL_TRACEPOINTS 43 select HAVE_KVM 44 select HAVE_ARCH_KGDB 45 select HAVE_ARCH_TRACEHOOK 46 select HAVE_GENERIC_DMA_COHERENT if X86_32 47 select HAVE_EFFICIENT_UNALIGNED_ACCESS 48 select USER_STACKTRACE_SUPPORT 49 select HAVE_REGS_AND_STACK_ACCESS_API 50 select HAVE_DMA_API_DEBUG 51 select HAVE_KERNEL_GZIP 52 select HAVE_KERNEL_BZIP2 53 select HAVE_KERNEL_LZMA 54 select HAVE_KERNEL_XZ 55 select HAVE_KERNEL_LZO 56 select HAVE_HW_BREAKPOINT 57 select HAVE_MIXED_BREAKPOINTS_REGS 58 select PERF_EVENTS 59 select HAVE_PERF_EVENTS_NMI 60 select ANON_INODES 61 select HAVE_ARCH_KMEMCHECK 62 select HAVE_USER_RETURN_NOTIFIER 63 select HAVE_ARCH_JUMP_LABEL 64 select HAVE_TEXT_POKE_SMP 65 select HAVE_GENERIC_HARDIRQS 66 select HAVE_SPARSE_IRQ 67 select GENERIC_IRQ_PROBE 68 select GENERIC_PENDING_IRQ if SMP 69 select USE_GENERIC_SMP_HELPERS if SMP 70 71config INSTRUCTION_DECODER 72 def_bool (KPROBES || PERF_EVENTS) 73 74config OUTPUT_FORMAT 75 string 76 default "elf32-i386" if X86_32 77 default "elf64-x86-64" if X86_64 78 79config ARCH_DEFCONFIG 80 string 81 default "arch/x86/configs/i386_defconfig" if X86_32 82 default "arch/x86/configs/x86_64_defconfig" if X86_64 83 84config GENERIC_CMOS_UPDATE 85 def_bool y 86 87config CLOCKSOURCE_WATCHDOG 88 def_bool y 89 90config GENERIC_CLOCKEVENTS 91 def_bool y 92 93config GENERIC_CLOCKEVENTS_BROADCAST 94 def_bool y 95 depends on X86_64 || (X86_32 && X86_LOCAL_APIC) 96 97config LOCKDEP_SUPPORT 98 def_bool y 99 100config STACKTRACE_SUPPORT 101 def_bool y 102 103config HAVE_LATENCYTOP_SUPPORT 104 def_bool y 105 106config MMU 107 def_bool y 108 109config ZONE_DMA 110 def_bool y 111 112config SBUS 113 bool 114 115config NEED_DMA_MAP_STATE 116 def_bool (X86_64 || DMAR || DMA_API_DEBUG) 117 118config NEED_SG_DMA_LENGTH 119 def_bool y 120 121config GENERIC_ISA_DMA 122 def_bool y 123 124config GENERIC_IOMAP 125 def_bool y 126 127config GENERIC_BUG 128 def_bool y 129 depends on BUG 130 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 131 132config GENERIC_BUG_RELATIVE_POINTERS 133 bool 134 135config GENERIC_HWEIGHT 136 def_bool y 137 138config GENERIC_GPIO 139 bool 140 141config ARCH_MAY_HAVE_PC_FDC 142 def_bool y 143 144config RWSEM_GENERIC_SPINLOCK 145 def_bool !X86_XADD 146 147config RWSEM_XCHGADD_ALGORITHM 148 def_bool X86_XADD 149 150config ARCH_HAS_CPU_IDLE_WAIT 151 def_bool y 152 153config GENERIC_CALIBRATE_DELAY 154 def_bool y 155 156config GENERIC_TIME_VSYSCALL 157 bool 158 default X86_64 159 160config ARCH_HAS_CPU_RELAX 161 def_bool y 162 163config ARCH_HAS_DEFAULT_IDLE 164 def_bool y 165 166config ARCH_HAS_CACHE_LINE_SIZE 167 def_bool y 168 169config HAVE_SETUP_PER_CPU_AREA 170 def_bool y 171 172config NEED_PER_CPU_EMBED_FIRST_CHUNK 173 def_bool y 174 175config NEED_PER_CPU_PAGE_FIRST_CHUNK 176 def_bool y 177 178config HAVE_CPUMASK_OF_CPU_MAP 179 def_bool X86_64_SMP 180 181config ARCH_HIBERNATION_POSSIBLE 182 def_bool y 183 184config ARCH_SUSPEND_POSSIBLE 185 def_bool y 186 187config ZONE_DMA32 188 bool 189 default X86_64 190 191config ARCH_POPULATES_NODE_MAP 192 def_bool y 193 194config AUDIT_ARCH 195 bool 196 default X86_64 197 198config ARCH_SUPPORTS_OPTIMIZED_INLINING 199 def_bool y 200 201config ARCH_SUPPORTS_DEBUG_PAGEALLOC 202 def_bool y 203 204config HAVE_INTEL_TXT 205 def_bool y 206 depends on EXPERIMENTAL && DMAR && ACPI 207 208config X86_32_SMP 209 def_bool y 210 depends on X86_32 && SMP 211 212config X86_64_SMP 213 def_bool y 214 depends on X86_64 && SMP 215 216config X86_HT 217 def_bool y 218 depends on SMP 219 220config X86_TRAMPOLINE 221 def_bool y 222 depends on SMP || (64BIT && ACPI_SLEEP) 223 224config X86_32_LAZY_GS 225 def_bool y 226 depends on X86_32 && !CC_STACKPROTECTOR 227 228config ARCH_HWEIGHT_CFLAGS 229 string 230 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 231 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 232 233config KTIME_SCALAR 234 def_bool X86_32 235 236config ARCH_CPU_PROBE_RELEASE 237 def_bool y 238 depends on HOTPLUG_CPU 239 240source "init/Kconfig" 241source "kernel/Kconfig.freezer" 242 243menu "Processor type and features" 244 245source "kernel/time/Kconfig" 246 247config SMP 248 bool "Symmetric multi-processing support" 249 ---help--- 250 This enables support for systems with more than one CPU. If you have 251 a system with only one CPU, like most personal computers, say N. If 252 you have a system with more than one CPU, say Y. 253 254 If you say N here, the kernel will run on single and multiprocessor 255 machines, but will use only one CPU of a multiprocessor machine. If 256 you say Y here, the kernel will run on many, but not all, 257 singleprocessor machines. On a singleprocessor machine, the kernel 258 will run faster if you say N here. 259 260 Note that if you say Y here and choose architecture "586" or 261 "Pentium" under "Processor family", the kernel will not work on 486 262 architectures. Similarly, multiprocessor kernels for the "PPro" 263 architecture may not work on all Pentium based boards. 264 265 People using multiprocessor machines who say Y here should also say 266 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 267 Management" code will be disabled if you say Y here. 268 269 See also <file:Documentation/i386/IO-APIC.txt>, 270 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 271 <http://www.tldp.org/docs.html#howto>. 272 273 If you don't know what to do here, say N. 274 275config X86_X2APIC 276 bool "Support x2apic" 277 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP 278 ---help--- 279 This enables x2apic support on CPUs that have this feature. 280 281 This allows 32-bit apic IDs (so it can support very large systems), 282 and accesses the local apic via MSRs not via mmio. 283 284 If you don't know what to do here, say N. 285 286config X86_MPPARSE 287 bool "Enable MPS table" if ACPI 288 default y 289 depends on X86_LOCAL_APIC 290 ---help--- 291 For old smp systems that do not have proper acpi support. Newer systems 292 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 293 294config X86_BIGSMP 295 bool "Support for big SMP systems with more than 8 CPUs" 296 depends on X86_32 && SMP 297 ---help--- 298 This option is needed for the systems that have more than 8 CPUs 299 300if X86_32 301config X86_EXTENDED_PLATFORM 302 bool "Support for extended (non-PC) x86 platforms" 303 default y 304 ---help--- 305 If you disable this option then the kernel will only support 306 standard PC platforms. (which covers the vast majority of 307 systems out there.) 308 309 If you enable this option then you'll be able to select support 310 for the following (non-PC) 32 bit x86 platforms: 311 AMD Elan 312 NUMAQ (IBM/Sequent) 313 RDC R-321x SoC 314 SGI 320/540 (Visual Workstation) 315 Summit/EXA (IBM x440) 316 Unisys ES7000 IA32 series 317 Moorestown MID devices 318 319 If you have one of these systems, or if you want to build a 320 generic distribution kernel, say Y here - otherwise say N. 321endif 322 323if X86_64 324config X86_EXTENDED_PLATFORM 325 bool "Support for extended (non-PC) x86 platforms" 326 default y 327 ---help--- 328 If you disable this option then the kernel will only support 329 standard PC platforms. (which covers the vast majority of 330 systems out there.) 331 332 If you enable this option then you'll be able to select support 333 for the following (non-PC) 64 bit x86 platforms: 334 ScaleMP vSMP 335 SGI Ultraviolet 336 337 If you have one of these systems, or if you want to build a 338 generic distribution kernel, say Y here - otherwise say N. 339endif 340# This is an alphabetically sorted list of 64 bit extended platforms 341# Please maintain the alphabetic order if and when there are additions 342 343config X86_VSMP 344 bool "ScaleMP vSMP" 345 select PARAVIRT_GUEST 346 select PARAVIRT 347 depends on X86_64 && PCI 348 depends on X86_EXTENDED_PLATFORM 349 ---help--- 350 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 351 supposed to run on these EM64T-based machines. Only choose this option 352 if you have one of these machines. 353 354config X86_UV 355 bool "SGI Ultraviolet" 356 depends on X86_64 357 depends on X86_EXTENDED_PLATFORM 358 depends on NUMA 359 depends on X86_X2APIC 360 ---help--- 361 This option is needed in order to support SGI Ultraviolet systems. 362 If you don't have one of these, you should say N here. 363 364# Following is an alphabetically sorted list of 32 bit extended platforms 365# Please maintain the alphabetic order if and when there are additions 366 367config X86_ELAN 368 bool "AMD Elan" 369 depends on X86_32 370 depends on X86_EXTENDED_PLATFORM 371 ---help--- 372 Select this for an AMD Elan processor. 373 374 Do not use this option for K6/Athlon/Opteron processors! 375 376 If unsure, choose "PC-compatible" instead. 377 378config X86_INTEL_CE 379 bool "CE4100 TV platform" 380 depends on PCI 381 depends on PCI_GODIRECT 382 depends on X86_32 383 depends on X86_EXTENDED_PLATFORM 384 select X86_REBOOTFIXUPS 385 ---help--- 386 Select for the Intel CE media processor (CE4100) SOC. 387 This option compiles in support for the CE4100 SOC for settop 388 boxes and media devices. 389 390config X86_MRST 391 bool "Moorestown MID platform" 392 depends on PCI 393 depends on PCI_GOANY 394 depends on X86_32 395 depends on X86_EXTENDED_PLATFORM 396 depends on X86_IO_APIC 397 select APB_TIMER 398 select I2C 399 select SPI 400 select INTEL_SCU_IPC 401 select X86_PLATFORM_DEVICES 402 ---help--- 403 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin 404 Internet Device(MID) platform. Moorestown consists of two chips: 405 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH. 406 Unlike standard x86 PCs, Moorestown does not have many legacy devices 407 nor standard legacy replacement devices/features. e.g. Moorestown does 408 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports. 409 410config X86_RDC321X 411 bool "RDC R-321x SoC" 412 depends on X86_32 413 depends on X86_EXTENDED_PLATFORM 414 select M486 415 select X86_REBOOTFIXUPS 416 ---help--- 417 This option is needed for RDC R-321x system-on-chip, also known 418 as R-8610-(G). 419 If you don't have one of these chips, you should say N here. 420 421config X86_32_NON_STANDARD 422 bool "Support non-standard 32-bit SMP architectures" 423 depends on X86_32 && SMP 424 depends on X86_EXTENDED_PLATFORM 425 ---help--- 426 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default 427 subarchitectures. It is intended for a generic binary kernel. 428 if you select them all, kernel will probe it one by one. and will 429 fallback to default. 430 431# Alphabetically sorted list of Non standard 32 bit platforms 432 433config X86_NUMAQ 434 bool "NUMAQ (IBM/Sequent)" 435 depends on X86_32_NON_STANDARD 436 depends on PCI 437 select NUMA 438 select X86_MPPARSE 439 ---help--- 440 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent) 441 NUMA multiquad box. This changes the way that processors are 442 bootstrapped, and uses Clustered Logical APIC addressing mode instead 443 of Flat Logical. You will need a new lynxer.elf file to flash your 444 firmware with - send email to <Martin.Bligh@us.ibm.com>. 445 446config X86_SUPPORTS_MEMORY_FAILURE 447 def_bool y 448 # MCE code calls memory_failure(): 449 depends on X86_MCE 450 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 451 depends on !X86_NUMAQ 452 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 453 depends on X86_64 || !SPARSEMEM 454 select ARCH_SUPPORTS_MEMORY_FAILURE 455 456config X86_VISWS 457 bool "SGI 320/540 (Visual Workstation)" 458 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT 459 depends on X86_32_NON_STANDARD 460 ---help--- 461 The SGI Visual Workstation series is an IA32-based workstation 462 based on SGI systems chips with some legacy PC hardware attached. 463 464 Say Y here to create a kernel to run on the SGI 320 or 540. 465 466 A kernel compiled for the Visual Workstation will run on general 467 PCs as well. See <file:Documentation/sgi-visws.txt> for details. 468 469config X86_SUMMIT 470 bool "Summit/EXA (IBM x440)" 471 depends on X86_32_NON_STANDARD 472 ---help--- 473 This option is needed for IBM systems that use the Summit/EXA chipset. 474 In particular, it is needed for the x440. 475 476config X86_ES7000 477 bool "Unisys ES7000 IA32 series" 478 depends on X86_32_NON_STANDARD && X86_BIGSMP 479 ---help--- 480 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 481 supposed to run on an IA32-based Unisys ES7000 system. 482 483config X86_32_IRIS 484 tristate "Eurobraille/Iris poweroff module" 485 depends on X86_32 486 ---help--- 487 The Iris machines from EuroBraille do not have APM or ACPI support 488 to shut themselves down properly. A special I/O sequence is 489 needed to do so, which is what this module does at 490 kernel shutdown. 491 492 This is only for Iris machines from EuroBraille. 493 494 If unused, say N. 495 496config SCHED_OMIT_FRAME_POINTER 497 def_bool y 498 prompt "Single-depth WCHAN output" 499 depends on X86 500 ---help--- 501 Calculate simpler /proc/<PID>/wchan values. If this option 502 is disabled then wchan values will recurse back to the 503 caller function. This provides more accurate wchan values, 504 at the expense of slightly more scheduling overhead. 505 506 If in doubt, say "Y". 507 508menuconfig PARAVIRT_GUEST 509 bool "Paravirtualized guest support" 510 ---help--- 511 Say Y here to get to see options related to running Linux under 512 various hypervisors. This option alone does not add any kernel code. 513 514 If you say N, all options in this submenu will be skipped and disabled. 515 516if PARAVIRT_GUEST 517 518source "arch/x86/xen/Kconfig" 519 520config KVM_CLOCK 521 bool "KVM paravirtualized clock" 522 select PARAVIRT 523 select PARAVIRT_CLOCK 524 ---help--- 525 Turning on this option will allow you to run a paravirtualized clock 526 when running over the KVM hypervisor. Instead of relying on a PIT 527 (or probably other) emulation by the underlying device model, the host 528 provides the guest with timing infrastructure such as time of day, and 529 system time 530 531config KVM_GUEST 532 bool "KVM Guest support" 533 select PARAVIRT 534 ---help--- 535 This option enables various optimizations for running under the KVM 536 hypervisor. 537 538source "arch/x86/lguest/Kconfig" 539 540config PARAVIRT 541 bool "Enable paravirtualization code" 542 ---help--- 543 This changes the kernel so it can modify itself when it is run 544 under a hypervisor, potentially improving performance significantly 545 over full virtualization. However, when run without a hypervisor 546 the kernel is theoretically slower and slightly larger. 547 548config PARAVIRT_SPINLOCKS 549 bool "Paravirtualization layer for spinlocks" 550 depends on PARAVIRT && SMP && EXPERIMENTAL 551 ---help--- 552 Paravirtualized spinlocks allow a pvops backend to replace the 553 spinlock implementation with something virtualization-friendly 554 (for example, block the virtual CPU rather than spinning). 555 556 Unfortunately the downside is an up to 5% performance hit on 557 native kernels, with various workloads. 558 559 If you are unsure how to answer this question, answer N. 560 561config PARAVIRT_CLOCK 562 bool 563 564endif 565 566config PARAVIRT_DEBUG 567 bool "paravirt-ops debugging" 568 depends on PARAVIRT && DEBUG_KERNEL 569 ---help--- 570 Enable to debug paravirt_ops internals. Specifically, BUG if 571 a paravirt_op is missing when it is called. 572 573config NO_BOOTMEM 574 def_bool y 575 576config MEMTEST 577 bool "Memtest" 578 ---help--- 579 This option adds a kernel parameter 'memtest', which allows memtest 580 to be set. 581 memtest=0, mean disabled; -- default 582 memtest=1, mean do 1 test pattern; 583 ... 584 memtest=4, mean do 4 test patterns. 585 If you are unsure how to answer this question, answer N. 586 587config X86_SUMMIT_NUMA 588 def_bool y 589 depends on X86_32 && NUMA && X86_32_NON_STANDARD 590 591config X86_CYCLONE_TIMER 592 def_bool y 593 depends on X86_32_NON_STANDARD 594 595source "arch/x86/Kconfig.cpu" 596 597config HPET_TIMER 598 def_bool X86_64 599 prompt "HPET Timer Support" if X86_32 600 ---help--- 601 Use the IA-PC HPET (High Precision Event Timer) to manage 602 time in preference to the PIT and RTC, if a HPET is 603 present. 604 HPET is the next generation timer replacing legacy 8254s. 605 The HPET provides a stable time base on SMP 606 systems, unlike the TSC, but it is more expensive to access, 607 as it is off-chip. You can find the HPET spec at 608 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 609 610 You can safely choose Y here. However, HPET will only be 611 activated if the platform and the BIOS support this feature. 612 Otherwise the 8254 will be used for timing services. 613 614 Choose N to continue using the legacy 8254 timer. 615 616config HPET_EMULATE_RTC 617 def_bool y 618 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 619 620config APB_TIMER 621 def_bool y if MRST 622 prompt "Langwell APB Timer Support" if X86_MRST 623 help 624 APB timer is the replacement for 8254, HPET on X86 MID platforms. 625 The APBT provides a stable time base on SMP 626 systems, unlike the TSC, but it is more expensive to access, 627 as it is off-chip. APB timers are always running regardless of CPU 628 C states, they are used as per CPU clockevent device when possible. 629 630# Mark as expert because too many people got it wrong. 631# The code disables itself when not needed. 632config DMI 633 default y 634 bool "Enable DMI scanning" if EXPERT 635 ---help--- 636 Enabled scanning of DMI to identify machine quirks. Say Y 637 here unless you have verified that your setup is not 638 affected by entries in the DMI blacklist. Required by PNP 639 BIOS code. 640 641config GART_IOMMU 642 bool "GART IOMMU support" if EXPERT 643 default y 644 select SWIOTLB 645 depends on X86_64 && PCI && AMD_NB 646 ---help--- 647 Support for full DMA access of devices with 32bit memory access only 648 on systems with more than 3GB. This is usually needed for USB, 649 sound, many IDE/SATA chipsets and some other devices. 650 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART 651 based hardware IOMMU and a software bounce buffer based IOMMU used 652 on Intel systems and as fallback. 653 The code is only active when needed (enough memory and limited 654 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified 655 too. 656 657config CALGARY_IOMMU 658 bool "IBM Calgary IOMMU support" 659 select SWIOTLB 660 depends on X86_64 && PCI && EXPERIMENTAL 661 ---help--- 662 Support for hardware IOMMUs in IBM's xSeries x366 and x460 663 systems. Needed to run systems with more than 3GB of memory 664 properly with 32-bit PCI devices that do not support DAC 665 (Double Address Cycle). Calgary also supports bus level 666 isolation, where all DMAs pass through the IOMMU. This 667 prevents them from going anywhere except their intended 668 destination. This catches hard-to-find kernel bugs and 669 mis-behaving drivers and devices that do not use the DMA-API 670 properly to set up their DMA buffers. The IOMMU can be 671 turned off at boot time with the iommu=off parameter. 672 Normally the kernel will make the right choice by itself. 673 If unsure, say Y. 674 675config CALGARY_IOMMU_ENABLED_BY_DEFAULT 676 def_bool y 677 prompt "Should Calgary be enabled by default?" 678 depends on CALGARY_IOMMU 679 ---help--- 680 Should Calgary be enabled by default? if you choose 'y', Calgary 681 will be used (if it exists). If you choose 'n', Calgary will not be 682 used even if it exists. If you choose 'n' and would like to use 683 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 684 If unsure, say Y. 685 686config AMD_IOMMU 687 bool "AMD IOMMU support" 688 select SWIOTLB 689 select PCI_MSI 690 depends on X86_64 && PCI && ACPI 691 ---help--- 692 With this option you can enable support for AMD IOMMU hardware in 693 your system. An IOMMU is a hardware component which provides 694 remapping of DMA memory accesses from devices. With an AMD IOMMU you 695 can isolate the the DMA memory of different devices and protect the 696 system from misbehaving device drivers or hardware. 697 698 You can find out if your system has an AMD IOMMU if you look into 699 your BIOS for an option to enable it or if you have an IVRS ACPI 700 table. 701 702config AMD_IOMMU_STATS 703 bool "Export AMD IOMMU statistics to debugfs" 704 depends on AMD_IOMMU 705 select DEBUG_FS 706 ---help--- 707 This option enables code in the AMD IOMMU driver to collect various 708 statistics about whats happening in the driver and exports that 709 information to userspace via debugfs. 710 If unsure, say N. 711 712# need this always selected by IOMMU for the VIA workaround 713config SWIOTLB 714 def_bool y if X86_64 715 ---help--- 716 Support for software bounce buffers used on x86-64 systems 717 which don't have a hardware IOMMU (e.g. the current generation 718 of Intel's x86-64 CPUs). Using this PCI devices which can only 719 access 32-bits of memory can be used on systems with more than 720 3 GB of memory. If unsure, say Y. 721 722config IOMMU_HELPER 723 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU) 724 725config IOMMU_API 726 def_bool (AMD_IOMMU || DMAR) 727 728config MAXSMP 729 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 730 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL 731 select CPUMASK_OFFSTACK 732 ---help--- 733 Enable maximum number of CPUS and NUMA Nodes for this architecture. 734 If unsure, say N. 735 736config NR_CPUS 737 int "Maximum number of CPUs" if SMP && !MAXSMP 738 range 2 8 if SMP && X86_32 && !X86_BIGSMP 739 range 2 512 if SMP && !MAXSMP 740 default "1" if !SMP 741 default "4096" if MAXSMP 742 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000) 743 default "8" if SMP 744 ---help--- 745 This allows you to specify the maximum number of CPUs which this 746 kernel will support. The maximum supported value is 512 and the 747 minimum value which makes sense is 2. 748 749 This is purely to save memory - each supported CPU adds 750 approximately eight kilobytes to the kernel image. 751 752config SCHED_SMT 753 bool "SMT (Hyperthreading) scheduler support" 754 depends on X86_HT 755 ---help--- 756 SMT scheduler support improves the CPU scheduler's decision making 757 when dealing with Intel Pentium 4 chips with HyperThreading at a 758 cost of slightly increased overhead in some places. If unsure say 759 N here. 760 761config SCHED_MC 762 def_bool y 763 prompt "Multi-core scheduler support" 764 depends on X86_HT 765 ---help--- 766 Multi-core scheduler support improves the CPU scheduler's decision 767 making when dealing with multi-core CPU chips at a cost of slightly 768 increased overhead in some places. If unsure say N here. 769 770config IRQ_TIME_ACCOUNTING 771 bool "Fine granularity task level IRQ time accounting" 772 default n 773 ---help--- 774 Select this option to enable fine granularity task irq time 775 accounting. This is done by reading a timestamp on each 776 transitions between softirq and hardirq state, so there can be a 777 small performance impact. 778 779 If in doubt, say N here. 780 781source "kernel/Kconfig.preempt" 782 783config X86_UP_APIC 784 bool "Local APIC support on uniprocessors" 785 depends on X86_32 && !SMP && !X86_32_NON_STANDARD 786 ---help--- 787 A local APIC (Advanced Programmable Interrupt Controller) is an 788 integrated interrupt controller in the CPU. If you have a single-CPU 789 system which has a processor with a local APIC, you can say Y here to 790 enable and use it. If you say Y here even though your machine doesn't 791 have a local APIC, then the kernel will still run with no slowdown at 792 all. The local APIC supports CPU-generated self-interrupts (timer, 793 performance counters), and the NMI watchdog which detects hard 794 lockups. 795 796config X86_UP_IOAPIC 797 bool "IO-APIC support on uniprocessors" 798 depends on X86_UP_APIC 799 ---help--- 800 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 801 SMP-capable replacement for PC-style interrupt controllers. Most 802 SMP systems and many recent uniprocessor systems have one. 803 804 If you have a single-CPU system with an IO-APIC, you can say Y here 805 to use it. If you say Y here even though your machine doesn't have 806 an IO-APIC, then the kernel will still run with no slowdown at all. 807 808config X86_LOCAL_APIC 809 def_bool y 810 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC 811 812config X86_IO_APIC 813 def_bool y 814 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC 815 816config X86_VISWS_APIC 817 def_bool y 818 depends on X86_32 && X86_VISWS 819 820config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 821 bool "Reroute for broken boot IRQs" 822 depends on X86_IO_APIC 823 ---help--- 824 This option enables a workaround that fixes a source of 825 spurious interrupts. This is recommended when threaded 826 interrupt handling is used on systems where the generation of 827 superfluous "boot interrupts" cannot be disabled. 828 829 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 830 entry in the chipset's IO-APIC is masked (as, e.g. the RT 831 kernel does during interrupt handling). On chipsets where this 832 boot IRQ generation cannot be disabled, this workaround keeps 833 the original IRQ line masked so that only the equivalent "boot 834 IRQ" is delivered to the CPUs. The workaround also tells the 835 kernel to set up the IRQ handler on the boot IRQ line. In this 836 way only one interrupt is delivered to the kernel. Otherwise 837 the spurious second interrupt may cause the kernel to bring 838 down (vital) interrupt lines. 839 840 Only affects "broken" chipsets. Interrupt sharing may be 841 increased on these systems. 842 843config X86_MCE 844 bool "Machine Check / overheating reporting" 845 ---help--- 846 Machine Check support allows the processor to notify the 847 kernel if it detects a problem (e.g. overheating, data corruption). 848 The action the kernel takes depends on the severity of the problem, 849 ranging from warning messages to halting the machine. 850 851config X86_MCE_INTEL 852 def_bool y 853 prompt "Intel MCE features" 854 depends on X86_MCE && X86_LOCAL_APIC 855 ---help--- 856 Additional support for intel specific MCE features such as 857 the thermal monitor. 858 859config X86_MCE_AMD 860 def_bool y 861 prompt "AMD MCE features" 862 depends on X86_MCE && X86_LOCAL_APIC 863 ---help--- 864 Additional support for AMD specific MCE features such as 865 the DRAM Error Threshold. 866 867config X86_ANCIENT_MCE 868 bool "Support for old Pentium 5 / WinChip machine checks" 869 depends on X86_32 && X86_MCE 870 ---help--- 871 Include support for machine check handling on old Pentium 5 or WinChip 872 systems. These typically need to be enabled explicitely on the command 873 line. 874 875config X86_MCE_THRESHOLD 876 depends on X86_MCE_AMD || X86_MCE_INTEL 877 def_bool y 878 879config X86_MCE_INJECT 880 depends on X86_MCE 881 tristate "Machine check injector support" 882 ---help--- 883 Provide support for injecting machine checks for testing purposes. 884 If you don't know what a machine check is and you don't do kernel 885 QA it is safe to say n. 886 887config X86_THERMAL_VECTOR 888 def_bool y 889 depends on X86_MCE_INTEL 890 891config VM86 892 bool "Enable VM86 support" if EXPERT 893 default y 894 depends on X86_32 895 ---help--- 896 This option is required by programs like DOSEMU to run 16-bit legacy 897 code on X86 processors. It also may be needed by software like 898 XFree86 to initialize some video cards via BIOS. Disabling this 899 option saves about 6k. 900 901config TOSHIBA 902 tristate "Toshiba Laptop support" 903 depends on X86_32 904 ---help--- 905 This adds a driver to safely access the System Management Mode of 906 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 907 not work on models with a Phoenix BIOS. The System Management Mode 908 is used to set the BIOS and power saving options on Toshiba portables. 909 910 For information on utilities to make use of this driver see the 911 Toshiba Linux utilities web site at: 912 <http://www.buzzard.org.uk/toshiba/>. 913 914 Say Y if you intend to run this kernel on a Toshiba portable. 915 Say N otherwise. 916 917config I8K 918 tristate "Dell laptop support" 919 ---help--- 920 This adds a driver to safely access the System Management Mode 921 of the CPU on the Dell Inspiron 8000. The System Management Mode 922 is used to read cpu temperature and cooling fan status and to 923 control the fans on the I8K portables. 924 925 This driver has been tested only on the Inspiron 8000 but it may 926 also work with other Dell laptops. You can force loading on other 927 models by passing the parameter `force=1' to the module. Use at 928 your own risk. 929 930 For information on utilities to make use of this driver see the 931 I8K Linux utilities web site at: 932 <http://people.debian.org/~dz/i8k/> 933 934 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 935 Say N otherwise. 936 937config X86_REBOOTFIXUPS 938 bool "Enable X86 board specific fixups for reboot" 939 depends on X86_32 940 ---help--- 941 This enables chipset and/or board specific fixups to be done 942 in order to get reboot to work correctly. This is only needed on 943 some combinations of hardware and BIOS. The symptom, for which 944 this config is intended, is when reboot ends with a stalled/hung 945 system. 946 947 Currently, the only fixup is for the Geode machines using 948 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 949 950 Say Y if you want to enable the fixup. Currently, it's safe to 951 enable this option even if you don't need it. 952 Say N otherwise. 953 954config MICROCODE 955 tristate "/dev/cpu/microcode - microcode support" 956 select FW_LOADER 957 ---help--- 958 If you say Y here, you will be able to update the microcode on 959 certain Intel and AMD processors. The Intel support is for the 960 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, 961 Pentium 4, Xeon etc. The AMD support is for family 0x10 and 962 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra. 963 You will obviously need the actual microcode binary data itself 964 which is not shipped with the Linux kernel. 965 966 This option selects the general module only, you need to select 967 at least one vendor specific module as well. 968 969 To compile this driver as a module, choose M here: the 970 module will be called microcode. 971 972config MICROCODE_INTEL 973 bool "Intel microcode patch loading support" 974 depends on MICROCODE 975 default MICROCODE 976 select FW_LOADER 977 ---help--- 978 This options enables microcode patch loading support for Intel 979 processors. 980 981 For latest news and information on obtaining all the required 982 Intel ingredients for this driver, check: 983 <http://www.urbanmyth.org/microcode/>. 984 985config MICROCODE_AMD 986 bool "AMD microcode patch loading support" 987 depends on MICROCODE 988 select FW_LOADER 989 ---help--- 990 If you select this option, microcode patch loading support for AMD 991 processors will be enabled. 992 993config MICROCODE_OLD_INTERFACE 994 def_bool y 995 depends on MICROCODE 996 997config X86_MSR 998 tristate "/dev/cpu/*/msr - Model-specific register support" 999 ---help--- 1000 This device gives privileged processes access to the x86 1001 Model-Specific Registers (MSRs). It is a character device with 1002 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1003 MSR accesses are directed to a specific CPU on multi-processor 1004 systems. 1005 1006config X86_CPUID 1007 tristate "/dev/cpu/*/cpuid - CPU information support" 1008 ---help--- 1009 This device gives processes access to the x86 CPUID instruction to 1010 be executed on a specific processor. It is a character device 1011 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1012 /dev/cpu/31/cpuid. 1013 1014choice 1015 prompt "High Memory Support" 1016 default HIGHMEM64G if X86_NUMAQ 1017 default HIGHMEM4G 1018 depends on X86_32 1019 1020config NOHIGHMEM 1021 bool "off" 1022 depends on !X86_NUMAQ 1023 ---help--- 1024 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1025 However, the address space of 32-bit x86 processors is only 4 1026 Gigabytes large. That means that, if you have a large amount of 1027 physical memory, not all of it can be "permanently mapped" by the 1028 kernel. The physical memory that's not permanently mapped is called 1029 "high memory". 1030 1031 If you are compiling a kernel which will never run on a machine with 1032 more than 1 Gigabyte total physical RAM, answer "off" here (default 1033 choice and suitable for most users). This will result in a "3GB/1GB" 1034 split: 3GB are mapped so that each process sees a 3GB virtual memory 1035 space and the remaining part of the 4GB virtual memory space is used 1036 by the kernel to permanently map as much physical memory as 1037 possible. 1038 1039 If the machine has between 1 and 4 Gigabytes physical RAM, then 1040 answer "4GB" here. 1041 1042 If more than 4 Gigabytes is used then answer "64GB" here. This 1043 selection turns Intel PAE (Physical Address Extension) mode on. 1044 PAE implements 3-level paging on IA32 processors. PAE is fully 1045 supported by Linux, PAE mode is implemented on all recent Intel 1046 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1047 then the kernel will not boot on CPUs that don't support PAE! 1048 1049 The actual amount of total physical memory will either be 1050 auto detected or can be forced by using a kernel command line option 1051 such as "mem=256M". (Try "man bootparam" or see the documentation of 1052 your boot loader (lilo or loadlin) about how to pass options to the 1053 kernel at boot time.) 1054 1055 If unsure, say "off". 1056 1057config HIGHMEM4G 1058 bool "4GB" 1059 depends on !X86_NUMAQ 1060 ---help--- 1061 Select this if you have a 32-bit processor and between 1 and 4 1062 gigabytes of physical RAM. 1063 1064config HIGHMEM64G 1065 bool "64GB" 1066 depends on !M386 && !M486 1067 select X86_PAE 1068 ---help--- 1069 Select this if you have a 32-bit processor and more than 4 1070 gigabytes of physical RAM. 1071 1072endchoice 1073 1074choice 1075 depends on EXPERIMENTAL 1076 prompt "Memory split" if EXPERT 1077 default VMSPLIT_3G 1078 depends on X86_32 1079 ---help--- 1080 Select the desired split between kernel and user memory. 1081 1082 If the address range available to the kernel is less than the 1083 physical memory installed, the remaining memory will be available 1084 as "high memory". Accessing high memory is a little more costly 1085 than low memory, as it needs to be mapped into the kernel first. 1086 Note that increasing the kernel address space limits the range 1087 available to user programs, making the address space there 1088 tighter. Selecting anything other than the default 3G/1G split 1089 will also likely make your kernel incompatible with binary-only 1090 kernel modules. 1091 1092 If you are not absolutely sure what you are doing, leave this 1093 option alone! 1094 1095 config VMSPLIT_3G 1096 bool "3G/1G user/kernel split" 1097 config VMSPLIT_3G_OPT 1098 depends on !X86_PAE 1099 bool "3G/1G user/kernel split (for full 1G low memory)" 1100 config VMSPLIT_2G 1101 bool "2G/2G user/kernel split" 1102 config VMSPLIT_2G_OPT 1103 depends on !X86_PAE 1104 bool "2G/2G user/kernel split (for full 2G low memory)" 1105 config VMSPLIT_1G 1106 bool "1G/3G user/kernel split" 1107endchoice 1108 1109config PAGE_OFFSET 1110 hex 1111 default 0xB0000000 if VMSPLIT_3G_OPT 1112 default 0x80000000 if VMSPLIT_2G 1113 default 0x78000000 if VMSPLIT_2G_OPT 1114 default 0x40000000 if VMSPLIT_1G 1115 default 0xC0000000 1116 depends on X86_32 1117 1118config HIGHMEM 1119 def_bool y 1120 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1121 1122config X86_PAE 1123 bool "PAE (Physical Address Extension) Support" 1124 depends on X86_32 && !HIGHMEM4G 1125 ---help--- 1126 PAE is required for NX support, and furthermore enables 1127 larger swapspace support for non-overcommit purposes. It 1128 has the cost of more pagetable lookup overhead, and also 1129 consumes more pagetable space per process. 1130 1131config ARCH_PHYS_ADDR_T_64BIT 1132 def_bool X86_64 || X86_PAE 1133 1134config ARCH_DMA_ADDR_T_64BIT 1135 def_bool X86_64 || HIGHMEM64G 1136 1137config DIRECT_GBPAGES 1138 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1139 default y 1140 depends on X86_64 1141 ---help--- 1142 Allow the kernel linear mapping to use 1GB pages on CPUs that 1143 support it. This can improve the kernel's performance a tiny bit by 1144 reducing TLB pressure. If in doubt, say "Y". 1145 1146# Common NUMA Features 1147config NUMA 1148 bool "Numa Memory Allocation and Scheduler Support" 1149 depends on SMP 1150 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL) 1151 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP) 1152 ---help--- 1153 Enable NUMA (Non Uniform Memory Access) support. 1154 1155 The kernel will try to allocate memory used by a CPU on the 1156 local memory controller of the CPU and add some more 1157 NUMA awareness to the kernel. 1158 1159 For 64-bit this is recommended if the system is Intel Core i7 1160 (or later), AMD Opteron, or EM64T NUMA. 1161 1162 For 32-bit this is only needed on (rare) 32-bit-only platforms 1163 that support NUMA topologies, such as NUMAQ / Summit, or if you 1164 boot a 32-bit kernel on a 64-bit NUMA platform. 1165 1166 Otherwise, you should say N. 1167 1168comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 1169 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI) 1170 1171config AMD_NUMA 1172 def_bool y 1173 prompt "Old style AMD Opteron NUMA detection" 1174 depends on X86_64 && NUMA && PCI 1175 ---help--- 1176 Enable AMD NUMA node topology detection. You should say Y here if 1177 you have a multi processor AMD system. This uses an old method to 1178 read the NUMA configuration directly from the builtin Northbridge 1179 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1180 which also takes priority if both are compiled in. 1181 1182config X86_64_ACPI_NUMA 1183 def_bool y 1184 prompt "ACPI NUMA detection" 1185 depends on X86_64 && NUMA && ACPI && PCI 1186 select ACPI_NUMA 1187 ---help--- 1188 Enable ACPI SRAT based node topology detection. 1189 1190# Some NUMA nodes have memory ranges that span 1191# other nodes. Even though a pfn is valid and 1192# between a node's start and end pfns, it may not 1193# reside on that node. See memmap_init_zone() 1194# for details. 1195config NODES_SPAN_OTHER_NODES 1196 def_bool y 1197 depends on X86_64_ACPI_NUMA 1198 1199config NUMA_EMU 1200 bool "NUMA emulation" 1201 depends on X86_64 && NUMA 1202 ---help--- 1203 Enable NUMA emulation. A flat machine will be split 1204 into virtual nodes when booted with "numa=fake=N", where N is the 1205 number of nodes. This is only useful for debugging. 1206 1207config NODES_SHIFT 1208 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1209 range 1 10 1210 default "10" if MAXSMP 1211 default "6" if X86_64 1212 default "4" if X86_NUMAQ 1213 default "3" 1214 depends on NEED_MULTIPLE_NODES 1215 ---help--- 1216 Specify the maximum number of NUMA Nodes available on the target 1217 system. Increases memory reserved to accommodate various tables. 1218 1219config HAVE_ARCH_BOOTMEM 1220 def_bool y 1221 depends on X86_32 && NUMA 1222 1223config ARCH_HAVE_MEMORY_PRESENT 1224 def_bool y 1225 depends on X86_32 && DISCONTIGMEM 1226 1227config NEED_NODE_MEMMAP_SIZE 1228 def_bool y 1229 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1230 1231config HAVE_ARCH_ALLOC_REMAP 1232 def_bool y 1233 depends on X86_32 && NUMA 1234 1235config ARCH_FLATMEM_ENABLE 1236 def_bool y 1237 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA 1238 1239config ARCH_DISCONTIGMEM_ENABLE 1240 def_bool y 1241 depends on NUMA && X86_32 1242 1243config ARCH_DISCONTIGMEM_DEFAULT 1244 def_bool y 1245 depends on NUMA && X86_32 1246 1247config ARCH_PROC_KCORE_TEXT 1248 def_bool y 1249 depends on X86_64 && PROC_KCORE 1250 1251config ARCH_SPARSEMEM_DEFAULT 1252 def_bool y 1253 depends on X86_64 1254 1255config ARCH_SPARSEMEM_ENABLE 1256 def_bool y 1257 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD 1258 select SPARSEMEM_STATIC if X86_32 1259 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1260 1261config ARCH_SELECT_MEMORY_MODEL 1262 def_bool y 1263 depends on ARCH_SPARSEMEM_ENABLE 1264 1265config ARCH_MEMORY_PROBE 1266 def_bool X86_64 1267 depends on MEMORY_HOTPLUG 1268 1269config ILLEGAL_POINTER_VALUE 1270 hex 1271 default 0 if X86_32 1272 default 0xdead000000000000 if X86_64 1273 1274source "mm/Kconfig" 1275 1276config HIGHPTE 1277 bool "Allocate 3rd-level pagetables from highmem" 1278 depends on HIGHMEM 1279 ---help--- 1280 The VM uses one page table entry for each page of physical memory. 1281 For systems with a lot of RAM, this can be wasteful of precious 1282 low memory. Setting this option will put user-space page table 1283 entries in high memory. 1284 1285config X86_CHECK_BIOS_CORRUPTION 1286 bool "Check for low memory corruption" 1287 ---help--- 1288 Periodically check for memory corruption in low memory, which 1289 is suspected to be caused by BIOS. Even when enabled in the 1290 configuration, it is disabled at runtime. Enable it by 1291 setting "memory_corruption_check=1" on the kernel command 1292 line. By default it scans the low 64k of memory every 60 1293 seconds; see the memory_corruption_check_size and 1294 memory_corruption_check_period parameters in 1295 Documentation/kernel-parameters.txt to adjust this. 1296 1297 When enabled with the default parameters, this option has 1298 almost no overhead, as it reserves a relatively small amount 1299 of memory and scans it infrequently. It both detects corruption 1300 and prevents it from affecting the running system. 1301 1302 It is, however, intended as a diagnostic tool; if repeatable 1303 BIOS-originated corruption always affects the same memory, 1304 you can use memmap= to prevent the kernel from using that 1305 memory. 1306 1307config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1308 bool "Set the default setting of memory_corruption_check" 1309 depends on X86_CHECK_BIOS_CORRUPTION 1310 default y 1311 ---help--- 1312 Set whether the default state of memory_corruption_check is 1313 on or off. 1314 1315config X86_RESERVE_LOW 1316 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1317 default 64 1318 range 4 640 1319 ---help--- 1320 Specify the amount of low memory to reserve for the BIOS. 1321 1322 The first page contains BIOS data structures that the kernel 1323 must not use, so that page must always be reserved. 1324 1325 By default we reserve the first 64K of physical RAM, as a 1326 number of BIOSes are known to corrupt that memory range 1327 during events such as suspend/resume or monitor cable 1328 insertion, so it must not be used by the kernel. 1329 1330 You can set this to 4 if you are absolutely sure that you 1331 trust the BIOS to get all its memory reservations and usages 1332 right. If you know your BIOS have problems beyond the 1333 default 64K area, you can set this to 640 to avoid using the 1334 entire low memory range. 1335 1336 If you have doubts about the BIOS (e.g. suspend/resume does 1337 not work or there's kernel crashes after certain hardware 1338 hotplug events) then you might want to enable 1339 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1340 typical corruption patterns. 1341 1342 Leave this to the default value of 64 if you are unsure. 1343 1344config MATH_EMULATION 1345 bool 1346 prompt "Math emulation" if X86_32 1347 ---help--- 1348 Linux can emulate a math coprocessor (used for floating point 1349 operations) if you don't have one. 486DX and Pentium processors have 1350 a math coprocessor built in, 486SX and 386 do not, unless you added 1351 a 487DX or 387, respectively. (The messages during boot time can 1352 give you some hints here ["man dmesg"].) Everyone needs either a 1353 coprocessor or this emulation. 1354 1355 If you don't have a math coprocessor, you need to say Y here; if you 1356 say Y here even though you have a coprocessor, the coprocessor will 1357 be used nevertheless. (This behavior can be changed with the kernel 1358 command line option "no387", which comes handy if your coprocessor 1359 is broken. Try "man bootparam" or see the documentation of your boot 1360 loader (lilo or loadlin) about how to pass options to the kernel at 1361 boot time.) This means that it is a good idea to say Y here if you 1362 intend to use this kernel on different machines. 1363 1364 More information about the internals of the Linux math coprocessor 1365 emulation can be found in <file:arch/x86/math-emu/README>. 1366 1367 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1368 kernel, it won't hurt. 1369 1370config MTRR 1371 def_bool y 1372 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1373 ---help--- 1374 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1375 the Memory Type Range Registers (MTRRs) may be used to control 1376 processor access to memory ranges. This is most useful if you have 1377 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1378 allows bus write transfers to be combined into a larger transfer 1379 before bursting over the PCI/AGP bus. This can increase performance 1380 of image write operations 2.5 times or more. Saying Y here creates a 1381 /proc/mtrr file which may be used to manipulate your processor's 1382 MTRRs. Typically the X server should use this. 1383 1384 This code has a reasonably generic interface so that similar 1385 control registers on other processors can be easily supported 1386 as well: 1387 1388 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1389 Registers (ARRs) which provide a similar functionality to MTRRs. For 1390 these, the ARRs are used to emulate the MTRRs. 1391 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1392 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1393 write-combining. All of these processors are supported by this code 1394 and it makes sense to say Y here if you have one of them. 1395 1396 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1397 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1398 can lead to all sorts of problems, so it's good to say Y here. 1399 1400 You can safely say Y even if your machine doesn't have MTRRs, you'll 1401 just add about 9 KB to your kernel. 1402 1403 See <file:Documentation/x86/mtrr.txt> for more information. 1404 1405config MTRR_SANITIZER 1406 def_bool y 1407 prompt "MTRR cleanup support" 1408 depends on MTRR 1409 ---help--- 1410 Convert MTRR layout from continuous to discrete, so X drivers can 1411 add writeback entries. 1412 1413 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1414 The largest mtrr entry size for a continuous block can be set with 1415 mtrr_chunk_size. 1416 1417 If unsure, say Y. 1418 1419config MTRR_SANITIZER_ENABLE_DEFAULT 1420 int "MTRR cleanup enable value (0-1)" 1421 range 0 1 1422 default "0" 1423 depends on MTRR_SANITIZER 1424 ---help--- 1425 Enable mtrr cleanup default value 1426 1427config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1428 int "MTRR cleanup spare reg num (0-7)" 1429 range 0 7 1430 default "1" 1431 depends on MTRR_SANITIZER 1432 ---help--- 1433 mtrr cleanup spare entries default, it can be changed via 1434 mtrr_spare_reg_nr=N on the kernel command line. 1435 1436config X86_PAT 1437 def_bool y 1438 prompt "x86 PAT support" if EXPERT 1439 depends on MTRR 1440 ---help--- 1441 Use PAT attributes to setup page level cache control. 1442 1443 PATs are the modern equivalents of MTRRs and are much more 1444 flexible than MTRRs. 1445 1446 Say N here if you see bootup problems (boot crash, boot hang, 1447 spontaneous reboots) or a non-working video driver. 1448 1449 If unsure, say Y. 1450 1451config ARCH_USES_PG_UNCACHED 1452 def_bool y 1453 depends on X86_PAT 1454 1455config EFI 1456 bool "EFI runtime service support" 1457 depends on ACPI 1458 ---help--- 1459 This enables the kernel to use EFI runtime services that are 1460 available (such as the EFI variable services). 1461 1462 This option is only useful on systems that have EFI firmware. 1463 In addition, you should use the latest ELILO loader available 1464 at <http://elilo.sourceforge.net> in order to take advantage 1465 of EFI runtime services. However, even with this option, the 1466 resultant kernel should continue to boot on existing non-EFI 1467 platforms. 1468 1469config SECCOMP 1470 def_bool y 1471 prompt "Enable seccomp to safely compute untrusted bytecode" 1472 ---help--- 1473 This kernel feature is useful for number crunching applications 1474 that may need to compute untrusted bytecode during their 1475 execution. By using pipes or other transports made available to 1476 the process as file descriptors supporting the read/write 1477 syscalls, it's possible to isolate those applications in 1478 their own address space using seccomp. Once seccomp is 1479 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1480 and the task is only allowed to execute a few safe syscalls 1481 defined by each seccomp mode. 1482 1483 If unsure, say Y. Only embedded should say N here. 1484 1485config CC_STACKPROTECTOR 1486 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)" 1487 ---help--- 1488 This option turns on the -fstack-protector GCC feature. This 1489 feature puts, at the beginning of functions, a canary value on 1490 the stack just before the return address, and validates 1491 the value just before actually returning. Stack based buffer 1492 overflows (that need to overwrite this return address) now also 1493 overwrite the canary, which gets detected and the attack is then 1494 neutralized via a kernel panic. 1495 1496 This feature requires gcc version 4.2 or above, or a distribution 1497 gcc with the feature backported. Older versions are automatically 1498 detected and for those versions, this configuration option is 1499 ignored. (and a warning is printed during bootup) 1500 1501source kernel/Kconfig.hz 1502 1503config KEXEC 1504 bool "kexec system call" 1505 ---help--- 1506 kexec is a system call that implements the ability to shutdown your 1507 current kernel, and to start another kernel. It is like a reboot 1508 but it is independent of the system firmware. And like a reboot 1509 you can start any kernel with it, not just Linux. 1510 1511 The name comes from the similarity to the exec system call. 1512 1513 It is an ongoing process to be certain the hardware in a machine 1514 is properly shutdown, so do not be surprised if this code does not 1515 initially work for you. It may help to enable device hotplugging 1516 support. As of this writing the exact hardware interface is 1517 strongly in flux, so no good recommendation can be made. 1518 1519config CRASH_DUMP 1520 bool "kernel crash dumps" 1521 depends on X86_64 || (X86_32 && HIGHMEM) 1522 ---help--- 1523 Generate crash dump after being started by kexec. 1524 This should be normally only set in special crash dump kernels 1525 which are loaded in the main kernel with kexec-tools into 1526 a specially reserved region and then later executed after 1527 a crash by kdump/kexec. The crash dump kernel must be compiled 1528 to a memory address not used by the main kernel or BIOS using 1529 PHYSICAL_START, or it must be built as a relocatable image 1530 (CONFIG_RELOCATABLE=y). 1531 For more details see Documentation/kdump/kdump.txt 1532 1533config KEXEC_JUMP 1534 bool "kexec jump (EXPERIMENTAL)" 1535 depends on EXPERIMENTAL 1536 depends on KEXEC && HIBERNATION 1537 ---help--- 1538 Jump between original kernel and kexeced kernel and invoke 1539 code in physical address mode via KEXEC 1540 1541config PHYSICAL_START 1542 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1543 default "0x1000000" 1544 ---help--- 1545 This gives the physical address where the kernel is loaded. 1546 1547 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1548 bzImage will decompress itself to above physical address and 1549 run from there. Otherwise, bzImage will run from the address where 1550 it has been loaded by the boot loader and will ignore above physical 1551 address. 1552 1553 In normal kdump cases one does not have to set/change this option 1554 as now bzImage can be compiled as a completely relocatable image 1555 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1556 address. This option is mainly useful for the folks who don't want 1557 to use a bzImage for capturing the crash dump and want to use a 1558 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1559 to be specifically compiled to run from a specific memory area 1560 (normally a reserved region) and this option comes handy. 1561 1562 So if you are using bzImage for capturing the crash dump, 1563 leave the value here unchanged to 0x1000000 and set 1564 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1565 for capturing the crash dump change this value to start of 1566 the reserved region. In other words, it can be set based on 1567 the "X" value as specified in the "crashkernel=YM@XM" 1568 command line boot parameter passed to the panic-ed 1569 kernel. Please take a look at Documentation/kdump/kdump.txt 1570 for more details about crash dumps. 1571 1572 Usage of bzImage for capturing the crash dump is recommended as 1573 one does not have to build two kernels. Same kernel can be used 1574 as production kernel and capture kernel. Above option should have 1575 gone away after relocatable bzImage support is introduced. But it 1576 is present because there are users out there who continue to use 1577 vmlinux for dump capture. This option should go away down the 1578 line. 1579 1580 Don't change this unless you know what you are doing. 1581 1582config RELOCATABLE 1583 bool "Build a relocatable kernel" 1584 default y 1585 ---help--- 1586 This builds a kernel image that retains relocation information 1587 so it can be loaded someplace besides the default 1MB. 1588 The relocations tend to make the kernel binary about 10% larger, 1589 but are discarded at runtime. 1590 1591 One use is for the kexec on panic case where the recovery kernel 1592 must live at a different physical address than the primary 1593 kernel. 1594 1595 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1596 it has been loaded at and the compile time physical address 1597 (CONFIG_PHYSICAL_START) is ignored. 1598 1599# Relocation on x86-32 needs some additional build support 1600config X86_NEED_RELOCS 1601 def_bool y 1602 depends on X86_32 && RELOCATABLE 1603 1604config PHYSICAL_ALIGN 1605 hex "Alignment value to which kernel should be aligned" if X86_32 1606 default "0x1000000" 1607 range 0x2000 0x1000000 1608 ---help--- 1609 This value puts the alignment restrictions on physical address 1610 where kernel is loaded and run from. Kernel is compiled for an 1611 address which meets above alignment restriction. 1612 1613 If bootloader loads the kernel at a non-aligned address and 1614 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1615 address aligned to above value and run from there. 1616 1617 If bootloader loads the kernel at a non-aligned address and 1618 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1619 load address and decompress itself to the address it has been 1620 compiled for and run from there. The address for which kernel is 1621 compiled already meets above alignment restrictions. Hence the 1622 end result is that kernel runs from a physical address meeting 1623 above alignment restrictions. 1624 1625 Don't change this unless you know what you are doing. 1626 1627config HOTPLUG_CPU 1628 bool "Support for hot-pluggable CPUs" 1629 depends on SMP && HOTPLUG 1630 ---help--- 1631 Say Y here to allow turning CPUs off and on. CPUs can be 1632 controlled through /sys/devices/system/cpu. 1633 ( Note: power management support will enable this option 1634 automatically on SMP systems. ) 1635 Say N if you want to disable CPU hotplug. 1636 1637config COMPAT_VDSO 1638 def_bool y 1639 prompt "Compat VDSO support" 1640 depends on X86_32 || IA32_EMULATION 1641 ---help--- 1642 Map the 32-bit VDSO to the predictable old-style address too. 1643 1644 Say N here if you are running a sufficiently recent glibc 1645 version (2.3.3 or later), to remove the high-mapped 1646 VDSO mapping and to exclusively use the randomized VDSO. 1647 1648 If unsure, say Y. 1649 1650config CMDLINE_BOOL 1651 bool "Built-in kernel command line" 1652 ---help--- 1653 Allow for specifying boot arguments to the kernel at 1654 build time. On some systems (e.g. embedded ones), it is 1655 necessary or convenient to provide some or all of the 1656 kernel boot arguments with the kernel itself (that is, 1657 to not rely on the boot loader to provide them.) 1658 1659 To compile command line arguments into the kernel, 1660 set this option to 'Y', then fill in the 1661 the boot arguments in CONFIG_CMDLINE. 1662 1663 Systems with fully functional boot loaders (i.e. non-embedded) 1664 should leave this option set to 'N'. 1665 1666config CMDLINE 1667 string "Built-in kernel command string" 1668 depends on CMDLINE_BOOL 1669 default "" 1670 ---help--- 1671 Enter arguments here that should be compiled into the kernel 1672 image and used at boot time. If the boot loader provides a 1673 command line at boot time, it is appended to this string to 1674 form the full kernel command line, when the system boots. 1675 1676 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1677 change this behavior. 1678 1679 In most cases, the command line (whether built-in or provided 1680 by the boot loader) should specify the device for the root 1681 file system. 1682 1683config CMDLINE_OVERRIDE 1684 bool "Built-in command line overrides boot loader arguments" 1685 depends on CMDLINE_BOOL 1686 ---help--- 1687 Set this option to 'Y' to have the kernel ignore the boot loader 1688 command line, and use ONLY the built-in command line. 1689 1690 This is used to work around broken boot loaders. This should 1691 be set to 'N' under normal conditions. 1692 1693endmenu 1694 1695config ARCH_ENABLE_MEMORY_HOTPLUG 1696 def_bool y 1697 depends on X86_64 || (X86_32 && HIGHMEM) 1698 1699config ARCH_ENABLE_MEMORY_HOTREMOVE 1700 def_bool y 1701 depends on MEMORY_HOTPLUG 1702 1703config HAVE_ARCH_EARLY_PFN_TO_NID 1704 def_bool X86_64 1705 depends on NUMA 1706 1707config USE_PERCPU_NUMA_NODE_ID 1708 def_bool X86_64 1709 depends on NUMA 1710 1711menu "Power management and ACPI options" 1712 1713config ARCH_HIBERNATION_HEADER 1714 def_bool y 1715 depends on X86_64 && HIBERNATION 1716 1717source "kernel/power/Kconfig" 1718 1719source "drivers/acpi/Kconfig" 1720 1721source "drivers/sfi/Kconfig" 1722 1723config X86_APM_BOOT 1724 def_bool y 1725 depends on APM || APM_MODULE 1726 1727menuconfig APM 1728 tristate "APM (Advanced Power Management) BIOS support" 1729 depends on X86_32 && PM_SLEEP 1730 ---help--- 1731 APM is a BIOS specification for saving power using several different 1732 techniques. This is mostly useful for battery powered laptops with 1733 APM compliant BIOSes. If you say Y here, the system time will be 1734 reset after a RESUME operation, the /proc/apm device will provide 1735 battery status information, and user-space programs will receive 1736 notification of APM "events" (e.g. battery status change). 1737 1738 If you select "Y" here, you can disable actual use of the APM 1739 BIOS by passing the "apm=off" option to the kernel at boot time. 1740 1741 Note that the APM support is almost completely disabled for 1742 machines with more than one CPU. 1743 1744 In order to use APM, you will need supporting software. For location 1745 and more information, read <file:Documentation/power/pm.txt> and the 1746 Battery Powered Linux mini-HOWTO, available from 1747 <http://www.tldp.org/docs.html#howto>. 1748 1749 This driver does not spin down disk drives (see the hdparm(8) 1750 manpage ("man 8 hdparm") for that), and it doesn't turn off 1751 VESA-compliant "green" monitors. 1752 1753 This driver does not support the TI 4000M TravelMate and the ACER 1754 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1755 desktop machines also don't have compliant BIOSes, and this driver 1756 may cause those machines to panic during the boot phase. 1757 1758 Generally, if you don't have a battery in your machine, there isn't 1759 much point in using this driver and you should say N. If you get 1760 random kernel OOPSes or reboots that don't seem to be related to 1761 anything, try disabling/enabling this option (or disabling/enabling 1762 APM in your BIOS). 1763 1764 Some other things you should try when experiencing seemingly random, 1765 "weird" problems: 1766 1767 1) make sure that you have enough swap space and that it is 1768 enabled. 1769 2) pass the "no-hlt" option to the kernel 1770 3) switch on floating point emulation in the kernel and pass 1771 the "no387" option to the kernel 1772 4) pass the "floppy=nodma" option to the kernel 1773 5) pass the "mem=4M" option to the kernel (thereby disabling 1774 all but the first 4 MB of RAM) 1775 6) make sure that the CPU is not over clocked. 1776 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1777 8) disable the cache from your BIOS settings 1778 9) install a fan for the video card or exchange video RAM 1779 10) install a better fan for the CPU 1780 11) exchange RAM chips 1781 12) exchange the motherboard. 1782 1783 To compile this driver as a module, choose M here: the 1784 module will be called apm. 1785 1786if APM 1787 1788config APM_IGNORE_USER_SUSPEND 1789 bool "Ignore USER SUSPEND" 1790 ---help--- 1791 This option will ignore USER SUSPEND requests. On machines with a 1792 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1793 series notebooks, it is necessary to say Y because of a BIOS bug. 1794 1795config APM_DO_ENABLE 1796 bool "Enable PM at boot time" 1797 ---help--- 1798 Enable APM features at boot time. From page 36 of the APM BIOS 1799 specification: "When disabled, the APM BIOS does not automatically 1800 power manage devices, enter the Standby State, enter the Suspend 1801 State, or take power saving steps in response to CPU Idle calls." 1802 This driver will make CPU Idle calls when Linux is idle (unless this 1803 feature is turned off -- see "Do CPU IDLE calls", below). This 1804 should always save battery power, but more complicated APM features 1805 will be dependent on your BIOS implementation. You may need to turn 1806 this option off if your computer hangs at boot time when using APM 1807 support, or if it beeps continuously instead of suspending. Turn 1808 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1809 T400CDT. This is off by default since most machines do fine without 1810 this feature. 1811 1812config APM_CPU_IDLE 1813 bool "Make CPU Idle calls when idle" 1814 ---help--- 1815 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1816 On some machines, this can activate improved power savings, such as 1817 a slowed CPU clock rate, when the machine is idle. These idle calls 1818 are made after the idle loop has run for some length of time (e.g., 1819 333 mS). On some machines, this will cause a hang at boot time or 1820 whenever the CPU becomes idle. (On machines with more than one CPU, 1821 this option does nothing.) 1822 1823config APM_DISPLAY_BLANK 1824 bool "Enable console blanking using APM" 1825 ---help--- 1826 Enable console blanking using the APM. Some laptops can use this to 1827 turn off the LCD backlight when the screen blanker of the Linux 1828 virtual console blanks the screen. Note that this is only used by 1829 the virtual console screen blanker, and won't turn off the backlight 1830 when using the X Window system. This also doesn't have anything to 1831 do with your VESA-compliant power-saving monitor. Further, this 1832 option doesn't work for all laptops -- it might not turn off your 1833 backlight at all, or it might print a lot of errors to the console, 1834 especially if you are using gpm. 1835 1836config APM_ALLOW_INTS 1837 bool "Allow interrupts during APM BIOS calls" 1838 ---help--- 1839 Normally we disable external interrupts while we are making calls to 1840 the APM BIOS as a measure to lessen the effects of a badly behaving 1841 BIOS implementation. The BIOS should reenable interrupts if it 1842 needs to. Unfortunately, some BIOSes do not -- especially those in 1843 many of the newer IBM Thinkpads. If you experience hangs when you 1844 suspend, try setting this to Y. Otherwise, say N. 1845 1846endif # APM 1847 1848source "arch/x86/kernel/cpu/cpufreq/Kconfig" 1849 1850source "drivers/cpuidle/Kconfig" 1851 1852source "drivers/idle/Kconfig" 1853 1854endmenu 1855 1856 1857menu "Bus options (PCI etc.)" 1858 1859config PCI 1860 bool "PCI support" 1861 default y 1862 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC) 1863 ---help--- 1864 Find out whether you have a PCI motherboard. PCI is the name of a 1865 bus system, i.e. the way the CPU talks to the other stuff inside 1866 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 1867 VESA. If you have PCI, say Y, otherwise N. 1868 1869choice 1870 prompt "PCI access mode" 1871 depends on X86_32 && PCI 1872 default PCI_GOANY 1873 ---help--- 1874 On PCI systems, the BIOS can be used to detect the PCI devices and 1875 determine their configuration. However, some old PCI motherboards 1876 have BIOS bugs and may crash if this is done. Also, some embedded 1877 PCI-based systems don't have any BIOS at all. Linux can also try to 1878 detect the PCI hardware directly without using the BIOS. 1879 1880 With this option, you can specify how Linux should detect the 1881 PCI devices. If you choose "BIOS", the BIOS will be used, 1882 if you choose "Direct", the BIOS won't be used, and if you 1883 choose "MMConfig", then PCI Express MMCONFIG will be used. 1884 If you choose "Any", the kernel will try MMCONFIG, then the 1885 direct access method and falls back to the BIOS if that doesn't 1886 work. If unsure, go with the default, which is "Any". 1887 1888config PCI_GOBIOS 1889 bool "BIOS" 1890 1891config PCI_GOMMCONFIG 1892 bool "MMConfig" 1893 1894config PCI_GODIRECT 1895 bool "Direct" 1896 1897config PCI_GOOLPC 1898 bool "OLPC XO-1" 1899 depends on OLPC 1900 1901config PCI_GOANY 1902 bool "Any" 1903 1904endchoice 1905 1906config PCI_BIOS 1907 def_bool y 1908 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 1909 1910# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 1911config PCI_DIRECT 1912 def_bool y 1913 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC)) 1914 1915config PCI_MMCONFIG 1916 def_bool y 1917 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 1918 1919config PCI_OLPC 1920 def_bool y 1921 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 1922 1923config PCI_XEN 1924 def_bool y 1925 depends on PCI && XEN 1926 select SWIOTLB_XEN 1927 1928config PCI_DOMAINS 1929 def_bool y 1930 depends on PCI 1931 1932config PCI_MMCONFIG 1933 bool "Support mmconfig PCI config space access" 1934 depends on X86_64 && PCI && ACPI 1935 1936config PCI_CNB20LE_QUIRK 1937 bool "Read CNB20LE Host Bridge Windows" if EXPERT 1938 default n 1939 depends on PCI && EXPERIMENTAL 1940 help 1941 Read the PCI windows out of the CNB20LE host bridge. This allows 1942 PCI hotplug to work on systems with the CNB20LE chipset which do 1943 not have ACPI. 1944 1945 There's no public spec for this chipset, and this functionality 1946 is known to be incomplete. 1947 1948 You should say N unless you know you need this. 1949 1950config DMAR 1951 bool "Support for DMA Remapping Devices (EXPERIMENTAL)" 1952 depends on PCI_MSI && ACPI && EXPERIMENTAL 1953 help 1954 DMA remapping (DMAR) devices support enables independent address 1955 translations for Direct Memory Access (DMA) from devices. 1956 These DMA remapping devices are reported via ACPI tables 1957 and include PCI device scope covered by these DMA 1958 remapping devices. 1959 1960config DMAR_DEFAULT_ON 1961 def_bool y 1962 prompt "Enable DMA Remapping Devices by default" 1963 depends on DMAR 1964 help 1965 Selecting this option will enable a DMAR device at boot time if 1966 one is found. If this option is not selected, DMAR support can 1967 be enabled by passing intel_iommu=on to the kernel. It is 1968 recommended you say N here while the DMAR code remains 1969 experimental. 1970 1971config DMAR_BROKEN_GFX_WA 1972 bool "Workaround broken graphics drivers (going away soon)" 1973 depends on DMAR && BROKEN 1974 ---help--- 1975 Current Graphics drivers tend to use physical address 1976 for DMA and avoid using DMA APIs. Setting this config 1977 option permits the IOMMU driver to set a unity map for 1978 all the OS-visible memory. Hence the driver can continue 1979 to use physical addresses for DMA, at least until this 1980 option is removed in the 2.6.32 kernel. 1981 1982config DMAR_FLOPPY_WA 1983 def_bool y 1984 depends on DMAR 1985 ---help--- 1986 Floppy disk drivers are known to bypass DMA API calls 1987 thereby failing to work when IOMMU is enabled. This 1988 workaround will setup a 1:1 mapping for the first 1989 16MiB to make floppy (an ISA device) work. 1990 1991config INTR_REMAP 1992 bool "Support for Interrupt Remapping (EXPERIMENTAL)" 1993 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL 1994 ---help--- 1995 Supports Interrupt remapping for IO-APIC and MSI devices. 1996 To use x2apic mode in the CPU's which support x2APIC enhancements or 1997 to support platforms with CPU's having > 8 bit APIC ID, say Y. 1998 1999source "drivers/pci/pcie/Kconfig" 2000 2001source "drivers/pci/Kconfig" 2002 2003# x86_64 have no ISA slots, but do have ISA-style DMA. 2004config ISA_DMA_API 2005 def_bool y 2006 2007if X86_32 2008 2009config ISA 2010 bool "ISA support" 2011 ---help--- 2012 Find out whether you have ISA slots on your motherboard. ISA is the 2013 name of a bus system, i.e. the way the CPU talks to the other stuff 2014 inside your box. Other bus systems are PCI, EISA, MicroChannel 2015 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2016 newer boards don't support it. If you have ISA, say Y, otherwise N. 2017 2018config EISA 2019 bool "EISA support" 2020 depends on ISA 2021 ---help--- 2022 The Extended Industry Standard Architecture (EISA) bus was 2023 developed as an open alternative to the IBM MicroChannel bus. 2024 2025 The EISA bus provided some of the features of the IBM MicroChannel 2026 bus while maintaining backward compatibility with cards made for 2027 the older ISA bus. The EISA bus saw limited use between 1988 and 2028 1995 when it was made obsolete by the PCI bus. 2029 2030 Say Y here if you are building a kernel for an EISA-based machine. 2031 2032 Otherwise, say N. 2033 2034source "drivers/eisa/Kconfig" 2035 2036config MCA 2037 bool "MCA support" 2038 ---help--- 2039 MicroChannel Architecture is found in some IBM PS/2 machines and 2040 laptops. It is a bus system similar to PCI or ISA. See 2041 <file:Documentation/mca.txt> (and especially the web page given 2042 there) before attempting to build an MCA bus kernel. 2043 2044source "drivers/mca/Kconfig" 2045 2046config SCx200 2047 tristate "NatSemi SCx200 support" 2048 ---help--- 2049 This provides basic support for National Semiconductor's 2050 (now AMD's) Geode processors. The driver probes for the 2051 PCI-IDs of several on-chip devices, so its a good dependency 2052 for other scx200_* drivers. 2053 2054 If compiled as a module, the driver is named scx200. 2055 2056config SCx200HR_TIMER 2057 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2058 depends on SCx200 2059 default y 2060 ---help--- 2061 This driver provides a clocksource built upon the on-chip 2062 27MHz high-resolution timer. Its also a workaround for 2063 NSC Geode SC-1100's buggy TSC, which loses time when the 2064 processor goes idle (as is done by the scheduler). The 2065 other workaround is idle=poll boot option. 2066 2067config OLPC 2068 bool "One Laptop Per Child support" 2069 select GPIOLIB 2070 select OLPC_OPENFIRMWARE 2071 depends on !X86_64 && !X86_PAE 2072 ---help--- 2073 Add support for detecting the unique features of the OLPC 2074 XO hardware. 2075 2076config OLPC_XO1 2077 tristate "OLPC XO-1 support" 2078 depends on OLPC && MFD_CS5535 2079 ---help--- 2080 Add support for non-essential features of the OLPC XO-1 laptop. 2081 2082config OLPC_OPENFIRMWARE 2083 bool "Support for OLPC's Open Firmware" 2084 depends on !X86_64 && !X86_PAE 2085 default n 2086 select OF 2087 help 2088 This option adds support for the implementation of Open Firmware 2089 that is used on the OLPC XO-1 Children's Machine. 2090 If unsure, say N here. 2091 2092config OLPC_OPENFIRMWARE_DT 2093 bool 2094 default y if OLPC_OPENFIRMWARE && PROC_DEVICETREE 2095 select OF_PROMTREE 2096 2097endif # X86_32 2098 2099config AMD_NB 2100 def_bool y 2101 depends on CPU_SUP_AMD && PCI 2102 2103source "drivers/pcmcia/Kconfig" 2104 2105source "drivers/pci/hotplug/Kconfig" 2106 2107endmenu 2108 2109 2110menu "Executable file formats / Emulations" 2111 2112source "fs/Kconfig.binfmt" 2113 2114config IA32_EMULATION 2115 bool "IA32 Emulation" 2116 depends on X86_64 2117 select COMPAT_BINFMT_ELF 2118 ---help--- 2119 Include code to run 32-bit programs under a 64-bit kernel. You should 2120 likely turn this on, unless you're 100% sure that you don't have any 2121 32-bit programs left. 2122 2123config IA32_AOUT 2124 tristate "IA32 a.out support" 2125 depends on IA32_EMULATION 2126 ---help--- 2127 Support old a.out binaries in the 32bit emulation. 2128 2129config COMPAT 2130 def_bool y 2131 depends on IA32_EMULATION 2132 2133config COMPAT_FOR_U64_ALIGNMENT 2134 def_bool COMPAT 2135 depends on X86_64 2136 2137config SYSVIPC_COMPAT 2138 def_bool y 2139 depends on COMPAT && SYSVIPC 2140 2141endmenu 2142 2143 2144config HAVE_ATOMIC_IOMAP 2145 def_bool y 2146 depends on X86_32 2147 2148config HAVE_TEXT_POKE_SMP 2149 bool 2150 select STOP_MACHINE if SMP 2151 2152source "net/Kconfig" 2153 2154source "drivers/Kconfig" 2155 2156source "drivers/firmware/Kconfig" 2157 2158source "fs/Kconfig" 2159 2160source "arch/x86/Kconfig.debug" 2161 2162source "security/Kconfig" 2163 2164source "crypto/Kconfig" 2165 2166source "arch/x86/kvm/Kconfig" 2167 2168source "lib/Kconfig" 2169